1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bitmap.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/interrupt.h>
6 #include <linux/irq.h>
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/debugfs.h>
12 #include <linux/seq_file.h>
13 #include <linux/gpio.h>
14 #include <linux/idr.h>
15 #include <linux/slab.h>
16 #include <linux/acpi.h>
17 #include <linux/gpio/driver.h>
18 #include <linux/gpio/machine.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/fs.h>
21 #include <linux/compat.h>
22 #include <linux/file.h>
23 #include <uapi/linux/gpio.h>
24
25 #include "gpiolib.h"
26 #include "gpiolib-of.h"
27 #include "gpiolib-acpi.h"
28 #include "gpiolib-cdev.h"
29 #include "gpiolib-sysfs.h"
30
31 #define CREATE_TRACE_POINTS
32 #include <trace/events/gpio.h>
33
34 /* Implementation infrastructure for GPIO interfaces.
35 *
36 * The GPIO programming interface allows for inlining speed-critical
37 * get/set operations for common cases, so that access to SOC-integrated
38 * GPIOs can sometimes cost only an instruction or two per bit.
39 */
40
41
42 /* When debugging, extend minimal trust to callers and platform code.
43 * Also emit diagnostic messages that may help initial bringup, when
44 * board setup or driver bugs are most common.
45 *
46 * Otherwise, minimize overhead in what may be bitbanging codepaths.
47 */
48 #ifdef DEBUG
49 #define extra_checks 1
50 #else
51 #define extra_checks 0
52 #endif
53
54 /* Device and char device-related information */
55 static DEFINE_IDA(gpio_ida);
56 static dev_t gpio_devt;
57 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
58 static struct bus_type gpio_bus_type = {
59 .name = "gpio",
60 };
61
62 /*
63 * Number of GPIOs to use for the fast path in set array
64 */
65 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
66
67 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
68 * While any GPIO is requested, its gpio_chip is not removable;
69 * each GPIO's "requested" flag serves as a lock and refcount.
70 */
71 DEFINE_SPINLOCK(gpio_lock);
72
73 static DEFINE_MUTEX(gpio_lookup_lock);
74 static LIST_HEAD(gpio_lookup_list);
75 LIST_HEAD(gpio_devices);
76
77 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
78 static LIST_HEAD(gpio_machine_hogs);
79
80 static void gpiochip_free_hogs(struct gpio_chip *gc);
81 static int gpiochip_add_irqchip(struct gpio_chip *gc,
82 struct lock_class_key *lock_key,
83 struct lock_class_key *request_key);
84 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
85 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
86 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
87 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
88
89 static bool gpiolib_initialized;
90
desc_set_label(struct gpio_desc * d,const char * label)91 static inline void desc_set_label(struct gpio_desc *d, const char *label)
92 {
93 d->label = label;
94 }
95
96 /**
97 * gpio_to_desc - Convert a GPIO number to its descriptor
98 * @gpio: global GPIO number
99 *
100 * Returns:
101 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
102 * with the given number exists in the system.
103 */
gpio_to_desc(unsigned gpio)104 struct gpio_desc *gpio_to_desc(unsigned gpio)
105 {
106 struct gpio_device *gdev;
107 unsigned long flags;
108
109 spin_lock_irqsave(&gpio_lock, flags);
110
111 list_for_each_entry(gdev, &gpio_devices, list) {
112 if (gdev->base <= gpio &&
113 gdev->base + gdev->ngpio > gpio) {
114 spin_unlock_irqrestore(&gpio_lock, flags);
115 return &gdev->descs[gpio - gdev->base];
116 }
117 }
118
119 spin_unlock_irqrestore(&gpio_lock, flags);
120
121 if (!gpio_is_valid(gpio))
122 WARN(1, "invalid GPIO %d\n", gpio);
123
124 return NULL;
125 }
126 EXPORT_SYMBOL_GPL(gpio_to_desc);
127
128 /**
129 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
130 * hardware number for this chip
131 * @gc: GPIO chip
132 * @hwnum: hardware number of the GPIO for this chip
133 *
134 * Returns:
135 * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
136 * in the given chip for the specified hardware number.
137 */
gpiochip_get_desc(struct gpio_chip * gc,unsigned int hwnum)138 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
139 unsigned int hwnum)
140 {
141 struct gpio_device *gdev = gc->gpiodev;
142
143 if (hwnum >= gdev->ngpio)
144 return ERR_PTR(-EINVAL);
145
146 return &gdev->descs[hwnum];
147 }
148 EXPORT_SYMBOL_GPL(gpiochip_get_desc);
149
150 /**
151 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
152 * @desc: GPIO descriptor
153 *
154 * This should disappear in the future but is needed since we still
155 * use GPIO numbers for error messages and sysfs nodes.
156 *
157 * Returns:
158 * The global GPIO number for the GPIO specified by its descriptor.
159 */
desc_to_gpio(const struct gpio_desc * desc)160 int desc_to_gpio(const struct gpio_desc *desc)
161 {
162 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
163 }
164 EXPORT_SYMBOL_GPL(desc_to_gpio);
165
166
167 /**
168 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
169 * @desc: descriptor to return the chip of
170 */
gpiod_to_chip(const struct gpio_desc * desc)171 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
172 {
173 if (!desc || !desc->gdev)
174 return NULL;
175 return desc->gdev->chip;
176 }
177 EXPORT_SYMBOL_GPL(gpiod_to_chip);
178
179 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
gpiochip_find_base(int ngpio)180 static int gpiochip_find_base(int ngpio)
181 {
182 struct gpio_device *gdev;
183 int base = ARCH_NR_GPIOS - ngpio;
184
185 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
186 /* found a free space? */
187 if (gdev->base + gdev->ngpio <= base)
188 break;
189 /* nope, check the space right before the chip */
190 base = gdev->base - ngpio;
191 }
192
193 if (gpio_is_valid(base)) {
194 pr_debug("%s: found new base at %d\n", __func__, base);
195 return base;
196 } else {
197 pr_err("%s: cannot find free range\n", __func__);
198 return -ENOSPC;
199 }
200 }
201
202 /**
203 * gpiod_get_direction - return the current direction of a GPIO
204 * @desc: GPIO to get the direction of
205 *
206 * Returns 0 for output, 1 for input, or an error code in case of error.
207 *
208 * This function may sleep if gpiod_cansleep() is true.
209 */
gpiod_get_direction(struct gpio_desc * desc)210 int gpiod_get_direction(struct gpio_desc *desc)
211 {
212 struct gpio_chip *gc;
213 unsigned offset;
214 int ret;
215
216 gc = gpiod_to_chip(desc);
217 offset = gpio_chip_hwgpio(desc);
218
219 /*
220 * Open drain emulation using input mode may incorrectly report
221 * input here, fix that up.
222 */
223 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
224 test_bit(FLAG_IS_OUT, &desc->flags))
225 return 0;
226
227 if (!gc->get_direction)
228 return -ENOTSUPP;
229
230 ret = gc->get_direction(gc, offset);
231 if (ret < 0)
232 return ret;
233
234 /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
235 if (ret > 0)
236 ret = 1;
237
238 assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
239
240 return ret;
241 }
242 EXPORT_SYMBOL_GPL(gpiod_get_direction);
243
244 /*
245 * Add a new chip to the global chips list, keeping the list of chips sorted
246 * by range(means [base, base + ngpio - 1]) order.
247 *
248 * Return -EBUSY if the new chip overlaps with some other chip's integer
249 * space.
250 */
gpiodev_add_to_list(struct gpio_device * gdev)251 static int gpiodev_add_to_list(struct gpio_device *gdev)
252 {
253 struct gpio_device *prev, *next;
254
255 if (list_empty(&gpio_devices)) {
256 /* initial entry in list */
257 list_add_tail(&gdev->list, &gpio_devices);
258 return 0;
259 }
260
261 next = list_entry(gpio_devices.next, struct gpio_device, list);
262 if (gdev->base + gdev->ngpio <= next->base) {
263 /* add before first entry */
264 list_add(&gdev->list, &gpio_devices);
265 return 0;
266 }
267
268 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
269 if (prev->base + prev->ngpio <= gdev->base) {
270 /* add behind last entry */
271 list_add_tail(&gdev->list, &gpio_devices);
272 return 0;
273 }
274
275 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
276 /* at the end of the list */
277 if (&next->list == &gpio_devices)
278 break;
279
280 /* add between prev and next */
281 if (prev->base + prev->ngpio <= gdev->base
282 && gdev->base + gdev->ngpio <= next->base) {
283 list_add(&gdev->list, &prev->list);
284 return 0;
285 }
286 }
287
288 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
289 return -EBUSY;
290 }
291
292 /*
293 * Convert a GPIO name to its descriptor
294 * Note that there is no guarantee that GPIO names are globally unique!
295 * Hence this function will return, if it exists, a reference to the first GPIO
296 * line found that matches the given name.
297 */
gpio_name_to_desc(const char * const name)298 static struct gpio_desc *gpio_name_to_desc(const char * const name)
299 {
300 struct gpio_device *gdev;
301 unsigned long flags;
302
303 if (!name)
304 return NULL;
305
306 spin_lock_irqsave(&gpio_lock, flags);
307
308 list_for_each_entry(gdev, &gpio_devices, list) {
309 int i;
310
311 for (i = 0; i != gdev->ngpio; ++i) {
312 struct gpio_desc *desc = &gdev->descs[i];
313
314 if (!desc->name)
315 continue;
316
317 if (!strcmp(desc->name, name)) {
318 spin_unlock_irqrestore(&gpio_lock, flags);
319 return desc;
320 }
321 }
322 }
323
324 spin_unlock_irqrestore(&gpio_lock, flags);
325
326 return NULL;
327 }
328
329 /*
330 * Take the names from gc->names and assign them to their GPIO descriptors.
331 * Warn if a name is already used for a GPIO line on a different GPIO chip.
332 *
333 * Note that:
334 * 1. Non-unique names are still accepted,
335 * 2. Name collisions within the same GPIO chip are not reported.
336 */
gpiochip_set_desc_names(struct gpio_chip * gc)337 static int gpiochip_set_desc_names(struct gpio_chip *gc)
338 {
339 struct gpio_device *gdev = gc->gpiodev;
340 int i;
341
342 /* First check all names if they are unique */
343 for (i = 0; i != gc->ngpio; ++i) {
344 struct gpio_desc *gpio;
345
346 gpio = gpio_name_to_desc(gc->names[i]);
347 if (gpio)
348 dev_warn(&gdev->dev,
349 "Detected name collision for GPIO name '%s'\n",
350 gc->names[i]);
351 }
352
353 /* Then add all names to the GPIO descriptors */
354 for (i = 0; i != gc->ngpio; ++i)
355 gdev->descs[i].name = gc->names[i];
356
357 return 0;
358 }
359
360 /*
361 * devprop_gpiochip_set_names - Set GPIO line names using device properties
362 * @chip: GPIO chip whose lines should be named, if possible
363 *
364 * Looks for device property "gpio-line-names" and if it exists assigns
365 * GPIO line names for the chip. The memory allocated for the assigned
366 * names belong to the underlying firmware node and should not be released
367 * by the caller.
368 */
devprop_gpiochip_set_names(struct gpio_chip * chip)369 static int devprop_gpiochip_set_names(struct gpio_chip *chip)
370 {
371 struct gpio_device *gdev = chip->gpiodev;
372 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
373 const char **names;
374 int ret, i;
375 int count;
376
377 count = fwnode_property_string_array_count(fwnode, "gpio-line-names");
378 if (count < 0)
379 return 0;
380
381 if (count > gdev->ngpio) {
382 dev_warn(&gdev->dev, "gpio-line-names is length %d but should be at most length %d",
383 count, gdev->ngpio);
384 count = gdev->ngpio;
385 }
386
387 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
388 if (!names)
389 return -ENOMEM;
390
391 ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
392 names, count);
393 if (ret < 0) {
394 dev_warn(&gdev->dev, "failed to read GPIO line names\n");
395 kfree(names);
396 return ret;
397 }
398
399 for (i = 0; i < count; i++)
400 gdev->descs[i].name = names[i];
401
402 kfree(names);
403
404 return 0;
405 }
406
gpiochip_allocate_mask(struct gpio_chip * gc)407 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
408 {
409 unsigned long *p;
410
411 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
412 if (!p)
413 return NULL;
414
415 /* Assume by default all GPIOs are valid */
416 bitmap_fill(p, gc->ngpio);
417
418 return p;
419 }
420
gpiochip_alloc_valid_mask(struct gpio_chip * gc)421 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
422 {
423 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
424 return 0;
425
426 gc->valid_mask = gpiochip_allocate_mask(gc);
427 if (!gc->valid_mask)
428 return -ENOMEM;
429
430 return 0;
431 }
432
gpiochip_init_valid_mask(struct gpio_chip * gc)433 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
434 {
435 if (gc->init_valid_mask)
436 return gc->init_valid_mask(gc,
437 gc->valid_mask,
438 gc->ngpio);
439
440 return 0;
441 }
442
gpiochip_free_valid_mask(struct gpio_chip * gc)443 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
444 {
445 bitmap_free(gc->valid_mask);
446 gc->valid_mask = NULL;
447 }
448
gpiochip_add_pin_ranges(struct gpio_chip * gc)449 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
450 {
451 if (gc->add_pin_ranges)
452 return gc->add_pin_ranges(gc);
453
454 return 0;
455 }
456
gpiochip_line_is_valid(const struct gpio_chip * gc,unsigned int offset)457 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
458 unsigned int offset)
459 {
460 /* No mask means all valid */
461 if (likely(!gc->valid_mask))
462 return true;
463 return test_bit(offset, gc->valid_mask);
464 }
465 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
466
gpiodevice_release(struct device * dev)467 static void gpiodevice_release(struct device *dev)
468 {
469 struct gpio_device *gdev = dev_get_drvdata(dev);
470 unsigned long flags;
471
472 spin_lock_irqsave(&gpio_lock, flags);
473 list_del(&gdev->list);
474 spin_unlock_irqrestore(&gpio_lock, flags);
475
476 ida_free(&gpio_ida, gdev->id);
477 kfree_const(gdev->label);
478 kfree(gdev->descs);
479 kfree(gdev);
480 }
481
482 #ifdef CONFIG_GPIO_CDEV
483 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
484 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
485 #else
486 /*
487 * gpiolib_cdev_register() indirectly calls device_add(), which is still
488 * required even when cdev is not selected.
489 */
490 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
491 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
492 #endif
493
gpiochip_setup_dev(struct gpio_device * gdev)494 static int gpiochip_setup_dev(struct gpio_device *gdev)
495 {
496 int ret;
497
498 ret = gcdev_register(gdev, gpio_devt);
499 if (ret)
500 return ret;
501
502 ret = gpiochip_sysfs_register(gdev);
503 if (ret)
504 goto err_remove_device;
505
506 /* From this point, the .release() function cleans up gpio_device */
507 gdev->dev.release = gpiodevice_release;
508 dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
509 gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
510
511 return 0;
512
513 err_remove_device:
514 gcdev_unregister(gdev);
515 return ret;
516 }
517
gpiochip_machine_hog(struct gpio_chip * gc,struct gpiod_hog * hog)518 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
519 {
520 struct gpio_desc *desc;
521 int rv;
522
523 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
524 if (IS_ERR(desc)) {
525 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
526 PTR_ERR(desc));
527 return;
528 }
529
530 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
531 return;
532
533 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
534 if (rv)
535 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
536 __func__, gc->label, hog->chip_hwnum, rv);
537 }
538
machine_gpiochip_add(struct gpio_chip * gc)539 static void machine_gpiochip_add(struct gpio_chip *gc)
540 {
541 struct gpiod_hog *hog;
542
543 mutex_lock(&gpio_machine_hogs_mutex);
544
545 list_for_each_entry(hog, &gpio_machine_hogs, list) {
546 if (!strcmp(gc->label, hog->chip_label))
547 gpiochip_machine_hog(gc, hog);
548 }
549
550 mutex_unlock(&gpio_machine_hogs_mutex);
551 }
552
gpiochip_setup_devs(void)553 static void gpiochip_setup_devs(void)
554 {
555 struct gpio_device *gdev;
556 int ret;
557
558 list_for_each_entry(gdev, &gpio_devices, list) {
559 ret = gpiochip_setup_dev(gdev);
560 if (ret)
561 dev_err(&gdev->dev,
562 "Failed to initialize gpio device (%d)\n", ret);
563 }
564 }
565
gpiochip_add_data_with_key(struct gpio_chip * gc,void * data,struct lock_class_key * lock_key,struct lock_class_key * request_key)566 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
567 struct lock_class_key *lock_key,
568 struct lock_class_key *request_key)
569 {
570 struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
571 unsigned long flags;
572 int ret = 0;
573 unsigned i;
574 int base = gc->base;
575 struct gpio_device *gdev;
576
577 /*
578 * First: allocate and populate the internal stat container, and
579 * set up the struct device.
580 */
581 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
582 if (!gdev)
583 return -ENOMEM;
584 gdev->dev.bus = &gpio_bus_type;
585 gdev->chip = gc;
586 gc->gpiodev = gdev;
587 if (gc->parent) {
588 gdev->dev.parent = gc->parent;
589 gdev->dev.of_node = gc->parent->of_node;
590 }
591
592 #ifdef CONFIG_OF_GPIO
593 /* If the gpiochip has an assigned OF node this takes precedence */
594 if (gc->of_node)
595 gdev->dev.of_node = gc->of_node;
596 else
597 gc->of_node = gdev->dev.of_node;
598 #endif
599
600 /*
601 * Assign fwnode depending on the result of the previous calls,
602 * if none of them succeed, assign it to the parent's one.
603 */
604 gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
605
606 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
607 if (gdev->id < 0) {
608 ret = gdev->id;
609 goto err_free_gdev;
610 }
611
612 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
613 if (ret)
614 goto err_free_ida;
615
616 device_initialize(&gdev->dev);
617 dev_set_drvdata(&gdev->dev, gdev);
618 if (gc->parent && gc->parent->driver)
619 gdev->owner = gc->parent->driver->owner;
620 else if (gc->owner)
621 /* TODO: remove chip->owner */
622 gdev->owner = gc->owner;
623 else
624 gdev->owner = THIS_MODULE;
625
626 gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
627 if (!gdev->descs) {
628 ret = -ENOMEM;
629 goto err_free_dev_name;
630 }
631
632 if (gc->ngpio == 0) {
633 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
634 ret = -EINVAL;
635 goto err_free_descs;
636 }
637
638 if (gc->ngpio > FASTPATH_NGPIO)
639 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
640 gc->ngpio, FASTPATH_NGPIO);
641
642 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
643 if (!gdev->label) {
644 ret = -ENOMEM;
645 goto err_free_descs;
646 }
647
648 gdev->ngpio = gc->ngpio;
649 gdev->data = data;
650
651 spin_lock_irqsave(&gpio_lock, flags);
652
653 /*
654 * TODO: this allocates a Linux GPIO number base in the global
655 * GPIO numberspace for this chip. In the long run we want to
656 * get *rid* of this numberspace and use only descriptors, but
657 * it may be a pipe dream. It will not happen before we get rid
658 * of the sysfs interface anyways.
659 */
660 if (base < 0) {
661 base = gpiochip_find_base(gc->ngpio);
662 if (base < 0) {
663 ret = base;
664 spin_unlock_irqrestore(&gpio_lock, flags);
665 goto err_free_label;
666 }
667 /*
668 * TODO: it should not be necessary to reflect the assigned
669 * base outside of the GPIO subsystem. Go over drivers and
670 * see if anyone makes use of this, else drop this and assign
671 * a poison instead.
672 */
673 gc->base = base;
674 }
675 gdev->base = base;
676
677 ret = gpiodev_add_to_list(gdev);
678 if (ret) {
679 spin_unlock_irqrestore(&gpio_lock, flags);
680 goto err_free_label;
681 }
682
683 for (i = 0; i < gc->ngpio; i++)
684 gdev->descs[i].gdev = gdev;
685
686 spin_unlock_irqrestore(&gpio_lock, flags);
687
688 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
689
690 #ifdef CONFIG_PINCTRL
691 INIT_LIST_HEAD(&gdev->pin_ranges);
692 #endif
693
694 if (gc->names)
695 ret = gpiochip_set_desc_names(gc);
696 else
697 ret = devprop_gpiochip_set_names(gc);
698 if (ret)
699 goto err_remove_from_list;
700
701 ret = gpiochip_alloc_valid_mask(gc);
702 if (ret)
703 goto err_remove_from_list;
704
705 ret = of_gpiochip_add(gc);
706 if (ret)
707 goto err_free_gpiochip_mask;
708
709 ret = gpiochip_init_valid_mask(gc);
710 if (ret)
711 goto err_remove_of_chip;
712
713 for (i = 0; i < gc->ngpio; i++) {
714 struct gpio_desc *desc = &gdev->descs[i];
715
716 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
717 assign_bit(FLAG_IS_OUT,
718 &desc->flags, !gc->get_direction(gc, i));
719 } else {
720 assign_bit(FLAG_IS_OUT,
721 &desc->flags, !gc->direction_input);
722 }
723 }
724
725 ret = gpiochip_add_pin_ranges(gc);
726 if (ret)
727 goto err_remove_of_chip;
728
729 acpi_gpiochip_add(gc);
730
731 machine_gpiochip_add(gc);
732
733 ret = gpiochip_irqchip_init_valid_mask(gc);
734 if (ret)
735 goto err_remove_acpi_chip;
736
737 ret = gpiochip_irqchip_init_hw(gc);
738 if (ret)
739 goto err_remove_acpi_chip;
740
741 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
742 if (ret)
743 goto err_remove_irqchip_mask;
744
745 /*
746 * By first adding the chardev, and then adding the device,
747 * we get a device node entry in sysfs under
748 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
749 * coldplug of device nodes and other udev business.
750 * We can do this only if gpiolib has been initialized.
751 * Otherwise, defer until later.
752 */
753 if (gpiolib_initialized) {
754 ret = gpiochip_setup_dev(gdev);
755 if (ret)
756 goto err_remove_irqchip;
757 }
758 return 0;
759
760 err_remove_irqchip:
761 gpiochip_irqchip_remove(gc);
762 err_remove_irqchip_mask:
763 gpiochip_irqchip_free_valid_mask(gc);
764 err_remove_acpi_chip:
765 acpi_gpiochip_remove(gc);
766 err_remove_of_chip:
767 gpiochip_free_hogs(gc);
768 of_gpiochip_remove(gc);
769 err_free_gpiochip_mask:
770 gpiochip_remove_pin_ranges(gc);
771 gpiochip_free_valid_mask(gc);
772 err_remove_from_list:
773 spin_lock_irqsave(&gpio_lock, flags);
774 list_del(&gdev->list);
775 spin_unlock_irqrestore(&gpio_lock, flags);
776 err_free_label:
777 kfree_const(gdev->label);
778 err_free_descs:
779 kfree(gdev->descs);
780 err_free_dev_name:
781 kfree(dev_name(&gdev->dev));
782 err_free_ida:
783 ida_free(&gpio_ida, gdev->id);
784 err_free_gdev:
785 /* failures here can mean systems won't boot... */
786 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
787 gdev->base, gdev->base + gdev->ngpio - 1,
788 gc->label ? : "generic", ret);
789 kfree(gdev);
790 return ret;
791 }
792 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
793
794 /**
795 * gpiochip_get_data() - get per-subdriver data for the chip
796 * @gc: GPIO chip
797 *
798 * Returns:
799 * The per-subdriver data for the chip.
800 */
gpiochip_get_data(struct gpio_chip * gc)801 void *gpiochip_get_data(struct gpio_chip *gc)
802 {
803 return gc->gpiodev->data;
804 }
805 EXPORT_SYMBOL_GPL(gpiochip_get_data);
806
807 /**
808 * gpiochip_remove() - unregister a gpio_chip
809 * @gc: the chip to unregister
810 *
811 * A gpio_chip with any GPIOs still requested may not be removed.
812 */
gpiochip_remove(struct gpio_chip * gc)813 void gpiochip_remove(struct gpio_chip *gc)
814 {
815 struct gpio_device *gdev = gc->gpiodev;
816 unsigned long flags;
817 unsigned int i;
818
819 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
820 gpiochip_sysfs_unregister(gdev);
821 gpiochip_free_hogs(gc);
822 /* Numb the device, cancelling all outstanding operations */
823 gdev->chip = NULL;
824 gpiochip_irqchip_remove(gc);
825 acpi_gpiochip_remove(gc);
826 of_gpiochip_remove(gc);
827 gpiochip_remove_pin_ranges(gc);
828 gpiochip_free_valid_mask(gc);
829 /*
830 * We accept no more calls into the driver from this point, so
831 * NULL the driver data pointer
832 */
833 gdev->data = NULL;
834
835 spin_lock_irqsave(&gpio_lock, flags);
836 for (i = 0; i < gdev->ngpio; i++) {
837 if (gpiochip_is_requested(gc, i))
838 break;
839 }
840 spin_unlock_irqrestore(&gpio_lock, flags);
841
842 if (i != gdev->ngpio)
843 dev_crit(&gdev->dev,
844 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
845
846 /*
847 * The gpiochip side puts its use of the device to rest here:
848 * if there are no userspace clients, the chardev and device will
849 * be removed, else it will be dangling until the last user is
850 * gone.
851 */
852 gcdev_unregister(gdev);
853 put_device(&gdev->dev);
854 }
855 EXPORT_SYMBOL_GPL(gpiochip_remove);
856
857 /**
858 * gpiochip_find() - iterator for locating a specific gpio_chip
859 * @data: data to pass to match function
860 * @match: Callback function to check gpio_chip
861 *
862 * Similar to bus_find_device. It returns a reference to a gpio_chip as
863 * determined by a user supplied @match callback. The callback should return
864 * 0 if the device doesn't match and non-zero if it does. If the callback is
865 * non-zero, this function will return to the caller and not iterate over any
866 * more gpio_chips.
867 */
gpiochip_find(void * data,int (* match)(struct gpio_chip * gc,void * data))868 struct gpio_chip *gpiochip_find(void *data,
869 int (*match)(struct gpio_chip *gc,
870 void *data))
871 {
872 struct gpio_device *gdev;
873 struct gpio_chip *gc = NULL;
874 unsigned long flags;
875
876 spin_lock_irqsave(&gpio_lock, flags);
877 list_for_each_entry(gdev, &gpio_devices, list)
878 if (gdev->chip && match(gdev->chip, data)) {
879 gc = gdev->chip;
880 break;
881 }
882
883 spin_unlock_irqrestore(&gpio_lock, flags);
884
885 return gc;
886 }
887 EXPORT_SYMBOL_GPL(gpiochip_find);
888
gpiochip_match_name(struct gpio_chip * gc,void * data)889 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
890 {
891 const char *name = data;
892
893 return !strcmp(gc->label, name);
894 }
895
find_chip_by_name(const char * name)896 static struct gpio_chip *find_chip_by_name(const char *name)
897 {
898 return gpiochip_find((void *)name, gpiochip_match_name);
899 }
900
901 #ifdef CONFIG_GPIOLIB_IRQCHIP
902
903 /*
904 * The following is irqchip helper code for gpiochips.
905 */
906
gpiochip_irqchip_init_hw(struct gpio_chip * gc)907 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
908 {
909 struct gpio_irq_chip *girq = &gc->irq;
910
911 if (!girq->init_hw)
912 return 0;
913
914 return girq->init_hw(gc);
915 }
916
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)917 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
918 {
919 struct gpio_irq_chip *girq = &gc->irq;
920
921 if (!girq->init_valid_mask)
922 return 0;
923
924 girq->valid_mask = gpiochip_allocate_mask(gc);
925 if (!girq->valid_mask)
926 return -ENOMEM;
927
928 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
929
930 return 0;
931 }
932
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)933 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
934 {
935 bitmap_free(gc->irq.valid_mask);
936 gc->irq.valid_mask = NULL;
937 }
938
gpiochip_irqchip_irq_valid(const struct gpio_chip * gc,unsigned int offset)939 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
940 unsigned int offset)
941 {
942 if (!gpiochip_line_is_valid(gc, offset))
943 return false;
944 /* No mask means all valid */
945 if (likely(!gc->irq.valid_mask))
946 return true;
947 return test_bit(offset, gc->irq.valid_mask);
948 }
949 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
950
951 /**
952 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
953 * @gc: the gpiochip to set the irqchip chain to
954 * @parent_irq: the irq number corresponding to the parent IRQ for this
955 * cascaded irqchip
956 * @parent_handler: the parent interrupt handler for the accumulated IRQ
957 * coming out of the gpiochip. If the interrupt is nested rather than
958 * cascaded, pass NULL in this handler argument
959 */
gpiochip_set_cascaded_irqchip(struct gpio_chip * gc,unsigned int parent_irq,irq_flow_handler_t parent_handler)960 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gc,
961 unsigned int parent_irq,
962 irq_flow_handler_t parent_handler)
963 {
964 struct gpio_irq_chip *girq = &gc->irq;
965 struct device *dev = &gc->gpiodev->dev;
966
967 if (!girq->domain) {
968 chip_err(gc, "called %s before setting up irqchip\n",
969 __func__);
970 return;
971 }
972
973 if (parent_handler) {
974 if (gc->can_sleep) {
975 chip_err(gc,
976 "you cannot have chained interrupts on a chip that may sleep\n");
977 return;
978 }
979 girq->parents = devm_kcalloc(dev, 1,
980 sizeof(*girq->parents),
981 GFP_KERNEL);
982 if (!girq->parents) {
983 chip_err(gc, "out of memory allocating parent IRQ\n");
984 return;
985 }
986 girq->parents[0] = parent_irq;
987 girq->num_parents = 1;
988 /*
989 * The parent irqchip is already using the chip_data for this
990 * irqchip, so our callbacks simply use the handler_data.
991 */
992 irq_set_chained_handler_and_data(parent_irq, parent_handler,
993 gc);
994 }
995 }
996
997 /**
998 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
999 * @gc: the gpiochip to set the irqchip nested handler to
1000 * @irqchip: the irqchip to nest to the gpiochip
1001 * @parent_irq: the irq number corresponding to the parent IRQ for this
1002 * nested irqchip
1003 */
gpiochip_set_nested_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip,unsigned int parent_irq)1004 void gpiochip_set_nested_irqchip(struct gpio_chip *gc,
1005 struct irq_chip *irqchip,
1006 unsigned int parent_irq)
1007 {
1008 gpiochip_set_cascaded_irqchip(gc, parent_irq, NULL);
1009 }
1010 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1011
1012 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1013
1014 /**
1015 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1016 * to a gpiochip
1017 * @gc: the gpiochip to set the irqchip hierarchical handler to
1018 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1019 * will then percolate up to the parent
1020 */
gpiochip_set_hierarchical_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip)1021 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1022 struct irq_chip *irqchip)
1023 {
1024 /* DT will deal with mapping each IRQ as we go along */
1025 if (is_of_node(gc->irq.fwnode))
1026 return;
1027
1028 /*
1029 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1030 * irqs upfront instead of dynamically since we don't have the
1031 * dynamic type of allocation that hardware description languages
1032 * provide. Once all GPIO drivers using board files are gone from
1033 * the kernel we can delete this code, but for a transitional period
1034 * it is necessary to keep this around.
1035 */
1036 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1037 int i;
1038 int ret;
1039
1040 for (i = 0; i < gc->ngpio; i++) {
1041 struct irq_fwspec fwspec;
1042 unsigned int parent_hwirq;
1043 unsigned int parent_type;
1044 struct gpio_irq_chip *girq = &gc->irq;
1045
1046 /*
1047 * We call the child to parent translation function
1048 * only to check if the child IRQ is valid or not.
1049 * Just pick the rising edge type here as that is what
1050 * we likely need to support.
1051 */
1052 ret = girq->child_to_parent_hwirq(gc, i,
1053 IRQ_TYPE_EDGE_RISING,
1054 &parent_hwirq,
1055 &parent_type);
1056 if (ret) {
1057 chip_err(gc, "skip set-up on hwirq %d\n",
1058 i);
1059 continue;
1060 }
1061
1062 fwspec.fwnode = gc->irq.fwnode;
1063 /* This is the hwirq for the GPIO line side of things */
1064 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1065 /* Just pick something */
1066 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1067 fwspec.param_count = 2;
1068 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1069 /* just pick something */
1070 -1,
1071 1,
1072 NUMA_NO_NODE,
1073 &fwspec,
1074 false,
1075 NULL);
1076 if (ret < 0) {
1077 chip_err(gc,
1078 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1079 i, parent_hwirq,
1080 ret);
1081 }
1082 }
1083 }
1084
1085 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1086
1087 return;
1088 }
1089
gpiochip_hierarchy_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1090 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1091 struct irq_fwspec *fwspec,
1092 unsigned long *hwirq,
1093 unsigned int *type)
1094 {
1095 /* We support standard DT translation */
1096 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1097 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1098 }
1099
1100 /* This is for board files and others not using DT */
1101 if (is_fwnode_irqchip(fwspec->fwnode)) {
1102 int ret;
1103
1104 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1105 if (ret)
1106 return ret;
1107 WARN_ON(*type == IRQ_TYPE_NONE);
1108 return 0;
1109 }
1110 return -EINVAL;
1111 }
1112
gpiochip_hierarchy_irq_domain_alloc(struct irq_domain * d,unsigned int irq,unsigned int nr_irqs,void * data)1113 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1114 unsigned int irq,
1115 unsigned int nr_irqs,
1116 void *data)
1117 {
1118 struct gpio_chip *gc = d->host_data;
1119 irq_hw_number_t hwirq;
1120 unsigned int type = IRQ_TYPE_NONE;
1121 struct irq_fwspec *fwspec = data;
1122 void *parent_arg;
1123 unsigned int parent_hwirq;
1124 unsigned int parent_type;
1125 struct gpio_irq_chip *girq = &gc->irq;
1126 int ret;
1127
1128 /*
1129 * The nr_irqs parameter is always one except for PCI multi-MSI
1130 * so this should not happen.
1131 */
1132 WARN_ON(nr_irqs != 1);
1133
1134 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1135 if (ret)
1136 return ret;
1137
1138 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1139
1140 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1141 &parent_hwirq, &parent_type);
1142 if (ret) {
1143 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1144 return ret;
1145 }
1146 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1147
1148 /*
1149 * We set handle_bad_irq because the .set_type() should
1150 * always be invoked and set the right type of handler.
1151 */
1152 irq_domain_set_info(d,
1153 irq,
1154 hwirq,
1155 gc->irq.chip,
1156 gc,
1157 girq->handler,
1158 NULL, NULL);
1159 irq_set_probe(irq);
1160
1161 /* This parent only handles asserted level IRQs */
1162 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1163 if (!parent_arg)
1164 return -ENOMEM;
1165
1166 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1167 irq, parent_hwirq);
1168 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1169 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1170 /*
1171 * If the parent irqdomain is msi, the interrupts have already
1172 * been allocated, so the EEXIST is good.
1173 */
1174 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1175 ret = 0;
1176 if (ret)
1177 chip_err(gc,
1178 "failed to allocate parent hwirq %d for hwirq %lu\n",
1179 parent_hwirq, hwirq);
1180
1181 kfree(parent_arg);
1182 return ret;
1183 }
1184
gpiochip_child_offset_to_irq_noop(struct gpio_chip * gc,unsigned int offset)1185 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1186 unsigned int offset)
1187 {
1188 return offset;
1189 }
1190
gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops * ops)1191 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1192 {
1193 ops->activate = gpiochip_irq_domain_activate;
1194 ops->deactivate = gpiochip_irq_domain_deactivate;
1195 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1196 ops->free = irq_domain_free_irqs_common;
1197
1198 /*
1199 * We only allow overriding the translate() function for
1200 * hierarchical chips, and this should only be done if the user
1201 * really need something other than 1:1 translation.
1202 */
1203 if (!ops->translate)
1204 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1205 }
1206
gpiochip_hierarchy_add_domain(struct gpio_chip * gc)1207 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1208 {
1209 if (!gc->irq.child_to_parent_hwirq ||
1210 !gc->irq.fwnode) {
1211 chip_err(gc, "missing irqdomain vital data\n");
1212 return -EINVAL;
1213 }
1214
1215 if (!gc->irq.child_offset_to_irq)
1216 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1217
1218 if (!gc->irq.populate_parent_alloc_arg)
1219 gc->irq.populate_parent_alloc_arg =
1220 gpiochip_populate_parent_fwspec_twocell;
1221
1222 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1223
1224 gc->irq.domain = irq_domain_create_hierarchy(
1225 gc->irq.parent_domain,
1226 0,
1227 gc->ngpio,
1228 gc->irq.fwnode,
1229 &gc->irq.child_irq_domain_ops,
1230 gc);
1231
1232 if (!gc->irq.domain)
1233 return -ENOMEM;
1234
1235 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1236
1237 return 0;
1238 }
1239
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1240 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1241 {
1242 return !!gc->irq.parent_domain;
1243 }
1244
gpiochip_populate_parent_fwspec_twocell(struct gpio_chip * gc,unsigned int parent_hwirq,unsigned int parent_type)1245 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1246 unsigned int parent_hwirq,
1247 unsigned int parent_type)
1248 {
1249 struct irq_fwspec *fwspec;
1250
1251 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1252 if (!fwspec)
1253 return NULL;
1254
1255 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1256 fwspec->param_count = 2;
1257 fwspec->param[0] = parent_hwirq;
1258 fwspec->param[1] = parent_type;
1259
1260 return fwspec;
1261 }
1262 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1263
gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip * gc,unsigned int parent_hwirq,unsigned int parent_type)1264 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1265 unsigned int parent_hwirq,
1266 unsigned int parent_type)
1267 {
1268 struct irq_fwspec *fwspec;
1269
1270 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1271 if (!fwspec)
1272 return NULL;
1273
1274 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1275 fwspec->param_count = 4;
1276 fwspec->param[0] = 0;
1277 fwspec->param[1] = parent_hwirq;
1278 fwspec->param[2] = 0;
1279 fwspec->param[3] = parent_type;
1280
1281 return fwspec;
1282 }
1283 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1284
1285 #else
1286
gpiochip_hierarchy_add_domain(struct gpio_chip * gc)1287 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1288 {
1289 return -EINVAL;
1290 }
1291
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1292 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1293 {
1294 return false;
1295 }
1296
1297 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1298
1299 /**
1300 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1301 * @d: the irqdomain used by this irqchip
1302 * @irq: the global irq number used by this GPIO irqchip irq
1303 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1304 *
1305 * This function will set up the mapping for a certain IRQ line on a
1306 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1307 * stored inside the gpiochip.
1308 */
gpiochip_irq_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)1309 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1310 irq_hw_number_t hwirq)
1311 {
1312 struct gpio_chip *gc = d->host_data;
1313 int ret = 0;
1314
1315 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1316 return -ENXIO;
1317
1318 irq_set_chip_data(irq, gc);
1319 /*
1320 * This lock class tells lockdep that GPIO irqs are in a different
1321 * category than their parents, so it won't report false recursion.
1322 */
1323 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1324 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1325 /* Chips that use nested thread handlers have them marked */
1326 if (gc->irq.threaded)
1327 irq_set_nested_thread(irq, 1);
1328 irq_set_noprobe(irq);
1329
1330 if (gc->irq.num_parents == 1)
1331 ret = irq_set_parent(irq, gc->irq.parents[0]);
1332 else if (gc->irq.map)
1333 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1334
1335 if (ret < 0)
1336 return ret;
1337
1338 /*
1339 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1340 * is passed as default type.
1341 */
1342 if (gc->irq.default_type != IRQ_TYPE_NONE)
1343 irq_set_irq_type(irq, gc->irq.default_type);
1344
1345 return 0;
1346 }
1347 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1348
gpiochip_irq_unmap(struct irq_domain * d,unsigned int irq)1349 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1350 {
1351 struct gpio_chip *gc = d->host_data;
1352
1353 if (gc->irq.threaded)
1354 irq_set_nested_thread(irq, 0);
1355 irq_set_chip_and_handler(irq, NULL, NULL);
1356 irq_set_chip_data(irq, NULL);
1357 }
1358 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1359
1360 static const struct irq_domain_ops gpiochip_domain_ops = {
1361 .map = gpiochip_irq_map,
1362 .unmap = gpiochip_irq_unmap,
1363 /* Virtually all GPIO irqchips are twocell:ed */
1364 .xlate = irq_domain_xlate_twocell,
1365 };
1366
1367 /*
1368 * TODO: move these activate/deactivate in under the hierarchicial
1369 * irqchip implementation as static once SPMI and SSBI (all external
1370 * users) are phased over.
1371 */
1372 /**
1373 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1374 * @domain: The IRQ domain used by this IRQ chip
1375 * @data: Outermost irq_data associated with the IRQ
1376 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1377 *
1378 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1379 * used as the activate function for the &struct irq_domain_ops. The host_data
1380 * for the IRQ domain must be the &struct gpio_chip.
1381 */
gpiochip_irq_domain_activate(struct irq_domain * domain,struct irq_data * data,bool reserve)1382 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1383 struct irq_data *data, bool reserve)
1384 {
1385 struct gpio_chip *gc = domain->host_data;
1386
1387 return gpiochip_lock_as_irq(gc, data->hwirq);
1388 }
1389 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1390
1391 /**
1392 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1393 * @domain: The IRQ domain used by this IRQ chip
1394 * @data: Outermost irq_data associated with the IRQ
1395 *
1396 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1397 * be used as the deactivate function for the &struct irq_domain_ops. The
1398 * host_data for the IRQ domain must be the &struct gpio_chip.
1399 */
gpiochip_irq_domain_deactivate(struct irq_domain * domain,struct irq_data * data)1400 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1401 struct irq_data *data)
1402 {
1403 struct gpio_chip *gc = domain->host_data;
1404
1405 return gpiochip_unlock_as_irq(gc, data->hwirq);
1406 }
1407 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1408
gpiochip_to_irq(struct gpio_chip * gc,unsigned offset)1409 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned offset)
1410 {
1411 struct irq_domain *domain = gc->irq.domain;
1412
1413 #ifdef CONFIG_GPIOLIB_IRQCHIP
1414 /*
1415 * Avoid race condition with other code, which tries to lookup
1416 * an IRQ before the irqchip has been properly registered,
1417 * i.e. while gpiochip is still being brought up.
1418 */
1419 if (!gc->irq.initialized)
1420 return -EPROBE_DEFER;
1421 #endif
1422
1423 if (!gpiochip_irqchip_irq_valid(gc, offset))
1424 return -ENXIO;
1425
1426 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1427 if (irq_domain_is_hierarchy(domain)) {
1428 struct irq_fwspec spec;
1429
1430 spec.fwnode = domain->fwnode;
1431 spec.param_count = 2;
1432 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1433 spec.param[1] = IRQ_TYPE_NONE;
1434
1435 return irq_create_fwspec_mapping(&spec);
1436 }
1437 #endif
1438
1439 return irq_create_mapping(domain, offset);
1440 }
1441
gpiochip_irq_reqres(struct irq_data * d)1442 static int gpiochip_irq_reqres(struct irq_data *d)
1443 {
1444 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1445
1446 return gpiochip_reqres_irq(gc, d->hwirq);
1447 }
1448
gpiochip_irq_relres(struct irq_data * d)1449 static void gpiochip_irq_relres(struct irq_data *d)
1450 {
1451 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1452
1453 gpiochip_relres_irq(gc, d->hwirq);
1454 }
1455
gpiochip_irq_mask(struct irq_data * d)1456 static void gpiochip_irq_mask(struct irq_data *d)
1457 {
1458 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1459
1460 if (gc->irq.irq_mask)
1461 gc->irq.irq_mask(d);
1462 gpiochip_disable_irq(gc, d->hwirq);
1463 }
1464
gpiochip_irq_unmask(struct irq_data * d)1465 static void gpiochip_irq_unmask(struct irq_data *d)
1466 {
1467 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1468
1469 gpiochip_enable_irq(gc, d->hwirq);
1470 if (gc->irq.irq_unmask)
1471 gc->irq.irq_unmask(d);
1472 }
1473
gpiochip_irq_enable(struct irq_data * d)1474 static void gpiochip_irq_enable(struct irq_data *d)
1475 {
1476 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1477
1478 gpiochip_enable_irq(gc, d->hwirq);
1479 gc->irq.irq_enable(d);
1480 }
1481
gpiochip_irq_disable(struct irq_data * d)1482 static void gpiochip_irq_disable(struct irq_data *d)
1483 {
1484 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1485
1486 gc->irq.irq_disable(d);
1487 gpiochip_disable_irq(gc, d->hwirq);
1488 }
1489
gpiochip_set_irq_hooks(struct gpio_chip * gc)1490 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1491 {
1492 struct irq_chip *irqchip = gc->irq.chip;
1493
1494 if (!irqchip->irq_request_resources &&
1495 !irqchip->irq_release_resources) {
1496 irqchip->irq_request_resources = gpiochip_irq_reqres;
1497 irqchip->irq_release_resources = gpiochip_irq_relres;
1498 }
1499 if (WARN_ON(gc->irq.irq_enable))
1500 return;
1501 /* Check if the irqchip already has this hook... */
1502 if (irqchip->irq_enable == gpiochip_irq_enable ||
1503 irqchip->irq_mask == gpiochip_irq_mask) {
1504 /*
1505 * ...and if so, give a gentle warning that this is bad
1506 * practice.
1507 */
1508 chip_info(gc,
1509 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1510 return;
1511 }
1512
1513 if (irqchip->irq_disable) {
1514 gc->irq.irq_disable = irqchip->irq_disable;
1515 irqchip->irq_disable = gpiochip_irq_disable;
1516 } else {
1517 gc->irq.irq_mask = irqchip->irq_mask;
1518 irqchip->irq_mask = gpiochip_irq_mask;
1519 }
1520
1521 if (irqchip->irq_enable) {
1522 gc->irq.irq_enable = irqchip->irq_enable;
1523 irqchip->irq_enable = gpiochip_irq_enable;
1524 } else {
1525 gc->irq.irq_unmask = irqchip->irq_unmask;
1526 irqchip->irq_unmask = gpiochip_irq_unmask;
1527 }
1528 }
1529
1530 /**
1531 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1532 * @gc: the GPIO chip to add the IRQ chip to
1533 * @lock_key: lockdep class for IRQ lock
1534 * @request_key: lockdep class for IRQ request
1535 */
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)1536 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1537 struct lock_class_key *lock_key,
1538 struct lock_class_key *request_key)
1539 {
1540 struct irq_chip *irqchip = gc->irq.chip;
1541 const struct irq_domain_ops *ops = NULL;
1542 struct device_node *np;
1543 unsigned int type;
1544 unsigned int i;
1545
1546 if (!irqchip)
1547 return 0;
1548
1549 if (gc->irq.parent_handler && gc->can_sleep) {
1550 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1551 return -EINVAL;
1552 }
1553
1554 np = gc->gpiodev->dev.of_node;
1555 type = gc->irq.default_type;
1556
1557 /*
1558 * Specifying a default trigger is a terrible idea if DT or ACPI is
1559 * used to configure the interrupts, as you may end up with
1560 * conflicting triggers. Tell the user, and reset to NONE.
1561 */
1562 if (WARN(np && type != IRQ_TYPE_NONE,
1563 "%s: Ignoring %u default trigger\n", np->full_name, type))
1564 type = IRQ_TYPE_NONE;
1565
1566 if (has_acpi_companion(gc->parent) && type != IRQ_TYPE_NONE) {
1567 acpi_handle_warn(ACPI_HANDLE(gc->parent),
1568 "Ignoring %u default trigger\n", type);
1569 type = IRQ_TYPE_NONE;
1570 }
1571
1572 gc->to_irq = gpiochip_to_irq;
1573 gc->irq.default_type = type;
1574 gc->irq.lock_key = lock_key;
1575 gc->irq.request_key = request_key;
1576
1577 /* If a parent irqdomain is provided, let's build a hierarchy */
1578 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1579 int ret = gpiochip_hierarchy_add_domain(gc);
1580 if (ret)
1581 return ret;
1582 } else {
1583 /* Some drivers provide custom irqdomain ops */
1584 if (gc->irq.domain_ops)
1585 ops = gc->irq.domain_ops;
1586
1587 if (!ops)
1588 ops = &gpiochip_domain_ops;
1589 gc->irq.domain = irq_domain_add_simple(np,
1590 gc->ngpio,
1591 gc->irq.first,
1592 ops, gc);
1593 if (!gc->irq.domain)
1594 return -EINVAL;
1595 }
1596
1597 if (gc->irq.parent_handler) {
1598 void *data = gc->irq.parent_handler_data ?: gc;
1599
1600 for (i = 0; i < gc->irq.num_parents; i++) {
1601 /*
1602 * The parent IRQ chip is already using the chip_data
1603 * for this IRQ chip, so our callbacks simply use the
1604 * handler_data.
1605 */
1606 irq_set_chained_handler_and_data(gc->irq.parents[i],
1607 gc->irq.parent_handler,
1608 data);
1609 }
1610 }
1611
1612 gpiochip_set_irq_hooks(gc);
1613
1614 /*
1615 * Using barrier() here to prevent compiler from reordering
1616 * gc->irq.initialized before initialization of above
1617 * GPIO chip irq members.
1618 */
1619 barrier();
1620
1621 gc->irq.initialized = true;
1622
1623 acpi_gpiochip_request_interrupts(gc);
1624
1625 return 0;
1626 }
1627
1628 /**
1629 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1630 * @gc: the gpiochip to remove the irqchip from
1631 *
1632 * This is called only from gpiochip_remove()
1633 */
gpiochip_irqchip_remove(struct gpio_chip * gc)1634 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1635 {
1636 struct irq_chip *irqchip = gc->irq.chip;
1637 unsigned int offset;
1638
1639 acpi_gpiochip_free_interrupts(gc);
1640
1641 if (irqchip && gc->irq.parent_handler) {
1642 struct gpio_irq_chip *irq = &gc->irq;
1643 unsigned int i;
1644
1645 for (i = 0; i < irq->num_parents; i++)
1646 irq_set_chained_handler_and_data(irq->parents[i],
1647 NULL, NULL);
1648 }
1649
1650 /* Remove all IRQ mappings and delete the domain */
1651 if (gc->irq.domain) {
1652 unsigned int irq;
1653
1654 for (offset = 0; offset < gc->ngpio; offset++) {
1655 if (!gpiochip_irqchip_irq_valid(gc, offset))
1656 continue;
1657
1658 irq = irq_find_mapping(gc->irq.domain, offset);
1659 irq_dispose_mapping(irq);
1660 }
1661
1662 irq_domain_remove(gc->irq.domain);
1663 }
1664
1665 if (irqchip) {
1666 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1667 irqchip->irq_request_resources = NULL;
1668 irqchip->irq_release_resources = NULL;
1669 }
1670 if (irqchip->irq_enable == gpiochip_irq_enable) {
1671 irqchip->irq_enable = gc->irq.irq_enable;
1672 irqchip->irq_disable = gc->irq.irq_disable;
1673 }
1674 }
1675 gc->irq.irq_enable = NULL;
1676 gc->irq.irq_disable = NULL;
1677 gc->irq.chip = NULL;
1678
1679 gpiochip_irqchip_free_valid_mask(gc);
1680 }
1681
1682 /**
1683 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1684 * @gc: the gpiochip to add the irqchip to
1685 * @irqchip: the irqchip to add to the gpiochip
1686 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1687 * allocate gpiochip irqs from
1688 * @handler: the irq handler to use (often a predefined irq core function)
1689 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1690 * to have the core avoid setting up any default type in the hardware.
1691 * @threaded: whether this irqchip uses a nested thread handler
1692 * @lock_key: lockdep class for IRQ lock
1693 * @request_key: lockdep class for IRQ request
1694 *
1695 * This function closely associates a certain irqchip with a certain
1696 * gpiochip, providing an irq domain to translate the local IRQs to
1697 * global irqs in the gpiolib core, and making sure that the gpiochip
1698 * is passed as chip data to all related functions. Driver callbacks
1699 * need to use gpiochip_get_data() to get their local state containers back
1700 * from the gpiochip passed as chip data. An irqdomain will be stored
1701 * in the gpiochip that shall be used by the driver to handle IRQ number
1702 * translation. The gpiochip will need to be initialized and registered
1703 * before calling this function.
1704 *
1705 * This function will handle two cell:ed simple IRQs and assumes all
1706 * the pins on the gpiochip can generate a unique IRQ. Everything else
1707 * need to be open coded.
1708 */
gpiochip_irqchip_add_key(struct gpio_chip * gc,struct irq_chip * irqchip,unsigned int first_irq,irq_flow_handler_t handler,unsigned int type,bool threaded,struct lock_class_key * lock_key,struct lock_class_key * request_key)1709 int gpiochip_irqchip_add_key(struct gpio_chip *gc,
1710 struct irq_chip *irqchip,
1711 unsigned int first_irq,
1712 irq_flow_handler_t handler,
1713 unsigned int type,
1714 bool threaded,
1715 struct lock_class_key *lock_key,
1716 struct lock_class_key *request_key)
1717 {
1718 struct device_node *of_node;
1719
1720 if (!gc || !irqchip)
1721 return -EINVAL;
1722
1723 if (!gc->parent) {
1724 chip_err(gc, "missing gpiochip .dev parent pointer\n");
1725 return -EINVAL;
1726 }
1727 gc->irq.threaded = threaded;
1728 of_node = gc->parent->of_node;
1729 #ifdef CONFIG_OF_GPIO
1730 /*
1731 * If the gpiochip has an assigned OF node this takes precedence
1732 * FIXME: get rid of this and use gc->parent->of_node
1733 * everywhere
1734 */
1735 if (gc->of_node)
1736 of_node = gc->of_node;
1737 #endif
1738 /*
1739 * Specifying a default trigger is a terrible idea if DT or ACPI is
1740 * used to configure the interrupts, as you may end-up with
1741 * conflicting triggers. Tell the user, and reset to NONE.
1742 */
1743 if (WARN(of_node && type != IRQ_TYPE_NONE,
1744 "%pOF: Ignoring %d default trigger\n", of_node, type))
1745 type = IRQ_TYPE_NONE;
1746 if (has_acpi_companion(gc->parent) && type != IRQ_TYPE_NONE) {
1747 acpi_handle_warn(ACPI_HANDLE(gc->parent),
1748 "Ignoring %d default trigger\n", type);
1749 type = IRQ_TYPE_NONE;
1750 }
1751
1752 gc->irq.chip = irqchip;
1753 gc->irq.handler = handler;
1754 gc->irq.default_type = type;
1755 gc->to_irq = gpiochip_to_irq;
1756 gc->irq.lock_key = lock_key;
1757 gc->irq.request_key = request_key;
1758 gc->irq.domain = irq_domain_add_simple(of_node,
1759 gc->ngpio, first_irq,
1760 &gpiochip_domain_ops, gc);
1761 if (!gc->irq.domain) {
1762 gc->irq.chip = NULL;
1763 return -EINVAL;
1764 }
1765
1766 gpiochip_set_irq_hooks(gc);
1767
1768 acpi_gpiochip_request_interrupts(gc);
1769
1770 return 0;
1771 }
1772 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
1773
1774 /**
1775 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1776 * @gc: the gpiochip to add the irqchip to
1777 * @domain: the irqdomain to add to the gpiochip
1778 *
1779 * This function adds an IRQ domain to the gpiochip.
1780 */
gpiochip_irqchip_add_domain(struct gpio_chip * gc,struct irq_domain * domain)1781 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1782 struct irq_domain *domain)
1783 {
1784 if (!domain)
1785 return -EINVAL;
1786
1787 gc->to_irq = gpiochip_to_irq;
1788 gc->irq.domain = domain;
1789
1790 return 0;
1791 }
1792 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1793
1794 #else /* CONFIG_GPIOLIB_IRQCHIP */
1795
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)1796 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1797 struct lock_class_key *lock_key,
1798 struct lock_class_key *request_key)
1799 {
1800 return 0;
1801 }
gpiochip_irqchip_remove(struct gpio_chip * gc)1802 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1803
gpiochip_irqchip_init_hw(struct gpio_chip * gc)1804 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1805 {
1806 return 0;
1807 }
1808
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)1809 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1810 {
1811 return 0;
1812 }
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)1813 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1814 { }
1815
1816 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1817
1818 /**
1819 * gpiochip_generic_request() - request the gpio function for a pin
1820 * @gc: the gpiochip owning the GPIO
1821 * @offset: the offset of the GPIO to request for GPIO function
1822 */
gpiochip_generic_request(struct gpio_chip * gc,unsigned offset)1823 int gpiochip_generic_request(struct gpio_chip *gc, unsigned offset)
1824 {
1825 #ifdef CONFIG_PINCTRL
1826 if (list_empty(&gc->gpiodev->pin_ranges))
1827 return 0;
1828 #endif
1829
1830 return pinctrl_gpio_request(gc->gpiodev->base + offset);
1831 }
1832 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1833
1834 /**
1835 * gpiochip_generic_free() - free the gpio function from a pin
1836 * @gc: the gpiochip to request the gpio function for
1837 * @offset: the offset of the GPIO to free from GPIO function
1838 */
gpiochip_generic_free(struct gpio_chip * gc,unsigned offset)1839 void gpiochip_generic_free(struct gpio_chip *gc, unsigned offset)
1840 {
1841 #ifdef CONFIG_PINCTRL
1842 if (list_empty(&gc->gpiodev->pin_ranges))
1843 return;
1844 #endif
1845
1846 pinctrl_gpio_free(gc->gpiodev->base + offset);
1847 }
1848 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1849
1850 /**
1851 * gpiochip_generic_config() - apply configuration for a pin
1852 * @gc: the gpiochip owning the GPIO
1853 * @offset: the offset of the GPIO to apply the configuration
1854 * @config: the configuration to be applied
1855 */
gpiochip_generic_config(struct gpio_chip * gc,unsigned offset,unsigned long config)1856 int gpiochip_generic_config(struct gpio_chip *gc, unsigned offset,
1857 unsigned long config)
1858 {
1859 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1860 }
1861 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1862
1863 #ifdef CONFIG_PINCTRL
1864
1865 /**
1866 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1867 * @gc: the gpiochip to add the range for
1868 * @pctldev: the pin controller to map to
1869 * @gpio_offset: the start offset in the current gpio_chip number space
1870 * @pin_group: name of the pin group inside the pin controller
1871 *
1872 * Calling this function directly from a DeviceTree-supported
1873 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1874 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1875 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1876 */
gpiochip_add_pingroup_range(struct gpio_chip * gc,struct pinctrl_dev * pctldev,unsigned int gpio_offset,const char * pin_group)1877 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1878 struct pinctrl_dev *pctldev,
1879 unsigned int gpio_offset, const char *pin_group)
1880 {
1881 struct gpio_pin_range *pin_range;
1882 struct gpio_device *gdev = gc->gpiodev;
1883 int ret;
1884
1885 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1886 if (!pin_range) {
1887 chip_err(gc, "failed to allocate pin ranges\n");
1888 return -ENOMEM;
1889 }
1890
1891 /* Use local offset as range ID */
1892 pin_range->range.id = gpio_offset;
1893 pin_range->range.gc = gc;
1894 pin_range->range.name = gc->label;
1895 pin_range->range.base = gdev->base + gpio_offset;
1896 pin_range->pctldev = pctldev;
1897
1898 ret = pinctrl_get_group_pins(pctldev, pin_group,
1899 &pin_range->range.pins,
1900 &pin_range->range.npins);
1901 if (ret < 0) {
1902 kfree(pin_range);
1903 return ret;
1904 }
1905
1906 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1907
1908 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1909 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1910 pinctrl_dev_get_devname(pctldev), pin_group);
1911
1912 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1913
1914 return 0;
1915 }
1916 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1917
1918 /**
1919 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1920 * @gc: the gpiochip to add the range for
1921 * @pinctl_name: the dev_name() of the pin controller to map to
1922 * @gpio_offset: the start offset in the current gpio_chip number space
1923 * @pin_offset: the start offset in the pin controller number space
1924 * @npins: the number of pins from the offset of each pin space (GPIO and
1925 * pin controller) to accumulate in this range
1926 *
1927 * Returns:
1928 * 0 on success, or a negative error-code on failure.
1929 *
1930 * Calling this function directly from a DeviceTree-supported
1931 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1932 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1933 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1934 */
gpiochip_add_pin_range(struct gpio_chip * gc,const char * pinctl_name,unsigned int gpio_offset,unsigned int pin_offset,unsigned int npins)1935 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1936 unsigned int gpio_offset, unsigned int pin_offset,
1937 unsigned int npins)
1938 {
1939 struct gpio_pin_range *pin_range;
1940 struct gpio_device *gdev = gc->gpiodev;
1941 int ret;
1942
1943 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1944 if (!pin_range) {
1945 chip_err(gc, "failed to allocate pin ranges\n");
1946 return -ENOMEM;
1947 }
1948
1949 /* Use local offset as range ID */
1950 pin_range->range.id = gpio_offset;
1951 pin_range->range.gc = gc;
1952 pin_range->range.name = gc->label;
1953 pin_range->range.base = gdev->base + gpio_offset;
1954 pin_range->range.pin_base = pin_offset;
1955 pin_range->range.npins = npins;
1956 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1957 &pin_range->range);
1958 if (IS_ERR(pin_range->pctldev)) {
1959 ret = PTR_ERR(pin_range->pctldev);
1960 chip_err(gc, "could not create pin range\n");
1961 kfree(pin_range);
1962 return ret;
1963 }
1964 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1965 gpio_offset, gpio_offset + npins - 1,
1966 pinctl_name,
1967 pin_offset, pin_offset + npins - 1);
1968
1969 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1970
1971 return 0;
1972 }
1973 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1974
1975 /**
1976 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1977 * @gc: the chip to remove all the mappings for
1978 */
gpiochip_remove_pin_ranges(struct gpio_chip * gc)1979 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1980 {
1981 struct gpio_pin_range *pin_range, *tmp;
1982 struct gpio_device *gdev = gc->gpiodev;
1983
1984 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1985 list_del(&pin_range->node);
1986 pinctrl_remove_gpio_range(pin_range->pctldev,
1987 &pin_range->range);
1988 kfree(pin_range);
1989 }
1990 }
1991 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1992
1993 #endif /* CONFIG_PINCTRL */
1994
1995 /* These "optional" allocation calls help prevent drivers from stomping
1996 * on each other, and help provide better diagnostics in debugfs.
1997 * They're called even less than the "set direction" calls.
1998 */
gpiod_request_commit(struct gpio_desc * desc,const char * label)1999 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2000 {
2001 struct gpio_chip *gc = desc->gdev->chip;
2002 int ret;
2003 unsigned long flags;
2004 unsigned offset;
2005
2006 if (label) {
2007 label = kstrdup_const(label, GFP_KERNEL);
2008 if (!label)
2009 return -ENOMEM;
2010 }
2011
2012 spin_lock_irqsave(&gpio_lock, flags);
2013
2014 /* NOTE: gpio_request() can be called in early boot,
2015 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2016 */
2017
2018 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2019 desc_set_label(desc, label ? : "?");
2020 ret = 0;
2021 } else {
2022 kfree_const(label);
2023 ret = -EBUSY;
2024 goto done;
2025 }
2026
2027 if (gc->request) {
2028 /* gc->request may sleep */
2029 spin_unlock_irqrestore(&gpio_lock, flags);
2030 offset = gpio_chip_hwgpio(desc);
2031 if (gpiochip_line_is_valid(gc, offset))
2032 ret = gc->request(gc, offset);
2033 else
2034 ret = -EINVAL;
2035 spin_lock_irqsave(&gpio_lock, flags);
2036
2037 if (ret < 0) {
2038 desc_set_label(desc, NULL);
2039 kfree_const(label);
2040 clear_bit(FLAG_REQUESTED, &desc->flags);
2041 goto done;
2042 }
2043 }
2044 if (gc->get_direction) {
2045 /* gc->get_direction may sleep */
2046 spin_unlock_irqrestore(&gpio_lock, flags);
2047 gpiod_get_direction(desc);
2048 spin_lock_irqsave(&gpio_lock, flags);
2049 }
2050 done:
2051 spin_unlock_irqrestore(&gpio_lock, flags);
2052 return ret;
2053 }
2054
2055 /*
2056 * This descriptor validation needs to be inserted verbatim into each
2057 * function taking a descriptor, so we need to use a preprocessor
2058 * macro to avoid endless duplication. If the desc is NULL it is an
2059 * optional GPIO and calls should just bail out.
2060 */
validate_desc(const struct gpio_desc * desc,const char * func)2061 static int validate_desc(const struct gpio_desc *desc, const char *func)
2062 {
2063 if (!desc)
2064 return 0;
2065 if (IS_ERR(desc)) {
2066 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2067 return PTR_ERR(desc);
2068 }
2069 if (!desc->gdev) {
2070 pr_warn("%s: invalid GPIO (no device)\n", func);
2071 return -EINVAL;
2072 }
2073 if (!desc->gdev->chip) {
2074 dev_warn(&desc->gdev->dev,
2075 "%s: backing chip is gone\n", func);
2076 return 0;
2077 }
2078 return 1;
2079 }
2080
2081 #define VALIDATE_DESC(desc) do { \
2082 int __valid = validate_desc(desc, __func__); \
2083 if (__valid <= 0) \
2084 return __valid; \
2085 } while (0)
2086
2087 #define VALIDATE_DESC_VOID(desc) do { \
2088 int __valid = validate_desc(desc, __func__); \
2089 if (__valid <= 0) \
2090 return; \
2091 } while (0)
2092
gpiod_request(struct gpio_desc * desc,const char * label)2093 int gpiod_request(struct gpio_desc *desc, const char *label)
2094 {
2095 int ret = -EPROBE_DEFER;
2096 struct gpio_device *gdev;
2097
2098 VALIDATE_DESC(desc);
2099 gdev = desc->gdev;
2100
2101 if (try_module_get(gdev->owner)) {
2102 ret = gpiod_request_commit(desc, label);
2103 if (ret < 0)
2104 module_put(gdev->owner);
2105 else
2106 get_device(&gdev->dev);
2107 }
2108
2109 if (ret)
2110 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2111
2112 return ret;
2113 }
2114
gpiod_free_commit(struct gpio_desc * desc)2115 static bool gpiod_free_commit(struct gpio_desc *desc)
2116 {
2117 bool ret = false;
2118 unsigned long flags;
2119 struct gpio_chip *gc;
2120
2121 might_sleep();
2122
2123 gpiod_unexport(desc);
2124
2125 spin_lock_irqsave(&gpio_lock, flags);
2126
2127 gc = desc->gdev->chip;
2128 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
2129 if (gc->free) {
2130 spin_unlock_irqrestore(&gpio_lock, flags);
2131 might_sleep_if(gc->can_sleep);
2132 gc->free(gc, gpio_chip_hwgpio(desc));
2133 spin_lock_irqsave(&gpio_lock, flags);
2134 }
2135 kfree_const(desc->label);
2136 desc_set_label(desc, NULL);
2137 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2138 clear_bit(FLAG_REQUESTED, &desc->flags);
2139 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2140 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2141 clear_bit(FLAG_PULL_UP, &desc->flags);
2142 clear_bit(FLAG_PULL_DOWN, &desc->flags);
2143 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
2144 clear_bit(FLAG_EDGE_RISING, &desc->flags);
2145 clear_bit(FLAG_EDGE_FALLING, &desc->flags);
2146 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2147 #ifdef CONFIG_OF_DYNAMIC
2148 desc->hog = NULL;
2149 #endif
2150 #ifdef CONFIG_GPIO_CDEV
2151 WRITE_ONCE(desc->debounce_period_us, 0);
2152 #endif
2153 ret = true;
2154 }
2155
2156 spin_unlock_irqrestore(&gpio_lock, flags);
2157 blocking_notifier_call_chain(&desc->gdev->notifier,
2158 GPIOLINE_CHANGED_RELEASED, desc);
2159
2160 return ret;
2161 }
2162
gpiod_free(struct gpio_desc * desc)2163 void gpiod_free(struct gpio_desc *desc)
2164 {
2165 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2166 module_put(desc->gdev->owner);
2167 put_device(&desc->gdev->dev);
2168 } else {
2169 WARN_ON(extra_checks);
2170 }
2171 }
2172
2173 /**
2174 * gpiochip_is_requested - return string iff signal was requested
2175 * @gc: controller managing the signal
2176 * @offset: of signal within controller's 0..(ngpio - 1) range
2177 *
2178 * Returns NULL if the GPIO is not currently requested, else a string.
2179 * The string returned is the label passed to gpio_request(); if none has been
2180 * passed it is a meaningless, non-NULL constant.
2181 *
2182 * This function is for use by GPIO controller drivers. The label can
2183 * help with diagnostics, and knowing that the signal is used as a GPIO
2184 * can help avoid accidentally multiplexing it to another controller.
2185 */
gpiochip_is_requested(struct gpio_chip * gc,unsigned offset)2186 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned offset)
2187 {
2188 struct gpio_desc *desc;
2189
2190 if (offset >= gc->ngpio)
2191 return NULL;
2192
2193 desc = gpiochip_get_desc(gc, offset);
2194 if (IS_ERR(desc))
2195 return NULL;
2196
2197 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2198 return NULL;
2199 return desc->label;
2200 }
2201 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2202
2203 /**
2204 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2205 * @gc: GPIO chip
2206 * @hwnum: hardware number of the GPIO for which to request the descriptor
2207 * @label: label for the GPIO
2208 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2209 * specify things like line inversion semantics with the machine flags
2210 * such as GPIO_OUT_LOW
2211 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2212 * can be used to specify consumer semantics such as open drain
2213 *
2214 * Function allows GPIO chip drivers to request and use their own GPIO
2215 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2216 * function will not increase reference count of the GPIO chip module. This
2217 * allows the GPIO chip module to be unloaded as needed (we assume that the
2218 * GPIO chip driver handles freeing the GPIOs it has requested).
2219 *
2220 * Returns:
2221 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2222 * code on failure.
2223 */
gpiochip_request_own_desc(struct gpio_chip * gc,unsigned int hwnum,const char * label,enum gpio_lookup_flags lflags,enum gpiod_flags dflags)2224 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2225 unsigned int hwnum,
2226 const char *label,
2227 enum gpio_lookup_flags lflags,
2228 enum gpiod_flags dflags)
2229 {
2230 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2231 int ret;
2232
2233 if (IS_ERR(desc)) {
2234 chip_err(gc, "failed to get GPIO descriptor\n");
2235 return desc;
2236 }
2237
2238 ret = gpiod_request_commit(desc, label);
2239 if (ret < 0)
2240 return ERR_PTR(ret);
2241
2242 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2243 if (ret) {
2244 chip_err(gc, "setup of own GPIO %s failed\n", label);
2245 gpiod_free_commit(desc);
2246 return ERR_PTR(ret);
2247 }
2248
2249 return desc;
2250 }
2251 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2252
2253 /**
2254 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2255 * @desc: GPIO descriptor to free
2256 *
2257 * Function frees the given GPIO requested previously with
2258 * gpiochip_request_own_desc().
2259 */
gpiochip_free_own_desc(struct gpio_desc * desc)2260 void gpiochip_free_own_desc(struct gpio_desc *desc)
2261 {
2262 if (desc)
2263 gpiod_free_commit(desc);
2264 }
2265 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2266
2267 /*
2268 * Drivers MUST set GPIO direction before making get/set calls. In
2269 * some cases this is done in early boot, before IRQs are enabled.
2270 *
2271 * As a rule these aren't called more than once (except for drivers
2272 * using the open-drain emulation idiom) so these are natural places
2273 * to accumulate extra debugging checks. Note that we can't (yet)
2274 * rely on gpio_request() having been called beforehand.
2275 */
2276
gpio_do_set_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2277 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2278 unsigned long config)
2279 {
2280 if (!gc->set_config)
2281 return -ENOTSUPP;
2282
2283 return gc->set_config(gc, offset, config);
2284 }
2285
gpio_set_config(struct gpio_desc * desc,enum pin_config_param mode)2286 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2287 {
2288 struct gpio_chip *gc = desc->gdev->chip;
2289 unsigned long config;
2290 unsigned arg;
2291
2292 switch (mode) {
2293 case PIN_CONFIG_BIAS_PULL_DOWN:
2294 case PIN_CONFIG_BIAS_PULL_UP:
2295 arg = 1;
2296 break;
2297
2298 default:
2299 arg = 0;
2300 }
2301
2302 config = PIN_CONF_PACKED(mode, arg);
2303 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2304 }
2305
gpio_set_bias(struct gpio_desc * desc)2306 static int gpio_set_bias(struct gpio_desc *desc)
2307 {
2308 int bias = 0;
2309 int ret = 0;
2310
2311 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2312 bias = PIN_CONFIG_BIAS_DISABLE;
2313 else if (test_bit(FLAG_PULL_UP, &desc->flags))
2314 bias = PIN_CONFIG_BIAS_PULL_UP;
2315 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2316 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2317
2318 if (bias) {
2319 ret = gpio_set_config(desc, bias);
2320 if (ret != -ENOTSUPP)
2321 return ret;
2322 }
2323 return 0;
2324 }
2325
2326 /**
2327 * gpiod_direction_input - set the GPIO direction to input
2328 * @desc: GPIO to set to input
2329 *
2330 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2331 * be called safely on it.
2332 *
2333 * Return 0 in case of success, else an error code.
2334 */
gpiod_direction_input(struct gpio_desc * desc)2335 int gpiod_direction_input(struct gpio_desc *desc)
2336 {
2337 struct gpio_chip *gc;
2338 int ret = 0;
2339
2340 VALIDATE_DESC(desc);
2341 gc = desc->gdev->chip;
2342
2343 /*
2344 * It is legal to have no .get() and .direction_input() specified if
2345 * the chip is output-only, but you can't specify .direction_input()
2346 * and not support the .get() operation, that doesn't make sense.
2347 */
2348 if (!gc->get && gc->direction_input) {
2349 gpiod_warn(desc,
2350 "%s: missing get() but have direction_input()\n",
2351 __func__);
2352 return -EIO;
2353 }
2354
2355 /*
2356 * If we have a .direction_input() callback, things are simple,
2357 * just call it. Else we are some input-only chip so try to check the
2358 * direction (if .get_direction() is supported) else we silently
2359 * assume we are in input mode after this.
2360 */
2361 if (gc->direction_input) {
2362 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2363 } else if (gc->get_direction &&
2364 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2365 gpiod_warn(desc,
2366 "%s: missing direction_input() operation and line is output\n",
2367 __func__);
2368 return -EIO;
2369 }
2370 if (ret == 0) {
2371 clear_bit(FLAG_IS_OUT, &desc->flags);
2372 ret = gpio_set_bias(desc);
2373 }
2374
2375 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2376
2377 return ret;
2378 }
2379 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2380
gpiod_direction_output_raw_commit(struct gpio_desc * desc,int value)2381 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2382 {
2383 struct gpio_chip *gc = desc->gdev->chip;
2384 int val = !!value;
2385 int ret = 0;
2386
2387 /*
2388 * It's OK not to specify .direction_output() if the gpiochip is
2389 * output-only, but if there is then not even a .set() operation it
2390 * is pretty tricky to drive the output line.
2391 */
2392 if (!gc->set && !gc->direction_output) {
2393 gpiod_warn(desc,
2394 "%s: missing set() and direction_output() operations\n",
2395 __func__);
2396 return -EIO;
2397 }
2398
2399 if (gc->direction_output) {
2400 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2401 } else {
2402 /* Check that we are in output mode if we can */
2403 if (gc->get_direction &&
2404 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2405 gpiod_warn(desc,
2406 "%s: missing direction_output() operation\n",
2407 __func__);
2408 return -EIO;
2409 }
2410 /*
2411 * If we can't actively set the direction, we are some
2412 * output-only chip, so just drive the output as desired.
2413 */
2414 gc->set(gc, gpio_chip_hwgpio(desc), val);
2415 }
2416
2417 if (!ret)
2418 set_bit(FLAG_IS_OUT, &desc->flags);
2419 trace_gpio_value(desc_to_gpio(desc), 0, val);
2420 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2421 return ret;
2422 }
2423
2424 /**
2425 * gpiod_direction_output_raw - set the GPIO direction to output
2426 * @desc: GPIO to set to output
2427 * @value: initial output value of the GPIO
2428 *
2429 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2430 * be called safely on it. The initial value of the output must be specified
2431 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2432 *
2433 * Return 0 in case of success, else an error code.
2434 */
gpiod_direction_output_raw(struct gpio_desc * desc,int value)2435 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2436 {
2437 VALIDATE_DESC(desc);
2438 return gpiod_direction_output_raw_commit(desc, value);
2439 }
2440 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2441
2442 /**
2443 * gpiod_direction_output - set the GPIO direction to output
2444 * @desc: GPIO to set to output
2445 * @value: initial output value of the GPIO
2446 *
2447 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2448 * be called safely on it. The initial value of the output must be specified
2449 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2450 * account.
2451 *
2452 * Return 0 in case of success, else an error code.
2453 */
gpiod_direction_output(struct gpio_desc * desc,int value)2454 int gpiod_direction_output(struct gpio_desc *desc, int value)
2455 {
2456 int ret;
2457
2458 VALIDATE_DESC(desc);
2459 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2460 value = !value;
2461 else
2462 value = !!value;
2463
2464 /* GPIOs used for enabled IRQs shall not be set as output */
2465 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2466 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2467 gpiod_err(desc,
2468 "%s: tried to set a GPIO tied to an IRQ as output\n",
2469 __func__);
2470 return -EIO;
2471 }
2472
2473 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2474 /* First see if we can enable open drain in hardware */
2475 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2476 if (!ret)
2477 goto set_output_value;
2478 /* Emulate open drain by not actively driving the line high */
2479 if (value) {
2480 ret = gpiod_direction_input(desc);
2481 goto set_output_flag;
2482 }
2483 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2484 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2485 if (!ret)
2486 goto set_output_value;
2487 /* Emulate open source by not actively driving the line low */
2488 if (!value) {
2489 ret = gpiod_direction_input(desc);
2490 goto set_output_flag;
2491 }
2492 } else {
2493 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2494 }
2495
2496 set_output_value:
2497 ret = gpio_set_bias(desc);
2498 if (ret)
2499 return ret;
2500 return gpiod_direction_output_raw_commit(desc, value);
2501
2502 set_output_flag:
2503 /*
2504 * When emulating open-source or open-drain functionalities by not
2505 * actively driving the line (setting mode to input) we still need to
2506 * set the IS_OUT flag or otherwise we won't be able to set the line
2507 * value anymore.
2508 */
2509 if (ret == 0)
2510 set_bit(FLAG_IS_OUT, &desc->flags);
2511 return ret;
2512 }
2513 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2514
2515 /**
2516 * gpiod_set_config - sets @config for a GPIO
2517 * @desc: descriptor of the GPIO for which to set the configuration
2518 * @config: Same packed config format as generic pinconf
2519 *
2520 * Returns:
2521 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2522 * configuration.
2523 */
gpiod_set_config(struct gpio_desc * desc,unsigned long config)2524 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2525 {
2526 struct gpio_chip *gc;
2527
2528 VALIDATE_DESC(desc);
2529 gc = desc->gdev->chip;
2530
2531 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2532 }
2533 EXPORT_SYMBOL_GPL(gpiod_set_config);
2534
2535 /**
2536 * gpiod_set_debounce - sets @debounce time for a GPIO
2537 * @desc: descriptor of the GPIO for which to set debounce time
2538 * @debounce: debounce time in microseconds
2539 *
2540 * Returns:
2541 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2542 * debounce time.
2543 */
gpiod_set_debounce(struct gpio_desc * desc,unsigned debounce)2544 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2545 {
2546 unsigned long config;
2547
2548 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2549 return gpiod_set_config(desc, config);
2550 }
2551 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2552
2553 /**
2554 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2555 * @desc: descriptor of the GPIO for which to configure persistence
2556 * @transitory: True to lose state on suspend or reset, false for persistence
2557 *
2558 * Returns:
2559 * 0 on success, otherwise a negative error code.
2560 */
gpiod_set_transitory(struct gpio_desc * desc,bool transitory)2561 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2562 {
2563 struct gpio_chip *gc;
2564 unsigned long packed;
2565 int gpio;
2566 int rc;
2567
2568 VALIDATE_DESC(desc);
2569 /*
2570 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2571 * persistence state.
2572 */
2573 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2574
2575 /* If the driver supports it, set the persistence state now */
2576 gc = desc->gdev->chip;
2577 if (!gc->set_config)
2578 return 0;
2579
2580 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2581 !transitory);
2582 gpio = gpio_chip_hwgpio(desc);
2583 rc = gpio_do_set_config(gc, gpio, packed);
2584 if (rc == -ENOTSUPP) {
2585 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2586 gpio);
2587 return 0;
2588 }
2589
2590 return rc;
2591 }
2592 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2593
2594 /**
2595 * gpiod_is_active_low - test whether a GPIO is active-low or not
2596 * @desc: the gpio descriptor to test
2597 *
2598 * Returns 1 if the GPIO is active-low, 0 otherwise.
2599 */
gpiod_is_active_low(const struct gpio_desc * desc)2600 int gpiod_is_active_low(const struct gpio_desc *desc)
2601 {
2602 VALIDATE_DESC(desc);
2603 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2604 }
2605 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2606
2607 /**
2608 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2609 * @desc: the gpio descriptor to change
2610 */
gpiod_toggle_active_low(struct gpio_desc * desc)2611 void gpiod_toggle_active_low(struct gpio_desc *desc)
2612 {
2613 VALIDATE_DESC_VOID(desc);
2614 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2615 }
2616 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2617
2618 /* I/O calls are only valid after configuration completed; the relevant
2619 * "is this a valid GPIO" error checks should already have been done.
2620 *
2621 * "Get" operations are often inlinable as reading a pin value register,
2622 * and masking the relevant bit in that register.
2623 *
2624 * When "set" operations are inlinable, they involve writing that mask to
2625 * one register to set a low value, or a different register to set it high.
2626 * Otherwise locking is needed, so there may be little value to inlining.
2627 *
2628 *------------------------------------------------------------------------
2629 *
2630 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2631 * have requested the GPIO. That can include implicit requesting by
2632 * a direction setting call. Marking a gpio as requested locks its chip
2633 * in memory, guaranteeing that these table lookups need no more locking
2634 * and that gpiochip_remove() will fail.
2635 *
2636 * REVISIT when debugging, consider adding some instrumentation to ensure
2637 * that the GPIO was actually requested.
2638 */
2639
gpiod_get_raw_value_commit(const struct gpio_desc * desc)2640 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2641 {
2642 struct gpio_chip *gc;
2643 int offset;
2644 int value;
2645
2646 gc = desc->gdev->chip;
2647 offset = gpio_chip_hwgpio(desc);
2648 value = gc->get ? gc->get(gc, offset) : -EIO;
2649 value = value < 0 ? value : !!value;
2650 trace_gpio_value(desc_to_gpio(desc), 1, value);
2651 return value;
2652 }
2653
gpio_chip_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)2654 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2655 unsigned long *mask, unsigned long *bits)
2656 {
2657 if (gc->get_multiple)
2658 return gc->get_multiple(gc, mask, bits);
2659 if (gc->get) {
2660 int i, value;
2661
2662 for_each_set_bit(i, mask, gc->ngpio) {
2663 value = gc->get(gc, i);
2664 if (value < 0)
2665 return value;
2666 __assign_bit(i, bits, value);
2667 }
2668 return 0;
2669 }
2670 return -EIO;
2671 }
2672
gpiod_get_array_value_complex(bool raw,bool can_sleep,unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2673 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2674 unsigned int array_size,
2675 struct gpio_desc **desc_array,
2676 struct gpio_array *array_info,
2677 unsigned long *value_bitmap)
2678 {
2679 int ret, i = 0;
2680
2681 /*
2682 * Validate array_info against desc_array and its size.
2683 * It should immediately follow desc_array if both
2684 * have been obtained from the same gpiod_get_array() call.
2685 */
2686 if (array_info && array_info->desc == desc_array &&
2687 array_size <= array_info->size &&
2688 (void *)array_info == desc_array + array_info->size) {
2689 if (!can_sleep)
2690 WARN_ON(array_info->chip->can_sleep);
2691
2692 ret = gpio_chip_get_multiple(array_info->chip,
2693 array_info->get_mask,
2694 value_bitmap);
2695 if (ret)
2696 return ret;
2697
2698 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2699 bitmap_xor(value_bitmap, value_bitmap,
2700 array_info->invert_mask, array_size);
2701
2702 i = find_first_zero_bit(array_info->get_mask, array_size);
2703 if (i == array_size)
2704 return 0;
2705 } else {
2706 array_info = NULL;
2707 }
2708
2709 while (i < array_size) {
2710 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2711 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2712 unsigned long *mask, *bits;
2713 int first, j, ret;
2714
2715 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2716 mask = fastpath;
2717 } else {
2718 mask = kmalloc_array(2 * BITS_TO_LONGS(gc->ngpio),
2719 sizeof(*mask),
2720 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2721 if (!mask)
2722 return -ENOMEM;
2723 }
2724
2725 bits = mask + BITS_TO_LONGS(gc->ngpio);
2726 bitmap_zero(mask, gc->ngpio);
2727
2728 if (!can_sleep)
2729 WARN_ON(gc->can_sleep);
2730
2731 /* collect all inputs belonging to the same chip */
2732 first = i;
2733 do {
2734 const struct gpio_desc *desc = desc_array[i];
2735 int hwgpio = gpio_chip_hwgpio(desc);
2736
2737 __set_bit(hwgpio, mask);
2738 i++;
2739
2740 if (array_info)
2741 i = find_next_zero_bit(array_info->get_mask,
2742 array_size, i);
2743 } while ((i < array_size) &&
2744 (desc_array[i]->gdev->chip == gc));
2745
2746 ret = gpio_chip_get_multiple(gc, mask, bits);
2747 if (ret) {
2748 if (mask != fastpath)
2749 kfree(mask);
2750 return ret;
2751 }
2752
2753 for (j = first; j < i; ) {
2754 const struct gpio_desc *desc = desc_array[j];
2755 int hwgpio = gpio_chip_hwgpio(desc);
2756 int value = test_bit(hwgpio, bits);
2757
2758 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2759 value = !value;
2760 __assign_bit(j, value_bitmap, value);
2761 trace_gpio_value(desc_to_gpio(desc), 1, value);
2762 j++;
2763
2764 if (array_info)
2765 j = find_next_zero_bit(array_info->get_mask, i,
2766 j);
2767 }
2768
2769 if (mask != fastpath)
2770 kfree(mask);
2771 }
2772 return 0;
2773 }
2774
2775 /**
2776 * gpiod_get_raw_value() - return a gpio's raw value
2777 * @desc: gpio whose value will be returned
2778 *
2779 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2780 * its ACTIVE_LOW status, or negative errno on failure.
2781 *
2782 * This function can be called from contexts where we cannot sleep, and will
2783 * complain if the GPIO chip functions potentially sleep.
2784 */
gpiod_get_raw_value(const struct gpio_desc * desc)2785 int gpiod_get_raw_value(const struct gpio_desc *desc)
2786 {
2787 VALIDATE_DESC(desc);
2788 /* Should be using gpiod_get_raw_value_cansleep() */
2789 WARN_ON(desc->gdev->chip->can_sleep);
2790 return gpiod_get_raw_value_commit(desc);
2791 }
2792 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2793
2794 /**
2795 * gpiod_get_value() - return a gpio's value
2796 * @desc: gpio whose value will be returned
2797 *
2798 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2799 * account, or negative errno on failure.
2800 *
2801 * This function can be called from contexts where we cannot sleep, and will
2802 * complain if the GPIO chip functions potentially sleep.
2803 */
gpiod_get_value(const struct gpio_desc * desc)2804 int gpiod_get_value(const struct gpio_desc *desc)
2805 {
2806 int value;
2807
2808 VALIDATE_DESC(desc);
2809 /* Should be using gpiod_get_value_cansleep() */
2810 WARN_ON(desc->gdev->chip->can_sleep);
2811
2812 value = gpiod_get_raw_value_commit(desc);
2813 if (value < 0)
2814 return value;
2815
2816 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2817 value = !value;
2818
2819 return value;
2820 }
2821 EXPORT_SYMBOL_GPL(gpiod_get_value);
2822
2823 /**
2824 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2825 * @array_size: number of elements in the descriptor array / value bitmap
2826 * @desc_array: array of GPIO descriptors whose values will be read
2827 * @array_info: information on applicability of fast bitmap processing path
2828 * @value_bitmap: bitmap to store the read values
2829 *
2830 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2831 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2832 * else an error code.
2833 *
2834 * This function can be called from contexts where we cannot sleep,
2835 * and it will complain if the GPIO chip functions potentially sleep.
2836 */
gpiod_get_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2837 int gpiod_get_raw_array_value(unsigned int array_size,
2838 struct gpio_desc **desc_array,
2839 struct gpio_array *array_info,
2840 unsigned long *value_bitmap)
2841 {
2842 if (!desc_array)
2843 return -EINVAL;
2844 return gpiod_get_array_value_complex(true, false, array_size,
2845 desc_array, array_info,
2846 value_bitmap);
2847 }
2848 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2849
2850 /**
2851 * gpiod_get_array_value() - read values from an array of GPIOs
2852 * @array_size: number of elements in the descriptor array / value bitmap
2853 * @desc_array: array of GPIO descriptors whose values will be read
2854 * @array_info: information on applicability of fast bitmap processing path
2855 * @value_bitmap: bitmap to store the read values
2856 *
2857 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2858 * into account. Return 0 in case of success, else an error code.
2859 *
2860 * This function can be called from contexts where we cannot sleep,
2861 * and it will complain if the GPIO chip functions potentially sleep.
2862 */
gpiod_get_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2863 int gpiod_get_array_value(unsigned int array_size,
2864 struct gpio_desc **desc_array,
2865 struct gpio_array *array_info,
2866 unsigned long *value_bitmap)
2867 {
2868 if (!desc_array)
2869 return -EINVAL;
2870 return gpiod_get_array_value_complex(false, false, array_size,
2871 desc_array, array_info,
2872 value_bitmap);
2873 }
2874 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2875
2876 /*
2877 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2878 * @desc: gpio descriptor whose state need to be set.
2879 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2880 */
gpio_set_open_drain_value_commit(struct gpio_desc * desc,bool value)2881 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2882 {
2883 int ret = 0;
2884 struct gpio_chip *gc = desc->gdev->chip;
2885 int offset = gpio_chip_hwgpio(desc);
2886
2887 if (value) {
2888 ret = gc->direction_input(gc, offset);
2889 } else {
2890 ret = gc->direction_output(gc, offset, 0);
2891 if (!ret)
2892 set_bit(FLAG_IS_OUT, &desc->flags);
2893 }
2894 trace_gpio_direction(desc_to_gpio(desc), value, ret);
2895 if (ret < 0)
2896 gpiod_err(desc,
2897 "%s: Error in set_value for open drain err %d\n",
2898 __func__, ret);
2899 }
2900
2901 /*
2902 * _gpio_set_open_source_value() - Set the open source gpio's value.
2903 * @desc: gpio descriptor whose state need to be set.
2904 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2905 */
gpio_set_open_source_value_commit(struct gpio_desc * desc,bool value)2906 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2907 {
2908 int ret = 0;
2909 struct gpio_chip *gc = desc->gdev->chip;
2910 int offset = gpio_chip_hwgpio(desc);
2911
2912 if (value) {
2913 ret = gc->direction_output(gc, offset, 1);
2914 if (!ret)
2915 set_bit(FLAG_IS_OUT, &desc->flags);
2916 } else {
2917 ret = gc->direction_input(gc, offset);
2918 }
2919 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2920 if (ret < 0)
2921 gpiod_err(desc,
2922 "%s: Error in set_value for open source err %d\n",
2923 __func__, ret);
2924 }
2925
gpiod_set_raw_value_commit(struct gpio_desc * desc,bool value)2926 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2927 {
2928 struct gpio_chip *gc;
2929
2930 gc = desc->gdev->chip;
2931 trace_gpio_value(desc_to_gpio(desc), 0, value);
2932 gc->set(gc, gpio_chip_hwgpio(desc), value);
2933 }
2934
2935 /*
2936 * set multiple outputs on the same chip;
2937 * use the chip's set_multiple function if available;
2938 * otherwise set the outputs sequentially;
2939 * @chip: the GPIO chip we operate on
2940 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2941 * defines which outputs are to be changed
2942 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2943 * defines the values the outputs specified by mask are to be set to
2944 */
gpio_chip_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)2945 static void gpio_chip_set_multiple(struct gpio_chip *gc,
2946 unsigned long *mask, unsigned long *bits)
2947 {
2948 if (gc->set_multiple) {
2949 gc->set_multiple(gc, mask, bits);
2950 } else {
2951 unsigned int i;
2952
2953 /* set outputs if the corresponding mask bit is set */
2954 for_each_set_bit(i, mask, gc->ngpio)
2955 gc->set(gc, i, test_bit(i, bits));
2956 }
2957 }
2958
gpiod_set_array_value_complex(bool raw,bool can_sleep,unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2959 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2960 unsigned int array_size,
2961 struct gpio_desc **desc_array,
2962 struct gpio_array *array_info,
2963 unsigned long *value_bitmap)
2964 {
2965 int i = 0;
2966
2967 /*
2968 * Validate array_info against desc_array and its size.
2969 * It should immediately follow desc_array if both
2970 * have been obtained from the same gpiod_get_array() call.
2971 */
2972 if (array_info && array_info->desc == desc_array &&
2973 array_size <= array_info->size &&
2974 (void *)array_info == desc_array + array_info->size) {
2975 if (!can_sleep)
2976 WARN_ON(array_info->chip->can_sleep);
2977
2978 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2979 bitmap_xor(value_bitmap, value_bitmap,
2980 array_info->invert_mask, array_size);
2981
2982 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2983 value_bitmap);
2984
2985 i = find_first_zero_bit(array_info->set_mask, array_size);
2986 if (i == array_size)
2987 return 0;
2988 } else {
2989 array_info = NULL;
2990 }
2991
2992 while (i < array_size) {
2993 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2994 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2995 unsigned long *mask, *bits;
2996 int count = 0;
2997
2998 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2999 mask = fastpath;
3000 } else {
3001 mask = kmalloc_array(2 * BITS_TO_LONGS(gc->ngpio),
3002 sizeof(*mask),
3003 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3004 if (!mask)
3005 return -ENOMEM;
3006 }
3007
3008 bits = mask + BITS_TO_LONGS(gc->ngpio);
3009 bitmap_zero(mask, gc->ngpio);
3010
3011 if (!can_sleep)
3012 WARN_ON(gc->can_sleep);
3013
3014 do {
3015 struct gpio_desc *desc = desc_array[i];
3016 int hwgpio = gpio_chip_hwgpio(desc);
3017 int value = test_bit(i, value_bitmap);
3018
3019 /*
3020 * Pins applicable for fast input but not for
3021 * fast output processing may have been already
3022 * inverted inside the fast path, skip them.
3023 */
3024 if (!raw && !(array_info &&
3025 test_bit(i, array_info->invert_mask)) &&
3026 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3027 value = !value;
3028 trace_gpio_value(desc_to_gpio(desc), 0, value);
3029 /*
3030 * collect all normal outputs belonging to the same chip
3031 * open drain and open source outputs are set individually
3032 */
3033 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3034 gpio_set_open_drain_value_commit(desc, value);
3035 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3036 gpio_set_open_source_value_commit(desc, value);
3037 } else {
3038 __set_bit(hwgpio, mask);
3039 __assign_bit(hwgpio, bits, value);
3040 count++;
3041 }
3042 i++;
3043
3044 if (array_info)
3045 i = find_next_zero_bit(array_info->set_mask,
3046 array_size, i);
3047 } while ((i < array_size) &&
3048 (desc_array[i]->gdev->chip == gc));
3049 /* push collected bits to outputs */
3050 if (count != 0)
3051 gpio_chip_set_multiple(gc, mask, bits);
3052
3053 if (mask != fastpath)
3054 kfree(mask);
3055 }
3056 return 0;
3057 }
3058
3059 /**
3060 * gpiod_set_raw_value() - assign a gpio's raw value
3061 * @desc: gpio whose value will be assigned
3062 * @value: value to assign
3063 *
3064 * Set the raw value of the GPIO, i.e. the value of its physical line without
3065 * regard for its ACTIVE_LOW status.
3066 *
3067 * This function can be called from contexts where we cannot sleep, and will
3068 * complain if the GPIO chip functions potentially sleep.
3069 */
gpiod_set_raw_value(struct gpio_desc * desc,int value)3070 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3071 {
3072 VALIDATE_DESC_VOID(desc);
3073 /* Should be using gpiod_set_raw_value_cansleep() */
3074 WARN_ON(desc->gdev->chip->can_sleep);
3075 gpiod_set_raw_value_commit(desc, value);
3076 }
3077 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3078
3079 /**
3080 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3081 * @desc: the descriptor to set the value on
3082 * @value: value to set
3083 *
3084 * This sets the value of a GPIO line backing a descriptor, applying
3085 * different semantic quirks like active low and open drain/source
3086 * handling.
3087 */
gpiod_set_value_nocheck(struct gpio_desc * desc,int value)3088 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3089 {
3090 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3091 value = !value;
3092 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3093 gpio_set_open_drain_value_commit(desc, value);
3094 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3095 gpio_set_open_source_value_commit(desc, value);
3096 else
3097 gpiod_set_raw_value_commit(desc, value);
3098 }
3099
3100 /**
3101 * gpiod_set_value() - assign a gpio's value
3102 * @desc: gpio whose value will be assigned
3103 * @value: value to assign
3104 *
3105 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3106 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3107 *
3108 * This function can be called from contexts where we cannot sleep, and will
3109 * complain if the GPIO chip functions potentially sleep.
3110 */
gpiod_set_value(struct gpio_desc * desc,int value)3111 void gpiod_set_value(struct gpio_desc *desc, int value)
3112 {
3113 VALIDATE_DESC_VOID(desc);
3114 /* Should be using gpiod_set_value_cansleep() */
3115 WARN_ON(desc->gdev->chip->can_sleep);
3116 gpiod_set_value_nocheck(desc, value);
3117 }
3118 EXPORT_SYMBOL_GPL(gpiod_set_value);
3119
3120 /**
3121 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3122 * @array_size: number of elements in the descriptor array / value bitmap
3123 * @desc_array: array of GPIO descriptors whose values will be assigned
3124 * @array_info: information on applicability of fast bitmap processing path
3125 * @value_bitmap: bitmap of values to assign
3126 *
3127 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3128 * without regard for their ACTIVE_LOW status.
3129 *
3130 * This function can be called from contexts where we cannot sleep, and will
3131 * complain if the GPIO chip functions potentially sleep.
3132 */
gpiod_set_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3133 int gpiod_set_raw_array_value(unsigned int array_size,
3134 struct gpio_desc **desc_array,
3135 struct gpio_array *array_info,
3136 unsigned long *value_bitmap)
3137 {
3138 if (!desc_array)
3139 return -EINVAL;
3140 return gpiod_set_array_value_complex(true, false, array_size,
3141 desc_array, array_info, value_bitmap);
3142 }
3143 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3144
3145 /**
3146 * gpiod_set_array_value() - assign values to an array of GPIOs
3147 * @array_size: number of elements in the descriptor array / value bitmap
3148 * @desc_array: array of GPIO descriptors whose values will be assigned
3149 * @array_info: information on applicability of fast bitmap processing path
3150 * @value_bitmap: bitmap of values to assign
3151 *
3152 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3153 * into account.
3154 *
3155 * This function can be called from contexts where we cannot sleep, and will
3156 * complain if the GPIO chip functions potentially sleep.
3157 */
gpiod_set_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3158 int gpiod_set_array_value(unsigned int array_size,
3159 struct gpio_desc **desc_array,
3160 struct gpio_array *array_info,
3161 unsigned long *value_bitmap)
3162 {
3163 if (!desc_array)
3164 return -EINVAL;
3165 return gpiod_set_array_value_complex(false, false, array_size,
3166 desc_array, array_info,
3167 value_bitmap);
3168 }
3169 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3170
3171 /**
3172 * gpiod_cansleep() - report whether gpio value access may sleep
3173 * @desc: gpio to check
3174 *
3175 */
gpiod_cansleep(const struct gpio_desc * desc)3176 int gpiod_cansleep(const struct gpio_desc *desc)
3177 {
3178 VALIDATE_DESC(desc);
3179 return desc->gdev->chip->can_sleep;
3180 }
3181 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3182
3183 /**
3184 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3185 * @desc: gpio to set the consumer name on
3186 * @name: the new consumer name
3187 */
gpiod_set_consumer_name(struct gpio_desc * desc,const char * name)3188 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3189 {
3190 VALIDATE_DESC(desc);
3191 if (name) {
3192 name = kstrdup_const(name, GFP_KERNEL);
3193 if (!name)
3194 return -ENOMEM;
3195 }
3196
3197 kfree_const(desc->label);
3198 desc_set_label(desc, name);
3199
3200 return 0;
3201 }
3202 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3203
3204 /**
3205 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3206 * @desc: gpio whose IRQ will be returned (already requested)
3207 *
3208 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3209 * error.
3210 */
gpiod_to_irq(const struct gpio_desc * desc)3211 int gpiod_to_irq(const struct gpio_desc *desc)
3212 {
3213 struct gpio_chip *gc;
3214 int offset;
3215
3216 /*
3217 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3218 * requires this function to not return zero on an invalid descriptor
3219 * but rather a negative error number.
3220 */
3221 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3222 return -EINVAL;
3223
3224 gc = desc->gdev->chip;
3225 offset = gpio_chip_hwgpio(desc);
3226 if (gc->to_irq) {
3227 int retirq = gc->to_irq(gc, offset);
3228
3229 /* Zero means NO_IRQ */
3230 if (!retirq)
3231 return -ENXIO;
3232
3233 return retirq;
3234 }
3235 #ifdef CONFIG_GPIOLIB_IRQCHIP
3236 if (gc->irq.chip) {
3237 /*
3238 * Avoid race condition with other code, which tries to lookup
3239 * an IRQ before the irqchip has been properly registered,
3240 * i.e. while gpiochip is still being brought up.
3241 */
3242 return -EPROBE_DEFER;
3243 }
3244 #endif
3245 return -ENXIO;
3246 }
3247 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3248
3249 /**
3250 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3251 * @gc: the chip the GPIO to lock belongs to
3252 * @offset: the offset of the GPIO to lock as IRQ
3253 *
3254 * This is used directly by GPIO drivers that want to lock down
3255 * a certain GPIO line to be used for IRQs.
3256 */
gpiochip_lock_as_irq(struct gpio_chip * gc,unsigned int offset)3257 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3258 {
3259 struct gpio_desc *desc;
3260
3261 desc = gpiochip_get_desc(gc, offset);
3262 if (IS_ERR(desc))
3263 return PTR_ERR(desc);
3264
3265 /*
3266 * If it's fast: flush the direction setting if something changed
3267 * behind our back
3268 */
3269 if (!gc->can_sleep && gc->get_direction) {
3270 int dir = gpiod_get_direction(desc);
3271
3272 if (dir < 0) {
3273 chip_err(gc, "%s: cannot get GPIO direction\n",
3274 __func__);
3275 return dir;
3276 }
3277 }
3278
3279 /* To be valid for IRQ the line needs to be input or open drain */
3280 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3281 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3282 chip_err(gc,
3283 "%s: tried to flag a GPIO set as output for IRQ\n",
3284 __func__);
3285 return -EIO;
3286 }
3287
3288 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3289 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3290
3291 /*
3292 * If the consumer has not set up a label (such as when the
3293 * IRQ is referenced from .to_irq()) we set up a label here
3294 * so it is clear this is used as an interrupt.
3295 */
3296 if (!desc->label)
3297 desc_set_label(desc, "interrupt");
3298
3299 return 0;
3300 }
3301 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3302
3303 /**
3304 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3305 * @gc: the chip the GPIO to lock belongs to
3306 * @offset: the offset of the GPIO to lock as IRQ
3307 *
3308 * This is used directly by GPIO drivers that want to indicate
3309 * that a certain GPIO is no longer used exclusively for IRQ.
3310 */
gpiochip_unlock_as_irq(struct gpio_chip * gc,unsigned int offset)3311 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3312 {
3313 struct gpio_desc *desc;
3314
3315 desc = gpiochip_get_desc(gc, offset);
3316 if (IS_ERR(desc))
3317 return;
3318
3319 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3320 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3321
3322 /* If we only had this marking, erase it */
3323 if (desc->label && !strcmp(desc->label, "interrupt"))
3324 desc_set_label(desc, NULL);
3325 }
3326 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3327
gpiochip_disable_irq(struct gpio_chip * gc,unsigned int offset)3328 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3329 {
3330 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3331
3332 if (!IS_ERR(desc) &&
3333 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3334 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3335 }
3336 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3337
gpiochip_enable_irq(struct gpio_chip * gc,unsigned int offset)3338 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3339 {
3340 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3341
3342 if (!IS_ERR(desc) &&
3343 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3344 /*
3345 * We must not be output when using IRQ UNLESS we are
3346 * open drain.
3347 */
3348 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3349 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3350 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3351 }
3352 }
3353 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3354
gpiochip_line_is_irq(struct gpio_chip * gc,unsigned int offset)3355 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3356 {
3357 if (offset >= gc->ngpio)
3358 return false;
3359
3360 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3361 }
3362 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3363
gpiochip_reqres_irq(struct gpio_chip * gc,unsigned int offset)3364 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3365 {
3366 int ret;
3367
3368 if (!try_module_get(gc->gpiodev->owner))
3369 return -ENODEV;
3370
3371 ret = gpiochip_lock_as_irq(gc, offset);
3372 if (ret) {
3373 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3374 module_put(gc->gpiodev->owner);
3375 return ret;
3376 }
3377 return 0;
3378 }
3379 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3380
gpiochip_relres_irq(struct gpio_chip * gc,unsigned int offset)3381 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3382 {
3383 gpiochip_unlock_as_irq(gc, offset);
3384 module_put(gc->gpiodev->owner);
3385 }
3386 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3387
gpiochip_line_is_open_drain(struct gpio_chip * gc,unsigned int offset)3388 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3389 {
3390 if (offset >= gc->ngpio)
3391 return false;
3392
3393 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3394 }
3395 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3396
gpiochip_line_is_open_source(struct gpio_chip * gc,unsigned int offset)3397 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3398 {
3399 if (offset >= gc->ngpio)
3400 return false;
3401
3402 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3403 }
3404 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3405
gpiochip_line_is_persistent(struct gpio_chip * gc,unsigned int offset)3406 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3407 {
3408 if (offset >= gc->ngpio)
3409 return false;
3410
3411 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3412 }
3413 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3414
3415 /**
3416 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3417 * @desc: gpio whose value will be returned
3418 *
3419 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3420 * its ACTIVE_LOW status, or negative errno on failure.
3421 *
3422 * This function is to be called from contexts that can sleep.
3423 */
gpiod_get_raw_value_cansleep(const struct gpio_desc * desc)3424 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3425 {
3426 might_sleep_if(extra_checks);
3427 VALIDATE_DESC(desc);
3428 return gpiod_get_raw_value_commit(desc);
3429 }
3430 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3431
3432 /**
3433 * gpiod_get_value_cansleep() - return a gpio's value
3434 * @desc: gpio whose value will be returned
3435 *
3436 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3437 * account, or negative errno on failure.
3438 *
3439 * This function is to be called from contexts that can sleep.
3440 */
gpiod_get_value_cansleep(const struct gpio_desc * desc)3441 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3442 {
3443 int value;
3444
3445 might_sleep_if(extra_checks);
3446 VALIDATE_DESC(desc);
3447 value = gpiod_get_raw_value_commit(desc);
3448 if (value < 0)
3449 return value;
3450
3451 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3452 value = !value;
3453
3454 return value;
3455 }
3456 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3457
3458 /**
3459 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3460 * @array_size: number of elements in the descriptor array / value bitmap
3461 * @desc_array: array of GPIO descriptors whose values will be read
3462 * @array_info: information on applicability of fast bitmap processing path
3463 * @value_bitmap: bitmap to store the read values
3464 *
3465 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3466 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3467 * else an error code.
3468 *
3469 * This function is to be called from contexts that can sleep.
3470 */
gpiod_get_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3471 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3472 struct gpio_desc **desc_array,
3473 struct gpio_array *array_info,
3474 unsigned long *value_bitmap)
3475 {
3476 might_sleep_if(extra_checks);
3477 if (!desc_array)
3478 return -EINVAL;
3479 return gpiod_get_array_value_complex(true, true, array_size,
3480 desc_array, array_info,
3481 value_bitmap);
3482 }
3483 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3484
3485 /**
3486 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3487 * @array_size: number of elements in the descriptor array / value bitmap
3488 * @desc_array: array of GPIO descriptors whose values will be read
3489 * @array_info: information on applicability of fast bitmap processing path
3490 * @value_bitmap: bitmap to store the read values
3491 *
3492 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3493 * into account. Return 0 in case of success, else an error code.
3494 *
3495 * This function is to be called from contexts that can sleep.
3496 */
gpiod_get_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3497 int gpiod_get_array_value_cansleep(unsigned int array_size,
3498 struct gpio_desc **desc_array,
3499 struct gpio_array *array_info,
3500 unsigned long *value_bitmap)
3501 {
3502 might_sleep_if(extra_checks);
3503 if (!desc_array)
3504 return -EINVAL;
3505 return gpiod_get_array_value_complex(false, true, array_size,
3506 desc_array, array_info,
3507 value_bitmap);
3508 }
3509 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3510
3511 /**
3512 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3513 * @desc: gpio whose value will be assigned
3514 * @value: value to assign
3515 *
3516 * Set the raw value of the GPIO, i.e. the value of its physical line without
3517 * regard for its ACTIVE_LOW status.
3518 *
3519 * This function is to be called from contexts that can sleep.
3520 */
gpiod_set_raw_value_cansleep(struct gpio_desc * desc,int value)3521 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3522 {
3523 might_sleep_if(extra_checks);
3524 VALIDATE_DESC_VOID(desc);
3525 gpiod_set_raw_value_commit(desc, value);
3526 }
3527 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3528
3529 /**
3530 * gpiod_set_value_cansleep() - assign a gpio's value
3531 * @desc: gpio whose value will be assigned
3532 * @value: value to assign
3533 *
3534 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3535 * account
3536 *
3537 * This function is to be called from contexts that can sleep.
3538 */
gpiod_set_value_cansleep(struct gpio_desc * desc,int value)3539 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3540 {
3541 might_sleep_if(extra_checks);
3542 VALIDATE_DESC_VOID(desc);
3543 gpiod_set_value_nocheck(desc, value);
3544 }
3545 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3546
3547 /**
3548 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3549 * @array_size: number of elements in the descriptor array / value bitmap
3550 * @desc_array: array of GPIO descriptors whose values will be assigned
3551 * @array_info: information on applicability of fast bitmap processing path
3552 * @value_bitmap: bitmap of values to assign
3553 *
3554 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3555 * without regard for their ACTIVE_LOW status.
3556 *
3557 * This function is to be called from contexts that can sleep.
3558 */
gpiod_set_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3559 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3560 struct gpio_desc **desc_array,
3561 struct gpio_array *array_info,
3562 unsigned long *value_bitmap)
3563 {
3564 might_sleep_if(extra_checks);
3565 if (!desc_array)
3566 return -EINVAL;
3567 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3568 array_info, value_bitmap);
3569 }
3570 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3571
3572 /**
3573 * gpiod_add_lookup_tables() - register GPIO device consumers
3574 * @tables: list of tables of consumers to register
3575 * @n: number of tables in the list
3576 */
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)3577 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3578 {
3579 unsigned int i;
3580
3581 mutex_lock(&gpio_lookup_lock);
3582
3583 for (i = 0; i < n; i++)
3584 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3585
3586 mutex_unlock(&gpio_lookup_lock);
3587 }
3588
3589 /**
3590 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3591 * @array_size: number of elements in the descriptor array / value bitmap
3592 * @desc_array: array of GPIO descriptors whose values will be assigned
3593 * @array_info: information on applicability of fast bitmap processing path
3594 * @value_bitmap: bitmap of values to assign
3595 *
3596 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3597 * into account.
3598 *
3599 * This function is to be called from contexts that can sleep.
3600 */
gpiod_set_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3601 int gpiod_set_array_value_cansleep(unsigned int array_size,
3602 struct gpio_desc **desc_array,
3603 struct gpio_array *array_info,
3604 unsigned long *value_bitmap)
3605 {
3606 might_sleep_if(extra_checks);
3607 if (!desc_array)
3608 return -EINVAL;
3609 return gpiod_set_array_value_complex(false, true, array_size,
3610 desc_array, array_info,
3611 value_bitmap);
3612 }
3613 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3614
3615 /**
3616 * gpiod_add_lookup_table() - register GPIO device consumers
3617 * @table: table of consumers to register
3618 */
gpiod_add_lookup_table(struct gpiod_lookup_table * table)3619 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3620 {
3621 mutex_lock(&gpio_lookup_lock);
3622
3623 list_add_tail(&table->list, &gpio_lookup_list);
3624
3625 mutex_unlock(&gpio_lookup_lock);
3626 }
3627 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3628
3629 /**
3630 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3631 * @table: table of consumers to unregister
3632 */
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)3633 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3634 {
3635 mutex_lock(&gpio_lookup_lock);
3636
3637 list_del(&table->list);
3638
3639 mutex_unlock(&gpio_lookup_lock);
3640 }
3641 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3642
3643 /**
3644 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3645 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3646 */
gpiod_add_hogs(struct gpiod_hog * hogs)3647 void gpiod_add_hogs(struct gpiod_hog *hogs)
3648 {
3649 struct gpio_chip *gc;
3650 struct gpiod_hog *hog;
3651
3652 mutex_lock(&gpio_machine_hogs_mutex);
3653
3654 for (hog = &hogs[0]; hog->chip_label; hog++) {
3655 list_add_tail(&hog->list, &gpio_machine_hogs);
3656
3657 /*
3658 * The chip may have been registered earlier, so check if it
3659 * exists and, if so, try to hog the line now.
3660 */
3661 gc = find_chip_by_name(hog->chip_label);
3662 if (gc)
3663 gpiochip_machine_hog(gc, hog);
3664 }
3665
3666 mutex_unlock(&gpio_machine_hogs_mutex);
3667 }
3668 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3669
gpiod_find_lookup_table(struct device * dev)3670 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3671 {
3672 const char *dev_id = dev ? dev_name(dev) : NULL;
3673 struct gpiod_lookup_table *table;
3674
3675 mutex_lock(&gpio_lookup_lock);
3676
3677 list_for_each_entry(table, &gpio_lookup_list, list) {
3678 if (table->dev_id && dev_id) {
3679 /*
3680 * Valid strings on both ends, must be identical to have
3681 * a match
3682 */
3683 if (!strcmp(table->dev_id, dev_id))
3684 goto found;
3685 } else {
3686 /*
3687 * One of the pointers is NULL, so both must be to have
3688 * a match
3689 */
3690 if (dev_id == table->dev_id)
3691 goto found;
3692 }
3693 }
3694 table = NULL;
3695
3696 found:
3697 mutex_unlock(&gpio_lookup_lock);
3698 return table;
3699 }
3700
gpiod_find(struct device * dev,const char * con_id,unsigned int idx,unsigned long * flags)3701 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3702 unsigned int idx, unsigned long *flags)
3703 {
3704 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3705 struct gpiod_lookup_table *table;
3706 struct gpiod_lookup *p;
3707
3708 table = gpiod_find_lookup_table(dev);
3709 if (!table)
3710 return desc;
3711
3712 for (p = &table->table[0]; p->key; p++) {
3713 struct gpio_chip *gc;
3714
3715 /* idx must always match exactly */
3716 if (p->idx != idx)
3717 continue;
3718
3719 /* If the lookup entry has a con_id, require exact match */
3720 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3721 continue;
3722
3723 if (p->chip_hwnum == U16_MAX) {
3724 desc = gpio_name_to_desc(p->key);
3725 if (desc) {
3726 *flags = p->flags;
3727 return desc;
3728 }
3729
3730 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3731 p->key);
3732 return ERR_PTR(-EPROBE_DEFER);
3733 }
3734
3735 gc = find_chip_by_name(p->key);
3736
3737 if (!gc) {
3738 /*
3739 * As the lookup table indicates a chip with
3740 * p->key should exist, assume it may
3741 * still appear later and let the interested
3742 * consumer be probed again or let the Deferred
3743 * Probe infrastructure handle the error.
3744 */
3745 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3746 p->key);
3747 return ERR_PTR(-EPROBE_DEFER);
3748 }
3749
3750 if (gc->ngpio <= p->chip_hwnum) {
3751 dev_err(dev,
3752 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3753 idx, p->chip_hwnum, gc->ngpio - 1,
3754 gc->label);
3755 return ERR_PTR(-EINVAL);
3756 }
3757
3758 desc = gpiochip_get_desc(gc, p->chip_hwnum);
3759 *flags = p->flags;
3760
3761 return desc;
3762 }
3763
3764 return desc;
3765 }
3766
platform_gpio_count(struct device * dev,const char * con_id)3767 static int platform_gpio_count(struct device *dev, const char *con_id)
3768 {
3769 struct gpiod_lookup_table *table;
3770 struct gpiod_lookup *p;
3771 unsigned int count = 0;
3772
3773 table = gpiod_find_lookup_table(dev);
3774 if (!table)
3775 return -ENOENT;
3776
3777 for (p = &table->table[0]; p->key; p++) {
3778 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3779 (!con_id && !p->con_id))
3780 count++;
3781 }
3782 if (!count)
3783 return -ENOENT;
3784
3785 return count;
3786 }
3787
3788 /**
3789 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3790 * @fwnode: handle of the firmware node
3791 * @con_id: function within the GPIO consumer
3792 * @index: index of the GPIO to obtain for the consumer
3793 * @flags: GPIO initialization flags
3794 * @label: label to attach to the requested GPIO
3795 *
3796 * This function can be used for drivers that get their configuration
3797 * from opaque firmware.
3798 *
3799 * The function properly finds the corresponding GPIO using whatever is the
3800 * underlying firmware interface and then makes sure that the GPIO
3801 * descriptor is requested before it is returned to the caller.
3802 *
3803 * Returns:
3804 * On successful request the GPIO pin is configured in accordance with
3805 * provided @flags.
3806 *
3807 * In case of error an ERR_PTR() is returned.
3808 */
fwnode_gpiod_get_index(struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)3809 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3810 const char *con_id, int index,
3811 enum gpiod_flags flags,
3812 const char *label)
3813 {
3814 struct gpio_desc *desc;
3815 char prop_name[32]; /* 32 is max size of property name */
3816 unsigned int i;
3817
3818 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3819 if (con_id)
3820 snprintf(prop_name, sizeof(prop_name), "%s-%s",
3821 con_id, gpio_suffixes[i]);
3822 else
3823 snprintf(prop_name, sizeof(prop_name), "%s",
3824 gpio_suffixes[i]);
3825
3826 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3827 label);
3828 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
3829 break;
3830 }
3831
3832 return desc;
3833 }
3834 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3835
3836 /**
3837 * gpiod_count - return the number of GPIOs associated with a device / function
3838 * or -ENOENT if no GPIO has been assigned to the requested function
3839 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3840 * @con_id: function within the GPIO consumer
3841 */
gpiod_count(struct device * dev,const char * con_id)3842 int gpiod_count(struct device *dev, const char *con_id)
3843 {
3844 int count = -ENOENT;
3845
3846 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3847 count = of_gpio_get_count(dev, con_id);
3848 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3849 count = acpi_gpio_count(dev, con_id);
3850
3851 if (count < 0)
3852 count = platform_gpio_count(dev, con_id);
3853
3854 return count;
3855 }
3856 EXPORT_SYMBOL_GPL(gpiod_count);
3857
3858 /**
3859 * gpiod_get - obtain a GPIO for a given GPIO function
3860 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3861 * @con_id: function within the GPIO consumer
3862 * @flags: optional GPIO initialization flags
3863 *
3864 * Return the GPIO descriptor corresponding to the function con_id of device
3865 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3866 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3867 */
gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)3868 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3869 enum gpiod_flags flags)
3870 {
3871 return gpiod_get_index(dev, con_id, 0, flags);
3872 }
3873 EXPORT_SYMBOL_GPL(gpiod_get);
3874
3875 /**
3876 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3877 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3878 * @con_id: function within the GPIO consumer
3879 * @flags: optional GPIO initialization flags
3880 *
3881 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3882 * the requested function it will return NULL. This is convenient for drivers
3883 * that need to handle optional GPIOs.
3884 */
gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)3885 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3886 const char *con_id,
3887 enum gpiod_flags flags)
3888 {
3889 return gpiod_get_index_optional(dev, con_id, 0, flags);
3890 }
3891 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3892
3893
3894 /**
3895 * gpiod_configure_flags - helper function to configure a given GPIO
3896 * @desc: gpio whose value will be assigned
3897 * @con_id: function within the GPIO consumer
3898 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3899 * of_find_gpio() or of_get_gpio_hog()
3900 * @dflags: gpiod_flags - optional GPIO initialization flags
3901 *
3902 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3903 * requested function and/or index, or another IS_ERR() code if an error
3904 * occurred while trying to acquire the GPIO.
3905 */
gpiod_configure_flags(struct gpio_desc * desc,const char * con_id,unsigned long lflags,enum gpiod_flags dflags)3906 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3907 unsigned long lflags, enum gpiod_flags dflags)
3908 {
3909 int ret;
3910
3911 if (lflags & GPIO_ACTIVE_LOW)
3912 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3913
3914 if (lflags & GPIO_OPEN_DRAIN)
3915 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3916 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3917 /*
3918 * This enforces open drain mode from the consumer side.
3919 * This is necessary for some busses like I2C, but the lookup
3920 * should *REALLY* have specified them as open drain in the
3921 * first place, so print a little warning here.
3922 */
3923 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3924 gpiod_warn(desc,
3925 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3926 }
3927
3928 if (lflags & GPIO_OPEN_SOURCE)
3929 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3930
3931 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3932 gpiod_err(desc,
3933 "both pull-up and pull-down enabled, invalid configuration\n");
3934 return -EINVAL;
3935 }
3936
3937 if (lflags & GPIO_PULL_UP)
3938 set_bit(FLAG_PULL_UP, &desc->flags);
3939 else if (lflags & GPIO_PULL_DOWN)
3940 set_bit(FLAG_PULL_DOWN, &desc->flags);
3941
3942 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3943 if (ret < 0)
3944 return ret;
3945
3946 /* No particular flag request, return here... */
3947 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3948 gpiod_dbg(desc, "no flags found for %s\n", con_id);
3949 return 0;
3950 }
3951
3952 /* Process flags */
3953 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3954 ret = gpiod_direction_output(desc,
3955 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3956 else
3957 ret = gpiod_direction_input(desc);
3958
3959 return ret;
3960 }
3961
3962 /**
3963 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3964 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3965 * @con_id: function within the GPIO consumer
3966 * @idx: index of the GPIO to obtain in the consumer
3967 * @flags: optional GPIO initialization flags
3968 *
3969 * This variant of gpiod_get() allows to access GPIOs other than the first
3970 * defined one for functions that define several GPIOs.
3971 *
3972 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3973 * requested function and/or index, or another IS_ERR() code if an error
3974 * occurred while trying to acquire the GPIO.
3975 */
gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)3976 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3977 const char *con_id,
3978 unsigned int idx,
3979 enum gpiod_flags flags)
3980 {
3981 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3982 struct gpio_desc *desc = NULL;
3983 int ret;
3984 /* Maybe we have a device name, maybe not */
3985 const char *devname = dev ? dev_name(dev) : "?";
3986
3987 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3988
3989 if (dev) {
3990 /* Using device tree? */
3991 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3992 dev_dbg(dev, "using device tree for GPIO lookup\n");
3993 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3994 } else if (ACPI_COMPANION(dev)) {
3995 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3996 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3997 }
3998 }
3999
4000 /*
4001 * Either we are not using DT or ACPI, or their lookup did not return
4002 * a result. In that case, use platform lookup as a fallback.
4003 */
4004 if (!desc || desc == ERR_PTR(-ENOENT)) {
4005 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4006 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4007 }
4008
4009 if (IS_ERR(desc)) {
4010 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4011 return desc;
4012 }
4013
4014 /*
4015 * If a connection label was passed use that, else attempt to use
4016 * the device name as label
4017 */
4018 ret = gpiod_request(desc, con_id ? con_id : devname);
4019 if (ret < 0) {
4020 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4021 /*
4022 * This happens when there are several consumers for
4023 * the same GPIO line: we just return here without
4024 * further initialization. It is a bit if a hack.
4025 * This is necessary to support fixed regulators.
4026 *
4027 * FIXME: Make this more sane and safe.
4028 */
4029 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4030 con_id ? con_id : devname);
4031 return desc;
4032 } else {
4033 return ERR_PTR(ret);
4034 }
4035 }
4036
4037 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4038 if (ret < 0) {
4039 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4040 gpiod_put(desc);
4041 return ERR_PTR(ret);
4042 }
4043
4044 blocking_notifier_call_chain(&desc->gdev->notifier,
4045 GPIOLINE_CHANGED_REQUESTED, desc);
4046
4047 return desc;
4048 }
4049 EXPORT_SYMBOL_GPL(gpiod_get_index);
4050
4051 /**
4052 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4053 * @fwnode: handle of the firmware node
4054 * @propname: name of the firmware property representing the GPIO
4055 * @index: index of the GPIO to obtain for the consumer
4056 * @dflags: GPIO initialization flags
4057 * @label: label to attach to the requested GPIO
4058 *
4059 * This function can be used for drivers that get their configuration
4060 * from opaque firmware.
4061 *
4062 * The function properly finds the corresponding GPIO using whatever is the
4063 * underlying firmware interface and then makes sure that the GPIO
4064 * descriptor is requested before it is returned to the caller.
4065 *
4066 * Returns:
4067 * On successful request the GPIO pin is configured in accordance with
4068 * provided @dflags.
4069 *
4070 * In case of error an ERR_PTR() is returned.
4071 */
fwnode_get_named_gpiod(struct fwnode_handle * fwnode,const char * propname,int index,enum gpiod_flags dflags,const char * label)4072 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4073 const char *propname, int index,
4074 enum gpiod_flags dflags,
4075 const char *label)
4076 {
4077 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4078 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4079 int ret;
4080
4081 if (!fwnode)
4082 return ERR_PTR(-EINVAL);
4083
4084 if (is_of_node(fwnode)) {
4085 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4086 propname, index,
4087 dflags,
4088 label);
4089 return desc;
4090 } else if (is_acpi_node(fwnode)) {
4091 struct acpi_gpio_info info;
4092
4093 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4094 if (IS_ERR(desc))
4095 return desc;
4096
4097 acpi_gpio_update_gpiod_flags(&dflags, &info);
4098 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4099 }
4100
4101 /* Currently only ACPI takes this path */
4102 ret = gpiod_request(desc, label);
4103 if (ret)
4104 return ERR_PTR(ret);
4105
4106 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4107 if (ret < 0) {
4108 gpiod_put(desc);
4109 return ERR_PTR(ret);
4110 }
4111
4112 blocking_notifier_call_chain(&desc->gdev->notifier,
4113 GPIOLINE_CHANGED_REQUESTED, desc);
4114
4115 return desc;
4116 }
4117 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4118
4119 /**
4120 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4121 * function
4122 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4123 * @con_id: function within the GPIO consumer
4124 * @index: index of the GPIO to obtain in the consumer
4125 * @flags: optional GPIO initialization flags
4126 *
4127 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4128 * specified index was assigned to the requested function it will return NULL.
4129 * This is convenient for drivers that need to handle optional GPIOs.
4130 */
gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)4131 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4132 const char *con_id,
4133 unsigned int index,
4134 enum gpiod_flags flags)
4135 {
4136 struct gpio_desc *desc;
4137
4138 desc = gpiod_get_index(dev, con_id, index, flags);
4139 if (IS_ERR(desc)) {
4140 if (PTR_ERR(desc) == -ENOENT)
4141 return NULL;
4142 }
4143
4144 return desc;
4145 }
4146 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4147
4148 /**
4149 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4150 * @desc: gpio whose value will be assigned
4151 * @name: gpio line name
4152 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4153 * of_find_gpio() or of_get_gpio_hog()
4154 * @dflags: gpiod_flags - optional GPIO initialization flags
4155 */
gpiod_hog(struct gpio_desc * desc,const char * name,unsigned long lflags,enum gpiod_flags dflags)4156 int gpiod_hog(struct gpio_desc *desc, const char *name,
4157 unsigned long lflags, enum gpiod_flags dflags)
4158 {
4159 struct gpio_chip *gc;
4160 struct gpio_desc *local_desc;
4161 int hwnum;
4162 int ret;
4163
4164 gc = gpiod_to_chip(desc);
4165 hwnum = gpio_chip_hwgpio(desc);
4166
4167 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4168 lflags, dflags);
4169 if (IS_ERR(local_desc)) {
4170 ret = PTR_ERR(local_desc);
4171 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4172 name, gc->label, hwnum, ret);
4173 return ret;
4174 }
4175
4176 /* Mark GPIO as hogged so it can be identified and removed later */
4177 set_bit(FLAG_IS_HOGGED, &desc->flags);
4178
4179 gpiod_info(desc, "hogged as %s%s\n",
4180 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4181 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4182 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4183
4184 return 0;
4185 }
4186
4187 /**
4188 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4189 * @gc: gpio chip to act on
4190 */
gpiochip_free_hogs(struct gpio_chip * gc)4191 static void gpiochip_free_hogs(struct gpio_chip *gc)
4192 {
4193 int id;
4194
4195 for (id = 0; id < gc->ngpio; id++) {
4196 if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
4197 gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
4198 }
4199 }
4200
4201 /**
4202 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4203 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4204 * @con_id: function within the GPIO consumer
4205 * @flags: optional GPIO initialization flags
4206 *
4207 * This function acquires all the GPIOs defined under a given function.
4208 *
4209 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4210 * no GPIO has been assigned to the requested function, or another IS_ERR()
4211 * code if an error occurred while trying to acquire the GPIOs.
4212 */
gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)4213 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4214 const char *con_id,
4215 enum gpiod_flags flags)
4216 {
4217 struct gpio_desc *desc;
4218 struct gpio_descs *descs;
4219 struct gpio_array *array_info = NULL;
4220 struct gpio_chip *gc;
4221 int count, bitmap_size;
4222
4223 count = gpiod_count(dev, con_id);
4224 if (count < 0)
4225 return ERR_PTR(count);
4226
4227 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4228 if (!descs)
4229 return ERR_PTR(-ENOMEM);
4230
4231 for (descs->ndescs = 0; descs->ndescs < count; ) {
4232 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4233 if (IS_ERR(desc)) {
4234 gpiod_put_array(descs);
4235 return ERR_CAST(desc);
4236 }
4237
4238 descs->desc[descs->ndescs] = desc;
4239
4240 gc = gpiod_to_chip(desc);
4241 /*
4242 * If pin hardware number of array member 0 is also 0, select
4243 * its chip as a candidate for fast bitmap processing path.
4244 */
4245 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4246 struct gpio_descs *array;
4247
4248 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4249 gc->ngpio : count);
4250
4251 array = kzalloc(struct_size(descs, desc, count) +
4252 struct_size(array_info, invert_mask,
4253 3 * bitmap_size), GFP_KERNEL);
4254 if (!array) {
4255 gpiod_put_array(descs);
4256 return ERR_PTR(-ENOMEM);
4257 }
4258
4259 memcpy(array, descs,
4260 struct_size(descs, desc, descs->ndescs + 1));
4261 kfree(descs);
4262
4263 descs = array;
4264 array_info = (void *)(descs->desc + count);
4265 array_info->get_mask = array_info->invert_mask +
4266 bitmap_size;
4267 array_info->set_mask = array_info->get_mask +
4268 bitmap_size;
4269
4270 array_info->desc = descs->desc;
4271 array_info->size = count;
4272 array_info->chip = gc;
4273 bitmap_set(array_info->get_mask, descs->ndescs,
4274 count - descs->ndescs);
4275 bitmap_set(array_info->set_mask, descs->ndescs,
4276 count - descs->ndescs);
4277 descs->info = array_info;
4278 }
4279 /* Unmark array members which don't belong to the 'fast' chip */
4280 if (array_info && array_info->chip != gc) {
4281 __clear_bit(descs->ndescs, array_info->get_mask);
4282 __clear_bit(descs->ndescs, array_info->set_mask);
4283 }
4284 /*
4285 * Detect array members which belong to the 'fast' chip
4286 * but their pins are not in hardware order.
4287 */
4288 else if (array_info &&
4289 gpio_chip_hwgpio(desc) != descs->ndescs) {
4290 /*
4291 * Don't use fast path if all array members processed so
4292 * far belong to the same chip as this one but its pin
4293 * hardware number is different from its array index.
4294 */
4295 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4296 array_info = NULL;
4297 } else {
4298 __clear_bit(descs->ndescs,
4299 array_info->get_mask);
4300 __clear_bit(descs->ndescs,
4301 array_info->set_mask);
4302 }
4303 } else if (array_info) {
4304 /* Exclude open drain or open source from fast output */
4305 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4306 gpiochip_line_is_open_source(gc, descs->ndescs))
4307 __clear_bit(descs->ndescs,
4308 array_info->set_mask);
4309 /* Identify 'fast' pins which require invertion */
4310 if (gpiod_is_active_low(desc))
4311 __set_bit(descs->ndescs,
4312 array_info->invert_mask);
4313 }
4314
4315 descs->ndescs++;
4316 }
4317 if (array_info)
4318 dev_dbg(dev,
4319 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4320 array_info->chip->label, array_info->size,
4321 *array_info->get_mask, *array_info->set_mask,
4322 *array_info->invert_mask);
4323 return descs;
4324 }
4325 EXPORT_SYMBOL_GPL(gpiod_get_array);
4326
4327 /**
4328 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4329 * function
4330 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4331 * @con_id: function within the GPIO consumer
4332 * @flags: optional GPIO initialization flags
4333 *
4334 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4335 * assigned to the requested function it will return NULL.
4336 */
gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4337 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4338 const char *con_id,
4339 enum gpiod_flags flags)
4340 {
4341 struct gpio_descs *descs;
4342
4343 descs = gpiod_get_array(dev, con_id, flags);
4344 if (PTR_ERR(descs) == -ENOENT)
4345 return NULL;
4346
4347 return descs;
4348 }
4349 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4350
4351 /**
4352 * gpiod_put - dispose of a GPIO descriptor
4353 * @desc: GPIO descriptor to dispose of
4354 *
4355 * No descriptor can be used after gpiod_put() has been called on it.
4356 */
gpiod_put(struct gpio_desc * desc)4357 void gpiod_put(struct gpio_desc *desc)
4358 {
4359 if (desc)
4360 gpiod_free(desc);
4361 }
4362 EXPORT_SYMBOL_GPL(gpiod_put);
4363
4364 /**
4365 * gpiod_put_array - dispose of multiple GPIO descriptors
4366 * @descs: struct gpio_descs containing an array of descriptors
4367 */
gpiod_put_array(struct gpio_descs * descs)4368 void gpiod_put_array(struct gpio_descs *descs)
4369 {
4370 unsigned int i;
4371
4372 for (i = 0; i < descs->ndescs; i++)
4373 gpiod_put(descs->desc[i]);
4374
4375 kfree(descs);
4376 }
4377 EXPORT_SYMBOL_GPL(gpiod_put_array);
4378
gpiolib_dev_init(void)4379 static int __init gpiolib_dev_init(void)
4380 {
4381 int ret;
4382
4383 /* Register GPIO sysfs bus */
4384 ret = bus_register(&gpio_bus_type);
4385 if (ret < 0) {
4386 pr_err("gpiolib: could not register GPIO bus type\n");
4387 return ret;
4388 }
4389
4390 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4391 if (ret < 0) {
4392 pr_err("gpiolib: failed to allocate char dev region\n");
4393 bus_unregister(&gpio_bus_type);
4394 return ret;
4395 }
4396
4397 gpiolib_initialized = true;
4398 gpiochip_setup_devs();
4399
4400 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4401 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4402 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4403
4404 return ret;
4405 }
4406 core_initcall(gpiolib_dev_init);
4407
4408 #ifdef CONFIG_DEBUG_FS
4409
gpiolib_dbg_show(struct seq_file * s,struct gpio_device * gdev)4410 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4411 {
4412 unsigned i;
4413 struct gpio_chip *gc = gdev->chip;
4414 unsigned gpio = gdev->base;
4415 struct gpio_desc *gdesc = &gdev->descs[0];
4416 bool is_out;
4417 bool is_irq;
4418 bool active_low;
4419
4420 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4421 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4422 if (gdesc->name) {
4423 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4424 gpio, gdesc->name);
4425 }
4426 continue;
4427 }
4428
4429 gpiod_get_direction(gdesc);
4430 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4431 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4432 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4433 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4434 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4435 is_out ? "out" : "in ",
4436 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
4437 is_irq ? "IRQ " : "",
4438 active_low ? "ACTIVE LOW" : "");
4439 seq_printf(s, "\n");
4440 }
4441 }
4442
gpiolib_seq_start(struct seq_file * s,loff_t * pos)4443 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4444 {
4445 unsigned long flags;
4446 struct gpio_device *gdev = NULL;
4447 loff_t index = *pos;
4448
4449 s->private = "";
4450
4451 spin_lock_irqsave(&gpio_lock, flags);
4452 list_for_each_entry(gdev, &gpio_devices, list)
4453 if (index-- == 0) {
4454 spin_unlock_irqrestore(&gpio_lock, flags);
4455 return gdev;
4456 }
4457 spin_unlock_irqrestore(&gpio_lock, flags);
4458
4459 return NULL;
4460 }
4461
gpiolib_seq_next(struct seq_file * s,void * v,loff_t * pos)4462 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4463 {
4464 unsigned long flags;
4465 struct gpio_device *gdev = v;
4466 void *ret = NULL;
4467
4468 spin_lock_irqsave(&gpio_lock, flags);
4469 if (list_is_last(&gdev->list, &gpio_devices))
4470 ret = NULL;
4471 else
4472 ret = list_entry(gdev->list.next, struct gpio_device, list);
4473 spin_unlock_irqrestore(&gpio_lock, flags);
4474
4475 s->private = "\n";
4476 ++*pos;
4477
4478 return ret;
4479 }
4480
gpiolib_seq_stop(struct seq_file * s,void * v)4481 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4482 {
4483 }
4484
gpiolib_seq_show(struct seq_file * s,void * v)4485 static int gpiolib_seq_show(struct seq_file *s, void *v)
4486 {
4487 struct gpio_device *gdev = v;
4488 struct gpio_chip *gc = gdev->chip;
4489 struct device *parent;
4490
4491 if (!gc) {
4492 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4493 dev_name(&gdev->dev));
4494 return 0;
4495 }
4496
4497 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4498 dev_name(&gdev->dev),
4499 gdev->base, gdev->base + gdev->ngpio - 1);
4500 parent = gc->parent;
4501 if (parent)
4502 seq_printf(s, ", parent: %s/%s",
4503 parent->bus ? parent->bus->name : "no-bus",
4504 dev_name(parent));
4505 if (gc->label)
4506 seq_printf(s, ", %s", gc->label);
4507 if (gc->can_sleep)
4508 seq_printf(s, ", can sleep");
4509 seq_printf(s, ":\n");
4510
4511 if (gc->dbg_show)
4512 gc->dbg_show(s, gc);
4513 else
4514 gpiolib_dbg_show(s, gdev);
4515
4516 return 0;
4517 }
4518
4519 static const struct seq_operations gpiolib_sops = {
4520 .start = gpiolib_seq_start,
4521 .next = gpiolib_seq_next,
4522 .stop = gpiolib_seq_stop,
4523 .show = gpiolib_seq_show,
4524 };
4525 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4526
gpiolib_debugfs_init(void)4527 static int __init gpiolib_debugfs_init(void)
4528 {
4529 /* /sys/kernel/debug/gpio */
4530 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4531 return 0;
4532 }
4533 subsys_initcall(gpiolib_debugfs_init);
4534
4535 #endif /* DEBUG_FS */
4536