1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/bitmap.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/interrupt.h>
7 #include <linux/irq.h>
8 #include <linux/spinlock.h>
9 #include <linux/list.h>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/debugfs.h>
13 #include <linux/seq_file.h>
14 #include <linux/gpio.h>
15 #include <linux/idr.h>
16 #include <linux/slab.h>
17 #include <linux/acpi.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/gpio/machine.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/fs.h>
22 #include <linux/compat.h>
23 #include <linux/file.h>
24 #include <uapi/linux/gpio.h>
25
26 #include "gpiolib.h"
27 #include "gpiolib-of.h"
28 #include "gpiolib-acpi.h"
29 #include "gpiolib-cdev.h"
30 #include "gpiolib-sysfs.h"
31
32 #define CREATE_TRACE_POINTS
33 #include <trace/events/gpio.h>
34
35 /* Implementation infrastructure for GPIO interfaces.
36 *
37 * The GPIO programming interface allows for inlining speed-critical
38 * get/set operations for common cases, so that access to SOC-integrated
39 * GPIOs can sometimes cost only an instruction or two per bit.
40 */
41
42
43 /* When debugging, extend minimal trust to callers and platform code.
44 * Also emit diagnostic messages that may help initial bringup, when
45 * board setup or driver bugs are most common.
46 *
47 * Otherwise, minimize overhead in what may be bitbanging codepaths.
48 */
49 #ifdef DEBUG
50 #define extra_checks 1
51 #else
52 #define extra_checks 0
53 #endif
54
55 /* Device and char device-related information */
56 static DEFINE_IDA(gpio_ida);
57 static dev_t gpio_devt;
58 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
59 static int gpio_bus_match(struct device *dev, struct device_driver *drv);
60 static struct bus_type gpio_bus_type = {
61 .name = "gpio",
62 .match = gpio_bus_match,
63 };
64
65 /*
66 * Number of GPIOs to use for the fast path in set array
67 */
68 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
69
70 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
71 * While any GPIO is requested, its gpio_chip is not removable;
72 * each GPIO's "requested" flag serves as a lock and refcount.
73 */
74 DEFINE_SPINLOCK(gpio_lock);
75
76 static DEFINE_MUTEX(gpio_lookup_lock);
77 static LIST_HEAD(gpio_lookup_list);
78 LIST_HEAD(gpio_devices);
79
80 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
81 static LIST_HEAD(gpio_machine_hogs);
82
83 static void gpiochip_free_hogs(struct gpio_chip *gc);
84 static int gpiochip_add_irqchip(struct gpio_chip *gc,
85 struct lock_class_key *lock_key,
86 struct lock_class_key *request_key);
87 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
88 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
89 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
90 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
91
92 static bool gpiolib_initialized;
93
desc_set_label(struct gpio_desc * d,const char * label)94 static inline void desc_set_label(struct gpio_desc *d, const char *label)
95 {
96 d->label = label;
97 }
98
99 /**
100 * gpio_to_desc - Convert a GPIO number to its descriptor
101 * @gpio: global GPIO number
102 *
103 * Returns:
104 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
105 * with the given number exists in the system.
106 */
gpio_to_desc(unsigned gpio)107 struct gpio_desc *gpio_to_desc(unsigned gpio)
108 {
109 struct gpio_device *gdev;
110 unsigned long flags;
111
112 spin_lock_irqsave(&gpio_lock, flags);
113
114 list_for_each_entry(gdev, &gpio_devices, list) {
115 if (gdev->base <= gpio &&
116 gdev->base + gdev->ngpio > gpio) {
117 spin_unlock_irqrestore(&gpio_lock, flags);
118 return &gdev->descs[gpio - gdev->base];
119 }
120 }
121
122 spin_unlock_irqrestore(&gpio_lock, flags);
123
124 if (!gpio_is_valid(gpio))
125 pr_warn("invalid GPIO %d\n", gpio);
126
127 return NULL;
128 }
129 EXPORT_SYMBOL_GPL(gpio_to_desc);
130
131 /**
132 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
133 * hardware number for this chip
134 * @gc: GPIO chip
135 * @hwnum: hardware number of the GPIO for this chip
136 *
137 * Returns:
138 * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
139 * in the given chip for the specified hardware number.
140 */
gpiochip_get_desc(struct gpio_chip * gc,unsigned int hwnum)141 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
142 unsigned int hwnum)
143 {
144 struct gpio_device *gdev = gc->gpiodev;
145
146 if (hwnum >= gdev->ngpio)
147 return ERR_PTR(-EINVAL);
148
149 return &gdev->descs[hwnum];
150 }
151 EXPORT_SYMBOL_GPL(gpiochip_get_desc);
152
153 /**
154 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
155 * @desc: GPIO descriptor
156 *
157 * This should disappear in the future but is needed since we still
158 * use GPIO numbers for error messages and sysfs nodes.
159 *
160 * Returns:
161 * The global GPIO number for the GPIO specified by its descriptor.
162 */
desc_to_gpio(const struct gpio_desc * desc)163 int desc_to_gpio(const struct gpio_desc *desc)
164 {
165 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
166 }
167 EXPORT_SYMBOL_GPL(desc_to_gpio);
168
169
170 /**
171 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
172 * @desc: descriptor to return the chip of
173 */
gpiod_to_chip(const struct gpio_desc * desc)174 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
175 {
176 if (!desc || !desc->gdev)
177 return NULL;
178 return desc->gdev->chip;
179 }
180 EXPORT_SYMBOL_GPL(gpiod_to_chip);
181
182 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
gpiochip_find_base(int ngpio)183 static int gpiochip_find_base(int ngpio)
184 {
185 struct gpio_device *gdev;
186 int base = ARCH_NR_GPIOS - ngpio;
187
188 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
189 /* found a free space? */
190 if (gdev->base + gdev->ngpio <= base)
191 break;
192 /* nope, check the space right before the chip */
193 base = gdev->base - ngpio;
194 }
195
196 if (gpio_is_valid(base)) {
197 pr_debug("%s: found new base at %d\n", __func__, base);
198 return base;
199 } else {
200 pr_err("%s: cannot find free range\n", __func__);
201 return -ENOSPC;
202 }
203 }
204
205 /**
206 * gpiod_get_direction - return the current direction of a GPIO
207 * @desc: GPIO to get the direction of
208 *
209 * Returns 0 for output, 1 for input, or an error code in case of error.
210 *
211 * This function may sleep if gpiod_cansleep() is true.
212 */
gpiod_get_direction(struct gpio_desc * desc)213 int gpiod_get_direction(struct gpio_desc *desc)
214 {
215 struct gpio_chip *gc;
216 unsigned int offset;
217 int ret;
218
219 gc = gpiod_to_chip(desc);
220 offset = gpio_chip_hwgpio(desc);
221
222 /*
223 * Open drain emulation using input mode may incorrectly report
224 * input here, fix that up.
225 */
226 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
227 test_bit(FLAG_IS_OUT, &desc->flags))
228 return 0;
229
230 if (!gc->get_direction)
231 return -ENOTSUPP;
232
233 ret = gc->get_direction(gc, offset);
234 if (ret < 0)
235 return ret;
236
237 /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
238 if (ret > 0)
239 ret = 1;
240
241 assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
242
243 return ret;
244 }
245 EXPORT_SYMBOL_GPL(gpiod_get_direction);
246
247 /*
248 * Add a new chip to the global chips list, keeping the list of chips sorted
249 * by range(means [base, base + ngpio - 1]) order.
250 *
251 * Return -EBUSY if the new chip overlaps with some other chip's integer
252 * space.
253 */
gpiodev_add_to_list(struct gpio_device * gdev)254 static int gpiodev_add_to_list(struct gpio_device *gdev)
255 {
256 struct gpio_device *prev, *next;
257
258 if (list_empty(&gpio_devices)) {
259 /* initial entry in list */
260 list_add_tail(&gdev->list, &gpio_devices);
261 return 0;
262 }
263
264 next = list_entry(gpio_devices.next, struct gpio_device, list);
265 if (gdev->base + gdev->ngpio <= next->base) {
266 /* add before first entry */
267 list_add(&gdev->list, &gpio_devices);
268 return 0;
269 }
270
271 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
272 if (prev->base + prev->ngpio <= gdev->base) {
273 /* add behind last entry */
274 list_add_tail(&gdev->list, &gpio_devices);
275 return 0;
276 }
277
278 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
279 /* at the end of the list */
280 if (&next->list == &gpio_devices)
281 break;
282
283 /* add between prev and next */
284 if (prev->base + prev->ngpio <= gdev->base
285 && gdev->base + gdev->ngpio <= next->base) {
286 list_add(&gdev->list, &prev->list);
287 return 0;
288 }
289 }
290
291 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
292 return -EBUSY;
293 }
294
295 /*
296 * Convert a GPIO name to its descriptor
297 * Note that there is no guarantee that GPIO names are globally unique!
298 * Hence this function will return, if it exists, a reference to the first GPIO
299 * line found that matches the given name.
300 */
gpio_name_to_desc(const char * const name)301 static struct gpio_desc *gpio_name_to_desc(const char * const name)
302 {
303 struct gpio_device *gdev;
304 unsigned long flags;
305
306 if (!name)
307 return NULL;
308
309 spin_lock_irqsave(&gpio_lock, flags);
310
311 list_for_each_entry(gdev, &gpio_devices, list) {
312 int i;
313
314 for (i = 0; i != gdev->ngpio; ++i) {
315 struct gpio_desc *desc = &gdev->descs[i];
316
317 if (!desc->name)
318 continue;
319
320 if (!strcmp(desc->name, name)) {
321 spin_unlock_irqrestore(&gpio_lock, flags);
322 return desc;
323 }
324 }
325 }
326
327 spin_unlock_irqrestore(&gpio_lock, flags);
328
329 return NULL;
330 }
331
332 /*
333 * Take the names from gc->names and assign them to their GPIO descriptors.
334 * Warn if a name is already used for a GPIO line on a different GPIO chip.
335 *
336 * Note that:
337 * 1. Non-unique names are still accepted,
338 * 2. Name collisions within the same GPIO chip are not reported.
339 */
gpiochip_set_desc_names(struct gpio_chip * gc)340 static int gpiochip_set_desc_names(struct gpio_chip *gc)
341 {
342 struct gpio_device *gdev = gc->gpiodev;
343 int i;
344
345 /* First check all names if they are unique */
346 for (i = 0; i != gc->ngpio; ++i) {
347 struct gpio_desc *gpio;
348
349 gpio = gpio_name_to_desc(gc->names[i]);
350 if (gpio)
351 dev_warn(&gdev->dev,
352 "Detected name collision for GPIO name '%s'\n",
353 gc->names[i]);
354 }
355
356 /* Then add all names to the GPIO descriptors */
357 for (i = 0; i != gc->ngpio; ++i)
358 gdev->descs[i].name = gc->names[i];
359
360 return 0;
361 }
362
363 /*
364 * devprop_gpiochip_set_names - Set GPIO line names using device properties
365 * @chip: GPIO chip whose lines should be named, if possible
366 *
367 * Looks for device property "gpio-line-names" and if it exists assigns
368 * GPIO line names for the chip. The memory allocated for the assigned
369 * names belong to the underlying firmware node and should not be released
370 * by the caller.
371 */
devprop_gpiochip_set_names(struct gpio_chip * chip)372 static int devprop_gpiochip_set_names(struct gpio_chip *chip)
373 {
374 struct gpio_device *gdev = chip->gpiodev;
375 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
376 const char **names;
377 int ret, i;
378 int count;
379
380 count = fwnode_property_string_array_count(fwnode, "gpio-line-names");
381 if (count < 0)
382 return 0;
383
384 /*
385 * When offset is set in the driver side we assume the driver internally
386 * is using more than one gpiochip per the same device. We have to stop
387 * setting friendly names if the specified ones with 'gpio-line-names'
388 * are less than the offset in the device itself. This means all the
389 * lines are not present for every single pin within all the internal
390 * gpiochips.
391 */
392 if (count <= chip->offset) {
393 dev_warn(&gdev->dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
394 count, chip->offset);
395 return 0;
396 }
397
398 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
399 if (!names)
400 return -ENOMEM;
401
402 ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
403 names, count);
404 if (ret < 0) {
405 dev_warn(&gdev->dev, "failed to read GPIO line names\n");
406 kfree(names);
407 return ret;
408 }
409
410 /*
411 * When more that one gpiochip per device is used, 'count' can
412 * contain at most number gpiochips x chip->ngpio. We have to
413 * correctly distribute all defined lines taking into account
414 * chip->offset as starting point from where we will assign
415 * the names to pins from the 'names' array. Since property
416 * 'gpio-line-names' cannot contains gaps, we have to be sure
417 * we only assign those pins that really exists since chip->ngpio
418 * can be different of the chip->offset.
419 */
420 count = (count > chip->offset) ? count - chip->offset : count;
421 if (count > chip->ngpio)
422 count = chip->ngpio;
423
424 for (i = 0; i < count; i++)
425 gdev->descs[i].name = names[chip->offset + i];
426
427 kfree(names);
428
429 return 0;
430 }
431
gpiochip_allocate_mask(struct gpio_chip * gc)432 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
433 {
434 unsigned long *p;
435
436 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
437 if (!p)
438 return NULL;
439
440 /* Assume by default all GPIOs are valid */
441 bitmap_fill(p, gc->ngpio);
442
443 return p;
444 }
445
gpiochip_alloc_valid_mask(struct gpio_chip * gc)446 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
447 {
448 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
449 return 0;
450
451 gc->valid_mask = gpiochip_allocate_mask(gc);
452 if (!gc->valid_mask)
453 return -ENOMEM;
454
455 return 0;
456 }
457
gpiochip_init_valid_mask(struct gpio_chip * gc)458 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
459 {
460 if (gc->init_valid_mask)
461 return gc->init_valid_mask(gc,
462 gc->valid_mask,
463 gc->ngpio);
464
465 return 0;
466 }
467
gpiochip_free_valid_mask(struct gpio_chip * gc)468 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
469 {
470 bitmap_free(gc->valid_mask);
471 gc->valid_mask = NULL;
472 }
473
gpiochip_add_pin_ranges(struct gpio_chip * gc)474 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
475 {
476 if (gc->add_pin_ranges)
477 return gc->add_pin_ranges(gc);
478
479 return 0;
480 }
481
gpiochip_line_is_valid(const struct gpio_chip * gc,unsigned int offset)482 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
483 unsigned int offset)
484 {
485 /* No mask means all valid */
486 if (likely(!gc->valid_mask))
487 return true;
488 return test_bit(offset, gc->valid_mask);
489 }
490 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
491
gpiodevice_release(struct device * dev)492 static void gpiodevice_release(struct device *dev)
493 {
494 struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
495 unsigned long flags;
496
497 spin_lock_irqsave(&gpio_lock, flags);
498 list_del(&gdev->list);
499 spin_unlock_irqrestore(&gpio_lock, flags);
500
501 ida_free(&gpio_ida, gdev->id);
502 kfree_const(gdev->label);
503 kfree(gdev->descs);
504 kfree(gdev);
505 }
506
507 #ifdef CONFIG_GPIO_CDEV
508 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
509 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
510 #else
511 /*
512 * gpiolib_cdev_register() indirectly calls device_add(), which is still
513 * required even when cdev is not selected.
514 */
515 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
516 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
517 #endif
518
gpiochip_setup_dev(struct gpio_device * gdev)519 static int gpiochip_setup_dev(struct gpio_device *gdev)
520 {
521 int ret;
522
523 ret = gcdev_register(gdev, gpio_devt);
524 if (ret)
525 return ret;
526
527 /* From this point, the .release() function cleans up gpio_device */
528 gdev->dev.release = gpiodevice_release;
529
530 ret = gpiochip_sysfs_register(gdev);
531 if (ret)
532 goto err_remove_device;
533
534 dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
535 gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
536
537 return 0;
538
539 err_remove_device:
540 gcdev_unregister(gdev);
541 return ret;
542 }
543
gpiochip_machine_hog(struct gpio_chip * gc,struct gpiod_hog * hog)544 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
545 {
546 struct gpio_desc *desc;
547 int rv;
548
549 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
550 if (IS_ERR(desc)) {
551 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
552 PTR_ERR(desc));
553 return;
554 }
555
556 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
557 return;
558
559 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
560 if (rv)
561 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
562 __func__, gc->label, hog->chip_hwnum, rv);
563 }
564
machine_gpiochip_add(struct gpio_chip * gc)565 static void machine_gpiochip_add(struct gpio_chip *gc)
566 {
567 struct gpiod_hog *hog;
568
569 mutex_lock(&gpio_machine_hogs_mutex);
570
571 list_for_each_entry(hog, &gpio_machine_hogs, list) {
572 if (!strcmp(gc->label, hog->chip_label))
573 gpiochip_machine_hog(gc, hog);
574 }
575
576 mutex_unlock(&gpio_machine_hogs_mutex);
577 }
578
gpiochip_setup_devs(void)579 static void gpiochip_setup_devs(void)
580 {
581 struct gpio_device *gdev;
582 int ret;
583
584 list_for_each_entry(gdev, &gpio_devices, list) {
585 ret = gpiochip_setup_dev(gdev);
586 if (ret)
587 dev_err(&gdev->dev,
588 "Failed to initialize gpio device (%d)\n", ret);
589 }
590 }
591
gpiochip_add_data_with_key(struct gpio_chip * gc,void * data,struct lock_class_key * lock_key,struct lock_class_key * request_key)592 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
593 struct lock_class_key *lock_key,
594 struct lock_class_key *request_key)
595 {
596 struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
597 struct gpio_device *gdev;
598 unsigned long flags;
599 unsigned int i;
600 u32 ngpios = 0;
601 int base = 0;
602 int ret = 0;
603
604 /*
605 * First: allocate and populate the internal stat container, and
606 * set up the struct device.
607 */
608 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
609 if (!gdev)
610 return -ENOMEM;
611 gdev->dev.bus = &gpio_bus_type;
612 gdev->dev.parent = gc->parent;
613 gdev->chip = gc;
614 gc->gpiodev = gdev;
615
616 of_gpio_dev_init(gc, gdev);
617 acpi_gpio_dev_init(gc, gdev);
618
619 /*
620 * Assign fwnode depending on the result of the previous calls,
621 * if none of them succeed, assign it to the parent's one.
622 */
623 gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
624
625 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
626 if (gdev->id < 0) {
627 ret = gdev->id;
628 goto err_free_gdev;
629 }
630
631 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
632 if (ret)
633 goto err_free_ida;
634
635 device_initialize(&gdev->dev);
636 if (gc->parent && gc->parent->driver)
637 gdev->owner = gc->parent->driver->owner;
638 else if (gc->owner)
639 /* TODO: remove chip->owner */
640 gdev->owner = gc->owner;
641 else
642 gdev->owner = THIS_MODULE;
643
644 /*
645 * Try the device properties if the driver didn't supply the number
646 * of GPIO lines.
647 */
648 ngpios = gc->ngpio;
649 if (ngpios == 0) {
650 ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);
651 if (ret == -ENODATA)
652 /*
653 * -ENODATA means that there is no property found and
654 * we want to issue the error message to the user.
655 * Besides that, we want to return different error code
656 * to state that supplied value is not valid.
657 */
658 ngpios = 0;
659 else if (ret)
660 goto err_free_dev_name;
661
662 gc->ngpio = ngpios;
663 }
664
665 if (gc->ngpio == 0) {
666 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
667 ret = -EINVAL;
668 goto err_free_dev_name;
669 }
670
671 if (gc->ngpio > FASTPATH_NGPIO)
672 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
673 gc->ngpio, FASTPATH_NGPIO);
674
675 gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
676 if (!gdev->descs) {
677 ret = -ENOMEM;
678 goto err_free_dev_name;
679 }
680
681 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
682 if (!gdev->label) {
683 ret = -ENOMEM;
684 goto err_free_descs;
685 }
686
687 gdev->ngpio = gc->ngpio;
688 gdev->data = data;
689
690 spin_lock_irqsave(&gpio_lock, flags);
691
692 /*
693 * TODO: this allocates a Linux GPIO number base in the global
694 * GPIO numberspace for this chip. In the long run we want to
695 * get *rid* of this numberspace and use only descriptors, but
696 * it may be a pipe dream. It will not happen before we get rid
697 * of the sysfs interface anyways.
698 */
699 base = gc->base;
700 if (base < 0) {
701 base = gpiochip_find_base(gc->ngpio);
702 if (base < 0) {
703 spin_unlock_irqrestore(&gpio_lock, flags);
704 ret = base;
705 base = 0;
706 goto err_free_label;
707 }
708 /*
709 * TODO: it should not be necessary to reflect the assigned
710 * base outside of the GPIO subsystem. Go over drivers and
711 * see if anyone makes use of this, else drop this and assign
712 * a poison instead.
713 */
714 gc->base = base;
715 }
716 gdev->base = base;
717
718 ret = gpiodev_add_to_list(gdev);
719 if (ret) {
720 spin_unlock_irqrestore(&gpio_lock, flags);
721 goto err_free_label;
722 }
723
724 for (i = 0; i < gc->ngpio; i++)
725 gdev->descs[i].gdev = gdev;
726
727 spin_unlock_irqrestore(&gpio_lock, flags);
728
729 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
730
731 #ifdef CONFIG_PINCTRL
732 INIT_LIST_HEAD(&gdev->pin_ranges);
733 #endif
734
735 if (gc->names)
736 ret = gpiochip_set_desc_names(gc);
737 else
738 ret = devprop_gpiochip_set_names(gc);
739 if (ret)
740 goto err_remove_from_list;
741
742 ret = gpiochip_alloc_valid_mask(gc);
743 if (ret)
744 goto err_remove_from_list;
745
746 ret = of_gpiochip_add(gc);
747 if (ret)
748 goto err_free_gpiochip_mask;
749
750 ret = gpiochip_init_valid_mask(gc);
751 if (ret)
752 goto err_remove_of_chip;
753
754 for (i = 0; i < gc->ngpio; i++) {
755 struct gpio_desc *desc = &gdev->descs[i];
756
757 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
758 assign_bit(FLAG_IS_OUT,
759 &desc->flags, !gc->get_direction(gc, i));
760 } else {
761 assign_bit(FLAG_IS_OUT,
762 &desc->flags, !gc->direction_input);
763 }
764 }
765
766 ret = gpiochip_add_pin_ranges(gc);
767 if (ret)
768 goto err_remove_of_chip;
769
770 acpi_gpiochip_add(gc);
771
772 machine_gpiochip_add(gc);
773
774 ret = gpiochip_irqchip_init_valid_mask(gc);
775 if (ret)
776 goto err_remove_acpi_chip;
777
778 ret = gpiochip_irqchip_init_hw(gc);
779 if (ret)
780 goto err_remove_acpi_chip;
781
782 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
783 if (ret)
784 goto err_remove_irqchip_mask;
785
786 /*
787 * By first adding the chardev, and then adding the device,
788 * we get a device node entry in sysfs under
789 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
790 * coldplug of device nodes and other udev business.
791 * We can do this only if gpiolib has been initialized.
792 * Otherwise, defer until later.
793 */
794 if (gpiolib_initialized) {
795 ret = gpiochip_setup_dev(gdev);
796 if (ret)
797 goto err_remove_irqchip;
798 }
799 return 0;
800
801 err_remove_irqchip:
802 gpiochip_irqchip_remove(gc);
803 err_remove_irqchip_mask:
804 gpiochip_irqchip_free_valid_mask(gc);
805 err_remove_acpi_chip:
806 acpi_gpiochip_remove(gc);
807 err_remove_of_chip:
808 gpiochip_free_hogs(gc);
809 of_gpiochip_remove(gc);
810 err_free_gpiochip_mask:
811 gpiochip_remove_pin_ranges(gc);
812 gpiochip_free_valid_mask(gc);
813 if (gdev->dev.release) {
814 /* release() has been registered by gpiochip_setup_dev() */
815 put_device(&gdev->dev);
816 goto err_print_message;
817 }
818 err_remove_from_list:
819 spin_lock_irqsave(&gpio_lock, flags);
820 list_del(&gdev->list);
821 spin_unlock_irqrestore(&gpio_lock, flags);
822 err_free_label:
823 kfree_const(gdev->label);
824 err_free_descs:
825 kfree(gdev->descs);
826 err_free_dev_name:
827 kfree(dev_name(&gdev->dev));
828 err_free_ida:
829 ida_free(&gpio_ida, gdev->id);
830 err_free_gdev:
831 kfree(gdev);
832 err_print_message:
833 /* failures here can mean systems won't boot... */
834 if (ret != -EPROBE_DEFER) {
835 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
836 base, base + (int)ngpios - 1,
837 gc->label ? : "generic", ret);
838 }
839 return ret;
840 }
841 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
842
843 /**
844 * gpiochip_get_data() - get per-subdriver data for the chip
845 * @gc: GPIO chip
846 *
847 * Returns:
848 * The per-subdriver data for the chip.
849 */
gpiochip_get_data(struct gpio_chip * gc)850 void *gpiochip_get_data(struct gpio_chip *gc)
851 {
852 return gc->gpiodev->data;
853 }
854 EXPORT_SYMBOL_GPL(gpiochip_get_data);
855
856 /**
857 * gpiochip_remove() - unregister a gpio_chip
858 * @gc: the chip to unregister
859 *
860 * A gpio_chip with any GPIOs still requested may not be removed.
861 */
gpiochip_remove(struct gpio_chip * gc)862 void gpiochip_remove(struct gpio_chip *gc)
863 {
864 struct gpio_device *gdev = gc->gpiodev;
865 unsigned long flags;
866 unsigned int i;
867
868 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
869 gpiochip_sysfs_unregister(gdev);
870 gpiochip_free_hogs(gc);
871 /* Numb the device, cancelling all outstanding operations */
872 gdev->chip = NULL;
873 gpiochip_irqchip_remove(gc);
874 acpi_gpiochip_remove(gc);
875 of_gpiochip_remove(gc);
876 gpiochip_remove_pin_ranges(gc);
877 gpiochip_free_valid_mask(gc);
878 /*
879 * We accept no more calls into the driver from this point, so
880 * NULL the driver data pointer
881 */
882 gdev->data = NULL;
883
884 spin_lock_irqsave(&gpio_lock, flags);
885 for (i = 0; i < gdev->ngpio; i++) {
886 if (gpiochip_is_requested(gc, i))
887 break;
888 }
889 spin_unlock_irqrestore(&gpio_lock, flags);
890
891 if (i != gdev->ngpio)
892 dev_crit(&gdev->dev,
893 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
894
895 /*
896 * The gpiochip side puts its use of the device to rest here:
897 * if there are no userspace clients, the chardev and device will
898 * be removed, else it will be dangling until the last user is
899 * gone.
900 */
901 gcdev_unregister(gdev);
902 put_device(&gdev->dev);
903 }
904 EXPORT_SYMBOL_GPL(gpiochip_remove);
905
906 /**
907 * gpiochip_find() - iterator for locating a specific gpio_chip
908 * @data: data to pass to match function
909 * @match: Callback function to check gpio_chip
910 *
911 * Similar to bus_find_device. It returns a reference to a gpio_chip as
912 * determined by a user supplied @match callback. The callback should return
913 * 0 if the device doesn't match and non-zero if it does. If the callback is
914 * non-zero, this function will return to the caller and not iterate over any
915 * more gpio_chips.
916 */
gpiochip_find(void * data,int (* match)(struct gpio_chip * gc,void * data))917 struct gpio_chip *gpiochip_find(void *data,
918 int (*match)(struct gpio_chip *gc,
919 void *data))
920 {
921 struct gpio_device *gdev;
922 struct gpio_chip *gc = NULL;
923 unsigned long flags;
924
925 spin_lock_irqsave(&gpio_lock, flags);
926 list_for_each_entry(gdev, &gpio_devices, list)
927 if (gdev->chip && match(gdev->chip, data)) {
928 gc = gdev->chip;
929 break;
930 }
931
932 spin_unlock_irqrestore(&gpio_lock, flags);
933
934 return gc;
935 }
936 EXPORT_SYMBOL_GPL(gpiochip_find);
937
gpiochip_match_name(struct gpio_chip * gc,void * data)938 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
939 {
940 const char *name = data;
941
942 return !strcmp(gc->label, name);
943 }
944
find_chip_by_name(const char * name)945 static struct gpio_chip *find_chip_by_name(const char *name)
946 {
947 return gpiochip_find((void *)name, gpiochip_match_name);
948 }
949
950 #ifdef CONFIG_GPIOLIB_IRQCHIP
951
952 /*
953 * The following is irqchip helper code for gpiochips.
954 */
955
gpiochip_irqchip_init_hw(struct gpio_chip * gc)956 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
957 {
958 struct gpio_irq_chip *girq = &gc->irq;
959
960 if (!girq->init_hw)
961 return 0;
962
963 return girq->init_hw(gc);
964 }
965
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)966 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
967 {
968 struct gpio_irq_chip *girq = &gc->irq;
969
970 if (!girq->init_valid_mask)
971 return 0;
972
973 girq->valid_mask = gpiochip_allocate_mask(gc);
974 if (!girq->valid_mask)
975 return -ENOMEM;
976
977 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
978
979 return 0;
980 }
981
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)982 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
983 {
984 bitmap_free(gc->irq.valid_mask);
985 gc->irq.valid_mask = NULL;
986 }
987
gpiochip_irqchip_irq_valid(const struct gpio_chip * gc,unsigned int offset)988 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
989 unsigned int offset)
990 {
991 if (!gpiochip_line_is_valid(gc, offset))
992 return false;
993 /* No mask means all valid */
994 if (likely(!gc->irq.valid_mask))
995 return true;
996 return test_bit(offset, gc->irq.valid_mask);
997 }
998 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
999
1000 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1001
1002 /**
1003 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1004 * to a gpiochip
1005 * @gc: the gpiochip to set the irqchip hierarchical handler to
1006 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1007 * will then percolate up to the parent
1008 */
gpiochip_set_hierarchical_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip)1009 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1010 struct irq_chip *irqchip)
1011 {
1012 /* DT will deal with mapping each IRQ as we go along */
1013 if (is_of_node(gc->irq.fwnode))
1014 return;
1015
1016 /*
1017 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1018 * irqs upfront instead of dynamically since we don't have the
1019 * dynamic type of allocation that hardware description languages
1020 * provide. Once all GPIO drivers using board files are gone from
1021 * the kernel we can delete this code, but for a transitional period
1022 * it is necessary to keep this around.
1023 */
1024 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1025 int i;
1026 int ret;
1027
1028 for (i = 0; i < gc->ngpio; i++) {
1029 struct irq_fwspec fwspec;
1030 unsigned int parent_hwirq;
1031 unsigned int parent_type;
1032 struct gpio_irq_chip *girq = &gc->irq;
1033
1034 /*
1035 * We call the child to parent translation function
1036 * only to check if the child IRQ is valid or not.
1037 * Just pick the rising edge type here as that is what
1038 * we likely need to support.
1039 */
1040 ret = girq->child_to_parent_hwirq(gc, i,
1041 IRQ_TYPE_EDGE_RISING,
1042 &parent_hwirq,
1043 &parent_type);
1044 if (ret) {
1045 chip_err(gc, "skip set-up on hwirq %d\n",
1046 i);
1047 continue;
1048 }
1049
1050 fwspec.fwnode = gc->irq.fwnode;
1051 /* This is the hwirq for the GPIO line side of things */
1052 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1053 /* Just pick something */
1054 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1055 fwspec.param_count = 2;
1056 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1057 /* just pick something */
1058 -1,
1059 1,
1060 NUMA_NO_NODE,
1061 &fwspec,
1062 false,
1063 NULL);
1064 if (ret < 0) {
1065 chip_err(gc,
1066 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1067 i, parent_hwirq,
1068 ret);
1069 }
1070 }
1071 }
1072
1073 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1074
1075 return;
1076 }
1077
gpiochip_hierarchy_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1078 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1079 struct irq_fwspec *fwspec,
1080 unsigned long *hwirq,
1081 unsigned int *type)
1082 {
1083 /* We support standard DT translation */
1084 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1085 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1086 }
1087
1088 /* This is for board files and others not using DT */
1089 if (is_fwnode_irqchip(fwspec->fwnode)) {
1090 int ret;
1091
1092 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1093 if (ret)
1094 return ret;
1095 WARN_ON(*type == IRQ_TYPE_NONE);
1096 return 0;
1097 }
1098 return -EINVAL;
1099 }
1100
gpiochip_hierarchy_irq_domain_alloc(struct irq_domain * d,unsigned int irq,unsigned int nr_irqs,void * data)1101 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1102 unsigned int irq,
1103 unsigned int nr_irqs,
1104 void *data)
1105 {
1106 struct gpio_chip *gc = d->host_data;
1107 irq_hw_number_t hwirq;
1108 unsigned int type = IRQ_TYPE_NONE;
1109 struct irq_fwspec *fwspec = data;
1110 void *parent_arg;
1111 unsigned int parent_hwirq;
1112 unsigned int parent_type;
1113 struct gpio_irq_chip *girq = &gc->irq;
1114 int ret;
1115
1116 /*
1117 * The nr_irqs parameter is always one except for PCI multi-MSI
1118 * so this should not happen.
1119 */
1120 WARN_ON(nr_irqs != 1);
1121
1122 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1123 if (ret)
1124 return ret;
1125
1126 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1127
1128 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1129 &parent_hwirq, &parent_type);
1130 if (ret) {
1131 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1132 return ret;
1133 }
1134 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1135
1136 /*
1137 * We set handle_bad_irq because the .set_type() should
1138 * always be invoked and set the right type of handler.
1139 */
1140 irq_domain_set_info(d,
1141 irq,
1142 hwirq,
1143 gc->irq.chip,
1144 gc,
1145 girq->handler,
1146 NULL, NULL);
1147 irq_set_probe(irq);
1148
1149 /* This parent only handles asserted level IRQs */
1150 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1151 if (!parent_arg)
1152 return -ENOMEM;
1153
1154 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1155 irq, parent_hwirq);
1156 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1157 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1158 /*
1159 * If the parent irqdomain is msi, the interrupts have already
1160 * been allocated, so the EEXIST is good.
1161 */
1162 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1163 ret = 0;
1164 if (ret)
1165 chip_err(gc,
1166 "failed to allocate parent hwirq %d for hwirq %lu\n",
1167 parent_hwirq, hwirq);
1168
1169 kfree(parent_arg);
1170 return ret;
1171 }
1172
gpiochip_child_offset_to_irq_noop(struct gpio_chip * gc,unsigned int offset)1173 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1174 unsigned int offset)
1175 {
1176 return offset;
1177 }
1178
gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops * ops)1179 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1180 {
1181 ops->activate = gpiochip_irq_domain_activate;
1182 ops->deactivate = gpiochip_irq_domain_deactivate;
1183 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1184 ops->free = irq_domain_free_irqs_common;
1185
1186 /*
1187 * We only allow overriding the translate() function for
1188 * hierarchical chips, and this should only be done if the user
1189 * really need something other than 1:1 translation.
1190 */
1191 if (!ops->translate)
1192 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1193 }
1194
gpiochip_hierarchy_add_domain(struct gpio_chip * gc)1195 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1196 {
1197 if (!gc->irq.child_to_parent_hwirq ||
1198 !gc->irq.fwnode) {
1199 chip_err(gc, "missing irqdomain vital data\n");
1200 return -EINVAL;
1201 }
1202
1203 if (!gc->irq.child_offset_to_irq)
1204 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1205
1206 if (!gc->irq.populate_parent_alloc_arg)
1207 gc->irq.populate_parent_alloc_arg =
1208 gpiochip_populate_parent_fwspec_twocell;
1209
1210 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1211
1212 gc->irq.domain = irq_domain_create_hierarchy(
1213 gc->irq.parent_domain,
1214 0,
1215 gc->ngpio,
1216 gc->irq.fwnode,
1217 &gc->irq.child_irq_domain_ops,
1218 gc);
1219
1220 if (!gc->irq.domain)
1221 return -ENOMEM;
1222
1223 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1224
1225 return 0;
1226 }
1227
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1228 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1229 {
1230 return !!gc->irq.parent_domain;
1231 }
1232
gpiochip_populate_parent_fwspec_twocell(struct gpio_chip * gc,unsigned int parent_hwirq,unsigned int parent_type)1233 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1234 unsigned int parent_hwirq,
1235 unsigned int parent_type)
1236 {
1237 struct irq_fwspec *fwspec;
1238
1239 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1240 if (!fwspec)
1241 return NULL;
1242
1243 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1244 fwspec->param_count = 2;
1245 fwspec->param[0] = parent_hwirq;
1246 fwspec->param[1] = parent_type;
1247
1248 return fwspec;
1249 }
1250 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1251
gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip * gc,unsigned int parent_hwirq,unsigned int parent_type)1252 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1253 unsigned int parent_hwirq,
1254 unsigned int parent_type)
1255 {
1256 struct irq_fwspec *fwspec;
1257
1258 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1259 if (!fwspec)
1260 return NULL;
1261
1262 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1263 fwspec->param_count = 4;
1264 fwspec->param[0] = 0;
1265 fwspec->param[1] = parent_hwirq;
1266 fwspec->param[2] = 0;
1267 fwspec->param[3] = parent_type;
1268
1269 return fwspec;
1270 }
1271 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1272
1273 #else
1274
gpiochip_hierarchy_add_domain(struct gpio_chip * gc)1275 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1276 {
1277 return -EINVAL;
1278 }
1279
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1280 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1281 {
1282 return false;
1283 }
1284
1285 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1286
1287 /**
1288 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1289 * @d: the irqdomain used by this irqchip
1290 * @irq: the global irq number used by this GPIO irqchip irq
1291 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1292 *
1293 * This function will set up the mapping for a certain IRQ line on a
1294 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1295 * stored inside the gpiochip.
1296 */
gpiochip_irq_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)1297 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1298 irq_hw_number_t hwirq)
1299 {
1300 struct gpio_chip *gc = d->host_data;
1301 int ret = 0;
1302
1303 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1304 return -ENXIO;
1305
1306 irq_set_chip_data(irq, gc);
1307 /*
1308 * This lock class tells lockdep that GPIO irqs are in a different
1309 * category than their parents, so it won't report false recursion.
1310 */
1311 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1312 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1313 /* Chips that use nested thread handlers have them marked */
1314 if (gc->irq.threaded)
1315 irq_set_nested_thread(irq, 1);
1316 irq_set_noprobe(irq);
1317
1318 if (gc->irq.num_parents == 1)
1319 ret = irq_set_parent(irq, gc->irq.parents[0]);
1320 else if (gc->irq.map)
1321 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1322
1323 if (ret < 0)
1324 return ret;
1325
1326 /*
1327 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1328 * is passed as default type.
1329 */
1330 if (gc->irq.default_type != IRQ_TYPE_NONE)
1331 irq_set_irq_type(irq, gc->irq.default_type);
1332
1333 return 0;
1334 }
1335 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1336
gpiochip_irq_unmap(struct irq_domain * d,unsigned int irq)1337 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1338 {
1339 struct gpio_chip *gc = d->host_data;
1340
1341 if (gc->irq.threaded)
1342 irq_set_nested_thread(irq, 0);
1343 irq_set_chip_and_handler(irq, NULL, NULL);
1344 irq_set_chip_data(irq, NULL);
1345 }
1346 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1347
1348 static const struct irq_domain_ops gpiochip_domain_ops = {
1349 .map = gpiochip_irq_map,
1350 .unmap = gpiochip_irq_unmap,
1351 /* Virtually all GPIO irqchips are twocell:ed */
1352 .xlate = irq_domain_xlate_twocell,
1353 };
1354
1355 /*
1356 * TODO: move these activate/deactivate in under the hierarchicial
1357 * irqchip implementation as static once SPMI and SSBI (all external
1358 * users) are phased over.
1359 */
1360 /**
1361 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1362 * @domain: The IRQ domain used by this IRQ chip
1363 * @data: Outermost irq_data associated with the IRQ
1364 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1365 *
1366 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1367 * used as the activate function for the &struct irq_domain_ops. The host_data
1368 * for the IRQ domain must be the &struct gpio_chip.
1369 */
gpiochip_irq_domain_activate(struct irq_domain * domain,struct irq_data * data,bool reserve)1370 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1371 struct irq_data *data, bool reserve)
1372 {
1373 struct gpio_chip *gc = domain->host_data;
1374
1375 return gpiochip_lock_as_irq(gc, data->hwirq);
1376 }
1377 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1378
1379 /**
1380 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1381 * @domain: The IRQ domain used by this IRQ chip
1382 * @data: Outermost irq_data associated with the IRQ
1383 *
1384 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1385 * be used as the deactivate function for the &struct irq_domain_ops. The
1386 * host_data for the IRQ domain must be the &struct gpio_chip.
1387 */
gpiochip_irq_domain_deactivate(struct irq_domain * domain,struct irq_data * data)1388 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1389 struct irq_data *data)
1390 {
1391 struct gpio_chip *gc = domain->host_data;
1392
1393 return gpiochip_unlock_as_irq(gc, data->hwirq);
1394 }
1395 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1396
gpiochip_to_irq(struct gpio_chip * gc,unsigned int offset)1397 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1398 {
1399 struct irq_domain *domain = gc->irq.domain;
1400
1401 #ifdef CONFIG_GPIOLIB_IRQCHIP
1402 /*
1403 * Avoid race condition with other code, which tries to lookup
1404 * an IRQ before the irqchip has been properly registered,
1405 * i.e. while gpiochip is still being brought up.
1406 */
1407 if (!gc->irq.initialized)
1408 return -EPROBE_DEFER;
1409 #endif
1410
1411 if (!gpiochip_irqchip_irq_valid(gc, offset))
1412 return -ENXIO;
1413
1414 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1415 if (irq_domain_is_hierarchy(domain)) {
1416 struct irq_fwspec spec;
1417
1418 spec.fwnode = domain->fwnode;
1419 spec.param_count = 2;
1420 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1421 spec.param[1] = IRQ_TYPE_NONE;
1422
1423 return irq_create_fwspec_mapping(&spec);
1424 }
1425 #endif
1426
1427 return irq_create_mapping(domain, offset);
1428 }
1429
gpiochip_irq_reqres(struct irq_data * d)1430 static int gpiochip_irq_reqres(struct irq_data *d)
1431 {
1432 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1433
1434 return gpiochip_reqres_irq(gc, d->hwirq);
1435 }
1436
gpiochip_irq_relres(struct irq_data * d)1437 static void gpiochip_irq_relres(struct irq_data *d)
1438 {
1439 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1440
1441 gpiochip_relres_irq(gc, d->hwirq);
1442 }
1443
gpiochip_irq_mask(struct irq_data * d)1444 static void gpiochip_irq_mask(struct irq_data *d)
1445 {
1446 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1447
1448 if (gc->irq.irq_mask)
1449 gc->irq.irq_mask(d);
1450 gpiochip_disable_irq(gc, d->hwirq);
1451 }
1452
gpiochip_irq_unmask(struct irq_data * d)1453 static void gpiochip_irq_unmask(struct irq_data *d)
1454 {
1455 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1456
1457 gpiochip_enable_irq(gc, d->hwirq);
1458 if (gc->irq.irq_unmask)
1459 gc->irq.irq_unmask(d);
1460 }
1461
gpiochip_irq_enable(struct irq_data * d)1462 static void gpiochip_irq_enable(struct irq_data *d)
1463 {
1464 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1465
1466 gpiochip_enable_irq(gc, d->hwirq);
1467 gc->irq.irq_enable(d);
1468 }
1469
gpiochip_irq_disable(struct irq_data * d)1470 static void gpiochip_irq_disable(struct irq_data *d)
1471 {
1472 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1473
1474 gc->irq.irq_disable(d);
1475 gpiochip_disable_irq(gc, d->hwirq);
1476 }
1477
gpiochip_set_irq_hooks(struct gpio_chip * gc)1478 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1479 {
1480 struct irq_chip *irqchip = gc->irq.chip;
1481
1482 if (!irqchip->irq_request_resources &&
1483 !irqchip->irq_release_resources) {
1484 irqchip->irq_request_resources = gpiochip_irq_reqres;
1485 irqchip->irq_release_resources = gpiochip_irq_relres;
1486 }
1487 if (WARN_ON(gc->irq.irq_enable))
1488 return;
1489 /* Check if the irqchip already has this hook... */
1490 if (irqchip->irq_enable == gpiochip_irq_enable ||
1491 irqchip->irq_mask == gpiochip_irq_mask) {
1492 /*
1493 * ...and if so, give a gentle warning that this is bad
1494 * practice.
1495 */
1496 chip_info(gc,
1497 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1498 return;
1499 }
1500
1501 if (irqchip->irq_disable) {
1502 gc->irq.irq_disable = irqchip->irq_disable;
1503 irqchip->irq_disable = gpiochip_irq_disable;
1504 } else {
1505 gc->irq.irq_mask = irqchip->irq_mask;
1506 irqchip->irq_mask = gpiochip_irq_mask;
1507 }
1508
1509 if (irqchip->irq_enable) {
1510 gc->irq.irq_enable = irqchip->irq_enable;
1511 irqchip->irq_enable = gpiochip_irq_enable;
1512 } else {
1513 gc->irq.irq_unmask = irqchip->irq_unmask;
1514 irqchip->irq_unmask = gpiochip_irq_unmask;
1515 }
1516 }
1517
1518 /**
1519 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1520 * @gc: the GPIO chip to add the IRQ chip to
1521 * @lock_key: lockdep class for IRQ lock
1522 * @request_key: lockdep class for IRQ request
1523 */
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)1524 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1525 struct lock_class_key *lock_key,
1526 struct lock_class_key *request_key)
1527 {
1528 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1529 struct irq_chip *irqchip = gc->irq.chip;
1530 unsigned int type;
1531 unsigned int i;
1532
1533 if (!irqchip)
1534 return 0;
1535
1536 if (gc->irq.parent_handler && gc->can_sleep) {
1537 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1538 return -EINVAL;
1539 }
1540
1541 type = gc->irq.default_type;
1542
1543 /*
1544 * Specifying a default trigger is a terrible idea if DT or ACPI is
1545 * used to configure the interrupts, as you may end up with
1546 * conflicting triggers. Tell the user, and reset to NONE.
1547 */
1548 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1549 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1550 type = IRQ_TYPE_NONE;
1551
1552 if (gc->to_irq)
1553 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1554
1555 gc->to_irq = gpiochip_to_irq;
1556 gc->irq.default_type = type;
1557 gc->irq.lock_key = lock_key;
1558 gc->irq.request_key = request_key;
1559
1560 /* If a parent irqdomain is provided, let's build a hierarchy */
1561 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1562 int ret = gpiochip_hierarchy_add_domain(gc);
1563 if (ret)
1564 return ret;
1565 } else {
1566 /* Some drivers provide custom irqdomain ops */
1567 gc->irq.domain = irq_domain_create_simple(fwnode,
1568 gc->ngpio,
1569 gc->irq.first,
1570 gc->irq.domain_ops ?: &gpiochip_domain_ops,
1571 gc);
1572 if (!gc->irq.domain)
1573 return -EINVAL;
1574 }
1575
1576 if (gc->irq.parent_handler) {
1577 void *data = gc->irq.parent_handler_data ?: gc;
1578
1579 for (i = 0; i < gc->irq.num_parents; i++) {
1580 /*
1581 * The parent IRQ chip is already using the chip_data
1582 * for this IRQ chip, so our callbacks simply use the
1583 * handler_data.
1584 */
1585 irq_set_chained_handler_and_data(gc->irq.parents[i],
1586 gc->irq.parent_handler,
1587 data);
1588 }
1589 }
1590
1591 gpiochip_set_irq_hooks(gc);
1592
1593 /*
1594 * Using barrier() here to prevent compiler from reordering
1595 * gc->irq.initialized before initialization of above
1596 * GPIO chip irq members.
1597 */
1598 barrier();
1599
1600 gc->irq.initialized = true;
1601
1602 acpi_gpiochip_request_interrupts(gc);
1603
1604 return 0;
1605 }
1606
1607 /**
1608 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1609 * @gc: the gpiochip to remove the irqchip from
1610 *
1611 * This is called only from gpiochip_remove()
1612 */
gpiochip_irqchip_remove(struct gpio_chip * gc)1613 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1614 {
1615 struct irq_chip *irqchip = gc->irq.chip;
1616 unsigned int offset;
1617
1618 acpi_gpiochip_free_interrupts(gc);
1619
1620 if (irqchip && gc->irq.parent_handler) {
1621 struct gpio_irq_chip *irq = &gc->irq;
1622 unsigned int i;
1623
1624 for (i = 0; i < irq->num_parents; i++)
1625 irq_set_chained_handler_and_data(irq->parents[i],
1626 NULL, NULL);
1627 }
1628
1629 /* Remove all IRQ mappings and delete the domain */
1630 if (gc->irq.domain) {
1631 unsigned int irq;
1632
1633 for (offset = 0; offset < gc->ngpio; offset++) {
1634 if (!gpiochip_irqchip_irq_valid(gc, offset))
1635 continue;
1636
1637 irq = irq_find_mapping(gc->irq.domain, offset);
1638 irq_dispose_mapping(irq);
1639 }
1640
1641 irq_domain_remove(gc->irq.domain);
1642 }
1643
1644 if (irqchip) {
1645 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1646 irqchip->irq_request_resources = NULL;
1647 irqchip->irq_release_resources = NULL;
1648 }
1649 if (irqchip->irq_enable == gpiochip_irq_enable) {
1650 irqchip->irq_enable = gc->irq.irq_enable;
1651 irqchip->irq_disable = gc->irq.irq_disable;
1652 }
1653 }
1654 gc->irq.irq_enable = NULL;
1655 gc->irq.irq_disable = NULL;
1656 gc->irq.chip = NULL;
1657
1658 gpiochip_irqchip_free_valid_mask(gc);
1659 }
1660
1661 /**
1662 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1663 * @gc: the gpiochip to add the irqchip to
1664 * @domain: the irqdomain to add to the gpiochip
1665 *
1666 * This function adds an IRQ domain to the gpiochip.
1667 */
gpiochip_irqchip_add_domain(struct gpio_chip * gc,struct irq_domain * domain)1668 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1669 struct irq_domain *domain)
1670 {
1671 if (!domain)
1672 return -EINVAL;
1673
1674 gc->to_irq = gpiochip_to_irq;
1675 gc->irq.domain = domain;
1676
1677 return 0;
1678 }
1679 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1680
1681 #else /* CONFIG_GPIOLIB_IRQCHIP */
1682
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)1683 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1684 struct lock_class_key *lock_key,
1685 struct lock_class_key *request_key)
1686 {
1687 return 0;
1688 }
gpiochip_irqchip_remove(struct gpio_chip * gc)1689 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1690
gpiochip_irqchip_init_hw(struct gpio_chip * gc)1691 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1692 {
1693 return 0;
1694 }
1695
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)1696 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1697 {
1698 return 0;
1699 }
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)1700 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1701 { }
1702
1703 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1704
1705 /**
1706 * gpiochip_generic_request() - request the gpio function for a pin
1707 * @gc: the gpiochip owning the GPIO
1708 * @offset: the offset of the GPIO to request for GPIO function
1709 */
gpiochip_generic_request(struct gpio_chip * gc,unsigned int offset)1710 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
1711 {
1712 #ifdef CONFIG_PINCTRL
1713 if (list_empty(&gc->gpiodev->pin_ranges))
1714 return 0;
1715 #endif
1716
1717 return pinctrl_gpio_request(gc->gpiodev->base + offset);
1718 }
1719 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1720
1721 /**
1722 * gpiochip_generic_free() - free the gpio function from a pin
1723 * @gc: the gpiochip to request the gpio function for
1724 * @offset: the offset of the GPIO to free from GPIO function
1725 */
gpiochip_generic_free(struct gpio_chip * gc,unsigned int offset)1726 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
1727 {
1728 #ifdef CONFIG_PINCTRL
1729 if (list_empty(&gc->gpiodev->pin_ranges))
1730 return;
1731 #endif
1732
1733 pinctrl_gpio_free(gc->gpiodev->base + offset);
1734 }
1735 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1736
1737 /**
1738 * gpiochip_generic_config() - apply configuration for a pin
1739 * @gc: the gpiochip owning the GPIO
1740 * @offset: the offset of the GPIO to apply the configuration
1741 * @config: the configuration to be applied
1742 */
gpiochip_generic_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)1743 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
1744 unsigned long config)
1745 {
1746 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1747 }
1748 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1749
1750 #ifdef CONFIG_PINCTRL
1751
1752 /**
1753 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1754 * @gc: the gpiochip to add the range for
1755 * @pctldev: the pin controller to map to
1756 * @gpio_offset: the start offset in the current gpio_chip number space
1757 * @pin_group: name of the pin group inside the pin controller
1758 *
1759 * Calling this function directly from a DeviceTree-supported
1760 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1761 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1762 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1763 */
gpiochip_add_pingroup_range(struct gpio_chip * gc,struct pinctrl_dev * pctldev,unsigned int gpio_offset,const char * pin_group)1764 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1765 struct pinctrl_dev *pctldev,
1766 unsigned int gpio_offset, const char *pin_group)
1767 {
1768 struct gpio_pin_range *pin_range;
1769 struct gpio_device *gdev = gc->gpiodev;
1770 int ret;
1771
1772 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1773 if (!pin_range) {
1774 chip_err(gc, "failed to allocate pin ranges\n");
1775 return -ENOMEM;
1776 }
1777
1778 /* Use local offset as range ID */
1779 pin_range->range.id = gpio_offset;
1780 pin_range->range.gc = gc;
1781 pin_range->range.name = gc->label;
1782 pin_range->range.base = gdev->base + gpio_offset;
1783 pin_range->pctldev = pctldev;
1784
1785 ret = pinctrl_get_group_pins(pctldev, pin_group,
1786 &pin_range->range.pins,
1787 &pin_range->range.npins);
1788 if (ret < 0) {
1789 kfree(pin_range);
1790 return ret;
1791 }
1792
1793 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1794
1795 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1796 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1797 pinctrl_dev_get_devname(pctldev), pin_group);
1798
1799 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1800
1801 return 0;
1802 }
1803 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1804
1805 /**
1806 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1807 * @gc: the gpiochip to add the range for
1808 * @pinctl_name: the dev_name() of the pin controller to map to
1809 * @gpio_offset: the start offset in the current gpio_chip number space
1810 * @pin_offset: the start offset in the pin controller number space
1811 * @npins: the number of pins from the offset of each pin space (GPIO and
1812 * pin controller) to accumulate in this range
1813 *
1814 * Returns:
1815 * 0 on success, or a negative error-code on failure.
1816 *
1817 * Calling this function directly from a DeviceTree-supported
1818 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1819 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1820 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1821 */
gpiochip_add_pin_range(struct gpio_chip * gc,const char * pinctl_name,unsigned int gpio_offset,unsigned int pin_offset,unsigned int npins)1822 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1823 unsigned int gpio_offset, unsigned int pin_offset,
1824 unsigned int npins)
1825 {
1826 struct gpio_pin_range *pin_range;
1827 struct gpio_device *gdev = gc->gpiodev;
1828 int ret;
1829
1830 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1831 if (!pin_range) {
1832 chip_err(gc, "failed to allocate pin ranges\n");
1833 return -ENOMEM;
1834 }
1835
1836 /* Use local offset as range ID */
1837 pin_range->range.id = gpio_offset;
1838 pin_range->range.gc = gc;
1839 pin_range->range.name = gc->label;
1840 pin_range->range.base = gdev->base + gpio_offset;
1841 pin_range->range.pin_base = pin_offset;
1842 pin_range->range.npins = npins;
1843 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1844 &pin_range->range);
1845 if (IS_ERR(pin_range->pctldev)) {
1846 ret = PTR_ERR(pin_range->pctldev);
1847 chip_err(gc, "could not create pin range\n");
1848 kfree(pin_range);
1849 return ret;
1850 }
1851 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1852 gpio_offset, gpio_offset + npins - 1,
1853 pinctl_name,
1854 pin_offset, pin_offset + npins - 1);
1855
1856 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1857
1858 return 0;
1859 }
1860 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1861
1862 /**
1863 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1864 * @gc: the chip to remove all the mappings for
1865 */
gpiochip_remove_pin_ranges(struct gpio_chip * gc)1866 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1867 {
1868 struct gpio_pin_range *pin_range, *tmp;
1869 struct gpio_device *gdev = gc->gpiodev;
1870
1871 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1872 list_del(&pin_range->node);
1873 pinctrl_remove_gpio_range(pin_range->pctldev,
1874 &pin_range->range);
1875 kfree(pin_range);
1876 }
1877 }
1878 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1879
1880 #endif /* CONFIG_PINCTRL */
1881
1882 /* These "optional" allocation calls help prevent drivers from stomping
1883 * on each other, and help provide better diagnostics in debugfs.
1884 * They're called even less than the "set direction" calls.
1885 */
gpiod_request_commit(struct gpio_desc * desc,const char * label)1886 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
1887 {
1888 struct gpio_chip *gc = desc->gdev->chip;
1889 int ret;
1890 unsigned long flags;
1891 unsigned offset;
1892
1893 if (label) {
1894 label = kstrdup_const(label, GFP_KERNEL);
1895 if (!label)
1896 return -ENOMEM;
1897 }
1898
1899 spin_lock_irqsave(&gpio_lock, flags);
1900
1901 /* NOTE: gpio_request() can be called in early boot,
1902 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1903 */
1904
1905 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1906 desc_set_label(desc, label ? : "?");
1907 } else {
1908 ret = -EBUSY;
1909 goto out_free_unlock;
1910 }
1911
1912 if (gc->request) {
1913 /* gc->request may sleep */
1914 spin_unlock_irqrestore(&gpio_lock, flags);
1915 offset = gpio_chip_hwgpio(desc);
1916 if (gpiochip_line_is_valid(gc, offset))
1917 ret = gc->request(gc, offset);
1918 else
1919 ret = -EINVAL;
1920 spin_lock_irqsave(&gpio_lock, flags);
1921
1922 if (ret) {
1923 desc_set_label(desc, NULL);
1924 clear_bit(FLAG_REQUESTED, &desc->flags);
1925 goto out_free_unlock;
1926 }
1927 }
1928 if (gc->get_direction) {
1929 /* gc->get_direction may sleep */
1930 spin_unlock_irqrestore(&gpio_lock, flags);
1931 gpiod_get_direction(desc);
1932 spin_lock_irqsave(&gpio_lock, flags);
1933 }
1934 spin_unlock_irqrestore(&gpio_lock, flags);
1935 return 0;
1936
1937 out_free_unlock:
1938 spin_unlock_irqrestore(&gpio_lock, flags);
1939 kfree_const(label);
1940 return ret;
1941 }
1942
1943 /*
1944 * This descriptor validation needs to be inserted verbatim into each
1945 * function taking a descriptor, so we need to use a preprocessor
1946 * macro to avoid endless duplication. If the desc is NULL it is an
1947 * optional GPIO and calls should just bail out.
1948 */
validate_desc(const struct gpio_desc * desc,const char * func)1949 static int validate_desc(const struct gpio_desc *desc, const char *func)
1950 {
1951 if (!desc)
1952 return 0;
1953 if (IS_ERR(desc)) {
1954 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
1955 return PTR_ERR(desc);
1956 }
1957 if (!desc->gdev) {
1958 pr_warn("%s: invalid GPIO (no device)\n", func);
1959 return -EINVAL;
1960 }
1961 if (!desc->gdev->chip) {
1962 dev_warn(&desc->gdev->dev,
1963 "%s: backing chip is gone\n", func);
1964 return 0;
1965 }
1966 return 1;
1967 }
1968
1969 #define VALIDATE_DESC(desc) do { \
1970 int __valid = validate_desc(desc, __func__); \
1971 if (__valid <= 0) \
1972 return __valid; \
1973 } while (0)
1974
1975 #define VALIDATE_DESC_VOID(desc) do { \
1976 int __valid = validate_desc(desc, __func__); \
1977 if (__valid <= 0) \
1978 return; \
1979 } while (0)
1980
gpiod_request(struct gpio_desc * desc,const char * label)1981 int gpiod_request(struct gpio_desc *desc, const char *label)
1982 {
1983 int ret = -EPROBE_DEFER;
1984 struct gpio_device *gdev;
1985
1986 VALIDATE_DESC(desc);
1987 gdev = desc->gdev;
1988
1989 if (try_module_get(gdev->owner)) {
1990 ret = gpiod_request_commit(desc, label);
1991 if (ret)
1992 module_put(gdev->owner);
1993 else
1994 get_device(&gdev->dev);
1995 }
1996
1997 if (ret)
1998 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
1999
2000 return ret;
2001 }
2002
gpiod_free_commit(struct gpio_desc * desc)2003 static bool gpiod_free_commit(struct gpio_desc *desc)
2004 {
2005 bool ret = false;
2006 unsigned long flags;
2007 struct gpio_chip *gc;
2008
2009 might_sleep();
2010
2011 gpiod_unexport(desc);
2012
2013 spin_lock_irqsave(&gpio_lock, flags);
2014
2015 gc = desc->gdev->chip;
2016 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
2017 if (gc->free) {
2018 spin_unlock_irqrestore(&gpio_lock, flags);
2019 might_sleep_if(gc->can_sleep);
2020 gc->free(gc, gpio_chip_hwgpio(desc));
2021 spin_lock_irqsave(&gpio_lock, flags);
2022 }
2023 kfree_const(desc->label);
2024 desc_set_label(desc, NULL);
2025 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2026 clear_bit(FLAG_REQUESTED, &desc->flags);
2027 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2028 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2029 clear_bit(FLAG_PULL_UP, &desc->flags);
2030 clear_bit(FLAG_PULL_DOWN, &desc->flags);
2031 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
2032 clear_bit(FLAG_EDGE_RISING, &desc->flags);
2033 clear_bit(FLAG_EDGE_FALLING, &desc->flags);
2034 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2035 #ifdef CONFIG_OF_DYNAMIC
2036 desc->hog = NULL;
2037 #endif
2038 #ifdef CONFIG_GPIO_CDEV
2039 WRITE_ONCE(desc->debounce_period_us, 0);
2040 #endif
2041 ret = true;
2042 }
2043
2044 spin_unlock_irqrestore(&gpio_lock, flags);
2045 blocking_notifier_call_chain(&desc->gdev->notifier,
2046 GPIOLINE_CHANGED_RELEASED, desc);
2047
2048 return ret;
2049 }
2050
gpiod_free(struct gpio_desc * desc)2051 void gpiod_free(struct gpio_desc *desc)
2052 {
2053 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2054 module_put(desc->gdev->owner);
2055 put_device(&desc->gdev->dev);
2056 } else {
2057 WARN_ON(extra_checks);
2058 }
2059 }
2060
2061 /**
2062 * gpiochip_is_requested - return string iff signal was requested
2063 * @gc: controller managing the signal
2064 * @offset: of signal within controller's 0..(ngpio - 1) range
2065 *
2066 * Returns NULL if the GPIO is not currently requested, else a string.
2067 * The string returned is the label passed to gpio_request(); if none has been
2068 * passed it is a meaningless, non-NULL constant.
2069 *
2070 * This function is for use by GPIO controller drivers. The label can
2071 * help with diagnostics, and knowing that the signal is used as a GPIO
2072 * can help avoid accidentally multiplexing it to another controller.
2073 */
gpiochip_is_requested(struct gpio_chip * gc,unsigned int offset)2074 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
2075 {
2076 struct gpio_desc *desc;
2077
2078 desc = gpiochip_get_desc(gc, offset);
2079 if (IS_ERR(desc))
2080 return NULL;
2081
2082 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2083 return NULL;
2084 return desc->label;
2085 }
2086 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2087
2088 /**
2089 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2090 * @gc: GPIO chip
2091 * @hwnum: hardware number of the GPIO for which to request the descriptor
2092 * @label: label for the GPIO
2093 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2094 * specify things like line inversion semantics with the machine flags
2095 * such as GPIO_OUT_LOW
2096 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2097 * can be used to specify consumer semantics such as open drain
2098 *
2099 * Function allows GPIO chip drivers to request and use their own GPIO
2100 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2101 * function will not increase reference count of the GPIO chip module. This
2102 * allows the GPIO chip module to be unloaded as needed (we assume that the
2103 * GPIO chip driver handles freeing the GPIOs it has requested).
2104 *
2105 * Returns:
2106 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2107 * code on failure.
2108 */
gpiochip_request_own_desc(struct gpio_chip * gc,unsigned int hwnum,const char * label,enum gpio_lookup_flags lflags,enum gpiod_flags dflags)2109 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2110 unsigned int hwnum,
2111 const char *label,
2112 enum gpio_lookup_flags lflags,
2113 enum gpiod_flags dflags)
2114 {
2115 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2116 int ret;
2117
2118 if (IS_ERR(desc)) {
2119 chip_err(gc, "failed to get GPIO descriptor\n");
2120 return desc;
2121 }
2122
2123 ret = gpiod_request_commit(desc, label);
2124 if (ret < 0)
2125 return ERR_PTR(ret);
2126
2127 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2128 if (ret) {
2129 chip_err(gc, "setup of own GPIO %s failed\n", label);
2130 gpiod_free_commit(desc);
2131 return ERR_PTR(ret);
2132 }
2133
2134 return desc;
2135 }
2136 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2137
2138 /**
2139 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2140 * @desc: GPIO descriptor to free
2141 *
2142 * Function frees the given GPIO requested previously with
2143 * gpiochip_request_own_desc().
2144 */
gpiochip_free_own_desc(struct gpio_desc * desc)2145 void gpiochip_free_own_desc(struct gpio_desc *desc)
2146 {
2147 if (desc)
2148 gpiod_free_commit(desc);
2149 }
2150 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2151
2152 /*
2153 * Drivers MUST set GPIO direction before making get/set calls. In
2154 * some cases this is done in early boot, before IRQs are enabled.
2155 *
2156 * As a rule these aren't called more than once (except for drivers
2157 * using the open-drain emulation idiom) so these are natural places
2158 * to accumulate extra debugging checks. Note that we can't (yet)
2159 * rely on gpio_request() having been called beforehand.
2160 */
2161
gpio_do_set_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2162 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2163 unsigned long config)
2164 {
2165 if (!gc->set_config)
2166 return -ENOTSUPP;
2167
2168 return gc->set_config(gc, offset, config);
2169 }
2170
gpio_set_config_with_argument(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2171 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2172 enum pin_config_param mode,
2173 u32 argument)
2174 {
2175 struct gpio_chip *gc = desc->gdev->chip;
2176 unsigned long config;
2177
2178 config = pinconf_to_config_packed(mode, argument);
2179 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2180 }
2181
gpio_set_config_with_argument_optional(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2182 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2183 enum pin_config_param mode,
2184 u32 argument)
2185 {
2186 struct device *dev = &desc->gdev->dev;
2187 int gpio = gpio_chip_hwgpio(desc);
2188 int ret;
2189
2190 ret = gpio_set_config_with_argument(desc, mode, argument);
2191 if (ret != -ENOTSUPP)
2192 return ret;
2193
2194 switch (mode) {
2195 case PIN_CONFIG_PERSIST_STATE:
2196 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2197 break;
2198 default:
2199 break;
2200 }
2201
2202 return 0;
2203 }
2204
gpio_set_config(struct gpio_desc * desc,enum pin_config_param mode)2205 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2206 {
2207 return gpio_set_config_with_argument(desc, mode, 0);
2208 }
2209
gpio_set_bias(struct gpio_desc * desc)2210 static int gpio_set_bias(struct gpio_desc *desc)
2211 {
2212 enum pin_config_param bias;
2213 unsigned int arg;
2214
2215 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2216 bias = PIN_CONFIG_BIAS_DISABLE;
2217 else if (test_bit(FLAG_PULL_UP, &desc->flags))
2218 bias = PIN_CONFIG_BIAS_PULL_UP;
2219 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2220 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2221 else
2222 return 0;
2223
2224 switch (bias) {
2225 case PIN_CONFIG_BIAS_PULL_DOWN:
2226 case PIN_CONFIG_BIAS_PULL_UP:
2227 arg = 1;
2228 break;
2229
2230 default:
2231 arg = 0;
2232 break;
2233 }
2234
2235 return gpio_set_config_with_argument_optional(desc, bias, arg);
2236 }
2237
2238 /**
2239 * gpio_set_debounce_timeout() - Set debounce timeout
2240 * @desc: GPIO descriptor to set the debounce timeout
2241 * @debounce: Debounce timeout in microseconds
2242 *
2243 * The function calls the certain GPIO driver to set debounce timeout
2244 * in the hardware.
2245 *
2246 * Returns 0 on success, or negative error code otherwise.
2247 */
gpio_set_debounce_timeout(struct gpio_desc * desc,unsigned int debounce)2248 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2249 {
2250 return gpio_set_config_with_argument_optional(desc,
2251 PIN_CONFIG_INPUT_DEBOUNCE,
2252 debounce);
2253 }
2254
2255 /**
2256 * gpiod_direction_input - set the GPIO direction to input
2257 * @desc: GPIO to set to input
2258 *
2259 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2260 * be called safely on it.
2261 *
2262 * Return 0 in case of success, else an error code.
2263 */
gpiod_direction_input(struct gpio_desc * desc)2264 int gpiod_direction_input(struct gpio_desc *desc)
2265 {
2266 struct gpio_chip *gc;
2267 int ret = 0;
2268
2269 VALIDATE_DESC(desc);
2270 gc = desc->gdev->chip;
2271
2272 /*
2273 * It is legal to have no .get() and .direction_input() specified if
2274 * the chip is output-only, but you can't specify .direction_input()
2275 * and not support the .get() operation, that doesn't make sense.
2276 */
2277 if (!gc->get && gc->direction_input) {
2278 gpiod_warn(desc,
2279 "%s: missing get() but have direction_input()\n",
2280 __func__);
2281 return -EIO;
2282 }
2283
2284 /*
2285 * If we have a .direction_input() callback, things are simple,
2286 * just call it. Else we are some input-only chip so try to check the
2287 * direction (if .get_direction() is supported) else we silently
2288 * assume we are in input mode after this.
2289 */
2290 if (gc->direction_input) {
2291 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2292 } else if (gc->get_direction &&
2293 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2294 gpiod_warn(desc,
2295 "%s: missing direction_input() operation and line is output\n",
2296 __func__);
2297 return -EIO;
2298 }
2299 if (ret == 0) {
2300 clear_bit(FLAG_IS_OUT, &desc->flags);
2301 ret = gpio_set_bias(desc);
2302 }
2303
2304 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2305
2306 return ret;
2307 }
2308 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2309
gpiod_direction_output_raw_commit(struct gpio_desc * desc,int value)2310 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2311 {
2312 struct gpio_chip *gc = desc->gdev->chip;
2313 int val = !!value;
2314 int ret = 0;
2315
2316 /*
2317 * It's OK not to specify .direction_output() if the gpiochip is
2318 * output-only, but if there is then not even a .set() operation it
2319 * is pretty tricky to drive the output line.
2320 */
2321 if (!gc->set && !gc->direction_output) {
2322 gpiod_warn(desc,
2323 "%s: missing set() and direction_output() operations\n",
2324 __func__);
2325 return -EIO;
2326 }
2327
2328 if (gc->direction_output) {
2329 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2330 } else {
2331 /* Check that we are in output mode if we can */
2332 if (gc->get_direction &&
2333 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2334 gpiod_warn(desc,
2335 "%s: missing direction_output() operation\n",
2336 __func__);
2337 return -EIO;
2338 }
2339 /*
2340 * If we can't actively set the direction, we are some
2341 * output-only chip, so just drive the output as desired.
2342 */
2343 gc->set(gc, gpio_chip_hwgpio(desc), val);
2344 }
2345
2346 if (!ret)
2347 set_bit(FLAG_IS_OUT, &desc->flags);
2348 trace_gpio_value(desc_to_gpio(desc), 0, val);
2349 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2350 return ret;
2351 }
2352
2353 /**
2354 * gpiod_direction_output_raw - set the GPIO direction to output
2355 * @desc: GPIO to set to output
2356 * @value: initial output value of the GPIO
2357 *
2358 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2359 * be called safely on it. The initial value of the output must be specified
2360 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2361 *
2362 * Return 0 in case of success, else an error code.
2363 */
gpiod_direction_output_raw(struct gpio_desc * desc,int value)2364 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2365 {
2366 VALIDATE_DESC(desc);
2367 return gpiod_direction_output_raw_commit(desc, value);
2368 }
2369 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2370
2371 /**
2372 * gpiod_direction_output - set the GPIO direction to output
2373 * @desc: GPIO to set to output
2374 * @value: initial output value of the GPIO
2375 *
2376 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2377 * be called safely on it. The initial value of the output must be specified
2378 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2379 * account.
2380 *
2381 * Return 0 in case of success, else an error code.
2382 */
gpiod_direction_output(struct gpio_desc * desc,int value)2383 int gpiod_direction_output(struct gpio_desc *desc, int value)
2384 {
2385 int ret;
2386
2387 VALIDATE_DESC(desc);
2388 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2389 value = !value;
2390 else
2391 value = !!value;
2392
2393 /* GPIOs used for enabled IRQs shall not be set as output */
2394 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2395 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2396 gpiod_err(desc,
2397 "%s: tried to set a GPIO tied to an IRQ as output\n",
2398 __func__);
2399 return -EIO;
2400 }
2401
2402 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2403 /* First see if we can enable open drain in hardware */
2404 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2405 if (!ret)
2406 goto set_output_value;
2407 /* Emulate open drain by not actively driving the line high */
2408 if (value) {
2409 ret = gpiod_direction_input(desc);
2410 goto set_output_flag;
2411 }
2412 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2413 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2414 if (!ret)
2415 goto set_output_value;
2416 /* Emulate open source by not actively driving the line low */
2417 if (!value) {
2418 ret = gpiod_direction_input(desc);
2419 goto set_output_flag;
2420 }
2421 } else {
2422 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2423 }
2424
2425 set_output_value:
2426 ret = gpio_set_bias(desc);
2427 if (ret)
2428 return ret;
2429 return gpiod_direction_output_raw_commit(desc, value);
2430
2431 set_output_flag:
2432 /*
2433 * When emulating open-source or open-drain functionalities by not
2434 * actively driving the line (setting mode to input) we still need to
2435 * set the IS_OUT flag or otherwise we won't be able to set the line
2436 * value anymore.
2437 */
2438 if (ret == 0)
2439 set_bit(FLAG_IS_OUT, &desc->flags);
2440 return ret;
2441 }
2442 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2443
2444 /**
2445 * gpiod_set_config - sets @config for a GPIO
2446 * @desc: descriptor of the GPIO for which to set the configuration
2447 * @config: Same packed config format as generic pinconf
2448 *
2449 * Returns:
2450 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2451 * configuration.
2452 */
gpiod_set_config(struct gpio_desc * desc,unsigned long config)2453 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2454 {
2455 struct gpio_chip *gc;
2456
2457 VALIDATE_DESC(desc);
2458 gc = desc->gdev->chip;
2459
2460 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2461 }
2462 EXPORT_SYMBOL_GPL(gpiod_set_config);
2463
2464 /**
2465 * gpiod_set_debounce - sets @debounce time for a GPIO
2466 * @desc: descriptor of the GPIO for which to set debounce time
2467 * @debounce: debounce time in microseconds
2468 *
2469 * Returns:
2470 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2471 * debounce time.
2472 */
gpiod_set_debounce(struct gpio_desc * desc,unsigned int debounce)2473 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2474 {
2475 unsigned long config;
2476
2477 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2478 return gpiod_set_config(desc, config);
2479 }
2480 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2481
2482 /**
2483 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2484 * @desc: descriptor of the GPIO for which to configure persistence
2485 * @transitory: True to lose state on suspend or reset, false for persistence
2486 *
2487 * Returns:
2488 * 0 on success, otherwise a negative error code.
2489 */
gpiod_set_transitory(struct gpio_desc * desc,bool transitory)2490 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2491 {
2492 VALIDATE_DESC(desc);
2493 /*
2494 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2495 * persistence state.
2496 */
2497 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2498
2499 /* If the driver supports it, set the persistence state now */
2500 return gpio_set_config_with_argument_optional(desc,
2501 PIN_CONFIG_PERSIST_STATE,
2502 !transitory);
2503 }
2504 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2505
2506 /**
2507 * gpiod_is_active_low - test whether a GPIO is active-low or not
2508 * @desc: the gpio descriptor to test
2509 *
2510 * Returns 1 if the GPIO is active-low, 0 otherwise.
2511 */
gpiod_is_active_low(const struct gpio_desc * desc)2512 int gpiod_is_active_low(const struct gpio_desc *desc)
2513 {
2514 VALIDATE_DESC(desc);
2515 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2516 }
2517 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2518
2519 /**
2520 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2521 * @desc: the gpio descriptor to change
2522 */
gpiod_toggle_active_low(struct gpio_desc * desc)2523 void gpiod_toggle_active_low(struct gpio_desc *desc)
2524 {
2525 VALIDATE_DESC_VOID(desc);
2526 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2527 }
2528 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2529
2530 /* I/O calls are only valid after configuration completed; the relevant
2531 * "is this a valid GPIO" error checks should already have been done.
2532 *
2533 * "Get" operations are often inlinable as reading a pin value register,
2534 * and masking the relevant bit in that register.
2535 *
2536 * When "set" operations are inlinable, they involve writing that mask to
2537 * one register to set a low value, or a different register to set it high.
2538 * Otherwise locking is needed, so there may be little value to inlining.
2539 *
2540 *------------------------------------------------------------------------
2541 *
2542 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2543 * have requested the GPIO. That can include implicit requesting by
2544 * a direction setting call. Marking a gpio as requested locks its chip
2545 * in memory, guaranteeing that these table lookups need no more locking
2546 * and that gpiochip_remove() will fail.
2547 *
2548 * REVISIT when debugging, consider adding some instrumentation to ensure
2549 * that the GPIO was actually requested.
2550 */
2551
gpiod_get_raw_value_commit(const struct gpio_desc * desc)2552 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2553 {
2554 struct gpio_chip *gc;
2555 int offset;
2556 int value;
2557
2558 gc = desc->gdev->chip;
2559 offset = gpio_chip_hwgpio(desc);
2560 value = gc->get ? gc->get(gc, offset) : -EIO;
2561 value = value < 0 ? value : !!value;
2562 trace_gpio_value(desc_to_gpio(desc), 1, value);
2563 return value;
2564 }
2565
gpio_chip_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)2566 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2567 unsigned long *mask, unsigned long *bits)
2568 {
2569 if (gc->get_multiple)
2570 return gc->get_multiple(gc, mask, bits);
2571 if (gc->get) {
2572 int i, value;
2573
2574 for_each_set_bit(i, mask, gc->ngpio) {
2575 value = gc->get(gc, i);
2576 if (value < 0)
2577 return value;
2578 __assign_bit(i, bits, value);
2579 }
2580 return 0;
2581 }
2582 return -EIO;
2583 }
2584
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)2585 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2586 unsigned int array_size,
2587 struct gpio_desc **desc_array,
2588 struct gpio_array *array_info,
2589 unsigned long *value_bitmap)
2590 {
2591 int ret, i = 0;
2592
2593 /*
2594 * Validate array_info against desc_array and its size.
2595 * It should immediately follow desc_array if both
2596 * have been obtained from the same gpiod_get_array() call.
2597 */
2598 if (array_info && array_info->desc == desc_array &&
2599 array_size <= array_info->size &&
2600 (void *)array_info == desc_array + array_info->size) {
2601 if (!can_sleep)
2602 WARN_ON(array_info->chip->can_sleep);
2603
2604 ret = gpio_chip_get_multiple(array_info->chip,
2605 array_info->get_mask,
2606 value_bitmap);
2607 if (ret)
2608 return ret;
2609
2610 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2611 bitmap_xor(value_bitmap, value_bitmap,
2612 array_info->invert_mask, array_size);
2613
2614 i = find_first_zero_bit(array_info->get_mask, array_size);
2615 if (i == array_size)
2616 return 0;
2617 } else {
2618 array_info = NULL;
2619 }
2620
2621 while (i < array_size) {
2622 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2623 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2624 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2625 unsigned long *mask, *bits;
2626 int first, j;
2627
2628 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2629 mask = fastpath_mask;
2630 bits = fastpath_bits;
2631 } else {
2632 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2633
2634 mask = bitmap_alloc(gc->ngpio, flags);
2635 if (!mask)
2636 return -ENOMEM;
2637
2638 bits = bitmap_alloc(gc->ngpio, flags);
2639 if (!bits) {
2640 bitmap_free(mask);
2641 return -ENOMEM;
2642 }
2643 }
2644
2645 bitmap_zero(mask, gc->ngpio);
2646
2647 if (!can_sleep)
2648 WARN_ON(gc->can_sleep);
2649
2650 /* collect all inputs belonging to the same chip */
2651 first = i;
2652 do {
2653 const struct gpio_desc *desc = desc_array[i];
2654 int hwgpio = gpio_chip_hwgpio(desc);
2655
2656 __set_bit(hwgpio, mask);
2657 i++;
2658
2659 if (array_info)
2660 i = find_next_zero_bit(array_info->get_mask,
2661 array_size, i);
2662 } while ((i < array_size) &&
2663 (desc_array[i]->gdev->chip == gc));
2664
2665 ret = gpio_chip_get_multiple(gc, mask, bits);
2666 if (ret) {
2667 if (mask != fastpath_mask)
2668 bitmap_free(mask);
2669 if (bits != fastpath_bits)
2670 bitmap_free(bits);
2671 return ret;
2672 }
2673
2674 for (j = first; j < i; ) {
2675 const struct gpio_desc *desc = desc_array[j];
2676 int hwgpio = gpio_chip_hwgpio(desc);
2677 int value = test_bit(hwgpio, bits);
2678
2679 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2680 value = !value;
2681 __assign_bit(j, value_bitmap, value);
2682 trace_gpio_value(desc_to_gpio(desc), 1, value);
2683 j++;
2684
2685 if (array_info)
2686 j = find_next_zero_bit(array_info->get_mask, i,
2687 j);
2688 }
2689
2690 if (mask != fastpath_mask)
2691 bitmap_free(mask);
2692 if (bits != fastpath_bits)
2693 bitmap_free(bits);
2694 }
2695 return 0;
2696 }
2697
2698 /**
2699 * gpiod_get_raw_value() - return a gpio's raw value
2700 * @desc: gpio whose value will be returned
2701 *
2702 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2703 * its ACTIVE_LOW status, or negative errno on failure.
2704 *
2705 * This function can be called from contexts where we cannot sleep, and will
2706 * complain if the GPIO chip functions potentially sleep.
2707 */
gpiod_get_raw_value(const struct gpio_desc * desc)2708 int gpiod_get_raw_value(const struct gpio_desc *desc)
2709 {
2710 VALIDATE_DESC(desc);
2711 /* Should be using gpiod_get_raw_value_cansleep() */
2712 WARN_ON(desc->gdev->chip->can_sleep);
2713 return gpiod_get_raw_value_commit(desc);
2714 }
2715 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2716
2717 /**
2718 * gpiod_get_value() - return a gpio's value
2719 * @desc: gpio whose value will be returned
2720 *
2721 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2722 * account, or negative errno on failure.
2723 *
2724 * This function can be called from contexts where we cannot sleep, and will
2725 * complain if the GPIO chip functions potentially sleep.
2726 */
gpiod_get_value(const struct gpio_desc * desc)2727 int gpiod_get_value(const struct gpio_desc *desc)
2728 {
2729 int value;
2730
2731 VALIDATE_DESC(desc);
2732 /* Should be using gpiod_get_value_cansleep() */
2733 WARN_ON(desc->gdev->chip->can_sleep);
2734
2735 value = gpiod_get_raw_value_commit(desc);
2736 if (value < 0)
2737 return value;
2738
2739 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2740 value = !value;
2741
2742 return value;
2743 }
2744 EXPORT_SYMBOL_GPL(gpiod_get_value);
2745
2746 /**
2747 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2748 * @array_size: number of elements in the descriptor array / value bitmap
2749 * @desc_array: array of GPIO descriptors whose values will be read
2750 * @array_info: information on applicability of fast bitmap processing path
2751 * @value_bitmap: bitmap to store the read values
2752 *
2753 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2754 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2755 * else an error code.
2756 *
2757 * This function can be called from contexts where we cannot sleep,
2758 * and it will complain if the GPIO chip functions potentially sleep.
2759 */
gpiod_get_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2760 int gpiod_get_raw_array_value(unsigned int array_size,
2761 struct gpio_desc **desc_array,
2762 struct gpio_array *array_info,
2763 unsigned long *value_bitmap)
2764 {
2765 if (!desc_array)
2766 return -EINVAL;
2767 return gpiod_get_array_value_complex(true, false, array_size,
2768 desc_array, array_info,
2769 value_bitmap);
2770 }
2771 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2772
2773 /**
2774 * gpiod_get_array_value() - read values from an array of GPIOs
2775 * @array_size: number of elements in the descriptor array / value bitmap
2776 * @desc_array: array of GPIO descriptors whose values will be read
2777 * @array_info: information on applicability of fast bitmap processing path
2778 * @value_bitmap: bitmap to store the read values
2779 *
2780 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2781 * into account. Return 0 in case of success, else an error code.
2782 *
2783 * This function can be called from contexts where we cannot sleep,
2784 * and it will complain if the GPIO chip functions potentially sleep.
2785 */
gpiod_get_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2786 int gpiod_get_array_value(unsigned int array_size,
2787 struct gpio_desc **desc_array,
2788 struct gpio_array *array_info,
2789 unsigned long *value_bitmap)
2790 {
2791 if (!desc_array)
2792 return -EINVAL;
2793 return gpiod_get_array_value_complex(false, false, array_size,
2794 desc_array, array_info,
2795 value_bitmap);
2796 }
2797 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2798
2799 /*
2800 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2801 * @desc: gpio descriptor whose state need to be set.
2802 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2803 */
gpio_set_open_drain_value_commit(struct gpio_desc * desc,bool value)2804 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2805 {
2806 int ret = 0;
2807 struct gpio_chip *gc = desc->gdev->chip;
2808 int offset = gpio_chip_hwgpio(desc);
2809
2810 if (value) {
2811 ret = gc->direction_input(gc, offset);
2812 } else {
2813 ret = gc->direction_output(gc, offset, 0);
2814 if (!ret)
2815 set_bit(FLAG_IS_OUT, &desc->flags);
2816 }
2817 trace_gpio_direction(desc_to_gpio(desc), value, ret);
2818 if (ret < 0)
2819 gpiod_err(desc,
2820 "%s: Error in set_value for open drain err %d\n",
2821 __func__, ret);
2822 }
2823
2824 /*
2825 * _gpio_set_open_source_value() - Set the open source gpio's value.
2826 * @desc: gpio descriptor whose state need to be set.
2827 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2828 */
gpio_set_open_source_value_commit(struct gpio_desc * desc,bool value)2829 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2830 {
2831 int ret = 0;
2832 struct gpio_chip *gc = desc->gdev->chip;
2833 int offset = gpio_chip_hwgpio(desc);
2834
2835 if (value) {
2836 ret = gc->direction_output(gc, offset, 1);
2837 if (!ret)
2838 set_bit(FLAG_IS_OUT, &desc->flags);
2839 } else {
2840 ret = gc->direction_input(gc, offset);
2841 }
2842 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2843 if (ret < 0)
2844 gpiod_err(desc,
2845 "%s: Error in set_value for open source err %d\n",
2846 __func__, ret);
2847 }
2848
gpiod_set_raw_value_commit(struct gpio_desc * desc,bool value)2849 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2850 {
2851 struct gpio_chip *gc;
2852
2853 gc = desc->gdev->chip;
2854 trace_gpio_value(desc_to_gpio(desc), 0, value);
2855 gc->set(gc, gpio_chip_hwgpio(desc), value);
2856 }
2857
2858 /*
2859 * set multiple outputs on the same chip;
2860 * use the chip's set_multiple function if available;
2861 * otherwise set the outputs sequentially;
2862 * @chip: the GPIO chip we operate on
2863 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2864 * defines which outputs are to be changed
2865 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2866 * defines the values the outputs specified by mask are to be set to
2867 */
gpio_chip_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)2868 static void gpio_chip_set_multiple(struct gpio_chip *gc,
2869 unsigned long *mask, unsigned long *bits)
2870 {
2871 if (gc->set_multiple) {
2872 gc->set_multiple(gc, mask, bits);
2873 } else {
2874 unsigned int i;
2875
2876 /* set outputs if the corresponding mask bit is set */
2877 for_each_set_bit(i, mask, gc->ngpio)
2878 gc->set(gc, i, test_bit(i, bits));
2879 }
2880 }
2881
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)2882 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2883 unsigned int array_size,
2884 struct gpio_desc **desc_array,
2885 struct gpio_array *array_info,
2886 unsigned long *value_bitmap)
2887 {
2888 int i = 0;
2889
2890 /*
2891 * Validate array_info against desc_array and its size.
2892 * It should immediately follow desc_array if both
2893 * have been obtained from the same gpiod_get_array() call.
2894 */
2895 if (array_info && array_info->desc == desc_array &&
2896 array_size <= array_info->size &&
2897 (void *)array_info == desc_array + array_info->size) {
2898 if (!can_sleep)
2899 WARN_ON(array_info->chip->can_sleep);
2900
2901 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2902 bitmap_xor(value_bitmap, value_bitmap,
2903 array_info->invert_mask, array_size);
2904
2905 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2906 value_bitmap);
2907
2908 i = find_first_zero_bit(array_info->set_mask, array_size);
2909 if (i == array_size)
2910 return 0;
2911 } else {
2912 array_info = NULL;
2913 }
2914
2915 while (i < array_size) {
2916 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2917 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2918 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2919 unsigned long *mask, *bits;
2920 int count = 0;
2921
2922 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2923 mask = fastpath_mask;
2924 bits = fastpath_bits;
2925 } else {
2926 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2927
2928 mask = bitmap_alloc(gc->ngpio, flags);
2929 if (!mask)
2930 return -ENOMEM;
2931
2932 bits = bitmap_alloc(gc->ngpio, flags);
2933 if (!bits) {
2934 bitmap_free(mask);
2935 return -ENOMEM;
2936 }
2937 }
2938
2939 bitmap_zero(mask, gc->ngpio);
2940
2941 if (!can_sleep)
2942 WARN_ON(gc->can_sleep);
2943
2944 do {
2945 struct gpio_desc *desc = desc_array[i];
2946 int hwgpio = gpio_chip_hwgpio(desc);
2947 int value = test_bit(i, value_bitmap);
2948
2949 /*
2950 * Pins applicable for fast input but not for
2951 * fast output processing may have been already
2952 * inverted inside the fast path, skip them.
2953 */
2954 if (!raw && !(array_info &&
2955 test_bit(i, array_info->invert_mask)) &&
2956 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2957 value = !value;
2958 trace_gpio_value(desc_to_gpio(desc), 0, value);
2959 /*
2960 * collect all normal outputs belonging to the same chip
2961 * open drain and open source outputs are set individually
2962 */
2963 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2964 gpio_set_open_drain_value_commit(desc, value);
2965 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2966 gpio_set_open_source_value_commit(desc, value);
2967 } else {
2968 __set_bit(hwgpio, mask);
2969 __assign_bit(hwgpio, bits, value);
2970 count++;
2971 }
2972 i++;
2973
2974 if (array_info)
2975 i = find_next_zero_bit(array_info->set_mask,
2976 array_size, i);
2977 } while ((i < array_size) &&
2978 (desc_array[i]->gdev->chip == gc));
2979 /* push collected bits to outputs */
2980 if (count != 0)
2981 gpio_chip_set_multiple(gc, mask, bits);
2982
2983 if (mask != fastpath_mask)
2984 bitmap_free(mask);
2985 if (bits != fastpath_bits)
2986 bitmap_free(bits);
2987 }
2988 return 0;
2989 }
2990
2991 /**
2992 * gpiod_set_raw_value() - assign a gpio's raw value
2993 * @desc: gpio whose value will be assigned
2994 * @value: value to assign
2995 *
2996 * Set the raw value of the GPIO, i.e. the value of its physical line without
2997 * regard for its ACTIVE_LOW status.
2998 *
2999 * This function can be called from contexts where we cannot sleep, and will
3000 * complain if the GPIO chip functions potentially sleep.
3001 */
gpiod_set_raw_value(struct gpio_desc * desc,int value)3002 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3003 {
3004 VALIDATE_DESC_VOID(desc);
3005 /* Should be using gpiod_set_raw_value_cansleep() */
3006 WARN_ON(desc->gdev->chip->can_sleep);
3007 gpiod_set_raw_value_commit(desc, value);
3008 }
3009 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3010
3011 /**
3012 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3013 * @desc: the descriptor to set the value on
3014 * @value: value to set
3015 *
3016 * This sets the value of a GPIO line backing a descriptor, applying
3017 * different semantic quirks like active low and open drain/source
3018 * handling.
3019 */
gpiod_set_value_nocheck(struct gpio_desc * desc,int value)3020 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3021 {
3022 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3023 value = !value;
3024 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3025 gpio_set_open_drain_value_commit(desc, value);
3026 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3027 gpio_set_open_source_value_commit(desc, value);
3028 else
3029 gpiod_set_raw_value_commit(desc, value);
3030 }
3031
3032 /**
3033 * gpiod_set_value() - assign a gpio's value
3034 * @desc: gpio whose value will be assigned
3035 * @value: value to assign
3036 *
3037 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3038 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3039 *
3040 * This function can be called from contexts where we cannot sleep, and will
3041 * complain if the GPIO chip functions potentially sleep.
3042 */
gpiod_set_value(struct gpio_desc * desc,int value)3043 void gpiod_set_value(struct gpio_desc *desc, int value)
3044 {
3045 VALIDATE_DESC_VOID(desc);
3046 /* Should be using gpiod_set_value_cansleep() */
3047 WARN_ON(desc->gdev->chip->can_sleep);
3048 gpiod_set_value_nocheck(desc, value);
3049 }
3050 EXPORT_SYMBOL_GPL(gpiod_set_value);
3051
3052 /**
3053 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3054 * @array_size: number of elements in the descriptor array / value bitmap
3055 * @desc_array: array of GPIO descriptors whose values will be assigned
3056 * @array_info: information on applicability of fast bitmap processing path
3057 * @value_bitmap: bitmap of values to assign
3058 *
3059 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3060 * without regard for their ACTIVE_LOW status.
3061 *
3062 * This function can be called from contexts where we cannot sleep, and will
3063 * complain if the GPIO chip functions potentially sleep.
3064 */
gpiod_set_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3065 int gpiod_set_raw_array_value(unsigned int array_size,
3066 struct gpio_desc **desc_array,
3067 struct gpio_array *array_info,
3068 unsigned long *value_bitmap)
3069 {
3070 if (!desc_array)
3071 return -EINVAL;
3072 return gpiod_set_array_value_complex(true, false, array_size,
3073 desc_array, array_info, value_bitmap);
3074 }
3075 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3076
3077 /**
3078 * gpiod_set_array_value() - assign values to an array of GPIOs
3079 * @array_size: number of elements in the descriptor array / value bitmap
3080 * @desc_array: array of GPIO descriptors whose values will be assigned
3081 * @array_info: information on applicability of fast bitmap processing path
3082 * @value_bitmap: bitmap of values to assign
3083 *
3084 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3085 * into account.
3086 *
3087 * This function can be called from contexts where we cannot sleep, and will
3088 * complain if the GPIO chip functions potentially sleep.
3089 */
gpiod_set_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3090 int gpiod_set_array_value(unsigned int array_size,
3091 struct gpio_desc **desc_array,
3092 struct gpio_array *array_info,
3093 unsigned long *value_bitmap)
3094 {
3095 if (!desc_array)
3096 return -EINVAL;
3097 return gpiod_set_array_value_complex(false, false, array_size,
3098 desc_array, array_info,
3099 value_bitmap);
3100 }
3101 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3102
3103 /**
3104 * gpiod_cansleep() - report whether gpio value access may sleep
3105 * @desc: gpio to check
3106 *
3107 */
gpiod_cansleep(const struct gpio_desc * desc)3108 int gpiod_cansleep(const struct gpio_desc *desc)
3109 {
3110 VALIDATE_DESC(desc);
3111 return desc->gdev->chip->can_sleep;
3112 }
3113 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3114
3115 /**
3116 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3117 * @desc: gpio to set the consumer name on
3118 * @name: the new consumer name
3119 */
gpiod_set_consumer_name(struct gpio_desc * desc,const char * name)3120 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3121 {
3122 VALIDATE_DESC(desc);
3123 if (name) {
3124 name = kstrdup_const(name, GFP_KERNEL);
3125 if (!name)
3126 return -ENOMEM;
3127 }
3128
3129 kfree_const(desc->label);
3130 desc_set_label(desc, name);
3131
3132 return 0;
3133 }
3134 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3135
3136 /**
3137 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3138 * @desc: gpio whose IRQ will be returned (already requested)
3139 *
3140 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3141 * error.
3142 */
gpiod_to_irq(const struct gpio_desc * desc)3143 int gpiod_to_irq(const struct gpio_desc *desc)
3144 {
3145 struct gpio_chip *gc;
3146 int offset;
3147
3148 /*
3149 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3150 * requires this function to not return zero on an invalid descriptor
3151 * but rather a negative error number.
3152 */
3153 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3154 return -EINVAL;
3155
3156 gc = desc->gdev->chip;
3157 offset = gpio_chip_hwgpio(desc);
3158 if (gc->to_irq) {
3159 int retirq = gc->to_irq(gc, offset);
3160
3161 /* Zero means NO_IRQ */
3162 if (!retirq)
3163 return -ENXIO;
3164
3165 return retirq;
3166 }
3167 #ifdef CONFIG_GPIOLIB_IRQCHIP
3168 if (gc->irq.chip) {
3169 /*
3170 * Avoid race condition with other code, which tries to lookup
3171 * an IRQ before the irqchip has been properly registered,
3172 * i.e. while gpiochip is still being brought up.
3173 */
3174 return -EPROBE_DEFER;
3175 }
3176 #endif
3177 return -ENXIO;
3178 }
3179 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3180
3181 /**
3182 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3183 * @gc: the chip the GPIO to lock belongs to
3184 * @offset: the offset of the GPIO to lock as IRQ
3185 *
3186 * This is used directly by GPIO drivers that want to lock down
3187 * a certain GPIO line to be used for IRQs.
3188 */
gpiochip_lock_as_irq(struct gpio_chip * gc,unsigned int offset)3189 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3190 {
3191 struct gpio_desc *desc;
3192
3193 desc = gpiochip_get_desc(gc, offset);
3194 if (IS_ERR(desc))
3195 return PTR_ERR(desc);
3196
3197 /*
3198 * If it's fast: flush the direction setting if something changed
3199 * behind our back
3200 */
3201 if (!gc->can_sleep && gc->get_direction) {
3202 int dir = gpiod_get_direction(desc);
3203
3204 if (dir < 0) {
3205 chip_err(gc, "%s: cannot get GPIO direction\n",
3206 __func__);
3207 return dir;
3208 }
3209 }
3210
3211 /* To be valid for IRQ the line needs to be input or open drain */
3212 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3213 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3214 chip_err(gc,
3215 "%s: tried to flag a GPIO set as output for IRQ\n",
3216 __func__);
3217 return -EIO;
3218 }
3219
3220 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3221 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3222
3223 /*
3224 * If the consumer has not set up a label (such as when the
3225 * IRQ is referenced from .to_irq()) we set up a label here
3226 * so it is clear this is used as an interrupt.
3227 */
3228 if (!desc->label)
3229 desc_set_label(desc, "interrupt");
3230
3231 return 0;
3232 }
3233 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3234
3235 /**
3236 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3237 * @gc: the chip the GPIO to lock belongs to
3238 * @offset: the offset of the GPIO to lock as IRQ
3239 *
3240 * This is used directly by GPIO drivers that want to indicate
3241 * that a certain GPIO is no longer used exclusively for IRQ.
3242 */
gpiochip_unlock_as_irq(struct gpio_chip * gc,unsigned int offset)3243 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3244 {
3245 struct gpio_desc *desc;
3246
3247 desc = gpiochip_get_desc(gc, offset);
3248 if (IS_ERR(desc))
3249 return;
3250
3251 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3252 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3253
3254 /* If we only had this marking, erase it */
3255 if (desc->label && !strcmp(desc->label, "interrupt"))
3256 desc_set_label(desc, NULL);
3257 }
3258 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3259
gpiochip_disable_irq(struct gpio_chip * gc,unsigned int offset)3260 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3261 {
3262 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3263
3264 if (!IS_ERR(desc) &&
3265 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3266 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3267 }
3268 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3269
gpiochip_enable_irq(struct gpio_chip * gc,unsigned int offset)3270 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3271 {
3272 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3273
3274 if (!IS_ERR(desc) &&
3275 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3276 /*
3277 * We must not be output when using IRQ UNLESS we are
3278 * open drain.
3279 */
3280 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3281 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3282 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3283 }
3284 }
3285 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3286
gpiochip_line_is_irq(struct gpio_chip * gc,unsigned int offset)3287 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3288 {
3289 if (offset >= gc->ngpio)
3290 return false;
3291
3292 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3293 }
3294 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3295
gpiochip_reqres_irq(struct gpio_chip * gc,unsigned int offset)3296 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3297 {
3298 int ret;
3299
3300 if (!try_module_get(gc->gpiodev->owner))
3301 return -ENODEV;
3302
3303 ret = gpiochip_lock_as_irq(gc, offset);
3304 if (ret) {
3305 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3306 module_put(gc->gpiodev->owner);
3307 return ret;
3308 }
3309 return 0;
3310 }
3311 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3312
gpiochip_relres_irq(struct gpio_chip * gc,unsigned int offset)3313 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3314 {
3315 gpiochip_unlock_as_irq(gc, offset);
3316 module_put(gc->gpiodev->owner);
3317 }
3318 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3319
gpiochip_line_is_open_drain(struct gpio_chip * gc,unsigned int offset)3320 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3321 {
3322 if (offset >= gc->ngpio)
3323 return false;
3324
3325 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3326 }
3327 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3328
gpiochip_line_is_open_source(struct gpio_chip * gc,unsigned int offset)3329 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3330 {
3331 if (offset >= gc->ngpio)
3332 return false;
3333
3334 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3335 }
3336 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3337
gpiochip_line_is_persistent(struct gpio_chip * gc,unsigned int offset)3338 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3339 {
3340 if (offset >= gc->ngpio)
3341 return false;
3342
3343 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3344 }
3345 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3346
3347 /**
3348 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3349 * @desc: gpio whose value will be returned
3350 *
3351 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3352 * its ACTIVE_LOW status, or negative errno on failure.
3353 *
3354 * This function is to be called from contexts that can sleep.
3355 */
gpiod_get_raw_value_cansleep(const struct gpio_desc * desc)3356 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3357 {
3358 might_sleep_if(extra_checks);
3359 VALIDATE_DESC(desc);
3360 return gpiod_get_raw_value_commit(desc);
3361 }
3362 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3363
3364 /**
3365 * gpiod_get_value_cansleep() - return a gpio's value
3366 * @desc: gpio whose value will be returned
3367 *
3368 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3369 * account, or negative errno on failure.
3370 *
3371 * This function is to be called from contexts that can sleep.
3372 */
gpiod_get_value_cansleep(const struct gpio_desc * desc)3373 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3374 {
3375 int value;
3376
3377 might_sleep_if(extra_checks);
3378 VALIDATE_DESC(desc);
3379 value = gpiod_get_raw_value_commit(desc);
3380 if (value < 0)
3381 return value;
3382
3383 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3384 value = !value;
3385
3386 return value;
3387 }
3388 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3389
3390 /**
3391 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3392 * @array_size: number of elements in the descriptor array / value bitmap
3393 * @desc_array: array of GPIO descriptors whose values will be read
3394 * @array_info: information on applicability of fast bitmap processing path
3395 * @value_bitmap: bitmap to store the read values
3396 *
3397 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3398 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3399 * else an error code.
3400 *
3401 * This function is to be called from contexts that can sleep.
3402 */
gpiod_get_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3403 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3404 struct gpio_desc **desc_array,
3405 struct gpio_array *array_info,
3406 unsigned long *value_bitmap)
3407 {
3408 might_sleep_if(extra_checks);
3409 if (!desc_array)
3410 return -EINVAL;
3411 return gpiod_get_array_value_complex(true, true, array_size,
3412 desc_array, array_info,
3413 value_bitmap);
3414 }
3415 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3416
3417 /**
3418 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3419 * @array_size: number of elements in the descriptor array / value bitmap
3420 * @desc_array: array of GPIO descriptors whose values will be read
3421 * @array_info: information on applicability of fast bitmap processing path
3422 * @value_bitmap: bitmap to store the read values
3423 *
3424 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3425 * into account. Return 0 in case of success, else an error code.
3426 *
3427 * This function is to be called from contexts that can sleep.
3428 */
gpiod_get_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3429 int gpiod_get_array_value_cansleep(unsigned int array_size,
3430 struct gpio_desc **desc_array,
3431 struct gpio_array *array_info,
3432 unsigned long *value_bitmap)
3433 {
3434 might_sleep_if(extra_checks);
3435 if (!desc_array)
3436 return -EINVAL;
3437 return gpiod_get_array_value_complex(false, true, array_size,
3438 desc_array, array_info,
3439 value_bitmap);
3440 }
3441 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3442
3443 /**
3444 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3445 * @desc: gpio whose value will be assigned
3446 * @value: value to assign
3447 *
3448 * Set the raw value of the GPIO, i.e. the value of its physical line without
3449 * regard for its ACTIVE_LOW status.
3450 *
3451 * This function is to be called from contexts that can sleep.
3452 */
gpiod_set_raw_value_cansleep(struct gpio_desc * desc,int value)3453 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3454 {
3455 might_sleep_if(extra_checks);
3456 VALIDATE_DESC_VOID(desc);
3457 gpiod_set_raw_value_commit(desc, value);
3458 }
3459 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3460
3461 /**
3462 * gpiod_set_value_cansleep() - assign a gpio's value
3463 * @desc: gpio whose value will be assigned
3464 * @value: value to assign
3465 *
3466 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3467 * account
3468 *
3469 * This function is to be called from contexts that can sleep.
3470 */
gpiod_set_value_cansleep(struct gpio_desc * desc,int value)3471 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3472 {
3473 might_sleep_if(extra_checks);
3474 VALIDATE_DESC_VOID(desc);
3475 gpiod_set_value_nocheck(desc, value);
3476 }
3477 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3478
3479 /**
3480 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3481 * @array_size: number of elements in the descriptor array / value bitmap
3482 * @desc_array: array of GPIO descriptors whose values will be assigned
3483 * @array_info: information on applicability of fast bitmap processing path
3484 * @value_bitmap: bitmap of values to assign
3485 *
3486 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3487 * without regard for their ACTIVE_LOW status.
3488 *
3489 * This function is to be called from contexts that can sleep.
3490 */
gpiod_set_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3491 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3492 struct gpio_desc **desc_array,
3493 struct gpio_array *array_info,
3494 unsigned long *value_bitmap)
3495 {
3496 might_sleep_if(extra_checks);
3497 if (!desc_array)
3498 return -EINVAL;
3499 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3500 array_info, value_bitmap);
3501 }
3502 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3503
3504 /**
3505 * gpiod_add_lookup_tables() - register GPIO device consumers
3506 * @tables: list of tables of consumers to register
3507 * @n: number of tables in the list
3508 */
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)3509 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3510 {
3511 unsigned int i;
3512
3513 mutex_lock(&gpio_lookup_lock);
3514
3515 for (i = 0; i < n; i++)
3516 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3517
3518 mutex_unlock(&gpio_lookup_lock);
3519 }
3520
3521 /**
3522 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3523 * @array_size: number of elements in the descriptor array / value bitmap
3524 * @desc_array: array of GPIO descriptors whose values will be assigned
3525 * @array_info: information on applicability of fast bitmap processing path
3526 * @value_bitmap: bitmap of values to assign
3527 *
3528 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3529 * into account.
3530 *
3531 * This function is to be called from contexts that can sleep.
3532 */
gpiod_set_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3533 int gpiod_set_array_value_cansleep(unsigned int array_size,
3534 struct gpio_desc **desc_array,
3535 struct gpio_array *array_info,
3536 unsigned long *value_bitmap)
3537 {
3538 might_sleep_if(extra_checks);
3539 if (!desc_array)
3540 return -EINVAL;
3541 return gpiod_set_array_value_complex(false, true, array_size,
3542 desc_array, array_info,
3543 value_bitmap);
3544 }
3545 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3546
3547 /**
3548 * gpiod_add_lookup_table() - register GPIO device consumers
3549 * @table: table of consumers to register
3550 */
gpiod_add_lookup_table(struct gpiod_lookup_table * table)3551 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3552 {
3553 mutex_lock(&gpio_lookup_lock);
3554
3555 list_add_tail(&table->list, &gpio_lookup_list);
3556
3557 mutex_unlock(&gpio_lookup_lock);
3558 }
3559 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3560
3561 /**
3562 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3563 * @table: table of consumers to unregister
3564 */
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)3565 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3566 {
3567 /* Nothing to remove */
3568 if (!table)
3569 return;
3570
3571 mutex_lock(&gpio_lookup_lock);
3572
3573 list_del(&table->list);
3574
3575 mutex_unlock(&gpio_lookup_lock);
3576 }
3577 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3578
3579 /**
3580 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3581 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3582 */
gpiod_add_hogs(struct gpiod_hog * hogs)3583 void gpiod_add_hogs(struct gpiod_hog *hogs)
3584 {
3585 struct gpio_chip *gc;
3586 struct gpiod_hog *hog;
3587
3588 mutex_lock(&gpio_machine_hogs_mutex);
3589
3590 for (hog = &hogs[0]; hog->chip_label; hog++) {
3591 list_add_tail(&hog->list, &gpio_machine_hogs);
3592
3593 /*
3594 * The chip may have been registered earlier, so check if it
3595 * exists and, if so, try to hog the line now.
3596 */
3597 gc = find_chip_by_name(hog->chip_label);
3598 if (gc)
3599 gpiochip_machine_hog(gc, hog);
3600 }
3601
3602 mutex_unlock(&gpio_machine_hogs_mutex);
3603 }
3604 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3605
gpiod_find_lookup_table(struct device * dev)3606 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3607 {
3608 const char *dev_id = dev ? dev_name(dev) : NULL;
3609 struct gpiod_lookup_table *table;
3610
3611 mutex_lock(&gpio_lookup_lock);
3612
3613 list_for_each_entry(table, &gpio_lookup_list, list) {
3614 if (table->dev_id && dev_id) {
3615 /*
3616 * Valid strings on both ends, must be identical to have
3617 * a match
3618 */
3619 if (!strcmp(table->dev_id, dev_id))
3620 goto found;
3621 } else {
3622 /*
3623 * One of the pointers is NULL, so both must be to have
3624 * a match
3625 */
3626 if (dev_id == table->dev_id)
3627 goto found;
3628 }
3629 }
3630 table = NULL;
3631
3632 found:
3633 mutex_unlock(&gpio_lookup_lock);
3634 return table;
3635 }
3636
gpiod_find(struct device * dev,const char * con_id,unsigned int idx,unsigned long * flags)3637 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3638 unsigned int idx, unsigned long *flags)
3639 {
3640 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3641 struct gpiod_lookup_table *table;
3642 struct gpiod_lookup *p;
3643
3644 table = gpiod_find_lookup_table(dev);
3645 if (!table)
3646 return desc;
3647
3648 for (p = &table->table[0]; p->key; p++) {
3649 struct gpio_chip *gc;
3650
3651 /* idx must always match exactly */
3652 if (p->idx != idx)
3653 continue;
3654
3655 /* If the lookup entry has a con_id, require exact match */
3656 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3657 continue;
3658
3659 if (p->chip_hwnum == U16_MAX) {
3660 desc = gpio_name_to_desc(p->key);
3661 if (desc) {
3662 *flags = p->flags;
3663 return desc;
3664 }
3665
3666 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3667 p->key);
3668 return ERR_PTR(-EPROBE_DEFER);
3669 }
3670
3671 gc = find_chip_by_name(p->key);
3672
3673 if (!gc) {
3674 /*
3675 * As the lookup table indicates a chip with
3676 * p->key should exist, assume it may
3677 * still appear later and let the interested
3678 * consumer be probed again or let the Deferred
3679 * Probe infrastructure handle the error.
3680 */
3681 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3682 p->key);
3683 return ERR_PTR(-EPROBE_DEFER);
3684 }
3685
3686 if (gc->ngpio <= p->chip_hwnum) {
3687 dev_err(dev,
3688 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3689 idx, p->chip_hwnum, gc->ngpio - 1,
3690 gc->label);
3691 return ERR_PTR(-EINVAL);
3692 }
3693
3694 desc = gpiochip_get_desc(gc, p->chip_hwnum);
3695 *flags = p->flags;
3696
3697 return desc;
3698 }
3699
3700 return desc;
3701 }
3702
platform_gpio_count(struct device * dev,const char * con_id)3703 static int platform_gpio_count(struct device *dev, const char *con_id)
3704 {
3705 struct gpiod_lookup_table *table;
3706 struct gpiod_lookup *p;
3707 unsigned int count = 0;
3708
3709 table = gpiod_find_lookup_table(dev);
3710 if (!table)
3711 return -ENOENT;
3712
3713 for (p = &table->table[0]; p->key; p++) {
3714 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3715 (!con_id && !p->con_id))
3716 count++;
3717 }
3718 if (!count)
3719 return -ENOENT;
3720
3721 return count;
3722 }
3723
3724 /**
3725 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3726 * @fwnode: handle of the firmware node
3727 * @con_id: function within the GPIO consumer
3728 * @index: index of the GPIO to obtain for the consumer
3729 * @flags: GPIO initialization flags
3730 * @label: label to attach to the requested GPIO
3731 *
3732 * This function can be used for drivers that get their configuration
3733 * from opaque firmware.
3734 *
3735 * The function properly finds the corresponding GPIO using whatever is the
3736 * underlying firmware interface and then makes sure that the GPIO
3737 * descriptor is requested before it is returned to the caller.
3738 *
3739 * Returns:
3740 * On successful request the GPIO pin is configured in accordance with
3741 * provided @flags.
3742 *
3743 * In case of error an ERR_PTR() is returned.
3744 */
fwnode_gpiod_get_index(struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)3745 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3746 const char *con_id, int index,
3747 enum gpiod_flags flags,
3748 const char *label)
3749 {
3750 struct gpio_desc *desc;
3751 char prop_name[32]; /* 32 is max size of property name */
3752 unsigned int i;
3753
3754 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3755 if (con_id)
3756 snprintf(prop_name, sizeof(prop_name), "%s-%s",
3757 con_id, gpio_suffixes[i]);
3758 else
3759 snprintf(prop_name, sizeof(prop_name), "%s",
3760 gpio_suffixes[i]);
3761
3762 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3763 label);
3764 if (!gpiod_not_found(desc))
3765 break;
3766 }
3767
3768 return desc;
3769 }
3770 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3771
3772 /**
3773 * gpiod_count - return the number of GPIOs associated with a device / function
3774 * or -ENOENT if no GPIO has been assigned to the requested function
3775 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3776 * @con_id: function within the GPIO consumer
3777 */
gpiod_count(struct device * dev,const char * con_id)3778 int gpiod_count(struct device *dev, const char *con_id)
3779 {
3780 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3781 int count = -ENOENT;
3782
3783 if (is_of_node(fwnode))
3784 count = of_gpio_get_count(dev, con_id);
3785 else if (is_acpi_node(fwnode))
3786 count = acpi_gpio_count(dev, con_id);
3787
3788 if (count < 0)
3789 count = platform_gpio_count(dev, con_id);
3790
3791 return count;
3792 }
3793 EXPORT_SYMBOL_GPL(gpiod_count);
3794
3795 /**
3796 * gpiod_get - obtain a GPIO for a given GPIO function
3797 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3798 * @con_id: function within the GPIO consumer
3799 * @flags: optional GPIO initialization flags
3800 *
3801 * Return the GPIO descriptor corresponding to the function con_id of device
3802 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3803 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3804 */
gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)3805 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3806 enum gpiod_flags flags)
3807 {
3808 return gpiod_get_index(dev, con_id, 0, flags);
3809 }
3810 EXPORT_SYMBOL_GPL(gpiod_get);
3811
3812 /**
3813 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3814 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3815 * @con_id: function within the GPIO consumer
3816 * @flags: optional GPIO initialization flags
3817 *
3818 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3819 * the requested function it will return NULL. This is convenient for drivers
3820 * that need to handle optional GPIOs.
3821 */
gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)3822 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3823 const char *con_id,
3824 enum gpiod_flags flags)
3825 {
3826 return gpiod_get_index_optional(dev, con_id, 0, flags);
3827 }
3828 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3829
3830
3831 /**
3832 * gpiod_configure_flags - helper function to configure a given GPIO
3833 * @desc: gpio whose value will be assigned
3834 * @con_id: function within the GPIO consumer
3835 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3836 * of_find_gpio() or of_get_gpio_hog()
3837 * @dflags: gpiod_flags - optional GPIO initialization flags
3838 *
3839 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3840 * requested function and/or index, or another IS_ERR() code if an error
3841 * occurred while trying to acquire the GPIO.
3842 */
gpiod_configure_flags(struct gpio_desc * desc,const char * con_id,unsigned long lflags,enum gpiod_flags dflags)3843 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3844 unsigned long lflags, enum gpiod_flags dflags)
3845 {
3846 int ret;
3847
3848 if (lflags & GPIO_ACTIVE_LOW)
3849 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3850
3851 if (lflags & GPIO_OPEN_DRAIN)
3852 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3853 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3854 /*
3855 * This enforces open drain mode from the consumer side.
3856 * This is necessary for some busses like I2C, but the lookup
3857 * should *REALLY* have specified them as open drain in the
3858 * first place, so print a little warning here.
3859 */
3860 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3861 gpiod_warn(desc,
3862 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3863 }
3864
3865 if (lflags & GPIO_OPEN_SOURCE)
3866 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3867
3868 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3869 gpiod_err(desc,
3870 "both pull-up and pull-down enabled, invalid configuration\n");
3871 return -EINVAL;
3872 }
3873
3874 if (lflags & GPIO_PULL_UP)
3875 set_bit(FLAG_PULL_UP, &desc->flags);
3876 else if (lflags & GPIO_PULL_DOWN)
3877 set_bit(FLAG_PULL_DOWN, &desc->flags);
3878
3879 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3880 if (ret < 0)
3881 return ret;
3882
3883 /* No particular flag request, return here... */
3884 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3885 gpiod_dbg(desc, "no flags found for %s\n", con_id);
3886 return 0;
3887 }
3888
3889 /* Process flags */
3890 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3891 ret = gpiod_direction_output(desc,
3892 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3893 else
3894 ret = gpiod_direction_input(desc);
3895
3896 return ret;
3897 }
3898
3899 /**
3900 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3901 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3902 * @con_id: function within the GPIO consumer
3903 * @idx: index of the GPIO to obtain in the consumer
3904 * @flags: optional GPIO initialization flags
3905 *
3906 * This variant of gpiod_get() allows to access GPIOs other than the first
3907 * defined one for functions that define several GPIOs.
3908 *
3909 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3910 * requested function and/or index, or another IS_ERR() code if an error
3911 * occurred while trying to acquire the GPIO.
3912 */
gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)3913 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3914 const char *con_id,
3915 unsigned int idx,
3916 enum gpiod_flags flags)
3917 {
3918 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3919 struct gpio_desc *desc = NULL;
3920 int ret;
3921 /* Maybe we have a device name, maybe not */
3922 const char *devname = dev ? dev_name(dev) : "?";
3923 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3924
3925 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3926
3927 /* Using device tree? */
3928 if (is_of_node(fwnode)) {
3929 dev_dbg(dev, "using device tree for GPIO lookup\n");
3930 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3931 } else if (is_acpi_node(fwnode)) {
3932 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3933 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3934 }
3935
3936 /*
3937 * Either we are not using DT or ACPI, or their lookup did not return
3938 * a result. In that case, use platform lookup as a fallback.
3939 */
3940 if (!desc || gpiod_not_found(desc)) {
3941 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3942 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3943 }
3944
3945 if (IS_ERR(desc)) {
3946 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3947 return desc;
3948 }
3949
3950 /*
3951 * If a connection label was passed use that, else attempt to use
3952 * the device name as label
3953 */
3954 ret = gpiod_request(desc, con_id ? con_id : devname);
3955 if (ret) {
3956 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
3957 /*
3958 * This happens when there are several consumers for
3959 * the same GPIO line: we just return here without
3960 * further initialization. It is a bit if a hack.
3961 * This is necessary to support fixed regulators.
3962 *
3963 * FIXME: Make this more sane and safe.
3964 */
3965 dev_info(dev, "nonexclusive access to GPIO for %s\n",
3966 con_id ? con_id : devname);
3967 return desc;
3968 } else {
3969 return ERR_PTR(ret);
3970 }
3971 }
3972
3973 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3974 if (ret < 0) {
3975 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3976 gpiod_put(desc);
3977 return ERR_PTR(ret);
3978 }
3979
3980 blocking_notifier_call_chain(&desc->gdev->notifier,
3981 GPIOLINE_CHANGED_REQUESTED, desc);
3982
3983 return desc;
3984 }
3985 EXPORT_SYMBOL_GPL(gpiod_get_index);
3986
3987 /**
3988 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3989 * @fwnode: handle of the firmware node
3990 * @propname: name of the firmware property representing the GPIO
3991 * @index: index of the GPIO to obtain for the consumer
3992 * @dflags: GPIO initialization flags
3993 * @label: label to attach to the requested GPIO
3994 *
3995 * This function can be used for drivers that get their configuration
3996 * from opaque firmware.
3997 *
3998 * The function properly finds the corresponding GPIO using whatever is the
3999 * underlying firmware interface and then makes sure that the GPIO
4000 * descriptor is requested before it is returned to the caller.
4001 *
4002 * Returns:
4003 * On successful request the GPIO pin is configured in accordance with
4004 * provided @dflags.
4005 *
4006 * In case of error an ERR_PTR() is returned.
4007 */
fwnode_get_named_gpiod(struct fwnode_handle * fwnode,const char * propname,int index,enum gpiod_flags dflags,const char * label)4008 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4009 const char *propname, int index,
4010 enum gpiod_flags dflags,
4011 const char *label)
4012 {
4013 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4014 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4015 int ret;
4016
4017 if (is_of_node(fwnode)) {
4018 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4019 propname, index,
4020 dflags,
4021 label);
4022 return desc;
4023 } else if (is_acpi_node(fwnode)) {
4024 struct acpi_gpio_info info;
4025
4026 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4027 if (IS_ERR(desc))
4028 return desc;
4029
4030 acpi_gpio_update_gpiod_flags(&dflags, &info);
4031 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4032 } else
4033 return ERR_PTR(-EINVAL);
4034
4035 /* Currently only ACPI takes this path */
4036 ret = gpiod_request(desc, label);
4037 if (ret)
4038 return ERR_PTR(ret);
4039
4040 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4041 if (ret < 0) {
4042 gpiod_put(desc);
4043 return ERR_PTR(ret);
4044 }
4045
4046 blocking_notifier_call_chain(&desc->gdev->notifier,
4047 GPIOLINE_CHANGED_REQUESTED, desc);
4048
4049 return desc;
4050 }
4051 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4052
4053 /**
4054 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4055 * function
4056 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4057 * @con_id: function within the GPIO consumer
4058 * @index: index of the GPIO to obtain in the consumer
4059 * @flags: optional GPIO initialization flags
4060 *
4061 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4062 * specified index was assigned to the requested function it will return NULL.
4063 * This is convenient for drivers that need to handle optional GPIOs.
4064 */
gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)4065 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4066 const char *con_id,
4067 unsigned int index,
4068 enum gpiod_flags flags)
4069 {
4070 struct gpio_desc *desc;
4071
4072 desc = gpiod_get_index(dev, con_id, index, flags);
4073 if (gpiod_not_found(desc))
4074 return NULL;
4075
4076 return desc;
4077 }
4078 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4079
4080 /**
4081 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4082 * @desc: gpio whose value will be assigned
4083 * @name: gpio line name
4084 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4085 * of_find_gpio() or of_get_gpio_hog()
4086 * @dflags: gpiod_flags - optional GPIO initialization flags
4087 */
gpiod_hog(struct gpio_desc * desc,const char * name,unsigned long lflags,enum gpiod_flags dflags)4088 int gpiod_hog(struct gpio_desc *desc, const char *name,
4089 unsigned long lflags, enum gpiod_flags dflags)
4090 {
4091 struct gpio_chip *gc;
4092 struct gpio_desc *local_desc;
4093 int hwnum;
4094 int ret;
4095
4096 gc = gpiod_to_chip(desc);
4097 hwnum = gpio_chip_hwgpio(desc);
4098
4099 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4100 lflags, dflags);
4101 if (IS_ERR(local_desc)) {
4102 ret = PTR_ERR(local_desc);
4103 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4104 name, gc->label, hwnum, ret);
4105 return ret;
4106 }
4107
4108 /* Mark GPIO as hogged so it can be identified and removed later */
4109 set_bit(FLAG_IS_HOGGED, &desc->flags);
4110
4111 gpiod_info(desc, "hogged as %s%s\n",
4112 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4113 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4114 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4115
4116 return 0;
4117 }
4118
4119 /**
4120 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4121 * @gc: gpio chip to act on
4122 */
gpiochip_free_hogs(struct gpio_chip * gc)4123 static void gpiochip_free_hogs(struct gpio_chip *gc)
4124 {
4125 int id;
4126
4127 for (id = 0; id < gc->ngpio; id++) {
4128 if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
4129 gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
4130 }
4131 }
4132
4133 /**
4134 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4135 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4136 * @con_id: function within the GPIO consumer
4137 * @flags: optional GPIO initialization flags
4138 *
4139 * This function acquires all the GPIOs defined under a given function.
4140 *
4141 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4142 * no GPIO has been assigned to the requested function, or another IS_ERR()
4143 * code if an error occurred while trying to acquire the GPIOs.
4144 */
gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)4145 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4146 const char *con_id,
4147 enum gpiod_flags flags)
4148 {
4149 struct gpio_desc *desc;
4150 struct gpio_descs *descs;
4151 struct gpio_array *array_info = NULL;
4152 struct gpio_chip *gc;
4153 int count, bitmap_size;
4154
4155 count = gpiod_count(dev, con_id);
4156 if (count < 0)
4157 return ERR_PTR(count);
4158
4159 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4160 if (!descs)
4161 return ERR_PTR(-ENOMEM);
4162
4163 for (descs->ndescs = 0; descs->ndescs < count; ) {
4164 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4165 if (IS_ERR(desc)) {
4166 gpiod_put_array(descs);
4167 return ERR_CAST(desc);
4168 }
4169
4170 descs->desc[descs->ndescs] = desc;
4171
4172 gc = gpiod_to_chip(desc);
4173 /*
4174 * If pin hardware number of array member 0 is also 0, select
4175 * its chip as a candidate for fast bitmap processing path.
4176 */
4177 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4178 struct gpio_descs *array;
4179
4180 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4181 gc->ngpio : count);
4182
4183 array = kzalloc(struct_size(descs, desc, count) +
4184 struct_size(array_info, invert_mask,
4185 3 * bitmap_size), GFP_KERNEL);
4186 if (!array) {
4187 gpiod_put_array(descs);
4188 return ERR_PTR(-ENOMEM);
4189 }
4190
4191 memcpy(array, descs,
4192 struct_size(descs, desc, descs->ndescs + 1));
4193 kfree(descs);
4194
4195 descs = array;
4196 array_info = (void *)(descs->desc + count);
4197 array_info->get_mask = array_info->invert_mask +
4198 bitmap_size;
4199 array_info->set_mask = array_info->get_mask +
4200 bitmap_size;
4201
4202 array_info->desc = descs->desc;
4203 array_info->size = count;
4204 array_info->chip = gc;
4205 bitmap_set(array_info->get_mask, descs->ndescs,
4206 count - descs->ndescs);
4207 bitmap_set(array_info->set_mask, descs->ndescs,
4208 count - descs->ndescs);
4209 descs->info = array_info;
4210 }
4211 /* Unmark array members which don't belong to the 'fast' chip */
4212 if (array_info && array_info->chip != gc) {
4213 __clear_bit(descs->ndescs, array_info->get_mask);
4214 __clear_bit(descs->ndescs, array_info->set_mask);
4215 }
4216 /*
4217 * Detect array members which belong to the 'fast' chip
4218 * but their pins are not in hardware order.
4219 */
4220 else if (array_info &&
4221 gpio_chip_hwgpio(desc) != descs->ndescs) {
4222 /*
4223 * Don't use fast path if all array members processed so
4224 * far belong to the same chip as this one but its pin
4225 * hardware number is different from its array index.
4226 */
4227 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4228 array_info = NULL;
4229 } else {
4230 __clear_bit(descs->ndescs,
4231 array_info->get_mask);
4232 __clear_bit(descs->ndescs,
4233 array_info->set_mask);
4234 }
4235 } else if (array_info) {
4236 /* Exclude open drain or open source from fast output */
4237 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4238 gpiochip_line_is_open_source(gc, descs->ndescs))
4239 __clear_bit(descs->ndescs,
4240 array_info->set_mask);
4241 /* Identify 'fast' pins which require invertion */
4242 if (gpiod_is_active_low(desc))
4243 __set_bit(descs->ndescs,
4244 array_info->invert_mask);
4245 }
4246
4247 descs->ndescs++;
4248 }
4249 if (array_info)
4250 dev_dbg(dev,
4251 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4252 array_info->chip->label, array_info->size,
4253 *array_info->get_mask, *array_info->set_mask,
4254 *array_info->invert_mask);
4255 return descs;
4256 }
4257 EXPORT_SYMBOL_GPL(gpiod_get_array);
4258
4259 /**
4260 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4261 * function
4262 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4263 * @con_id: function within the GPIO consumer
4264 * @flags: optional GPIO initialization flags
4265 *
4266 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4267 * assigned to the requested function it will return NULL.
4268 */
gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4269 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4270 const char *con_id,
4271 enum gpiod_flags flags)
4272 {
4273 struct gpio_descs *descs;
4274
4275 descs = gpiod_get_array(dev, con_id, flags);
4276 if (gpiod_not_found(descs))
4277 return NULL;
4278
4279 return descs;
4280 }
4281 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4282
4283 /**
4284 * gpiod_put - dispose of a GPIO descriptor
4285 * @desc: GPIO descriptor to dispose of
4286 *
4287 * No descriptor can be used after gpiod_put() has been called on it.
4288 */
gpiod_put(struct gpio_desc * desc)4289 void gpiod_put(struct gpio_desc *desc)
4290 {
4291 if (desc)
4292 gpiod_free(desc);
4293 }
4294 EXPORT_SYMBOL_GPL(gpiod_put);
4295
4296 /**
4297 * gpiod_put_array - dispose of multiple GPIO descriptors
4298 * @descs: struct gpio_descs containing an array of descriptors
4299 */
gpiod_put_array(struct gpio_descs * descs)4300 void gpiod_put_array(struct gpio_descs *descs)
4301 {
4302 unsigned int i;
4303
4304 for (i = 0; i < descs->ndescs; i++)
4305 gpiod_put(descs->desc[i]);
4306
4307 kfree(descs);
4308 }
4309 EXPORT_SYMBOL_GPL(gpiod_put_array);
4310
4311
gpio_bus_match(struct device * dev,struct device_driver * drv)4312 static int gpio_bus_match(struct device *dev, struct device_driver *drv)
4313 {
4314 struct fwnode_handle *fwnode = dev_fwnode(dev);
4315
4316 /*
4317 * Only match if the fwnode doesn't already have a proper struct device
4318 * created for it.
4319 */
4320 if (fwnode && fwnode->dev != dev)
4321 return 0;
4322 return 1;
4323 }
4324
gpio_stub_drv_probe(struct device * dev)4325 static int gpio_stub_drv_probe(struct device *dev)
4326 {
4327 /*
4328 * The DT node of some GPIO chips have a "compatible" property, but
4329 * never have a struct device added and probed by a driver to register
4330 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4331 * the consumers of the GPIO chip to get probe deferred forever because
4332 * they will be waiting for a device associated with the GPIO chip
4333 * firmware node to get added and bound to a driver.
4334 *
4335 * To allow these consumers to probe, we associate the struct
4336 * gpio_device of the GPIO chip with the firmware node and then simply
4337 * bind it to this stub driver.
4338 */
4339 return 0;
4340 }
4341
4342 static struct device_driver gpio_stub_drv = {
4343 .name = "gpio_stub_drv",
4344 .bus = &gpio_bus_type,
4345 .probe = gpio_stub_drv_probe,
4346 };
4347
gpiolib_dev_init(void)4348 static int __init gpiolib_dev_init(void)
4349 {
4350 int ret;
4351
4352 /* Register GPIO sysfs bus */
4353 ret = bus_register(&gpio_bus_type);
4354 if (ret < 0) {
4355 pr_err("gpiolib: could not register GPIO bus type\n");
4356 return ret;
4357 }
4358
4359 ret = driver_register(&gpio_stub_drv);
4360 if (ret < 0) {
4361 pr_err("gpiolib: could not register GPIO stub driver\n");
4362 bus_unregister(&gpio_bus_type);
4363 return ret;
4364 }
4365
4366 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4367 if (ret < 0) {
4368 pr_err("gpiolib: failed to allocate char dev region\n");
4369 driver_unregister(&gpio_stub_drv);
4370 bus_unregister(&gpio_bus_type);
4371 return ret;
4372 }
4373
4374 gpiolib_initialized = true;
4375 gpiochip_setup_devs();
4376
4377 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4378 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4379 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4380
4381 return ret;
4382 }
4383 core_initcall(gpiolib_dev_init);
4384
4385 #ifdef CONFIG_DEBUG_FS
4386
gpiolib_dbg_show(struct seq_file * s,struct gpio_device * gdev)4387 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4388 {
4389 unsigned i;
4390 struct gpio_chip *gc = gdev->chip;
4391 unsigned gpio = gdev->base;
4392 struct gpio_desc *gdesc = &gdev->descs[0];
4393 bool is_out;
4394 bool is_irq;
4395 bool active_low;
4396
4397 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4398 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4399 if (gdesc->name) {
4400 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4401 gpio, gdesc->name);
4402 }
4403 continue;
4404 }
4405
4406 gpiod_get_direction(gdesc);
4407 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4408 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4409 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4410 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4411 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4412 is_out ? "out" : "in ",
4413 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
4414 is_irq ? "IRQ " : "",
4415 active_low ? "ACTIVE LOW" : "");
4416 seq_printf(s, "\n");
4417 }
4418 }
4419
gpiolib_seq_start(struct seq_file * s,loff_t * pos)4420 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4421 {
4422 unsigned long flags;
4423 struct gpio_device *gdev = NULL;
4424 loff_t index = *pos;
4425
4426 s->private = "";
4427
4428 spin_lock_irqsave(&gpio_lock, flags);
4429 list_for_each_entry(gdev, &gpio_devices, list)
4430 if (index-- == 0) {
4431 spin_unlock_irqrestore(&gpio_lock, flags);
4432 return gdev;
4433 }
4434 spin_unlock_irqrestore(&gpio_lock, flags);
4435
4436 return NULL;
4437 }
4438
gpiolib_seq_next(struct seq_file * s,void * v,loff_t * pos)4439 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4440 {
4441 unsigned long flags;
4442 struct gpio_device *gdev = v;
4443 void *ret = NULL;
4444
4445 spin_lock_irqsave(&gpio_lock, flags);
4446 if (list_is_last(&gdev->list, &gpio_devices))
4447 ret = NULL;
4448 else
4449 ret = list_entry(gdev->list.next, struct gpio_device, list);
4450 spin_unlock_irqrestore(&gpio_lock, flags);
4451
4452 s->private = "\n";
4453 ++*pos;
4454
4455 return ret;
4456 }
4457
gpiolib_seq_stop(struct seq_file * s,void * v)4458 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4459 {
4460 }
4461
gpiolib_seq_show(struct seq_file * s,void * v)4462 static int gpiolib_seq_show(struct seq_file *s, void *v)
4463 {
4464 struct gpio_device *gdev = v;
4465 struct gpio_chip *gc = gdev->chip;
4466 struct device *parent;
4467
4468 if (!gc) {
4469 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4470 dev_name(&gdev->dev));
4471 return 0;
4472 }
4473
4474 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4475 dev_name(&gdev->dev),
4476 gdev->base, gdev->base + gdev->ngpio - 1);
4477 parent = gc->parent;
4478 if (parent)
4479 seq_printf(s, ", parent: %s/%s",
4480 parent->bus ? parent->bus->name : "no-bus",
4481 dev_name(parent));
4482 if (gc->label)
4483 seq_printf(s, ", %s", gc->label);
4484 if (gc->can_sleep)
4485 seq_printf(s, ", can sleep");
4486 seq_printf(s, ":\n");
4487
4488 if (gc->dbg_show)
4489 gc->dbg_show(s, gc);
4490 else
4491 gpiolib_dbg_show(s, gdev);
4492
4493 return 0;
4494 }
4495
4496 static const struct seq_operations gpiolib_sops = {
4497 .start = gpiolib_seq_start,
4498 .next = gpiolib_seq_next,
4499 .stop = gpiolib_seq_stop,
4500 .show = gpiolib_seq_show,
4501 };
4502 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4503
gpiolib_debugfs_init(void)4504 static int __init gpiolib_debugfs_init(void)
4505 {
4506 /* /sys/kernel/debug/gpio */
4507 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4508 return 0;
4509 }
4510 subsys_initcall(gpiolib_debugfs_init);
4511
4512 #endif /* DEBUG_FS */
4513