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 init_rwsem(&gdev->sem);
731
732 #ifdef CONFIG_PINCTRL
733 INIT_LIST_HEAD(&gdev->pin_ranges);
734 #endif
735
736 if (gc->names)
737 ret = gpiochip_set_desc_names(gc);
738 else
739 ret = devprop_gpiochip_set_names(gc);
740 if (ret)
741 goto err_remove_from_list;
742
743 ret = gpiochip_alloc_valid_mask(gc);
744 if (ret)
745 goto err_remove_from_list;
746
747 ret = of_gpiochip_add(gc);
748 if (ret)
749 goto err_free_gpiochip_mask;
750
751 ret = gpiochip_init_valid_mask(gc);
752 if (ret)
753 goto err_remove_of_chip;
754
755 for (i = 0; i < gc->ngpio; i++) {
756 struct gpio_desc *desc = &gdev->descs[i];
757
758 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
759 assign_bit(FLAG_IS_OUT,
760 &desc->flags, !gc->get_direction(gc, i));
761 } else {
762 assign_bit(FLAG_IS_OUT,
763 &desc->flags, !gc->direction_input);
764 }
765 }
766
767 ret = gpiochip_add_pin_ranges(gc);
768 if (ret)
769 goto err_remove_of_chip;
770
771 acpi_gpiochip_add(gc);
772
773 machine_gpiochip_add(gc);
774
775 ret = gpiochip_irqchip_init_valid_mask(gc);
776 if (ret)
777 goto err_free_hogs;
778
779 ret = gpiochip_irqchip_init_hw(gc);
780 if (ret)
781 goto err_remove_irqchip_mask;
782
783 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
784 if (ret)
785 goto err_remove_irqchip_mask;
786
787 /*
788 * By first adding the chardev, and then adding the device,
789 * we get a device node entry in sysfs under
790 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
791 * coldplug of device nodes and other udev business.
792 * We can do this only if gpiolib has been initialized.
793 * Otherwise, defer until later.
794 */
795 if (gpiolib_initialized) {
796 ret = gpiochip_setup_dev(gdev);
797 if (ret)
798 goto err_remove_irqchip;
799 }
800 return 0;
801
802 err_remove_irqchip:
803 gpiochip_irqchip_remove(gc);
804 err_remove_irqchip_mask:
805 gpiochip_irqchip_free_valid_mask(gc);
806 err_free_hogs:
807 gpiochip_free_hogs(gc);
808 acpi_gpiochip_remove(gc);
809 gpiochip_remove_pin_ranges(gc);
810 err_remove_of_chip:
811 of_gpiochip_remove(gc);
812 err_free_gpiochip_mask:
813 gpiochip_free_valid_mask(gc);
814 if (gdev->dev.release) {
815 /* release() has been registered by gpiochip_setup_dev() */
816 put_device(&gdev->dev);
817 goto err_print_message;
818 }
819 err_remove_from_list:
820 spin_lock_irqsave(&gpio_lock, flags);
821 list_del(&gdev->list);
822 spin_unlock_irqrestore(&gpio_lock, flags);
823 err_free_label:
824 kfree_const(gdev->label);
825 err_free_descs:
826 kfree(gdev->descs);
827 err_free_dev_name:
828 kfree(dev_name(&gdev->dev));
829 err_free_ida:
830 ida_free(&gpio_ida, gdev->id);
831 err_free_gdev:
832 kfree(gdev);
833 err_print_message:
834 /* failures here can mean systems won't boot... */
835 if (ret != -EPROBE_DEFER) {
836 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
837 base, base + (int)ngpios - 1,
838 gc->label ? : "generic", ret);
839 }
840 return ret;
841 }
842 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
843
844 /**
845 * gpiochip_get_data() - get per-subdriver data for the chip
846 * @gc: GPIO chip
847 *
848 * Returns:
849 * The per-subdriver data for the chip.
850 */
gpiochip_get_data(struct gpio_chip * gc)851 void *gpiochip_get_data(struct gpio_chip *gc)
852 {
853 return gc->gpiodev->data;
854 }
855 EXPORT_SYMBOL_GPL(gpiochip_get_data);
856
857 /**
858 * gpiochip_remove() - unregister a gpio_chip
859 * @gc: the chip to unregister
860 *
861 * A gpio_chip with any GPIOs still requested may not be removed.
862 */
gpiochip_remove(struct gpio_chip * gc)863 void gpiochip_remove(struct gpio_chip *gc)
864 {
865 struct gpio_device *gdev = gc->gpiodev;
866 unsigned long flags;
867 unsigned int i;
868
869 down_write(&gdev->sem);
870
871 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
872 gpiochip_sysfs_unregister(gdev);
873 gpiochip_free_hogs(gc);
874 /* Numb the device, cancelling all outstanding operations */
875 gdev->chip = NULL;
876 gpiochip_irqchip_remove(gc);
877 acpi_gpiochip_remove(gc);
878 of_gpiochip_remove(gc);
879 gpiochip_remove_pin_ranges(gc);
880 gpiochip_free_valid_mask(gc);
881 /*
882 * We accept no more calls into the driver from this point, so
883 * NULL the driver data pointer
884 */
885 gdev->data = NULL;
886
887 spin_lock_irqsave(&gpio_lock, flags);
888 for (i = 0; i < gdev->ngpio; i++) {
889 if (gpiochip_is_requested(gc, i))
890 break;
891 }
892 spin_unlock_irqrestore(&gpio_lock, flags);
893
894 if (i != gdev->ngpio)
895 dev_crit(&gdev->dev,
896 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
897
898 /*
899 * The gpiochip side puts its use of the device to rest here:
900 * if there are no userspace clients, the chardev and device will
901 * be removed, else it will be dangling until the last user is
902 * gone.
903 */
904 gcdev_unregister(gdev);
905 up_write(&gdev->sem);
906 put_device(&gdev->dev);
907 }
908 EXPORT_SYMBOL_GPL(gpiochip_remove);
909
910 /**
911 * gpiochip_find() - iterator for locating a specific gpio_chip
912 * @data: data to pass to match function
913 * @match: Callback function to check gpio_chip
914 *
915 * Similar to bus_find_device. It returns a reference to a gpio_chip as
916 * determined by a user supplied @match callback. The callback should return
917 * 0 if the device doesn't match and non-zero if it does. If the callback is
918 * non-zero, this function will return to the caller and not iterate over any
919 * more gpio_chips.
920 */
gpiochip_find(void * data,int (* match)(struct gpio_chip * gc,void * data))921 struct gpio_chip *gpiochip_find(void *data,
922 int (*match)(struct gpio_chip *gc,
923 void *data))
924 {
925 struct gpio_device *gdev;
926 struct gpio_chip *gc = NULL;
927 unsigned long flags;
928
929 spin_lock_irqsave(&gpio_lock, flags);
930 list_for_each_entry(gdev, &gpio_devices, list)
931 if (gdev->chip && match(gdev->chip, data)) {
932 gc = gdev->chip;
933 break;
934 }
935
936 spin_unlock_irqrestore(&gpio_lock, flags);
937
938 return gc;
939 }
940 EXPORT_SYMBOL_GPL(gpiochip_find);
941
gpiochip_match_name(struct gpio_chip * gc,void * data)942 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
943 {
944 const char *name = data;
945
946 return !strcmp(gc->label, name);
947 }
948
find_chip_by_name(const char * name)949 static struct gpio_chip *find_chip_by_name(const char *name)
950 {
951 return gpiochip_find((void *)name, gpiochip_match_name);
952 }
953
954 #ifdef CONFIG_GPIOLIB_IRQCHIP
955
956 /*
957 * The following is irqchip helper code for gpiochips.
958 */
959
gpiochip_irqchip_init_hw(struct gpio_chip * gc)960 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
961 {
962 struct gpio_irq_chip *girq = &gc->irq;
963
964 if (!girq->init_hw)
965 return 0;
966
967 return girq->init_hw(gc);
968 }
969
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)970 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
971 {
972 struct gpio_irq_chip *girq = &gc->irq;
973
974 if (!girq->init_valid_mask)
975 return 0;
976
977 girq->valid_mask = gpiochip_allocate_mask(gc);
978 if (!girq->valid_mask)
979 return -ENOMEM;
980
981 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
982
983 return 0;
984 }
985
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)986 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
987 {
988 bitmap_free(gc->irq.valid_mask);
989 gc->irq.valid_mask = NULL;
990 }
991
gpiochip_irqchip_irq_valid(const struct gpio_chip * gc,unsigned int offset)992 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
993 unsigned int offset)
994 {
995 if (!gpiochip_line_is_valid(gc, offset))
996 return false;
997 /* No mask means all valid */
998 if (likely(!gc->irq.valid_mask))
999 return true;
1000 return test_bit(offset, gc->irq.valid_mask);
1001 }
1002 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1003
1004 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1005
1006 /**
1007 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1008 * to a gpiochip
1009 * @gc: the gpiochip to set the irqchip hierarchical handler to
1010 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1011 * will then percolate up to the parent
1012 */
gpiochip_set_hierarchical_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip)1013 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1014 struct irq_chip *irqchip)
1015 {
1016 /* DT will deal with mapping each IRQ as we go along */
1017 if (is_of_node(gc->irq.fwnode))
1018 return;
1019
1020 /*
1021 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1022 * irqs upfront instead of dynamically since we don't have the
1023 * dynamic type of allocation that hardware description languages
1024 * provide. Once all GPIO drivers using board files are gone from
1025 * the kernel we can delete this code, but for a transitional period
1026 * it is necessary to keep this around.
1027 */
1028 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1029 int i;
1030 int ret;
1031
1032 for (i = 0; i < gc->ngpio; i++) {
1033 struct irq_fwspec fwspec;
1034 unsigned int parent_hwirq;
1035 unsigned int parent_type;
1036 struct gpio_irq_chip *girq = &gc->irq;
1037
1038 /*
1039 * We call the child to parent translation function
1040 * only to check if the child IRQ is valid or not.
1041 * Just pick the rising edge type here as that is what
1042 * we likely need to support.
1043 */
1044 ret = girq->child_to_parent_hwirq(gc, i,
1045 IRQ_TYPE_EDGE_RISING,
1046 &parent_hwirq,
1047 &parent_type);
1048 if (ret) {
1049 chip_err(gc, "skip set-up on hwirq %d\n",
1050 i);
1051 continue;
1052 }
1053
1054 fwspec.fwnode = gc->irq.fwnode;
1055 /* This is the hwirq for the GPIO line side of things */
1056 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1057 /* Just pick something */
1058 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1059 fwspec.param_count = 2;
1060 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1061 /* just pick something */
1062 -1,
1063 1,
1064 NUMA_NO_NODE,
1065 &fwspec,
1066 false,
1067 NULL);
1068 if (ret < 0) {
1069 chip_err(gc,
1070 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1071 i, parent_hwirq,
1072 ret);
1073 }
1074 }
1075 }
1076
1077 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1078
1079 return;
1080 }
1081
gpiochip_hierarchy_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1082 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1083 struct irq_fwspec *fwspec,
1084 unsigned long *hwirq,
1085 unsigned int *type)
1086 {
1087 /* We support standard DT translation */
1088 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1089 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1090 }
1091
1092 /* This is for board files and others not using DT */
1093 if (is_fwnode_irqchip(fwspec->fwnode)) {
1094 int ret;
1095
1096 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1097 if (ret)
1098 return ret;
1099 WARN_ON(*type == IRQ_TYPE_NONE);
1100 return 0;
1101 }
1102 return -EINVAL;
1103 }
1104
gpiochip_hierarchy_irq_domain_alloc(struct irq_domain * d,unsigned int irq,unsigned int nr_irqs,void * data)1105 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1106 unsigned int irq,
1107 unsigned int nr_irqs,
1108 void *data)
1109 {
1110 struct gpio_chip *gc = d->host_data;
1111 irq_hw_number_t hwirq;
1112 unsigned int type = IRQ_TYPE_NONE;
1113 struct irq_fwspec *fwspec = data;
1114 void *parent_arg;
1115 unsigned int parent_hwirq;
1116 unsigned int parent_type;
1117 struct gpio_irq_chip *girq = &gc->irq;
1118 int ret;
1119
1120 /*
1121 * The nr_irqs parameter is always one except for PCI multi-MSI
1122 * so this should not happen.
1123 */
1124 WARN_ON(nr_irqs != 1);
1125
1126 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1127 if (ret)
1128 return ret;
1129
1130 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1131
1132 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1133 &parent_hwirq, &parent_type);
1134 if (ret) {
1135 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1136 return ret;
1137 }
1138 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1139
1140 /*
1141 * We set handle_bad_irq because the .set_type() should
1142 * always be invoked and set the right type of handler.
1143 */
1144 irq_domain_set_info(d,
1145 irq,
1146 hwirq,
1147 gc->irq.chip,
1148 gc,
1149 girq->handler,
1150 NULL, NULL);
1151 irq_set_probe(irq);
1152
1153 /* This parent only handles asserted level IRQs */
1154 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1155 if (!parent_arg)
1156 return -ENOMEM;
1157
1158 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1159 irq, parent_hwirq);
1160 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1161 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1162 /*
1163 * If the parent irqdomain is msi, the interrupts have already
1164 * been allocated, so the EEXIST is good.
1165 */
1166 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1167 ret = 0;
1168 if (ret)
1169 chip_err(gc,
1170 "failed to allocate parent hwirq %d for hwirq %lu\n",
1171 parent_hwirq, hwirq);
1172
1173 kfree(parent_arg);
1174 return ret;
1175 }
1176
gpiochip_child_offset_to_irq_noop(struct gpio_chip * gc,unsigned int offset)1177 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1178 unsigned int offset)
1179 {
1180 return offset;
1181 }
1182
gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops * ops)1183 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1184 {
1185 ops->activate = gpiochip_irq_domain_activate;
1186 ops->deactivate = gpiochip_irq_domain_deactivate;
1187 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1188 ops->free = irq_domain_free_irqs_common;
1189
1190 /*
1191 * We only allow overriding the translate() function for
1192 * hierarchical chips, and this should only be done if the user
1193 * really need something other than 1:1 translation.
1194 */
1195 if (!ops->translate)
1196 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1197 }
1198
gpiochip_hierarchy_add_domain(struct gpio_chip * gc)1199 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1200 {
1201 if (!gc->irq.child_to_parent_hwirq ||
1202 !gc->irq.fwnode) {
1203 chip_err(gc, "missing irqdomain vital data\n");
1204 return -EINVAL;
1205 }
1206
1207 if (!gc->irq.child_offset_to_irq)
1208 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1209
1210 if (!gc->irq.populate_parent_alloc_arg)
1211 gc->irq.populate_parent_alloc_arg =
1212 gpiochip_populate_parent_fwspec_twocell;
1213
1214 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1215
1216 gc->irq.domain = irq_domain_create_hierarchy(
1217 gc->irq.parent_domain,
1218 0,
1219 gc->ngpio,
1220 gc->irq.fwnode,
1221 &gc->irq.child_irq_domain_ops,
1222 gc);
1223
1224 if (!gc->irq.domain)
1225 return -ENOMEM;
1226
1227 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1228
1229 return 0;
1230 }
1231
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1232 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1233 {
1234 return !!gc->irq.parent_domain;
1235 }
1236
gpiochip_populate_parent_fwspec_twocell(struct gpio_chip * gc,unsigned int parent_hwirq,unsigned int parent_type)1237 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1238 unsigned int parent_hwirq,
1239 unsigned int parent_type)
1240 {
1241 struct irq_fwspec *fwspec;
1242
1243 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1244 if (!fwspec)
1245 return NULL;
1246
1247 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1248 fwspec->param_count = 2;
1249 fwspec->param[0] = parent_hwirq;
1250 fwspec->param[1] = parent_type;
1251
1252 return fwspec;
1253 }
1254 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1255
gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip * gc,unsigned int parent_hwirq,unsigned int parent_type)1256 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1257 unsigned int parent_hwirq,
1258 unsigned int parent_type)
1259 {
1260 struct irq_fwspec *fwspec;
1261
1262 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1263 if (!fwspec)
1264 return NULL;
1265
1266 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1267 fwspec->param_count = 4;
1268 fwspec->param[0] = 0;
1269 fwspec->param[1] = parent_hwirq;
1270 fwspec->param[2] = 0;
1271 fwspec->param[3] = parent_type;
1272
1273 return fwspec;
1274 }
1275 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1276
1277 #else
1278
gpiochip_hierarchy_add_domain(struct gpio_chip * gc)1279 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1280 {
1281 return -EINVAL;
1282 }
1283
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1284 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1285 {
1286 return false;
1287 }
1288
1289 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1290
1291 /**
1292 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1293 * @d: the irqdomain used by this irqchip
1294 * @irq: the global irq number used by this GPIO irqchip irq
1295 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1296 *
1297 * This function will set up the mapping for a certain IRQ line on a
1298 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1299 * stored inside the gpiochip.
1300 */
gpiochip_irq_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)1301 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1302 irq_hw_number_t hwirq)
1303 {
1304 struct gpio_chip *gc = d->host_data;
1305 int ret = 0;
1306
1307 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1308 return -ENXIO;
1309
1310 irq_set_chip_data(irq, gc);
1311 /*
1312 * This lock class tells lockdep that GPIO irqs are in a different
1313 * category than their parents, so it won't report false recursion.
1314 */
1315 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1316 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1317 /* Chips that use nested thread handlers have them marked */
1318 if (gc->irq.threaded)
1319 irq_set_nested_thread(irq, 1);
1320 irq_set_noprobe(irq);
1321
1322 if (gc->irq.num_parents == 1)
1323 ret = irq_set_parent(irq, gc->irq.parents[0]);
1324 else if (gc->irq.map)
1325 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1326
1327 if (ret < 0)
1328 return ret;
1329
1330 /*
1331 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1332 * is passed as default type.
1333 */
1334 if (gc->irq.default_type != IRQ_TYPE_NONE)
1335 irq_set_irq_type(irq, gc->irq.default_type);
1336
1337 return 0;
1338 }
1339 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1340
gpiochip_irq_unmap(struct irq_domain * d,unsigned int irq)1341 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1342 {
1343 struct gpio_chip *gc = d->host_data;
1344
1345 if (gc->irq.threaded)
1346 irq_set_nested_thread(irq, 0);
1347 irq_set_chip_and_handler(irq, NULL, NULL);
1348 irq_set_chip_data(irq, NULL);
1349 }
1350 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1351
1352 static const struct irq_domain_ops gpiochip_domain_ops = {
1353 .map = gpiochip_irq_map,
1354 .unmap = gpiochip_irq_unmap,
1355 /* Virtually all GPIO irqchips are twocell:ed */
1356 .xlate = irq_domain_xlate_twocell,
1357 };
1358
1359 /*
1360 * TODO: move these activate/deactivate in under the hierarchicial
1361 * irqchip implementation as static once SPMI and SSBI (all external
1362 * users) are phased over.
1363 */
1364 /**
1365 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1366 * @domain: The IRQ domain used by this IRQ chip
1367 * @data: Outermost irq_data associated with the IRQ
1368 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1369 *
1370 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1371 * used as the activate function for the &struct irq_domain_ops. The host_data
1372 * for the IRQ domain must be the &struct gpio_chip.
1373 */
gpiochip_irq_domain_activate(struct irq_domain * domain,struct irq_data * data,bool reserve)1374 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1375 struct irq_data *data, bool reserve)
1376 {
1377 struct gpio_chip *gc = domain->host_data;
1378
1379 return gpiochip_lock_as_irq(gc, data->hwirq);
1380 }
1381 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1382
1383 /**
1384 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1385 * @domain: The IRQ domain used by this IRQ chip
1386 * @data: Outermost irq_data associated with the IRQ
1387 *
1388 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1389 * be used as the deactivate function for the &struct irq_domain_ops. The
1390 * host_data for the IRQ domain must be the &struct gpio_chip.
1391 */
gpiochip_irq_domain_deactivate(struct irq_domain * domain,struct irq_data * data)1392 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1393 struct irq_data *data)
1394 {
1395 struct gpio_chip *gc = domain->host_data;
1396
1397 return gpiochip_unlock_as_irq(gc, data->hwirq);
1398 }
1399 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1400
gpiochip_to_irq(struct gpio_chip * gc,unsigned int offset)1401 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1402 {
1403 struct irq_domain *domain = gc->irq.domain;
1404
1405 #ifdef CONFIG_GPIOLIB_IRQCHIP
1406 /*
1407 * Avoid race condition with other code, which tries to lookup
1408 * an IRQ before the irqchip has been properly registered,
1409 * i.e. while gpiochip is still being brought up.
1410 */
1411 if (!gc->irq.initialized)
1412 return -EPROBE_DEFER;
1413 #endif
1414
1415 if (!gpiochip_irqchip_irq_valid(gc, offset))
1416 return -ENXIO;
1417
1418 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1419 if (irq_domain_is_hierarchy(domain)) {
1420 struct irq_fwspec spec;
1421
1422 spec.fwnode = domain->fwnode;
1423 spec.param_count = 2;
1424 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1425 spec.param[1] = IRQ_TYPE_NONE;
1426
1427 return irq_create_fwspec_mapping(&spec);
1428 }
1429 #endif
1430
1431 return irq_create_mapping(domain, offset);
1432 }
1433
gpiochip_irq_reqres(struct irq_data * d)1434 static int gpiochip_irq_reqres(struct irq_data *d)
1435 {
1436 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1437
1438 return gpiochip_reqres_irq(gc, d->hwirq);
1439 }
1440
gpiochip_irq_relres(struct irq_data * d)1441 static void gpiochip_irq_relres(struct irq_data *d)
1442 {
1443 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1444
1445 gpiochip_relres_irq(gc, d->hwirq);
1446 }
1447
gpiochip_irq_mask(struct irq_data * d)1448 static void gpiochip_irq_mask(struct irq_data *d)
1449 {
1450 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1451
1452 if (gc->irq.irq_mask)
1453 gc->irq.irq_mask(d);
1454 gpiochip_disable_irq(gc, d->hwirq);
1455 }
1456
gpiochip_irq_unmask(struct irq_data * d)1457 static void gpiochip_irq_unmask(struct irq_data *d)
1458 {
1459 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1460
1461 gpiochip_enable_irq(gc, d->hwirq);
1462 if (gc->irq.irq_unmask)
1463 gc->irq.irq_unmask(d);
1464 }
1465
gpiochip_irq_enable(struct irq_data * d)1466 static void gpiochip_irq_enable(struct irq_data *d)
1467 {
1468 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1469
1470 gpiochip_enable_irq(gc, d->hwirq);
1471 gc->irq.irq_enable(d);
1472 }
1473
gpiochip_irq_disable(struct irq_data * d)1474 static void gpiochip_irq_disable(struct irq_data *d)
1475 {
1476 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1477
1478 gc->irq.irq_disable(d);
1479 gpiochip_disable_irq(gc, d->hwirq);
1480 }
1481
gpiochip_set_irq_hooks(struct gpio_chip * gc)1482 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1483 {
1484 struct irq_chip *irqchip = gc->irq.chip;
1485
1486 if (!irqchip->irq_request_resources &&
1487 !irqchip->irq_release_resources) {
1488 irqchip->irq_request_resources = gpiochip_irq_reqres;
1489 irqchip->irq_release_resources = gpiochip_irq_relres;
1490 }
1491 if (WARN_ON(gc->irq.irq_enable))
1492 return;
1493 /* Check if the irqchip already has this hook... */
1494 if (irqchip->irq_enable == gpiochip_irq_enable ||
1495 irqchip->irq_mask == gpiochip_irq_mask) {
1496 /*
1497 * ...and if so, give a gentle warning that this is bad
1498 * practice.
1499 */
1500 chip_info(gc,
1501 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1502 return;
1503 }
1504
1505 if (irqchip->irq_disable) {
1506 gc->irq.irq_disable = irqchip->irq_disable;
1507 irqchip->irq_disable = gpiochip_irq_disable;
1508 } else {
1509 gc->irq.irq_mask = irqchip->irq_mask;
1510 irqchip->irq_mask = gpiochip_irq_mask;
1511 }
1512
1513 if (irqchip->irq_enable) {
1514 gc->irq.irq_enable = irqchip->irq_enable;
1515 irqchip->irq_enable = gpiochip_irq_enable;
1516 } else {
1517 gc->irq.irq_unmask = irqchip->irq_unmask;
1518 irqchip->irq_unmask = gpiochip_irq_unmask;
1519 }
1520 }
1521
1522 /**
1523 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1524 * @gc: the GPIO chip to add the IRQ chip to
1525 * @lock_key: lockdep class for IRQ lock
1526 * @request_key: lockdep class for IRQ request
1527 */
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)1528 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1529 struct lock_class_key *lock_key,
1530 struct lock_class_key *request_key)
1531 {
1532 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1533 struct irq_chip *irqchip = gc->irq.chip;
1534 unsigned int type;
1535 unsigned int i;
1536
1537 if (!irqchip)
1538 return 0;
1539
1540 if (gc->irq.parent_handler && gc->can_sleep) {
1541 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1542 return -EINVAL;
1543 }
1544
1545 type = gc->irq.default_type;
1546
1547 /*
1548 * Specifying a default trigger is a terrible idea if DT or ACPI is
1549 * used to configure the interrupts, as you may end up with
1550 * conflicting triggers. Tell the user, and reset to NONE.
1551 */
1552 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1553 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1554 type = IRQ_TYPE_NONE;
1555
1556 if (gc->to_irq)
1557 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1558
1559 gc->to_irq = gpiochip_to_irq;
1560 gc->irq.default_type = type;
1561 gc->irq.lock_key = lock_key;
1562 gc->irq.request_key = request_key;
1563
1564 /* If a parent irqdomain is provided, let's build a hierarchy */
1565 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1566 int ret = gpiochip_hierarchy_add_domain(gc);
1567 if (ret)
1568 return ret;
1569 } else {
1570 /* Some drivers provide custom irqdomain ops */
1571 gc->irq.domain = irq_domain_create_simple(fwnode,
1572 gc->ngpio,
1573 gc->irq.first,
1574 gc->irq.domain_ops ?: &gpiochip_domain_ops,
1575 gc);
1576 if (!gc->irq.domain)
1577 return -EINVAL;
1578 }
1579
1580 if (gc->irq.parent_handler) {
1581 void *data = gc->irq.parent_handler_data ?: gc;
1582
1583 for (i = 0; i < gc->irq.num_parents; i++) {
1584 /*
1585 * The parent IRQ chip is already using the chip_data
1586 * for this IRQ chip, so our callbacks simply use the
1587 * handler_data.
1588 */
1589 irq_set_chained_handler_and_data(gc->irq.parents[i],
1590 gc->irq.parent_handler,
1591 data);
1592 }
1593 }
1594
1595 gpiochip_set_irq_hooks(gc);
1596
1597 /*
1598 * Using barrier() here to prevent compiler from reordering
1599 * gc->irq.initialized before initialization of above
1600 * GPIO chip irq members.
1601 */
1602 barrier();
1603
1604 gc->irq.initialized = true;
1605
1606 acpi_gpiochip_request_interrupts(gc);
1607
1608 return 0;
1609 }
1610
1611 /**
1612 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1613 * @gc: the gpiochip to remove the irqchip from
1614 *
1615 * This is called only from gpiochip_remove()
1616 */
gpiochip_irqchip_remove(struct gpio_chip * gc)1617 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1618 {
1619 struct irq_chip *irqchip = gc->irq.chip;
1620 unsigned int offset;
1621
1622 acpi_gpiochip_free_interrupts(gc);
1623
1624 if (irqchip && gc->irq.parent_handler) {
1625 struct gpio_irq_chip *irq = &gc->irq;
1626 unsigned int i;
1627
1628 for (i = 0; i < irq->num_parents; i++)
1629 irq_set_chained_handler_and_data(irq->parents[i],
1630 NULL, NULL);
1631 }
1632
1633 /* Remove all IRQ mappings and delete the domain */
1634 if (gc->irq.domain) {
1635 unsigned int irq;
1636
1637 for (offset = 0; offset < gc->ngpio; offset++) {
1638 if (!gpiochip_irqchip_irq_valid(gc, offset))
1639 continue;
1640
1641 irq = irq_find_mapping(gc->irq.domain, offset);
1642 irq_dispose_mapping(irq);
1643 }
1644
1645 irq_domain_remove(gc->irq.domain);
1646 }
1647
1648 if (irqchip) {
1649 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1650 irqchip->irq_request_resources = NULL;
1651 irqchip->irq_release_resources = NULL;
1652 }
1653 if (irqchip->irq_enable == gpiochip_irq_enable) {
1654 irqchip->irq_enable = gc->irq.irq_enable;
1655 irqchip->irq_disable = gc->irq.irq_disable;
1656 }
1657 }
1658 gc->irq.irq_enable = NULL;
1659 gc->irq.irq_disable = NULL;
1660 gc->irq.chip = NULL;
1661
1662 gpiochip_irqchip_free_valid_mask(gc);
1663 }
1664
1665 /**
1666 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1667 * @gc: the gpiochip to add the irqchip to
1668 * @domain: the irqdomain to add to the gpiochip
1669 *
1670 * This function adds an IRQ domain to the gpiochip.
1671 */
gpiochip_irqchip_add_domain(struct gpio_chip * gc,struct irq_domain * domain)1672 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1673 struct irq_domain *domain)
1674 {
1675 if (!domain)
1676 return -EINVAL;
1677
1678 gc->to_irq = gpiochip_to_irq;
1679 gc->irq.domain = domain;
1680
1681 return 0;
1682 }
1683 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1684
1685 #else /* CONFIG_GPIOLIB_IRQCHIP */
1686
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)1687 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1688 struct lock_class_key *lock_key,
1689 struct lock_class_key *request_key)
1690 {
1691 return 0;
1692 }
gpiochip_irqchip_remove(struct gpio_chip * gc)1693 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1694
gpiochip_irqchip_init_hw(struct gpio_chip * gc)1695 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1696 {
1697 return 0;
1698 }
1699
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)1700 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1701 {
1702 return 0;
1703 }
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)1704 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1705 { }
1706
1707 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1708
1709 /**
1710 * gpiochip_generic_request() - request the gpio function for a pin
1711 * @gc: the gpiochip owning the GPIO
1712 * @offset: the offset of the GPIO to request for GPIO function
1713 */
gpiochip_generic_request(struct gpio_chip * gc,unsigned int offset)1714 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
1715 {
1716 #ifdef CONFIG_PINCTRL
1717 if (list_empty(&gc->gpiodev->pin_ranges))
1718 return 0;
1719 #endif
1720
1721 return pinctrl_gpio_request(gc->gpiodev->base + offset);
1722 }
1723 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1724
1725 /**
1726 * gpiochip_generic_free() - free the gpio function from a pin
1727 * @gc: the gpiochip to request the gpio function for
1728 * @offset: the offset of the GPIO to free from GPIO function
1729 */
gpiochip_generic_free(struct gpio_chip * gc,unsigned int offset)1730 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
1731 {
1732 #ifdef CONFIG_PINCTRL
1733 if (list_empty(&gc->gpiodev->pin_ranges))
1734 return;
1735 #endif
1736
1737 pinctrl_gpio_free(gc->gpiodev->base + offset);
1738 }
1739 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1740
1741 /**
1742 * gpiochip_generic_config() - apply configuration for a pin
1743 * @gc: the gpiochip owning the GPIO
1744 * @offset: the offset of the GPIO to apply the configuration
1745 * @config: the configuration to be applied
1746 */
gpiochip_generic_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)1747 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
1748 unsigned long config)
1749 {
1750 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1751 }
1752 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1753
1754 #ifdef CONFIG_PINCTRL
1755
1756 /**
1757 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1758 * @gc: the gpiochip to add the range for
1759 * @pctldev: the pin controller to map to
1760 * @gpio_offset: the start offset in the current gpio_chip number space
1761 * @pin_group: name of the pin group inside the pin controller
1762 *
1763 * Calling this function directly from a DeviceTree-supported
1764 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1765 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1766 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1767 */
gpiochip_add_pingroup_range(struct gpio_chip * gc,struct pinctrl_dev * pctldev,unsigned int gpio_offset,const char * pin_group)1768 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1769 struct pinctrl_dev *pctldev,
1770 unsigned int gpio_offset, const char *pin_group)
1771 {
1772 struct gpio_pin_range *pin_range;
1773 struct gpio_device *gdev = gc->gpiodev;
1774 int ret;
1775
1776 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1777 if (!pin_range) {
1778 chip_err(gc, "failed to allocate pin ranges\n");
1779 return -ENOMEM;
1780 }
1781
1782 /* Use local offset as range ID */
1783 pin_range->range.id = gpio_offset;
1784 pin_range->range.gc = gc;
1785 pin_range->range.name = gc->label;
1786 pin_range->range.base = gdev->base + gpio_offset;
1787 pin_range->pctldev = pctldev;
1788
1789 ret = pinctrl_get_group_pins(pctldev, pin_group,
1790 &pin_range->range.pins,
1791 &pin_range->range.npins);
1792 if (ret < 0) {
1793 kfree(pin_range);
1794 return ret;
1795 }
1796
1797 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1798
1799 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1800 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1801 pinctrl_dev_get_devname(pctldev), pin_group);
1802
1803 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1804
1805 return 0;
1806 }
1807 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1808
1809 /**
1810 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1811 * @gc: the gpiochip to add the range for
1812 * @pinctl_name: the dev_name() of the pin controller to map to
1813 * @gpio_offset: the start offset in the current gpio_chip number space
1814 * @pin_offset: the start offset in the pin controller number space
1815 * @npins: the number of pins from the offset of each pin space (GPIO and
1816 * pin controller) to accumulate in this range
1817 *
1818 * Returns:
1819 * 0 on success, or a negative error-code on failure.
1820 *
1821 * Calling this function directly from a DeviceTree-supported
1822 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1823 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1824 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1825 */
gpiochip_add_pin_range(struct gpio_chip * gc,const char * pinctl_name,unsigned int gpio_offset,unsigned int pin_offset,unsigned int npins)1826 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1827 unsigned int gpio_offset, unsigned int pin_offset,
1828 unsigned int npins)
1829 {
1830 struct gpio_pin_range *pin_range;
1831 struct gpio_device *gdev = gc->gpiodev;
1832 int ret;
1833
1834 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1835 if (!pin_range) {
1836 chip_err(gc, "failed to allocate pin ranges\n");
1837 return -ENOMEM;
1838 }
1839
1840 /* Use local offset as range ID */
1841 pin_range->range.id = gpio_offset;
1842 pin_range->range.gc = gc;
1843 pin_range->range.name = gc->label;
1844 pin_range->range.base = gdev->base + gpio_offset;
1845 pin_range->range.pin_base = pin_offset;
1846 pin_range->range.npins = npins;
1847 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1848 &pin_range->range);
1849 if (IS_ERR(pin_range->pctldev)) {
1850 ret = PTR_ERR(pin_range->pctldev);
1851 chip_err(gc, "could not create pin range\n");
1852 kfree(pin_range);
1853 return ret;
1854 }
1855 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1856 gpio_offset, gpio_offset + npins - 1,
1857 pinctl_name,
1858 pin_offset, pin_offset + npins - 1);
1859
1860 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1861
1862 return 0;
1863 }
1864 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1865
1866 /**
1867 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1868 * @gc: the chip to remove all the mappings for
1869 */
gpiochip_remove_pin_ranges(struct gpio_chip * gc)1870 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1871 {
1872 struct gpio_pin_range *pin_range, *tmp;
1873 struct gpio_device *gdev = gc->gpiodev;
1874
1875 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1876 list_del(&pin_range->node);
1877 pinctrl_remove_gpio_range(pin_range->pctldev,
1878 &pin_range->range);
1879 kfree(pin_range);
1880 }
1881 }
1882 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1883
1884 #endif /* CONFIG_PINCTRL */
1885
1886 /* These "optional" allocation calls help prevent drivers from stomping
1887 * on each other, and help provide better diagnostics in debugfs.
1888 * They're called even less than the "set direction" calls.
1889 */
gpiod_request_commit(struct gpio_desc * desc,const char * label)1890 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
1891 {
1892 struct gpio_chip *gc = desc->gdev->chip;
1893 int ret;
1894 unsigned long flags;
1895 unsigned offset;
1896
1897 if (label) {
1898 label = kstrdup_const(label, GFP_KERNEL);
1899 if (!label)
1900 return -ENOMEM;
1901 }
1902
1903 spin_lock_irqsave(&gpio_lock, flags);
1904
1905 /* NOTE: gpio_request() can be called in early boot,
1906 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1907 */
1908
1909 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1910 desc_set_label(desc, label ? : "?");
1911 } else {
1912 ret = -EBUSY;
1913 goto out_free_unlock;
1914 }
1915
1916 if (gc->request) {
1917 /* gc->request may sleep */
1918 spin_unlock_irqrestore(&gpio_lock, flags);
1919 offset = gpio_chip_hwgpio(desc);
1920 if (gpiochip_line_is_valid(gc, offset))
1921 ret = gc->request(gc, offset);
1922 else
1923 ret = -EINVAL;
1924 spin_lock_irqsave(&gpio_lock, flags);
1925
1926 if (ret) {
1927 desc_set_label(desc, NULL);
1928 clear_bit(FLAG_REQUESTED, &desc->flags);
1929 goto out_free_unlock;
1930 }
1931 }
1932 if (gc->get_direction) {
1933 /* gc->get_direction may sleep */
1934 spin_unlock_irqrestore(&gpio_lock, flags);
1935 gpiod_get_direction(desc);
1936 spin_lock_irqsave(&gpio_lock, flags);
1937 }
1938 spin_unlock_irqrestore(&gpio_lock, flags);
1939 return 0;
1940
1941 out_free_unlock:
1942 spin_unlock_irqrestore(&gpio_lock, flags);
1943 kfree_const(label);
1944 return ret;
1945 }
1946
1947 /*
1948 * This descriptor validation needs to be inserted verbatim into each
1949 * function taking a descriptor, so we need to use a preprocessor
1950 * macro to avoid endless duplication. If the desc is NULL it is an
1951 * optional GPIO and calls should just bail out.
1952 */
validate_desc(const struct gpio_desc * desc,const char * func)1953 static int validate_desc(const struct gpio_desc *desc, const char *func)
1954 {
1955 if (!desc)
1956 return 0;
1957 if (IS_ERR(desc)) {
1958 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
1959 return PTR_ERR(desc);
1960 }
1961 if (!desc->gdev) {
1962 pr_warn("%s: invalid GPIO (no device)\n", func);
1963 return -EINVAL;
1964 }
1965 if (!desc->gdev->chip) {
1966 dev_warn(&desc->gdev->dev,
1967 "%s: backing chip is gone\n", func);
1968 return 0;
1969 }
1970 return 1;
1971 }
1972
1973 #define VALIDATE_DESC(desc) do { \
1974 int __valid = validate_desc(desc, __func__); \
1975 if (__valid <= 0) \
1976 return __valid; \
1977 } while (0)
1978
1979 #define VALIDATE_DESC_VOID(desc) do { \
1980 int __valid = validate_desc(desc, __func__); \
1981 if (__valid <= 0) \
1982 return; \
1983 } while (0)
1984
gpiod_request(struct gpio_desc * desc,const char * label)1985 int gpiod_request(struct gpio_desc *desc, const char *label)
1986 {
1987 int ret = -EPROBE_DEFER;
1988 struct gpio_device *gdev;
1989
1990 VALIDATE_DESC(desc);
1991 gdev = desc->gdev;
1992
1993 if (try_module_get(gdev->owner)) {
1994 ret = gpiod_request_commit(desc, label);
1995 if (ret)
1996 module_put(gdev->owner);
1997 else
1998 get_device(&gdev->dev);
1999 }
2000
2001 if (ret)
2002 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2003
2004 return ret;
2005 }
2006
gpiod_free_commit(struct gpio_desc * desc)2007 static bool gpiod_free_commit(struct gpio_desc *desc)
2008 {
2009 bool ret = false;
2010 unsigned long flags;
2011 struct gpio_chip *gc;
2012
2013 might_sleep();
2014
2015 gpiod_unexport(desc);
2016
2017 spin_lock_irqsave(&gpio_lock, flags);
2018
2019 gc = desc->gdev->chip;
2020 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
2021 if (gc->free) {
2022 spin_unlock_irqrestore(&gpio_lock, flags);
2023 might_sleep_if(gc->can_sleep);
2024 gc->free(gc, gpio_chip_hwgpio(desc));
2025 spin_lock_irqsave(&gpio_lock, flags);
2026 }
2027 kfree_const(desc->label);
2028 desc_set_label(desc, NULL);
2029 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2030 clear_bit(FLAG_REQUESTED, &desc->flags);
2031 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2032 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2033 clear_bit(FLAG_PULL_UP, &desc->flags);
2034 clear_bit(FLAG_PULL_DOWN, &desc->flags);
2035 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
2036 clear_bit(FLAG_EDGE_RISING, &desc->flags);
2037 clear_bit(FLAG_EDGE_FALLING, &desc->flags);
2038 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2039 #ifdef CONFIG_OF_DYNAMIC
2040 desc->hog = NULL;
2041 #endif
2042 #ifdef CONFIG_GPIO_CDEV
2043 WRITE_ONCE(desc->debounce_period_us, 0);
2044 #endif
2045 ret = true;
2046 }
2047
2048 spin_unlock_irqrestore(&gpio_lock, flags);
2049 blocking_notifier_call_chain(&desc->gdev->notifier,
2050 GPIOLINE_CHANGED_RELEASED, desc);
2051
2052 return ret;
2053 }
2054
gpiod_free(struct gpio_desc * desc)2055 void gpiod_free(struct gpio_desc *desc)
2056 {
2057 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2058 module_put(desc->gdev->owner);
2059 put_device(&desc->gdev->dev);
2060 } else {
2061 WARN_ON(extra_checks);
2062 }
2063 }
2064
2065 /**
2066 * gpiochip_is_requested - return string iff signal was requested
2067 * @gc: controller managing the signal
2068 * @offset: of signal within controller's 0..(ngpio - 1) range
2069 *
2070 * Returns NULL if the GPIO is not currently requested, else a string.
2071 * The string returned is the label passed to gpio_request(); if none has been
2072 * passed it is a meaningless, non-NULL constant.
2073 *
2074 * This function is for use by GPIO controller drivers. The label can
2075 * help with diagnostics, and knowing that the signal is used as a GPIO
2076 * can help avoid accidentally multiplexing it to another controller.
2077 */
gpiochip_is_requested(struct gpio_chip * gc,unsigned int offset)2078 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
2079 {
2080 struct gpio_desc *desc;
2081
2082 desc = gpiochip_get_desc(gc, offset);
2083 if (IS_ERR(desc))
2084 return NULL;
2085
2086 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2087 return NULL;
2088 return desc->label;
2089 }
2090 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2091
2092 /**
2093 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2094 * @gc: GPIO chip
2095 * @hwnum: hardware number of the GPIO for which to request the descriptor
2096 * @label: label for the GPIO
2097 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2098 * specify things like line inversion semantics with the machine flags
2099 * such as GPIO_OUT_LOW
2100 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2101 * can be used to specify consumer semantics such as open drain
2102 *
2103 * Function allows GPIO chip drivers to request and use their own GPIO
2104 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2105 * function will not increase reference count of the GPIO chip module. This
2106 * allows the GPIO chip module to be unloaded as needed (we assume that the
2107 * GPIO chip driver handles freeing the GPIOs it has requested).
2108 *
2109 * Returns:
2110 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2111 * code on failure.
2112 */
gpiochip_request_own_desc(struct gpio_chip * gc,unsigned int hwnum,const char * label,enum gpio_lookup_flags lflags,enum gpiod_flags dflags)2113 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2114 unsigned int hwnum,
2115 const char *label,
2116 enum gpio_lookup_flags lflags,
2117 enum gpiod_flags dflags)
2118 {
2119 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2120 int ret;
2121
2122 if (IS_ERR(desc)) {
2123 chip_err(gc, "failed to get GPIO descriptor\n");
2124 return desc;
2125 }
2126
2127 ret = gpiod_request_commit(desc, label);
2128 if (ret < 0)
2129 return ERR_PTR(ret);
2130
2131 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2132 if (ret) {
2133 chip_err(gc, "setup of own GPIO %s failed\n", label);
2134 gpiod_free_commit(desc);
2135 return ERR_PTR(ret);
2136 }
2137
2138 return desc;
2139 }
2140 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2141
2142 /**
2143 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2144 * @desc: GPIO descriptor to free
2145 *
2146 * Function frees the given GPIO requested previously with
2147 * gpiochip_request_own_desc().
2148 */
gpiochip_free_own_desc(struct gpio_desc * desc)2149 void gpiochip_free_own_desc(struct gpio_desc *desc)
2150 {
2151 if (desc)
2152 gpiod_free_commit(desc);
2153 }
2154 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2155
2156 /*
2157 * Drivers MUST set GPIO direction before making get/set calls. In
2158 * some cases this is done in early boot, before IRQs are enabled.
2159 *
2160 * As a rule these aren't called more than once (except for drivers
2161 * using the open-drain emulation idiom) so these are natural places
2162 * to accumulate extra debugging checks. Note that we can't (yet)
2163 * rely on gpio_request() having been called beforehand.
2164 */
2165
gpio_do_set_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2166 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2167 unsigned long config)
2168 {
2169 if (!gc->set_config)
2170 return -ENOTSUPP;
2171
2172 return gc->set_config(gc, offset, config);
2173 }
2174
gpio_set_config_with_argument(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2175 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2176 enum pin_config_param mode,
2177 u32 argument)
2178 {
2179 struct gpio_chip *gc = desc->gdev->chip;
2180 unsigned long config;
2181
2182 config = pinconf_to_config_packed(mode, argument);
2183 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2184 }
2185
gpio_set_config_with_argument_optional(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2186 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2187 enum pin_config_param mode,
2188 u32 argument)
2189 {
2190 struct device *dev = &desc->gdev->dev;
2191 int gpio = gpio_chip_hwgpio(desc);
2192 int ret;
2193
2194 ret = gpio_set_config_with_argument(desc, mode, argument);
2195 if (ret != -ENOTSUPP)
2196 return ret;
2197
2198 switch (mode) {
2199 case PIN_CONFIG_PERSIST_STATE:
2200 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2201 break;
2202 default:
2203 break;
2204 }
2205
2206 return 0;
2207 }
2208
gpio_set_config(struct gpio_desc * desc,enum pin_config_param mode)2209 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2210 {
2211 return gpio_set_config_with_argument(desc, mode, 0);
2212 }
2213
gpio_set_bias(struct gpio_desc * desc)2214 static int gpio_set_bias(struct gpio_desc *desc)
2215 {
2216 enum pin_config_param bias;
2217 unsigned int arg;
2218
2219 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2220 bias = PIN_CONFIG_BIAS_DISABLE;
2221 else if (test_bit(FLAG_PULL_UP, &desc->flags))
2222 bias = PIN_CONFIG_BIAS_PULL_UP;
2223 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2224 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2225 else
2226 return 0;
2227
2228 switch (bias) {
2229 case PIN_CONFIG_BIAS_PULL_DOWN:
2230 case PIN_CONFIG_BIAS_PULL_UP:
2231 arg = 1;
2232 break;
2233
2234 default:
2235 arg = 0;
2236 break;
2237 }
2238
2239 return gpio_set_config_with_argument_optional(desc, bias, arg);
2240 }
2241
2242 /**
2243 * gpio_set_debounce_timeout() - Set debounce timeout
2244 * @desc: GPIO descriptor to set the debounce timeout
2245 * @debounce: Debounce timeout in microseconds
2246 *
2247 * The function calls the certain GPIO driver to set debounce timeout
2248 * in the hardware.
2249 *
2250 * Returns 0 on success, or negative error code otherwise.
2251 */
gpio_set_debounce_timeout(struct gpio_desc * desc,unsigned int debounce)2252 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2253 {
2254 return gpio_set_config_with_argument_optional(desc,
2255 PIN_CONFIG_INPUT_DEBOUNCE,
2256 debounce);
2257 }
2258
2259 /**
2260 * gpiod_direction_input - set the GPIO direction to input
2261 * @desc: GPIO to set to input
2262 *
2263 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2264 * be called safely on it.
2265 *
2266 * Return 0 in case of success, else an error code.
2267 */
gpiod_direction_input(struct gpio_desc * desc)2268 int gpiod_direction_input(struct gpio_desc *desc)
2269 {
2270 struct gpio_chip *gc;
2271 int ret = 0;
2272
2273 VALIDATE_DESC(desc);
2274 gc = desc->gdev->chip;
2275
2276 /*
2277 * It is legal to have no .get() and .direction_input() specified if
2278 * the chip is output-only, but you can't specify .direction_input()
2279 * and not support the .get() operation, that doesn't make sense.
2280 */
2281 if (!gc->get && gc->direction_input) {
2282 gpiod_warn(desc,
2283 "%s: missing get() but have direction_input()\n",
2284 __func__);
2285 return -EIO;
2286 }
2287
2288 /*
2289 * If we have a .direction_input() callback, things are simple,
2290 * just call it. Else we are some input-only chip so try to check the
2291 * direction (if .get_direction() is supported) else we silently
2292 * assume we are in input mode after this.
2293 */
2294 if (gc->direction_input) {
2295 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2296 } else if (gc->get_direction &&
2297 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2298 gpiod_warn(desc,
2299 "%s: missing direction_input() operation and line is output\n",
2300 __func__);
2301 return -EIO;
2302 }
2303 if (ret == 0) {
2304 clear_bit(FLAG_IS_OUT, &desc->flags);
2305 ret = gpio_set_bias(desc);
2306 }
2307
2308 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2309
2310 return ret;
2311 }
2312 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2313
gpiod_direction_output_raw_commit(struct gpio_desc * desc,int value)2314 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2315 {
2316 struct gpio_chip *gc = desc->gdev->chip;
2317 int val = !!value;
2318 int ret = 0;
2319
2320 /*
2321 * It's OK not to specify .direction_output() if the gpiochip is
2322 * output-only, but if there is then not even a .set() operation it
2323 * is pretty tricky to drive the output line.
2324 */
2325 if (!gc->set && !gc->direction_output) {
2326 gpiod_warn(desc,
2327 "%s: missing set() and direction_output() operations\n",
2328 __func__);
2329 return -EIO;
2330 }
2331
2332 if (gc->direction_output) {
2333 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2334 } else {
2335 /* Check that we are in output mode if we can */
2336 if (gc->get_direction &&
2337 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2338 gpiod_warn(desc,
2339 "%s: missing direction_output() operation\n",
2340 __func__);
2341 return -EIO;
2342 }
2343 /*
2344 * If we can't actively set the direction, we are some
2345 * output-only chip, so just drive the output as desired.
2346 */
2347 gc->set(gc, gpio_chip_hwgpio(desc), val);
2348 }
2349
2350 if (!ret)
2351 set_bit(FLAG_IS_OUT, &desc->flags);
2352 trace_gpio_value(desc_to_gpio(desc), 0, val);
2353 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2354 return ret;
2355 }
2356
2357 /**
2358 * gpiod_direction_output_raw - set the GPIO direction to output
2359 * @desc: GPIO to set to output
2360 * @value: initial output value of the GPIO
2361 *
2362 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2363 * be called safely on it. The initial value of the output must be specified
2364 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2365 *
2366 * Return 0 in case of success, else an error code.
2367 */
gpiod_direction_output_raw(struct gpio_desc * desc,int value)2368 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2369 {
2370 VALIDATE_DESC(desc);
2371 return gpiod_direction_output_raw_commit(desc, value);
2372 }
2373 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2374
2375 /**
2376 * gpiod_direction_output - set the GPIO direction to output
2377 * @desc: GPIO to set to output
2378 * @value: initial output value of the GPIO
2379 *
2380 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2381 * be called safely on it. The initial value of the output must be specified
2382 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2383 * account.
2384 *
2385 * Return 0 in case of success, else an error code.
2386 */
gpiod_direction_output(struct gpio_desc * desc,int value)2387 int gpiod_direction_output(struct gpio_desc *desc, int value)
2388 {
2389 int ret;
2390
2391 VALIDATE_DESC(desc);
2392 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2393 value = !value;
2394 else
2395 value = !!value;
2396
2397 /* GPIOs used for enabled IRQs shall not be set as output */
2398 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2399 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2400 gpiod_err(desc,
2401 "%s: tried to set a GPIO tied to an IRQ as output\n",
2402 __func__);
2403 return -EIO;
2404 }
2405
2406 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2407 /* First see if we can enable open drain in hardware */
2408 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2409 if (!ret)
2410 goto set_output_value;
2411 /* Emulate open drain by not actively driving the line high */
2412 if (value) {
2413 ret = gpiod_direction_input(desc);
2414 goto set_output_flag;
2415 }
2416 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2417 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2418 if (!ret)
2419 goto set_output_value;
2420 /* Emulate open source by not actively driving the line low */
2421 if (!value) {
2422 ret = gpiod_direction_input(desc);
2423 goto set_output_flag;
2424 }
2425 } else {
2426 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2427 }
2428
2429 set_output_value:
2430 ret = gpio_set_bias(desc);
2431 if (ret)
2432 return ret;
2433 return gpiod_direction_output_raw_commit(desc, value);
2434
2435 set_output_flag:
2436 /*
2437 * When emulating open-source or open-drain functionalities by not
2438 * actively driving the line (setting mode to input) we still need to
2439 * set the IS_OUT flag or otherwise we won't be able to set the line
2440 * value anymore.
2441 */
2442 if (ret == 0)
2443 set_bit(FLAG_IS_OUT, &desc->flags);
2444 return ret;
2445 }
2446 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2447
2448 /**
2449 * gpiod_set_config - sets @config for a GPIO
2450 * @desc: descriptor of the GPIO for which to set the configuration
2451 * @config: Same packed config format as generic pinconf
2452 *
2453 * Returns:
2454 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2455 * configuration.
2456 */
gpiod_set_config(struct gpio_desc * desc,unsigned long config)2457 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2458 {
2459 struct gpio_chip *gc;
2460
2461 VALIDATE_DESC(desc);
2462 gc = desc->gdev->chip;
2463
2464 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2465 }
2466 EXPORT_SYMBOL_GPL(gpiod_set_config);
2467
2468 /**
2469 * gpiod_set_debounce - sets @debounce time for a GPIO
2470 * @desc: descriptor of the GPIO for which to set debounce time
2471 * @debounce: debounce time in microseconds
2472 *
2473 * Returns:
2474 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2475 * debounce time.
2476 */
gpiod_set_debounce(struct gpio_desc * desc,unsigned int debounce)2477 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2478 {
2479 unsigned long config;
2480
2481 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2482 return gpiod_set_config(desc, config);
2483 }
2484 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2485
2486 /**
2487 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2488 * @desc: descriptor of the GPIO for which to configure persistence
2489 * @transitory: True to lose state on suspend or reset, false for persistence
2490 *
2491 * Returns:
2492 * 0 on success, otherwise a negative error code.
2493 */
gpiod_set_transitory(struct gpio_desc * desc,bool transitory)2494 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2495 {
2496 VALIDATE_DESC(desc);
2497 /*
2498 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2499 * persistence state.
2500 */
2501 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2502
2503 /* If the driver supports it, set the persistence state now */
2504 return gpio_set_config_with_argument_optional(desc,
2505 PIN_CONFIG_PERSIST_STATE,
2506 !transitory);
2507 }
2508 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2509
2510 /**
2511 * gpiod_is_active_low - test whether a GPIO is active-low or not
2512 * @desc: the gpio descriptor to test
2513 *
2514 * Returns 1 if the GPIO is active-low, 0 otherwise.
2515 */
gpiod_is_active_low(const struct gpio_desc * desc)2516 int gpiod_is_active_low(const struct gpio_desc *desc)
2517 {
2518 VALIDATE_DESC(desc);
2519 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2520 }
2521 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2522
2523 /**
2524 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2525 * @desc: the gpio descriptor to change
2526 */
gpiod_toggle_active_low(struct gpio_desc * desc)2527 void gpiod_toggle_active_low(struct gpio_desc *desc)
2528 {
2529 VALIDATE_DESC_VOID(desc);
2530 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2531 }
2532 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2533
2534 /* I/O calls are only valid after configuration completed; the relevant
2535 * "is this a valid GPIO" error checks should already have been done.
2536 *
2537 * "Get" operations are often inlinable as reading a pin value register,
2538 * and masking the relevant bit in that register.
2539 *
2540 * When "set" operations are inlinable, they involve writing that mask to
2541 * one register to set a low value, or a different register to set it high.
2542 * Otherwise locking is needed, so there may be little value to inlining.
2543 *
2544 *------------------------------------------------------------------------
2545 *
2546 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2547 * have requested the GPIO. That can include implicit requesting by
2548 * a direction setting call. Marking a gpio as requested locks its chip
2549 * in memory, guaranteeing that these table lookups need no more locking
2550 * and that gpiochip_remove() will fail.
2551 *
2552 * REVISIT when debugging, consider adding some instrumentation to ensure
2553 * that the GPIO was actually requested.
2554 */
2555
gpiod_get_raw_value_commit(const struct gpio_desc * desc)2556 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2557 {
2558 struct gpio_chip *gc;
2559 int offset;
2560 int value;
2561
2562 gc = desc->gdev->chip;
2563 offset = gpio_chip_hwgpio(desc);
2564 value = gc->get ? gc->get(gc, offset) : -EIO;
2565 value = value < 0 ? value : !!value;
2566 trace_gpio_value(desc_to_gpio(desc), 1, value);
2567 return value;
2568 }
2569
gpio_chip_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)2570 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2571 unsigned long *mask, unsigned long *bits)
2572 {
2573 if (gc->get_multiple)
2574 return gc->get_multiple(gc, mask, bits);
2575 if (gc->get) {
2576 int i, value;
2577
2578 for_each_set_bit(i, mask, gc->ngpio) {
2579 value = gc->get(gc, i);
2580 if (value < 0)
2581 return value;
2582 __assign_bit(i, bits, value);
2583 }
2584 return 0;
2585 }
2586 return -EIO;
2587 }
2588
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)2589 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2590 unsigned int array_size,
2591 struct gpio_desc **desc_array,
2592 struct gpio_array *array_info,
2593 unsigned long *value_bitmap)
2594 {
2595 int ret, i = 0;
2596
2597 /*
2598 * Validate array_info against desc_array and its size.
2599 * It should immediately follow desc_array if both
2600 * have been obtained from the same gpiod_get_array() call.
2601 */
2602 if (array_info && array_info->desc == desc_array &&
2603 array_size <= array_info->size &&
2604 (void *)array_info == desc_array + array_info->size) {
2605 if (!can_sleep)
2606 WARN_ON(array_info->chip->can_sleep);
2607
2608 ret = gpio_chip_get_multiple(array_info->chip,
2609 array_info->get_mask,
2610 value_bitmap);
2611 if (ret)
2612 return ret;
2613
2614 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2615 bitmap_xor(value_bitmap, value_bitmap,
2616 array_info->invert_mask, array_size);
2617
2618 i = find_first_zero_bit(array_info->get_mask, array_size);
2619 if (i == array_size)
2620 return 0;
2621 } else {
2622 array_info = NULL;
2623 }
2624
2625 while (i < array_size) {
2626 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2627 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2628 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2629 unsigned long *mask, *bits;
2630 int first, j;
2631
2632 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2633 mask = fastpath_mask;
2634 bits = fastpath_bits;
2635 } else {
2636 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2637
2638 mask = bitmap_alloc(gc->ngpio, flags);
2639 if (!mask)
2640 return -ENOMEM;
2641
2642 bits = bitmap_alloc(gc->ngpio, flags);
2643 if (!bits) {
2644 bitmap_free(mask);
2645 return -ENOMEM;
2646 }
2647 }
2648
2649 bitmap_zero(mask, gc->ngpio);
2650
2651 if (!can_sleep)
2652 WARN_ON(gc->can_sleep);
2653
2654 /* collect all inputs belonging to the same chip */
2655 first = i;
2656 do {
2657 const struct gpio_desc *desc = desc_array[i];
2658 int hwgpio = gpio_chip_hwgpio(desc);
2659
2660 __set_bit(hwgpio, mask);
2661 i++;
2662
2663 if (array_info)
2664 i = find_next_zero_bit(array_info->get_mask,
2665 array_size, i);
2666 } while ((i < array_size) &&
2667 (desc_array[i]->gdev->chip == gc));
2668
2669 ret = gpio_chip_get_multiple(gc, mask, bits);
2670 if (ret) {
2671 if (mask != fastpath_mask)
2672 bitmap_free(mask);
2673 if (bits != fastpath_bits)
2674 bitmap_free(bits);
2675 return ret;
2676 }
2677
2678 for (j = first; j < i; ) {
2679 const struct gpio_desc *desc = desc_array[j];
2680 int hwgpio = gpio_chip_hwgpio(desc);
2681 int value = test_bit(hwgpio, bits);
2682
2683 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2684 value = !value;
2685 __assign_bit(j, value_bitmap, value);
2686 trace_gpio_value(desc_to_gpio(desc), 1, value);
2687 j++;
2688
2689 if (array_info)
2690 j = find_next_zero_bit(array_info->get_mask, i,
2691 j);
2692 }
2693
2694 if (mask != fastpath_mask)
2695 bitmap_free(mask);
2696 if (bits != fastpath_bits)
2697 bitmap_free(bits);
2698 }
2699 return 0;
2700 }
2701
2702 /**
2703 * gpiod_get_raw_value() - return a gpio's raw value
2704 * @desc: gpio whose value will be returned
2705 *
2706 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2707 * its ACTIVE_LOW status, or negative errno on failure.
2708 *
2709 * This function can be called from contexts where we cannot sleep, and will
2710 * complain if the GPIO chip functions potentially sleep.
2711 */
gpiod_get_raw_value(const struct gpio_desc * desc)2712 int gpiod_get_raw_value(const struct gpio_desc *desc)
2713 {
2714 VALIDATE_DESC(desc);
2715 /* Should be using gpiod_get_raw_value_cansleep() */
2716 WARN_ON(desc->gdev->chip->can_sleep);
2717 return gpiod_get_raw_value_commit(desc);
2718 }
2719 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2720
2721 /**
2722 * gpiod_get_value() - return a gpio's value
2723 * @desc: gpio whose value will be returned
2724 *
2725 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2726 * account, or negative errno on failure.
2727 *
2728 * This function can be called from contexts where we cannot sleep, and will
2729 * complain if the GPIO chip functions potentially sleep.
2730 */
gpiod_get_value(const struct gpio_desc * desc)2731 int gpiod_get_value(const struct gpio_desc *desc)
2732 {
2733 int value;
2734
2735 VALIDATE_DESC(desc);
2736 /* Should be using gpiod_get_value_cansleep() */
2737 WARN_ON(desc->gdev->chip->can_sleep);
2738
2739 value = gpiod_get_raw_value_commit(desc);
2740 if (value < 0)
2741 return value;
2742
2743 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2744 value = !value;
2745
2746 return value;
2747 }
2748 EXPORT_SYMBOL_GPL(gpiod_get_value);
2749
2750 /**
2751 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2752 * @array_size: number of elements in the descriptor array / value bitmap
2753 * @desc_array: array of GPIO descriptors whose values will be read
2754 * @array_info: information on applicability of fast bitmap processing path
2755 * @value_bitmap: bitmap to store the read values
2756 *
2757 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2758 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2759 * else an error code.
2760 *
2761 * This function can be called from contexts where we cannot sleep,
2762 * and it will complain if the GPIO chip functions potentially sleep.
2763 */
gpiod_get_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2764 int gpiod_get_raw_array_value(unsigned int array_size,
2765 struct gpio_desc **desc_array,
2766 struct gpio_array *array_info,
2767 unsigned long *value_bitmap)
2768 {
2769 if (!desc_array)
2770 return -EINVAL;
2771 return gpiod_get_array_value_complex(true, false, array_size,
2772 desc_array, array_info,
2773 value_bitmap);
2774 }
2775 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2776
2777 /**
2778 * gpiod_get_array_value() - read values from an array of GPIOs
2779 * @array_size: number of elements in the descriptor array / value bitmap
2780 * @desc_array: array of GPIO descriptors whose values will be read
2781 * @array_info: information on applicability of fast bitmap processing path
2782 * @value_bitmap: bitmap to store the read values
2783 *
2784 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2785 * into account. Return 0 in case of success, else an error code.
2786 *
2787 * This function can be called from contexts where we cannot sleep,
2788 * and it will complain if the GPIO chip functions potentially sleep.
2789 */
gpiod_get_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)2790 int gpiod_get_array_value(unsigned int array_size,
2791 struct gpio_desc **desc_array,
2792 struct gpio_array *array_info,
2793 unsigned long *value_bitmap)
2794 {
2795 if (!desc_array)
2796 return -EINVAL;
2797 return gpiod_get_array_value_complex(false, false, array_size,
2798 desc_array, array_info,
2799 value_bitmap);
2800 }
2801 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2802
2803 /*
2804 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2805 * @desc: gpio descriptor whose state need to be set.
2806 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2807 */
gpio_set_open_drain_value_commit(struct gpio_desc * desc,bool value)2808 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2809 {
2810 int ret = 0;
2811 struct gpio_chip *gc = desc->gdev->chip;
2812 int offset = gpio_chip_hwgpio(desc);
2813
2814 if (value) {
2815 ret = gc->direction_input(gc, offset);
2816 } else {
2817 ret = gc->direction_output(gc, offset, 0);
2818 if (!ret)
2819 set_bit(FLAG_IS_OUT, &desc->flags);
2820 }
2821 trace_gpio_direction(desc_to_gpio(desc), value, ret);
2822 if (ret < 0)
2823 gpiod_err(desc,
2824 "%s: Error in set_value for open drain err %d\n",
2825 __func__, ret);
2826 }
2827
2828 /*
2829 * _gpio_set_open_source_value() - Set the open source gpio's value.
2830 * @desc: gpio descriptor whose state need to be set.
2831 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2832 */
gpio_set_open_source_value_commit(struct gpio_desc * desc,bool value)2833 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2834 {
2835 int ret = 0;
2836 struct gpio_chip *gc = desc->gdev->chip;
2837 int offset = gpio_chip_hwgpio(desc);
2838
2839 if (value) {
2840 ret = gc->direction_output(gc, offset, 1);
2841 if (!ret)
2842 set_bit(FLAG_IS_OUT, &desc->flags);
2843 } else {
2844 ret = gc->direction_input(gc, offset);
2845 }
2846 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2847 if (ret < 0)
2848 gpiod_err(desc,
2849 "%s: Error in set_value for open source err %d\n",
2850 __func__, ret);
2851 }
2852
gpiod_set_raw_value_commit(struct gpio_desc * desc,bool value)2853 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2854 {
2855 struct gpio_chip *gc;
2856
2857 gc = desc->gdev->chip;
2858 trace_gpio_value(desc_to_gpio(desc), 0, value);
2859 gc->set(gc, gpio_chip_hwgpio(desc), value);
2860 }
2861
2862 /*
2863 * set multiple outputs on the same chip;
2864 * use the chip's set_multiple function if available;
2865 * otherwise set the outputs sequentially;
2866 * @chip: the GPIO chip we operate on
2867 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2868 * defines which outputs are to be changed
2869 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2870 * defines the values the outputs specified by mask are to be set to
2871 */
gpio_chip_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)2872 static void gpio_chip_set_multiple(struct gpio_chip *gc,
2873 unsigned long *mask, unsigned long *bits)
2874 {
2875 if (gc->set_multiple) {
2876 gc->set_multiple(gc, mask, bits);
2877 } else {
2878 unsigned int i;
2879
2880 /* set outputs if the corresponding mask bit is set */
2881 for_each_set_bit(i, mask, gc->ngpio)
2882 gc->set(gc, i, test_bit(i, bits));
2883 }
2884 }
2885
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)2886 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2887 unsigned int array_size,
2888 struct gpio_desc **desc_array,
2889 struct gpio_array *array_info,
2890 unsigned long *value_bitmap)
2891 {
2892 int i = 0;
2893
2894 /*
2895 * Validate array_info against desc_array and its size.
2896 * It should immediately follow desc_array if both
2897 * have been obtained from the same gpiod_get_array() call.
2898 */
2899 if (array_info && array_info->desc == desc_array &&
2900 array_size <= array_info->size &&
2901 (void *)array_info == desc_array + array_info->size) {
2902 if (!can_sleep)
2903 WARN_ON(array_info->chip->can_sleep);
2904
2905 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2906 bitmap_xor(value_bitmap, value_bitmap,
2907 array_info->invert_mask, array_size);
2908
2909 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2910 value_bitmap);
2911
2912 i = find_first_zero_bit(array_info->set_mask, array_size);
2913 if (i == array_size)
2914 return 0;
2915 } else {
2916 array_info = NULL;
2917 }
2918
2919 while (i < array_size) {
2920 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2921 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2922 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2923 unsigned long *mask, *bits;
2924 int count = 0;
2925
2926 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2927 mask = fastpath_mask;
2928 bits = fastpath_bits;
2929 } else {
2930 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2931
2932 mask = bitmap_alloc(gc->ngpio, flags);
2933 if (!mask)
2934 return -ENOMEM;
2935
2936 bits = bitmap_alloc(gc->ngpio, flags);
2937 if (!bits) {
2938 bitmap_free(mask);
2939 return -ENOMEM;
2940 }
2941 }
2942
2943 bitmap_zero(mask, gc->ngpio);
2944
2945 if (!can_sleep)
2946 WARN_ON(gc->can_sleep);
2947
2948 do {
2949 struct gpio_desc *desc = desc_array[i];
2950 int hwgpio = gpio_chip_hwgpio(desc);
2951 int value = test_bit(i, value_bitmap);
2952
2953 /*
2954 * Pins applicable for fast input but not for
2955 * fast output processing may have been already
2956 * inverted inside the fast path, skip them.
2957 */
2958 if (!raw && !(array_info &&
2959 test_bit(i, array_info->invert_mask)) &&
2960 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2961 value = !value;
2962 trace_gpio_value(desc_to_gpio(desc), 0, value);
2963 /*
2964 * collect all normal outputs belonging to the same chip
2965 * open drain and open source outputs are set individually
2966 */
2967 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2968 gpio_set_open_drain_value_commit(desc, value);
2969 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2970 gpio_set_open_source_value_commit(desc, value);
2971 } else {
2972 __set_bit(hwgpio, mask);
2973 __assign_bit(hwgpio, bits, value);
2974 count++;
2975 }
2976 i++;
2977
2978 if (array_info)
2979 i = find_next_zero_bit(array_info->set_mask,
2980 array_size, i);
2981 } while ((i < array_size) &&
2982 (desc_array[i]->gdev->chip == gc));
2983 /* push collected bits to outputs */
2984 if (count != 0)
2985 gpio_chip_set_multiple(gc, mask, bits);
2986
2987 if (mask != fastpath_mask)
2988 bitmap_free(mask);
2989 if (bits != fastpath_bits)
2990 bitmap_free(bits);
2991 }
2992 return 0;
2993 }
2994
2995 /**
2996 * gpiod_set_raw_value() - assign a gpio's raw value
2997 * @desc: gpio whose value will be assigned
2998 * @value: value to assign
2999 *
3000 * Set the raw value of the GPIO, i.e. the value of its physical line without
3001 * regard for its ACTIVE_LOW status.
3002 *
3003 * This function can be called from contexts where we cannot sleep, and will
3004 * complain if the GPIO chip functions potentially sleep.
3005 */
gpiod_set_raw_value(struct gpio_desc * desc,int value)3006 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3007 {
3008 VALIDATE_DESC_VOID(desc);
3009 /* Should be using gpiod_set_raw_value_cansleep() */
3010 WARN_ON(desc->gdev->chip->can_sleep);
3011 gpiod_set_raw_value_commit(desc, value);
3012 }
3013 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3014
3015 /**
3016 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3017 * @desc: the descriptor to set the value on
3018 * @value: value to set
3019 *
3020 * This sets the value of a GPIO line backing a descriptor, applying
3021 * different semantic quirks like active low and open drain/source
3022 * handling.
3023 */
gpiod_set_value_nocheck(struct gpio_desc * desc,int value)3024 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3025 {
3026 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3027 value = !value;
3028 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3029 gpio_set_open_drain_value_commit(desc, value);
3030 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3031 gpio_set_open_source_value_commit(desc, value);
3032 else
3033 gpiod_set_raw_value_commit(desc, value);
3034 }
3035
3036 /**
3037 * gpiod_set_value() - assign a gpio's value
3038 * @desc: gpio whose value will be assigned
3039 * @value: value to assign
3040 *
3041 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3042 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3043 *
3044 * This function can be called from contexts where we cannot sleep, and will
3045 * complain if the GPIO chip functions potentially sleep.
3046 */
gpiod_set_value(struct gpio_desc * desc,int value)3047 void gpiod_set_value(struct gpio_desc *desc, int value)
3048 {
3049 VALIDATE_DESC_VOID(desc);
3050 /* Should be using gpiod_set_value_cansleep() */
3051 WARN_ON(desc->gdev->chip->can_sleep);
3052 gpiod_set_value_nocheck(desc, value);
3053 }
3054 EXPORT_SYMBOL_GPL(gpiod_set_value);
3055
3056 /**
3057 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3058 * @array_size: number of elements in the descriptor array / value bitmap
3059 * @desc_array: array of GPIO descriptors whose values will be assigned
3060 * @array_info: information on applicability of fast bitmap processing path
3061 * @value_bitmap: bitmap of values to assign
3062 *
3063 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3064 * without regard for their ACTIVE_LOW status.
3065 *
3066 * This function can be called from contexts where we cannot sleep, and will
3067 * complain if the GPIO chip functions potentially sleep.
3068 */
gpiod_set_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3069 int gpiod_set_raw_array_value(unsigned int array_size,
3070 struct gpio_desc **desc_array,
3071 struct gpio_array *array_info,
3072 unsigned long *value_bitmap)
3073 {
3074 if (!desc_array)
3075 return -EINVAL;
3076 return gpiod_set_array_value_complex(true, false, array_size,
3077 desc_array, array_info, value_bitmap);
3078 }
3079 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3080
3081 /**
3082 * gpiod_set_array_value() - assign values to an array of GPIOs
3083 * @array_size: number of elements in the descriptor array / value bitmap
3084 * @desc_array: array of GPIO descriptors whose values will be assigned
3085 * @array_info: information on applicability of fast bitmap processing path
3086 * @value_bitmap: bitmap of values to assign
3087 *
3088 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3089 * into account.
3090 *
3091 * This function can be called from contexts where we cannot sleep, and will
3092 * complain if the GPIO chip functions potentially sleep.
3093 */
gpiod_set_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3094 int gpiod_set_array_value(unsigned int array_size,
3095 struct gpio_desc **desc_array,
3096 struct gpio_array *array_info,
3097 unsigned long *value_bitmap)
3098 {
3099 if (!desc_array)
3100 return -EINVAL;
3101 return gpiod_set_array_value_complex(false, false, array_size,
3102 desc_array, array_info,
3103 value_bitmap);
3104 }
3105 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3106
3107 /**
3108 * gpiod_cansleep() - report whether gpio value access may sleep
3109 * @desc: gpio to check
3110 *
3111 */
gpiod_cansleep(const struct gpio_desc * desc)3112 int gpiod_cansleep(const struct gpio_desc *desc)
3113 {
3114 VALIDATE_DESC(desc);
3115 return desc->gdev->chip->can_sleep;
3116 }
3117 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3118
3119 /**
3120 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3121 * @desc: gpio to set the consumer name on
3122 * @name: the new consumer name
3123 */
gpiod_set_consumer_name(struct gpio_desc * desc,const char * name)3124 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3125 {
3126 VALIDATE_DESC(desc);
3127 if (name) {
3128 name = kstrdup_const(name, GFP_KERNEL);
3129 if (!name)
3130 return -ENOMEM;
3131 }
3132
3133 kfree_const(desc->label);
3134 desc_set_label(desc, name);
3135
3136 return 0;
3137 }
3138 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3139
3140 /**
3141 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3142 * @desc: gpio whose IRQ will be returned (already requested)
3143 *
3144 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3145 * error.
3146 */
gpiod_to_irq(const struct gpio_desc * desc)3147 int gpiod_to_irq(const struct gpio_desc *desc)
3148 {
3149 struct gpio_chip *gc;
3150 int offset;
3151
3152 /*
3153 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3154 * requires this function to not return zero on an invalid descriptor
3155 * but rather a negative error number.
3156 */
3157 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3158 return -EINVAL;
3159
3160 gc = desc->gdev->chip;
3161 offset = gpio_chip_hwgpio(desc);
3162 if (gc->to_irq) {
3163 int retirq = gc->to_irq(gc, offset);
3164
3165 /* Zero means NO_IRQ */
3166 if (!retirq)
3167 return -ENXIO;
3168
3169 return retirq;
3170 }
3171 #ifdef CONFIG_GPIOLIB_IRQCHIP
3172 if (gc->irq.chip) {
3173 /*
3174 * Avoid race condition with other code, which tries to lookup
3175 * an IRQ before the irqchip has been properly registered,
3176 * i.e. while gpiochip is still being brought up.
3177 */
3178 return -EPROBE_DEFER;
3179 }
3180 #endif
3181 return -ENXIO;
3182 }
3183 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3184
3185 /**
3186 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3187 * @gc: the chip the GPIO to lock belongs to
3188 * @offset: the offset of the GPIO to lock as IRQ
3189 *
3190 * This is used directly by GPIO drivers that want to lock down
3191 * a certain GPIO line to be used for IRQs.
3192 */
gpiochip_lock_as_irq(struct gpio_chip * gc,unsigned int offset)3193 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3194 {
3195 struct gpio_desc *desc;
3196
3197 desc = gpiochip_get_desc(gc, offset);
3198 if (IS_ERR(desc))
3199 return PTR_ERR(desc);
3200
3201 /*
3202 * If it's fast: flush the direction setting if something changed
3203 * behind our back
3204 */
3205 if (!gc->can_sleep && gc->get_direction) {
3206 int dir = gpiod_get_direction(desc);
3207
3208 if (dir < 0) {
3209 chip_err(gc, "%s: cannot get GPIO direction\n",
3210 __func__);
3211 return dir;
3212 }
3213 }
3214
3215 /* To be valid for IRQ the line needs to be input or open drain */
3216 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3217 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3218 chip_err(gc,
3219 "%s: tried to flag a GPIO set as output for IRQ\n",
3220 __func__);
3221 return -EIO;
3222 }
3223
3224 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3225 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3226
3227 /*
3228 * If the consumer has not set up a label (such as when the
3229 * IRQ is referenced from .to_irq()) we set up a label here
3230 * so it is clear this is used as an interrupt.
3231 */
3232 if (!desc->label)
3233 desc_set_label(desc, "interrupt");
3234
3235 return 0;
3236 }
3237 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3238
3239 /**
3240 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3241 * @gc: the chip the GPIO to lock belongs to
3242 * @offset: the offset of the GPIO to lock as IRQ
3243 *
3244 * This is used directly by GPIO drivers that want to indicate
3245 * that a certain GPIO is no longer used exclusively for IRQ.
3246 */
gpiochip_unlock_as_irq(struct gpio_chip * gc,unsigned int offset)3247 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3248 {
3249 struct gpio_desc *desc;
3250
3251 desc = gpiochip_get_desc(gc, offset);
3252 if (IS_ERR(desc))
3253 return;
3254
3255 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3256 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3257
3258 /* If we only had this marking, erase it */
3259 if (desc->label && !strcmp(desc->label, "interrupt"))
3260 desc_set_label(desc, NULL);
3261 }
3262 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3263
gpiochip_disable_irq(struct gpio_chip * gc,unsigned int offset)3264 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3265 {
3266 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3267
3268 if (!IS_ERR(desc) &&
3269 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3270 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3271 }
3272 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3273
gpiochip_enable_irq(struct gpio_chip * gc,unsigned int offset)3274 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3275 {
3276 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3277
3278 if (!IS_ERR(desc) &&
3279 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3280 /*
3281 * We must not be output when using IRQ UNLESS we are
3282 * open drain.
3283 */
3284 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3285 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3286 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3287 }
3288 }
3289 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3290
gpiochip_line_is_irq(struct gpio_chip * gc,unsigned int offset)3291 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3292 {
3293 if (offset >= gc->ngpio)
3294 return false;
3295
3296 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3297 }
3298 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3299
gpiochip_reqres_irq(struct gpio_chip * gc,unsigned int offset)3300 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3301 {
3302 int ret;
3303
3304 if (!try_module_get(gc->gpiodev->owner))
3305 return -ENODEV;
3306
3307 ret = gpiochip_lock_as_irq(gc, offset);
3308 if (ret) {
3309 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3310 module_put(gc->gpiodev->owner);
3311 return ret;
3312 }
3313 return 0;
3314 }
3315 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3316
gpiochip_relres_irq(struct gpio_chip * gc,unsigned int offset)3317 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3318 {
3319 gpiochip_unlock_as_irq(gc, offset);
3320 module_put(gc->gpiodev->owner);
3321 }
3322 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3323
gpiochip_line_is_open_drain(struct gpio_chip * gc,unsigned int offset)3324 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3325 {
3326 if (offset >= gc->ngpio)
3327 return false;
3328
3329 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3330 }
3331 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3332
gpiochip_line_is_open_source(struct gpio_chip * gc,unsigned int offset)3333 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3334 {
3335 if (offset >= gc->ngpio)
3336 return false;
3337
3338 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3339 }
3340 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3341
gpiochip_line_is_persistent(struct gpio_chip * gc,unsigned int offset)3342 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3343 {
3344 if (offset >= gc->ngpio)
3345 return false;
3346
3347 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3348 }
3349 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3350
3351 /**
3352 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3353 * @desc: gpio whose value will be returned
3354 *
3355 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3356 * its ACTIVE_LOW status, or negative errno on failure.
3357 *
3358 * This function is to be called from contexts that can sleep.
3359 */
gpiod_get_raw_value_cansleep(const struct gpio_desc * desc)3360 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3361 {
3362 might_sleep_if(extra_checks);
3363 VALIDATE_DESC(desc);
3364 return gpiod_get_raw_value_commit(desc);
3365 }
3366 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3367
3368 /**
3369 * gpiod_get_value_cansleep() - return a gpio's value
3370 * @desc: gpio whose value will be returned
3371 *
3372 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3373 * account, or negative errno on failure.
3374 *
3375 * This function is to be called from contexts that can sleep.
3376 */
gpiod_get_value_cansleep(const struct gpio_desc * desc)3377 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3378 {
3379 int value;
3380
3381 might_sleep_if(extra_checks);
3382 VALIDATE_DESC(desc);
3383 value = gpiod_get_raw_value_commit(desc);
3384 if (value < 0)
3385 return value;
3386
3387 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3388 value = !value;
3389
3390 return value;
3391 }
3392 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3393
3394 /**
3395 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3396 * @array_size: number of elements in the descriptor array / value bitmap
3397 * @desc_array: array of GPIO descriptors whose values will be read
3398 * @array_info: information on applicability of fast bitmap processing path
3399 * @value_bitmap: bitmap to store the read values
3400 *
3401 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3402 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3403 * else an error code.
3404 *
3405 * This function is to be called from contexts that can sleep.
3406 */
gpiod_get_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3407 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3408 struct gpio_desc **desc_array,
3409 struct gpio_array *array_info,
3410 unsigned long *value_bitmap)
3411 {
3412 might_sleep_if(extra_checks);
3413 if (!desc_array)
3414 return -EINVAL;
3415 return gpiod_get_array_value_complex(true, true, array_size,
3416 desc_array, array_info,
3417 value_bitmap);
3418 }
3419 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3420
3421 /**
3422 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3423 * @array_size: number of elements in the descriptor array / value bitmap
3424 * @desc_array: array of GPIO descriptors whose values will be read
3425 * @array_info: information on applicability of fast bitmap processing path
3426 * @value_bitmap: bitmap to store the read values
3427 *
3428 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3429 * into account. Return 0 in case of success, else an error code.
3430 *
3431 * This function is to be called from contexts that can sleep.
3432 */
gpiod_get_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3433 int gpiod_get_array_value_cansleep(unsigned int array_size,
3434 struct gpio_desc **desc_array,
3435 struct gpio_array *array_info,
3436 unsigned long *value_bitmap)
3437 {
3438 might_sleep_if(extra_checks);
3439 if (!desc_array)
3440 return -EINVAL;
3441 return gpiod_get_array_value_complex(false, true, array_size,
3442 desc_array, array_info,
3443 value_bitmap);
3444 }
3445 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3446
3447 /**
3448 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3449 * @desc: gpio whose value will be assigned
3450 * @value: value to assign
3451 *
3452 * Set the raw value of the GPIO, i.e. the value of its physical line without
3453 * regard for its ACTIVE_LOW status.
3454 *
3455 * This function is to be called from contexts that can sleep.
3456 */
gpiod_set_raw_value_cansleep(struct gpio_desc * desc,int value)3457 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3458 {
3459 might_sleep_if(extra_checks);
3460 VALIDATE_DESC_VOID(desc);
3461 gpiod_set_raw_value_commit(desc, value);
3462 }
3463 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3464
3465 /**
3466 * gpiod_set_value_cansleep() - assign a gpio's value
3467 * @desc: gpio whose value will be assigned
3468 * @value: value to assign
3469 *
3470 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3471 * account
3472 *
3473 * This function is to be called from contexts that can sleep.
3474 */
gpiod_set_value_cansleep(struct gpio_desc * desc,int value)3475 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3476 {
3477 might_sleep_if(extra_checks);
3478 VALIDATE_DESC_VOID(desc);
3479 gpiod_set_value_nocheck(desc, value);
3480 }
3481 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3482
3483 /**
3484 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3485 * @array_size: number of elements in the descriptor array / value bitmap
3486 * @desc_array: array of GPIO descriptors whose values will be assigned
3487 * @array_info: information on applicability of fast bitmap processing path
3488 * @value_bitmap: bitmap of values to assign
3489 *
3490 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3491 * without regard for their ACTIVE_LOW status.
3492 *
3493 * This function is to be called from contexts that can sleep.
3494 */
gpiod_set_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3495 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3496 struct gpio_desc **desc_array,
3497 struct gpio_array *array_info,
3498 unsigned long *value_bitmap)
3499 {
3500 might_sleep_if(extra_checks);
3501 if (!desc_array)
3502 return -EINVAL;
3503 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3504 array_info, value_bitmap);
3505 }
3506 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3507
3508 /**
3509 * gpiod_add_lookup_tables() - register GPIO device consumers
3510 * @tables: list of tables of consumers to register
3511 * @n: number of tables in the list
3512 */
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)3513 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3514 {
3515 unsigned int i;
3516
3517 mutex_lock(&gpio_lookup_lock);
3518
3519 for (i = 0; i < n; i++)
3520 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3521
3522 mutex_unlock(&gpio_lookup_lock);
3523 }
3524
3525 /**
3526 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3527 * @array_size: number of elements in the descriptor array / value bitmap
3528 * @desc_array: array of GPIO descriptors whose values will be assigned
3529 * @array_info: information on applicability of fast bitmap processing path
3530 * @value_bitmap: bitmap of values to assign
3531 *
3532 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3533 * into account.
3534 *
3535 * This function is to be called from contexts that can sleep.
3536 */
gpiod_set_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3537 int gpiod_set_array_value_cansleep(unsigned int array_size,
3538 struct gpio_desc **desc_array,
3539 struct gpio_array *array_info,
3540 unsigned long *value_bitmap)
3541 {
3542 might_sleep_if(extra_checks);
3543 if (!desc_array)
3544 return -EINVAL;
3545 return gpiod_set_array_value_complex(false, true, array_size,
3546 desc_array, array_info,
3547 value_bitmap);
3548 }
3549 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3550
3551 /**
3552 * gpiod_add_lookup_table() - register GPIO device consumers
3553 * @table: table of consumers to register
3554 */
gpiod_add_lookup_table(struct gpiod_lookup_table * table)3555 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3556 {
3557 mutex_lock(&gpio_lookup_lock);
3558
3559 list_add_tail(&table->list, &gpio_lookup_list);
3560
3561 mutex_unlock(&gpio_lookup_lock);
3562 }
3563 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3564
3565 /**
3566 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3567 * @table: table of consumers to unregister
3568 */
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)3569 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3570 {
3571 /* Nothing to remove */
3572 if (!table)
3573 return;
3574
3575 mutex_lock(&gpio_lookup_lock);
3576
3577 list_del(&table->list);
3578
3579 mutex_unlock(&gpio_lookup_lock);
3580 }
3581 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3582
3583 /**
3584 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3585 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3586 */
gpiod_add_hogs(struct gpiod_hog * hogs)3587 void gpiod_add_hogs(struct gpiod_hog *hogs)
3588 {
3589 struct gpio_chip *gc;
3590 struct gpiod_hog *hog;
3591
3592 mutex_lock(&gpio_machine_hogs_mutex);
3593
3594 for (hog = &hogs[0]; hog->chip_label; hog++) {
3595 list_add_tail(&hog->list, &gpio_machine_hogs);
3596
3597 /*
3598 * The chip may have been registered earlier, so check if it
3599 * exists and, if so, try to hog the line now.
3600 */
3601 gc = find_chip_by_name(hog->chip_label);
3602 if (gc)
3603 gpiochip_machine_hog(gc, hog);
3604 }
3605
3606 mutex_unlock(&gpio_machine_hogs_mutex);
3607 }
3608 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3609
gpiod_find_lookup_table(struct device * dev)3610 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3611 {
3612 const char *dev_id = dev ? dev_name(dev) : NULL;
3613 struct gpiod_lookup_table *table;
3614
3615 mutex_lock(&gpio_lookup_lock);
3616
3617 list_for_each_entry(table, &gpio_lookup_list, list) {
3618 if (table->dev_id && dev_id) {
3619 /*
3620 * Valid strings on both ends, must be identical to have
3621 * a match
3622 */
3623 if (!strcmp(table->dev_id, dev_id))
3624 goto found;
3625 } else {
3626 /*
3627 * One of the pointers is NULL, so both must be to have
3628 * a match
3629 */
3630 if (dev_id == table->dev_id)
3631 goto found;
3632 }
3633 }
3634 table = NULL;
3635
3636 found:
3637 mutex_unlock(&gpio_lookup_lock);
3638 return table;
3639 }
3640
gpiod_find(struct device * dev,const char * con_id,unsigned int idx,unsigned long * flags)3641 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3642 unsigned int idx, unsigned long *flags)
3643 {
3644 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3645 struct gpiod_lookup_table *table;
3646 struct gpiod_lookup *p;
3647
3648 table = gpiod_find_lookup_table(dev);
3649 if (!table)
3650 return desc;
3651
3652 for (p = &table->table[0]; p->key; p++) {
3653 struct gpio_chip *gc;
3654
3655 /* idx must always match exactly */
3656 if (p->idx != idx)
3657 continue;
3658
3659 /* If the lookup entry has a con_id, require exact match */
3660 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3661 continue;
3662
3663 if (p->chip_hwnum == U16_MAX) {
3664 desc = gpio_name_to_desc(p->key);
3665 if (desc) {
3666 *flags = p->flags;
3667 return desc;
3668 }
3669
3670 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3671 p->key);
3672 return ERR_PTR(-EPROBE_DEFER);
3673 }
3674
3675 gc = find_chip_by_name(p->key);
3676
3677 if (!gc) {
3678 /*
3679 * As the lookup table indicates a chip with
3680 * p->key should exist, assume it may
3681 * still appear later and let the interested
3682 * consumer be probed again or let the Deferred
3683 * Probe infrastructure handle the error.
3684 */
3685 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3686 p->key);
3687 return ERR_PTR(-EPROBE_DEFER);
3688 }
3689
3690 if (gc->ngpio <= p->chip_hwnum) {
3691 dev_err(dev,
3692 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3693 idx, p->chip_hwnum, gc->ngpio - 1,
3694 gc->label);
3695 return ERR_PTR(-EINVAL);
3696 }
3697
3698 desc = gpiochip_get_desc(gc, p->chip_hwnum);
3699 *flags = p->flags;
3700
3701 return desc;
3702 }
3703
3704 return desc;
3705 }
3706
platform_gpio_count(struct device * dev,const char * con_id)3707 static int platform_gpio_count(struct device *dev, const char *con_id)
3708 {
3709 struct gpiod_lookup_table *table;
3710 struct gpiod_lookup *p;
3711 unsigned int count = 0;
3712
3713 table = gpiod_find_lookup_table(dev);
3714 if (!table)
3715 return -ENOENT;
3716
3717 for (p = &table->table[0]; p->key; p++) {
3718 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3719 (!con_id && !p->con_id))
3720 count++;
3721 }
3722 if (!count)
3723 return -ENOENT;
3724
3725 return count;
3726 }
3727
3728 /**
3729 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3730 * @fwnode: handle of the firmware node
3731 * @con_id: function within the GPIO consumer
3732 * @index: index of the GPIO to obtain for the consumer
3733 * @flags: GPIO initialization flags
3734 * @label: label to attach to the requested GPIO
3735 *
3736 * This function can be used for drivers that get their configuration
3737 * from opaque firmware.
3738 *
3739 * The function properly finds the corresponding GPIO using whatever is the
3740 * underlying firmware interface and then makes sure that the GPIO
3741 * descriptor is requested before it is returned to the caller.
3742 *
3743 * Returns:
3744 * On successful request the GPIO pin is configured in accordance with
3745 * provided @flags.
3746 *
3747 * In case of error an ERR_PTR() is returned.
3748 */
fwnode_gpiod_get_index(struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)3749 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3750 const char *con_id, int index,
3751 enum gpiod_flags flags,
3752 const char *label)
3753 {
3754 struct gpio_desc *desc;
3755 char prop_name[32]; /* 32 is max size of property name */
3756 unsigned int i;
3757
3758 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3759 if (con_id)
3760 snprintf(prop_name, sizeof(prop_name), "%s-%s",
3761 con_id, gpio_suffixes[i]);
3762 else
3763 snprintf(prop_name, sizeof(prop_name), "%s",
3764 gpio_suffixes[i]);
3765
3766 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3767 label);
3768 if (!gpiod_not_found(desc))
3769 break;
3770 }
3771
3772 return desc;
3773 }
3774 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3775
3776 /**
3777 * gpiod_count - return the number of GPIOs associated with a device / function
3778 * or -ENOENT if no GPIO has been assigned to the requested function
3779 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3780 * @con_id: function within the GPIO consumer
3781 */
gpiod_count(struct device * dev,const char * con_id)3782 int gpiod_count(struct device *dev, const char *con_id)
3783 {
3784 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3785 int count = -ENOENT;
3786
3787 if (is_of_node(fwnode))
3788 count = of_gpio_get_count(dev, con_id);
3789 else if (is_acpi_node(fwnode))
3790 count = acpi_gpio_count(dev, con_id);
3791
3792 if (count < 0)
3793 count = platform_gpio_count(dev, con_id);
3794
3795 return count;
3796 }
3797 EXPORT_SYMBOL_GPL(gpiod_count);
3798
3799 /**
3800 * gpiod_get - obtain a GPIO for a given GPIO function
3801 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3802 * @con_id: function within the GPIO consumer
3803 * @flags: optional GPIO initialization flags
3804 *
3805 * Return the GPIO descriptor corresponding to the function con_id of device
3806 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3807 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3808 */
gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)3809 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3810 enum gpiod_flags flags)
3811 {
3812 return gpiod_get_index(dev, con_id, 0, flags);
3813 }
3814 EXPORT_SYMBOL_GPL(gpiod_get);
3815
3816 /**
3817 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3818 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3819 * @con_id: function within the GPIO consumer
3820 * @flags: optional GPIO initialization flags
3821 *
3822 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3823 * the requested function it will return NULL. This is convenient for drivers
3824 * that need to handle optional GPIOs.
3825 */
gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)3826 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3827 const char *con_id,
3828 enum gpiod_flags flags)
3829 {
3830 return gpiod_get_index_optional(dev, con_id, 0, flags);
3831 }
3832 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3833
3834
3835 /**
3836 * gpiod_configure_flags - helper function to configure a given GPIO
3837 * @desc: gpio whose value will be assigned
3838 * @con_id: function within the GPIO consumer
3839 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3840 * of_find_gpio() or of_get_gpio_hog()
3841 * @dflags: gpiod_flags - optional GPIO initialization flags
3842 *
3843 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3844 * requested function and/or index, or another IS_ERR() code if an error
3845 * occurred while trying to acquire the GPIO.
3846 */
gpiod_configure_flags(struct gpio_desc * desc,const char * con_id,unsigned long lflags,enum gpiod_flags dflags)3847 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3848 unsigned long lflags, enum gpiod_flags dflags)
3849 {
3850 int ret;
3851
3852 if (lflags & GPIO_ACTIVE_LOW)
3853 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3854
3855 if (lflags & GPIO_OPEN_DRAIN)
3856 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3857 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3858 /*
3859 * This enforces open drain mode from the consumer side.
3860 * This is necessary for some busses like I2C, but the lookup
3861 * should *REALLY* have specified them as open drain in the
3862 * first place, so print a little warning here.
3863 */
3864 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3865 gpiod_warn(desc,
3866 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3867 }
3868
3869 if (lflags & GPIO_OPEN_SOURCE)
3870 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3871
3872 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3873 gpiod_err(desc,
3874 "both pull-up and pull-down enabled, invalid configuration\n");
3875 return -EINVAL;
3876 }
3877
3878 if (lflags & GPIO_PULL_UP)
3879 set_bit(FLAG_PULL_UP, &desc->flags);
3880 else if (lflags & GPIO_PULL_DOWN)
3881 set_bit(FLAG_PULL_DOWN, &desc->flags);
3882
3883 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3884 if (ret < 0)
3885 return ret;
3886
3887 /* No particular flag request, return here... */
3888 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3889 gpiod_dbg(desc, "no flags found for %s\n", con_id);
3890 return 0;
3891 }
3892
3893 /* Process flags */
3894 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3895 ret = gpiod_direction_output(desc,
3896 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3897 else
3898 ret = gpiod_direction_input(desc);
3899
3900 return ret;
3901 }
3902
3903 /**
3904 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3905 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3906 * @con_id: function within the GPIO consumer
3907 * @idx: index of the GPIO to obtain in the consumer
3908 * @flags: optional GPIO initialization flags
3909 *
3910 * This variant of gpiod_get() allows to access GPIOs other than the first
3911 * defined one for functions that define several GPIOs.
3912 *
3913 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3914 * requested function and/or index, or another IS_ERR() code if an error
3915 * occurred while trying to acquire the GPIO.
3916 */
gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)3917 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3918 const char *con_id,
3919 unsigned int idx,
3920 enum gpiod_flags flags)
3921 {
3922 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3923 struct gpio_desc *desc = NULL;
3924 int ret;
3925 /* Maybe we have a device name, maybe not */
3926 const char *devname = dev ? dev_name(dev) : "?";
3927 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3928
3929 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3930
3931 /* Using device tree? */
3932 if (is_of_node(fwnode)) {
3933 dev_dbg(dev, "using device tree for GPIO lookup\n");
3934 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3935 } else if (is_acpi_node(fwnode)) {
3936 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3937 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3938 }
3939
3940 /*
3941 * Either we are not using DT or ACPI, or their lookup did not return
3942 * a result. In that case, use platform lookup as a fallback.
3943 */
3944 if (!desc || gpiod_not_found(desc)) {
3945 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3946 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3947 }
3948
3949 if (IS_ERR(desc)) {
3950 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3951 return desc;
3952 }
3953
3954 /*
3955 * If a connection label was passed use that, else attempt to use
3956 * the device name as label
3957 */
3958 ret = gpiod_request(desc, con_id ? con_id : devname);
3959 if (ret) {
3960 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
3961 /*
3962 * This happens when there are several consumers for
3963 * the same GPIO line: we just return here without
3964 * further initialization. It is a bit if a hack.
3965 * This is necessary to support fixed regulators.
3966 *
3967 * FIXME: Make this more sane and safe.
3968 */
3969 dev_info(dev, "nonexclusive access to GPIO for %s\n",
3970 con_id ? con_id : devname);
3971 return desc;
3972 } else {
3973 return ERR_PTR(ret);
3974 }
3975 }
3976
3977 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3978 if (ret < 0) {
3979 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3980 gpiod_put(desc);
3981 return ERR_PTR(ret);
3982 }
3983
3984 blocking_notifier_call_chain(&desc->gdev->notifier,
3985 GPIOLINE_CHANGED_REQUESTED, desc);
3986
3987 return desc;
3988 }
3989 EXPORT_SYMBOL_GPL(gpiod_get_index);
3990
3991 /**
3992 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3993 * @fwnode: handle of the firmware node
3994 * @propname: name of the firmware property representing the GPIO
3995 * @index: index of the GPIO to obtain for the consumer
3996 * @dflags: GPIO initialization flags
3997 * @label: label to attach to the requested GPIO
3998 *
3999 * This function can be used for drivers that get their configuration
4000 * from opaque firmware.
4001 *
4002 * The function properly finds the corresponding GPIO using whatever is the
4003 * underlying firmware interface and then makes sure that the GPIO
4004 * descriptor is requested before it is returned to the caller.
4005 *
4006 * Returns:
4007 * On successful request the GPIO pin is configured in accordance with
4008 * provided @dflags.
4009 *
4010 * In case of error an ERR_PTR() is returned.
4011 */
fwnode_get_named_gpiod(struct fwnode_handle * fwnode,const char * propname,int index,enum gpiod_flags dflags,const char * label)4012 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4013 const char *propname, int index,
4014 enum gpiod_flags dflags,
4015 const char *label)
4016 {
4017 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4018 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4019 int ret;
4020
4021 if (is_of_node(fwnode)) {
4022 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4023 propname, index,
4024 dflags,
4025 label);
4026 return desc;
4027 } else if (is_acpi_node(fwnode)) {
4028 struct acpi_gpio_info info;
4029
4030 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4031 if (IS_ERR(desc))
4032 return desc;
4033
4034 acpi_gpio_update_gpiod_flags(&dflags, &info);
4035 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4036 } else
4037 return ERR_PTR(-EINVAL);
4038
4039 /* Currently only ACPI takes this path */
4040 ret = gpiod_request(desc, label);
4041 if (ret)
4042 return ERR_PTR(ret);
4043
4044 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4045 if (ret < 0) {
4046 gpiod_put(desc);
4047 return ERR_PTR(ret);
4048 }
4049
4050 blocking_notifier_call_chain(&desc->gdev->notifier,
4051 GPIOLINE_CHANGED_REQUESTED, desc);
4052
4053 return desc;
4054 }
4055 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4056
4057 /**
4058 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4059 * function
4060 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4061 * @con_id: function within the GPIO consumer
4062 * @index: index of the GPIO to obtain in the consumer
4063 * @flags: optional GPIO initialization flags
4064 *
4065 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4066 * specified index was assigned to the requested function it will return NULL.
4067 * This is convenient for drivers that need to handle optional GPIOs.
4068 */
gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)4069 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4070 const char *con_id,
4071 unsigned int index,
4072 enum gpiod_flags flags)
4073 {
4074 struct gpio_desc *desc;
4075
4076 desc = gpiod_get_index(dev, con_id, index, flags);
4077 if (gpiod_not_found(desc))
4078 return NULL;
4079
4080 return desc;
4081 }
4082 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4083
4084 /**
4085 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4086 * @desc: gpio whose value will be assigned
4087 * @name: gpio line name
4088 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4089 * of_find_gpio() or of_get_gpio_hog()
4090 * @dflags: gpiod_flags - optional GPIO initialization flags
4091 */
gpiod_hog(struct gpio_desc * desc,const char * name,unsigned long lflags,enum gpiod_flags dflags)4092 int gpiod_hog(struct gpio_desc *desc, const char *name,
4093 unsigned long lflags, enum gpiod_flags dflags)
4094 {
4095 struct gpio_chip *gc;
4096 struct gpio_desc *local_desc;
4097 int hwnum;
4098 int ret;
4099
4100 gc = gpiod_to_chip(desc);
4101 hwnum = gpio_chip_hwgpio(desc);
4102
4103 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4104 lflags, dflags);
4105 if (IS_ERR(local_desc)) {
4106 ret = PTR_ERR(local_desc);
4107 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4108 name, gc->label, hwnum, ret);
4109 return ret;
4110 }
4111
4112 /* Mark GPIO as hogged so it can be identified and removed later */
4113 set_bit(FLAG_IS_HOGGED, &desc->flags);
4114
4115 gpiod_info(desc, "hogged as %s%s\n",
4116 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4117 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4118 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4119
4120 return 0;
4121 }
4122
4123 /**
4124 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4125 * @gc: gpio chip to act on
4126 */
gpiochip_free_hogs(struct gpio_chip * gc)4127 static void gpiochip_free_hogs(struct gpio_chip *gc)
4128 {
4129 int id;
4130
4131 for (id = 0; id < gc->ngpio; id++) {
4132 if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
4133 gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
4134 }
4135 }
4136
4137 /**
4138 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4139 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4140 * @con_id: function within the GPIO consumer
4141 * @flags: optional GPIO initialization flags
4142 *
4143 * This function acquires all the GPIOs defined under a given function.
4144 *
4145 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4146 * no GPIO has been assigned to the requested function, or another IS_ERR()
4147 * code if an error occurred while trying to acquire the GPIOs.
4148 */
gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)4149 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4150 const char *con_id,
4151 enum gpiod_flags flags)
4152 {
4153 struct gpio_desc *desc;
4154 struct gpio_descs *descs;
4155 struct gpio_array *array_info = NULL;
4156 struct gpio_chip *gc;
4157 int count, bitmap_size;
4158
4159 count = gpiod_count(dev, con_id);
4160 if (count < 0)
4161 return ERR_PTR(count);
4162
4163 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4164 if (!descs)
4165 return ERR_PTR(-ENOMEM);
4166
4167 for (descs->ndescs = 0; descs->ndescs < count; ) {
4168 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4169 if (IS_ERR(desc)) {
4170 gpiod_put_array(descs);
4171 return ERR_CAST(desc);
4172 }
4173
4174 descs->desc[descs->ndescs] = desc;
4175
4176 gc = gpiod_to_chip(desc);
4177 /*
4178 * If pin hardware number of array member 0 is also 0, select
4179 * its chip as a candidate for fast bitmap processing path.
4180 */
4181 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4182 struct gpio_descs *array;
4183
4184 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4185 gc->ngpio : count);
4186
4187 array = kzalloc(struct_size(descs, desc, count) +
4188 struct_size(array_info, invert_mask,
4189 3 * bitmap_size), GFP_KERNEL);
4190 if (!array) {
4191 gpiod_put_array(descs);
4192 return ERR_PTR(-ENOMEM);
4193 }
4194
4195 memcpy(array, descs,
4196 struct_size(descs, desc, descs->ndescs + 1));
4197 kfree(descs);
4198
4199 descs = array;
4200 array_info = (void *)(descs->desc + count);
4201 array_info->get_mask = array_info->invert_mask +
4202 bitmap_size;
4203 array_info->set_mask = array_info->get_mask +
4204 bitmap_size;
4205
4206 array_info->desc = descs->desc;
4207 array_info->size = count;
4208 array_info->chip = gc;
4209 bitmap_set(array_info->get_mask, descs->ndescs,
4210 count - descs->ndescs);
4211 bitmap_set(array_info->set_mask, descs->ndescs,
4212 count - descs->ndescs);
4213 descs->info = array_info;
4214 }
4215 /* Unmark array members which don't belong to the 'fast' chip */
4216 if (array_info && array_info->chip != gc) {
4217 __clear_bit(descs->ndescs, array_info->get_mask);
4218 __clear_bit(descs->ndescs, array_info->set_mask);
4219 }
4220 /*
4221 * Detect array members which belong to the 'fast' chip
4222 * but their pins are not in hardware order.
4223 */
4224 else if (array_info &&
4225 gpio_chip_hwgpio(desc) != descs->ndescs) {
4226 /*
4227 * Don't use fast path if all array members processed so
4228 * far belong to the same chip as this one but its pin
4229 * hardware number is different from its array index.
4230 */
4231 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4232 array_info = NULL;
4233 } else {
4234 __clear_bit(descs->ndescs,
4235 array_info->get_mask);
4236 __clear_bit(descs->ndescs,
4237 array_info->set_mask);
4238 }
4239 } else if (array_info) {
4240 /* Exclude open drain or open source from fast output */
4241 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4242 gpiochip_line_is_open_source(gc, descs->ndescs))
4243 __clear_bit(descs->ndescs,
4244 array_info->set_mask);
4245 /* Identify 'fast' pins which require invertion */
4246 if (gpiod_is_active_low(desc))
4247 __set_bit(descs->ndescs,
4248 array_info->invert_mask);
4249 }
4250
4251 descs->ndescs++;
4252 }
4253 if (array_info)
4254 dev_dbg(dev,
4255 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4256 array_info->chip->label, array_info->size,
4257 *array_info->get_mask, *array_info->set_mask,
4258 *array_info->invert_mask);
4259 return descs;
4260 }
4261 EXPORT_SYMBOL_GPL(gpiod_get_array);
4262
4263 /**
4264 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4265 * function
4266 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4267 * @con_id: function within the GPIO consumer
4268 * @flags: optional GPIO initialization flags
4269 *
4270 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4271 * assigned to the requested function it will return NULL.
4272 */
gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4273 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4274 const char *con_id,
4275 enum gpiod_flags flags)
4276 {
4277 struct gpio_descs *descs;
4278
4279 descs = gpiod_get_array(dev, con_id, flags);
4280 if (gpiod_not_found(descs))
4281 return NULL;
4282
4283 return descs;
4284 }
4285 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4286
4287 /**
4288 * gpiod_put - dispose of a GPIO descriptor
4289 * @desc: GPIO descriptor to dispose of
4290 *
4291 * No descriptor can be used after gpiod_put() has been called on it.
4292 */
gpiod_put(struct gpio_desc * desc)4293 void gpiod_put(struct gpio_desc *desc)
4294 {
4295 if (desc)
4296 gpiod_free(desc);
4297 }
4298 EXPORT_SYMBOL_GPL(gpiod_put);
4299
4300 /**
4301 * gpiod_put_array - dispose of multiple GPIO descriptors
4302 * @descs: struct gpio_descs containing an array of descriptors
4303 */
gpiod_put_array(struct gpio_descs * descs)4304 void gpiod_put_array(struct gpio_descs *descs)
4305 {
4306 unsigned int i;
4307
4308 for (i = 0; i < descs->ndescs; i++)
4309 gpiod_put(descs->desc[i]);
4310
4311 kfree(descs);
4312 }
4313 EXPORT_SYMBOL_GPL(gpiod_put_array);
4314
4315
gpio_bus_match(struct device * dev,struct device_driver * drv)4316 static int gpio_bus_match(struct device *dev, struct device_driver *drv)
4317 {
4318 struct fwnode_handle *fwnode = dev_fwnode(dev);
4319
4320 /*
4321 * Only match if the fwnode doesn't already have a proper struct device
4322 * created for it.
4323 */
4324 if (fwnode && fwnode->dev != dev)
4325 return 0;
4326 return 1;
4327 }
4328
gpio_stub_drv_probe(struct device * dev)4329 static int gpio_stub_drv_probe(struct device *dev)
4330 {
4331 /*
4332 * The DT node of some GPIO chips have a "compatible" property, but
4333 * never have a struct device added and probed by a driver to register
4334 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4335 * the consumers of the GPIO chip to get probe deferred forever because
4336 * they will be waiting for a device associated with the GPIO chip
4337 * firmware node to get added and bound to a driver.
4338 *
4339 * To allow these consumers to probe, we associate the struct
4340 * gpio_device of the GPIO chip with the firmware node and then simply
4341 * bind it to this stub driver.
4342 */
4343 return 0;
4344 }
4345
4346 static struct device_driver gpio_stub_drv = {
4347 .name = "gpio_stub_drv",
4348 .bus = &gpio_bus_type,
4349 .probe = gpio_stub_drv_probe,
4350 };
4351
gpiolib_dev_init(void)4352 static int __init gpiolib_dev_init(void)
4353 {
4354 int ret;
4355
4356 /* Register GPIO sysfs bus */
4357 ret = bus_register(&gpio_bus_type);
4358 if (ret < 0) {
4359 pr_err("gpiolib: could not register GPIO bus type\n");
4360 return ret;
4361 }
4362
4363 ret = driver_register(&gpio_stub_drv);
4364 if (ret < 0) {
4365 pr_err("gpiolib: could not register GPIO stub driver\n");
4366 bus_unregister(&gpio_bus_type);
4367 return ret;
4368 }
4369
4370 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4371 if (ret < 0) {
4372 pr_err("gpiolib: failed to allocate char dev region\n");
4373 driver_unregister(&gpio_stub_drv);
4374 bus_unregister(&gpio_bus_type);
4375 return ret;
4376 }
4377
4378 gpiolib_initialized = true;
4379 gpiochip_setup_devs();
4380
4381 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4382 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4383 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4384
4385 return ret;
4386 }
4387 core_initcall(gpiolib_dev_init);
4388
4389 #ifdef CONFIG_DEBUG_FS
4390
gpiolib_dbg_show(struct seq_file * s,struct gpio_device * gdev)4391 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4392 {
4393 unsigned i;
4394 struct gpio_chip *gc = gdev->chip;
4395 unsigned gpio = gdev->base;
4396 struct gpio_desc *gdesc = &gdev->descs[0];
4397 bool is_out;
4398 bool is_irq;
4399 bool active_low;
4400
4401 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4402 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4403 if (gdesc->name) {
4404 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4405 gpio, gdesc->name);
4406 }
4407 continue;
4408 }
4409
4410 gpiod_get_direction(gdesc);
4411 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4412 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4413 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4414 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4415 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4416 is_out ? "out" : "in ",
4417 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
4418 is_irq ? "IRQ " : "",
4419 active_low ? "ACTIVE LOW" : "");
4420 seq_printf(s, "\n");
4421 }
4422 }
4423
gpiolib_seq_start(struct seq_file * s,loff_t * pos)4424 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4425 {
4426 unsigned long flags;
4427 struct gpio_device *gdev = NULL;
4428 loff_t index = *pos;
4429
4430 s->private = "";
4431
4432 spin_lock_irqsave(&gpio_lock, flags);
4433 list_for_each_entry(gdev, &gpio_devices, list)
4434 if (index-- == 0) {
4435 spin_unlock_irqrestore(&gpio_lock, flags);
4436 return gdev;
4437 }
4438 spin_unlock_irqrestore(&gpio_lock, flags);
4439
4440 return NULL;
4441 }
4442
gpiolib_seq_next(struct seq_file * s,void * v,loff_t * pos)4443 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4444 {
4445 unsigned long flags;
4446 struct gpio_device *gdev = v;
4447 void *ret = NULL;
4448
4449 spin_lock_irqsave(&gpio_lock, flags);
4450 if (list_is_last(&gdev->list, &gpio_devices))
4451 ret = NULL;
4452 else
4453 ret = list_entry(gdev->list.next, struct gpio_device, list);
4454 spin_unlock_irqrestore(&gpio_lock, flags);
4455
4456 s->private = "\n";
4457 ++*pos;
4458
4459 return ret;
4460 }
4461
gpiolib_seq_stop(struct seq_file * s,void * v)4462 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4463 {
4464 }
4465
gpiolib_seq_show(struct seq_file * s,void * v)4466 static int gpiolib_seq_show(struct seq_file *s, void *v)
4467 {
4468 struct gpio_device *gdev = v;
4469 struct gpio_chip *gc = gdev->chip;
4470 struct device *parent;
4471
4472 if (!gc) {
4473 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4474 dev_name(&gdev->dev));
4475 return 0;
4476 }
4477
4478 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4479 dev_name(&gdev->dev),
4480 gdev->base, gdev->base + gdev->ngpio - 1);
4481 parent = gc->parent;
4482 if (parent)
4483 seq_printf(s, ", parent: %s/%s",
4484 parent->bus ? parent->bus->name : "no-bus",
4485 dev_name(parent));
4486 if (gc->label)
4487 seq_printf(s, ", %s", gc->label);
4488 if (gc->can_sleep)
4489 seq_printf(s, ", can sleep");
4490 seq_printf(s, ":\n");
4491
4492 if (gc->dbg_show)
4493 gc->dbg_show(s, gc);
4494 else
4495 gpiolib_dbg_show(s, gdev);
4496
4497 return 0;
4498 }
4499
4500 static const struct seq_operations gpiolib_sops = {
4501 .start = gpiolib_seq_start,
4502 .next = gpiolib_seq_next,
4503 .stop = gpiolib_seq_stop,
4504 .show = gpiolib_seq_show,
4505 };
4506 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4507
gpiolib_debugfs_init(void)4508 static int __init gpiolib_debugfs_init(void)
4509 {
4510 /* /sys/kernel/debug/gpio */
4511 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4512 return 0;
4513 }
4514 subsys_initcall(gpiolib_debugfs_init);
4515
4516 #endif /* DEBUG_FS */
4517