1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/interrupt.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/device.h>
9 #include <linux/debugfs.h>
10 #include <linux/seq_file.h>
11 #include <linux/gpio.h>
12 #include <linux/of_gpio.h>
13 #include <linux/idr.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/gpio/machine.h>
18 #include <linux/pinctrl/consumer.h>
22 #define CREATE_TRACE_POINTS
23 #include <trace/events/gpio.h>
25 /* Implementation infrastructure for GPIO interfaces.
27 * The GPIO programming interface allows for inlining speed-critical
28 * get/set operations for common cases, so that access to SOC-integrated
29 * GPIOs can sometimes cost only an instruction or two per bit.
33 /* When debugging, extend minimal trust to callers and platform code.
34 * Also emit diagnostic messages that may help initial bringup, when
35 * board setup or driver bugs are most common.
37 * Otherwise, minimize overhead in what may be bitbanging codepaths.
40 #define extra_checks 1
42 #define extra_checks 0
45 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
46 * While any GPIO is requested, its gpio_chip is not removable;
47 * each GPIO's "requested" flag serves as a lock and refcount.
49 DEFINE_SPINLOCK(gpio_lock);
51 static DEFINE_MUTEX(gpio_lookup_lock);
52 static LIST_HEAD(gpio_lookup_list);
53 LIST_HEAD(gpio_chips);
56 static void gpiochip_free_hogs(struct gpio_chip *chip);
57 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
60 static inline void desc_set_label(struct gpio_desc *d, const char *label)
66 * Convert a GPIO number to its descriptor
68 struct gpio_desc *gpio_to_desc(unsigned gpio)
70 struct gpio_chip *chip;
73 spin_lock_irqsave(&gpio_lock, flags);
75 list_for_each_entry(chip, &gpio_chips, list) {
76 if (chip->base <= gpio && chip->base + chip->ngpio > gpio) {
77 spin_unlock_irqrestore(&gpio_lock, flags);
78 return &chip->desc[gpio - chip->base];
82 spin_unlock_irqrestore(&gpio_lock, flags);
84 if (!gpio_is_valid(gpio))
85 WARN(1, "invalid GPIO %d\n", gpio);
89 EXPORT_SYMBOL_GPL(gpio_to_desc);
92 * Get the GPIO descriptor corresponding to the given hw number for this chip.
94 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
97 if (hwnum >= chip->ngpio)
98 return ERR_PTR(-EINVAL);
100 return &chip->desc[hwnum];
104 * Convert a GPIO descriptor to the integer namespace.
105 * This should disappear in the future but is needed since we still
106 * use GPIO numbers for error messages and sysfs nodes
108 int desc_to_gpio(const struct gpio_desc *desc)
110 return desc->chip->base + (desc - &desc->chip->desc[0]);
112 EXPORT_SYMBOL_GPL(desc_to_gpio);
116 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
117 * @desc: descriptor to return the chip of
119 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
121 return desc ? desc->chip : NULL;
123 EXPORT_SYMBOL_GPL(gpiod_to_chip);
125 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
126 static int gpiochip_find_base(int ngpio)
128 struct gpio_chip *chip;
129 int base = ARCH_NR_GPIOS - ngpio;
131 list_for_each_entry_reverse(chip, &gpio_chips, list) {
132 /* found a free space? */
133 if (chip->base + chip->ngpio <= base)
136 /* nope, check the space right before the chip */
137 base = chip->base - ngpio;
140 if (gpio_is_valid(base)) {
141 pr_debug("%s: found new base at %d\n", __func__, base);
144 pr_err("%s: cannot find free range\n", __func__);
150 * gpiod_get_direction - return the current direction of a GPIO
151 * @desc: GPIO to get the direction of
153 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
155 * This function may sleep if gpiod_cansleep() is true.
157 int gpiod_get_direction(struct gpio_desc *desc)
159 struct gpio_chip *chip;
161 int status = -EINVAL;
163 chip = gpiod_to_chip(desc);
164 offset = gpio_chip_hwgpio(desc);
166 if (!chip->get_direction)
169 status = chip->get_direction(chip, offset);
171 /* GPIOF_DIR_IN, or other positive */
173 clear_bit(FLAG_IS_OUT, &desc->flags);
177 set_bit(FLAG_IS_OUT, &desc->flags);
181 EXPORT_SYMBOL_GPL(gpiod_get_direction);
184 * Add a new chip to the global chips list, keeping the list of chips sorted
187 * Return -EBUSY if the new chip overlaps with some other chip's integer
190 static int gpiochip_add_to_list(struct gpio_chip *chip)
192 struct list_head *pos;
193 struct gpio_chip *_chip;
196 /* find where to insert our chip */
197 list_for_each(pos, &gpio_chips) {
198 _chip = list_entry(pos, struct gpio_chip, list);
199 /* shall we insert before _chip? */
200 if (_chip->base >= chip->base + chip->ngpio)
204 /* are we stepping on the chip right before? */
205 if (pos != &gpio_chips && pos->prev != &gpio_chips) {
206 _chip = list_entry(pos->prev, struct gpio_chip, list);
207 if (_chip->base + _chip->ngpio > chip->base) {
208 dev_err(chip->parent,
209 "GPIO integer space overlap, cannot add chip\n");
215 list_add_tail(&chip->list, pos);
221 * Convert a GPIO name to its descriptor
223 static struct gpio_desc *gpio_name_to_desc(const char * const name)
225 struct gpio_chip *chip;
228 spin_lock_irqsave(&gpio_lock, flags);
230 list_for_each_entry(chip, &gpio_chips, list) {
233 for (i = 0; i != chip->ngpio; ++i) {
234 struct gpio_desc *gpio = &chip->desc[i];
239 if (!strcmp(gpio->name, name)) {
240 spin_unlock_irqrestore(&gpio_lock, flags);
246 spin_unlock_irqrestore(&gpio_lock, flags);
252 * Takes the names from gc->names and checks if they are all unique. If they
253 * are, they are assigned to their gpio descriptors.
255 * Warning if one of the names is already used for a different GPIO.
257 static int gpiochip_set_desc_names(struct gpio_chip *gc)
264 /* First check all names if they are unique */
265 for (i = 0; i != gc->ngpio; ++i) {
266 struct gpio_desc *gpio;
268 gpio = gpio_name_to_desc(gc->names[i]);
270 dev_warn(gc->parent, "Detected name collision for "
275 /* Then add all names to the GPIO descriptors */
276 for (i = 0; i != gc->ngpio; ++i)
277 gc->desc[i].name = gc->names[i];
283 * gpiochip_add() - register a gpio_chip
284 * @chip: the chip to register, with chip->base initialized
285 * Context: potentially before irqs will work
287 * Returns a negative errno if the chip can't be registered, such as
288 * because the chip->base is invalid or already associated with a
289 * different chip. Otherwise it returns zero as a success code.
291 * When gpiochip_add() is called very early during boot, so that GPIOs
292 * can be freely used, the chip->dev device must be registered before
293 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
294 * for GPIOs will fail rudely.
296 * If chip->base is negative, this requests dynamic assignment of
297 * a range of valid GPIOs.
299 int gpiochip_add(struct gpio_chip *chip)
304 int base = chip->base;
305 struct gpio_desc *descs;
307 descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL);
311 spin_lock_irqsave(&gpio_lock, flags);
314 base = gpiochip_find_base(chip->ngpio);
317 spin_unlock_irqrestore(&gpio_lock, flags);
323 status = gpiochip_add_to_list(chip);
325 spin_unlock_irqrestore(&gpio_lock, flags);
329 for (id = 0; id < chip->ngpio; id++) {
330 struct gpio_desc *desc = &descs[id];
334 /* REVISIT: most hardware initializes GPIOs as inputs (often
335 * with pullups enabled) so power usage is minimized. Linux
336 * code should set the gpio direction first thing; but until
337 * it does, and in case chip->get_direction is not set, we may
338 * expose the wrong direction in sysfs.
340 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
345 spin_unlock_irqrestore(&gpio_lock, flags);
347 #ifdef CONFIG_PINCTRL
348 INIT_LIST_HEAD(&chip->pin_ranges);
351 if (!chip->owner && chip->parent && chip->parent->driver)
352 chip->owner = chip->parent->driver->owner;
354 status = gpiochip_set_desc_names(chip);
356 goto err_remove_from_list;
358 status = of_gpiochip_add(chip);
360 goto err_remove_chip;
362 acpi_gpiochip_add(chip);
364 status = gpiochip_sysfs_register(chip);
366 goto err_remove_chip;
368 pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
369 chip->base, chip->base + chip->ngpio - 1,
370 chip->label ? : "generic");
375 acpi_gpiochip_remove(chip);
376 gpiochip_free_hogs(chip);
377 of_gpiochip_remove(chip);
378 err_remove_from_list:
379 spin_lock_irqsave(&gpio_lock, flags);
380 list_del(&chip->list);
381 spin_unlock_irqrestore(&gpio_lock, flags);
386 /* failures here can mean systems won't boot... */
387 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
388 chip->base, chip->base + chip->ngpio - 1,
389 chip->label ? : "generic");
392 EXPORT_SYMBOL_GPL(gpiochip_add);
395 * gpiochip_remove() - unregister a gpio_chip
396 * @chip: the chip to unregister
398 * A gpio_chip with any GPIOs still requested may not be removed.
400 void gpiochip_remove(struct gpio_chip *chip)
402 struct gpio_desc *desc;
405 bool requested = false;
407 gpiochip_sysfs_unregister(chip);
409 gpiochip_irqchip_remove(chip);
411 acpi_gpiochip_remove(chip);
412 gpiochip_remove_pin_ranges(chip);
413 gpiochip_free_hogs(chip);
414 of_gpiochip_remove(chip);
416 spin_lock_irqsave(&gpio_lock, flags);
417 for (id = 0; id < chip->ngpio; id++) {
418 desc = &chip->desc[id];
420 if (test_bit(FLAG_REQUESTED, &desc->flags))
423 list_del(&chip->list);
424 spin_unlock_irqrestore(&gpio_lock, flags);
427 dev_crit(chip->parent,
428 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
433 EXPORT_SYMBOL_GPL(gpiochip_remove);
436 * gpiochip_find() - iterator for locating a specific gpio_chip
437 * @data: data to pass to match function
438 * @callback: Callback function to check gpio_chip
440 * Similar to bus_find_device. It returns a reference to a gpio_chip as
441 * determined by a user supplied @match callback. The callback should return
442 * 0 if the device doesn't match and non-zero if it does. If the callback is
443 * non-zero, this function will return to the caller and not iterate over any
446 struct gpio_chip *gpiochip_find(void *data,
447 int (*match)(struct gpio_chip *chip,
450 struct gpio_chip *chip;
453 spin_lock_irqsave(&gpio_lock, flags);
454 list_for_each_entry(chip, &gpio_chips, list)
455 if (match(chip, data))
459 if (&chip->list == &gpio_chips)
461 spin_unlock_irqrestore(&gpio_lock, flags);
465 EXPORT_SYMBOL_GPL(gpiochip_find);
467 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
469 const char *name = data;
471 return !strcmp(chip->label, name);
474 static struct gpio_chip *find_chip_by_name(const char *name)
476 return gpiochip_find((void *)name, gpiochip_match_name);
479 #ifdef CONFIG_GPIOLIB_IRQCHIP
482 * The following is irqchip helper code for gpiochips.
486 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
487 * @gpiochip: the gpiochip to set the irqchip chain to
488 * @irqchip: the irqchip to chain to the gpiochip
489 * @parent_irq: the irq number corresponding to the parent IRQ for this
491 * @parent_handler: the parent interrupt handler for the accumulated IRQ
492 * coming out of the gpiochip. If the interrupt is nested rather than
493 * cascaded, pass NULL in this handler argument
495 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
496 struct irq_chip *irqchip,
498 irq_flow_handler_t parent_handler)
502 if (!gpiochip->irqdomain) {
503 chip_err(gpiochip, "called %s before setting up irqchip\n",
508 if (parent_handler) {
509 if (gpiochip->can_sleep) {
511 "you cannot have chained interrupts on a "
512 "chip that may sleep\n");
516 * The parent irqchip is already using the chip_data for this
517 * irqchip, so our callbacks simply use the handler_data.
519 irq_set_chained_handler_and_data(parent_irq, parent_handler,
522 gpiochip->irq_parent = parent_irq;
525 /* Set the parent IRQ for all affected IRQs */
526 for (offset = 0; offset < gpiochip->ngpio; offset++)
527 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
530 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
533 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
534 * @d: the irqdomain used by this irqchip
535 * @irq: the global irq number used by this GPIO irqchip irq
536 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
538 * This function will set up the mapping for a certain IRQ line on a
539 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
540 * stored inside the gpiochip.
542 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
543 irq_hw_number_t hwirq)
545 struct gpio_chip *chip = d->host_data;
547 irq_set_chip_data(irq, chip);
549 * This lock class tells lockdep that GPIO irqs are in a different
550 * category than their parents, so it won't report false recursion.
552 irq_set_lockdep_class(irq, chip->lock_key);
553 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
554 /* Chips that can sleep need nested thread handlers */
555 if (chip->can_sleep && !chip->irq_not_threaded)
556 irq_set_nested_thread(irq, 1);
557 irq_set_noprobe(irq);
560 * No set-up of the hardware will happen if IRQ_TYPE_NONE
561 * is passed as default type.
563 if (chip->irq_default_type != IRQ_TYPE_NONE)
564 irq_set_irq_type(irq, chip->irq_default_type);
569 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
571 struct gpio_chip *chip = d->host_data;
574 irq_set_nested_thread(irq, 0);
575 irq_set_chip_and_handler(irq, NULL, NULL);
576 irq_set_chip_data(irq, NULL);
579 static const struct irq_domain_ops gpiochip_domain_ops = {
580 .map = gpiochip_irq_map,
581 .unmap = gpiochip_irq_unmap,
582 /* Virtually all GPIO irqchips are twocell:ed */
583 .xlate = irq_domain_xlate_twocell,
586 static int gpiochip_irq_reqres(struct irq_data *d)
588 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
590 if (!try_module_get(chip->owner))
593 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
595 "unable to lock HW IRQ %lu for IRQ\n",
597 module_put(chip->owner);
603 static void gpiochip_irq_relres(struct irq_data *d)
605 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
607 gpiochip_unlock_as_irq(chip, d->hwirq);
608 module_put(chip->owner);
611 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
613 return irq_find_mapping(chip->irqdomain, offset);
617 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
618 * @gpiochip: the gpiochip to remove the irqchip from
620 * This is called only from gpiochip_remove()
622 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
626 acpi_gpiochip_free_interrupts(gpiochip);
628 if (gpiochip->irq_parent) {
629 irq_set_chained_handler(gpiochip->irq_parent, NULL);
630 irq_set_handler_data(gpiochip->irq_parent, NULL);
633 /* Remove all IRQ mappings and delete the domain */
634 if (gpiochip->irqdomain) {
635 for (offset = 0; offset < gpiochip->ngpio; offset++)
637 irq_find_mapping(gpiochip->irqdomain, offset));
638 irq_domain_remove(gpiochip->irqdomain);
641 if (gpiochip->irqchip) {
642 gpiochip->irqchip->irq_request_resources = NULL;
643 gpiochip->irqchip->irq_release_resources = NULL;
644 gpiochip->irqchip = NULL;
649 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
650 * @gpiochip: the gpiochip to add the irqchip to
651 * @irqchip: the irqchip to add to the gpiochip
652 * @first_irq: if not dynamically assigned, the base (first) IRQ to
653 * allocate gpiochip irqs from
654 * @handler: the irq handler to use (often a predefined irq core function)
655 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
656 * to have the core avoid setting up any default type in the hardware.
657 * @lock_key: lockdep class
659 * This function closely associates a certain irqchip with a certain
660 * gpiochip, providing an irq domain to translate the local IRQs to
661 * global irqs in the gpiolib core, and making sure that the gpiochip
662 * is passed as chip data to all related functions. Driver callbacks
663 * need to use container_of() to get their local state containers back
664 * from the gpiochip passed as chip data. An irqdomain will be stored
665 * in the gpiochip that shall be used by the driver to handle IRQ number
666 * translation. The gpiochip will need to be initialized and registered
667 * before calling this function.
669 * This function will handle two cell:ed simple IRQs and assumes all
670 * the pins on the gpiochip can generate a unique IRQ. Everything else
671 * need to be open coded.
673 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
674 struct irq_chip *irqchip,
675 unsigned int first_irq,
676 irq_flow_handler_t handler,
678 struct lock_class_key *lock_key)
680 struct device_node *of_node;
682 unsigned irq_base = 0;
684 if (!gpiochip || !irqchip)
687 if (!gpiochip->parent) {
688 pr_err("missing gpiochip .dev parent pointer\n");
691 of_node = gpiochip->parent->of_node;
692 #ifdef CONFIG_OF_GPIO
694 * If the gpiochip has an assigned OF node this takes precedence
695 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
697 if (gpiochip->of_node)
698 of_node = gpiochip->of_node;
700 gpiochip->irqchip = irqchip;
701 gpiochip->irq_handler = handler;
702 gpiochip->irq_default_type = type;
703 gpiochip->to_irq = gpiochip_to_irq;
704 gpiochip->lock_key = lock_key;
705 gpiochip->irqdomain = irq_domain_add_simple(of_node,
706 gpiochip->ngpio, first_irq,
707 &gpiochip_domain_ops, gpiochip);
708 if (!gpiochip->irqdomain) {
709 gpiochip->irqchip = NULL;
714 * It is possible for a driver to override this, but only if the
715 * alternative functions are both implemented.
717 if (!irqchip->irq_request_resources &&
718 !irqchip->irq_release_resources) {
719 irqchip->irq_request_resources = gpiochip_irq_reqres;
720 irqchip->irq_release_resources = gpiochip_irq_relres;
724 * Prepare the mapping since the irqchip shall be orthogonal to
725 * any gpiochip calls. If the first_irq was zero, this is
726 * necessary to allocate descriptors for all IRQs.
728 for (offset = 0; offset < gpiochip->ngpio; offset++) {
729 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
732 * Store the base into the gpiochip to be used when
733 * unmapping the irqs.
735 gpiochip->irq_base = irq_base;
738 acpi_gpiochip_request_interrupts(gpiochip);
742 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
744 #else /* CONFIG_GPIOLIB_IRQCHIP */
746 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
748 #endif /* CONFIG_GPIOLIB_IRQCHIP */
751 * gpiochip_generic_request() - request the gpio function for a pin
752 * @chip: the gpiochip owning the GPIO
753 * @offset: the offset of the GPIO to request for GPIO function
755 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
757 return pinctrl_request_gpio(chip->base + offset);
759 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
762 * gpiochip_generic_free() - free the gpio function from a pin
763 * @chip: the gpiochip to request the gpio function for
764 * @offset: the offset of the GPIO to free from GPIO function
766 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
768 pinctrl_free_gpio(chip->base + offset);
770 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
772 #ifdef CONFIG_PINCTRL
775 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
776 * @chip: the gpiochip to add the range for
777 * @pctldev: the pin controller to map to
778 * @gpio_offset: the start offset in the current gpio_chip number space
779 * @pin_group: name of the pin group inside the pin controller
781 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
782 struct pinctrl_dev *pctldev,
783 unsigned int gpio_offset, const char *pin_group)
785 struct gpio_pin_range *pin_range;
788 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
790 chip_err(chip, "failed to allocate pin ranges\n");
794 /* Use local offset as range ID */
795 pin_range->range.id = gpio_offset;
796 pin_range->range.gc = chip;
797 pin_range->range.name = chip->label;
798 pin_range->range.base = chip->base + gpio_offset;
799 pin_range->pctldev = pctldev;
801 ret = pinctrl_get_group_pins(pctldev, pin_group,
802 &pin_range->range.pins,
803 &pin_range->range.npins);
809 pinctrl_add_gpio_range(pctldev, &pin_range->range);
811 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
812 gpio_offset, gpio_offset + pin_range->range.npins - 1,
813 pinctrl_dev_get_devname(pctldev), pin_group);
815 list_add_tail(&pin_range->node, &chip->pin_ranges);
819 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
822 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
823 * @chip: the gpiochip to add the range for
824 * @pinctrl_name: the dev_name() of the pin controller to map to
825 * @gpio_offset: the start offset in the current gpio_chip number space
826 * @pin_offset: the start offset in the pin controller number space
827 * @npins: the number of pins from the offset of each pin space (GPIO and
828 * pin controller) to accumulate in this range
830 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
831 unsigned int gpio_offset, unsigned int pin_offset,
834 struct gpio_pin_range *pin_range;
837 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
839 chip_err(chip, "failed to allocate pin ranges\n");
843 /* Use local offset as range ID */
844 pin_range->range.id = gpio_offset;
845 pin_range->range.gc = chip;
846 pin_range->range.name = chip->label;
847 pin_range->range.base = chip->base + gpio_offset;
848 pin_range->range.pin_base = pin_offset;
849 pin_range->range.npins = npins;
850 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
852 if (IS_ERR(pin_range->pctldev)) {
853 ret = PTR_ERR(pin_range->pctldev);
854 chip_err(chip, "could not create pin range\n");
858 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
859 gpio_offset, gpio_offset + npins - 1,
861 pin_offset, pin_offset + npins - 1);
863 list_add_tail(&pin_range->node, &chip->pin_ranges);
867 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
870 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
871 * @chip: the chip to remove all the mappings for
873 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
875 struct gpio_pin_range *pin_range, *tmp;
877 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
878 list_del(&pin_range->node);
879 pinctrl_remove_gpio_range(pin_range->pctldev,
884 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
886 #endif /* CONFIG_PINCTRL */
888 /* These "optional" allocation calls help prevent drivers from stomping
889 * on each other, and help provide better diagnostics in debugfs.
890 * They're called even less than the "set direction" calls.
892 static int __gpiod_request(struct gpio_desc *desc, const char *label)
894 struct gpio_chip *chip = desc->chip;
898 spin_lock_irqsave(&gpio_lock, flags);
900 /* NOTE: gpio_request() can be called in early boot,
901 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
904 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
905 desc_set_label(desc, label ? : "?");
913 /* chip->request may sleep */
914 spin_unlock_irqrestore(&gpio_lock, flags);
915 status = chip->request(chip, gpio_chip_hwgpio(desc));
916 spin_lock_irqsave(&gpio_lock, flags);
919 desc_set_label(desc, NULL);
920 clear_bit(FLAG_REQUESTED, &desc->flags);
924 if (chip->get_direction) {
925 /* chip->get_direction may sleep */
926 spin_unlock_irqrestore(&gpio_lock, flags);
927 gpiod_get_direction(desc);
928 spin_lock_irqsave(&gpio_lock, flags);
932 /* Clear flags that might have been set by the caller before
933 * requesting the GPIO.
935 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
936 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
937 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
939 spin_unlock_irqrestore(&gpio_lock, flags);
943 int gpiod_request(struct gpio_desc *desc, const char *label)
945 int status = -EPROBE_DEFER;
946 struct gpio_chip *chip;
949 pr_warn("%s: invalid GPIO\n", __func__);
957 if (try_module_get(chip->owner)) {
958 status = __gpiod_request(desc, label);
960 module_put(chip->owner);
965 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
970 static bool __gpiod_free(struct gpio_desc *desc)
974 struct gpio_chip *chip;
978 gpiod_unexport(desc);
980 spin_lock_irqsave(&gpio_lock, flags);
983 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
985 spin_unlock_irqrestore(&gpio_lock, flags);
986 might_sleep_if(chip->can_sleep);
987 chip->free(chip, gpio_chip_hwgpio(desc));
988 spin_lock_irqsave(&gpio_lock, flags);
990 desc_set_label(desc, NULL);
991 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
992 clear_bit(FLAG_REQUESTED, &desc->flags);
993 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
994 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
995 clear_bit(FLAG_IS_HOGGED, &desc->flags);
999 spin_unlock_irqrestore(&gpio_lock, flags);
1003 void gpiod_free(struct gpio_desc *desc)
1005 if (desc && __gpiod_free(desc))
1006 module_put(desc->chip->owner);
1008 WARN_ON(extra_checks);
1012 * gpiochip_is_requested - return string iff signal was requested
1013 * @chip: controller managing the signal
1014 * @offset: of signal within controller's 0..(ngpio - 1) range
1016 * Returns NULL if the GPIO is not currently requested, else a string.
1017 * The string returned is the label passed to gpio_request(); if none has been
1018 * passed it is a meaningless, non-NULL constant.
1020 * This function is for use by GPIO controller drivers. The label can
1021 * help with diagnostics, and knowing that the signal is used as a GPIO
1022 * can help avoid accidentally multiplexing it to another controller.
1024 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1026 struct gpio_desc *desc;
1028 if (offset >= chip->ngpio)
1031 desc = &chip->desc[offset];
1033 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
1037 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1040 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1041 * @desc: GPIO descriptor to request
1042 * @label: label for the GPIO
1044 * Function allows GPIO chip drivers to request and use their own GPIO
1045 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1046 * function will not increase reference count of the GPIO chip module. This
1047 * allows the GPIO chip module to be unloaded as needed (we assume that the
1048 * GPIO chip driver handles freeing the GPIOs it has requested).
1050 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
1053 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
1057 chip_err(chip, "failed to get GPIO descriptor\n");
1061 err = __gpiod_request(desc, label);
1063 return ERR_PTR(err);
1067 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
1070 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1071 * @desc: GPIO descriptor to free
1073 * Function frees the given GPIO requested previously with
1074 * gpiochip_request_own_desc().
1076 void gpiochip_free_own_desc(struct gpio_desc *desc)
1081 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
1083 /* Drivers MUST set GPIO direction before making get/set calls. In
1084 * some cases this is done in early boot, before IRQs are enabled.
1086 * As a rule these aren't called more than once (except for drivers
1087 * using the open-drain emulation idiom) so these are natural places
1088 * to accumulate extra debugging checks. Note that we can't (yet)
1089 * rely on gpio_request() having been called beforehand.
1093 * gpiod_direction_input - set the GPIO direction to input
1094 * @desc: GPIO to set to input
1096 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1097 * be called safely on it.
1099 * Return 0 in case of success, else an error code.
1101 int gpiod_direction_input(struct gpio_desc *desc)
1103 struct gpio_chip *chip;
1104 int status = -EINVAL;
1106 if (!desc || !desc->chip) {
1107 pr_warn("%s: invalid GPIO\n", __func__);
1112 if (!chip->get || !chip->direction_input) {
1114 "%s: missing get() or direction_input() operations\n",
1119 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1121 clear_bit(FLAG_IS_OUT, &desc->flags);
1123 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1127 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1129 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1131 struct gpio_chip *chip;
1132 int status = -EINVAL;
1134 /* GPIOs used for IRQs shall not be set as output */
1135 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1137 "%s: tried to set a GPIO tied to an IRQ as output\n",
1142 /* Open drain pin should not be driven to 1 */
1143 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1144 return gpiod_direction_input(desc);
1146 /* Open source pin should not be driven to 0 */
1147 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1148 return gpiod_direction_input(desc);
1151 if (!chip->set || !chip->direction_output) {
1153 "%s: missing set() or direction_output() operations\n",
1158 status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
1160 set_bit(FLAG_IS_OUT, &desc->flags);
1161 trace_gpio_value(desc_to_gpio(desc), 0, value);
1162 trace_gpio_direction(desc_to_gpio(desc), 0, status);
1167 * gpiod_direction_output_raw - set the GPIO direction to output
1168 * @desc: GPIO to set to output
1169 * @value: initial output value of the GPIO
1171 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1172 * be called safely on it. The initial value of the output must be specified
1173 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1175 * Return 0 in case of success, else an error code.
1177 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1179 if (!desc || !desc->chip) {
1180 pr_warn("%s: invalid GPIO\n", __func__);
1183 return _gpiod_direction_output_raw(desc, value);
1185 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1188 * gpiod_direction_output - set the GPIO direction to output
1189 * @desc: GPIO to set to output
1190 * @value: initial output value of the GPIO
1192 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1193 * be called safely on it. The initial value of the output must be specified
1194 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1197 * Return 0 in case of success, else an error code.
1199 int gpiod_direction_output(struct gpio_desc *desc, int value)
1201 if (!desc || !desc->chip) {
1202 pr_warn("%s: invalid GPIO\n", __func__);
1205 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1207 return _gpiod_direction_output_raw(desc, value);
1209 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1212 * gpiod_set_debounce - sets @debounce time for a @gpio
1213 * @gpio: the gpio to set debounce time
1214 * @debounce: debounce time is microseconds
1216 * returns -ENOTSUPP if the controller does not support setting
1219 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1221 struct gpio_chip *chip;
1223 if (!desc || !desc->chip) {
1224 pr_warn("%s: invalid GPIO\n", __func__);
1229 if (!chip->set || !chip->set_debounce) {
1231 "%s: missing set() or set_debounce() operations\n",
1236 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1238 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1241 * gpiod_is_active_low - test whether a GPIO is active-low or not
1242 * @desc: the gpio descriptor to test
1244 * Returns 1 if the GPIO is active-low, 0 otherwise.
1246 int gpiod_is_active_low(const struct gpio_desc *desc)
1248 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1250 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1252 /* I/O calls are only valid after configuration completed; the relevant
1253 * "is this a valid GPIO" error checks should already have been done.
1255 * "Get" operations are often inlinable as reading a pin value register,
1256 * and masking the relevant bit in that register.
1258 * When "set" operations are inlinable, they involve writing that mask to
1259 * one register to set a low value, or a different register to set it high.
1260 * Otherwise locking is needed, so there may be little value to inlining.
1262 *------------------------------------------------------------------------
1264 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1265 * have requested the GPIO. That can include implicit requesting by
1266 * a direction setting call. Marking a gpio as requested locks its chip
1267 * in memory, guaranteeing that these table lookups need no more locking
1268 * and that gpiochip_remove() will fail.
1270 * REVISIT when debugging, consider adding some instrumentation to ensure
1271 * that the GPIO was actually requested.
1274 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
1276 struct gpio_chip *chip;
1281 offset = gpio_chip_hwgpio(desc);
1282 value = chip->get ? chip->get(chip, offset) : -EIO;
1283 value = value < 0 ? value : !!value;
1284 trace_gpio_value(desc_to_gpio(desc), 1, value);
1289 * gpiod_get_raw_value() - return a gpio's raw value
1290 * @desc: gpio whose value will be returned
1292 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1293 * its ACTIVE_LOW status, or negative errno on failure.
1295 * This function should be called from contexts where we cannot sleep, and will
1296 * complain if the GPIO chip functions potentially sleep.
1298 int gpiod_get_raw_value(const struct gpio_desc *desc)
1302 /* Should be using gpio_get_value_cansleep() */
1303 WARN_ON(desc->chip->can_sleep);
1304 return _gpiod_get_raw_value(desc);
1306 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1309 * gpiod_get_value() - return a gpio's value
1310 * @desc: gpio whose value will be returned
1312 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1313 * account, or negative errno on failure.
1315 * This function should be called from contexts where we cannot sleep, and will
1316 * complain if the GPIO chip functions potentially sleep.
1318 int gpiod_get_value(const struct gpio_desc *desc)
1323 /* Should be using gpio_get_value_cansleep() */
1324 WARN_ON(desc->chip->can_sleep);
1326 value = _gpiod_get_raw_value(desc);
1330 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1335 EXPORT_SYMBOL_GPL(gpiod_get_value);
1338 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1339 * @desc: gpio descriptor whose state need to be set.
1340 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1342 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1345 struct gpio_chip *chip = desc->chip;
1346 int offset = gpio_chip_hwgpio(desc);
1349 err = chip->direction_input(chip, offset);
1351 clear_bit(FLAG_IS_OUT, &desc->flags);
1353 err = chip->direction_output(chip, offset, 0);
1355 set_bit(FLAG_IS_OUT, &desc->flags);
1357 trace_gpio_direction(desc_to_gpio(desc), value, err);
1360 "%s: Error in set_value for open drain err %d\n",
1365 * _gpio_set_open_source_value() - Set the open source gpio's value.
1366 * @desc: gpio descriptor whose state need to be set.
1367 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1369 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1372 struct gpio_chip *chip = desc->chip;
1373 int offset = gpio_chip_hwgpio(desc);
1376 err = chip->direction_output(chip, offset, 1);
1378 set_bit(FLAG_IS_OUT, &desc->flags);
1380 err = chip->direction_input(chip, offset);
1382 clear_bit(FLAG_IS_OUT, &desc->flags);
1384 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1387 "%s: Error in set_value for open source err %d\n",
1391 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1393 struct gpio_chip *chip;
1396 trace_gpio_value(desc_to_gpio(desc), 0, value);
1397 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1398 _gpio_set_open_drain_value(desc, value);
1399 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1400 _gpio_set_open_source_value(desc, value);
1402 chip->set(chip, gpio_chip_hwgpio(desc), value);
1406 * set multiple outputs on the same chip;
1407 * use the chip's set_multiple function if available;
1408 * otherwise set the outputs sequentially;
1409 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1410 * defines which outputs are to be changed
1411 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1412 * defines the values the outputs specified by mask are to be set to
1414 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1415 unsigned long *mask, unsigned long *bits)
1417 if (chip->set_multiple) {
1418 chip->set_multiple(chip, mask, bits);
1421 for (i = 0; i < chip->ngpio; i++) {
1422 if (mask[BIT_WORD(i)] == 0) {
1423 /* no more set bits in this mask word;
1424 * skip ahead to the next word */
1425 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1428 /* set outputs if the corresponding mask bit is set */
1429 if (__test_and_clear_bit(i, mask))
1430 chip->set(chip, i, test_bit(i, bits));
1435 static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
1436 unsigned int array_size,
1437 struct gpio_desc **desc_array,
1442 while (i < array_size) {
1443 struct gpio_chip *chip = desc_array[i]->chip;
1444 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1445 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1449 WARN_ON(chip->can_sleep);
1451 memset(mask, 0, sizeof(mask));
1453 struct gpio_desc *desc = desc_array[i];
1454 int hwgpio = gpio_chip_hwgpio(desc);
1455 int value = value_array[i];
1457 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1459 trace_gpio_value(desc_to_gpio(desc), 0, value);
1461 * collect all normal outputs belonging to the same chip
1462 * open drain and open source outputs are set individually
1464 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1465 _gpio_set_open_drain_value(desc, value);
1466 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1467 _gpio_set_open_source_value(desc, value);
1469 __set_bit(hwgpio, mask);
1471 __set_bit(hwgpio, bits);
1473 __clear_bit(hwgpio, bits);
1477 } while ((i < array_size) && (desc_array[i]->chip == chip));
1478 /* push collected bits to outputs */
1480 gpio_chip_set_multiple(chip, mask, bits);
1485 * gpiod_set_raw_value() - assign a gpio's raw value
1486 * @desc: gpio whose value will be assigned
1487 * @value: value to assign
1489 * Set the raw value of the GPIO, i.e. the value of its physical line without
1490 * regard for its ACTIVE_LOW status.
1492 * This function should be called from contexts where we cannot sleep, and will
1493 * complain if the GPIO chip functions potentially sleep.
1495 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1499 /* Should be using gpio_set_value_cansleep() */
1500 WARN_ON(desc->chip->can_sleep);
1501 _gpiod_set_raw_value(desc, value);
1503 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1506 * gpiod_set_value() - assign a gpio's value
1507 * @desc: gpio whose value will be assigned
1508 * @value: value to assign
1510 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1513 * This function should be called from contexts where we cannot sleep, and will
1514 * complain if the GPIO chip functions potentially sleep.
1516 void gpiod_set_value(struct gpio_desc *desc, int value)
1520 /* Should be using gpio_set_value_cansleep() */
1521 WARN_ON(desc->chip->can_sleep);
1522 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1524 _gpiod_set_raw_value(desc, value);
1526 EXPORT_SYMBOL_GPL(gpiod_set_value);
1529 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1530 * @array_size: number of elements in the descriptor / value arrays
1531 * @desc_array: array of GPIO descriptors whose values will be assigned
1532 * @value_array: array of values to assign
1534 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1535 * without regard for their ACTIVE_LOW status.
1537 * This function should be called from contexts where we cannot sleep, and will
1538 * complain if the GPIO chip functions potentially sleep.
1540 void gpiod_set_raw_array_value(unsigned int array_size,
1541 struct gpio_desc **desc_array, int *value_array)
1545 gpiod_set_array_value_priv(true, false, array_size, desc_array,
1548 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
1551 * gpiod_set_array_value() - assign values to an array of GPIOs
1552 * @array_size: number of elements in the descriptor / value arrays
1553 * @desc_array: array of GPIO descriptors whose values will be assigned
1554 * @value_array: array of values to assign
1556 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1559 * This function should be called from contexts where we cannot sleep, and will
1560 * complain if the GPIO chip functions potentially sleep.
1562 void gpiod_set_array_value(unsigned int array_size,
1563 struct gpio_desc **desc_array, int *value_array)
1567 gpiod_set_array_value_priv(false, false, array_size, desc_array,
1570 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
1573 * gpiod_cansleep() - report whether gpio value access may sleep
1574 * @desc: gpio to check
1577 int gpiod_cansleep(const struct gpio_desc *desc)
1581 return desc->chip->can_sleep;
1583 EXPORT_SYMBOL_GPL(gpiod_cansleep);
1586 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1587 * @desc: gpio whose IRQ will be returned (already requested)
1589 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1592 int gpiod_to_irq(const struct gpio_desc *desc)
1594 struct gpio_chip *chip;
1600 offset = gpio_chip_hwgpio(desc);
1601 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
1603 EXPORT_SYMBOL_GPL(gpiod_to_irq);
1606 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1607 * @chip: the chip the GPIO to lock belongs to
1608 * @offset: the offset of the GPIO to lock as IRQ
1610 * This is used directly by GPIO drivers that want to lock down
1611 * a certain GPIO line to be used for IRQs.
1613 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
1615 if (offset >= chip->ngpio)
1618 if (test_bit(FLAG_IS_OUT, &chip->desc[offset].flags)) {
1620 "%s: tried to flag a GPIO set as output for IRQ\n",
1625 set_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1628 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
1631 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1632 * @chip: the chip the GPIO to lock belongs to
1633 * @offset: the offset of the GPIO to lock as IRQ
1635 * This is used directly by GPIO drivers that want to indicate
1636 * that a certain GPIO is no longer used exclusively for IRQ.
1638 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
1640 if (offset >= chip->ngpio)
1643 clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1645 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
1648 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1649 * @desc: gpio whose value will be returned
1651 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1652 * its ACTIVE_LOW status, or negative errno on failure.
1654 * This function is to be called from contexts that can sleep.
1656 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
1658 might_sleep_if(extra_checks);
1661 return _gpiod_get_raw_value(desc);
1663 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
1666 * gpiod_get_value_cansleep() - return a gpio's value
1667 * @desc: gpio whose value will be returned
1669 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1670 * account, or negative errno on failure.
1672 * This function is to be called from contexts that can sleep.
1674 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
1678 might_sleep_if(extra_checks);
1682 value = _gpiod_get_raw_value(desc);
1686 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1691 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
1694 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
1695 * @desc: gpio whose value will be assigned
1696 * @value: value to assign
1698 * Set the raw value of the GPIO, i.e. the value of its physical line without
1699 * regard for its ACTIVE_LOW status.
1701 * This function is to be called from contexts that can sleep.
1703 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
1705 might_sleep_if(extra_checks);
1708 _gpiod_set_raw_value(desc, value);
1710 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
1713 * gpiod_set_value_cansleep() - assign a gpio's value
1714 * @desc: gpio whose value will be assigned
1715 * @value: value to assign
1717 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1720 * This function is to be called from contexts that can sleep.
1722 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
1724 might_sleep_if(extra_checks);
1728 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1730 _gpiod_set_raw_value(desc, value);
1732 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
1735 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
1736 * @array_size: number of elements in the descriptor / value arrays
1737 * @desc_array: array of GPIO descriptors whose values will be assigned
1738 * @value_array: array of values to assign
1740 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1741 * without regard for their ACTIVE_LOW status.
1743 * This function is to be called from contexts that can sleep.
1745 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
1746 struct gpio_desc **desc_array,
1749 might_sleep_if(extra_checks);
1752 gpiod_set_array_value_priv(true, true, array_size, desc_array,
1755 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
1758 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
1759 * @array_size: number of elements in the descriptor / value arrays
1760 * @desc_array: array of GPIO descriptors whose values will be assigned
1761 * @value_array: array of values to assign
1763 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1766 * This function is to be called from contexts that can sleep.
1768 void gpiod_set_array_value_cansleep(unsigned int array_size,
1769 struct gpio_desc **desc_array,
1772 might_sleep_if(extra_checks);
1775 gpiod_set_array_value_priv(false, true, array_size, desc_array,
1778 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
1781 * gpiod_add_lookup_table() - register GPIO device consumers
1782 * @table: table of consumers to register
1784 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
1786 mutex_lock(&gpio_lookup_lock);
1788 list_add_tail(&table->list, &gpio_lookup_list);
1790 mutex_unlock(&gpio_lookup_lock);
1794 * gpiod_remove_lookup_table() - unregister GPIO device consumers
1795 * @table: table of consumers to unregister
1797 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
1799 mutex_lock(&gpio_lookup_lock);
1801 list_del(&table->list);
1803 mutex_unlock(&gpio_lookup_lock);
1806 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
1808 enum gpio_lookup_flags *flags)
1810 char prop_name[32]; /* 32 is max size of property name */
1811 enum of_gpio_flags of_flags;
1812 struct gpio_desc *desc;
1815 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1817 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
1820 snprintf(prop_name, sizeof(prop_name), "%s",
1823 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
1825 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1832 if (of_flags & OF_GPIO_ACTIVE_LOW)
1833 *flags |= GPIO_ACTIVE_LOW;
1835 if (of_flags & OF_GPIO_SINGLE_ENDED) {
1836 if (of_flags & OF_GPIO_ACTIVE_LOW)
1837 *flags |= GPIO_OPEN_DRAIN;
1839 *flags |= GPIO_OPEN_SOURCE;
1845 static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
1847 enum gpio_lookup_flags *flags)
1849 struct acpi_device *adev = ACPI_COMPANION(dev);
1850 struct acpi_gpio_info info;
1851 struct gpio_desc *desc;
1855 /* Try first from _DSD */
1856 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1857 if (con_id && strcmp(con_id, "gpios")) {
1858 snprintf(propname, sizeof(propname), "%s-%s",
1859 con_id, gpio_suffixes[i]);
1861 snprintf(propname, sizeof(propname), "%s",
1865 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
1866 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1870 /* Then from plain _CRS GPIOs */
1872 if (!acpi_can_fallback_to_crs(adev, con_id))
1873 return ERR_PTR(-ENOENT);
1875 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
1880 if (info.active_low)
1881 *flags |= GPIO_ACTIVE_LOW;
1886 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
1888 const char *dev_id = dev ? dev_name(dev) : NULL;
1889 struct gpiod_lookup_table *table;
1891 mutex_lock(&gpio_lookup_lock);
1893 list_for_each_entry(table, &gpio_lookup_list, list) {
1894 if (table->dev_id && dev_id) {
1896 * Valid strings on both ends, must be identical to have
1899 if (!strcmp(table->dev_id, dev_id))
1903 * One of the pointers is NULL, so both must be to have
1906 if (dev_id == table->dev_id)
1913 mutex_unlock(&gpio_lookup_lock);
1917 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
1919 enum gpio_lookup_flags *flags)
1921 struct gpio_desc *desc = ERR_PTR(-ENOENT);
1922 struct gpiod_lookup_table *table;
1923 struct gpiod_lookup *p;
1925 table = gpiod_find_lookup_table(dev);
1929 for (p = &table->table[0]; p->chip_label; p++) {
1930 struct gpio_chip *chip;
1932 /* idx must always match exactly */
1936 /* If the lookup entry has a con_id, require exact match */
1937 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
1940 chip = find_chip_by_name(p->chip_label);
1943 dev_err(dev, "cannot find GPIO chip %s\n",
1945 return ERR_PTR(-ENODEV);
1948 if (chip->ngpio <= p->chip_hwnum) {
1950 "requested GPIO %d is out of range [0..%d] for chip %s\n",
1951 idx, chip->ngpio, chip->label);
1952 return ERR_PTR(-EINVAL);
1955 desc = gpiochip_get_desc(chip, p->chip_hwnum);
1964 static int dt_gpio_count(struct device *dev, const char *con_id)
1970 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1972 snprintf(propname, sizeof(propname), "%s-%s",
1973 con_id, gpio_suffixes[i]);
1975 snprintf(propname, sizeof(propname), "%s",
1978 ret = of_gpio_named_count(dev->of_node, propname);
1985 static int platform_gpio_count(struct device *dev, const char *con_id)
1987 struct gpiod_lookup_table *table;
1988 struct gpiod_lookup *p;
1989 unsigned int count = 0;
1991 table = gpiod_find_lookup_table(dev);
1995 for (p = &table->table[0]; p->chip_label; p++) {
1996 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
1997 (!con_id && !p->con_id))
2007 * gpiod_count - return the number of GPIOs associated with a device / function
2008 * or -ENOENT if no GPIO has been assigned to the requested function
2009 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2010 * @con_id: function within the GPIO consumer
2012 int gpiod_count(struct device *dev, const char *con_id)
2014 int count = -ENOENT;
2016 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
2017 count = dt_gpio_count(dev, con_id);
2018 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
2019 count = acpi_gpio_count(dev, con_id);
2022 count = platform_gpio_count(dev, con_id);
2026 EXPORT_SYMBOL_GPL(gpiod_count);
2029 * gpiod_get - obtain a GPIO for a given GPIO function
2030 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2031 * @con_id: function within the GPIO consumer
2032 * @flags: optional GPIO initialization flags
2034 * Return the GPIO descriptor corresponding to the function con_id of device
2035 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2036 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2038 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
2039 enum gpiod_flags flags)
2041 return gpiod_get_index(dev, con_id, 0, flags);
2043 EXPORT_SYMBOL_GPL(gpiod_get);
2046 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2047 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2048 * @con_id: function within the GPIO consumer
2049 * @flags: optional GPIO initialization flags
2051 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2052 * the requested function it will return NULL. This is convenient for drivers
2053 * that need to handle optional GPIOs.
2055 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
2057 enum gpiod_flags flags)
2059 return gpiod_get_index_optional(dev, con_id, 0, flags);
2061 EXPORT_SYMBOL_GPL(gpiod_get_optional);
2064 * gpiod_parse_flags - helper function to parse GPIO lookup flags
2065 * @desc: gpio to be setup
2066 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2069 * Set the GPIO descriptor flags based on the given GPIO lookup flags.
2071 static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags)
2073 if (lflags & GPIO_ACTIVE_LOW)
2074 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2075 if (lflags & GPIO_OPEN_DRAIN)
2076 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2077 if (lflags & GPIO_OPEN_SOURCE)
2078 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2082 * gpiod_configure_flags - helper function to configure a given GPIO
2083 * @desc: gpio whose value will be assigned
2084 * @con_id: function within the GPIO consumer
2085 * @dflags: gpiod_flags - optional GPIO initialization flags
2087 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2088 * requested function and/or index, or another IS_ERR() code if an error
2089 * occurred while trying to acquire the GPIO.
2091 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
2092 enum gpiod_flags dflags)
2096 /* No particular flag request, return here... */
2097 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
2098 pr_debug("no flags found for %s\n", con_id);
2103 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
2104 status = gpiod_direction_output(desc,
2105 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
2107 status = gpiod_direction_input(desc);
2113 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2114 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2115 * @con_id: function within the GPIO consumer
2116 * @idx: index of the GPIO to obtain in the consumer
2117 * @flags: optional GPIO initialization flags
2119 * This variant of gpiod_get() allows to access GPIOs other than the first
2120 * defined one for functions that define several GPIOs.
2122 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2123 * requested function and/or index, or another IS_ERR() code if an error
2124 * occurred while trying to acquire the GPIO.
2126 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2129 enum gpiod_flags flags)
2131 struct gpio_desc *desc = NULL;
2133 enum gpio_lookup_flags lookupflags = 0;
2135 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2138 /* Using device tree? */
2139 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
2140 dev_dbg(dev, "using device tree for GPIO lookup\n");
2141 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
2142 } else if (ACPI_COMPANION(dev)) {
2143 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2144 desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
2149 * Either we are not using DT or ACPI, or their lookup did not return
2150 * a result. In that case, use platform lookup as a fallback.
2152 if (!desc || desc == ERR_PTR(-ENOENT)) {
2153 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2154 desc = gpiod_find(dev, con_id, idx, &lookupflags);
2158 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2162 gpiod_parse_flags(desc, lookupflags);
2164 status = gpiod_request(desc, con_id);
2166 return ERR_PTR(status);
2168 status = gpiod_configure_flags(desc, con_id, flags);
2170 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2172 return ERR_PTR(status);
2177 EXPORT_SYMBOL_GPL(gpiod_get_index);
2180 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2181 * @fwnode: handle of the firmware node
2182 * @propname: name of the firmware property representing the GPIO
2184 * This function can be used for drivers that get their configuration
2187 * Function properly finds the corresponding GPIO using whatever is the
2188 * underlying firmware interface and then makes sure that the GPIO
2189 * descriptor is requested before it is returned to the caller.
2191 * In case of error an ERR_PTR() is returned.
2193 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2194 const char *propname)
2196 struct gpio_desc *desc = ERR_PTR(-ENODEV);
2197 bool active_low = false;
2198 bool single_ended = false;
2202 return ERR_PTR(-EINVAL);
2204 if (is_of_node(fwnode)) {
2205 enum of_gpio_flags flags;
2207 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2209 if (!IS_ERR(desc)) {
2210 active_low = flags & OF_GPIO_ACTIVE_LOW;
2211 single_ended = flags & OF_GPIO_SINGLE_ENDED;
2213 } else if (is_acpi_node(fwnode)) {
2214 struct acpi_gpio_info info;
2216 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
2218 active_low = info.active_low;
2225 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2229 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2231 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2234 ret = gpiod_request(desc, NULL);
2236 return ERR_PTR(ret);
2240 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2243 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2245 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2246 * @con_id: function within the GPIO consumer
2247 * @index: index of the GPIO to obtain in the consumer
2248 * @flags: optional GPIO initialization flags
2250 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2251 * specified index was assigned to the requested function it will return NULL.
2252 * This is convenient for drivers that need to handle optional GPIOs.
2254 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2257 enum gpiod_flags flags)
2259 struct gpio_desc *desc;
2261 desc = gpiod_get_index(dev, con_id, index, flags);
2263 if (PTR_ERR(desc) == -ENOENT)
2269 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2272 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2273 * @desc: gpio whose value will be assigned
2274 * @name: gpio line name
2275 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2277 * @dflags: gpiod_flags - optional GPIO initialization flags
2279 int gpiod_hog(struct gpio_desc *desc, const char *name,
2280 unsigned long lflags, enum gpiod_flags dflags)
2282 struct gpio_chip *chip;
2283 struct gpio_desc *local_desc;
2287 chip = gpiod_to_chip(desc);
2288 hwnum = gpio_chip_hwgpio(desc);
2290 gpiod_parse_flags(desc, lflags);
2292 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2293 if (IS_ERR(local_desc)) {
2294 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2295 name, chip->label, hwnum);
2296 return PTR_ERR(local_desc);
2299 status = gpiod_configure_flags(desc, name, dflags);
2301 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2302 name, chip->label, hwnum);
2303 gpiochip_free_own_desc(desc);
2307 /* Mark GPIO as hogged so it can be identified and removed later */
2308 set_bit(FLAG_IS_HOGGED, &desc->flags);
2310 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2311 desc_to_gpio(desc), name,
2312 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2313 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2314 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2320 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2321 * @chip: gpio chip to act on
2323 * This is only used by of_gpiochip_remove to free hogged gpios
2325 static void gpiochip_free_hogs(struct gpio_chip *chip)
2329 for (id = 0; id < chip->ngpio; id++) {
2330 if (test_bit(FLAG_IS_HOGGED, &chip->desc[id].flags))
2331 gpiochip_free_own_desc(&chip->desc[id]);
2336 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2337 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2338 * @con_id: function within the GPIO consumer
2339 * @flags: optional GPIO initialization flags
2341 * This function acquires all the GPIOs defined under a given function.
2343 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2344 * no GPIO has been assigned to the requested function, or another IS_ERR()
2345 * code if an error occurred while trying to acquire the GPIOs.
2347 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2349 enum gpiod_flags flags)
2351 struct gpio_desc *desc;
2352 struct gpio_descs *descs;
2355 count = gpiod_count(dev, con_id);
2357 return ERR_PTR(count);
2359 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2362 return ERR_PTR(-ENOMEM);
2364 for (descs->ndescs = 0; descs->ndescs < count; ) {
2365 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2367 gpiod_put_array(descs);
2368 return ERR_CAST(desc);
2370 descs->desc[descs->ndescs] = desc;
2375 EXPORT_SYMBOL_GPL(gpiod_get_array);
2378 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2380 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2381 * @con_id: function within the GPIO consumer
2382 * @flags: optional GPIO initialization flags
2384 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2385 * assigned to the requested function it will return NULL.
2387 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2389 enum gpiod_flags flags)
2391 struct gpio_descs *descs;
2393 descs = gpiod_get_array(dev, con_id, flags);
2394 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2399 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2402 * gpiod_put - dispose of a GPIO descriptor
2403 * @desc: GPIO descriptor to dispose of
2405 * No descriptor can be used after gpiod_put() has been called on it.
2407 void gpiod_put(struct gpio_desc *desc)
2411 EXPORT_SYMBOL_GPL(gpiod_put);
2414 * gpiod_put_array - dispose of multiple GPIO descriptors
2415 * @descs: struct gpio_descs containing an array of descriptors
2417 void gpiod_put_array(struct gpio_descs *descs)
2421 for (i = 0; i < descs->ndescs; i++)
2422 gpiod_put(descs->desc[i]);
2426 EXPORT_SYMBOL_GPL(gpiod_put_array);
2428 #ifdef CONFIG_DEBUG_FS
2430 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2433 unsigned gpio = chip->base;
2434 struct gpio_desc *gdesc = &chip->desc[0];
2438 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2439 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
2441 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
2447 gpiod_get_direction(gdesc);
2448 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2449 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2450 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2451 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
2452 is_out ? "out" : "in ",
2454 ? (chip->get(chip, i) ? "hi" : "lo")
2456 is_irq ? "IRQ" : " ");
2457 seq_printf(s, "\n");
2461 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2463 unsigned long flags;
2464 struct gpio_chip *chip = NULL;
2465 loff_t index = *pos;
2469 spin_lock_irqsave(&gpio_lock, flags);
2470 list_for_each_entry(chip, &gpio_chips, list)
2472 spin_unlock_irqrestore(&gpio_lock, flags);
2475 spin_unlock_irqrestore(&gpio_lock, flags);
2480 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2482 unsigned long flags;
2483 struct gpio_chip *chip = v;
2486 spin_lock_irqsave(&gpio_lock, flags);
2487 if (list_is_last(&chip->list, &gpio_chips))
2490 ret = list_entry(chip->list.next, struct gpio_chip, list);
2491 spin_unlock_irqrestore(&gpio_lock, flags);
2499 static void gpiolib_seq_stop(struct seq_file *s, void *v)
2503 static int gpiolib_seq_show(struct seq_file *s, void *v)
2505 struct gpio_chip *chip = v;
2508 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2509 chip->base, chip->base + chip->ngpio - 1);
2512 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2515 seq_printf(s, ", %s", chip->label);
2516 if (chip->can_sleep)
2517 seq_printf(s, ", can sleep");
2518 seq_printf(s, ":\n");
2521 chip->dbg_show(s, chip);
2523 gpiolib_dbg_show(s, chip);
2528 static const struct seq_operations gpiolib_seq_ops = {
2529 .start = gpiolib_seq_start,
2530 .next = gpiolib_seq_next,
2531 .stop = gpiolib_seq_stop,
2532 .show = gpiolib_seq_show,
2535 static int gpiolib_open(struct inode *inode, struct file *file)
2537 return seq_open(file, &gpiolib_seq_ops);
2540 static const struct file_operations gpiolib_operations = {
2541 .owner = THIS_MODULE,
2542 .open = gpiolib_open,
2544 .llseek = seq_lseek,
2545 .release = seq_release,
2548 static int __init gpiolib_debugfs_init(void)
2550 /* /sys/kernel/debug/gpio */
2551 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2552 NULL, NULL, &gpiolib_operations);
2555 subsys_initcall(gpiolib_debugfs_init);
2557 #endif /* DEBUG_FS */