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);
167 * Open drain emulation using input mode may incorrectly report
168 * input here, fix that up.
170 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
171 test_bit(FLAG_IS_OUT, &desc->flags))
174 if (!chip->get_direction)
177 status = chip->get_direction(chip, offset);
179 /* GPIOF_DIR_IN, or other positive */
181 clear_bit(FLAG_IS_OUT, &desc->flags);
185 set_bit(FLAG_IS_OUT, &desc->flags);
189 EXPORT_SYMBOL_GPL(gpiod_get_direction);
192 * Add a new chip to the global chips list, keeping the list of chips sorted
195 * Return -EBUSY if the new chip overlaps with some other chip's integer
198 static int gpiochip_add_to_list(struct gpio_chip *chip)
200 struct list_head *pos;
201 struct gpio_chip *_chip;
204 /* find where to insert our chip */
205 list_for_each(pos, &gpio_chips) {
206 _chip = list_entry(pos, struct gpio_chip, list);
207 /* shall we insert before _chip? */
208 if (_chip->base >= chip->base + chip->ngpio)
212 /* are we stepping on the chip right before? */
213 if (pos != &gpio_chips && pos->prev != &gpio_chips) {
214 _chip = list_entry(pos->prev, struct gpio_chip, list);
215 if (_chip->base + _chip->ngpio > chip->base) {
217 "GPIO integer space overlap, cannot add chip\n");
223 list_add_tail(&chip->list, pos);
229 * Convert a GPIO name to its descriptor
231 static struct gpio_desc *gpio_name_to_desc(const char * const name)
233 struct gpio_chip *chip;
236 spin_lock_irqsave(&gpio_lock, flags);
238 list_for_each_entry(chip, &gpio_chips, list) {
241 for (i = 0; i != chip->ngpio; ++i) {
242 struct gpio_desc *gpio = &chip->desc[i];
244 if (!gpio->name || !name)
247 if (!strcmp(gpio->name, name)) {
248 spin_unlock_irqrestore(&gpio_lock, flags);
254 spin_unlock_irqrestore(&gpio_lock, flags);
260 * Takes the names from gc->names and checks if they are all unique. If they
261 * are, they are assigned to their gpio descriptors.
263 * Returns -EEXIST if one of the names is already used for a different GPIO.
265 static int gpiochip_set_desc_names(struct gpio_chip *gc)
272 /* First check all names if they are unique */
273 for (i = 0; i != gc->ngpio; ++i) {
274 struct gpio_desc *gpio;
276 gpio = gpio_name_to_desc(gc->names[i]);
278 dev_warn(gc->dev, "Detected name collision for "
283 /* Then add all names to the GPIO descriptors */
284 for (i = 0; i != gc->ngpio; ++i)
285 gc->desc[i].name = gc->names[i];
291 * gpiochip_add() - register a gpio_chip
292 * @chip: the chip to register, with chip->base initialized
293 * Context: potentially before irqs will work
295 * Returns a negative errno if the chip can't be registered, such as
296 * because the chip->base is invalid or already associated with a
297 * different chip. Otherwise it returns zero as a success code.
299 * When gpiochip_add() is called very early during boot, so that GPIOs
300 * can be freely used, the chip->dev device must be registered before
301 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
302 * for GPIOs will fail rudely.
304 * If chip->base is negative, this requests dynamic assignment of
305 * a range of valid GPIOs.
307 int gpiochip_add(struct gpio_chip *chip)
312 int base = chip->base;
313 struct gpio_desc *descs;
315 descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL);
319 spin_lock_irqsave(&gpio_lock, flags);
322 base = gpiochip_find_base(chip->ngpio);
325 spin_unlock_irqrestore(&gpio_lock, flags);
331 status = gpiochip_add_to_list(chip);
333 spin_unlock_irqrestore(&gpio_lock, flags);
337 for (id = 0; id < chip->ngpio; id++) {
338 struct gpio_desc *desc = &descs[id];
342 /* REVISIT: most hardware initializes GPIOs as inputs (often
343 * with pullups enabled) so power usage is minimized. Linux
344 * code should set the gpio direction first thing; but until
345 * it does, and in case chip->get_direction is not set, we may
346 * expose the wrong direction in sysfs.
348 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
353 spin_unlock_irqrestore(&gpio_lock, flags);
355 #ifdef CONFIG_PINCTRL
356 INIT_LIST_HEAD(&chip->pin_ranges);
359 if (!chip->owner && chip->dev && chip->dev->driver)
360 chip->owner = chip->dev->driver->owner;
362 status = gpiochip_set_desc_names(chip);
364 goto err_remove_from_list;
366 status = of_gpiochip_add(chip);
368 goto err_remove_chip;
370 acpi_gpiochip_add(chip);
372 status = gpiochip_sysfs_register(chip);
374 goto err_remove_chip;
376 pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
377 chip->base, chip->base + chip->ngpio - 1,
378 chip->label ? : "generic");
383 acpi_gpiochip_remove(chip);
384 gpiochip_free_hogs(chip);
385 of_gpiochip_remove(chip);
386 err_remove_from_list:
387 spin_lock_irqsave(&gpio_lock, flags);
388 list_del(&chip->list);
389 spin_unlock_irqrestore(&gpio_lock, flags);
394 /* failures here can mean systems won't boot... */
395 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
396 chip->base, chip->base + chip->ngpio - 1,
397 chip->label ? : "generic");
400 EXPORT_SYMBOL_GPL(gpiochip_add);
403 * gpiochip_remove() - unregister a gpio_chip
404 * @chip: the chip to unregister
406 * A gpio_chip with any GPIOs still requested may not be removed.
408 void gpiochip_remove(struct gpio_chip *chip)
410 struct gpio_desc *desc;
413 bool requested = false;
415 gpiochip_sysfs_unregister(chip);
417 gpiochip_irqchip_remove(chip);
419 acpi_gpiochip_remove(chip);
420 gpiochip_remove_pin_ranges(chip);
421 gpiochip_free_hogs(chip);
422 of_gpiochip_remove(chip);
424 spin_lock_irqsave(&gpio_lock, flags);
425 for (id = 0; id < chip->ngpio; id++) {
426 desc = &chip->desc[id];
428 if (test_bit(FLAG_REQUESTED, &desc->flags))
431 list_del(&chip->list);
432 spin_unlock_irqrestore(&gpio_lock, flags);
435 dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
440 EXPORT_SYMBOL_GPL(gpiochip_remove);
443 * gpiochip_find() - iterator for locating a specific gpio_chip
444 * @data: data to pass to match function
445 * @callback: Callback function to check gpio_chip
447 * Similar to bus_find_device. It returns a reference to a gpio_chip as
448 * determined by a user supplied @match callback. The callback should return
449 * 0 if the device doesn't match and non-zero if it does. If the callback is
450 * non-zero, this function will return to the caller and not iterate over any
453 struct gpio_chip *gpiochip_find(void *data,
454 int (*match)(struct gpio_chip *chip,
457 struct gpio_chip *chip;
460 spin_lock_irqsave(&gpio_lock, flags);
461 list_for_each_entry(chip, &gpio_chips, list)
462 if (match(chip, data))
466 if (&chip->list == &gpio_chips)
468 spin_unlock_irqrestore(&gpio_lock, flags);
472 EXPORT_SYMBOL_GPL(gpiochip_find);
474 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
476 const char *name = data;
478 return !strcmp(chip->label, name);
481 static struct gpio_chip *find_chip_by_name(const char *name)
483 return gpiochip_find((void *)name, gpiochip_match_name);
486 #ifdef CONFIG_GPIOLIB_IRQCHIP
489 * The following is irqchip helper code for gpiochips.
493 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
494 * @gpiochip: the gpiochip to set the irqchip chain to
495 * @irqchip: the irqchip to chain to the gpiochip
496 * @parent_irq: the irq number corresponding to the parent IRQ for this
498 * @parent_handler: the parent interrupt handler for the accumulated IRQ
499 * coming out of the gpiochip. If the interrupt is nested rather than
500 * cascaded, pass NULL in this handler argument
502 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
503 struct irq_chip *irqchip,
505 irq_flow_handler_t parent_handler)
509 if (!gpiochip->irqdomain) {
510 chip_err(gpiochip, "called %s before setting up irqchip\n",
515 if (parent_handler) {
516 if (gpiochip->can_sleep) {
518 "you cannot have chained interrupts on a "
519 "chip that may sleep\n");
523 * The parent irqchip is already using the chip_data for this
524 * irqchip, so our callbacks simply use the handler_data.
526 irq_set_chained_handler_and_data(parent_irq, parent_handler,
529 gpiochip->irq_parent = parent_irq;
532 /* Set the parent IRQ for all affected IRQs */
533 for (offset = 0; offset < gpiochip->ngpio; offset++)
534 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
537 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
540 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
541 * @d: the irqdomain used by this irqchip
542 * @irq: the global irq number used by this GPIO irqchip irq
543 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
545 * This function will set up the mapping for a certain IRQ line on a
546 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
547 * stored inside the gpiochip.
549 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
550 irq_hw_number_t hwirq)
552 struct gpio_chip *chip = d->host_data;
554 irq_set_chip_data(irq, chip);
556 * This lock class tells lockdep that GPIO irqs are in a different
557 * category than their parents, so it won't report false recursion.
559 irq_set_lockdep_class(irq, chip->lock_key);
560 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
561 /* Chips that can sleep need nested thread handlers */
562 if (chip->can_sleep && !chip->irq_not_threaded)
563 irq_set_nested_thread(irq, 1);
564 irq_set_noprobe(irq);
567 * No set-up of the hardware will happen if IRQ_TYPE_NONE
568 * is passed as default type.
570 if (chip->irq_default_type != IRQ_TYPE_NONE)
571 irq_set_irq_type(irq, chip->irq_default_type);
576 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
578 struct gpio_chip *chip = d->host_data;
581 irq_set_nested_thread(irq, 0);
582 irq_set_chip_and_handler(irq, NULL, NULL);
583 irq_set_chip_data(irq, NULL);
586 static const struct irq_domain_ops gpiochip_domain_ops = {
587 .map = gpiochip_irq_map,
588 .unmap = gpiochip_irq_unmap,
589 /* Virtually all GPIO irqchips are twocell:ed */
590 .xlate = irq_domain_xlate_twocell,
593 static int gpiochip_irq_reqres(struct irq_data *d)
595 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
597 if (!try_module_get(chip->owner))
600 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
602 "unable to lock HW IRQ %lu for IRQ\n",
604 module_put(chip->owner);
610 static void gpiochip_irq_relres(struct irq_data *d)
612 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
614 gpiochip_unlock_as_irq(chip, d->hwirq);
615 module_put(chip->owner);
618 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
620 return irq_find_mapping(chip->irqdomain, offset);
624 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
625 * @gpiochip: the gpiochip to remove the irqchip from
627 * This is called only from gpiochip_remove()
629 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
633 acpi_gpiochip_free_interrupts(gpiochip);
635 if (gpiochip->irq_parent) {
636 irq_set_chained_handler(gpiochip->irq_parent, NULL);
637 irq_set_handler_data(gpiochip->irq_parent, NULL);
640 /* Remove all IRQ mappings and delete the domain */
641 if (gpiochip->irqdomain) {
642 for (offset = 0; offset < gpiochip->ngpio; offset++)
644 irq_find_mapping(gpiochip->irqdomain, offset));
645 irq_domain_remove(gpiochip->irqdomain);
648 if (gpiochip->irqchip) {
649 gpiochip->irqchip->irq_request_resources = NULL;
650 gpiochip->irqchip->irq_release_resources = NULL;
651 gpiochip->irqchip = NULL;
656 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
657 * @gpiochip: the gpiochip to add the irqchip to
658 * @irqchip: the irqchip to add to the gpiochip
659 * @first_irq: if not dynamically assigned, the base (first) IRQ to
660 * allocate gpiochip irqs from
661 * @handler: the irq handler to use (often a predefined irq core function)
662 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
663 * to have the core avoid setting up any default type in the hardware.
664 * @lock_key: lockdep class
666 * This function closely associates a certain irqchip with a certain
667 * gpiochip, providing an irq domain to translate the local IRQs to
668 * global irqs in the gpiolib core, and making sure that the gpiochip
669 * is passed as chip data to all related functions. Driver callbacks
670 * need to use container_of() to get their local state containers back
671 * from the gpiochip passed as chip data. An irqdomain will be stored
672 * in the gpiochip that shall be used by the driver to handle IRQ number
673 * translation. The gpiochip will need to be initialized and registered
674 * before calling this function.
676 * This function will handle two cell:ed simple IRQs and assumes all
677 * the pins on the gpiochip can generate a unique IRQ. Everything else
678 * need to be open coded.
680 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
681 struct irq_chip *irqchip,
682 unsigned int first_irq,
683 irq_flow_handler_t handler,
685 struct lock_class_key *lock_key)
687 struct device_node *of_node;
689 unsigned irq_base = 0;
691 if (!gpiochip || !irqchip)
694 if (!gpiochip->dev) {
695 pr_err("missing gpiochip .dev parent pointer\n");
698 of_node = gpiochip->dev->of_node;
699 #ifdef CONFIG_OF_GPIO
701 * If the gpiochip has an assigned OF node this takes precedence
702 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
704 if (gpiochip->of_node)
705 of_node = gpiochip->of_node;
707 gpiochip->irqchip = irqchip;
708 gpiochip->irq_handler = handler;
709 gpiochip->irq_default_type = type;
710 gpiochip->to_irq = gpiochip_to_irq;
711 gpiochip->lock_key = lock_key;
712 gpiochip->irqdomain = irq_domain_add_simple(of_node,
713 gpiochip->ngpio, first_irq,
714 &gpiochip_domain_ops, gpiochip);
715 if (!gpiochip->irqdomain) {
716 gpiochip->irqchip = NULL;
721 * It is possible for a driver to override this, but only if the
722 * alternative functions are both implemented.
724 if (!irqchip->irq_request_resources &&
725 !irqchip->irq_release_resources) {
726 irqchip->irq_request_resources = gpiochip_irq_reqres;
727 irqchip->irq_release_resources = gpiochip_irq_relres;
731 * Prepare the mapping since the irqchip shall be orthogonal to
732 * any gpiochip calls. If the first_irq was zero, this is
733 * necessary to allocate descriptors for all IRQs.
735 for (offset = 0; offset < gpiochip->ngpio; offset++) {
736 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
739 * Store the base into the gpiochip to be used when
740 * unmapping the irqs.
742 gpiochip->irq_base = irq_base;
745 acpi_gpiochip_request_interrupts(gpiochip);
749 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
751 #else /* CONFIG_GPIOLIB_IRQCHIP */
753 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
755 #endif /* CONFIG_GPIOLIB_IRQCHIP */
758 * gpiochip_generic_request() - request the gpio function for a pin
759 * @chip: the gpiochip owning the GPIO
760 * @offset: the offset of the GPIO to request for GPIO function
762 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
764 return pinctrl_request_gpio(chip->base + offset);
766 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
769 * gpiochip_generic_free() - free the gpio function from a pin
770 * @chip: the gpiochip to request the gpio function for
771 * @offset: the offset of the GPIO to free from GPIO function
773 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
775 pinctrl_free_gpio(chip->base + offset);
777 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
779 #ifdef CONFIG_PINCTRL
782 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
783 * @chip: the gpiochip to add the range for
784 * @pctldev: the pin controller to map to
785 * @gpio_offset: the start offset in the current gpio_chip number space
786 * @pin_group: name of the pin group inside the pin controller
788 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
789 struct pinctrl_dev *pctldev,
790 unsigned int gpio_offset, const char *pin_group)
792 struct gpio_pin_range *pin_range;
795 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
797 chip_err(chip, "failed to allocate pin ranges\n");
801 /* Use local offset as range ID */
802 pin_range->range.id = gpio_offset;
803 pin_range->range.gc = chip;
804 pin_range->range.name = chip->label;
805 pin_range->range.base = chip->base + gpio_offset;
806 pin_range->pctldev = pctldev;
808 ret = pinctrl_get_group_pins(pctldev, pin_group,
809 &pin_range->range.pins,
810 &pin_range->range.npins);
816 pinctrl_add_gpio_range(pctldev, &pin_range->range);
818 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
819 gpio_offset, gpio_offset + pin_range->range.npins - 1,
820 pinctrl_dev_get_devname(pctldev), pin_group);
822 list_add_tail(&pin_range->node, &chip->pin_ranges);
826 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
829 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
830 * @chip: the gpiochip to add the range for
831 * @pinctrl_name: the dev_name() of the pin controller to map to
832 * @gpio_offset: the start offset in the current gpio_chip number space
833 * @pin_offset: the start offset in the pin controller number space
834 * @npins: the number of pins from the offset of each pin space (GPIO and
835 * pin controller) to accumulate in this range
837 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
838 unsigned int gpio_offset, unsigned int pin_offset,
841 struct gpio_pin_range *pin_range;
844 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
846 chip_err(chip, "failed to allocate pin ranges\n");
850 /* Use local offset as range ID */
851 pin_range->range.id = gpio_offset;
852 pin_range->range.gc = chip;
853 pin_range->range.name = chip->label;
854 pin_range->range.base = chip->base + gpio_offset;
855 pin_range->range.pin_base = pin_offset;
856 pin_range->range.npins = npins;
857 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
859 if (IS_ERR(pin_range->pctldev)) {
860 ret = PTR_ERR(pin_range->pctldev);
861 chip_err(chip, "could not create pin range\n");
865 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
866 gpio_offset, gpio_offset + npins - 1,
868 pin_offset, pin_offset + npins - 1);
870 list_add_tail(&pin_range->node, &chip->pin_ranges);
874 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
877 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
878 * @chip: the chip to remove all the mappings for
880 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
882 struct gpio_pin_range *pin_range, *tmp;
884 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
885 list_del(&pin_range->node);
886 pinctrl_remove_gpio_range(pin_range->pctldev,
891 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
893 #endif /* CONFIG_PINCTRL */
895 /* These "optional" allocation calls help prevent drivers from stomping
896 * on each other, and help provide better diagnostics in debugfs.
897 * They're called even less than the "set direction" calls.
899 static int __gpiod_request(struct gpio_desc *desc, const char *label)
901 struct gpio_chip *chip = desc->chip;
905 spin_lock_irqsave(&gpio_lock, flags);
907 /* NOTE: gpio_request() can be called in early boot,
908 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
911 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
912 desc_set_label(desc, label ? : "?");
920 /* chip->request may sleep */
921 spin_unlock_irqrestore(&gpio_lock, flags);
922 status = chip->request(chip, gpio_chip_hwgpio(desc));
923 spin_lock_irqsave(&gpio_lock, flags);
926 desc_set_label(desc, NULL);
927 clear_bit(FLAG_REQUESTED, &desc->flags);
931 if (chip->get_direction) {
932 /* chip->get_direction may sleep */
933 spin_unlock_irqrestore(&gpio_lock, flags);
934 gpiod_get_direction(desc);
935 spin_lock_irqsave(&gpio_lock, flags);
938 spin_unlock_irqrestore(&gpio_lock, flags);
942 int gpiod_request(struct gpio_desc *desc, const char *label)
944 int status = -EPROBE_DEFER;
945 struct gpio_chip *chip;
948 pr_warn("%s: invalid GPIO\n", __func__);
956 if (try_module_get(chip->owner)) {
957 status = __gpiod_request(desc, label);
959 module_put(chip->owner);
964 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
969 static bool __gpiod_free(struct gpio_desc *desc)
973 struct gpio_chip *chip;
977 gpiod_unexport(desc);
979 spin_lock_irqsave(&gpio_lock, flags);
982 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
984 spin_unlock_irqrestore(&gpio_lock, flags);
985 might_sleep_if(chip->can_sleep);
986 chip->free(chip, gpio_chip_hwgpio(desc));
987 spin_lock_irqsave(&gpio_lock, flags);
989 desc_set_label(desc, NULL);
990 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
991 clear_bit(FLAG_REQUESTED, &desc->flags);
992 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
993 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
994 clear_bit(FLAG_IS_HOGGED, &desc->flags);
998 spin_unlock_irqrestore(&gpio_lock, flags);
1002 void gpiod_free(struct gpio_desc *desc)
1004 if (desc && __gpiod_free(desc))
1005 module_put(desc->chip->owner);
1007 WARN_ON(extra_checks);
1011 * gpiochip_is_requested - return string iff signal was requested
1012 * @chip: controller managing the signal
1013 * @offset: of signal within controller's 0..(ngpio - 1) range
1015 * Returns NULL if the GPIO is not currently requested, else a string.
1016 * The string returned is the label passed to gpio_request(); if none has been
1017 * passed it is a meaningless, non-NULL constant.
1019 * This function is for use by GPIO controller drivers. The label can
1020 * help with diagnostics, and knowing that the signal is used as a GPIO
1021 * can help avoid accidentally multiplexing it to another controller.
1023 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1025 struct gpio_desc *desc;
1027 if (offset >= chip->ngpio)
1030 desc = &chip->desc[offset];
1032 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
1036 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1039 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1040 * @desc: GPIO descriptor to request
1041 * @label: label for the GPIO
1043 * Function allows GPIO chip drivers to request and use their own GPIO
1044 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1045 * function will not increase reference count of the GPIO chip module. This
1046 * allows the GPIO chip module to be unloaded as needed (we assume that the
1047 * GPIO chip driver handles freeing the GPIOs it has requested).
1049 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
1052 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
1056 chip_err(chip, "failed to get GPIO descriptor\n");
1060 err = __gpiod_request(desc, label);
1062 return ERR_PTR(err);
1066 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
1069 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1070 * @desc: GPIO descriptor to free
1072 * Function frees the given GPIO requested previously with
1073 * gpiochip_request_own_desc().
1075 void gpiochip_free_own_desc(struct gpio_desc *desc)
1080 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
1082 /* Drivers MUST set GPIO direction before making get/set calls. In
1083 * some cases this is done in early boot, before IRQs are enabled.
1085 * As a rule these aren't called more than once (except for drivers
1086 * using the open-drain emulation idiom) so these are natural places
1087 * to accumulate extra debugging checks. Note that we can't (yet)
1088 * rely on gpio_request() having been called beforehand.
1092 * gpiod_direction_input - set the GPIO direction to input
1093 * @desc: GPIO to set to input
1095 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1096 * be called safely on it.
1098 * Return 0 in case of success, else an error code.
1100 int gpiod_direction_input(struct gpio_desc *desc)
1102 struct gpio_chip *chip;
1103 int status = -EINVAL;
1105 if (!desc || !desc->chip) {
1106 pr_warn("%s: invalid GPIO\n", __func__);
1111 if (!chip->get || !chip->direction_input) {
1113 "%s: missing get() or direction_input() operations\n",
1118 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1120 clear_bit(FLAG_IS_OUT, &desc->flags);
1122 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1126 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1128 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1130 struct gpio_chip *chip;
1131 int status = -EINVAL;
1133 /* GPIOs used for IRQs shall not be set as output */
1134 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1136 "%s: tried to set a GPIO tied to an IRQ as output\n",
1141 /* Open drain pin should not be driven to 1 */
1142 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1143 return gpiod_direction_input(desc);
1145 /* Open source pin should not be driven to 0 */
1146 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1147 return gpiod_direction_input(desc);
1150 if (!chip->set || !chip->direction_output) {
1152 "%s: missing set() or direction_output() operations\n",
1157 status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
1159 set_bit(FLAG_IS_OUT, &desc->flags);
1160 trace_gpio_value(desc_to_gpio(desc), 0, value);
1161 trace_gpio_direction(desc_to_gpio(desc), 0, status);
1166 * gpiod_direction_output_raw - set the GPIO direction to output
1167 * @desc: GPIO to set to output
1168 * @value: initial output value of the GPIO
1170 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1171 * be called safely on it. The initial value of the output must be specified
1172 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1174 * Return 0 in case of success, else an error code.
1176 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1178 if (!desc || !desc->chip) {
1179 pr_warn("%s: invalid GPIO\n", __func__);
1182 return _gpiod_direction_output_raw(desc, value);
1184 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1187 * gpiod_direction_output - set the GPIO direction to output
1188 * @desc: GPIO to set to output
1189 * @value: initial output value of the GPIO
1191 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1192 * be called safely on it. The initial value of the output must be specified
1193 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1196 * Return 0 in case of success, else an error code.
1198 int gpiod_direction_output(struct gpio_desc *desc, int value)
1200 if (!desc || !desc->chip) {
1201 pr_warn("%s: invalid GPIO\n", __func__);
1204 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1206 return _gpiod_direction_output_raw(desc, value);
1208 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1211 * gpiod_set_debounce - sets @debounce time for a @gpio
1212 * @gpio: the gpio to set debounce time
1213 * @debounce: debounce time is microseconds
1215 * returns -ENOTSUPP if the controller does not support setting
1218 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1220 struct gpio_chip *chip;
1222 if (!desc || !desc->chip) {
1223 pr_warn("%s: invalid GPIO\n", __func__);
1228 if (!chip->set || !chip->set_debounce) {
1230 "%s: missing set() or set_debounce() operations\n",
1235 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1237 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1240 * gpiod_is_active_low - test whether a GPIO is active-low or not
1241 * @desc: the gpio descriptor to test
1243 * Returns 1 if the GPIO is active-low, 0 otherwise.
1245 int gpiod_is_active_low(const struct gpio_desc *desc)
1247 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1249 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1251 /* I/O calls are only valid after configuration completed; the relevant
1252 * "is this a valid GPIO" error checks should already have been done.
1254 * "Get" operations are often inlinable as reading a pin value register,
1255 * and masking the relevant bit in that register.
1257 * When "set" operations are inlinable, they involve writing that mask to
1258 * one register to set a low value, or a different register to set it high.
1259 * Otherwise locking is needed, so there may be little value to inlining.
1261 *------------------------------------------------------------------------
1263 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1264 * have requested the GPIO. That can include implicit requesting by
1265 * a direction setting call. Marking a gpio as requested locks its chip
1266 * in memory, guaranteeing that these table lookups need no more locking
1267 * and that gpiochip_remove() will fail.
1269 * REVISIT when debugging, consider adding some instrumentation to ensure
1270 * that the GPIO was actually requested.
1273 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
1275 struct gpio_chip *chip;
1280 offset = gpio_chip_hwgpio(desc);
1281 value = chip->get ? chip->get(chip, offset) : -EIO;
1283 * FIXME: fix all drivers to clamp to [0,1] or return negative,
1284 * then change this to:
1285 * value = value < 0 ? value : !!value;
1286 * so we can properly propagate error codes.
1289 trace_gpio_value(desc_to_gpio(desc), 1, value);
1294 * gpiod_get_raw_value() - return a gpio's raw value
1295 * @desc: gpio whose value will be returned
1297 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1298 * its ACTIVE_LOW status, or negative errno on failure.
1300 * This function should be called from contexts where we cannot sleep, and will
1301 * complain if the GPIO chip functions potentially sleep.
1303 int gpiod_get_raw_value(const struct gpio_desc *desc)
1307 /* Should be using gpio_get_value_cansleep() */
1308 WARN_ON(desc->chip->can_sleep);
1309 return _gpiod_get_raw_value(desc);
1311 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1314 * gpiod_get_value() - return a gpio's value
1315 * @desc: gpio whose value will be returned
1317 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1318 * account, or negative errno on failure.
1320 * This function should be called from contexts where we cannot sleep, and will
1321 * complain if the GPIO chip functions potentially sleep.
1323 int gpiod_get_value(const struct gpio_desc *desc)
1328 /* Should be using gpio_get_value_cansleep() */
1329 WARN_ON(desc->chip->can_sleep);
1331 value = _gpiod_get_raw_value(desc);
1335 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1340 EXPORT_SYMBOL_GPL(gpiod_get_value);
1343 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1344 * @desc: gpio descriptor whose state need to be set.
1345 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1347 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1350 struct gpio_chip *chip = desc->chip;
1351 int offset = gpio_chip_hwgpio(desc);
1354 err = chip->direction_input(chip, offset);
1356 clear_bit(FLAG_IS_OUT, &desc->flags);
1358 err = chip->direction_output(chip, offset, 0);
1360 set_bit(FLAG_IS_OUT, &desc->flags);
1362 trace_gpio_direction(desc_to_gpio(desc), value, err);
1365 "%s: Error in set_value for open drain err %d\n",
1370 * _gpio_set_open_source_value() - Set the open source gpio's value.
1371 * @desc: gpio descriptor whose state need to be set.
1372 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1374 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1377 struct gpio_chip *chip = desc->chip;
1378 int offset = gpio_chip_hwgpio(desc);
1381 err = chip->direction_output(chip, offset, 1);
1383 set_bit(FLAG_IS_OUT, &desc->flags);
1385 err = chip->direction_input(chip, offset);
1387 clear_bit(FLAG_IS_OUT, &desc->flags);
1389 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1392 "%s: Error in set_value for open source err %d\n",
1396 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1398 struct gpio_chip *chip;
1401 trace_gpio_value(desc_to_gpio(desc), 0, value);
1402 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1403 _gpio_set_open_drain_value(desc, value);
1404 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1405 _gpio_set_open_source_value(desc, value);
1407 chip->set(chip, gpio_chip_hwgpio(desc), value);
1411 * set multiple outputs on the same chip;
1412 * use the chip's set_multiple function if available;
1413 * otherwise set the outputs sequentially;
1414 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1415 * defines which outputs are to be changed
1416 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1417 * defines the values the outputs specified by mask are to be set to
1419 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1420 unsigned long *mask, unsigned long *bits)
1422 if (chip->set_multiple) {
1423 chip->set_multiple(chip, mask, bits);
1426 for (i = 0; i < chip->ngpio; i++) {
1427 if (mask[BIT_WORD(i)] == 0) {
1428 /* no more set bits in this mask word;
1429 * skip ahead to the next word */
1430 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1433 /* set outputs if the corresponding mask bit is set */
1434 if (__test_and_clear_bit(i, mask))
1435 chip->set(chip, i, test_bit(i, bits));
1440 static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
1441 unsigned int array_size,
1442 struct gpio_desc **desc_array,
1447 while (i < array_size) {
1448 struct gpio_chip *chip = desc_array[i]->chip;
1449 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1450 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1454 WARN_ON(chip->can_sleep);
1456 memset(mask, 0, sizeof(mask));
1458 struct gpio_desc *desc = desc_array[i];
1459 int hwgpio = gpio_chip_hwgpio(desc);
1460 int value = value_array[i];
1462 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1464 trace_gpio_value(desc_to_gpio(desc), 0, value);
1466 * collect all normal outputs belonging to the same chip
1467 * open drain and open source outputs are set individually
1469 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1470 _gpio_set_open_drain_value(desc, value);
1471 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1472 _gpio_set_open_source_value(desc, value);
1474 __set_bit(hwgpio, mask);
1476 __set_bit(hwgpio, bits);
1478 __clear_bit(hwgpio, bits);
1482 } while ((i < array_size) && (desc_array[i]->chip == chip));
1483 /* push collected bits to outputs */
1485 gpio_chip_set_multiple(chip, mask, bits);
1490 * gpiod_set_raw_value() - assign a gpio's raw value
1491 * @desc: gpio whose value will be assigned
1492 * @value: value to assign
1494 * Set the raw value of the GPIO, i.e. the value of its physical line without
1495 * regard for its ACTIVE_LOW status.
1497 * This function should be called from contexts where we cannot sleep, and will
1498 * complain if the GPIO chip functions potentially sleep.
1500 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1504 /* Should be using gpio_set_value_cansleep() */
1505 WARN_ON(desc->chip->can_sleep);
1506 _gpiod_set_raw_value(desc, value);
1508 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1511 * gpiod_set_value() - assign a gpio's value
1512 * @desc: gpio whose value will be assigned
1513 * @value: value to assign
1515 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1518 * This function should be called from contexts where we cannot sleep, and will
1519 * complain if the GPIO chip functions potentially sleep.
1521 void gpiod_set_value(struct gpio_desc *desc, int value)
1525 /* Should be using gpio_set_value_cansleep() */
1526 WARN_ON(desc->chip->can_sleep);
1527 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1529 _gpiod_set_raw_value(desc, value);
1531 EXPORT_SYMBOL_GPL(gpiod_set_value);
1534 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1535 * @array_size: number of elements in the descriptor / value arrays
1536 * @desc_array: array of GPIO descriptors whose values will be assigned
1537 * @value_array: array of values to assign
1539 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1540 * without regard for their ACTIVE_LOW status.
1542 * This function should be called from contexts where we cannot sleep, and will
1543 * complain if the GPIO chip functions potentially sleep.
1545 void gpiod_set_raw_array_value(unsigned int array_size,
1546 struct gpio_desc **desc_array, int *value_array)
1550 gpiod_set_array_value_priv(true, false, array_size, desc_array,
1553 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
1556 * gpiod_set_array_value() - assign values to an array of GPIOs
1557 * @array_size: number of elements in the descriptor / value arrays
1558 * @desc_array: array of GPIO descriptors whose values will be assigned
1559 * @value_array: array of values to assign
1561 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1564 * This function should be called from contexts where we cannot sleep, and will
1565 * complain if the GPIO chip functions potentially sleep.
1567 void gpiod_set_array_value(unsigned int array_size,
1568 struct gpio_desc **desc_array, int *value_array)
1572 gpiod_set_array_value_priv(false, false, array_size, desc_array,
1575 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
1578 * gpiod_cansleep() - report whether gpio value access may sleep
1579 * @desc: gpio to check
1582 int gpiod_cansleep(const struct gpio_desc *desc)
1586 return desc->chip->can_sleep;
1588 EXPORT_SYMBOL_GPL(gpiod_cansleep);
1591 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1592 * @desc: gpio whose IRQ will be returned (already requested)
1594 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1597 int gpiod_to_irq(const struct gpio_desc *desc)
1599 struct gpio_chip *chip;
1605 offset = gpio_chip_hwgpio(desc);
1606 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
1608 EXPORT_SYMBOL_GPL(gpiod_to_irq);
1611 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1612 * @chip: the chip the GPIO to lock belongs to
1613 * @offset: the offset of the GPIO to lock as IRQ
1615 * This is used directly by GPIO drivers that want to lock down
1616 * a certain GPIO line to be used for IRQs.
1618 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
1620 if (offset >= chip->ngpio)
1623 if (test_bit(FLAG_IS_OUT, &chip->desc[offset].flags)) {
1625 "%s: tried to flag a GPIO set as output for IRQ\n",
1630 set_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1633 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
1636 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1637 * @chip: the chip the GPIO to lock belongs to
1638 * @offset: the offset of the GPIO to lock as IRQ
1640 * This is used directly by GPIO drivers that want to indicate
1641 * that a certain GPIO is no longer used exclusively for IRQ.
1643 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
1645 if (offset >= chip->ngpio)
1648 clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1650 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
1653 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1654 * @desc: gpio whose value will be returned
1656 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1657 * its ACTIVE_LOW status, or negative errno on failure.
1659 * This function is to be called from contexts that can sleep.
1661 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
1663 might_sleep_if(extra_checks);
1666 return _gpiod_get_raw_value(desc);
1668 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
1671 * gpiod_get_value_cansleep() - return a gpio's value
1672 * @desc: gpio whose value will be returned
1674 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1675 * account, or negative errno on failure.
1677 * This function is to be called from contexts that can sleep.
1679 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
1683 might_sleep_if(extra_checks);
1687 value = _gpiod_get_raw_value(desc);
1691 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1696 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
1699 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
1700 * @desc: gpio whose value will be assigned
1701 * @value: value to assign
1703 * Set the raw value of the GPIO, i.e. the value of its physical line without
1704 * regard for its ACTIVE_LOW status.
1706 * This function is to be called from contexts that can sleep.
1708 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
1710 might_sleep_if(extra_checks);
1713 _gpiod_set_raw_value(desc, value);
1715 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
1718 * gpiod_set_value_cansleep() - assign a gpio's value
1719 * @desc: gpio whose value will be assigned
1720 * @value: value to assign
1722 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1725 * This function is to be called from contexts that can sleep.
1727 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
1729 might_sleep_if(extra_checks);
1733 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1735 _gpiod_set_raw_value(desc, value);
1737 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
1740 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
1741 * @array_size: number of elements in the descriptor / value arrays
1742 * @desc_array: array of GPIO descriptors whose values will be assigned
1743 * @value_array: array of values to assign
1745 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1746 * without regard for their ACTIVE_LOW status.
1748 * This function is to be called from contexts that can sleep.
1750 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
1751 struct gpio_desc **desc_array,
1754 might_sleep_if(extra_checks);
1757 gpiod_set_array_value_priv(true, true, array_size, desc_array,
1760 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
1763 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
1764 * @array_size: number of elements in the descriptor / value arrays
1765 * @desc_array: array of GPIO descriptors whose values will be assigned
1766 * @value_array: array of values to assign
1768 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1771 * This function is to be called from contexts that can sleep.
1773 void gpiod_set_array_value_cansleep(unsigned int array_size,
1774 struct gpio_desc **desc_array,
1777 might_sleep_if(extra_checks);
1780 gpiod_set_array_value_priv(false, true, array_size, desc_array,
1783 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
1786 * gpiod_add_lookup_table() - register GPIO device consumers
1787 * @table: table of consumers to register
1789 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
1791 mutex_lock(&gpio_lookup_lock);
1793 list_add_tail(&table->list, &gpio_lookup_list);
1795 mutex_unlock(&gpio_lookup_lock);
1799 * gpiod_remove_lookup_table() - unregister GPIO device consumers
1800 * @table: table of consumers to unregister
1802 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
1804 mutex_lock(&gpio_lookup_lock);
1806 list_del(&table->list);
1808 mutex_unlock(&gpio_lookup_lock);
1811 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
1813 enum gpio_lookup_flags *flags)
1815 char prop_name[32]; /* 32 is max size of property name */
1816 enum of_gpio_flags of_flags;
1817 struct gpio_desc *desc;
1820 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1822 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
1825 snprintf(prop_name, sizeof(prop_name), "%s",
1828 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
1830 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1837 if (of_flags & OF_GPIO_ACTIVE_LOW)
1838 *flags |= GPIO_ACTIVE_LOW;
1840 if (of_flags & OF_GPIO_SINGLE_ENDED) {
1841 if (of_flags & OF_GPIO_ACTIVE_LOW)
1842 *flags |= GPIO_OPEN_DRAIN;
1844 *flags |= GPIO_OPEN_SOURCE;
1850 static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
1852 enum gpio_lookup_flags *flags)
1854 struct acpi_device *adev = ACPI_COMPANION(dev);
1855 struct acpi_gpio_info info;
1856 struct gpio_desc *desc;
1860 /* Try first from _DSD */
1861 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1862 if (con_id && strcmp(con_id, "gpios")) {
1863 snprintf(propname, sizeof(propname), "%s-%s",
1864 con_id, gpio_suffixes[i]);
1866 snprintf(propname, sizeof(propname), "%s",
1870 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
1871 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1875 /* Then from plain _CRS GPIOs */
1877 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
1882 if (info.active_low)
1883 *flags |= GPIO_ACTIVE_LOW;
1888 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
1890 const char *dev_id = dev ? dev_name(dev) : NULL;
1891 struct gpiod_lookup_table *table;
1893 mutex_lock(&gpio_lookup_lock);
1895 list_for_each_entry(table, &gpio_lookup_list, list) {
1896 if (table->dev_id && dev_id) {
1898 * Valid strings on both ends, must be identical to have
1901 if (!strcmp(table->dev_id, dev_id))
1905 * One of the pointers is NULL, so both must be to have
1908 if (dev_id == table->dev_id)
1915 mutex_unlock(&gpio_lookup_lock);
1919 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
1921 enum gpio_lookup_flags *flags)
1923 struct gpio_desc *desc = ERR_PTR(-ENOENT);
1924 struct gpiod_lookup_table *table;
1925 struct gpiod_lookup *p;
1927 table = gpiod_find_lookup_table(dev);
1931 for (p = &table->table[0]; p->chip_label; p++) {
1932 struct gpio_chip *chip;
1934 /* idx must always match exactly */
1938 /* If the lookup entry has a con_id, require exact match */
1939 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
1942 chip = find_chip_by_name(p->chip_label);
1945 dev_err(dev, "cannot find GPIO chip %s\n",
1947 return ERR_PTR(-ENODEV);
1950 if (chip->ngpio <= p->chip_hwnum) {
1952 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
1953 idx, p->chip_hwnum, chip->ngpio - 1,
1955 return ERR_PTR(-EINVAL);
1958 desc = gpiochip_get_desc(chip, p->chip_hwnum);
1967 static int dt_gpio_count(struct device *dev, const char *con_id)
1973 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1975 snprintf(propname, sizeof(propname), "%s-%s",
1976 con_id, gpio_suffixes[i]);
1978 snprintf(propname, sizeof(propname), "%s",
1981 ret = of_gpio_named_count(dev->of_node, propname);
1988 static int platform_gpio_count(struct device *dev, const char *con_id)
1990 struct gpiod_lookup_table *table;
1991 struct gpiod_lookup *p;
1992 unsigned int count = 0;
1994 table = gpiod_find_lookup_table(dev);
1998 for (p = &table->table[0]; p->chip_label; p++) {
1999 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
2000 (!con_id && !p->con_id))
2010 * gpiod_count - return the number of GPIOs associated with a device / function
2011 * or -ENOENT if no GPIO has been assigned to the requested function
2012 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2013 * @con_id: function within the GPIO consumer
2015 int gpiod_count(struct device *dev, const char *con_id)
2017 int count = -ENOENT;
2019 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
2020 count = dt_gpio_count(dev, con_id);
2021 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
2022 count = acpi_gpio_count(dev, con_id);
2025 count = platform_gpio_count(dev, con_id);
2029 EXPORT_SYMBOL_GPL(gpiod_count);
2032 * gpiod_get - obtain a GPIO for a given GPIO function
2033 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2034 * @con_id: function within the GPIO consumer
2035 * @flags: optional GPIO initialization flags
2037 * Return the GPIO descriptor corresponding to the function con_id of device
2038 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2039 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2041 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
2042 enum gpiod_flags flags)
2044 return gpiod_get_index(dev, con_id, 0, flags);
2046 EXPORT_SYMBOL_GPL(gpiod_get);
2049 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2050 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2051 * @con_id: function within the GPIO consumer
2052 * @flags: optional GPIO initialization flags
2054 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2055 * the requested function it will return NULL. This is convenient for drivers
2056 * that need to handle optional GPIOs.
2058 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
2060 enum gpiod_flags flags)
2062 return gpiod_get_index_optional(dev, con_id, 0, flags);
2064 EXPORT_SYMBOL_GPL(gpiod_get_optional);
2068 * gpiod_configure_flags - helper function to configure a given GPIO
2069 * @desc: gpio whose value will be assigned
2070 * @con_id: function within the GPIO consumer
2071 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2073 * @dflags: gpiod_flags - optional GPIO initialization flags
2075 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2076 * requested function and/or index, or another IS_ERR() code if an error
2077 * occurred while trying to acquire the GPIO.
2079 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
2080 unsigned long lflags, enum gpiod_flags dflags)
2084 if (lflags & GPIO_ACTIVE_LOW)
2085 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2086 if (lflags & GPIO_OPEN_DRAIN)
2087 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2088 if (lflags & GPIO_OPEN_SOURCE)
2089 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2091 /* No particular flag request, return here... */
2092 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
2093 pr_debug("no flags found for %s\n", con_id);
2098 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
2099 status = gpiod_direction_output(desc,
2100 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
2102 status = gpiod_direction_input(desc);
2108 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2109 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2110 * @con_id: function within the GPIO consumer
2111 * @idx: index of the GPIO to obtain in the consumer
2112 * @flags: optional GPIO initialization flags
2114 * This variant of gpiod_get() allows to access GPIOs other than the first
2115 * defined one for functions that define several GPIOs.
2117 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2118 * requested function and/or index, or another IS_ERR() code if an error
2119 * occurred while trying to acquire the GPIO.
2121 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2124 enum gpiod_flags flags)
2126 struct gpio_desc *desc = NULL;
2128 enum gpio_lookup_flags lookupflags = 0;
2129 /* Maybe we have a device name, maybe not */
2130 const char *devname = dev ? dev_name(dev) : "?";
2132 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2135 /* Using device tree? */
2136 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
2137 dev_dbg(dev, "using device tree for GPIO lookup\n");
2138 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
2139 } else if (ACPI_COMPANION(dev)) {
2140 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2141 desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
2146 * Either we are not using DT or ACPI, or their lookup did not return
2147 * a result. In that case, use platform lookup as a fallback.
2149 if (!desc || desc == ERR_PTR(-ENOENT)) {
2150 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2151 desc = gpiod_find(dev, con_id, idx, &lookupflags);
2155 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2160 * If a connection label was passed use that, else attempt to use
2161 * the device name as label
2163 status = gpiod_request(desc, con_id ? con_id : devname);
2165 return ERR_PTR(status);
2167 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
2169 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2171 return ERR_PTR(status);
2176 EXPORT_SYMBOL_GPL(gpiod_get_index);
2179 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2180 * @fwnode: handle of the firmware node
2181 * @propname: name of the firmware property representing the GPIO
2183 * This function can be used for drivers that get their configuration
2186 * Function properly finds the corresponding GPIO using whatever is the
2187 * underlying firmware interface and then makes sure that the GPIO
2188 * descriptor is requested before it is returned to the caller.
2190 * In case of error an ERR_PTR() is returned.
2192 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2193 const char *propname)
2195 struct gpio_desc *desc = ERR_PTR(-ENODEV);
2196 bool active_low = false;
2197 bool single_ended = false;
2201 return ERR_PTR(-EINVAL);
2203 if (is_of_node(fwnode)) {
2204 enum of_gpio_flags flags;
2206 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2208 if (!IS_ERR(desc)) {
2209 active_low = flags & OF_GPIO_ACTIVE_LOW;
2210 single_ended = flags & OF_GPIO_SINGLE_ENDED;
2212 } else if (is_acpi_node(fwnode)) {
2213 struct acpi_gpio_info info;
2215 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
2217 active_low = info.active_low;
2223 ret = gpiod_request(desc, NULL);
2225 return ERR_PTR(ret);
2228 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2232 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2234 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2239 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2242 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2244 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2245 * @con_id: function within the GPIO consumer
2246 * @index: index of the GPIO to obtain in the consumer
2247 * @flags: optional GPIO initialization flags
2249 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2250 * specified index was assigned to the requested function it will return NULL.
2251 * This is convenient for drivers that need to handle optional GPIOs.
2253 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2256 enum gpiod_flags flags)
2258 struct gpio_desc *desc;
2260 desc = gpiod_get_index(dev, con_id, index, flags);
2262 if (PTR_ERR(desc) == -ENOENT)
2268 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2271 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2272 * @desc: gpio whose value will be assigned
2273 * @name: gpio line name
2274 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2276 * @dflags: gpiod_flags - optional GPIO initialization flags
2278 int gpiod_hog(struct gpio_desc *desc, const char *name,
2279 unsigned long lflags, enum gpiod_flags dflags)
2281 struct gpio_chip *chip;
2282 struct gpio_desc *local_desc;
2286 chip = gpiod_to_chip(desc);
2287 hwnum = gpio_chip_hwgpio(desc);
2289 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2290 if (IS_ERR(local_desc)) {
2291 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2292 name, chip->label, hwnum);
2293 return PTR_ERR(local_desc);
2296 status = gpiod_configure_flags(desc, name, lflags, dflags);
2298 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2299 name, chip->label, hwnum);
2300 gpiochip_free_own_desc(desc);
2304 /* Mark GPIO as hogged so it can be identified and removed later */
2305 set_bit(FLAG_IS_HOGGED, &desc->flags);
2307 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2308 desc_to_gpio(desc), name,
2309 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2310 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2311 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2317 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2318 * @chip: gpio chip to act on
2320 * This is only used by of_gpiochip_remove to free hogged gpios
2322 static void gpiochip_free_hogs(struct gpio_chip *chip)
2326 for (id = 0; id < chip->ngpio; id++) {
2327 if (test_bit(FLAG_IS_HOGGED, &chip->desc[id].flags))
2328 gpiochip_free_own_desc(&chip->desc[id]);
2333 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2334 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2335 * @con_id: function within the GPIO consumer
2336 * @flags: optional GPIO initialization flags
2338 * This function acquires all the GPIOs defined under a given function.
2340 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2341 * no GPIO has been assigned to the requested function, or another IS_ERR()
2342 * code if an error occurred while trying to acquire the GPIOs.
2344 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2346 enum gpiod_flags flags)
2348 struct gpio_desc *desc;
2349 struct gpio_descs *descs;
2352 count = gpiod_count(dev, con_id);
2354 return ERR_PTR(count);
2356 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2359 return ERR_PTR(-ENOMEM);
2361 for (descs->ndescs = 0; descs->ndescs < count; ) {
2362 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2364 gpiod_put_array(descs);
2365 return ERR_CAST(desc);
2367 descs->desc[descs->ndescs] = desc;
2372 EXPORT_SYMBOL_GPL(gpiod_get_array);
2375 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2377 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2378 * @con_id: function within the GPIO consumer
2379 * @flags: optional GPIO initialization flags
2381 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2382 * assigned to the requested function it will return NULL.
2384 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2386 enum gpiod_flags flags)
2388 struct gpio_descs *descs;
2390 descs = gpiod_get_array(dev, con_id, flags);
2391 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2396 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2399 * gpiod_put - dispose of a GPIO descriptor
2400 * @desc: GPIO descriptor to dispose of
2402 * No descriptor can be used after gpiod_put() has been called on it.
2404 void gpiod_put(struct gpio_desc *desc)
2408 EXPORT_SYMBOL_GPL(gpiod_put);
2411 * gpiod_put_array - dispose of multiple GPIO descriptors
2412 * @descs: struct gpio_descs containing an array of descriptors
2414 void gpiod_put_array(struct gpio_descs *descs)
2418 for (i = 0; i < descs->ndescs; i++)
2419 gpiod_put(descs->desc[i]);
2423 EXPORT_SYMBOL_GPL(gpiod_put_array);
2425 #ifdef CONFIG_DEBUG_FS
2427 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2430 unsigned gpio = chip->base;
2431 struct gpio_desc *gdesc = &chip->desc[0];
2435 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2436 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
2438 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
2444 gpiod_get_direction(gdesc);
2445 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2446 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2447 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2448 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
2449 is_out ? "out" : "in ",
2451 ? (chip->get(chip, i) ? "hi" : "lo")
2453 is_irq ? "IRQ" : " ");
2454 seq_printf(s, "\n");
2458 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2460 unsigned long flags;
2461 struct gpio_chip *chip = NULL;
2462 loff_t index = *pos;
2466 spin_lock_irqsave(&gpio_lock, flags);
2467 list_for_each_entry(chip, &gpio_chips, list)
2469 spin_unlock_irqrestore(&gpio_lock, flags);
2472 spin_unlock_irqrestore(&gpio_lock, flags);
2477 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2479 unsigned long flags;
2480 struct gpio_chip *chip = v;
2483 spin_lock_irqsave(&gpio_lock, flags);
2484 if (list_is_last(&chip->list, &gpio_chips))
2487 ret = list_entry(chip->list.next, struct gpio_chip, list);
2488 spin_unlock_irqrestore(&gpio_lock, flags);
2496 static void gpiolib_seq_stop(struct seq_file *s, void *v)
2500 static int gpiolib_seq_show(struct seq_file *s, void *v)
2502 struct gpio_chip *chip = v;
2505 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2506 chip->base, chip->base + chip->ngpio - 1);
2509 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2512 seq_printf(s, ", %s", chip->label);
2513 if (chip->can_sleep)
2514 seq_printf(s, ", can sleep");
2515 seq_printf(s, ":\n");
2518 chip->dbg_show(s, chip);
2520 gpiolib_dbg_show(s, chip);
2525 static const struct seq_operations gpiolib_seq_ops = {
2526 .start = gpiolib_seq_start,
2527 .next = gpiolib_seq_next,
2528 .stop = gpiolib_seq_stop,
2529 .show = gpiolib_seq_show,
2532 static int gpiolib_open(struct inode *inode, struct file *file)
2534 return seq_open(file, &gpiolib_seq_ops);
2537 static const struct file_operations gpiolib_operations = {
2538 .owner = THIS_MODULE,
2539 .open = gpiolib_open,
2541 .llseek = seq_lseek,
2542 .release = seq_release,
2545 static int __init gpiolib_debugfs_init(void)
2547 /* /sys/kernel/debug/gpio */
2548 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2549 NULL, NULL, &gpiolib_operations);
2552 subsys_initcall(gpiolib_debugfs_init);
2554 #endif /* DEBUG_FS */