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>
21 #define CREATE_TRACE_POINTS
22 #include <trace/events/gpio.h>
24 /* Implementation infrastructure for GPIO interfaces.
26 * The GPIO programming interface allows for inlining speed-critical
27 * get/set operations for common cases, so that access to SOC-integrated
28 * GPIOs can sometimes cost only an instruction or two per bit.
32 /* When debugging, extend minimal trust to callers and platform code.
33 * Also emit diagnostic messages that may help initial bringup, when
34 * board setup or driver bugs are most common.
36 * Otherwise, minimize overhead in what may be bitbanging codepaths.
39 #define extra_checks 1
41 #define extra_checks 0
44 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
45 * While any GPIO is requested, its gpio_chip is not removable;
46 * each GPIO's "requested" flag serves as a lock and refcount.
48 DEFINE_SPINLOCK(gpio_lock);
50 #define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
52 static DEFINE_MUTEX(gpio_lookup_lock);
53 static LIST_HEAD(gpio_lookup_list);
54 LIST_HEAD(gpio_chips);
56 static inline void desc_set_label(struct gpio_desc *d, const char *label)
62 * Convert a GPIO number to its descriptor
64 struct gpio_desc *gpio_to_desc(unsigned gpio)
66 struct gpio_chip *chip;
69 spin_lock_irqsave(&gpio_lock, flags);
71 list_for_each_entry(chip, &gpio_chips, list) {
72 if (chip->base <= gpio && chip->base + chip->ngpio > gpio) {
73 spin_unlock_irqrestore(&gpio_lock, flags);
74 return &chip->desc[gpio - chip->base];
78 spin_unlock_irqrestore(&gpio_lock, flags);
80 if (!gpio_is_valid(gpio))
81 WARN(1, "invalid GPIO %d\n", gpio);
85 EXPORT_SYMBOL_GPL(gpio_to_desc);
88 * Get the GPIO descriptor corresponding to the given hw number for this chip.
90 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
93 if (hwnum >= chip->ngpio)
94 return ERR_PTR(-EINVAL);
96 return &chip->desc[hwnum];
100 * Convert a GPIO descriptor to the integer namespace.
101 * This should disappear in the future but is needed since we still
102 * use GPIO numbers for error messages and sysfs nodes
104 int desc_to_gpio(const struct gpio_desc *desc)
106 return desc->chip->base + (desc - &desc->chip->desc[0]);
108 EXPORT_SYMBOL_GPL(desc_to_gpio);
112 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
113 * @desc: descriptor to return the chip of
115 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
117 return desc ? desc->chip : NULL;
119 EXPORT_SYMBOL_GPL(gpiod_to_chip);
121 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
122 static int gpiochip_find_base(int ngpio)
124 struct gpio_chip *chip;
125 int base = ARCH_NR_GPIOS - ngpio;
127 list_for_each_entry_reverse(chip, &gpio_chips, list) {
128 /* found a free space? */
129 if (chip->base + chip->ngpio <= base)
132 /* nope, check the space right before the chip */
133 base = chip->base - ngpio;
136 if (gpio_is_valid(base)) {
137 pr_debug("%s: found new base at %d\n", __func__, base);
140 pr_err("%s: cannot find free range\n", __func__);
146 * gpiod_get_direction - return the current direction of a GPIO
147 * @desc: GPIO to get the direction of
149 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
151 * This function may sleep if gpiod_cansleep() is true.
153 int gpiod_get_direction(struct gpio_desc *desc)
155 struct gpio_chip *chip;
157 int status = -EINVAL;
159 chip = gpiod_to_chip(desc);
160 offset = gpio_chip_hwgpio(desc);
162 if (!chip->get_direction)
165 status = chip->get_direction(chip, offset);
167 /* GPIOF_DIR_IN, or other positive */
169 clear_bit(FLAG_IS_OUT, &desc->flags);
173 set_bit(FLAG_IS_OUT, &desc->flags);
177 EXPORT_SYMBOL_GPL(gpiod_get_direction);
180 * Add a new chip to the global chips list, keeping the list of chips sorted
183 * Return -EBUSY if the new chip overlaps with some other chip's integer
186 static int gpiochip_add_to_list(struct gpio_chip *chip)
188 struct list_head *pos = &gpio_chips;
189 struct gpio_chip *_chip;
192 /* find where to insert our chip */
193 list_for_each(pos, &gpio_chips) {
194 _chip = list_entry(pos, struct gpio_chip, list);
195 /* shall we insert before _chip? */
196 if (_chip->base >= chip->base + chip->ngpio)
200 /* are we stepping on the chip right before? */
201 if (pos != &gpio_chips && pos->prev != &gpio_chips) {
202 _chip = list_entry(pos->prev, struct gpio_chip, list);
203 if (_chip->base + _chip->ngpio > chip->base) {
205 "GPIO integer space overlap, cannot add chip\n");
211 list_add_tail(&chip->list, pos);
217 * gpiochip_add() - register a gpio_chip
218 * @chip: the chip to register, with chip->base initialized
219 * Context: potentially before irqs will work
221 * Returns a negative errno if the chip can't be registered, such as
222 * because the chip->base is invalid or already associated with a
223 * different chip. Otherwise it returns zero as a success code.
225 * When gpiochip_add() is called very early during boot, so that GPIOs
226 * can be freely used, the chip->dev device must be registered before
227 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
228 * for GPIOs will fail rudely.
230 * If chip->base is negative, this requests dynamic assignment of
231 * a range of valid GPIOs.
233 int gpiochip_add(struct gpio_chip *chip)
238 int base = chip->base;
239 struct gpio_desc *descs;
241 descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL);
245 spin_lock_irqsave(&gpio_lock, flags);
248 base = gpiochip_find_base(chip->ngpio);
251 spin_unlock_irqrestore(&gpio_lock, flags);
257 status = gpiochip_add_to_list(chip);
259 spin_unlock_irqrestore(&gpio_lock, flags);
263 for (id = 0; id < chip->ngpio; id++) {
264 struct gpio_desc *desc = &descs[id];
268 /* REVISIT: most hardware initializes GPIOs as inputs (often
269 * with pullups enabled) so power usage is minimized. Linux
270 * code should set the gpio direction first thing; but until
271 * it does, and in case chip->get_direction is not set, we may
272 * expose the wrong direction in sysfs.
274 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
279 spin_unlock_irqrestore(&gpio_lock, flags);
281 #ifdef CONFIG_PINCTRL
282 INIT_LIST_HEAD(&chip->pin_ranges);
285 of_gpiochip_add(chip);
286 acpi_gpiochip_add(chip);
288 status = gpiochip_export(chip);
290 goto err_remove_chip;
292 pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
293 chip->base, chip->base + chip->ngpio - 1,
294 chip->label ? : "generic");
299 acpi_gpiochip_remove(chip);
300 of_gpiochip_remove(chip);
301 spin_lock_irqsave(&gpio_lock, flags);
302 list_del(&chip->list);
303 spin_unlock_irqrestore(&gpio_lock, flags);
308 /* failures here can mean systems won't boot... */
309 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
310 chip->base, chip->base + chip->ngpio - 1,
311 chip->label ? : "generic");
314 EXPORT_SYMBOL_GPL(gpiochip_add);
316 /* Forward-declaration */
317 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
318 static void gpiochip_free_hogs(struct gpio_chip *chip);
321 * gpiochip_remove() - unregister a gpio_chip
322 * @chip: the chip to unregister
324 * A gpio_chip with any GPIOs still requested may not be removed.
326 void gpiochip_remove(struct gpio_chip *chip)
331 gpiochip_unexport(chip);
333 gpiochip_irqchip_remove(chip);
335 acpi_gpiochip_remove(chip);
336 gpiochip_remove_pin_ranges(chip);
337 gpiochip_free_hogs(chip);
338 of_gpiochip_remove(chip);
340 spin_lock_irqsave(&gpio_lock, flags);
341 for (id = 0; id < chip->ngpio; id++) {
342 if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
343 dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
345 for (id = 0; id < chip->ngpio; id++)
346 chip->desc[id].chip = NULL;
348 list_del(&chip->list);
349 spin_unlock_irqrestore(&gpio_lock, flags);
354 EXPORT_SYMBOL_GPL(gpiochip_remove);
357 * gpiochip_find() - iterator for locating a specific gpio_chip
358 * @data: data to pass to match function
359 * @callback: Callback function to check gpio_chip
361 * Similar to bus_find_device. It returns a reference to a gpio_chip as
362 * determined by a user supplied @match callback. The callback should return
363 * 0 if the device doesn't match and non-zero if it does. If the callback is
364 * non-zero, this function will return to the caller and not iterate over any
367 struct gpio_chip *gpiochip_find(void *data,
368 int (*match)(struct gpio_chip *chip,
371 struct gpio_chip *chip;
374 spin_lock_irqsave(&gpio_lock, flags);
375 list_for_each_entry(chip, &gpio_chips, list)
376 if (match(chip, data))
380 if (&chip->list == &gpio_chips)
382 spin_unlock_irqrestore(&gpio_lock, flags);
386 EXPORT_SYMBOL_GPL(gpiochip_find);
388 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
390 const char *name = data;
392 return !strcmp(chip->label, name);
395 static struct gpio_chip *find_chip_by_name(const char *name)
397 return gpiochip_find((void *)name, gpiochip_match_name);
400 #ifdef CONFIG_GPIOLIB_IRQCHIP
403 * The following is irqchip helper code for gpiochips.
407 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
408 * @gpiochip: the gpiochip to set the irqchip chain to
409 * @irqchip: the irqchip to chain to the gpiochip
410 * @parent_irq: the irq number corresponding to the parent IRQ for this
412 * @parent_handler: the parent interrupt handler for the accumulated IRQ
413 * coming out of the gpiochip. If the interrupt is nested rather than
414 * cascaded, pass NULL in this handler argument
416 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
417 struct irq_chip *irqchip,
419 irq_flow_handler_t parent_handler)
423 if (!gpiochip->irqdomain) {
424 chip_err(gpiochip, "called %s before setting up irqchip\n",
429 if (parent_handler) {
430 if (gpiochip->can_sleep) {
432 "you cannot have chained interrupts on a "
433 "chip that may sleep\n");
437 * The parent irqchip is already using the chip_data for this
438 * irqchip, so our callbacks simply use the handler_data.
440 irq_set_handler_data(parent_irq, gpiochip);
441 irq_set_chained_handler(parent_irq, parent_handler);
444 /* Set the parent IRQ for all affected IRQs */
445 for (offset = 0; offset < gpiochip->ngpio; offset++)
446 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
449 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
452 * This lock class tells lockdep that GPIO irqs are in a different
453 * category than their parents, so it won't report false recursion.
455 static struct lock_class_key gpiochip_irq_lock_class;
458 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
459 * @d: the irqdomain used by this irqchip
460 * @irq: the global irq number used by this GPIO irqchip irq
461 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
463 * This function will set up the mapping for a certain IRQ line on a
464 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
465 * stored inside the gpiochip.
467 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
468 irq_hw_number_t hwirq)
470 struct gpio_chip *chip = d->host_data;
472 irq_set_chip_data(irq, chip);
473 irq_set_lockdep_class(irq, &gpiochip_irq_lock_class);
474 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
475 /* Chips that can sleep need nested thread handlers */
476 if (chip->can_sleep && !chip->irq_not_threaded)
477 irq_set_nested_thread(irq, 1);
479 set_irq_flags(irq, IRQF_VALID);
481 irq_set_noprobe(irq);
484 * No set-up of the hardware will happen if IRQ_TYPE_NONE
485 * is passed as default type.
487 if (chip->irq_default_type != IRQ_TYPE_NONE)
488 irq_set_irq_type(irq, chip->irq_default_type);
493 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
495 struct gpio_chip *chip = d->host_data;
498 set_irq_flags(irq, 0);
501 irq_set_nested_thread(irq, 0);
502 irq_set_chip_and_handler(irq, NULL, NULL);
503 irq_set_chip_data(irq, NULL);
506 static const struct irq_domain_ops gpiochip_domain_ops = {
507 .map = gpiochip_irq_map,
508 .unmap = gpiochip_irq_unmap,
509 /* Virtually all GPIO irqchips are twocell:ed */
510 .xlate = irq_domain_xlate_twocell,
513 static int gpiochip_irq_reqres(struct irq_data *d)
515 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
517 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
519 "unable to lock HW IRQ %lu for IRQ\n",
526 static void gpiochip_irq_relres(struct irq_data *d)
528 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
530 gpiochip_unlock_as_irq(chip, d->hwirq);
533 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
535 return irq_find_mapping(chip->irqdomain, offset);
539 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
540 * @gpiochip: the gpiochip to remove the irqchip from
542 * This is called only from gpiochip_remove()
544 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
548 acpi_gpiochip_free_interrupts(gpiochip);
550 /* Remove all IRQ mappings and delete the domain */
551 if (gpiochip->irqdomain) {
552 for (offset = 0; offset < gpiochip->ngpio; offset++)
554 irq_find_mapping(gpiochip->irqdomain, offset));
555 irq_domain_remove(gpiochip->irqdomain);
558 if (gpiochip->irqchip) {
559 gpiochip->irqchip->irq_request_resources = NULL;
560 gpiochip->irqchip->irq_release_resources = NULL;
561 gpiochip->irqchip = NULL;
566 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
567 * @gpiochip: the gpiochip to add the irqchip to
568 * @irqchip: the irqchip to add to the gpiochip
569 * @first_irq: if not dynamically assigned, the base (first) IRQ to
570 * allocate gpiochip irqs from
571 * @handler: the irq handler to use (often a predefined irq core function)
572 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
573 * to have the core avoid setting up any default type in the hardware.
575 * This function closely associates a certain irqchip with a certain
576 * gpiochip, providing an irq domain to translate the local IRQs to
577 * global irqs in the gpiolib core, and making sure that the gpiochip
578 * is passed as chip data to all related functions. Driver callbacks
579 * need to use container_of() to get their local state containers back
580 * from the gpiochip passed as chip data. An irqdomain will be stored
581 * in the gpiochip that shall be used by the driver to handle IRQ number
582 * translation. The gpiochip will need to be initialized and registered
583 * before calling this function.
585 * This function will handle two cell:ed simple IRQs and assumes all
586 * the pins on the gpiochip can generate a unique IRQ. Everything else
587 * need to be open coded.
589 int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
590 struct irq_chip *irqchip,
591 unsigned int first_irq,
592 irq_flow_handler_t handler,
595 struct device_node *of_node;
597 unsigned irq_base = 0;
599 if (!gpiochip || !irqchip)
602 if (!gpiochip->dev) {
603 pr_err("missing gpiochip .dev parent pointer\n");
606 of_node = gpiochip->dev->of_node;
607 #ifdef CONFIG_OF_GPIO
609 * If the gpiochip has an assigned OF node this takes precendence
610 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
612 if (gpiochip->of_node)
613 of_node = gpiochip->of_node;
615 gpiochip->irqchip = irqchip;
616 gpiochip->irq_handler = handler;
617 gpiochip->irq_default_type = type;
618 gpiochip->to_irq = gpiochip_to_irq;
619 gpiochip->irqdomain = irq_domain_add_simple(of_node,
620 gpiochip->ngpio, first_irq,
621 &gpiochip_domain_ops, gpiochip);
622 if (!gpiochip->irqdomain) {
623 gpiochip->irqchip = NULL;
626 irqchip->irq_request_resources = gpiochip_irq_reqres;
627 irqchip->irq_release_resources = gpiochip_irq_relres;
630 * Prepare the mapping since the irqchip shall be orthogonal to
631 * any gpiochip calls. If the first_irq was zero, this is
632 * necessary to allocate descriptors for all IRQs.
634 for (offset = 0; offset < gpiochip->ngpio; offset++) {
635 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
638 * Store the base into the gpiochip to be used when
639 * unmapping the irqs.
641 gpiochip->irq_base = irq_base;
644 acpi_gpiochip_request_interrupts(gpiochip);
648 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
650 #else /* CONFIG_GPIOLIB_IRQCHIP */
652 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
654 #endif /* CONFIG_GPIOLIB_IRQCHIP */
656 #ifdef CONFIG_PINCTRL
659 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
660 * @chip: the gpiochip to add the range for
661 * @pinctrl: the dev_name() of the pin controller to map to
662 * @gpio_offset: the start offset in the current gpio_chip number space
663 * @pin_group: name of the pin group inside the pin controller
665 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
666 struct pinctrl_dev *pctldev,
667 unsigned int gpio_offset, const char *pin_group)
669 struct gpio_pin_range *pin_range;
672 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
674 chip_err(chip, "failed to allocate pin ranges\n");
678 /* Use local offset as range ID */
679 pin_range->range.id = gpio_offset;
680 pin_range->range.gc = chip;
681 pin_range->range.name = chip->label;
682 pin_range->range.base = chip->base + gpio_offset;
683 pin_range->pctldev = pctldev;
685 ret = pinctrl_get_group_pins(pctldev, pin_group,
686 &pin_range->range.pins,
687 &pin_range->range.npins);
693 pinctrl_add_gpio_range(pctldev, &pin_range->range);
695 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
696 gpio_offset, gpio_offset + pin_range->range.npins - 1,
697 pinctrl_dev_get_devname(pctldev), pin_group);
699 list_add_tail(&pin_range->node, &chip->pin_ranges);
703 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
706 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
707 * @chip: the gpiochip to add the range for
708 * @pinctrl_name: the dev_name() of the pin controller to map to
709 * @gpio_offset: the start offset in the current gpio_chip number space
710 * @pin_offset: the start offset in the pin controller number space
711 * @npins: the number of pins from the offset of each pin space (GPIO and
712 * pin controller) to accumulate in this range
714 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
715 unsigned int gpio_offset, unsigned int pin_offset,
718 struct gpio_pin_range *pin_range;
721 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
723 chip_err(chip, "failed to allocate pin ranges\n");
727 /* Use local offset as range ID */
728 pin_range->range.id = gpio_offset;
729 pin_range->range.gc = chip;
730 pin_range->range.name = chip->label;
731 pin_range->range.base = chip->base + gpio_offset;
732 pin_range->range.pin_base = pin_offset;
733 pin_range->range.npins = npins;
734 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
736 if (IS_ERR(pin_range->pctldev)) {
737 ret = PTR_ERR(pin_range->pctldev);
738 chip_err(chip, "could not create pin range\n");
742 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
743 gpio_offset, gpio_offset + npins - 1,
745 pin_offset, pin_offset + npins - 1);
747 list_add_tail(&pin_range->node, &chip->pin_ranges);
751 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
754 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
755 * @chip: the chip to remove all the mappings for
757 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
759 struct gpio_pin_range *pin_range, *tmp;
761 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
762 list_del(&pin_range->node);
763 pinctrl_remove_gpio_range(pin_range->pctldev,
768 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
770 #endif /* CONFIG_PINCTRL */
772 /* These "optional" allocation calls help prevent drivers from stomping
773 * on each other, and help provide better diagnostics in debugfs.
774 * They're called even less than the "set direction" calls.
776 static int __gpiod_request(struct gpio_desc *desc, const char *label)
778 struct gpio_chip *chip = desc->chip;
782 spin_lock_irqsave(&gpio_lock, flags);
784 /* NOTE: gpio_request() can be called in early boot,
785 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
788 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
789 desc_set_label(desc, label ? : "?");
797 /* chip->request may sleep */
798 spin_unlock_irqrestore(&gpio_lock, flags);
799 status = chip->request(chip, gpio_chip_hwgpio(desc));
800 spin_lock_irqsave(&gpio_lock, flags);
803 desc_set_label(desc, NULL);
804 clear_bit(FLAG_REQUESTED, &desc->flags);
808 if (chip->get_direction) {
809 /* chip->get_direction may sleep */
810 spin_unlock_irqrestore(&gpio_lock, flags);
811 gpiod_get_direction(desc);
812 spin_lock_irqsave(&gpio_lock, flags);
815 spin_unlock_irqrestore(&gpio_lock, flags);
819 int gpiod_request(struct gpio_desc *desc, const char *label)
821 int status = -EPROBE_DEFER;
822 struct gpio_chip *chip;
825 pr_warn("%s: invalid GPIO\n", __func__);
833 if (try_module_get(chip->owner)) {
834 status = __gpiod_request(desc, label);
836 module_put(chip->owner);
841 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
846 static bool __gpiod_free(struct gpio_desc *desc)
850 struct gpio_chip *chip;
854 gpiod_unexport(desc);
856 spin_lock_irqsave(&gpio_lock, flags);
859 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
861 spin_unlock_irqrestore(&gpio_lock, flags);
862 might_sleep_if(chip->can_sleep);
863 chip->free(chip, gpio_chip_hwgpio(desc));
864 spin_lock_irqsave(&gpio_lock, flags);
866 desc_set_label(desc, NULL);
867 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
868 clear_bit(FLAG_REQUESTED, &desc->flags);
869 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
870 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
871 clear_bit(FLAG_IS_HOGGED, &desc->flags);
875 spin_unlock_irqrestore(&gpio_lock, flags);
879 void gpiod_free(struct gpio_desc *desc)
881 if (desc && __gpiod_free(desc))
882 module_put(desc->chip->owner);
884 WARN_ON(extra_checks);
888 * gpiochip_is_requested - return string iff signal was requested
889 * @chip: controller managing the signal
890 * @offset: of signal within controller's 0..(ngpio - 1) range
892 * Returns NULL if the GPIO is not currently requested, else a string.
893 * The string returned is the label passed to gpio_request(); if none has been
894 * passed it is a meaningless, non-NULL constant.
896 * This function is for use by GPIO controller drivers. The label can
897 * help with diagnostics, and knowing that the signal is used as a GPIO
898 * can help avoid accidentally multiplexing it to another controller.
900 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
902 struct gpio_desc *desc;
904 if (!GPIO_OFFSET_VALID(chip, offset))
907 desc = &chip->desc[offset];
909 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
913 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
916 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
917 * @desc: GPIO descriptor to request
918 * @label: label for the GPIO
920 * Function allows GPIO chip drivers to request and use their own GPIO
921 * descriptors via gpiolib API. Difference to gpiod_request() is that this
922 * function will not increase reference count of the GPIO chip module. This
923 * allows the GPIO chip module to be unloaded as needed (we assume that the
924 * GPIO chip driver handles freeing the GPIOs it has requested).
926 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
929 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
933 chip_err(chip, "failed to get GPIO descriptor\n");
937 err = __gpiod_request(desc, label);
943 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
946 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
947 * @desc: GPIO descriptor to free
949 * Function frees the given GPIO requested previously with
950 * gpiochip_request_own_desc().
952 void gpiochip_free_own_desc(struct gpio_desc *desc)
957 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
959 /* Drivers MUST set GPIO direction before making get/set calls. In
960 * some cases this is done in early boot, before IRQs are enabled.
962 * As a rule these aren't called more than once (except for drivers
963 * using the open-drain emulation idiom) so these are natural places
964 * to accumulate extra debugging checks. Note that we can't (yet)
965 * rely on gpio_request() having been called beforehand.
969 * gpiod_direction_input - set the GPIO direction to input
970 * @desc: GPIO to set to input
972 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
973 * be called safely on it.
975 * Return 0 in case of success, else an error code.
977 int gpiod_direction_input(struct gpio_desc *desc)
979 struct gpio_chip *chip;
980 int status = -EINVAL;
982 if (!desc || !desc->chip) {
983 pr_warn("%s: invalid GPIO\n", __func__);
988 if (!chip->get || !chip->direction_input) {
990 "%s: missing get() or direction_input() operations\n",
995 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
997 clear_bit(FLAG_IS_OUT, &desc->flags);
999 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1003 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1005 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1007 struct gpio_chip *chip;
1008 int status = -EINVAL;
1010 /* GPIOs used for IRQs shall not be set as output */
1011 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1013 "%s: tried to set a GPIO tied to an IRQ as output\n",
1018 /* Open drain pin should not be driven to 1 */
1019 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1020 return gpiod_direction_input(desc);
1022 /* Open source pin should not be driven to 0 */
1023 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1024 return gpiod_direction_input(desc);
1027 if (!chip->set || !chip->direction_output) {
1029 "%s: missing set() or direction_output() operations\n",
1034 status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
1036 set_bit(FLAG_IS_OUT, &desc->flags);
1037 trace_gpio_value(desc_to_gpio(desc), 0, value);
1038 trace_gpio_direction(desc_to_gpio(desc), 0, status);
1043 * gpiod_direction_output_raw - set the GPIO direction to output
1044 * @desc: GPIO to set to output
1045 * @value: initial output value of the GPIO
1047 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1048 * be called safely on it. The initial value of the output must be specified
1049 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1051 * Return 0 in case of success, else an error code.
1053 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1055 if (!desc || !desc->chip) {
1056 pr_warn("%s: invalid GPIO\n", __func__);
1059 return _gpiod_direction_output_raw(desc, value);
1061 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1064 * gpiod_direction_output - set the GPIO direction to output
1065 * @desc: GPIO to set to output
1066 * @value: initial output value of the GPIO
1068 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1069 * be called safely on it. The initial value of the output must be specified
1070 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1073 * Return 0 in case of success, else an error code.
1075 int gpiod_direction_output(struct gpio_desc *desc, int value)
1077 if (!desc || !desc->chip) {
1078 pr_warn("%s: invalid GPIO\n", __func__);
1081 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1083 return _gpiod_direction_output_raw(desc, value);
1085 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1088 * gpiod_set_debounce - sets @debounce time for a @gpio
1089 * @gpio: the gpio to set debounce time
1090 * @debounce: debounce time is microseconds
1092 * returns -ENOTSUPP if the controller does not support setting
1095 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1097 struct gpio_chip *chip;
1099 if (!desc || !desc->chip) {
1100 pr_warn("%s: invalid GPIO\n", __func__);
1105 if (!chip->set || !chip->set_debounce) {
1107 "%s: missing set() or set_debounce() operations\n",
1112 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1114 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1117 * gpiod_is_active_low - test whether a GPIO is active-low or not
1118 * @desc: the gpio descriptor to test
1120 * Returns 1 if the GPIO is active-low, 0 otherwise.
1122 int gpiod_is_active_low(const struct gpio_desc *desc)
1124 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1126 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1128 /* I/O calls are only valid after configuration completed; the relevant
1129 * "is this a valid GPIO" error checks should already have been done.
1131 * "Get" operations are often inlinable as reading a pin value register,
1132 * and masking the relevant bit in that register.
1134 * When "set" operations are inlinable, they involve writing that mask to
1135 * one register to set a low value, or a different register to set it high.
1136 * Otherwise locking is needed, so there may be little value to inlining.
1138 *------------------------------------------------------------------------
1140 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1141 * have requested the GPIO. That can include implicit requesting by
1142 * a direction setting call. Marking a gpio as requested locks its chip
1143 * in memory, guaranteeing that these table lookups need no more locking
1144 * and that gpiochip_remove() will fail.
1146 * REVISIT when debugging, consider adding some instrumentation to ensure
1147 * that the GPIO was actually requested.
1150 static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
1152 struct gpio_chip *chip;
1157 offset = gpio_chip_hwgpio(desc);
1158 value = chip->get ? chip->get(chip, offset) : false;
1159 trace_gpio_value(desc_to_gpio(desc), 1, value);
1164 * gpiod_get_raw_value() - return a gpio's raw value
1165 * @desc: gpio whose value will be returned
1167 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1168 * its ACTIVE_LOW status.
1170 * This function should be called from contexts where we cannot sleep, and will
1171 * complain if the GPIO chip functions potentially sleep.
1173 int gpiod_get_raw_value(const struct gpio_desc *desc)
1177 /* Should be using gpio_get_value_cansleep() */
1178 WARN_ON(desc->chip->can_sleep);
1179 return _gpiod_get_raw_value(desc);
1181 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1184 * gpiod_get_value() - return a gpio's value
1185 * @desc: gpio whose value will be returned
1187 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1190 * This function should be called from contexts where we cannot sleep, and will
1191 * complain if the GPIO chip functions potentially sleep.
1193 int gpiod_get_value(const struct gpio_desc *desc)
1198 /* Should be using gpio_get_value_cansleep() */
1199 WARN_ON(desc->chip->can_sleep);
1201 value = _gpiod_get_raw_value(desc);
1202 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1207 EXPORT_SYMBOL_GPL(gpiod_get_value);
1210 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1211 * @desc: gpio descriptor whose state need to be set.
1212 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
1214 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1217 struct gpio_chip *chip = desc->chip;
1218 int offset = gpio_chip_hwgpio(desc);
1221 err = chip->direction_input(chip, offset);
1223 clear_bit(FLAG_IS_OUT, &desc->flags);
1225 err = chip->direction_output(chip, offset, 0);
1227 set_bit(FLAG_IS_OUT, &desc->flags);
1229 trace_gpio_direction(desc_to_gpio(desc), value, err);
1232 "%s: Error in set_value for open drain err %d\n",
1237 * _gpio_set_open_source_value() - Set the open source gpio's value.
1238 * @desc: gpio descriptor whose state need to be set.
1239 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
1241 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1244 struct gpio_chip *chip = desc->chip;
1245 int offset = gpio_chip_hwgpio(desc);
1248 err = chip->direction_output(chip, offset, 1);
1250 set_bit(FLAG_IS_OUT, &desc->flags);
1252 err = chip->direction_input(chip, offset);
1254 clear_bit(FLAG_IS_OUT, &desc->flags);
1256 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1259 "%s: Error in set_value for open source err %d\n",
1263 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1265 struct gpio_chip *chip;
1268 trace_gpio_value(desc_to_gpio(desc), 0, value);
1269 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1270 _gpio_set_open_drain_value(desc, value);
1271 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1272 _gpio_set_open_source_value(desc, value);
1274 chip->set(chip, gpio_chip_hwgpio(desc), value);
1278 * set multiple outputs on the same chip;
1279 * use the chip's set_multiple function if available;
1280 * otherwise set the outputs sequentially;
1281 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1282 * defines which outputs are to be changed
1283 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1284 * defines the values the outputs specified by mask are to be set to
1286 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1287 unsigned long *mask, unsigned long *bits)
1289 if (chip->set_multiple) {
1290 chip->set_multiple(chip, mask, bits);
1293 for (i = 0; i < chip->ngpio; i++) {
1294 if (mask[BIT_WORD(i)] == 0) {
1295 /* no more set bits in this mask word;
1296 * skip ahead to the next word */
1297 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1300 /* set outputs if the corresponding mask bit is set */
1301 if (__test_and_clear_bit(i, mask)) {
1302 chip->set(chip, i, test_bit(i, bits));
1308 static void gpiod_set_array_priv(bool raw, bool can_sleep,
1309 unsigned int array_size,
1310 struct gpio_desc **desc_array,
1315 while (i < array_size) {
1316 struct gpio_chip *chip = desc_array[i]->chip;
1317 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1318 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1322 WARN_ON(chip->can_sleep);
1324 memset(mask, 0, sizeof(mask));
1326 struct gpio_desc *desc = desc_array[i];
1327 int hwgpio = gpio_chip_hwgpio(desc);
1328 int value = value_array[i];
1330 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1332 trace_gpio_value(desc_to_gpio(desc), 0, value);
1334 * collect all normal outputs belonging to the same chip
1335 * open drain and open source outputs are set individually
1337 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1338 _gpio_set_open_drain_value(desc,value);
1339 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1340 _gpio_set_open_source_value(desc, value);
1342 __set_bit(hwgpio, mask);
1344 __set_bit(hwgpio, bits);
1346 __clear_bit(hwgpio, bits);
1351 } while ((i < array_size) && (desc_array[i]->chip == chip));
1352 /* push collected bits to outputs */
1354 gpio_chip_set_multiple(chip, mask, bits);
1360 * gpiod_set_raw_value() - assign a gpio's raw value
1361 * @desc: gpio whose value will be assigned
1362 * @value: value to assign
1364 * Set the raw value of the GPIO, i.e. the value of its physical line without
1365 * regard for its ACTIVE_LOW status.
1367 * This function should be called from contexts where we cannot sleep, and will
1368 * complain if the GPIO chip functions potentially sleep.
1370 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1374 /* Should be using gpio_set_value_cansleep() */
1375 WARN_ON(desc->chip->can_sleep);
1376 _gpiod_set_raw_value(desc, value);
1378 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1381 * gpiod_set_value() - assign a gpio's value
1382 * @desc: gpio whose value will be assigned
1383 * @value: value to assign
1385 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1388 * This function should be called from contexts where we cannot sleep, and will
1389 * complain if the GPIO chip functions potentially sleep.
1391 void gpiod_set_value(struct gpio_desc *desc, int value)
1395 /* Should be using gpio_set_value_cansleep() */
1396 WARN_ON(desc->chip->can_sleep);
1397 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1399 _gpiod_set_raw_value(desc, value);
1401 EXPORT_SYMBOL_GPL(gpiod_set_value);
1404 * gpiod_set_raw_array() - assign values to an array of GPIOs
1405 * @array_size: number of elements in the descriptor / value arrays
1406 * @desc_array: array of GPIO descriptors whose values will be assigned
1407 * @value_array: array of values to assign
1409 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1410 * without regard for their ACTIVE_LOW status.
1412 * This function should be called from contexts where we cannot sleep, and will
1413 * complain if the GPIO chip functions potentially sleep.
1415 void gpiod_set_raw_array(unsigned int array_size,
1416 struct gpio_desc **desc_array, int *value_array)
1420 gpiod_set_array_priv(true, false, array_size, desc_array, value_array);
1422 EXPORT_SYMBOL_GPL(gpiod_set_raw_array);
1425 * gpiod_set_array() - assign values to an array of GPIOs
1426 * @array_size: number of elements in the descriptor / value arrays
1427 * @desc_array: array of GPIO descriptors whose values will be assigned
1428 * @value_array: array of values to assign
1430 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1433 * This function should be called from contexts where we cannot sleep, and will
1434 * complain if the GPIO chip functions potentially sleep.
1436 void gpiod_set_array(unsigned int array_size,
1437 struct gpio_desc **desc_array, int *value_array)
1441 gpiod_set_array_priv(false, false, array_size, desc_array, value_array);
1443 EXPORT_SYMBOL_GPL(gpiod_set_array);
1446 * gpiod_cansleep() - report whether gpio value access may sleep
1447 * @desc: gpio to check
1450 int gpiod_cansleep(const struct gpio_desc *desc)
1454 return desc->chip->can_sleep;
1456 EXPORT_SYMBOL_GPL(gpiod_cansleep);
1459 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1460 * @desc: gpio whose IRQ will be returned (already requested)
1462 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1465 int gpiod_to_irq(const struct gpio_desc *desc)
1467 struct gpio_chip *chip;
1473 offset = gpio_chip_hwgpio(desc);
1474 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
1476 EXPORT_SYMBOL_GPL(gpiod_to_irq);
1479 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1480 * @chip: the chip the GPIO to lock belongs to
1481 * @offset: the offset of the GPIO to lock as IRQ
1483 * This is used directly by GPIO drivers that want to lock down
1484 * a certain GPIO line to be used for IRQs.
1486 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
1488 if (offset >= chip->ngpio)
1491 if (test_bit(FLAG_IS_OUT, &chip->desc[offset].flags)) {
1493 "%s: tried to flag a GPIO set as output for IRQ\n",
1498 set_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1501 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
1504 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1505 * @chip: the chip the GPIO to lock belongs to
1506 * @offset: the offset of the GPIO to lock as IRQ
1508 * This is used directly by GPIO drivers that want to indicate
1509 * that a certain GPIO is no longer used exclusively for IRQ.
1511 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
1513 if (offset >= chip->ngpio)
1516 clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1518 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
1521 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1522 * @desc: gpio whose value will be returned
1524 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1525 * its ACTIVE_LOW status.
1527 * This function is to be called from contexts that can sleep.
1529 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
1531 might_sleep_if(extra_checks);
1534 return _gpiod_get_raw_value(desc);
1536 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
1539 * gpiod_get_value_cansleep() - return a gpio's value
1540 * @desc: gpio whose value will be returned
1542 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1545 * This function is to be called from contexts that can sleep.
1547 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
1551 might_sleep_if(extra_checks);
1555 value = _gpiod_get_raw_value(desc);
1556 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1561 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
1564 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
1565 * @desc: gpio whose value will be assigned
1566 * @value: value to assign
1568 * Set the raw value of the GPIO, i.e. the value of its physical line without
1569 * regard for its ACTIVE_LOW status.
1571 * This function is to be called from contexts that can sleep.
1573 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
1575 might_sleep_if(extra_checks);
1578 _gpiod_set_raw_value(desc, value);
1580 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
1583 * gpiod_set_value_cansleep() - assign a gpio's value
1584 * @desc: gpio whose value will be assigned
1585 * @value: value to assign
1587 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1590 * This function is to be called from contexts that can sleep.
1592 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
1594 might_sleep_if(extra_checks);
1598 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1600 _gpiod_set_raw_value(desc, value);
1602 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
1605 * gpiod_set_raw_array_cansleep() - assign values to an array of GPIOs
1606 * @array_size: number of elements in the descriptor / value arrays
1607 * @desc_array: array of GPIO descriptors whose values will be assigned
1608 * @value_array: array of values to assign
1610 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1611 * without regard for their ACTIVE_LOW status.
1613 * This function is to be called from contexts that can sleep.
1615 void gpiod_set_raw_array_cansleep(unsigned int array_size,
1616 struct gpio_desc **desc_array,
1619 might_sleep_if(extra_checks);
1622 gpiod_set_array_priv(true, true, array_size, desc_array, value_array);
1624 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_cansleep);
1627 * gpiod_set_array_cansleep() - assign values to an array of GPIOs
1628 * @array_size: number of elements in the descriptor / value arrays
1629 * @desc_array: array of GPIO descriptors whose values will be assigned
1630 * @value_array: array of values to assign
1632 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1635 * This function is to be called from contexts that can sleep.
1637 void gpiod_set_array_cansleep(unsigned int array_size,
1638 struct gpio_desc **desc_array,
1641 might_sleep_if(extra_checks);
1644 gpiod_set_array_priv(false, true, array_size, desc_array, value_array);
1646 EXPORT_SYMBOL_GPL(gpiod_set_array_cansleep);
1649 * gpiod_add_lookup_table() - register GPIO device consumers
1650 * @table: table of consumers to register
1652 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
1654 mutex_lock(&gpio_lookup_lock);
1656 list_add_tail(&table->list, &gpio_lookup_list);
1658 mutex_unlock(&gpio_lookup_lock);
1661 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
1663 enum gpio_lookup_flags *flags)
1665 static const char * const suffixes[] = { "gpios", "gpio" };
1666 char prop_name[32]; /* 32 is max size of property name */
1667 enum of_gpio_flags of_flags;
1668 struct gpio_desc *desc;
1671 for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
1673 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
1676 snprintf(prop_name, sizeof(prop_name), "%s",
1679 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
1681 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1688 if (of_flags & OF_GPIO_ACTIVE_LOW)
1689 *flags |= GPIO_ACTIVE_LOW;
1694 static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
1696 enum gpio_lookup_flags *flags)
1698 static const char * const suffixes[] = { "gpios", "gpio" };
1699 struct acpi_device *adev = ACPI_COMPANION(dev);
1700 struct acpi_gpio_info info;
1701 struct gpio_desc *desc;
1705 /* Try first from _DSD */
1706 for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
1707 if (con_id && strcmp(con_id, "gpios")) {
1708 snprintf(propname, sizeof(propname), "%s-%s",
1709 con_id, suffixes[i]);
1711 snprintf(propname, sizeof(propname), "%s",
1715 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
1716 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1720 /* Then from plain _CRS GPIOs */
1722 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
1727 if (info.active_low)
1728 *flags |= GPIO_ACTIVE_LOW;
1733 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
1735 const char *dev_id = dev ? dev_name(dev) : NULL;
1736 struct gpiod_lookup_table *table;
1738 mutex_lock(&gpio_lookup_lock);
1740 list_for_each_entry(table, &gpio_lookup_list, list) {
1741 if (table->dev_id && dev_id) {
1743 * Valid strings on both ends, must be identical to have
1746 if (!strcmp(table->dev_id, dev_id))
1750 * One of the pointers is NULL, so both must be to have
1753 if (dev_id == table->dev_id)
1760 mutex_unlock(&gpio_lookup_lock);
1764 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
1766 enum gpio_lookup_flags *flags)
1768 struct gpio_desc *desc = ERR_PTR(-ENOENT);
1769 struct gpiod_lookup_table *table;
1770 struct gpiod_lookup *p;
1772 table = gpiod_find_lookup_table(dev);
1776 for (p = &table->table[0]; p->chip_label; p++) {
1777 struct gpio_chip *chip;
1779 /* idx must always match exactly */
1783 /* If the lookup entry has a con_id, require exact match */
1784 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
1787 chip = find_chip_by_name(p->chip_label);
1790 dev_err(dev, "cannot find GPIO chip %s\n",
1792 return ERR_PTR(-ENODEV);
1795 if (chip->ngpio <= p->chip_hwnum) {
1797 "requested GPIO %d is out of range [0..%d] for chip %s\n",
1798 idx, chip->ngpio, chip->label);
1799 return ERR_PTR(-EINVAL);
1802 desc = gpiochip_get_desc(chip, p->chip_hwnum);
1812 * gpiod_get - obtain a GPIO for a given GPIO function
1813 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1814 * @con_id: function within the GPIO consumer
1815 * @flags: optional GPIO initialization flags
1817 * Return the GPIO descriptor corresponding to the function con_id of device
1818 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
1819 * another IS_ERR() code if an error occured while trying to acquire the GPIO.
1821 struct gpio_desc *__must_check __gpiod_get(struct device *dev, const char *con_id,
1822 enum gpiod_flags flags)
1824 return gpiod_get_index(dev, con_id, 0, flags);
1826 EXPORT_SYMBOL_GPL(__gpiod_get);
1829 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
1830 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1831 * @con_id: function within the GPIO consumer
1832 * @flags: optional GPIO initialization flags
1834 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
1835 * the requested function it will return NULL. This is convenient for drivers
1836 * that need to handle optional GPIOs.
1838 struct gpio_desc *__must_check __gpiod_get_optional(struct device *dev,
1840 enum gpiod_flags flags)
1842 return gpiod_get_index_optional(dev, con_id, 0, flags);
1844 EXPORT_SYMBOL_GPL(__gpiod_get_optional);
1848 * gpiod_configure_flags - helper function to configure a given GPIO
1849 * @desc: gpio whose value will be assigned
1850 * @con_id: function within the GPIO consumer
1851 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
1853 * @dflags: gpiod_flags - optional GPIO initialization flags
1855 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
1856 * requested function and/or index, or another IS_ERR() code if an error
1857 * occurred while trying to acquire the GPIO.
1859 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
1860 unsigned long lflags, enum gpiod_flags dflags)
1864 if (lflags & GPIO_ACTIVE_LOW)
1865 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
1866 if (lflags & GPIO_OPEN_DRAIN)
1867 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
1868 if (lflags & GPIO_OPEN_SOURCE)
1869 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
1871 /* No particular flag request, return here... */
1872 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
1873 pr_debug("no flags found for %s\n", con_id);
1878 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
1879 status = gpiod_direction_output(desc,
1880 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
1882 status = gpiod_direction_input(desc);
1888 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
1889 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1890 * @con_id: function within the GPIO consumer
1891 * @idx: index of the GPIO to obtain in the consumer
1892 * @flags: optional GPIO initialization flags
1894 * This variant of gpiod_get() allows to access GPIOs other than the first
1895 * defined one for functions that define several GPIOs.
1897 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
1898 * requested function and/or index, or another IS_ERR() code if an error
1899 * occured while trying to acquire the GPIO.
1901 struct gpio_desc *__must_check __gpiod_get_index(struct device *dev,
1904 enum gpiod_flags flags)
1906 struct gpio_desc *desc = NULL;
1908 enum gpio_lookup_flags lookupflags = 0;
1910 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
1912 /* Using device tree? */
1913 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) {
1914 dev_dbg(dev, "using device tree for GPIO lookup\n");
1915 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
1916 } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
1917 dev_dbg(dev, "using ACPI for GPIO lookup\n");
1918 desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
1922 * Either we are not using DT or ACPI, or their lookup did not return
1923 * a result. In that case, use platform lookup as a fallback.
1925 if (!desc || desc == ERR_PTR(-ENOENT)) {
1926 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
1927 desc = gpiod_find(dev, con_id, idx, &lookupflags);
1931 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
1935 status = gpiod_request(desc, con_id);
1937 return ERR_PTR(status);
1939 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
1941 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
1943 return ERR_PTR(status);
1948 EXPORT_SYMBOL_GPL(__gpiod_get_index);
1951 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
1952 * @fwnode: handle of the firmware node
1953 * @propname: name of the firmware property representing the GPIO
1955 * This function can be used for drivers that get their configuration
1958 * Function properly finds the corresponding GPIO using whatever is the
1959 * underlying firmware interface and then makes sure that the GPIO
1960 * descriptor is requested before it is returned to the caller.
1962 * In case of error an ERR_PTR() is returned.
1964 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
1965 const char *propname)
1967 struct gpio_desc *desc = ERR_PTR(-ENODEV);
1968 bool active_low = false;
1972 return ERR_PTR(-EINVAL);
1974 if (is_of_node(fwnode)) {
1975 enum of_gpio_flags flags;
1977 desc = of_get_named_gpiod_flags(of_node(fwnode), propname, 0,
1980 active_low = flags & OF_GPIO_ACTIVE_LOW;
1981 } else if (is_acpi_node(fwnode)) {
1982 struct acpi_gpio_info info;
1984 desc = acpi_get_gpiod_by_index(acpi_node(fwnode), propname, 0,
1987 active_low = info.active_low;
1993 ret = gpiod_request(desc, NULL);
1995 return ERR_PTR(ret);
1997 /* Only value flag can be set from both DT and ACPI is active_low */
1999 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2003 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2006 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2008 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2009 * @con_id: function within the GPIO consumer
2010 * @index: index of the GPIO to obtain in the consumer
2011 * @flags: optional GPIO initialization flags
2013 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2014 * specified index was assigned to the requested function it will return NULL.
2015 * This is convenient for drivers that need to handle optional GPIOs.
2017 struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev,
2020 enum gpiod_flags flags)
2022 struct gpio_desc *desc;
2024 desc = gpiod_get_index(dev, con_id, index, flags);
2026 if (PTR_ERR(desc) == -ENOENT)
2032 EXPORT_SYMBOL_GPL(__gpiod_get_index_optional);
2035 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2036 * @desc: gpio whose value will be assigned
2037 * @name: gpio line name
2038 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2040 * @dflags: gpiod_flags - optional GPIO initialization flags
2042 int gpiod_hog(struct gpio_desc *desc, const char *name,
2043 unsigned long lflags, enum gpiod_flags dflags)
2045 struct gpio_chip *chip;
2046 struct gpio_desc *local_desc;
2050 chip = gpiod_to_chip(desc);
2051 hwnum = gpio_chip_hwgpio(desc);
2053 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2054 if (IS_ERR(local_desc)) {
2055 pr_debug("requesting own GPIO %s failed\n", name);
2056 return PTR_ERR(local_desc);
2059 status = gpiod_configure_flags(desc, name, lflags, dflags);
2061 pr_debug("setup of GPIO %s failed\n", name);
2062 gpiochip_free_own_desc(desc);
2066 /* Mark GPIO as hogged so it can be identified and removed later */
2067 set_bit(FLAG_IS_HOGGED, &desc->flags);
2069 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2070 desc_to_gpio(desc), name,
2071 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2072 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2073 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2079 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2080 * @chip: gpio chip to act on
2082 * This is only used by of_gpiochip_remove to free hogged gpios
2084 static void gpiochip_free_hogs(struct gpio_chip *chip)
2088 for (id = 0; id < chip->ngpio; id++) {
2089 if (test_bit(FLAG_IS_HOGGED, &chip->desc[id].flags))
2090 gpiochip_free_own_desc(&chip->desc[id]);
2095 * gpiod_put - dispose of a GPIO descriptor
2096 * @desc: GPIO descriptor to dispose of
2098 * No descriptor can be used after gpiod_put() has been called on it.
2100 void gpiod_put(struct gpio_desc *desc)
2104 EXPORT_SYMBOL_GPL(gpiod_put);
2106 #ifdef CONFIG_DEBUG_FS
2108 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2111 unsigned gpio = chip->base;
2112 struct gpio_desc *gdesc = &chip->desc[0];
2116 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2117 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
2120 gpiod_get_direction(gdesc);
2121 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2122 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2123 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
2125 is_out ? "out" : "in ",
2127 ? (chip->get(chip, i) ? "hi" : "lo")
2129 is_irq ? "IRQ" : " ");
2130 seq_printf(s, "\n");
2134 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2136 unsigned long flags;
2137 struct gpio_chip *chip = NULL;
2138 loff_t index = *pos;
2142 spin_lock_irqsave(&gpio_lock, flags);
2143 list_for_each_entry(chip, &gpio_chips, list)
2145 spin_unlock_irqrestore(&gpio_lock, flags);
2148 spin_unlock_irqrestore(&gpio_lock, flags);
2153 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2155 unsigned long flags;
2156 struct gpio_chip *chip = v;
2159 spin_lock_irqsave(&gpio_lock, flags);
2160 if (list_is_last(&chip->list, &gpio_chips))
2163 ret = list_entry(chip->list.next, struct gpio_chip, list);
2164 spin_unlock_irqrestore(&gpio_lock, flags);
2172 static void gpiolib_seq_stop(struct seq_file *s, void *v)
2176 static int gpiolib_seq_show(struct seq_file *s, void *v)
2178 struct gpio_chip *chip = v;
2181 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2182 chip->base, chip->base + chip->ngpio - 1);
2185 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2188 seq_printf(s, ", %s", chip->label);
2189 if (chip->can_sleep)
2190 seq_printf(s, ", can sleep");
2191 seq_printf(s, ":\n");
2194 chip->dbg_show(s, chip);
2196 gpiolib_dbg_show(s, chip);
2201 static const struct seq_operations gpiolib_seq_ops = {
2202 .start = gpiolib_seq_start,
2203 .next = gpiolib_seq_next,
2204 .stop = gpiolib_seq_stop,
2205 .show = gpiolib_seq_show,
2208 static int gpiolib_open(struct inode *inode, struct file *file)
2210 return seq_open(file, &gpiolib_seq_ops);
2213 static const struct file_operations gpiolib_operations = {
2214 .owner = THIS_MODULE,
2215 .open = gpiolib_open,
2217 .llseek = seq_lseek,
2218 .release = seq_release,
2221 static int __init gpiolib_debugfs_init(void)
2223 /* /sys/kernel/debug/gpio */
2224 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2225 NULL, NULL, &gpiolib_operations);
2228 subsys_initcall(gpiolib_debugfs_init);
2230 #endif /* DEBUG_FS */