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);
57 static void gpiochip_free_hogs(struct gpio_chip *chip);
58 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
61 static inline void desc_set_label(struct gpio_desc *d, const char *label)
67 * Convert a GPIO number to its descriptor
69 struct gpio_desc *gpio_to_desc(unsigned gpio)
71 struct gpio_chip *chip;
74 spin_lock_irqsave(&gpio_lock, flags);
76 list_for_each_entry(chip, &gpio_chips, list) {
77 if (chip->base <= gpio && chip->base + chip->ngpio > gpio) {
78 spin_unlock_irqrestore(&gpio_lock, flags);
79 return &chip->desc[gpio - chip->base];
83 spin_unlock_irqrestore(&gpio_lock, flags);
85 if (!gpio_is_valid(gpio))
86 WARN(1, "invalid GPIO %d\n", gpio);
90 EXPORT_SYMBOL_GPL(gpio_to_desc);
93 * Get the GPIO descriptor corresponding to the given hw number for this chip.
95 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
98 if (hwnum >= chip->ngpio)
99 return ERR_PTR(-EINVAL);
101 return &chip->desc[hwnum];
105 * Convert a GPIO descriptor to the integer namespace.
106 * This should disappear in the future but is needed since we still
107 * use GPIO numbers for error messages and sysfs nodes
109 int desc_to_gpio(const struct gpio_desc *desc)
111 return desc->chip->base + (desc - &desc->chip->desc[0]);
113 EXPORT_SYMBOL_GPL(desc_to_gpio);
117 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
118 * @desc: descriptor to return the chip of
120 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
122 return desc ? desc->chip : NULL;
124 EXPORT_SYMBOL_GPL(gpiod_to_chip);
126 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
127 static int gpiochip_find_base(int ngpio)
129 struct gpio_chip *chip;
130 int base = ARCH_NR_GPIOS - ngpio;
132 list_for_each_entry_reverse(chip, &gpio_chips, list) {
133 /* found a free space? */
134 if (chip->base + chip->ngpio <= base)
137 /* nope, check the space right before the chip */
138 base = chip->base - ngpio;
141 if (gpio_is_valid(base)) {
142 pr_debug("%s: found new base at %d\n", __func__, base);
145 pr_err("%s: cannot find free range\n", __func__);
151 * gpiod_get_direction - return the current direction of a GPIO
152 * @desc: GPIO to get the direction of
154 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
156 * This function may sleep if gpiod_cansleep() is true.
158 int gpiod_get_direction(struct gpio_desc *desc)
160 struct gpio_chip *chip;
162 int status = -EINVAL;
164 chip = gpiod_to_chip(desc);
165 offset = gpio_chip_hwgpio(desc);
167 if (!chip->get_direction)
170 status = chip->get_direction(chip, offset);
172 /* GPIOF_DIR_IN, or other positive */
174 clear_bit(FLAG_IS_OUT, &desc->flags);
178 set_bit(FLAG_IS_OUT, &desc->flags);
182 EXPORT_SYMBOL_GPL(gpiod_get_direction);
185 * Add a new chip to the global chips list, keeping the list of chips sorted
188 * Return -EBUSY if the new chip overlaps with some other chip's integer
191 static int gpiochip_add_to_list(struct gpio_chip *chip)
193 struct list_head *pos;
194 struct gpio_chip *_chip;
197 /* find where to insert our chip */
198 list_for_each(pos, &gpio_chips) {
199 _chip = list_entry(pos, struct gpio_chip, list);
200 /* shall we insert before _chip? */
201 if (_chip->base >= chip->base + chip->ngpio)
205 /* are we stepping on the chip right before? */
206 if (pos != &gpio_chips && pos->prev != &gpio_chips) {
207 _chip = list_entry(pos->prev, struct gpio_chip, list);
208 if (_chip->base + _chip->ngpio > chip->base) {
210 "GPIO integer space overlap, cannot add chip\n");
216 list_add_tail(&chip->list, pos);
222 * gpiochip_add() - register a gpio_chip
223 * @chip: the chip to register, with chip->base initialized
224 * Context: potentially before irqs will work
226 * Returns a negative errno if the chip can't be registered, such as
227 * because the chip->base is invalid or already associated with a
228 * different chip. Otherwise it returns zero as a success code.
230 * When gpiochip_add() is called very early during boot, so that GPIOs
231 * can be freely used, the chip->dev device must be registered before
232 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
233 * for GPIOs will fail rudely.
235 * If chip->base is negative, this requests dynamic assignment of
236 * a range of valid GPIOs.
238 int gpiochip_add(struct gpio_chip *chip)
243 int base = chip->base;
244 struct gpio_desc *descs;
246 descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL);
250 spin_lock_irqsave(&gpio_lock, flags);
253 base = gpiochip_find_base(chip->ngpio);
256 spin_unlock_irqrestore(&gpio_lock, flags);
262 status = gpiochip_add_to_list(chip);
264 spin_unlock_irqrestore(&gpio_lock, flags);
268 for (id = 0; id < chip->ngpio; id++) {
269 struct gpio_desc *desc = &descs[id];
273 /* REVISIT: most hardware initializes GPIOs as inputs (often
274 * with pullups enabled) so power usage is minimized. Linux
275 * code should set the gpio direction first thing; but until
276 * it does, and in case chip->get_direction is not set, we may
277 * expose the wrong direction in sysfs.
279 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
284 spin_unlock_irqrestore(&gpio_lock, flags);
286 #ifdef CONFIG_PINCTRL
287 INIT_LIST_HEAD(&chip->pin_ranges);
290 if (!chip->owner && chip->dev && chip->dev->driver)
291 chip->owner = chip->dev->driver->owner;
293 of_gpiochip_add(chip);
294 acpi_gpiochip_add(chip);
296 status = gpiochip_sysfs_register(chip);
298 goto err_remove_chip;
300 pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
301 chip->base, chip->base + chip->ngpio - 1,
302 chip->label ? : "generic");
307 acpi_gpiochip_remove(chip);
308 gpiochip_free_hogs(chip);
309 of_gpiochip_remove(chip);
310 spin_lock_irqsave(&gpio_lock, flags);
311 list_del(&chip->list);
312 spin_unlock_irqrestore(&gpio_lock, flags);
317 /* failures here can mean systems won't boot... */
318 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
319 chip->base, chip->base + chip->ngpio - 1,
320 chip->label ? : "generic");
323 EXPORT_SYMBOL_GPL(gpiochip_add);
326 * gpiochip_remove() - unregister a gpio_chip
327 * @chip: the chip to unregister
329 * A gpio_chip with any GPIOs still requested may not be removed.
331 void gpiochip_remove(struct gpio_chip *chip)
333 struct gpio_desc *desc;
336 bool requested = false;
338 gpiochip_sysfs_unregister(chip);
340 gpiochip_irqchip_remove(chip);
342 acpi_gpiochip_remove(chip);
343 gpiochip_remove_pin_ranges(chip);
344 gpiochip_free_hogs(chip);
345 of_gpiochip_remove(chip);
347 spin_lock_irqsave(&gpio_lock, flags);
348 for (id = 0; id < chip->ngpio; id++) {
349 desc = &chip->desc[id];
351 if (test_bit(FLAG_REQUESTED, &desc->flags))
354 list_del(&chip->list);
355 spin_unlock_irqrestore(&gpio_lock, flags);
358 dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
363 EXPORT_SYMBOL_GPL(gpiochip_remove);
366 * gpiochip_find() - iterator for locating a specific gpio_chip
367 * @data: data to pass to match function
368 * @callback: Callback function to check gpio_chip
370 * Similar to bus_find_device. It returns a reference to a gpio_chip as
371 * determined by a user supplied @match callback. The callback should return
372 * 0 if the device doesn't match and non-zero if it does. If the callback is
373 * non-zero, this function will return to the caller and not iterate over any
376 struct gpio_chip *gpiochip_find(void *data,
377 int (*match)(struct gpio_chip *chip,
380 struct gpio_chip *chip;
383 spin_lock_irqsave(&gpio_lock, flags);
384 list_for_each_entry(chip, &gpio_chips, list)
385 if (match(chip, data))
389 if (&chip->list == &gpio_chips)
391 spin_unlock_irqrestore(&gpio_lock, flags);
395 EXPORT_SYMBOL_GPL(gpiochip_find);
397 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
399 const char *name = data;
401 return !strcmp(chip->label, name);
404 static struct gpio_chip *find_chip_by_name(const char *name)
406 return gpiochip_find((void *)name, gpiochip_match_name);
409 #ifdef CONFIG_GPIOLIB_IRQCHIP
412 * The following is irqchip helper code for gpiochips.
416 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
417 * @gpiochip: the gpiochip to set the irqchip chain to
418 * @irqchip: the irqchip to chain to the gpiochip
419 * @parent_irq: the irq number corresponding to the parent IRQ for this
421 * @parent_handler: the parent interrupt handler for the accumulated IRQ
422 * coming out of the gpiochip. If the interrupt is nested rather than
423 * cascaded, pass NULL in this handler argument
425 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
426 struct irq_chip *irqchip,
428 irq_flow_handler_t parent_handler)
432 if (!gpiochip->irqdomain) {
433 chip_err(gpiochip, "called %s before setting up irqchip\n",
438 if (parent_handler) {
439 if (gpiochip->can_sleep) {
441 "you cannot have chained interrupts on a "
442 "chip that may sleep\n");
446 * The parent irqchip is already using the chip_data for this
447 * irqchip, so our callbacks simply use the handler_data.
449 irq_set_chained_handler_and_data(parent_irq, parent_handler,
452 gpiochip->irq_parent = parent_irq;
455 /* Set the parent IRQ for all affected IRQs */
456 for (offset = 0; offset < gpiochip->ngpio; offset++)
457 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
460 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
463 * This lock class tells lockdep that GPIO irqs are in a different
464 * category than their parents, so it won't report false recursion.
466 static struct lock_class_key gpiochip_irq_lock_class;
469 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
470 * @d: the irqdomain used by this irqchip
471 * @irq: the global irq number used by this GPIO irqchip irq
472 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
474 * This function will set up the mapping for a certain IRQ line on a
475 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
476 * stored inside the gpiochip.
478 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
479 irq_hw_number_t hwirq)
481 struct gpio_chip *chip = d->host_data;
483 irq_set_chip_data(irq, chip);
484 irq_set_lockdep_class(irq, &gpiochip_irq_lock_class);
485 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
486 /* Chips that can sleep need nested thread handlers */
487 if (chip->can_sleep && !chip->irq_not_threaded)
488 irq_set_nested_thread(irq, 1);
489 irq_set_noprobe(irq);
492 * No set-up of the hardware will happen if IRQ_TYPE_NONE
493 * is passed as default type.
495 if (chip->irq_default_type != IRQ_TYPE_NONE)
496 irq_set_irq_type(irq, chip->irq_default_type);
501 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
503 struct gpio_chip *chip = d->host_data;
506 irq_set_nested_thread(irq, 0);
507 irq_set_chip_and_handler(irq, NULL, NULL);
508 irq_set_chip_data(irq, NULL);
511 static const struct irq_domain_ops gpiochip_domain_ops = {
512 .map = gpiochip_irq_map,
513 .unmap = gpiochip_irq_unmap,
514 /* Virtually all GPIO irqchips are twocell:ed */
515 .xlate = irq_domain_xlate_twocell,
518 static int gpiochip_irq_reqres(struct irq_data *d)
520 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
522 if (!try_module_get(chip->owner))
525 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
527 "unable to lock HW IRQ %lu for IRQ\n",
529 module_put(chip->owner);
535 static void gpiochip_irq_relres(struct irq_data *d)
537 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
539 gpiochip_unlock_as_irq(chip, d->hwirq);
540 module_put(chip->owner);
543 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
545 return irq_find_mapping(chip->irqdomain, offset);
549 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
550 * @gpiochip: the gpiochip to remove the irqchip from
552 * This is called only from gpiochip_remove()
554 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
558 acpi_gpiochip_free_interrupts(gpiochip);
560 if (gpiochip->irq_parent) {
561 irq_set_chained_handler(gpiochip->irq_parent, NULL);
562 irq_set_handler_data(gpiochip->irq_parent, NULL);
565 /* Remove all IRQ mappings and delete the domain */
566 if (gpiochip->irqdomain) {
567 for (offset = 0; offset < gpiochip->ngpio; offset++)
569 irq_find_mapping(gpiochip->irqdomain, offset));
570 irq_domain_remove(gpiochip->irqdomain);
573 if (gpiochip->irqchip) {
574 gpiochip->irqchip->irq_request_resources = NULL;
575 gpiochip->irqchip->irq_release_resources = NULL;
576 gpiochip->irqchip = NULL;
581 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
582 * @gpiochip: the gpiochip to add the irqchip to
583 * @irqchip: the irqchip to add to the gpiochip
584 * @first_irq: if not dynamically assigned, the base (first) IRQ to
585 * allocate gpiochip irqs from
586 * @handler: the irq handler to use (often a predefined irq core function)
587 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
588 * to have the core avoid setting up any default type in the hardware.
590 * This function closely associates a certain irqchip with a certain
591 * gpiochip, providing an irq domain to translate the local IRQs to
592 * global irqs in the gpiolib core, and making sure that the gpiochip
593 * is passed as chip data to all related functions. Driver callbacks
594 * need to use container_of() to get their local state containers back
595 * from the gpiochip passed as chip data. An irqdomain will be stored
596 * in the gpiochip that shall be used by the driver to handle IRQ number
597 * translation. The gpiochip will need to be initialized and registered
598 * before calling this function.
600 * This function will handle two cell:ed simple IRQs and assumes all
601 * the pins on the gpiochip can generate a unique IRQ. Everything else
602 * need to be open coded.
604 int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
605 struct irq_chip *irqchip,
606 unsigned int first_irq,
607 irq_flow_handler_t handler,
610 struct device_node *of_node;
612 unsigned irq_base = 0;
614 if (!gpiochip || !irqchip)
617 if (!gpiochip->dev) {
618 pr_err("missing gpiochip .dev parent pointer\n");
621 of_node = gpiochip->dev->of_node;
622 #ifdef CONFIG_OF_GPIO
624 * If the gpiochip has an assigned OF node this takes precedence
625 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
627 if (gpiochip->of_node)
628 of_node = gpiochip->of_node;
630 gpiochip->irqchip = irqchip;
631 gpiochip->irq_handler = handler;
632 gpiochip->irq_default_type = type;
633 gpiochip->to_irq = gpiochip_to_irq;
634 gpiochip->irqdomain = irq_domain_add_simple(of_node,
635 gpiochip->ngpio, first_irq,
636 &gpiochip_domain_ops, gpiochip);
637 if (!gpiochip->irqdomain) {
638 gpiochip->irqchip = NULL;
641 irqchip->irq_request_resources = gpiochip_irq_reqres;
642 irqchip->irq_release_resources = gpiochip_irq_relres;
645 * Prepare the mapping since the irqchip shall be orthogonal to
646 * any gpiochip calls. If the first_irq was zero, this is
647 * necessary to allocate descriptors for all IRQs.
649 for (offset = 0; offset < gpiochip->ngpio; offset++) {
650 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
653 * Store the base into the gpiochip to be used when
654 * unmapping the irqs.
656 gpiochip->irq_base = irq_base;
659 acpi_gpiochip_request_interrupts(gpiochip);
663 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
665 #else /* CONFIG_GPIOLIB_IRQCHIP */
667 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
669 #endif /* CONFIG_GPIOLIB_IRQCHIP */
671 #ifdef CONFIG_PINCTRL
674 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
675 * @chip: the gpiochip to add the range for
676 * @pctldev: the pin controller to map to
677 * @gpio_offset: the start offset in the current gpio_chip number space
678 * @pin_group: name of the pin group inside the pin controller
680 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
681 struct pinctrl_dev *pctldev,
682 unsigned int gpio_offset, const char *pin_group)
684 struct gpio_pin_range *pin_range;
687 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
689 chip_err(chip, "failed to allocate pin ranges\n");
693 /* Use local offset as range ID */
694 pin_range->range.id = gpio_offset;
695 pin_range->range.gc = chip;
696 pin_range->range.name = chip->label;
697 pin_range->range.base = chip->base + gpio_offset;
698 pin_range->pctldev = pctldev;
700 ret = pinctrl_get_group_pins(pctldev, pin_group,
701 &pin_range->range.pins,
702 &pin_range->range.npins);
708 pinctrl_add_gpio_range(pctldev, &pin_range->range);
710 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
711 gpio_offset, gpio_offset + pin_range->range.npins - 1,
712 pinctrl_dev_get_devname(pctldev), pin_group);
714 list_add_tail(&pin_range->node, &chip->pin_ranges);
718 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
721 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
722 * @chip: the gpiochip to add the range for
723 * @pinctrl_name: the dev_name() of the pin controller to map to
724 * @gpio_offset: the start offset in the current gpio_chip number space
725 * @pin_offset: the start offset in the pin controller number space
726 * @npins: the number of pins from the offset of each pin space (GPIO and
727 * pin controller) to accumulate in this range
729 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
730 unsigned int gpio_offset, unsigned int pin_offset,
733 struct gpio_pin_range *pin_range;
736 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
738 chip_err(chip, "failed to allocate pin ranges\n");
742 /* Use local offset as range ID */
743 pin_range->range.id = gpio_offset;
744 pin_range->range.gc = chip;
745 pin_range->range.name = chip->label;
746 pin_range->range.base = chip->base + gpio_offset;
747 pin_range->range.pin_base = pin_offset;
748 pin_range->range.npins = npins;
749 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
751 if (IS_ERR(pin_range->pctldev)) {
752 ret = PTR_ERR(pin_range->pctldev);
753 chip_err(chip, "could not create pin range\n");
757 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
758 gpio_offset, gpio_offset + npins - 1,
760 pin_offset, pin_offset + npins - 1);
762 list_add_tail(&pin_range->node, &chip->pin_ranges);
766 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
769 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
770 * @chip: the chip to remove all the mappings for
772 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
774 struct gpio_pin_range *pin_range, *tmp;
776 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
777 list_del(&pin_range->node);
778 pinctrl_remove_gpio_range(pin_range->pctldev,
783 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
785 #endif /* CONFIG_PINCTRL */
787 /* These "optional" allocation calls help prevent drivers from stomping
788 * on each other, and help provide better diagnostics in debugfs.
789 * They're called even less than the "set direction" calls.
791 static int __gpiod_request(struct gpio_desc *desc, const char *label)
793 struct gpio_chip *chip = desc->chip;
797 spin_lock_irqsave(&gpio_lock, flags);
799 /* NOTE: gpio_request() can be called in early boot,
800 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
803 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
804 desc_set_label(desc, label ? : "?");
812 /* chip->request may sleep */
813 spin_unlock_irqrestore(&gpio_lock, flags);
814 status = chip->request(chip, gpio_chip_hwgpio(desc));
815 spin_lock_irqsave(&gpio_lock, flags);
818 desc_set_label(desc, NULL);
819 clear_bit(FLAG_REQUESTED, &desc->flags);
823 if (chip->get_direction) {
824 /* chip->get_direction may sleep */
825 spin_unlock_irqrestore(&gpio_lock, flags);
826 gpiod_get_direction(desc);
827 spin_lock_irqsave(&gpio_lock, flags);
830 spin_unlock_irqrestore(&gpio_lock, flags);
834 int gpiod_request(struct gpio_desc *desc, const char *label)
836 int status = -EPROBE_DEFER;
837 struct gpio_chip *chip;
840 pr_warn("%s: invalid GPIO\n", __func__);
848 if (try_module_get(chip->owner)) {
849 status = __gpiod_request(desc, label);
851 module_put(chip->owner);
856 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
861 static bool __gpiod_free(struct gpio_desc *desc)
865 struct gpio_chip *chip;
869 gpiod_unexport(desc);
871 spin_lock_irqsave(&gpio_lock, flags);
874 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
876 spin_unlock_irqrestore(&gpio_lock, flags);
877 might_sleep_if(chip->can_sleep);
878 chip->free(chip, gpio_chip_hwgpio(desc));
879 spin_lock_irqsave(&gpio_lock, flags);
881 desc_set_label(desc, NULL);
882 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
883 clear_bit(FLAG_REQUESTED, &desc->flags);
884 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
885 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
886 clear_bit(FLAG_IS_HOGGED, &desc->flags);
890 spin_unlock_irqrestore(&gpio_lock, flags);
894 void gpiod_free(struct gpio_desc *desc)
896 if (desc && __gpiod_free(desc))
897 module_put(desc->chip->owner);
899 WARN_ON(extra_checks);
903 * gpiochip_is_requested - return string iff signal was requested
904 * @chip: controller managing the signal
905 * @offset: of signal within controller's 0..(ngpio - 1) range
907 * Returns NULL if the GPIO is not currently requested, else a string.
908 * The string returned is the label passed to gpio_request(); if none has been
909 * passed it is a meaningless, non-NULL constant.
911 * This function is for use by GPIO controller drivers. The label can
912 * help with diagnostics, and knowing that the signal is used as a GPIO
913 * can help avoid accidentally multiplexing it to another controller.
915 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
917 struct gpio_desc *desc;
919 if (!GPIO_OFFSET_VALID(chip, offset))
922 desc = &chip->desc[offset];
924 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
928 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
931 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
932 * @desc: GPIO descriptor to request
933 * @label: label for the GPIO
935 * Function allows GPIO chip drivers to request and use their own GPIO
936 * descriptors via gpiolib API. Difference to gpiod_request() is that this
937 * function will not increase reference count of the GPIO chip module. This
938 * allows the GPIO chip module to be unloaded as needed (we assume that the
939 * GPIO chip driver handles freeing the GPIOs it has requested).
941 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
944 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
948 chip_err(chip, "failed to get GPIO descriptor\n");
952 err = __gpiod_request(desc, label);
958 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
961 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
962 * @desc: GPIO descriptor to free
964 * Function frees the given GPIO requested previously with
965 * gpiochip_request_own_desc().
967 void gpiochip_free_own_desc(struct gpio_desc *desc)
972 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
974 /* Drivers MUST set GPIO direction before making get/set calls. In
975 * some cases this is done in early boot, before IRQs are enabled.
977 * As a rule these aren't called more than once (except for drivers
978 * using the open-drain emulation idiom) so these are natural places
979 * to accumulate extra debugging checks. Note that we can't (yet)
980 * rely on gpio_request() having been called beforehand.
984 * gpiod_direction_input - set the GPIO direction to input
985 * @desc: GPIO to set to input
987 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
988 * be called safely on it.
990 * Return 0 in case of success, else an error code.
992 int gpiod_direction_input(struct gpio_desc *desc)
994 struct gpio_chip *chip;
995 int status = -EINVAL;
997 if (!desc || !desc->chip) {
998 pr_warn("%s: invalid GPIO\n", __func__);
1003 if (!chip->get || !chip->direction_input) {
1005 "%s: missing get() or direction_input() operations\n",
1010 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1012 clear_bit(FLAG_IS_OUT, &desc->flags);
1014 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1018 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1020 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1022 struct gpio_chip *chip;
1023 int status = -EINVAL;
1025 /* GPIOs used for IRQs shall not be set as output */
1026 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1028 "%s: tried to set a GPIO tied to an IRQ as output\n",
1033 /* Open drain pin should not be driven to 1 */
1034 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1035 return gpiod_direction_input(desc);
1037 /* Open source pin should not be driven to 0 */
1038 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1039 return gpiod_direction_input(desc);
1042 if (!chip->set || !chip->direction_output) {
1044 "%s: missing set() or direction_output() operations\n",
1049 status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
1051 set_bit(FLAG_IS_OUT, &desc->flags);
1052 trace_gpio_value(desc_to_gpio(desc), 0, value);
1053 trace_gpio_direction(desc_to_gpio(desc), 0, status);
1058 * gpiod_direction_output_raw - set the GPIO direction to output
1059 * @desc: GPIO to set to output
1060 * @value: initial output value of the GPIO
1062 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1063 * be called safely on it. The initial value of the output must be specified
1064 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1066 * Return 0 in case of success, else an error code.
1068 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1070 if (!desc || !desc->chip) {
1071 pr_warn("%s: invalid GPIO\n", __func__);
1074 return _gpiod_direction_output_raw(desc, value);
1076 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1079 * gpiod_direction_output - set the GPIO direction to output
1080 * @desc: GPIO to set to output
1081 * @value: initial output value of the GPIO
1083 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1084 * be called safely on it. The initial value of the output must be specified
1085 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1088 * Return 0 in case of success, else an error code.
1090 int gpiod_direction_output(struct gpio_desc *desc, int value)
1092 if (!desc || !desc->chip) {
1093 pr_warn("%s: invalid GPIO\n", __func__);
1096 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1098 return _gpiod_direction_output_raw(desc, value);
1100 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1103 * gpiod_set_debounce - sets @debounce time for a @gpio
1104 * @gpio: the gpio to set debounce time
1105 * @debounce: debounce time is microseconds
1107 * returns -ENOTSUPP if the controller does not support setting
1110 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1112 struct gpio_chip *chip;
1114 if (!desc || !desc->chip) {
1115 pr_warn("%s: invalid GPIO\n", __func__);
1120 if (!chip->set || !chip->set_debounce) {
1122 "%s: missing set() or set_debounce() operations\n",
1127 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1129 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1132 * gpiod_is_active_low - test whether a GPIO is active-low or not
1133 * @desc: the gpio descriptor to test
1135 * Returns 1 if the GPIO is active-low, 0 otherwise.
1137 int gpiod_is_active_low(const struct gpio_desc *desc)
1139 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1141 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1143 /* I/O calls are only valid after configuration completed; the relevant
1144 * "is this a valid GPIO" error checks should already have been done.
1146 * "Get" operations are often inlinable as reading a pin value register,
1147 * and masking the relevant bit in that register.
1149 * When "set" operations are inlinable, they involve writing that mask to
1150 * one register to set a low value, or a different register to set it high.
1151 * Otherwise locking is needed, so there may be little value to inlining.
1153 *------------------------------------------------------------------------
1155 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1156 * have requested the GPIO. That can include implicit requesting by
1157 * a direction setting call. Marking a gpio as requested locks its chip
1158 * in memory, guaranteeing that these table lookups need no more locking
1159 * and that gpiochip_remove() will fail.
1161 * REVISIT when debugging, consider adding some instrumentation to ensure
1162 * that the GPIO was actually requested.
1165 static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
1167 struct gpio_chip *chip;
1172 offset = gpio_chip_hwgpio(desc);
1173 value = chip->get ? chip->get(chip, offset) : false;
1174 trace_gpio_value(desc_to_gpio(desc), 1, value);
1179 * gpiod_get_raw_value() - return a gpio's raw value
1180 * @desc: gpio whose value will be returned
1182 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1183 * its ACTIVE_LOW status.
1185 * This function should be called from contexts where we cannot sleep, and will
1186 * complain if the GPIO chip functions potentially sleep.
1188 int gpiod_get_raw_value(const struct gpio_desc *desc)
1192 /* Should be using gpio_get_value_cansleep() */
1193 WARN_ON(desc->chip->can_sleep);
1194 return _gpiod_get_raw_value(desc);
1196 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1199 * gpiod_get_value() - return a gpio's value
1200 * @desc: gpio whose value will be returned
1202 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1205 * This function should be called from contexts where we cannot sleep, and will
1206 * complain if the GPIO chip functions potentially sleep.
1208 int gpiod_get_value(const struct gpio_desc *desc)
1213 /* Should be using gpio_get_value_cansleep() */
1214 WARN_ON(desc->chip->can_sleep);
1216 value = _gpiod_get_raw_value(desc);
1217 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1222 EXPORT_SYMBOL_GPL(gpiod_get_value);
1225 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1226 * @desc: gpio descriptor whose state need to be set.
1227 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1229 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1232 struct gpio_chip *chip = desc->chip;
1233 int offset = gpio_chip_hwgpio(desc);
1236 err = chip->direction_input(chip, offset);
1238 clear_bit(FLAG_IS_OUT, &desc->flags);
1240 err = chip->direction_output(chip, offset, 0);
1242 set_bit(FLAG_IS_OUT, &desc->flags);
1244 trace_gpio_direction(desc_to_gpio(desc), value, err);
1247 "%s: Error in set_value for open drain err %d\n",
1252 * _gpio_set_open_source_value() - Set the open source gpio's value.
1253 * @desc: gpio descriptor whose state need to be set.
1254 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1256 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1259 struct gpio_chip *chip = desc->chip;
1260 int offset = gpio_chip_hwgpio(desc);
1263 err = chip->direction_output(chip, offset, 1);
1265 set_bit(FLAG_IS_OUT, &desc->flags);
1267 err = chip->direction_input(chip, offset);
1269 clear_bit(FLAG_IS_OUT, &desc->flags);
1271 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1274 "%s: Error in set_value for open source err %d\n",
1278 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1280 struct gpio_chip *chip;
1283 trace_gpio_value(desc_to_gpio(desc), 0, value);
1284 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1285 _gpio_set_open_drain_value(desc, value);
1286 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1287 _gpio_set_open_source_value(desc, value);
1289 chip->set(chip, gpio_chip_hwgpio(desc), value);
1293 * set multiple outputs on the same chip;
1294 * use the chip's set_multiple function if available;
1295 * otherwise set the outputs sequentially;
1296 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1297 * defines which outputs are to be changed
1298 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1299 * defines the values the outputs specified by mask are to be set to
1301 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1302 unsigned long *mask, unsigned long *bits)
1304 if (chip->set_multiple) {
1305 chip->set_multiple(chip, mask, bits);
1308 for (i = 0; i < chip->ngpio; i++) {
1309 if (mask[BIT_WORD(i)] == 0) {
1310 /* no more set bits in this mask word;
1311 * skip ahead to the next word */
1312 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1315 /* set outputs if the corresponding mask bit is set */
1316 if (__test_and_clear_bit(i, mask))
1317 chip->set(chip, i, test_bit(i, bits));
1322 static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
1323 unsigned int array_size,
1324 struct gpio_desc **desc_array,
1329 while (i < array_size) {
1330 struct gpio_chip *chip = desc_array[i]->chip;
1331 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1332 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1336 WARN_ON(chip->can_sleep);
1338 memset(mask, 0, sizeof(mask));
1340 struct gpio_desc *desc = desc_array[i];
1341 int hwgpio = gpio_chip_hwgpio(desc);
1342 int value = value_array[i];
1344 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1346 trace_gpio_value(desc_to_gpio(desc), 0, value);
1348 * collect all normal outputs belonging to the same chip
1349 * open drain and open source outputs are set individually
1351 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1352 _gpio_set_open_drain_value(desc, value);
1353 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1354 _gpio_set_open_source_value(desc, value);
1356 __set_bit(hwgpio, mask);
1358 __set_bit(hwgpio, bits);
1360 __clear_bit(hwgpio, bits);
1364 } while ((i < array_size) && (desc_array[i]->chip == chip));
1365 /* push collected bits to outputs */
1367 gpio_chip_set_multiple(chip, mask, bits);
1372 * gpiod_set_raw_value() - assign a gpio's raw value
1373 * @desc: gpio whose value will be assigned
1374 * @value: value to assign
1376 * Set the raw value of the GPIO, i.e. the value of its physical line without
1377 * regard for its ACTIVE_LOW status.
1379 * This function should be called from contexts where we cannot sleep, and will
1380 * complain if the GPIO chip functions potentially sleep.
1382 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1386 /* Should be using gpio_set_value_cansleep() */
1387 WARN_ON(desc->chip->can_sleep);
1388 _gpiod_set_raw_value(desc, value);
1390 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1393 * gpiod_set_value() - assign a gpio's value
1394 * @desc: gpio whose value will be assigned
1395 * @value: value to assign
1397 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1400 * This function should be called from contexts where we cannot sleep, and will
1401 * complain if the GPIO chip functions potentially sleep.
1403 void gpiod_set_value(struct gpio_desc *desc, int value)
1407 /* Should be using gpio_set_value_cansleep() */
1408 WARN_ON(desc->chip->can_sleep);
1409 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1411 _gpiod_set_raw_value(desc, value);
1413 EXPORT_SYMBOL_GPL(gpiod_set_value);
1416 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1417 * @array_size: number of elements in the descriptor / value arrays
1418 * @desc_array: array of GPIO descriptors whose values will be assigned
1419 * @value_array: array of values to assign
1421 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1422 * without regard for their ACTIVE_LOW status.
1424 * This function should be called from contexts where we cannot sleep, and will
1425 * complain if the GPIO chip functions potentially sleep.
1427 void gpiod_set_raw_array_value(unsigned int array_size,
1428 struct gpio_desc **desc_array, int *value_array)
1432 gpiod_set_array_value_priv(true, false, array_size, desc_array,
1435 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
1438 * gpiod_set_array_value() - assign values to an array of GPIOs
1439 * @array_size: number of elements in the descriptor / value arrays
1440 * @desc_array: array of GPIO descriptors whose values will be assigned
1441 * @value_array: array of values to assign
1443 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1446 * This function should be called from contexts where we cannot sleep, and will
1447 * complain if the GPIO chip functions potentially sleep.
1449 void gpiod_set_array_value(unsigned int array_size,
1450 struct gpio_desc **desc_array, int *value_array)
1454 gpiod_set_array_value_priv(false, false, array_size, desc_array,
1457 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
1460 * gpiod_cansleep() - report whether gpio value access may sleep
1461 * @desc: gpio to check
1464 int gpiod_cansleep(const struct gpio_desc *desc)
1468 return desc->chip->can_sleep;
1470 EXPORT_SYMBOL_GPL(gpiod_cansleep);
1473 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1474 * @desc: gpio whose IRQ will be returned (already requested)
1476 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1479 int gpiod_to_irq(const struct gpio_desc *desc)
1481 struct gpio_chip *chip;
1487 offset = gpio_chip_hwgpio(desc);
1488 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
1490 EXPORT_SYMBOL_GPL(gpiod_to_irq);
1493 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1494 * @chip: the chip the GPIO to lock belongs to
1495 * @offset: the offset of the GPIO to lock as IRQ
1497 * This is used directly by GPIO drivers that want to lock down
1498 * a certain GPIO line to be used for IRQs.
1500 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
1502 if (offset >= chip->ngpio)
1505 if (test_bit(FLAG_IS_OUT, &chip->desc[offset].flags)) {
1507 "%s: tried to flag a GPIO set as output for IRQ\n",
1512 set_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1515 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
1518 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1519 * @chip: the chip the GPIO to lock belongs to
1520 * @offset: the offset of the GPIO to lock as IRQ
1522 * This is used directly by GPIO drivers that want to indicate
1523 * that a certain GPIO is no longer used exclusively for IRQ.
1525 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
1527 if (offset >= chip->ngpio)
1530 clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1532 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
1535 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1536 * @desc: gpio whose value will be returned
1538 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1539 * its ACTIVE_LOW status.
1541 * This function is to be called from contexts that can sleep.
1543 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
1545 might_sleep_if(extra_checks);
1548 return _gpiod_get_raw_value(desc);
1550 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
1553 * gpiod_get_value_cansleep() - return a gpio's value
1554 * @desc: gpio whose value will be returned
1556 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1559 * This function is to be called from contexts that can sleep.
1561 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
1565 might_sleep_if(extra_checks);
1569 value = _gpiod_get_raw_value(desc);
1570 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1575 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
1578 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
1579 * @desc: gpio whose value will be assigned
1580 * @value: value to assign
1582 * Set the raw value of the GPIO, i.e. the value of its physical line without
1583 * regard for its ACTIVE_LOW status.
1585 * This function is to be called from contexts that can sleep.
1587 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
1589 might_sleep_if(extra_checks);
1592 _gpiod_set_raw_value(desc, value);
1594 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
1597 * gpiod_set_value_cansleep() - assign a gpio's value
1598 * @desc: gpio whose value will be assigned
1599 * @value: value to assign
1601 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1604 * This function is to be called from contexts that can sleep.
1606 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
1608 might_sleep_if(extra_checks);
1612 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1614 _gpiod_set_raw_value(desc, value);
1616 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
1619 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
1620 * @array_size: number of elements in the descriptor / value arrays
1621 * @desc_array: array of GPIO descriptors whose values will be assigned
1622 * @value_array: array of values to assign
1624 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1625 * without regard for their ACTIVE_LOW status.
1627 * This function is to be called from contexts that can sleep.
1629 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
1630 struct gpio_desc **desc_array,
1633 might_sleep_if(extra_checks);
1636 gpiod_set_array_value_priv(true, true, array_size, desc_array,
1639 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
1642 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
1643 * @array_size: number of elements in the descriptor / value arrays
1644 * @desc_array: array of GPIO descriptors whose values will be assigned
1645 * @value_array: array of values to assign
1647 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1650 * This function is to be called from contexts that can sleep.
1652 void gpiod_set_array_value_cansleep(unsigned int array_size,
1653 struct gpio_desc **desc_array,
1656 might_sleep_if(extra_checks);
1659 gpiod_set_array_value_priv(false, true, array_size, desc_array,
1662 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
1665 * gpiod_add_lookup_table() - register GPIO device consumers
1666 * @table: table of consumers to register
1668 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
1670 mutex_lock(&gpio_lookup_lock);
1672 list_add_tail(&table->list, &gpio_lookup_list);
1674 mutex_unlock(&gpio_lookup_lock);
1677 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
1679 enum gpio_lookup_flags *flags)
1681 char prop_name[32]; /* 32 is max size of property name */
1682 enum of_gpio_flags of_flags;
1683 struct gpio_desc *desc;
1686 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1688 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
1691 snprintf(prop_name, sizeof(prop_name), "%s",
1694 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
1696 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1703 if (of_flags & OF_GPIO_ACTIVE_LOW)
1704 *flags |= GPIO_ACTIVE_LOW;
1709 static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
1711 enum gpio_lookup_flags *flags)
1713 struct acpi_device *adev = ACPI_COMPANION(dev);
1714 struct acpi_gpio_info info;
1715 struct gpio_desc *desc;
1719 /* Try first from _DSD */
1720 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1721 if (con_id && strcmp(con_id, "gpios")) {
1722 snprintf(propname, sizeof(propname), "%s-%s",
1723 con_id, gpio_suffixes[i]);
1725 snprintf(propname, sizeof(propname), "%s",
1729 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
1730 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1734 /* Then from plain _CRS GPIOs */
1736 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
1741 if (info.active_low)
1742 *flags |= GPIO_ACTIVE_LOW;
1747 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
1749 const char *dev_id = dev ? dev_name(dev) : NULL;
1750 struct gpiod_lookup_table *table;
1752 mutex_lock(&gpio_lookup_lock);
1754 list_for_each_entry(table, &gpio_lookup_list, list) {
1755 if (table->dev_id && dev_id) {
1757 * Valid strings on both ends, must be identical to have
1760 if (!strcmp(table->dev_id, dev_id))
1764 * One of the pointers is NULL, so both must be to have
1767 if (dev_id == table->dev_id)
1774 mutex_unlock(&gpio_lookup_lock);
1778 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
1780 enum gpio_lookup_flags *flags)
1782 struct gpio_desc *desc = ERR_PTR(-ENOENT);
1783 struct gpiod_lookup_table *table;
1784 struct gpiod_lookup *p;
1786 table = gpiod_find_lookup_table(dev);
1790 for (p = &table->table[0]; p->chip_label; p++) {
1791 struct gpio_chip *chip;
1793 /* idx must always match exactly */
1797 /* If the lookup entry has a con_id, require exact match */
1798 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
1801 chip = find_chip_by_name(p->chip_label);
1804 dev_err(dev, "cannot find GPIO chip %s\n",
1806 return ERR_PTR(-ENODEV);
1809 if (chip->ngpio <= p->chip_hwnum) {
1811 "requested GPIO %d is out of range [0..%d] for chip %s\n",
1812 idx, chip->ngpio, chip->label);
1813 return ERR_PTR(-EINVAL);
1816 desc = gpiochip_get_desc(chip, p->chip_hwnum);
1825 static int dt_gpio_count(struct device *dev, const char *con_id)
1831 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1833 snprintf(propname, sizeof(propname), "%s-%s",
1834 con_id, gpio_suffixes[i]);
1836 snprintf(propname, sizeof(propname), "%s",
1839 ret = of_gpio_named_count(dev->of_node, propname);
1846 static int platform_gpio_count(struct device *dev, const char *con_id)
1848 struct gpiod_lookup_table *table;
1849 struct gpiod_lookup *p;
1850 unsigned int count = 0;
1852 table = gpiod_find_lookup_table(dev);
1856 for (p = &table->table[0]; p->chip_label; p++) {
1857 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
1858 (!con_id && !p->con_id))
1868 * gpiod_count - return the number of GPIOs associated with a device / function
1869 * or -ENOENT if no GPIO has been assigned to the requested function
1870 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1871 * @con_id: function within the GPIO consumer
1873 int gpiod_count(struct device *dev, const char *con_id)
1875 int count = -ENOENT;
1877 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
1878 count = dt_gpio_count(dev, con_id);
1879 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
1880 count = acpi_gpio_count(dev, con_id);
1883 count = platform_gpio_count(dev, con_id);
1887 EXPORT_SYMBOL_GPL(gpiod_count);
1890 * gpiod_get - obtain a GPIO for a given GPIO function
1891 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1892 * @con_id: function within the GPIO consumer
1893 * @flags: optional GPIO initialization flags
1895 * Return the GPIO descriptor corresponding to the function con_id of device
1896 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
1897 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
1899 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
1900 enum gpiod_flags flags)
1902 return gpiod_get_index(dev, con_id, 0, flags);
1904 EXPORT_SYMBOL_GPL(gpiod_get);
1907 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
1908 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1909 * @con_id: function within the GPIO consumer
1910 * @flags: optional GPIO initialization flags
1912 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
1913 * the requested function it will return NULL. This is convenient for drivers
1914 * that need to handle optional GPIOs.
1916 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
1918 enum gpiod_flags flags)
1920 return gpiod_get_index_optional(dev, con_id, 0, flags);
1922 EXPORT_SYMBOL_GPL(gpiod_get_optional);
1926 * gpiod_configure_flags - helper function to configure a given GPIO
1927 * @desc: gpio whose value will be assigned
1928 * @con_id: function within the GPIO consumer
1929 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
1931 * @dflags: gpiod_flags - optional GPIO initialization flags
1933 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
1934 * requested function and/or index, or another IS_ERR() code if an error
1935 * occurred while trying to acquire the GPIO.
1937 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
1938 unsigned long lflags, enum gpiod_flags dflags)
1942 if (lflags & GPIO_ACTIVE_LOW)
1943 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
1944 if (lflags & GPIO_OPEN_DRAIN)
1945 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
1946 if (lflags & GPIO_OPEN_SOURCE)
1947 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
1949 /* No particular flag request, return here... */
1950 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
1951 pr_debug("no flags found for %s\n", con_id);
1956 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
1957 status = gpiod_direction_output(desc,
1958 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
1960 status = gpiod_direction_input(desc);
1966 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
1967 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1968 * @con_id: function within the GPIO consumer
1969 * @idx: index of the GPIO to obtain in the consumer
1970 * @flags: optional GPIO initialization flags
1972 * This variant of gpiod_get() allows to access GPIOs other than the first
1973 * defined one for functions that define several GPIOs.
1975 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
1976 * requested function and/or index, or another IS_ERR() code if an error
1977 * occurred while trying to acquire the GPIO.
1979 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
1982 enum gpiod_flags flags)
1984 struct gpio_desc *desc = NULL;
1986 enum gpio_lookup_flags lookupflags = 0;
1988 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
1991 /* Using device tree? */
1992 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
1993 dev_dbg(dev, "using device tree for GPIO lookup\n");
1994 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
1995 } else if (ACPI_COMPANION(dev)) {
1996 dev_dbg(dev, "using ACPI for GPIO lookup\n");
1997 desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
2002 * Either we are not using DT or ACPI, or their lookup did not return
2003 * a result. In that case, use platform lookup as a fallback.
2005 if (!desc || desc == ERR_PTR(-ENOENT)) {
2006 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2007 desc = gpiod_find(dev, con_id, idx, &lookupflags);
2011 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2015 status = gpiod_request(desc, con_id);
2017 return ERR_PTR(status);
2019 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
2021 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2023 return ERR_PTR(status);
2028 EXPORT_SYMBOL_GPL(gpiod_get_index);
2031 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2032 * @fwnode: handle of the firmware node
2033 * @propname: name of the firmware property representing the GPIO
2035 * This function can be used for drivers that get their configuration
2038 * Function properly finds the corresponding GPIO using whatever is the
2039 * underlying firmware interface and then makes sure that the GPIO
2040 * descriptor is requested before it is returned to the caller.
2042 * In case of error an ERR_PTR() is returned.
2044 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2045 const char *propname)
2047 struct gpio_desc *desc = ERR_PTR(-ENODEV);
2048 bool active_low = false;
2052 return ERR_PTR(-EINVAL);
2054 if (is_of_node(fwnode)) {
2055 enum of_gpio_flags flags;
2057 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2060 active_low = flags & OF_GPIO_ACTIVE_LOW;
2061 } else if (is_acpi_node(fwnode)) {
2062 struct acpi_gpio_info info;
2064 desc = acpi_get_gpiod_by_index(to_acpi_node(fwnode), propname, 0,
2067 active_low = info.active_low;
2073 ret = gpiod_request(desc, NULL);
2075 return ERR_PTR(ret);
2077 /* Only value flag can be set from both DT and ACPI is active_low */
2079 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2083 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2086 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2088 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2089 * @con_id: function within the GPIO consumer
2090 * @index: index of the GPIO to obtain in the consumer
2091 * @flags: optional GPIO initialization flags
2093 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2094 * specified index was assigned to the requested function it will return NULL.
2095 * This is convenient for drivers that need to handle optional GPIOs.
2097 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2100 enum gpiod_flags flags)
2102 struct gpio_desc *desc;
2104 desc = gpiod_get_index(dev, con_id, index, flags);
2106 if (PTR_ERR(desc) == -ENOENT)
2112 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2115 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2116 * @desc: gpio whose value will be assigned
2117 * @name: gpio line name
2118 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2120 * @dflags: gpiod_flags - optional GPIO initialization flags
2122 int gpiod_hog(struct gpio_desc *desc, const char *name,
2123 unsigned long lflags, enum gpiod_flags dflags)
2125 struct gpio_chip *chip;
2126 struct gpio_desc *local_desc;
2130 chip = gpiod_to_chip(desc);
2131 hwnum = gpio_chip_hwgpio(desc);
2133 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2134 if (IS_ERR(local_desc)) {
2135 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2136 name, chip->label, hwnum);
2137 return PTR_ERR(local_desc);
2140 status = gpiod_configure_flags(desc, name, lflags, dflags);
2142 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2143 name, chip->label, hwnum);
2144 gpiochip_free_own_desc(desc);
2148 /* Mark GPIO as hogged so it can be identified and removed later */
2149 set_bit(FLAG_IS_HOGGED, &desc->flags);
2151 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2152 desc_to_gpio(desc), name,
2153 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2154 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2155 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2161 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2162 * @chip: gpio chip to act on
2164 * This is only used by of_gpiochip_remove to free hogged gpios
2166 static void gpiochip_free_hogs(struct gpio_chip *chip)
2170 for (id = 0; id < chip->ngpio; id++) {
2171 if (test_bit(FLAG_IS_HOGGED, &chip->desc[id].flags))
2172 gpiochip_free_own_desc(&chip->desc[id]);
2177 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2178 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2179 * @con_id: function within the GPIO consumer
2180 * @flags: optional GPIO initialization flags
2182 * This function acquires all the GPIOs defined under a given function.
2184 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2185 * no GPIO has been assigned to the requested function, or another IS_ERR()
2186 * code if an error occurred while trying to acquire the GPIOs.
2188 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2190 enum gpiod_flags flags)
2192 struct gpio_desc *desc;
2193 struct gpio_descs *descs;
2196 count = gpiod_count(dev, con_id);
2198 return ERR_PTR(count);
2200 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2203 return ERR_PTR(-ENOMEM);
2205 for (descs->ndescs = 0; descs->ndescs < count; ) {
2206 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2208 gpiod_put_array(descs);
2209 return ERR_CAST(desc);
2211 descs->desc[descs->ndescs] = desc;
2216 EXPORT_SYMBOL_GPL(gpiod_get_array);
2219 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2221 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2222 * @con_id: function within the GPIO consumer
2223 * @flags: optional GPIO initialization flags
2225 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2226 * assigned to the requested function it will return NULL.
2228 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2230 enum gpiod_flags flags)
2232 struct gpio_descs *descs;
2234 descs = gpiod_get_array(dev, con_id, flags);
2235 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2240 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2243 * gpiod_put - dispose of a GPIO descriptor
2244 * @desc: GPIO descriptor to dispose of
2246 * No descriptor can be used after gpiod_put() has been called on it.
2248 void gpiod_put(struct gpio_desc *desc)
2252 EXPORT_SYMBOL_GPL(gpiod_put);
2255 * gpiod_put_array - dispose of multiple GPIO descriptors
2256 * @descs: struct gpio_descs containing an array of descriptors
2258 void gpiod_put_array(struct gpio_descs *descs)
2262 for (i = 0; i < descs->ndescs; i++)
2263 gpiod_put(descs->desc[i]);
2267 EXPORT_SYMBOL_GPL(gpiod_put_array);
2269 #ifdef CONFIG_DEBUG_FS
2271 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2274 unsigned gpio = chip->base;
2275 struct gpio_desc *gdesc = &chip->desc[0];
2279 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2280 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
2283 gpiod_get_direction(gdesc);
2284 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2285 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2286 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
2288 is_out ? "out" : "in ",
2290 ? (chip->get(chip, i) ? "hi" : "lo")
2292 is_irq ? "IRQ" : " ");
2293 seq_printf(s, "\n");
2297 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2299 unsigned long flags;
2300 struct gpio_chip *chip = NULL;
2301 loff_t index = *pos;
2305 spin_lock_irqsave(&gpio_lock, flags);
2306 list_for_each_entry(chip, &gpio_chips, list)
2308 spin_unlock_irqrestore(&gpio_lock, flags);
2311 spin_unlock_irqrestore(&gpio_lock, flags);
2316 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2318 unsigned long flags;
2319 struct gpio_chip *chip = v;
2322 spin_lock_irqsave(&gpio_lock, flags);
2323 if (list_is_last(&chip->list, &gpio_chips))
2326 ret = list_entry(chip->list.next, struct gpio_chip, list);
2327 spin_unlock_irqrestore(&gpio_lock, flags);
2335 static void gpiolib_seq_stop(struct seq_file *s, void *v)
2339 static int gpiolib_seq_show(struct seq_file *s, void *v)
2341 struct gpio_chip *chip = v;
2344 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2345 chip->base, chip->base + chip->ngpio - 1);
2348 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2351 seq_printf(s, ", %s", chip->label);
2352 if (chip->can_sleep)
2353 seq_printf(s, ", can sleep");
2354 seq_printf(s, ":\n");
2357 chip->dbg_show(s, chip);
2359 gpiolib_dbg_show(s, chip);
2364 static const struct seq_operations gpiolib_seq_ops = {
2365 .start = gpiolib_seq_start,
2366 .next = gpiolib_seq_next,
2367 .stop = gpiolib_seq_stop,
2368 .show = gpiolib_seq_show,
2371 static int gpiolib_open(struct inode *inode, struct file *file)
2373 return seq_open(file, &gpiolib_seq_ops);
2376 static const struct file_operations gpiolib_operations = {
2377 .owner = THIS_MODULE,
2378 .open = gpiolib_open,
2380 .llseek = seq_lseek,
2381 .release = seq_release,
2384 static int __init gpiolib_debugfs_init(void)
2386 /* /sys/kernel/debug/gpio */
2387 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2388 NULL, NULL, &gpiolib_operations);
2391 subsys_initcall(gpiolib_debugfs_init);
2393 #endif /* DEBUG_FS */