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 status = of_gpiochip_add(chip);
295 goto err_remove_chip;
297 acpi_gpiochip_add(chip);
299 status = gpiochip_sysfs_register(chip);
301 goto err_remove_chip;
303 pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
304 chip->base, chip->base + chip->ngpio - 1,
305 chip->label ? : "generic");
310 acpi_gpiochip_remove(chip);
311 gpiochip_free_hogs(chip);
312 of_gpiochip_remove(chip);
313 spin_lock_irqsave(&gpio_lock, flags);
314 list_del(&chip->list);
315 spin_unlock_irqrestore(&gpio_lock, flags);
320 /* failures here can mean systems won't boot... */
321 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
322 chip->base, chip->base + chip->ngpio - 1,
323 chip->label ? : "generic");
326 EXPORT_SYMBOL_GPL(gpiochip_add);
329 * gpiochip_remove() - unregister a gpio_chip
330 * @chip: the chip to unregister
332 * A gpio_chip with any GPIOs still requested may not be removed.
334 void gpiochip_remove(struct gpio_chip *chip)
336 struct gpio_desc *desc;
339 bool requested = false;
341 gpiochip_sysfs_unregister(chip);
343 gpiochip_irqchip_remove(chip);
345 acpi_gpiochip_remove(chip);
346 gpiochip_remove_pin_ranges(chip);
347 gpiochip_free_hogs(chip);
348 of_gpiochip_remove(chip);
350 spin_lock_irqsave(&gpio_lock, flags);
351 for (id = 0; id < chip->ngpio; id++) {
352 desc = &chip->desc[id];
354 if (test_bit(FLAG_REQUESTED, &desc->flags))
357 list_del(&chip->list);
358 spin_unlock_irqrestore(&gpio_lock, flags);
361 dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
366 EXPORT_SYMBOL_GPL(gpiochip_remove);
369 * gpiochip_find() - iterator for locating a specific gpio_chip
370 * @data: data to pass to match function
371 * @callback: Callback function to check gpio_chip
373 * Similar to bus_find_device. It returns a reference to a gpio_chip as
374 * determined by a user supplied @match callback. The callback should return
375 * 0 if the device doesn't match and non-zero if it does. If the callback is
376 * non-zero, this function will return to the caller and not iterate over any
379 struct gpio_chip *gpiochip_find(void *data,
380 int (*match)(struct gpio_chip *chip,
383 struct gpio_chip *chip;
386 spin_lock_irqsave(&gpio_lock, flags);
387 list_for_each_entry(chip, &gpio_chips, list)
388 if (match(chip, data))
392 if (&chip->list == &gpio_chips)
394 spin_unlock_irqrestore(&gpio_lock, flags);
398 EXPORT_SYMBOL_GPL(gpiochip_find);
400 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
402 const char *name = data;
404 return !strcmp(chip->label, name);
407 static struct gpio_chip *find_chip_by_name(const char *name)
409 return gpiochip_find((void *)name, gpiochip_match_name);
412 #ifdef CONFIG_GPIOLIB_IRQCHIP
415 * The following is irqchip helper code for gpiochips.
419 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
420 * @gpiochip: the gpiochip to set the irqchip chain to
421 * @irqchip: the irqchip to chain to the gpiochip
422 * @parent_irq: the irq number corresponding to the parent IRQ for this
424 * @parent_handler: the parent interrupt handler for the accumulated IRQ
425 * coming out of the gpiochip. If the interrupt is nested rather than
426 * cascaded, pass NULL in this handler argument
428 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
429 struct irq_chip *irqchip,
431 irq_flow_handler_t parent_handler)
435 if (!gpiochip->irqdomain) {
436 chip_err(gpiochip, "called %s before setting up irqchip\n",
441 if (parent_handler) {
442 if (gpiochip->can_sleep) {
444 "you cannot have chained interrupts on a "
445 "chip that may sleep\n");
449 * The parent irqchip is already using the chip_data for this
450 * irqchip, so our callbacks simply use the handler_data.
452 irq_set_chained_handler_and_data(parent_irq, parent_handler,
455 gpiochip->irq_parent = parent_irq;
458 /* Set the parent IRQ for all affected IRQs */
459 for (offset = 0; offset < gpiochip->ngpio; offset++)
460 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
463 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
466 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
467 * @d: the irqdomain used by this irqchip
468 * @irq: the global irq number used by this GPIO irqchip irq
469 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
471 * This function will set up the mapping for a certain IRQ line on a
472 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
473 * stored inside the gpiochip.
475 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
476 irq_hw_number_t hwirq)
478 struct gpio_chip *chip = d->host_data;
480 irq_set_chip_data(irq, chip);
482 * This lock class tells lockdep that GPIO irqs are in a different
483 * category than their parents, so it won't report false recursion.
485 irq_set_lockdep_class(irq, chip->lock_key);
486 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
487 /* Chips that can sleep need nested thread handlers */
488 if (chip->can_sleep && !chip->irq_not_threaded)
489 irq_set_nested_thread(irq, 1);
490 irq_set_noprobe(irq);
493 * No set-up of the hardware will happen if IRQ_TYPE_NONE
494 * is passed as default type.
496 if (chip->irq_default_type != IRQ_TYPE_NONE)
497 irq_set_irq_type(irq, chip->irq_default_type);
502 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
504 struct gpio_chip *chip = d->host_data;
507 irq_set_nested_thread(irq, 0);
508 irq_set_chip_and_handler(irq, NULL, NULL);
509 irq_set_chip_data(irq, NULL);
512 static const struct irq_domain_ops gpiochip_domain_ops = {
513 .map = gpiochip_irq_map,
514 .unmap = gpiochip_irq_unmap,
515 /* Virtually all GPIO irqchips are twocell:ed */
516 .xlate = irq_domain_xlate_twocell,
519 static int gpiochip_irq_reqres(struct irq_data *d)
521 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
523 if (!try_module_get(chip->owner))
526 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
528 "unable to lock HW IRQ %lu for IRQ\n",
530 module_put(chip->owner);
536 static void gpiochip_irq_relres(struct irq_data *d)
538 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
540 gpiochip_unlock_as_irq(chip, d->hwirq);
541 module_put(chip->owner);
544 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
546 return irq_find_mapping(chip->irqdomain, offset);
550 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
551 * @gpiochip: the gpiochip to remove the irqchip from
553 * This is called only from gpiochip_remove()
555 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
559 acpi_gpiochip_free_interrupts(gpiochip);
561 if (gpiochip->irq_parent) {
562 irq_set_chained_handler(gpiochip->irq_parent, NULL);
563 irq_set_handler_data(gpiochip->irq_parent, NULL);
566 /* Remove all IRQ mappings and delete the domain */
567 if (gpiochip->irqdomain) {
568 for (offset = 0; offset < gpiochip->ngpio; offset++)
570 irq_find_mapping(gpiochip->irqdomain, offset));
571 irq_domain_remove(gpiochip->irqdomain);
574 if (gpiochip->irqchip) {
575 gpiochip->irqchip->irq_request_resources = NULL;
576 gpiochip->irqchip->irq_release_resources = NULL;
577 gpiochip->irqchip = NULL;
582 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
583 * @gpiochip: the gpiochip to add the irqchip to
584 * @irqchip: the irqchip to add to the gpiochip
585 * @first_irq: if not dynamically assigned, the base (first) IRQ to
586 * allocate gpiochip irqs from
587 * @handler: the irq handler to use (often a predefined irq core function)
588 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
589 * to have the core avoid setting up any default type in the hardware.
590 * @lock_key: lockdep class
592 * This function closely associates a certain irqchip with a certain
593 * gpiochip, providing an irq domain to translate the local IRQs to
594 * global irqs in the gpiolib core, and making sure that the gpiochip
595 * is passed as chip data to all related functions. Driver callbacks
596 * need to use container_of() to get their local state containers back
597 * from the gpiochip passed as chip data. An irqdomain will be stored
598 * in the gpiochip that shall be used by the driver to handle IRQ number
599 * translation. The gpiochip will need to be initialized and registered
600 * before calling this function.
602 * This function will handle two cell:ed simple IRQs and assumes all
603 * the pins on the gpiochip can generate a unique IRQ. Everything else
604 * need to be open coded.
606 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
607 struct irq_chip *irqchip,
608 unsigned int first_irq,
609 irq_flow_handler_t handler,
611 struct lock_class_key *lock_key)
613 struct device_node *of_node;
615 unsigned irq_base = 0;
617 if (!gpiochip || !irqchip)
620 if (!gpiochip->dev) {
621 pr_err("missing gpiochip .dev parent pointer\n");
624 of_node = gpiochip->dev->of_node;
625 #ifdef CONFIG_OF_GPIO
627 * If the gpiochip has an assigned OF node this takes precedence
628 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
630 if (gpiochip->of_node)
631 of_node = gpiochip->of_node;
633 gpiochip->irqchip = irqchip;
634 gpiochip->irq_handler = handler;
635 gpiochip->irq_default_type = type;
636 gpiochip->to_irq = gpiochip_to_irq;
637 gpiochip->lock_key = lock_key;
638 gpiochip->irqdomain = irq_domain_add_simple(of_node,
639 gpiochip->ngpio, first_irq,
640 &gpiochip_domain_ops, gpiochip);
641 if (!gpiochip->irqdomain) {
642 gpiochip->irqchip = NULL;
647 * It is possible for a driver to override this, but only if the
648 * alternative functions are both implemented.
650 if (!irqchip->irq_request_resources &&
651 !irqchip->irq_release_resources) {
652 irqchip->irq_request_resources = gpiochip_irq_reqres;
653 irqchip->irq_release_resources = gpiochip_irq_relres;
657 * Prepare the mapping since the irqchip shall be orthogonal to
658 * any gpiochip calls. If the first_irq was zero, this is
659 * necessary to allocate descriptors for all IRQs.
661 for (offset = 0; offset < gpiochip->ngpio; offset++) {
662 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
665 * Store the base into the gpiochip to be used when
666 * unmapping the irqs.
668 gpiochip->irq_base = irq_base;
671 acpi_gpiochip_request_interrupts(gpiochip);
675 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
677 #else /* CONFIG_GPIOLIB_IRQCHIP */
679 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
681 #endif /* CONFIG_GPIOLIB_IRQCHIP */
683 #ifdef CONFIG_PINCTRL
686 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
687 * @chip: the gpiochip to add the range for
688 * @pctldev: the pin controller to map to
689 * @gpio_offset: the start offset in the current gpio_chip number space
690 * @pin_group: name of the pin group inside the pin controller
692 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
693 struct pinctrl_dev *pctldev,
694 unsigned int gpio_offset, const char *pin_group)
696 struct gpio_pin_range *pin_range;
699 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
701 chip_err(chip, "failed to allocate pin ranges\n");
705 /* Use local offset as range ID */
706 pin_range->range.id = gpio_offset;
707 pin_range->range.gc = chip;
708 pin_range->range.name = chip->label;
709 pin_range->range.base = chip->base + gpio_offset;
710 pin_range->pctldev = pctldev;
712 ret = pinctrl_get_group_pins(pctldev, pin_group,
713 &pin_range->range.pins,
714 &pin_range->range.npins);
720 pinctrl_add_gpio_range(pctldev, &pin_range->range);
722 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
723 gpio_offset, gpio_offset + pin_range->range.npins - 1,
724 pinctrl_dev_get_devname(pctldev), pin_group);
726 list_add_tail(&pin_range->node, &chip->pin_ranges);
730 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
733 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
734 * @chip: the gpiochip to add the range for
735 * @pinctrl_name: the dev_name() of the pin controller to map to
736 * @gpio_offset: the start offset in the current gpio_chip number space
737 * @pin_offset: the start offset in the pin controller number space
738 * @npins: the number of pins from the offset of each pin space (GPIO and
739 * pin controller) to accumulate in this range
741 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
742 unsigned int gpio_offset, unsigned int pin_offset,
745 struct gpio_pin_range *pin_range;
748 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
750 chip_err(chip, "failed to allocate pin ranges\n");
754 /* Use local offset as range ID */
755 pin_range->range.id = gpio_offset;
756 pin_range->range.gc = chip;
757 pin_range->range.name = chip->label;
758 pin_range->range.base = chip->base + gpio_offset;
759 pin_range->range.pin_base = pin_offset;
760 pin_range->range.npins = npins;
761 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
763 if (IS_ERR(pin_range->pctldev)) {
764 ret = PTR_ERR(pin_range->pctldev);
765 chip_err(chip, "could not create pin range\n");
769 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
770 gpio_offset, gpio_offset + npins - 1,
772 pin_offset, pin_offset + npins - 1);
774 list_add_tail(&pin_range->node, &chip->pin_ranges);
778 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
781 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
782 * @chip: the chip to remove all the mappings for
784 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
786 struct gpio_pin_range *pin_range, *tmp;
788 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
789 list_del(&pin_range->node);
790 pinctrl_remove_gpio_range(pin_range->pctldev,
795 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
797 #endif /* CONFIG_PINCTRL */
799 /* These "optional" allocation calls help prevent drivers from stomping
800 * on each other, and help provide better diagnostics in debugfs.
801 * They're called even less than the "set direction" calls.
803 static int __gpiod_request(struct gpio_desc *desc, const char *label)
805 struct gpio_chip *chip = desc->chip;
809 spin_lock_irqsave(&gpio_lock, flags);
811 /* NOTE: gpio_request() can be called in early boot,
812 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
815 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
816 desc_set_label(desc, label ? : "?");
824 /* chip->request may sleep */
825 spin_unlock_irqrestore(&gpio_lock, flags);
826 status = chip->request(chip, gpio_chip_hwgpio(desc));
827 spin_lock_irqsave(&gpio_lock, flags);
830 desc_set_label(desc, NULL);
831 clear_bit(FLAG_REQUESTED, &desc->flags);
835 if (chip->get_direction) {
836 /* chip->get_direction may sleep */
837 spin_unlock_irqrestore(&gpio_lock, flags);
838 gpiod_get_direction(desc);
839 spin_lock_irqsave(&gpio_lock, flags);
842 spin_unlock_irqrestore(&gpio_lock, flags);
846 int gpiod_request(struct gpio_desc *desc, const char *label)
848 int status = -EPROBE_DEFER;
849 struct gpio_chip *chip;
852 pr_warn("%s: invalid GPIO\n", __func__);
860 if (try_module_get(chip->owner)) {
861 status = __gpiod_request(desc, label);
863 module_put(chip->owner);
868 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
873 static bool __gpiod_free(struct gpio_desc *desc)
877 struct gpio_chip *chip;
881 gpiod_unexport(desc);
883 spin_lock_irqsave(&gpio_lock, flags);
886 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
888 spin_unlock_irqrestore(&gpio_lock, flags);
889 might_sleep_if(chip->can_sleep);
890 chip->free(chip, gpio_chip_hwgpio(desc));
891 spin_lock_irqsave(&gpio_lock, flags);
893 desc_set_label(desc, NULL);
894 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
895 clear_bit(FLAG_REQUESTED, &desc->flags);
896 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
897 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
898 clear_bit(FLAG_IS_HOGGED, &desc->flags);
902 spin_unlock_irqrestore(&gpio_lock, flags);
906 void gpiod_free(struct gpio_desc *desc)
908 if (desc && __gpiod_free(desc))
909 module_put(desc->chip->owner);
911 WARN_ON(extra_checks);
915 * gpiochip_is_requested - return string iff signal was requested
916 * @chip: controller managing the signal
917 * @offset: of signal within controller's 0..(ngpio - 1) range
919 * Returns NULL if the GPIO is not currently requested, else a string.
920 * The string returned is the label passed to gpio_request(); if none has been
921 * passed it is a meaningless, non-NULL constant.
923 * This function is for use by GPIO controller drivers. The label can
924 * help with diagnostics, and knowing that the signal is used as a GPIO
925 * can help avoid accidentally multiplexing it to another controller.
927 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
929 struct gpio_desc *desc;
931 if (!GPIO_OFFSET_VALID(chip, offset))
934 desc = &chip->desc[offset];
936 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
940 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
943 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
944 * @desc: GPIO descriptor to request
945 * @label: label for the GPIO
947 * Function allows GPIO chip drivers to request and use their own GPIO
948 * descriptors via gpiolib API. Difference to gpiod_request() is that this
949 * function will not increase reference count of the GPIO chip module. This
950 * allows the GPIO chip module to be unloaded as needed (we assume that the
951 * GPIO chip driver handles freeing the GPIOs it has requested).
953 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
956 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
960 chip_err(chip, "failed to get GPIO descriptor\n");
964 err = __gpiod_request(desc, label);
970 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
973 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
974 * @desc: GPIO descriptor to free
976 * Function frees the given GPIO requested previously with
977 * gpiochip_request_own_desc().
979 void gpiochip_free_own_desc(struct gpio_desc *desc)
984 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
986 /* Drivers MUST set GPIO direction before making get/set calls. In
987 * some cases this is done in early boot, before IRQs are enabled.
989 * As a rule these aren't called more than once (except for drivers
990 * using the open-drain emulation idiom) so these are natural places
991 * to accumulate extra debugging checks. Note that we can't (yet)
992 * rely on gpio_request() having been called beforehand.
996 * gpiod_direction_input - set the GPIO direction to input
997 * @desc: GPIO to set to input
999 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1000 * be called safely on it.
1002 * Return 0 in case of success, else an error code.
1004 int gpiod_direction_input(struct gpio_desc *desc)
1006 struct gpio_chip *chip;
1007 int status = -EINVAL;
1009 if (!desc || !desc->chip) {
1010 pr_warn("%s: invalid GPIO\n", __func__);
1015 if (!chip->get || !chip->direction_input) {
1017 "%s: missing get() or direction_input() operations\n",
1022 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1024 clear_bit(FLAG_IS_OUT, &desc->flags);
1026 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1030 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1032 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1034 struct gpio_chip *chip;
1035 int status = -EINVAL;
1037 /* GPIOs used for IRQs shall not be set as output */
1038 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1040 "%s: tried to set a GPIO tied to an IRQ as output\n",
1045 /* Open drain pin should not be driven to 1 */
1046 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1047 return gpiod_direction_input(desc);
1049 /* Open source pin should not be driven to 0 */
1050 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1051 return gpiod_direction_input(desc);
1054 if (!chip->set || !chip->direction_output) {
1056 "%s: missing set() or direction_output() operations\n",
1061 status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
1063 set_bit(FLAG_IS_OUT, &desc->flags);
1064 trace_gpio_value(desc_to_gpio(desc), 0, value);
1065 trace_gpio_direction(desc_to_gpio(desc), 0, status);
1070 * gpiod_direction_output_raw - set the GPIO direction to output
1071 * @desc: GPIO to set to output
1072 * @value: initial output value of the GPIO
1074 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1075 * be called safely on it. The initial value of the output must be specified
1076 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1078 * Return 0 in case of success, else an error code.
1080 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1082 if (!desc || !desc->chip) {
1083 pr_warn("%s: invalid GPIO\n", __func__);
1086 return _gpiod_direction_output_raw(desc, value);
1088 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1091 * gpiod_direction_output - set the GPIO direction to output
1092 * @desc: GPIO to set to output
1093 * @value: initial output value of the GPIO
1095 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1096 * be called safely on it. The initial value of the output must be specified
1097 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1100 * Return 0 in case of success, else an error code.
1102 int gpiod_direction_output(struct gpio_desc *desc, int value)
1104 if (!desc || !desc->chip) {
1105 pr_warn("%s: invalid GPIO\n", __func__);
1108 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1110 return _gpiod_direction_output_raw(desc, value);
1112 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1115 * gpiod_set_debounce - sets @debounce time for a @gpio
1116 * @gpio: the gpio to set debounce time
1117 * @debounce: debounce time is microseconds
1119 * returns -ENOTSUPP if the controller does not support setting
1122 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1124 struct gpio_chip *chip;
1126 if (!desc || !desc->chip) {
1127 pr_warn("%s: invalid GPIO\n", __func__);
1132 if (!chip->set || !chip->set_debounce) {
1134 "%s: missing set() or set_debounce() operations\n",
1139 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1141 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1144 * gpiod_is_active_low - test whether a GPIO is active-low or not
1145 * @desc: the gpio descriptor to test
1147 * Returns 1 if the GPIO is active-low, 0 otherwise.
1149 int gpiod_is_active_low(const struct gpio_desc *desc)
1151 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1153 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1155 /* I/O calls are only valid after configuration completed; the relevant
1156 * "is this a valid GPIO" error checks should already have been done.
1158 * "Get" operations are often inlinable as reading a pin value register,
1159 * and masking the relevant bit in that register.
1161 * When "set" operations are inlinable, they involve writing that mask to
1162 * one register to set a low value, or a different register to set it high.
1163 * Otherwise locking is needed, so there may be little value to inlining.
1165 *------------------------------------------------------------------------
1167 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1168 * have requested the GPIO. That can include implicit requesting by
1169 * a direction setting call. Marking a gpio as requested locks its chip
1170 * in memory, guaranteeing that these table lookups need no more locking
1171 * and that gpiochip_remove() will fail.
1173 * REVISIT when debugging, consider adding some instrumentation to ensure
1174 * that the GPIO was actually requested.
1177 static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
1179 struct gpio_chip *chip;
1184 offset = gpio_chip_hwgpio(desc);
1185 value = chip->get ? chip->get(chip, offset) : false;
1186 trace_gpio_value(desc_to_gpio(desc), 1, value);
1191 * gpiod_get_raw_value() - return a gpio's raw value
1192 * @desc: gpio whose value will be returned
1194 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1195 * its ACTIVE_LOW status.
1197 * This function should be called from contexts where we cannot sleep, and will
1198 * complain if the GPIO chip functions potentially sleep.
1200 int gpiod_get_raw_value(const struct gpio_desc *desc)
1204 /* Should be using gpio_get_value_cansleep() */
1205 WARN_ON(desc->chip->can_sleep);
1206 return _gpiod_get_raw_value(desc);
1208 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1211 * gpiod_get_value() - return a gpio's value
1212 * @desc: gpio whose value will be returned
1214 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1217 * This function should be called from contexts where we cannot sleep, and will
1218 * complain if the GPIO chip functions potentially sleep.
1220 int gpiod_get_value(const struct gpio_desc *desc)
1225 /* Should be using gpio_get_value_cansleep() */
1226 WARN_ON(desc->chip->can_sleep);
1228 value = _gpiod_get_raw_value(desc);
1229 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1234 EXPORT_SYMBOL_GPL(gpiod_get_value);
1237 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1238 * @desc: gpio descriptor whose state need to be set.
1239 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1241 static void _gpio_set_open_drain_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_input(chip, offset);
1250 clear_bit(FLAG_IS_OUT, &desc->flags);
1252 err = chip->direction_output(chip, offset, 0);
1254 set_bit(FLAG_IS_OUT, &desc->flags);
1256 trace_gpio_direction(desc_to_gpio(desc), value, err);
1259 "%s: Error in set_value for open drain err %d\n",
1264 * _gpio_set_open_source_value() - Set the open source gpio's value.
1265 * @desc: gpio descriptor whose state need to be set.
1266 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1268 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1271 struct gpio_chip *chip = desc->chip;
1272 int offset = gpio_chip_hwgpio(desc);
1275 err = chip->direction_output(chip, offset, 1);
1277 set_bit(FLAG_IS_OUT, &desc->flags);
1279 err = chip->direction_input(chip, offset);
1281 clear_bit(FLAG_IS_OUT, &desc->flags);
1283 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1286 "%s: Error in set_value for open source err %d\n",
1290 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1292 struct gpio_chip *chip;
1295 trace_gpio_value(desc_to_gpio(desc), 0, value);
1296 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1297 _gpio_set_open_drain_value(desc, value);
1298 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1299 _gpio_set_open_source_value(desc, value);
1301 chip->set(chip, gpio_chip_hwgpio(desc), value);
1305 * set multiple outputs on the same chip;
1306 * use the chip's set_multiple function if available;
1307 * otherwise set the outputs sequentially;
1308 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1309 * defines which outputs are to be changed
1310 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1311 * defines the values the outputs specified by mask are to be set to
1313 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1314 unsigned long *mask, unsigned long *bits)
1316 if (chip->set_multiple) {
1317 chip->set_multiple(chip, mask, bits);
1320 for (i = 0; i < chip->ngpio; i++) {
1321 if (mask[BIT_WORD(i)] == 0) {
1322 /* no more set bits in this mask word;
1323 * skip ahead to the next word */
1324 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1327 /* set outputs if the corresponding mask bit is set */
1328 if (__test_and_clear_bit(i, mask))
1329 chip->set(chip, i, test_bit(i, bits));
1334 static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
1335 unsigned int array_size,
1336 struct gpio_desc **desc_array,
1341 while (i < array_size) {
1342 struct gpio_chip *chip = desc_array[i]->chip;
1343 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1344 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1348 WARN_ON(chip->can_sleep);
1350 memset(mask, 0, sizeof(mask));
1352 struct gpio_desc *desc = desc_array[i];
1353 int hwgpio = gpio_chip_hwgpio(desc);
1354 int value = value_array[i];
1356 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1358 trace_gpio_value(desc_to_gpio(desc), 0, value);
1360 * collect all normal outputs belonging to the same chip
1361 * open drain and open source outputs are set individually
1363 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1364 _gpio_set_open_drain_value(desc, value);
1365 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1366 _gpio_set_open_source_value(desc, value);
1368 __set_bit(hwgpio, mask);
1370 __set_bit(hwgpio, bits);
1372 __clear_bit(hwgpio, bits);
1376 } while ((i < array_size) && (desc_array[i]->chip == chip));
1377 /* push collected bits to outputs */
1379 gpio_chip_set_multiple(chip, mask, bits);
1384 * gpiod_set_raw_value() - assign a gpio's raw value
1385 * @desc: gpio whose value will be assigned
1386 * @value: value to assign
1388 * Set the raw value of the GPIO, i.e. the value of its physical line without
1389 * regard for its ACTIVE_LOW status.
1391 * This function should be called from contexts where we cannot sleep, and will
1392 * complain if the GPIO chip functions potentially sleep.
1394 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1398 /* Should be using gpio_set_value_cansleep() */
1399 WARN_ON(desc->chip->can_sleep);
1400 _gpiod_set_raw_value(desc, value);
1402 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1405 * gpiod_set_value() - assign a gpio's value
1406 * @desc: gpio whose value will be assigned
1407 * @value: value to assign
1409 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
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_value(struct gpio_desc *desc, int value)
1419 /* Should be using gpio_set_value_cansleep() */
1420 WARN_ON(desc->chip->can_sleep);
1421 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1423 _gpiod_set_raw_value(desc, value);
1425 EXPORT_SYMBOL_GPL(gpiod_set_value);
1428 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1429 * @array_size: number of elements in the descriptor / value arrays
1430 * @desc_array: array of GPIO descriptors whose values will be assigned
1431 * @value_array: array of values to assign
1433 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1434 * without regard for their ACTIVE_LOW status.
1436 * This function should be called from contexts where we cannot sleep, and will
1437 * complain if the GPIO chip functions potentially sleep.
1439 void gpiod_set_raw_array_value(unsigned int array_size,
1440 struct gpio_desc **desc_array, int *value_array)
1444 gpiod_set_array_value_priv(true, false, array_size, desc_array,
1447 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
1450 * gpiod_set_array_value() - assign values to an array of GPIOs
1451 * @array_size: number of elements in the descriptor / value arrays
1452 * @desc_array: array of GPIO descriptors whose values will be assigned
1453 * @value_array: array of values to assign
1455 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1458 * This function should be called from contexts where we cannot sleep, and will
1459 * complain if the GPIO chip functions potentially sleep.
1461 void gpiod_set_array_value(unsigned int array_size,
1462 struct gpio_desc **desc_array, int *value_array)
1466 gpiod_set_array_value_priv(false, false, array_size, desc_array,
1469 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
1472 * gpiod_cansleep() - report whether gpio value access may sleep
1473 * @desc: gpio to check
1476 int gpiod_cansleep(const struct gpio_desc *desc)
1480 return desc->chip->can_sleep;
1482 EXPORT_SYMBOL_GPL(gpiod_cansleep);
1485 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1486 * @desc: gpio whose IRQ will be returned (already requested)
1488 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1491 int gpiod_to_irq(const struct gpio_desc *desc)
1493 struct gpio_chip *chip;
1499 offset = gpio_chip_hwgpio(desc);
1500 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
1502 EXPORT_SYMBOL_GPL(gpiod_to_irq);
1505 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1506 * @chip: the chip the GPIO to lock belongs to
1507 * @offset: the offset of the GPIO to lock as IRQ
1509 * This is used directly by GPIO drivers that want to lock down
1510 * a certain GPIO line to be used for IRQs.
1512 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
1514 if (offset >= chip->ngpio)
1517 if (test_bit(FLAG_IS_OUT, &chip->desc[offset].flags)) {
1519 "%s: tried to flag a GPIO set as output for IRQ\n",
1524 set_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1527 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
1530 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1531 * @chip: the chip the GPIO to lock belongs to
1532 * @offset: the offset of the GPIO to lock as IRQ
1534 * This is used directly by GPIO drivers that want to indicate
1535 * that a certain GPIO is no longer used exclusively for IRQ.
1537 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
1539 if (offset >= chip->ngpio)
1542 clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1544 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
1547 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1548 * @desc: gpio whose value will be returned
1550 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1551 * its ACTIVE_LOW status.
1553 * This function is to be called from contexts that can sleep.
1555 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
1557 might_sleep_if(extra_checks);
1560 return _gpiod_get_raw_value(desc);
1562 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
1565 * gpiod_get_value_cansleep() - return a gpio's value
1566 * @desc: gpio whose value will be returned
1568 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1571 * This function is to be called from contexts that can sleep.
1573 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
1577 might_sleep_if(extra_checks);
1581 value = _gpiod_get_raw_value(desc);
1582 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1587 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
1590 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
1591 * @desc: gpio whose value will be assigned
1592 * @value: value to assign
1594 * Set the raw value of the GPIO, i.e. the value of its physical line without
1595 * regard for its ACTIVE_LOW status.
1597 * This function is to be called from contexts that can sleep.
1599 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
1601 might_sleep_if(extra_checks);
1604 _gpiod_set_raw_value(desc, value);
1606 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
1609 * gpiod_set_value_cansleep() - assign a gpio's value
1610 * @desc: gpio whose value will be assigned
1611 * @value: value to assign
1613 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1616 * This function is to be called from contexts that can sleep.
1618 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
1620 might_sleep_if(extra_checks);
1624 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1626 _gpiod_set_raw_value(desc, value);
1628 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
1631 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
1632 * @array_size: number of elements in the descriptor / value arrays
1633 * @desc_array: array of GPIO descriptors whose values will be assigned
1634 * @value_array: array of values to assign
1636 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1637 * without regard for their ACTIVE_LOW status.
1639 * This function is to be called from contexts that can sleep.
1641 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
1642 struct gpio_desc **desc_array,
1645 might_sleep_if(extra_checks);
1648 gpiod_set_array_value_priv(true, true, array_size, desc_array,
1651 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
1654 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
1655 * @array_size: number of elements in the descriptor / value arrays
1656 * @desc_array: array of GPIO descriptors whose values will be assigned
1657 * @value_array: array of values to assign
1659 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1662 * This function is to be called from contexts that can sleep.
1664 void gpiod_set_array_value_cansleep(unsigned int array_size,
1665 struct gpio_desc **desc_array,
1668 might_sleep_if(extra_checks);
1671 gpiod_set_array_value_priv(false, true, array_size, desc_array,
1674 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
1677 * gpiod_add_lookup_table() - register GPIO device consumers
1678 * @table: table of consumers to register
1680 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
1682 mutex_lock(&gpio_lookup_lock);
1684 list_add_tail(&table->list, &gpio_lookup_list);
1686 mutex_unlock(&gpio_lookup_lock);
1690 * gpiod_remove_lookup_table() - unregister GPIO device consumers
1691 * @table: table of consumers to unregister
1693 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
1695 mutex_lock(&gpio_lookup_lock);
1697 list_del(&table->list);
1699 mutex_unlock(&gpio_lookup_lock);
1702 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
1704 enum gpio_lookup_flags *flags)
1706 char prop_name[32]; /* 32 is max size of property name */
1707 enum of_gpio_flags of_flags;
1708 struct gpio_desc *desc;
1711 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1713 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
1716 snprintf(prop_name, sizeof(prop_name), "%s",
1719 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
1721 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1728 if (of_flags & OF_GPIO_ACTIVE_LOW)
1729 *flags |= GPIO_ACTIVE_LOW;
1734 static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
1736 enum gpio_lookup_flags *flags)
1738 struct acpi_device *adev = ACPI_COMPANION(dev);
1739 struct acpi_gpio_info info;
1740 struct gpio_desc *desc;
1744 /* Try first from _DSD */
1745 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1746 if (con_id && strcmp(con_id, "gpios")) {
1747 snprintf(propname, sizeof(propname), "%s-%s",
1748 con_id, gpio_suffixes[i]);
1750 snprintf(propname, sizeof(propname), "%s",
1754 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
1755 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1759 /* Then from plain _CRS GPIOs */
1761 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
1766 if (info.active_low)
1767 *flags |= GPIO_ACTIVE_LOW;
1772 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
1774 const char *dev_id = dev ? dev_name(dev) : NULL;
1775 struct gpiod_lookup_table *table;
1777 mutex_lock(&gpio_lookup_lock);
1779 list_for_each_entry(table, &gpio_lookup_list, list) {
1780 if (table->dev_id && dev_id) {
1782 * Valid strings on both ends, must be identical to have
1785 if (!strcmp(table->dev_id, dev_id))
1789 * One of the pointers is NULL, so both must be to have
1792 if (dev_id == table->dev_id)
1799 mutex_unlock(&gpio_lookup_lock);
1803 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
1805 enum gpio_lookup_flags *flags)
1807 struct gpio_desc *desc = ERR_PTR(-ENOENT);
1808 struct gpiod_lookup_table *table;
1809 struct gpiod_lookup *p;
1811 table = gpiod_find_lookup_table(dev);
1815 for (p = &table->table[0]; p->chip_label; p++) {
1816 struct gpio_chip *chip;
1818 /* idx must always match exactly */
1822 /* If the lookup entry has a con_id, require exact match */
1823 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
1826 chip = find_chip_by_name(p->chip_label);
1829 dev_err(dev, "cannot find GPIO chip %s\n",
1831 return ERR_PTR(-ENODEV);
1834 if (chip->ngpio <= p->chip_hwnum) {
1836 "requested GPIO %d is out of range [0..%d] for chip %s\n",
1837 idx, chip->ngpio, chip->label);
1838 return ERR_PTR(-EINVAL);
1841 desc = gpiochip_get_desc(chip, p->chip_hwnum);
1850 static int dt_gpio_count(struct device *dev, const char *con_id)
1856 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1858 snprintf(propname, sizeof(propname), "%s-%s",
1859 con_id, gpio_suffixes[i]);
1861 snprintf(propname, sizeof(propname), "%s",
1864 ret = of_gpio_named_count(dev->of_node, propname);
1871 static int platform_gpio_count(struct device *dev, const char *con_id)
1873 struct gpiod_lookup_table *table;
1874 struct gpiod_lookup *p;
1875 unsigned int count = 0;
1877 table = gpiod_find_lookup_table(dev);
1881 for (p = &table->table[0]; p->chip_label; p++) {
1882 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
1883 (!con_id && !p->con_id))
1893 * gpiod_count - return the number of GPIOs associated with a device / function
1894 * or -ENOENT if no GPIO has been assigned to the requested function
1895 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1896 * @con_id: function within the GPIO consumer
1898 int gpiod_count(struct device *dev, const char *con_id)
1900 int count = -ENOENT;
1902 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
1903 count = dt_gpio_count(dev, con_id);
1904 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
1905 count = acpi_gpio_count(dev, con_id);
1908 count = platform_gpio_count(dev, con_id);
1912 EXPORT_SYMBOL_GPL(gpiod_count);
1915 * gpiod_get - obtain a GPIO for a given GPIO function
1916 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1917 * @con_id: function within the GPIO consumer
1918 * @flags: optional GPIO initialization flags
1920 * Return the GPIO descriptor corresponding to the function con_id of device
1921 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
1922 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
1924 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
1925 enum gpiod_flags flags)
1927 return gpiod_get_index(dev, con_id, 0, flags);
1929 EXPORT_SYMBOL_GPL(gpiod_get);
1932 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
1933 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1934 * @con_id: function within the GPIO consumer
1935 * @flags: optional GPIO initialization flags
1937 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
1938 * the requested function it will return NULL. This is convenient for drivers
1939 * that need to handle optional GPIOs.
1941 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
1943 enum gpiod_flags flags)
1945 return gpiod_get_index_optional(dev, con_id, 0, flags);
1947 EXPORT_SYMBOL_GPL(gpiod_get_optional);
1951 * gpiod_configure_flags - helper function to configure a given GPIO
1952 * @desc: gpio whose value will be assigned
1953 * @con_id: function within the GPIO consumer
1954 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
1956 * @dflags: gpiod_flags - optional GPIO initialization flags
1958 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
1959 * requested function and/or index, or another IS_ERR() code if an error
1960 * occurred while trying to acquire the GPIO.
1962 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
1963 unsigned long lflags, enum gpiod_flags dflags)
1967 if (lflags & GPIO_ACTIVE_LOW)
1968 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
1969 if (lflags & GPIO_OPEN_DRAIN)
1970 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
1971 if (lflags & GPIO_OPEN_SOURCE)
1972 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
1974 /* No particular flag request, return here... */
1975 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
1976 pr_debug("no flags found for %s\n", con_id);
1981 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
1982 status = gpiod_direction_output(desc,
1983 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
1985 status = gpiod_direction_input(desc);
1991 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
1992 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1993 * @con_id: function within the GPIO consumer
1994 * @idx: index of the GPIO to obtain in the consumer
1995 * @flags: optional GPIO initialization flags
1997 * This variant of gpiod_get() allows to access GPIOs other than the first
1998 * defined one for functions that define several GPIOs.
2000 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2001 * requested function and/or index, or another IS_ERR() code if an error
2002 * occurred while trying to acquire the GPIO.
2004 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2007 enum gpiod_flags flags)
2009 struct gpio_desc *desc = NULL;
2011 enum gpio_lookup_flags lookupflags = 0;
2013 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2016 /* Using device tree? */
2017 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
2018 dev_dbg(dev, "using device tree for GPIO lookup\n");
2019 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
2020 } else if (ACPI_COMPANION(dev)) {
2021 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2022 desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
2027 * Either we are not using DT or ACPI, or their lookup did not return
2028 * a result. In that case, use platform lookup as a fallback.
2030 if (!desc || desc == ERR_PTR(-ENOENT)) {
2031 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2032 desc = gpiod_find(dev, con_id, idx, &lookupflags);
2036 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2040 status = gpiod_request(desc, con_id);
2042 return ERR_PTR(status);
2044 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
2046 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2048 return ERR_PTR(status);
2053 EXPORT_SYMBOL_GPL(gpiod_get_index);
2056 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2057 * @fwnode: handle of the firmware node
2058 * @propname: name of the firmware property representing the GPIO
2060 * This function can be used for drivers that get their configuration
2063 * Function properly finds the corresponding GPIO using whatever is the
2064 * underlying firmware interface and then makes sure that the GPIO
2065 * descriptor is requested before it is returned to the caller.
2067 * In case of error an ERR_PTR() is returned.
2069 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2070 const char *propname)
2072 struct gpio_desc *desc = ERR_PTR(-ENODEV);
2073 bool active_low = false;
2077 return ERR_PTR(-EINVAL);
2079 if (is_of_node(fwnode)) {
2080 enum of_gpio_flags flags;
2082 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2085 active_low = flags & OF_GPIO_ACTIVE_LOW;
2086 } else if (is_acpi_node(fwnode)) {
2087 struct acpi_gpio_info info;
2089 desc = acpi_get_gpiod_by_index(to_acpi_node(fwnode), propname, 0,
2092 active_low = info.active_low;
2098 ret = gpiod_request(desc, NULL);
2100 return ERR_PTR(ret);
2102 /* Only value flag can be set from both DT and ACPI is active_low */
2104 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2108 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2111 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2113 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2114 * @con_id: function within the GPIO consumer
2115 * @index: index of the GPIO to obtain in the consumer
2116 * @flags: optional GPIO initialization flags
2118 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2119 * specified index was assigned to the requested function it will return NULL.
2120 * This is convenient for drivers that need to handle optional GPIOs.
2122 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2125 enum gpiod_flags flags)
2127 struct gpio_desc *desc;
2129 desc = gpiod_get_index(dev, con_id, index, flags);
2131 if (PTR_ERR(desc) == -ENOENT)
2137 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2140 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2141 * @desc: gpio whose value will be assigned
2142 * @name: gpio line name
2143 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2145 * @dflags: gpiod_flags - optional GPIO initialization flags
2147 int gpiod_hog(struct gpio_desc *desc, const char *name,
2148 unsigned long lflags, enum gpiod_flags dflags)
2150 struct gpio_chip *chip;
2151 struct gpio_desc *local_desc;
2155 chip = gpiod_to_chip(desc);
2156 hwnum = gpio_chip_hwgpio(desc);
2158 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2159 if (IS_ERR(local_desc)) {
2160 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2161 name, chip->label, hwnum);
2162 return PTR_ERR(local_desc);
2165 status = gpiod_configure_flags(desc, name, lflags, dflags);
2167 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2168 name, chip->label, hwnum);
2169 gpiochip_free_own_desc(desc);
2173 /* Mark GPIO as hogged so it can be identified and removed later */
2174 set_bit(FLAG_IS_HOGGED, &desc->flags);
2176 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2177 desc_to_gpio(desc), name,
2178 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2179 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2180 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2186 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2187 * @chip: gpio chip to act on
2189 * This is only used by of_gpiochip_remove to free hogged gpios
2191 static void gpiochip_free_hogs(struct gpio_chip *chip)
2195 for (id = 0; id < chip->ngpio; id++) {
2196 if (test_bit(FLAG_IS_HOGGED, &chip->desc[id].flags))
2197 gpiochip_free_own_desc(&chip->desc[id]);
2202 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2203 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2204 * @con_id: function within the GPIO consumer
2205 * @flags: optional GPIO initialization flags
2207 * This function acquires all the GPIOs defined under a given function.
2209 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2210 * no GPIO has been assigned to the requested function, or another IS_ERR()
2211 * code if an error occurred while trying to acquire the GPIOs.
2213 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2215 enum gpiod_flags flags)
2217 struct gpio_desc *desc;
2218 struct gpio_descs *descs;
2221 count = gpiod_count(dev, con_id);
2223 return ERR_PTR(count);
2225 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2228 return ERR_PTR(-ENOMEM);
2230 for (descs->ndescs = 0; descs->ndescs < count; ) {
2231 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2233 gpiod_put_array(descs);
2234 return ERR_CAST(desc);
2236 descs->desc[descs->ndescs] = desc;
2241 EXPORT_SYMBOL_GPL(gpiod_get_array);
2244 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2246 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2247 * @con_id: function within the GPIO consumer
2248 * @flags: optional GPIO initialization flags
2250 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2251 * assigned to the requested function it will return NULL.
2253 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2255 enum gpiod_flags flags)
2257 struct gpio_descs *descs;
2259 descs = gpiod_get_array(dev, con_id, flags);
2260 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2265 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2268 * gpiod_put - dispose of a GPIO descriptor
2269 * @desc: GPIO descriptor to dispose of
2271 * No descriptor can be used after gpiod_put() has been called on it.
2273 void gpiod_put(struct gpio_desc *desc)
2277 EXPORT_SYMBOL_GPL(gpiod_put);
2280 * gpiod_put_array - dispose of multiple GPIO descriptors
2281 * @descs: struct gpio_descs containing an array of descriptors
2283 void gpiod_put_array(struct gpio_descs *descs)
2287 for (i = 0; i < descs->ndescs; i++)
2288 gpiod_put(descs->desc[i]);
2292 EXPORT_SYMBOL_GPL(gpiod_put_array);
2294 #ifdef CONFIG_DEBUG_FS
2296 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2299 unsigned gpio = chip->base;
2300 struct gpio_desc *gdesc = &chip->desc[0];
2304 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2305 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
2308 gpiod_get_direction(gdesc);
2309 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2310 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2311 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
2313 is_out ? "out" : "in ",
2315 ? (chip->get(chip, i) ? "hi" : "lo")
2317 is_irq ? "IRQ" : " ");
2318 seq_printf(s, "\n");
2322 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2324 unsigned long flags;
2325 struct gpio_chip *chip = NULL;
2326 loff_t index = *pos;
2330 spin_lock_irqsave(&gpio_lock, flags);
2331 list_for_each_entry(chip, &gpio_chips, list)
2333 spin_unlock_irqrestore(&gpio_lock, flags);
2336 spin_unlock_irqrestore(&gpio_lock, flags);
2341 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2343 unsigned long flags;
2344 struct gpio_chip *chip = v;
2347 spin_lock_irqsave(&gpio_lock, flags);
2348 if (list_is_last(&chip->list, &gpio_chips))
2351 ret = list_entry(chip->list.next, struct gpio_chip, list);
2352 spin_unlock_irqrestore(&gpio_lock, flags);
2360 static void gpiolib_seq_stop(struct seq_file *s, void *v)
2364 static int gpiolib_seq_show(struct seq_file *s, void *v)
2366 struct gpio_chip *chip = v;
2369 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2370 chip->base, chip->base + chip->ngpio - 1);
2373 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2376 seq_printf(s, ", %s", chip->label);
2377 if (chip->can_sleep)
2378 seq_printf(s, ", can sleep");
2379 seq_printf(s, ":\n");
2382 chip->dbg_show(s, chip);
2384 gpiolib_dbg_show(s, chip);
2389 static const struct seq_operations gpiolib_seq_ops = {
2390 .start = gpiolib_seq_start,
2391 .next = gpiolib_seq_next,
2392 .stop = gpiolib_seq_stop,
2393 .show = gpiolib_seq_show,
2396 static int gpiolib_open(struct inode *inode, struct file *file)
2398 return seq_open(file, &gpiolib_seq_ops);
2401 static const struct file_operations gpiolib_operations = {
2402 .owner = THIS_MODULE,
2403 .open = gpiolib_open,
2405 .llseek = seq_lseek,
2406 .release = seq_release,
2409 static int __init gpiolib_debugfs_init(void)
2411 /* /sys/kernel/debug/gpio */
2412 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2413 NULL, NULL, &gpiolib_operations);
2416 subsys_initcall(gpiolib_debugfs_init);
2418 #endif /* DEBUG_FS */