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 * This lock class tells lockdep that GPIO irqs are in a different
467 * category than their parents, so it won't report false recursion.
469 static struct lock_class_key gpiochip_irq_lock_class;
472 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
473 * @d: the irqdomain used by this irqchip
474 * @irq: the global irq number used by this GPIO irqchip irq
475 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
477 * This function will set up the mapping for a certain IRQ line on a
478 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
479 * stored inside the gpiochip.
481 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
482 irq_hw_number_t hwirq)
484 struct gpio_chip *chip = d->host_data;
486 irq_set_chip_data(irq, chip);
487 irq_set_lockdep_class(irq, &gpiochip_irq_lock_class);
488 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
489 /* Chips that can sleep need nested thread handlers */
490 if (chip->can_sleep && !chip->irq_not_threaded)
491 irq_set_nested_thread(irq, 1);
492 irq_set_noprobe(irq);
495 * No set-up of the hardware will happen if IRQ_TYPE_NONE
496 * is passed as default type.
498 if (chip->irq_default_type != IRQ_TYPE_NONE)
499 irq_set_irq_type(irq, chip->irq_default_type);
504 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
506 struct gpio_chip *chip = d->host_data;
509 irq_set_nested_thread(irq, 0);
510 irq_set_chip_and_handler(irq, NULL, NULL);
511 irq_set_chip_data(irq, NULL);
514 static const struct irq_domain_ops gpiochip_domain_ops = {
515 .map = gpiochip_irq_map,
516 .unmap = gpiochip_irq_unmap,
517 /* Virtually all GPIO irqchips are twocell:ed */
518 .xlate = irq_domain_xlate_twocell,
521 static int gpiochip_irq_reqres(struct irq_data *d)
523 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
525 if (!try_module_get(chip->owner))
528 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
530 "unable to lock HW IRQ %lu for IRQ\n",
532 module_put(chip->owner);
538 static void gpiochip_irq_relres(struct irq_data *d)
540 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
542 gpiochip_unlock_as_irq(chip, d->hwirq);
543 module_put(chip->owner);
546 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
548 return irq_find_mapping(chip->irqdomain, offset);
552 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
553 * @gpiochip: the gpiochip to remove the irqchip from
555 * This is called only from gpiochip_remove()
557 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
561 acpi_gpiochip_free_interrupts(gpiochip);
563 if (gpiochip->irq_parent) {
564 irq_set_chained_handler(gpiochip->irq_parent, NULL);
565 irq_set_handler_data(gpiochip->irq_parent, NULL);
568 /* Remove all IRQ mappings and delete the domain */
569 if (gpiochip->irqdomain) {
570 for (offset = 0; offset < gpiochip->ngpio; offset++)
572 irq_find_mapping(gpiochip->irqdomain, offset));
573 irq_domain_remove(gpiochip->irqdomain);
576 if (gpiochip->irqchip) {
577 gpiochip->irqchip->irq_request_resources = NULL;
578 gpiochip->irqchip->irq_release_resources = NULL;
579 gpiochip->irqchip = NULL;
584 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
585 * @gpiochip: the gpiochip to add the irqchip to
586 * @irqchip: the irqchip to add to the gpiochip
587 * @first_irq: if not dynamically assigned, the base (first) IRQ to
588 * allocate gpiochip irqs from
589 * @handler: the irq handler to use (often a predefined irq core function)
590 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
591 * to have the core avoid setting up any default type in the hardware.
593 * This function closely associates a certain irqchip with a certain
594 * gpiochip, providing an irq domain to translate the local IRQs to
595 * global irqs in the gpiolib core, and making sure that the gpiochip
596 * is passed as chip data to all related functions. Driver callbacks
597 * need to use container_of() to get their local state containers back
598 * from the gpiochip passed as chip data. An irqdomain will be stored
599 * in the gpiochip that shall be used by the driver to handle IRQ number
600 * translation. The gpiochip will need to be initialized and registered
601 * before calling this function.
603 * This function will handle two cell:ed simple IRQs and assumes all
604 * the pins on the gpiochip can generate a unique IRQ. Everything else
605 * need to be open coded.
607 int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
608 struct irq_chip *irqchip,
609 unsigned int first_irq,
610 irq_flow_handler_t handler,
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->irqdomain = irq_domain_add_simple(of_node,
638 gpiochip->ngpio, first_irq,
639 &gpiochip_domain_ops, gpiochip);
640 if (!gpiochip->irqdomain) {
641 gpiochip->irqchip = NULL;
644 irqchip->irq_request_resources = gpiochip_irq_reqres;
645 irqchip->irq_release_resources = gpiochip_irq_relres;
648 * Prepare the mapping since the irqchip shall be orthogonal to
649 * any gpiochip calls. If the first_irq was zero, this is
650 * necessary to allocate descriptors for all IRQs.
652 for (offset = 0; offset < gpiochip->ngpio; offset++) {
653 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
656 * Store the base into the gpiochip to be used when
657 * unmapping the irqs.
659 gpiochip->irq_base = irq_base;
662 acpi_gpiochip_request_interrupts(gpiochip);
666 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
668 #else /* CONFIG_GPIOLIB_IRQCHIP */
670 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
672 #endif /* CONFIG_GPIOLIB_IRQCHIP */
674 #ifdef CONFIG_PINCTRL
677 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
678 * @chip: the gpiochip to add the range for
679 * @pctldev: the pin controller to map to
680 * @gpio_offset: the start offset in the current gpio_chip number space
681 * @pin_group: name of the pin group inside the pin controller
683 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
684 struct pinctrl_dev *pctldev,
685 unsigned int gpio_offset, const char *pin_group)
687 struct gpio_pin_range *pin_range;
690 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
692 chip_err(chip, "failed to allocate pin ranges\n");
696 /* Use local offset as range ID */
697 pin_range->range.id = gpio_offset;
698 pin_range->range.gc = chip;
699 pin_range->range.name = chip->label;
700 pin_range->range.base = chip->base + gpio_offset;
701 pin_range->pctldev = pctldev;
703 ret = pinctrl_get_group_pins(pctldev, pin_group,
704 &pin_range->range.pins,
705 &pin_range->range.npins);
711 pinctrl_add_gpio_range(pctldev, &pin_range->range);
713 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
714 gpio_offset, gpio_offset + pin_range->range.npins - 1,
715 pinctrl_dev_get_devname(pctldev), pin_group);
717 list_add_tail(&pin_range->node, &chip->pin_ranges);
721 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
724 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
725 * @chip: the gpiochip to add the range for
726 * @pinctrl_name: the dev_name() of the pin controller to map to
727 * @gpio_offset: the start offset in the current gpio_chip number space
728 * @pin_offset: the start offset in the pin controller number space
729 * @npins: the number of pins from the offset of each pin space (GPIO and
730 * pin controller) to accumulate in this range
732 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
733 unsigned int gpio_offset, unsigned int pin_offset,
736 struct gpio_pin_range *pin_range;
739 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
741 chip_err(chip, "failed to allocate pin ranges\n");
745 /* Use local offset as range ID */
746 pin_range->range.id = gpio_offset;
747 pin_range->range.gc = chip;
748 pin_range->range.name = chip->label;
749 pin_range->range.base = chip->base + gpio_offset;
750 pin_range->range.pin_base = pin_offset;
751 pin_range->range.npins = npins;
752 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
754 if (IS_ERR(pin_range->pctldev)) {
755 ret = PTR_ERR(pin_range->pctldev);
756 chip_err(chip, "could not create pin range\n");
760 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
761 gpio_offset, gpio_offset + npins - 1,
763 pin_offset, pin_offset + npins - 1);
765 list_add_tail(&pin_range->node, &chip->pin_ranges);
769 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
772 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
773 * @chip: the chip to remove all the mappings for
775 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
777 struct gpio_pin_range *pin_range, *tmp;
779 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
780 list_del(&pin_range->node);
781 pinctrl_remove_gpio_range(pin_range->pctldev,
786 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
788 #endif /* CONFIG_PINCTRL */
790 /* These "optional" allocation calls help prevent drivers from stomping
791 * on each other, and help provide better diagnostics in debugfs.
792 * They're called even less than the "set direction" calls.
794 static int __gpiod_request(struct gpio_desc *desc, const char *label)
796 struct gpio_chip *chip = desc->chip;
800 spin_lock_irqsave(&gpio_lock, flags);
802 /* NOTE: gpio_request() can be called in early boot,
803 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
806 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
807 desc_set_label(desc, label ? : "?");
815 /* chip->request may sleep */
816 spin_unlock_irqrestore(&gpio_lock, flags);
817 status = chip->request(chip, gpio_chip_hwgpio(desc));
818 spin_lock_irqsave(&gpio_lock, flags);
821 desc_set_label(desc, NULL);
822 clear_bit(FLAG_REQUESTED, &desc->flags);
826 if (chip->get_direction) {
827 /* chip->get_direction may sleep */
828 spin_unlock_irqrestore(&gpio_lock, flags);
829 gpiod_get_direction(desc);
830 spin_lock_irqsave(&gpio_lock, flags);
833 spin_unlock_irqrestore(&gpio_lock, flags);
837 int gpiod_request(struct gpio_desc *desc, const char *label)
839 int status = -EPROBE_DEFER;
840 struct gpio_chip *chip;
843 pr_warn("%s: invalid GPIO\n", __func__);
851 if (try_module_get(chip->owner)) {
852 status = __gpiod_request(desc, label);
854 module_put(chip->owner);
859 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
864 static bool __gpiod_free(struct gpio_desc *desc)
868 struct gpio_chip *chip;
872 gpiod_unexport(desc);
874 spin_lock_irqsave(&gpio_lock, flags);
877 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
879 spin_unlock_irqrestore(&gpio_lock, flags);
880 might_sleep_if(chip->can_sleep);
881 chip->free(chip, gpio_chip_hwgpio(desc));
882 spin_lock_irqsave(&gpio_lock, flags);
884 desc_set_label(desc, NULL);
885 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
886 clear_bit(FLAG_REQUESTED, &desc->flags);
887 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
888 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
889 clear_bit(FLAG_IS_HOGGED, &desc->flags);
893 spin_unlock_irqrestore(&gpio_lock, flags);
897 void gpiod_free(struct gpio_desc *desc)
899 if (desc && __gpiod_free(desc))
900 module_put(desc->chip->owner);
902 WARN_ON(extra_checks);
906 * gpiochip_is_requested - return string iff signal was requested
907 * @chip: controller managing the signal
908 * @offset: of signal within controller's 0..(ngpio - 1) range
910 * Returns NULL if the GPIO is not currently requested, else a string.
911 * The string returned is the label passed to gpio_request(); if none has been
912 * passed it is a meaningless, non-NULL constant.
914 * This function is for use by GPIO controller drivers. The label can
915 * help with diagnostics, and knowing that the signal is used as a GPIO
916 * can help avoid accidentally multiplexing it to another controller.
918 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
920 struct gpio_desc *desc;
922 if (!GPIO_OFFSET_VALID(chip, offset))
925 desc = &chip->desc[offset];
927 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
931 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
934 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
935 * @desc: GPIO descriptor to request
936 * @label: label for the GPIO
938 * Function allows GPIO chip drivers to request and use their own GPIO
939 * descriptors via gpiolib API. Difference to gpiod_request() is that this
940 * function will not increase reference count of the GPIO chip module. This
941 * allows the GPIO chip module to be unloaded as needed (we assume that the
942 * GPIO chip driver handles freeing the GPIOs it has requested).
944 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
947 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
951 chip_err(chip, "failed to get GPIO descriptor\n");
955 err = __gpiod_request(desc, label);
961 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
964 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
965 * @desc: GPIO descriptor to free
967 * Function frees the given GPIO requested previously with
968 * gpiochip_request_own_desc().
970 void gpiochip_free_own_desc(struct gpio_desc *desc)
975 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
977 /* Drivers MUST set GPIO direction before making get/set calls. In
978 * some cases this is done in early boot, before IRQs are enabled.
980 * As a rule these aren't called more than once (except for drivers
981 * using the open-drain emulation idiom) so these are natural places
982 * to accumulate extra debugging checks. Note that we can't (yet)
983 * rely on gpio_request() having been called beforehand.
987 * gpiod_direction_input - set the GPIO direction to input
988 * @desc: GPIO to set to input
990 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
991 * be called safely on it.
993 * Return 0 in case of success, else an error code.
995 int gpiod_direction_input(struct gpio_desc *desc)
997 struct gpio_chip *chip;
998 int status = -EINVAL;
1000 if (!desc || !desc->chip) {
1001 pr_warn("%s: invalid GPIO\n", __func__);
1006 if (!chip->get || !chip->direction_input) {
1008 "%s: missing get() or direction_input() operations\n",
1013 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1015 clear_bit(FLAG_IS_OUT, &desc->flags);
1017 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1021 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1023 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1025 struct gpio_chip *chip;
1026 int status = -EINVAL;
1028 /* GPIOs used for IRQs shall not be set as output */
1029 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1031 "%s: tried to set a GPIO tied to an IRQ as output\n",
1036 /* Open drain pin should not be driven to 1 */
1037 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1038 return gpiod_direction_input(desc);
1040 /* Open source pin should not be driven to 0 */
1041 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1042 return gpiod_direction_input(desc);
1045 if (!chip->set || !chip->direction_output) {
1047 "%s: missing set() or direction_output() operations\n",
1052 status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
1054 set_bit(FLAG_IS_OUT, &desc->flags);
1055 trace_gpio_value(desc_to_gpio(desc), 0, value);
1056 trace_gpio_direction(desc_to_gpio(desc), 0, status);
1061 * gpiod_direction_output_raw - set the GPIO direction to output
1062 * @desc: GPIO to set to output
1063 * @value: initial output value of the GPIO
1065 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1066 * be called safely on it. The initial value of the output must be specified
1067 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1069 * Return 0 in case of success, else an error code.
1071 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1073 if (!desc || !desc->chip) {
1074 pr_warn("%s: invalid GPIO\n", __func__);
1077 return _gpiod_direction_output_raw(desc, value);
1079 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1082 * gpiod_direction_output - set the GPIO direction to output
1083 * @desc: GPIO to set to output
1084 * @value: initial output value of the GPIO
1086 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1087 * be called safely on it. The initial value of the output must be specified
1088 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1091 * Return 0 in case of success, else an error code.
1093 int gpiod_direction_output(struct gpio_desc *desc, int value)
1095 if (!desc || !desc->chip) {
1096 pr_warn("%s: invalid GPIO\n", __func__);
1099 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1101 return _gpiod_direction_output_raw(desc, value);
1103 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1106 * gpiod_set_debounce - sets @debounce time for a @gpio
1107 * @gpio: the gpio to set debounce time
1108 * @debounce: debounce time is microseconds
1110 * returns -ENOTSUPP if the controller does not support setting
1113 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1115 struct gpio_chip *chip;
1117 if (!desc || !desc->chip) {
1118 pr_warn("%s: invalid GPIO\n", __func__);
1123 if (!chip->set || !chip->set_debounce) {
1125 "%s: missing set() or set_debounce() operations\n",
1130 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1132 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1135 * gpiod_is_active_low - test whether a GPIO is active-low or not
1136 * @desc: the gpio descriptor to test
1138 * Returns 1 if the GPIO is active-low, 0 otherwise.
1140 int gpiod_is_active_low(const struct gpio_desc *desc)
1142 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1144 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1146 /* I/O calls are only valid after configuration completed; the relevant
1147 * "is this a valid GPIO" error checks should already have been done.
1149 * "Get" operations are often inlinable as reading a pin value register,
1150 * and masking the relevant bit in that register.
1152 * When "set" operations are inlinable, they involve writing that mask to
1153 * one register to set a low value, or a different register to set it high.
1154 * Otherwise locking is needed, so there may be little value to inlining.
1156 *------------------------------------------------------------------------
1158 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1159 * have requested the GPIO. That can include implicit requesting by
1160 * a direction setting call. Marking a gpio as requested locks its chip
1161 * in memory, guaranteeing that these table lookups need no more locking
1162 * and that gpiochip_remove() will fail.
1164 * REVISIT when debugging, consider adding some instrumentation to ensure
1165 * that the GPIO was actually requested.
1168 static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
1170 struct gpio_chip *chip;
1175 offset = gpio_chip_hwgpio(desc);
1176 value = chip->get ? chip->get(chip, offset) : false;
1177 trace_gpio_value(desc_to_gpio(desc), 1, value);
1182 * gpiod_get_raw_value() - return a gpio's raw value
1183 * @desc: gpio whose value will be returned
1185 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1186 * its ACTIVE_LOW status.
1188 * This function should be called from contexts where we cannot sleep, and will
1189 * complain if the GPIO chip functions potentially sleep.
1191 int gpiod_get_raw_value(const struct gpio_desc *desc)
1195 /* Should be using gpio_get_value_cansleep() */
1196 WARN_ON(desc->chip->can_sleep);
1197 return _gpiod_get_raw_value(desc);
1199 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1202 * gpiod_get_value() - return a gpio's value
1203 * @desc: gpio whose value will be returned
1205 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1208 * This function should be called from contexts where we cannot sleep, and will
1209 * complain if the GPIO chip functions potentially sleep.
1211 int gpiod_get_value(const struct gpio_desc *desc)
1216 /* Should be using gpio_get_value_cansleep() */
1217 WARN_ON(desc->chip->can_sleep);
1219 value = _gpiod_get_raw_value(desc);
1220 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1225 EXPORT_SYMBOL_GPL(gpiod_get_value);
1228 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1229 * @desc: gpio descriptor whose state need to be set.
1230 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1232 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1235 struct gpio_chip *chip = desc->chip;
1236 int offset = gpio_chip_hwgpio(desc);
1239 err = chip->direction_input(chip, offset);
1241 clear_bit(FLAG_IS_OUT, &desc->flags);
1243 err = chip->direction_output(chip, offset, 0);
1245 set_bit(FLAG_IS_OUT, &desc->flags);
1247 trace_gpio_direction(desc_to_gpio(desc), value, err);
1250 "%s: Error in set_value for open drain err %d\n",
1255 * _gpio_set_open_source_value() - Set the open source gpio's value.
1256 * @desc: gpio descriptor whose state need to be set.
1257 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1259 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1262 struct gpio_chip *chip = desc->chip;
1263 int offset = gpio_chip_hwgpio(desc);
1266 err = chip->direction_output(chip, offset, 1);
1268 set_bit(FLAG_IS_OUT, &desc->flags);
1270 err = chip->direction_input(chip, offset);
1272 clear_bit(FLAG_IS_OUT, &desc->flags);
1274 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1277 "%s: Error in set_value for open source err %d\n",
1281 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1283 struct gpio_chip *chip;
1286 trace_gpio_value(desc_to_gpio(desc), 0, value);
1287 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1288 _gpio_set_open_drain_value(desc, value);
1289 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1290 _gpio_set_open_source_value(desc, value);
1292 chip->set(chip, gpio_chip_hwgpio(desc), value);
1296 * set multiple outputs on the same chip;
1297 * use the chip's set_multiple function if available;
1298 * otherwise set the outputs sequentially;
1299 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1300 * defines which outputs are to be changed
1301 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1302 * defines the values the outputs specified by mask are to be set to
1304 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1305 unsigned long *mask, unsigned long *bits)
1307 if (chip->set_multiple) {
1308 chip->set_multiple(chip, mask, bits);
1311 for (i = 0; i < chip->ngpio; i++) {
1312 if (mask[BIT_WORD(i)] == 0) {
1313 /* no more set bits in this mask word;
1314 * skip ahead to the next word */
1315 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1318 /* set outputs if the corresponding mask bit is set */
1319 if (__test_and_clear_bit(i, mask))
1320 chip->set(chip, i, test_bit(i, bits));
1325 static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
1326 unsigned int array_size,
1327 struct gpio_desc **desc_array,
1332 while (i < array_size) {
1333 struct gpio_chip *chip = desc_array[i]->chip;
1334 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1335 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1339 WARN_ON(chip->can_sleep);
1341 memset(mask, 0, sizeof(mask));
1343 struct gpio_desc *desc = desc_array[i];
1344 int hwgpio = gpio_chip_hwgpio(desc);
1345 int value = value_array[i];
1347 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1349 trace_gpio_value(desc_to_gpio(desc), 0, value);
1351 * collect all normal outputs belonging to the same chip
1352 * open drain and open source outputs are set individually
1354 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1355 _gpio_set_open_drain_value(desc, value);
1356 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1357 _gpio_set_open_source_value(desc, value);
1359 __set_bit(hwgpio, mask);
1361 __set_bit(hwgpio, bits);
1363 __clear_bit(hwgpio, bits);
1367 } while ((i < array_size) && (desc_array[i]->chip == chip));
1368 /* push collected bits to outputs */
1370 gpio_chip_set_multiple(chip, mask, bits);
1375 * gpiod_set_raw_value() - assign a gpio's raw value
1376 * @desc: gpio whose value will be assigned
1377 * @value: value to assign
1379 * Set the raw value of the GPIO, i.e. the value of its physical line without
1380 * regard for its ACTIVE_LOW status.
1382 * This function should be called from contexts where we cannot sleep, and will
1383 * complain if the GPIO chip functions potentially sleep.
1385 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1389 /* Should be using gpio_set_value_cansleep() */
1390 WARN_ON(desc->chip->can_sleep);
1391 _gpiod_set_raw_value(desc, value);
1393 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1396 * gpiod_set_value() - assign a gpio's value
1397 * @desc: gpio whose value will be assigned
1398 * @value: value to assign
1400 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1403 * This function should be called from contexts where we cannot sleep, and will
1404 * complain if the GPIO chip functions potentially sleep.
1406 void gpiod_set_value(struct gpio_desc *desc, int value)
1410 /* Should be using gpio_set_value_cansleep() */
1411 WARN_ON(desc->chip->can_sleep);
1412 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1414 _gpiod_set_raw_value(desc, value);
1416 EXPORT_SYMBOL_GPL(gpiod_set_value);
1419 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1420 * @array_size: number of elements in the descriptor / value arrays
1421 * @desc_array: array of GPIO descriptors whose values will be assigned
1422 * @value_array: array of values to assign
1424 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1425 * without regard for their ACTIVE_LOW status.
1427 * This function should be called from contexts where we cannot sleep, and will
1428 * complain if the GPIO chip functions potentially sleep.
1430 void gpiod_set_raw_array_value(unsigned int array_size,
1431 struct gpio_desc **desc_array, int *value_array)
1435 gpiod_set_array_value_priv(true, false, array_size, desc_array,
1438 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
1441 * gpiod_set_array_value() - assign values to an array of GPIOs
1442 * @array_size: number of elements in the descriptor / value arrays
1443 * @desc_array: array of GPIO descriptors whose values will be assigned
1444 * @value_array: array of values to assign
1446 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1449 * This function should be called from contexts where we cannot sleep, and will
1450 * complain if the GPIO chip functions potentially sleep.
1452 void gpiod_set_array_value(unsigned int array_size,
1453 struct gpio_desc **desc_array, int *value_array)
1457 gpiod_set_array_value_priv(false, false, array_size, desc_array,
1460 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
1463 * gpiod_cansleep() - report whether gpio value access may sleep
1464 * @desc: gpio to check
1467 int gpiod_cansleep(const struct gpio_desc *desc)
1471 return desc->chip->can_sleep;
1473 EXPORT_SYMBOL_GPL(gpiod_cansleep);
1476 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1477 * @desc: gpio whose IRQ will be returned (already requested)
1479 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1482 int gpiod_to_irq(const struct gpio_desc *desc)
1484 struct gpio_chip *chip;
1490 offset = gpio_chip_hwgpio(desc);
1491 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
1493 EXPORT_SYMBOL_GPL(gpiod_to_irq);
1496 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1497 * @chip: the chip the GPIO to lock belongs to
1498 * @offset: the offset of the GPIO to lock as IRQ
1500 * This is used directly by GPIO drivers that want to lock down
1501 * a certain GPIO line to be used for IRQs.
1503 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
1505 if (offset >= chip->ngpio)
1508 if (test_bit(FLAG_IS_OUT, &chip->desc[offset].flags)) {
1510 "%s: tried to flag a GPIO set as output for IRQ\n",
1515 set_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1518 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
1521 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1522 * @chip: the chip the GPIO to lock belongs to
1523 * @offset: the offset of the GPIO to lock as IRQ
1525 * This is used directly by GPIO drivers that want to indicate
1526 * that a certain GPIO is no longer used exclusively for IRQ.
1528 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
1530 if (offset >= chip->ngpio)
1533 clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
1535 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
1538 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1539 * @desc: gpio whose value will be returned
1541 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1542 * its ACTIVE_LOW status.
1544 * This function is to be called from contexts that can sleep.
1546 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
1548 might_sleep_if(extra_checks);
1551 return _gpiod_get_raw_value(desc);
1553 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
1556 * gpiod_get_value_cansleep() - return a gpio's value
1557 * @desc: gpio whose value will be returned
1559 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1562 * This function is to be called from contexts that can sleep.
1564 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
1568 might_sleep_if(extra_checks);
1572 value = _gpiod_get_raw_value(desc);
1573 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1578 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
1581 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
1582 * @desc: gpio whose value will be assigned
1583 * @value: value to assign
1585 * Set the raw value of the GPIO, i.e. the value of its physical line without
1586 * regard for its ACTIVE_LOW status.
1588 * This function is to be called from contexts that can sleep.
1590 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
1592 might_sleep_if(extra_checks);
1595 _gpiod_set_raw_value(desc, value);
1597 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
1600 * gpiod_set_value_cansleep() - assign a gpio's value
1601 * @desc: gpio whose value will be assigned
1602 * @value: value to assign
1604 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1607 * This function is to be called from contexts that can sleep.
1609 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
1611 might_sleep_if(extra_checks);
1615 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1617 _gpiod_set_raw_value(desc, value);
1619 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
1622 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
1623 * @array_size: number of elements in the descriptor / value arrays
1624 * @desc_array: array of GPIO descriptors whose values will be assigned
1625 * @value_array: array of values to assign
1627 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1628 * without regard for their ACTIVE_LOW status.
1630 * This function is to be called from contexts that can sleep.
1632 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
1633 struct gpio_desc **desc_array,
1636 might_sleep_if(extra_checks);
1639 gpiod_set_array_value_priv(true, true, array_size, desc_array,
1642 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
1645 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
1646 * @array_size: number of elements in the descriptor / value arrays
1647 * @desc_array: array of GPIO descriptors whose values will be assigned
1648 * @value_array: array of values to assign
1650 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1653 * This function is to be called from contexts that can sleep.
1655 void gpiod_set_array_value_cansleep(unsigned int array_size,
1656 struct gpio_desc **desc_array,
1659 might_sleep_if(extra_checks);
1662 gpiod_set_array_value_priv(false, true, array_size, desc_array,
1665 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
1668 * gpiod_add_lookup_table() - register GPIO device consumers
1669 * @table: table of consumers to register
1671 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
1673 mutex_lock(&gpio_lookup_lock);
1675 list_add_tail(&table->list, &gpio_lookup_list);
1677 mutex_unlock(&gpio_lookup_lock);
1680 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
1682 enum gpio_lookup_flags *flags)
1684 char prop_name[32]; /* 32 is max size of property name */
1685 enum of_gpio_flags of_flags;
1686 struct gpio_desc *desc;
1689 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1691 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
1694 snprintf(prop_name, sizeof(prop_name), "%s",
1697 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
1699 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1706 if (of_flags & OF_GPIO_ACTIVE_LOW)
1707 *flags |= GPIO_ACTIVE_LOW;
1712 static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
1714 enum gpio_lookup_flags *flags)
1716 struct acpi_device *adev = ACPI_COMPANION(dev);
1717 struct acpi_gpio_info info;
1718 struct gpio_desc *desc;
1722 /* Try first from _DSD */
1723 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1724 if (con_id && strcmp(con_id, "gpios")) {
1725 snprintf(propname, sizeof(propname), "%s-%s",
1726 con_id, gpio_suffixes[i]);
1728 snprintf(propname, sizeof(propname), "%s",
1732 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
1733 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
1737 /* Then from plain _CRS GPIOs */
1739 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
1744 if (info.active_low)
1745 *flags |= GPIO_ACTIVE_LOW;
1750 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
1752 const char *dev_id = dev ? dev_name(dev) : NULL;
1753 struct gpiod_lookup_table *table;
1755 mutex_lock(&gpio_lookup_lock);
1757 list_for_each_entry(table, &gpio_lookup_list, list) {
1758 if (table->dev_id && dev_id) {
1760 * Valid strings on both ends, must be identical to have
1763 if (!strcmp(table->dev_id, dev_id))
1767 * One of the pointers is NULL, so both must be to have
1770 if (dev_id == table->dev_id)
1777 mutex_unlock(&gpio_lookup_lock);
1781 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
1783 enum gpio_lookup_flags *flags)
1785 struct gpio_desc *desc = ERR_PTR(-ENOENT);
1786 struct gpiod_lookup_table *table;
1787 struct gpiod_lookup *p;
1789 table = gpiod_find_lookup_table(dev);
1793 for (p = &table->table[0]; p->chip_label; p++) {
1794 struct gpio_chip *chip;
1796 /* idx must always match exactly */
1800 /* If the lookup entry has a con_id, require exact match */
1801 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
1804 chip = find_chip_by_name(p->chip_label);
1807 dev_err(dev, "cannot find GPIO chip %s\n",
1809 return ERR_PTR(-ENODEV);
1812 if (chip->ngpio <= p->chip_hwnum) {
1814 "requested GPIO %d is out of range [0..%d] for chip %s\n",
1815 idx, chip->ngpio, chip->label);
1816 return ERR_PTR(-EINVAL);
1819 desc = gpiochip_get_desc(chip, p->chip_hwnum);
1828 static int dt_gpio_count(struct device *dev, const char *con_id)
1834 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1836 snprintf(propname, sizeof(propname), "%s-%s",
1837 con_id, gpio_suffixes[i]);
1839 snprintf(propname, sizeof(propname), "%s",
1842 ret = of_gpio_named_count(dev->of_node, propname);
1849 static int platform_gpio_count(struct device *dev, const char *con_id)
1851 struct gpiod_lookup_table *table;
1852 struct gpiod_lookup *p;
1853 unsigned int count = 0;
1855 table = gpiod_find_lookup_table(dev);
1859 for (p = &table->table[0]; p->chip_label; p++) {
1860 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
1861 (!con_id && !p->con_id))
1871 * gpiod_count - return the number of GPIOs associated with a device / function
1872 * or -ENOENT if no GPIO has been assigned to the requested function
1873 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1874 * @con_id: function within the GPIO consumer
1876 int gpiod_count(struct device *dev, const char *con_id)
1878 int count = -ENOENT;
1880 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
1881 count = dt_gpio_count(dev, con_id);
1882 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
1883 count = acpi_gpio_count(dev, con_id);
1886 count = platform_gpio_count(dev, con_id);
1890 EXPORT_SYMBOL_GPL(gpiod_count);
1893 * gpiod_get - obtain a GPIO for a given GPIO function
1894 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1895 * @con_id: function within the GPIO consumer
1896 * @flags: optional GPIO initialization flags
1898 * Return the GPIO descriptor corresponding to the function con_id of device
1899 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
1900 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
1902 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
1903 enum gpiod_flags flags)
1905 return gpiod_get_index(dev, con_id, 0, flags);
1907 EXPORT_SYMBOL_GPL(gpiod_get);
1910 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
1911 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1912 * @con_id: function within the GPIO consumer
1913 * @flags: optional GPIO initialization flags
1915 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
1916 * the requested function it will return NULL. This is convenient for drivers
1917 * that need to handle optional GPIOs.
1919 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
1921 enum gpiod_flags flags)
1923 return gpiod_get_index_optional(dev, con_id, 0, flags);
1925 EXPORT_SYMBOL_GPL(gpiod_get_optional);
1929 * gpiod_configure_flags - helper function to configure a given GPIO
1930 * @desc: gpio whose value will be assigned
1931 * @con_id: function within the GPIO consumer
1932 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
1934 * @dflags: gpiod_flags - optional GPIO initialization flags
1936 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
1937 * requested function and/or index, or another IS_ERR() code if an error
1938 * occurred while trying to acquire the GPIO.
1940 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
1941 unsigned long lflags, enum gpiod_flags dflags)
1945 if (lflags & GPIO_ACTIVE_LOW)
1946 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
1947 if (lflags & GPIO_OPEN_DRAIN)
1948 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
1949 if (lflags & GPIO_OPEN_SOURCE)
1950 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
1952 /* No particular flag request, return here... */
1953 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
1954 pr_debug("no flags found for %s\n", con_id);
1959 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
1960 status = gpiod_direction_output(desc,
1961 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
1963 status = gpiod_direction_input(desc);
1969 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
1970 * @dev: GPIO consumer, can be NULL for system-global GPIOs
1971 * @con_id: function within the GPIO consumer
1972 * @idx: index of the GPIO to obtain in the consumer
1973 * @flags: optional GPIO initialization flags
1975 * This variant of gpiod_get() allows to access GPIOs other than the first
1976 * defined one for functions that define several GPIOs.
1978 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
1979 * requested function and/or index, or another IS_ERR() code if an error
1980 * occurred while trying to acquire the GPIO.
1982 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
1985 enum gpiod_flags flags)
1987 struct gpio_desc *desc = NULL;
1989 enum gpio_lookup_flags lookupflags = 0;
1991 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
1994 /* Using device tree? */
1995 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
1996 dev_dbg(dev, "using device tree for GPIO lookup\n");
1997 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
1998 } else if (ACPI_COMPANION(dev)) {
1999 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2000 desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
2005 * Either we are not using DT or ACPI, or their lookup did not return
2006 * a result. In that case, use platform lookup as a fallback.
2008 if (!desc || desc == ERR_PTR(-ENOENT)) {
2009 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2010 desc = gpiod_find(dev, con_id, idx, &lookupflags);
2014 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2018 status = gpiod_request(desc, con_id);
2020 return ERR_PTR(status);
2022 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
2024 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2026 return ERR_PTR(status);
2031 EXPORT_SYMBOL_GPL(gpiod_get_index);
2034 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2035 * @fwnode: handle of the firmware node
2036 * @propname: name of the firmware property representing the GPIO
2038 * This function can be used for drivers that get their configuration
2041 * Function properly finds the corresponding GPIO using whatever is the
2042 * underlying firmware interface and then makes sure that the GPIO
2043 * descriptor is requested before it is returned to the caller.
2045 * In case of error an ERR_PTR() is returned.
2047 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2048 const char *propname)
2050 struct gpio_desc *desc = ERR_PTR(-ENODEV);
2051 bool active_low = false;
2055 return ERR_PTR(-EINVAL);
2057 if (is_of_node(fwnode)) {
2058 enum of_gpio_flags flags;
2060 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2063 active_low = flags & OF_GPIO_ACTIVE_LOW;
2064 } else if (is_acpi_node(fwnode)) {
2065 struct acpi_gpio_info info;
2067 desc = acpi_get_gpiod_by_index(to_acpi_node(fwnode), propname, 0,
2070 active_low = info.active_low;
2076 ret = gpiod_request(desc, NULL);
2078 return ERR_PTR(ret);
2080 /* Only value flag can be set from both DT and ACPI is active_low */
2082 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2086 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2089 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2091 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2092 * @con_id: function within the GPIO consumer
2093 * @index: index of the GPIO to obtain in the consumer
2094 * @flags: optional GPIO initialization flags
2096 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2097 * specified index was assigned to the requested function it will return NULL.
2098 * This is convenient for drivers that need to handle optional GPIOs.
2100 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2103 enum gpiod_flags flags)
2105 struct gpio_desc *desc;
2107 desc = gpiod_get_index(dev, con_id, index, flags);
2109 if (PTR_ERR(desc) == -ENOENT)
2115 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2118 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2119 * @desc: gpio whose value will be assigned
2120 * @name: gpio line name
2121 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2123 * @dflags: gpiod_flags - optional GPIO initialization flags
2125 int gpiod_hog(struct gpio_desc *desc, const char *name,
2126 unsigned long lflags, enum gpiod_flags dflags)
2128 struct gpio_chip *chip;
2129 struct gpio_desc *local_desc;
2133 chip = gpiod_to_chip(desc);
2134 hwnum = gpio_chip_hwgpio(desc);
2136 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2137 if (IS_ERR(local_desc)) {
2138 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2139 name, chip->label, hwnum);
2140 return PTR_ERR(local_desc);
2143 status = gpiod_configure_flags(desc, name, lflags, dflags);
2145 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2146 name, chip->label, hwnum);
2147 gpiochip_free_own_desc(desc);
2151 /* Mark GPIO as hogged so it can be identified and removed later */
2152 set_bit(FLAG_IS_HOGGED, &desc->flags);
2154 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2155 desc_to_gpio(desc), name,
2156 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2157 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2158 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2164 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2165 * @chip: gpio chip to act on
2167 * This is only used by of_gpiochip_remove to free hogged gpios
2169 static void gpiochip_free_hogs(struct gpio_chip *chip)
2173 for (id = 0; id < chip->ngpio; id++) {
2174 if (test_bit(FLAG_IS_HOGGED, &chip->desc[id].flags))
2175 gpiochip_free_own_desc(&chip->desc[id]);
2180 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2181 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2182 * @con_id: function within the GPIO consumer
2183 * @flags: optional GPIO initialization flags
2185 * This function acquires all the GPIOs defined under a given function.
2187 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2188 * no GPIO has been assigned to the requested function, or another IS_ERR()
2189 * code if an error occurred while trying to acquire the GPIOs.
2191 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2193 enum gpiod_flags flags)
2195 struct gpio_desc *desc;
2196 struct gpio_descs *descs;
2199 count = gpiod_count(dev, con_id);
2201 return ERR_PTR(count);
2203 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2206 return ERR_PTR(-ENOMEM);
2208 for (descs->ndescs = 0; descs->ndescs < count; ) {
2209 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2211 gpiod_put_array(descs);
2212 return ERR_CAST(desc);
2214 descs->desc[descs->ndescs] = desc;
2219 EXPORT_SYMBOL_GPL(gpiod_get_array);
2222 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2224 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2225 * @con_id: function within the GPIO consumer
2226 * @flags: optional GPIO initialization flags
2228 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2229 * assigned to the requested function it will return NULL.
2231 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2233 enum gpiod_flags flags)
2235 struct gpio_descs *descs;
2237 descs = gpiod_get_array(dev, con_id, flags);
2238 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2243 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2246 * gpiod_put - dispose of a GPIO descriptor
2247 * @desc: GPIO descriptor to dispose of
2249 * No descriptor can be used after gpiod_put() has been called on it.
2251 void gpiod_put(struct gpio_desc *desc)
2255 EXPORT_SYMBOL_GPL(gpiod_put);
2258 * gpiod_put_array - dispose of multiple GPIO descriptors
2259 * @descs: struct gpio_descs containing an array of descriptors
2261 void gpiod_put_array(struct gpio_descs *descs)
2265 for (i = 0; i < descs->ndescs; i++)
2266 gpiod_put(descs->desc[i]);
2270 EXPORT_SYMBOL_GPL(gpiod_put_array);
2272 #ifdef CONFIG_DEBUG_FS
2274 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2277 unsigned gpio = chip->base;
2278 struct gpio_desc *gdesc = &chip->desc[0];
2282 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2283 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
2286 gpiod_get_direction(gdesc);
2287 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2288 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2289 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
2291 is_out ? "out" : "in ",
2293 ? (chip->get(chip, i) ? "hi" : "lo")
2295 is_irq ? "IRQ" : " ");
2296 seq_printf(s, "\n");
2300 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2302 unsigned long flags;
2303 struct gpio_chip *chip = NULL;
2304 loff_t index = *pos;
2308 spin_lock_irqsave(&gpio_lock, flags);
2309 list_for_each_entry(chip, &gpio_chips, list)
2311 spin_unlock_irqrestore(&gpio_lock, flags);
2314 spin_unlock_irqrestore(&gpio_lock, flags);
2319 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2321 unsigned long flags;
2322 struct gpio_chip *chip = v;
2325 spin_lock_irqsave(&gpio_lock, flags);
2326 if (list_is_last(&chip->list, &gpio_chips))
2329 ret = list_entry(chip->list.next, struct gpio_chip, list);
2330 spin_unlock_irqrestore(&gpio_lock, flags);
2338 static void gpiolib_seq_stop(struct seq_file *s, void *v)
2342 static int gpiolib_seq_show(struct seq_file *s, void *v)
2344 struct gpio_chip *chip = v;
2347 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2348 chip->base, chip->base + chip->ngpio - 1);
2351 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2354 seq_printf(s, ", %s", chip->label);
2355 if (chip->can_sleep)
2356 seq_printf(s, ", can sleep");
2357 seq_printf(s, ":\n");
2360 chip->dbg_show(s, chip);
2362 gpiolib_dbg_show(s, chip);
2367 static const struct seq_operations gpiolib_seq_ops = {
2368 .start = gpiolib_seq_start,
2369 .next = gpiolib_seq_next,
2370 .stop = gpiolib_seq_stop,
2371 .show = gpiolib_seq_show,
2374 static int gpiolib_open(struct inode *inode, struct file *file)
2376 return seq_open(file, &gpiolib_seq_ops);
2379 static const struct file_operations gpiolib_operations = {
2380 .owner = THIS_MODULE,
2381 .open = gpiolib_open,
2383 .llseek = seq_lseek,
2384 .release = seq_release,
2387 static int __init gpiolib_debugfs_init(void)
2389 /* /sys/kernel/debug/gpio */
2390 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2391 NULL, NULL, &gpiolib_operations);
2394 subsys_initcall(gpiolib_debugfs_init);
2396 #endif /* DEBUG_FS */