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 */