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>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/idr.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <uapi/linux/gpio.h>
27 #define CREATE_TRACE_POINTS
28 #include <trace/events/gpio.h>
30 /* Implementation infrastructure for GPIO interfaces.
32 * The GPIO programming interface allows for inlining speed-critical
33 * get/set operations for common cases, so that access to SOC-integrated
34 * GPIOs can sometimes cost only an instruction or two per bit.
38 /* When debugging, extend minimal trust to callers and platform code.
39 * Also emit diagnostic messages that may help initial bringup, when
40 * board setup or driver bugs are most common.
42 * Otherwise, minimize overhead in what may be bitbanging codepaths.
45 #define extra_checks 1
47 #define extra_checks 0
50 /* Device and char device-related information */
51 static DEFINE_IDA(gpio_ida
);
52 static dev_t gpio_devt
;
53 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
54 static struct bus_type gpio_bus_type
= {
58 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
59 * While any GPIO is requested, its gpio_chip is not removable;
60 * each GPIO's "requested" flag serves as a lock and refcount.
62 DEFINE_SPINLOCK(gpio_lock
);
64 static DEFINE_MUTEX(gpio_lookup_lock
);
65 static LIST_HEAD(gpio_lookup_list
);
66 LIST_HEAD(gpio_devices
);
68 static void gpiochip_free_hogs(struct gpio_chip
*chip
);
69 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
);
72 static inline void desc_set_label(struct gpio_desc
*d
, const char *label
)
78 * Convert a GPIO number to its descriptor
80 struct gpio_desc
*gpio_to_desc(unsigned gpio
)
82 struct gpio_device
*gdev
;
85 spin_lock_irqsave(&gpio_lock
, flags
);
87 list_for_each_entry(gdev
, &gpio_devices
, list
) {
88 if (gdev
->base
<= gpio
&&
89 gdev
->base
+ gdev
->ngpio
> gpio
) {
90 spin_unlock_irqrestore(&gpio_lock
, flags
);
91 return &gdev
->descs
[gpio
- gdev
->base
];
95 spin_unlock_irqrestore(&gpio_lock
, flags
);
97 if (!gpio_is_valid(gpio
))
98 WARN(1, "invalid GPIO %d\n", gpio
);
102 EXPORT_SYMBOL_GPL(gpio_to_desc
);
105 * Get the GPIO descriptor corresponding to the given hw number for this chip.
107 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
110 struct gpio_device
*gdev
= chip
->gpiodev
;
112 if (hwnum
>= gdev
->ngpio
)
113 return ERR_PTR(-EINVAL
);
115 return &gdev
->descs
[hwnum
];
119 * Convert a GPIO descriptor to the integer namespace.
120 * This should disappear in the future but is needed since we still
121 * use GPIO numbers for error messages and sysfs nodes
123 int desc_to_gpio(const struct gpio_desc
*desc
)
125 return desc
->gdev
->base
+ (desc
- &desc
->gdev
->descs
[0]);
127 EXPORT_SYMBOL_GPL(desc_to_gpio
);
131 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
132 * @desc: descriptor to return the chip of
134 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
136 if (!desc
|| !desc
->gdev
|| !desc
->gdev
->chip
)
138 return desc
->gdev
->chip
;
140 EXPORT_SYMBOL_GPL(gpiod_to_chip
);
142 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
143 static int gpiochip_find_base(int ngpio
)
145 struct gpio_device
*gdev
;
146 int base
= ARCH_NR_GPIOS
- ngpio
;
148 list_for_each_entry_reverse(gdev
, &gpio_devices
, list
) {
149 /* found a free space? */
150 if (gdev
->base
+ gdev
->ngpio
<= base
)
153 /* nope, check the space right before the chip */
154 base
= gdev
->base
- ngpio
;
157 if (gpio_is_valid(base
)) {
158 pr_debug("%s: found new base at %d\n", __func__
, base
);
161 pr_err("%s: cannot find free range\n", __func__
);
167 * gpiod_get_direction - return the current direction of a GPIO
168 * @desc: GPIO to get the direction of
170 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
172 * This function may sleep if gpiod_cansleep() is true.
174 int gpiod_get_direction(struct gpio_desc
*desc
)
176 struct gpio_chip
*chip
;
178 int status
= -EINVAL
;
180 chip
= gpiod_to_chip(desc
);
181 offset
= gpio_chip_hwgpio(desc
);
183 if (!chip
->get_direction
)
186 status
= chip
->get_direction(chip
, offset
);
188 /* GPIOF_DIR_IN, or other positive */
190 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
194 set_bit(FLAG_IS_OUT
, &desc
->flags
);
198 EXPORT_SYMBOL_GPL(gpiod_get_direction
);
201 * Add a new chip to the global chips list, keeping the list of chips sorted
202 * by range(means [base, base + ngpio - 1]) order.
204 * Return -EBUSY if the new chip overlaps with some other chip's integer
207 static int gpiodev_add_to_list(struct gpio_device
*gdev
)
209 struct gpio_device
*iterator
;
210 struct gpio_device
*previous
= NULL
;
215 if (list_empty(&gpio_devices
)) {
216 list_add_tail(&gdev
->list
, &gpio_devices
);
220 list_for_each_entry(iterator
, &gpio_devices
, list
) {
221 if (iterator
->base
>= gdev
->base
+ gdev
->ngpio
) {
223 * Iterator is the first GPIO chip so there is no
230 * We found a valid range(means
231 * [base, base + ngpio - 1]) between previous
234 if (previous
->base
+ previous
->ngpio
243 * We are beyond the last chip in the list and iterator now
244 * points to the head.
245 * Let iterator point to the last chip in the list.
248 iterator
= list_last_entry(&gpio_devices
, struct gpio_device
, list
);
249 if (iterator
->base
+ iterator
->ngpio
<= gdev
->base
) {
250 list_add(&gdev
->list
, &iterator
->list
);
255 "GPIO integer space overlap, cannot add chip\n");
259 list_add_tail(&gdev
->list
, &iterator
->list
);
264 * Convert a GPIO name to its descriptor
266 static struct gpio_desc
*gpio_name_to_desc(const char * const name
)
268 struct gpio_device
*gdev
;
271 spin_lock_irqsave(&gpio_lock
, flags
);
273 list_for_each_entry(gdev
, &gpio_devices
, list
) {
276 for (i
= 0; i
!= gdev
->ngpio
; ++i
) {
277 struct gpio_desc
*desc
= &gdev
->descs
[i
];
279 if (!desc
->name
|| !name
)
282 if (!strcmp(desc
->name
, name
)) {
283 spin_unlock_irqrestore(&gpio_lock
, flags
);
289 spin_unlock_irqrestore(&gpio_lock
, flags
);
295 * Takes the names from gc->names and checks if they are all unique. If they
296 * are, they are assigned to their gpio descriptors.
298 * Warning if one of the names is already used for a different GPIO.
300 static int gpiochip_set_desc_names(struct gpio_chip
*gc
)
302 struct gpio_device
*gdev
= gc
->gpiodev
;
308 /* First check all names if they are unique */
309 for (i
= 0; i
!= gc
->ngpio
; ++i
) {
310 struct gpio_desc
*gpio
;
312 gpio
= gpio_name_to_desc(gc
->names
[i
]);
315 "Detected name collision for GPIO name '%s'\n",
319 /* Then add all names to the GPIO descriptors */
320 for (i
= 0; i
!= gc
->ngpio
; ++i
)
321 gdev
->descs
[i
].name
= gc
->names
[i
];
327 * gpio_ioctl() - ioctl handler for the GPIO chardev
329 static long gpio_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
331 struct gpio_device
*gdev
= filp
->private_data
;
332 struct gpio_chip
*chip
= gdev
->chip
;
333 int __user
*ip
= (int __user
*)arg
;
334 struct gpiochip_info chipinfo
;
336 /* We fail any subsequent ioctl():s when the chip is gone */
340 if (cmd
== GPIO_GET_CHIPINFO_IOCTL
) {
341 /* Fill in the struct and pass to userspace */
342 strncpy(chipinfo
.name
, dev_name(&gdev
->dev
),
343 sizeof(chipinfo
.name
));
344 chipinfo
.name
[sizeof(chipinfo
.name
)-1] = '\0';
345 strncpy(chipinfo
.label
, gdev
->label
,
346 sizeof(chipinfo
.label
));
347 chipinfo
.label
[sizeof(chipinfo
.label
)-1] = '\0';
348 chipinfo
.lines
= gdev
->ngpio
;
349 if (copy_to_user(ip
, &chipinfo
, sizeof(chipinfo
)))
357 * gpio_chrdev_open() - open the chardev for ioctl operations
358 * @inode: inode for this chardev
359 * @filp: file struct for storing private data
360 * Returns 0 on success
362 static int gpio_chrdev_open(struct inode
*inode
, struct file
*filp
)
364 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
365 struct gpio_device
, chrdev
);
367 /* Fail on open if the backing gpiochip is gone */
368 if (!gdev
|| !gdev
->chip
)
370 get_device(&gdev
->dev
);
371 filp
->private_data
= gdev
;
376 * gpio_chrdev_release() - close chardev after ioctl operations
377 * @inode: inode for this chardev
378 * @filp: file struct for storing private data
379 * Returns 0 on success
381 static int gpio_chrdev_release(struct inode
*inode
, struct file
*filp
)
383 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
384 struct gpio_device
, chrdev
);
388 put_device(&gdev
->dev
);
393 static const struct file_operations gpio_fileops
= {
394 .release
= gpio_chrdev_release
,
395 .open
= gpio_chrdev_open
,
396 .owner
= THIS_MODULE
,
397 .llseek
= noop_llseek
,
398 .unlocked_ioctl
= gpio_ioctl
,
399 .compat_ioctl
= gpio_ioctl
,
402 static void gpiodevice_release(struct device
*dev
)
404 struct gpio_device
*gdev
= dev_get_drvdata(dev
);
406 cdev_del(&gdev
->chrdev
);
407 list_del(&gdev
->list
);
408 ida_simple_remove(&gpio_ida
, gdev
->id
);
413 * gpiochip_add_data() - register a gpio_chip
414 * @chip: the chip to register, with chip->base initialized
415 * Context: potentially before irqs will work
417 * Returns a negative errno if the chip can't be registered, such as
418 * because the chip->base is invalid or already associated with a
419 * different chip. Otherwise it returns zero as a success code.
421 * When gpiochip_add_data() is called very early during boot, so that GPIOs
422 * can be freely used, the chip->parent device must be registered before
423 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
424 * for GPIOs will fail rudely.
426 * If chip->base is negative, this requests dynamic assignment of
427 * a range of valid GPIOs.
429 int gpiochip_add_data(struct gpio_chip
*chip
, void *data
)
434 int base
= chip
->base
;
435 struct gpio_device
*gdev
;
438 * First: allocate and populate the internal stat container, and
439 * set up the struct device.
441 gdev
= kzalloc(sizeof(*gdev
), GFP_KERNEL
);
444 gdev
->dev
.bus
= &gpio_bus_type
;
446 chip
->gpiodev
= gdev
;
448 gdev
->dev
.parent
= chip
->parent
;
449 gdev
->dev
.of_node
= chip
->parent
->of_node
;
451 #ifdef CONFIG_OF_GPIO
452 /* If the gpiochip has an assigned OF node this takes precedence */
454 gdev
->dev
.of_node
= chip
->of_node
;
457 gdev
->id
= ida_simple_get(&gpio_ida
, 0, 0, GFP_KERNEL
);
462 dev_set_name(&gdev
->dev
, "gpiochip%d", gdev
->id
);
463 device_initialize(&gdev
->dev
);
464 dev_set_drvdata(&gdev
->dev
, gdev
);
465 if (chip
->parent
&& chip
->parent
->driver
)
466 gdev
->owner
= chip
->parent
->driver
->owner
;
467 else if (chip
->owner
)
468 /* TODO: remove chip->owner */
469 gdev
->owner
= chip
->owner
;
471 gdev
->owner
= THIS_MODULE
;
473 gdev
->descs
= devm_kcalloc(&gdev
->dev
, chip
->ngpio
,
474 sizeof(gdev
->descs
[0]), GFP_KERNEL
);
480 if (chip
->ngpio
== 0) {
481 chip_err(chip
, "tried to insert a GPIO chip with zero lines\n");
487 gdev
->label
= devm_kstrdup(&gdev
->dev
, chip
->label
, GFP_KERNEL
);
489 gdev
->label
= devm_kstrdup(&gdev
->dev
, "unknown", GFP_KERNEL
);
495 gdev
->ngpio
= chip
->ngpio
;
498 spin_lock_irqsave(&gpio_lock
, flags
);
501 * TODO: this allocates a Linux GPIO number base in the global
502 * GPIO numberspace for this chip. In the long run we want to
503 * get *rid* of this numberspace and use only descriptors, but
504 * it may be a pipe dream. It will not happen before we get rid
505 * of the sysfs interface anyways.
508 base
= gpiochip_find_base(chip
->ngpio
);
511 spin_unlock_irqrestore(&gpio_lock
, flags
);
515 * TODO: it should not be necessary to reflect the assigned
516 * base outside of the GPIO subsystem. Go over drivers and
517 * see if anyone makes use of this, else drop this and assign
524 status
= gpiodev_add_to_list(gdev
);
526 spin_unlock_irqrestore(&gpio_lock
, flags
);
530 for (i
= 0; i
< chip
->ngpio
; i
++) {
531 struct gpio_desc
*desc
= &gdev
->descs
[i
];
535 /* REVISIT: most hardware initializes GPIOs as inputs (often
536 * with pullups enabled) so power usage is minimized. Linux
537 * code should set the gpio direction first thing; but until
538 * it does, and in case chip->get_direction is not set, we may
539 * expose the wrong direction in sysfs.
541 desc
->flags
= !chip
->direction_input
? (1 << FLAG_IS_OUT
) : 0;
544 spin_unlock_irqrestore(&gpio_lock
, flags
);
546 #ifdef CONFIG_PINCTRL
547 INIT_LIST_HEAD(&gdev
->pin_ranges
);
550 status
= gpiochip_set_desc_names(chip
);
552 goto err_remove_from_list
;
554 status
= of_gpiochip_add(chip
);
556 goto err_remove_chip
;
558 acpi_gpiochip_add(chip
);
561 * By first adding the chardev, and then adding the device,
562 * we get a device node entry in sysfs under
563 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
564 * coldplug of device nodes and other udev business.
566 cdev_init(&gdev
->chrdev
, &gpio_fileops
);
567 gdev
->chrdev
.owner
= THIS_MODULE
;
568 gdev
->chrdev
.kobj
.parent
= &gdev
->dev
.kobj
;
569 gdev
->dev
.devt
= MKDEV(MAJOR(gpio_devt
), gdev
->id
);
570 status
= cdev_add(&gdev
->chrdev
, gdev
->dev
.devt
, 1);
572 chip_warn(chip
, "failed to add char device %d:%d\n",
573 MAJOR(gpio_devt
), gdev
->id
);
575 chip_dbg(chip
, "added GPIO chardev (%d:%d)\n",
576 MAJOR(gpio_devt
), gdev
->id
);
577 status
= device_add(&gdev
->dev
);
579 goto err_remove_chardev
;
581 status
= gpiochip_sysfs_register(gdev
);
583 goto err_remove_device
;
585 /* From this point, the .release() function cleans up gpio_device */
586 gdev
->dev
.release
= gpiodevice_release
;
587 get_device(&gdev
->dev
);
588 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
589 __func__
, gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
590 dev_name(&gdev
->dev
), chip
->label
? : "generic");
595 device_del(&gdev
->dev
);
597 cdev_del(&gdev
->chrdev
);
599 acpi_gpiochip_remove(chip
);
600 gpiochip_free_hogs(chip
);
601 of_gpiochip_remove(chip
);
602 err_remove_from_list
:
603 spin_lock_irqsave(&gpio_lock
, flags
);
604 list_del(&gdev
->list
);
605 spin_unlock_irqrestore(&gpio_lock
, flags
);
607 ida_simple_remove(&gpio_ida
, gdev
->id
);
608 /* failures here can mean systems won't boot... */
609 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__
,
610 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
611 chip
->label
? : "generic");
615 EXPORT_SYMBOL_GPL(gpiochip_add_data
);
618 * gpiochip_get_data() - get per-subdriver data for the chip
620 void *gpiochip_get_data(struct gpio_chip
*chip
)
622 return chip
->gpiodev
->data
;
624 EXPORT_SYMBOL_GPL(gpiochip_get_data
);
627 * gpiochip_remove() - unregister a gpio_chip
628 * @chip: the chip to unregister
630 * A gpio_chip with any GPIOs still requested may not be removed.
632 void gpiochip_remove(struct gpio_chip
*chip
)
634 struct gpio_device
*gdev
= chip
->gpiodev
;
635 struct gpio_desc
*desc
;
638 bool requested
= false;
640 /* Numb the device, cancelling all outstanding operations */
643 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
644 gpiochip_sysfs_unregister(gdev
);
645 gpiochip_irqchip_remove(chip
);
646 acpi_gpiochip_remove(chip
);
647 gpiochip_remove_pin_ranges(chip
);
648 gpiochip_free_hogs(chip
);
649 of_gpiochip_remove(chip
);
651 * We accept no more calls into the driver from this point, so
652 * NULL the driver data pointer
656 spin_lock_irqsave(&gpio_lock
, flags
);
657 for (i
= 0; i
< gdev
->ngpio
; i
++) {
658 desc
= &gdev
->descs
[i
];
659 if (test_bit(FLAG_REQUESTED
, &desc
->flags
))
662 spin_unlock_irqrestore(&gpio_lock
, flags
);
666 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
669 * The gpiochip side puts its use of the device to rest here:
670 * if there are no userspace clients, the chardev and device will
671 * be removed, else it will be dangling until the last user is
674 put_device(&gdev
->dev
);
676 EXPORT_SYMBOL_GPL(gpiochip_remove
);
679 * gpiochip_find() - iterator for locating a specific gpio_chip
680 * @data: data to pass to match function
681 * @callback: Callback function to check gpio_chip
683 * Similar to bus_find_device. It returns a reference to a gpio_chip as
684 * determined by a user supplied @match callback. The callback should return
685 * 0 if the device doesn't match and non-zero if it does. If the callback is
686 * non-zero, this function will return to the caller and not iterate over any
689 struct gpio_chip
*gpiochip_find(void *data
,
690 int (*match
)(struct gpio_chip
*chip
,
693 struct gpio_device
*gdev
;
694 struct gpio_chip
*chip
;
697 spin_lock_irqsave(&gpio_lock
, flags
);
698 list_for_each_entry(gdev
, &gpio_devices
, list
)
699 if (match(gdev
->chip
, data
))
703 if (&gdev
->list
== &gpio_devices
)
708 spin_unlock_irqrestore(&gpio_lock
, flags
);
712 EXPORT_SYMBOL_GPL(gpiochip_find
);
714 static int gpiochip_match_name(struct gpio_chip
*chip
, void *data
)
716 const char *name
= data
;
718 return !strcmp(chip
->label
, name
);
721 static struct gpio_chip
*find_chip_by_name(const char *name
)
723 return gpiochip_find((void *)name
, gpiochip_match_name
);
726 #ifdef CONFIG_GPIOLIB_IRQCHIP
729 * The following is irqchip helper code for gpiochips.
733 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
734 * @gpiochip: the gpiochip to set the irqchip chain to
735 * @irqchip: the irqchip to chain to the gpiochip
736 * @parent_irq: the irq number corresponding to the parent IRQ for this
738 * @parent_handler: the parent interrupt handler for the accumulated IRQ
739 * coming out of the gpiochip. If the interrupt is nested rather than
740 * cascaded, pass NULL in this handler argument
742 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
743 struct irq_chip
*irqchip
,
745 irq_flow_handler_t parent_handler
)
749 if (!gpiochip
->irqdomain
) {
750 chip_err(gpiochip
, "called %s before setting up irqchip\n",
755 if (parent_handler
) {
756 if (gpiochip
->can_sleep
) {
758 "you cannot have chained interrupts on a "
759 "chip that may sleep\n");
763 * The parent irqchip is already using the chip_data for this
764 * irqchip, so our callbacks simply use the handler_data.
766 irq_set_chained_handler_and_data(parent_irq
, parent_handler
,
769 gpiochip
->irq_parent
= parent_irq
;
772 /* Set the parent IRQ for all affected IRQs */
773 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
774 irq_set_parent(irq_find_mapping(gpiochip
->irqdomain
, offset
),
777 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip
);
780 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
781 * @d: the irqdomain used by this irqchip
782 * @irq: the global irq number used by this GPIO irqchip irq
783 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
785 * This function will set up the mapping for a certain IRQ line on a
786 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
787 * stored inside the gpiochip.
789 static int gpiochip_irq_map(struct irq_domain
*d
, unsigned int irq
,
790 irq_hw_number_t hwirq
)
792 struct gpio_chip
*chip
= d
->host_data
;
794 irq_set_chip_data(irq
, chip
);
796 * This lock class tells lockdep that GPIO irqs are in a different
797 * category than their parents, so it won't report false recursion.
799 irq_set_lockdep_class(irq
, chip
->lock_key
);
800 irq_set_chip_and_handler(irq
, chip
->irqchip
, chip
->irq_handler
);
801 /* Chips that can sleep need nested thread handlers */
802 if (chip
->can_sleep
&& !chip
->irq_not_threaded
)
803 irq_set_nested_thread(irq
, 1);
804 irq_set_noprobe(irq
);
807 * No set-up of the hardware will happen if IRQ_TYPE_NONE
808 * is passed as default type.
810 if (chip
->irq_default_type
!= IRQ_TYPE_NONE
)
811 irq_set_irq_type(irq
, chip
->irq_default_type
);
816 static void gpiochip_irq_unmap(struct irq_domain
*d
, unsigned int irq
)
818 struct gpio_chip
*chip
= d
->host_data
;
821 irq_set_nested_thread(irq
, 0);
822 irq_set_chip_and_handler(irq
, NULL
, NULL
);
823 irq_set_chip_data(irq
, NULL
);
826 static const struct irq_domain_ops gpiochip_domain_ops
= {
827 .map
= gpiochip_irq_map
,
828 .unmap
= gpiochip_irq_unmap
,
829 /* Virtually all GPIO irqchips are twocell:ed */
830 .xlate
= irq_domain_xlate_twocell
,
833 static int gpiochip_irq_reqres(struct irq_data
*d
)
835 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
837 if (!try_module_get(chip
->gpiodev
->owner
))
840 if (gpiochip_lock_as_irq(chip
, d
->hwirq
)) {
842 "unable to lock HW IRQ %lu for IRQ\n",
844 module_put(chip
->gpiodev
->owner
);
850 static void gpiochip_irq_relres(struct irq_data
*d
)
852 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
854 gpiochip_unlock_as_irq(chip
, d
->hwirq
);
855 module_put(chip
->gpiodev
->owner
);
858 static int gpiochip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
860 return irq_find_mapping(chip
->irqdomain
, offset
);
864 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
865 * @gpiochip: the gpiochip to remove the irqchip from
867 * This is called only from gpiochip_remove()
869 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
)
873 acpi_gpiochip_free_interrupts(gpiochip
);
875 if (gpiochip
->irq_parent
) {
876 irq_set_chained_handler(gpiochip
->irq_parent
, NULL
);
877 irq_set_handler_data(gpiochip
->irq_parent
, NULL
);
880 /* Remove all IRQ mappings and delete the domain */
881 if (gpiochip
->irqdomain
) {
882 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
884 irq_find_mapping(gpiochip
->irqdomain
, offset
));
885 irq_domain_remove(gpiochip
->irqdomain
);
888 if (gpiochip
->irqchip
) {
889 gpiochip
->irqchip
->irq_request_resources
= NULL
;
890 gpiochip
->irqchip
->irq_release_resources
= NULL
;
891 gpiochip
->irqchip
= NULL
;
896 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
897 * @gpiochip: the gpiochip to add the irqchip to
898 * @irqchip: the irqchip to add to the gpiochip
899 * @first_irq: if not dynamically assigned, the base (first) IRQ to
900 * allocate gpiochip irqs from
901 * @handler: the irq handler to use (often a predefined irq core function)
902 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
903 * to have the core avoid setting up any default type in the hardware.
904 * @lock_key: lockdep class
906 * This function closely associates a certain irqchip with a certain
907 * gpiochip, providing an irq domain to translate the local IRQs to
908 * global irqs in the gpiolib core, and making sure that the gpiochip
909 * is passed as chip data to all related functions. Driver callbacks
910 * need to use gpiochip_get_data() to get their local state containers back
911 * from the gpiochip passed as chip data. An irqdomain will be stored
912 * in the gpiochip that shall be used by the driver to handle IRQ number
913 * translation. The gpiochip will need to be initialized and registered
914 * before calling this function.
916 * This function will handle two cell:ed simple IRQs and assumes all
917 * the pins on the gpiochip can generate a unique IRQ. Everything else
918 * need to be open coded.
920 int _gpiochip_irqchip_add(struct gpio_chip
*gpiochip
,
921 struct irq_chip
*irqchip
,
922 unsigned int first_irq
,
923 irq_flow_handler_t handler
,
925 struct lock_class_key
*lock_key
)
927 struct device_node
*of_node
;
929 unsigned irq_base
= 0;
931 if (!gpiochip
|| !irqchip
)
934 if (!gpiochip
->parent
) {
935 pr_err("missing gpiochip .dev parent pointer\n");
938 of_node
= gpiochip
->parent
->of_node
;
939 #ifdef CONFIG_OF_GPIO
941 * If the gpiochip has an assigned OF node this takes precedence
942 * FIXME: get rid of this and use gpiochip->parent->of_node
945 if (gpiochip
->of_node
)
946 of_node
= gpiochip
->of_node
;
948 gpiochip
->irqchip
= irqchip
;
949 gpiochip
->irq_handler
= handler
;
950 gpiochip
->irq_default_type
= type
;
951 gpiochip
->to_irq
= gpiochip_to_irq
;
952 gpiochip
->lock_key
= lock_key
;
953 gpiochip
->irqdomain
= irq_domain_add_simple(of_node
,
954 gpiochip
->ngpio
, first_irq
,
955 &gpiochip_domain_ops
, gpiochip
);
956 if (!gpiochip
->irqdomain
) {
957 gpiochip
->irqchip
= NULL
;
962 * It is possible for a driver to override this, but only if the
963 * alternative functions are both implemented.
965 if (!irqchip
->irq_request_resources
&&
966 !irqchip
->irq_release_resources
) {
967 irqchip
->irq_request_resources
= gpiochip_irq_reqres
;
968 irqchip
->irq_release_resources
= gpiochip_irq_relres
;
972 * Prepare the mapping since the irqchip shall be orthogonal to
973 * any gpiochip calls. If the first_irq was zero, this is
974 * necessary to allocate descriptors for all IRQs.
976 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
977 irq_base
= irq_create_mapping(gpiochip
->irqdomain
, offset
);
980 * Store the base into the gpiochip to be used when
981 * unmapping the irqs.
983 gpiochip
->irq_base
= irq_base
;
986 acpi_gpiochip_request_interrupts(gpiochip
);
990 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add
);
992 #else /* CONFIG_GPIOLIB_IRQCHIP */
994 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
) {}
996 #endif /* CONFIG_GPIOLIB_IRQCHIP */
999 * gpiochip_generic_request() - request the gpio function for a pin
1000 * @chip: the gpiochip owning the GPIO
1001 * @offset: the offset of the GPIO to request for GPIO function
1003 int gpiochip_generic_request(struct gpio_chip
*chip
, unsigned offset
)
1005 return pinctrl_request_gpio(chip
->gpiodev
->base
+ offset
);
1007 EXPORT_SYMBOL_GPL(gpiochip_generic_request
);
1010 * gpiochip_generic_free() - free the gpio function from a pin
1011 * @chip: the gpiochip to request the gpio function for
1012 * @offset: the offset of the GPIO to free from GPIO function
1014 void gpiochip_generic_free(struct gpio_chip
*chip
, unsigned offset
)
1016 pinctrl_free_gpio(chip
->gpiodev
->base
+ offset
);
1018 EXPORT_SYMBOL_GPL(gpiochip_generic_free
);
1020 #ifdef CONFIG_PINCTRL
1023 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1024 * @chip: the gpiochip to add the range for
1025 * @pctldev: the pin controller to map to
1026 * @gpio_offset: the start offset in the current gpio_chip number space
1027 * @pin_group: name of the pin group inside the pin controller
1029 int gpiochip_add_pingroup_range(struct gpio_chip
*chip
,
1030 struct pinctrl_dev
*pctldev
,
1031 unsigned int gpio_offset
, const char *pin_group
)
1033 struct gpio_pin_range
*pin_range
;
1034 struct gpio_device
*gdev
= chip
->gpiodev
;
1037 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1039 chip_err(chip
, "failed to allocate pin ranges\n");
1043 /* Use local offset as range ID */
1044 pin_range
->range
.id
= gpio_offset
;
1045 pin_range
->range
.gc
= chip
;
1046 pin_range
->range
.name
= chip
->label
;
1047 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1048 pin_range
->pctldev
= pctldev
;
1050 ret
= pinctrl_get_group_pins(pctldev
, pin_group
,
1051 &pin_range
->range
.pins
,
1052 &pin_range
->range
.npins
);
1058 pinctrl_add_gpio_range(pctldev
, &pin_range
->range
);
1060 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1061 gpio_offset
, gpio_offset
+ pin_range
->range
.npins
- 1,
1062 pinctrl_dev_get_devname(pctldev
), pin_group
);
1064 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1068 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range
);
1071 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1072 * @chip: the gpiochip to add the range for
1073 * @pinctrl_name: the dev_name() of the pin controller to map to
1074 * @gpio_offset: the start offset in the current gpio_chip number space
1075 * @pin_offset: the start offset in the pin controller number space
1076 * @npins: the number of pins from the offset of each pin space (GPIO and
1077 * pin controller) to accumulate in this range
1079 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
1080 unsigned int gpio_offset
, unsigned int pin_offset
,
1083 struct gpio_pin_range
*pin_range
;
1084 struct gpio_device
*gdev
= chip
->gpiodev
;
1087 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1089 chip_err(chip
, "failed to allocate pin ranges\n");
1093 /* Use local offset as range ID */
1094 pin_range
->range
.id
= gpio_offset
;
1095 pin_range
->range
.gc
= chip
;
1096 pin_range
->range
.name
= chip
->label
;
1097 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1098 pin_range
->range
.pin_base
= pin_offset
;
1099 pin_range
->range
.npins
= npins
;
1100 pin_range
->pctldev
= pinctrl_find_and_add_gpio_range(pinctl_name
,
1102 if (IS_ERR(pin_range
->pctldev
)) {
1103 ret
= PTR_ERR(pin_range
->pctldev
);
1104 chip_err(chip
, "could not create pin range\n");
1108 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1109 gpio_offset
, gpio_offset
+ npins
- 1,
1111 pin_offset
, pin_offset
+ npins
- 1);
1113 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1117 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range
);
1120 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1121 * @chip: the chip to remove all the mappings for
1123 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
1125 struct gpio_pin_range
*pin_range
, *tmp
;
1126 struct gpio_device
*gdev
= chip
->gpiodev
;
1128 list_for_each_entry_safe(pin_range
, tmp
, &gdev
->pin_ranges
, node
) {
1129 list_del(&pin_range
->node
);
1130 pinctrl_remove_gpio_range(pin_range
->pctldev
,
1135 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges
);
1137 #endif /* CONFIG_PINCTRL */
1139 /* These "optional" allocation calls help prevent drivers from stomping
1140 * on each other, and help provide better diagnostics in debugfs.
1141 * They're called even less than the "set direction" calls.
1143 static int __gpiod_request(struct gpio_desc
*desc
, const char *label
)
1145 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1147 unsigned long flags
;
1149 spin_lock_irqsave(&gpio_lock
, flags
);
1151 /* NOTE: gpio_request() can be called in early boot,
1152 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1155 if (test_and_set_bit(FLAG_REQUESTED
, &desc
->flags
) == 0) {
1156 desc_set_label(desc
, label
? : "?");
1163 if (chip
->request
) {
1164 /* chip->request may sleep */
1165 spin_unlock_irqrestore(&gpio_lock
, flags
);
1166 status
= chip
->request(chip
, gpio_chip_hwgpio(desc
));
1167 spin_lock_irqsave(&gpio_lock
, flags
);
1170 desc_set_label(desc
, NULL
);
1171 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1175 if (chip
->get_direction
) {
1176 /* chip->get_direction may sleep */
1177 spin_unlock_irqrestore(&gpio_lock
, flags
);
1178 gpiod_get_direction(desc
);
1179 spin_lock_irqsave(&gpio_lock
, flags
);
1183 /* Clear flags that might have been set by the caller before
1184 * requesting the GPIO.
1186 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1187 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1188 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1190 spin_unlock_irqrestore(&gpio_lock
, flags
);
1195 * This descriptor validation needs to be inserted verbatim into each
1196 * function taking a descriptor, so we need to use a preprocessor
1197 * macro to avoid endless duplication.
1199 #define VALIDATE_DESC(desc) do { \
1200 if (!desc || !desc->gdev) { \
1201 pr_warn("%s: invalid GPIO\n", __func__); \
1204 if ( !desc->gdev->chip ) { \
1205 dev_warn(&desc->gdev->dev, \
1206 "%s: backing chip is gone\n", __func__); \
1210 #define VALIDATE_DESC_VOID(desc) do { \
1211 if (!desc || !desc->gdev) { \
1212 pr_warn("%s: invalid GPIO\n", __func__); \
1215 if (!desc->gdev->chip) { \
1216 dev_warn(&desc->gdev->dev, \
1217 "%s: backing chip is gone\n", __func__); \
1222 int gpiod_request(struct gpio_desc
*desc
, const char *label
)
1224 int status
= -EPROBE_DEFER
;
1225 struct gpio_device
*gdev
;
1227 VALIDATE_DESC(desc
);
1230 if (try_module_get(gdev
->owner
)) {
1231 status
= __gpiod_request(desc
, label
);
1233 module_put(gdev
->owner
);
1235 get_device(&gdev
->dev
);
1239 gpiod_dbg(desc
, "%s: status %d\n", __func__
, status
);
1244 static bool __gpiod_free(struct gpio_desc
*desc
)
1247 unsigned long flags
;
1248 struct gpio_chip
*chip
;
1252 gpiod_unexport(desc
);
1254 spin_lock_irqsave(&gpio_lock
, flags
);
1256 chip
= desc
->gdev
->chip
;
1257 if (chip
&& test_bit(FLAG_REQUESTED
, &desc
->flags
)) {
1259 spin_unlock_irqrestore(&gpio_lock
, flags
);
1260 might_sleep_if(chip
->can_sleep
);
1261 chip
->free(chip
, gpio_chip_hwgpio(desc
));
1262 spin_lock_irqsave(&gpio_lock
, flags
);
1264 desc_set_label(desc
, NULL
);
1265 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1266 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1267 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1268 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1269 clear_bit(FLAG_IS_HOGGED
, &desc
->flags
);
1273 spin_unlock_irqrestore(&gpio_lock
, flags
);
1277 void gpiod_free(struct gpio_desc
*desc
)
1279 if (desc
&& desc
->gdev
&& __gpiod_free(desc
)) {
1280 module_put(desc
->gdev
->owner
);
1281 put_device(&desc
->gdev
->dev
);
1283 WARN_ON(extra_checks
);
1288 * gpiochip_is_requested - return string iff signal was requested
1289 * @chip: controller managing the signal
1290 * @offset: of signal within controller's 0..(ngpio - 1) range
1292 * Returns NULL if the GPIO is not currently requested, else a string.
1293 * The string returned is the label passed to gpio_request(); if none has been
1294 * passed it is a meaningless, non-NULL constant.
1296 * This function is for use by GPIO controller drivers. The label can
1297 * help with diagnostics, and knowing that the signal is used as a GPIO
1298 * can help avoid accidentally multiplexing it to another controller.
1300 const char *gpiochip_is_requested(struct gpio_chip
*chip
, unsigned offset
)
1302 struct gpio_desc
*desc
;
1304 if (offset
>= chip
->ngpio
)
1307 desc
= &chip
->gpiodev
->descs
[offset
];
1309 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) == 0)
1313 EXPORT_SYMBOL_GPL(gpiochip_is_requested
);
1316 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1317 * @desc: GPIO descriptor to request
1318 * @label: label for the GPIO
1320 * Function allows GPIO chip drivers to request and use their own GPIO
1321 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1322 * function will not increase reference count of the GPIO chip module. This
1323 * allows the GPIO chip module to be unloaded as needed (we assume that the
1324 * GPIO chip driver handles freeing the GPIOs it has requested).
1326 struct gpio_desc
*gpiochip_request_own_desc(struct gpio_chip
*chip
, u16 hwnum
,
1329 struct gpio_desc
*desc
= gpiochip_get_desc(chip
, hwnum
);
1333 chip_err(chip
, "failed to get GPIO descriptor\n");
1337 err
= __gpiod_request(desc
, label
);
1339 return ERR_PTR(err
);
1343 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc
);
1346 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1347 * @desc: GPIO descriptor to free
1349 * Function frees the given GPIO requested previously with
1350 * gpiochip_request_own_desc().
1352 void gpiochip_free_own_desc(struct gpio_desc
*desc
)
1357 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc
);
1360 * Drivers MUST set GPIO direction before making get/set calls. In
1361 * some cases this is done in early boot, before IRQs are enabled.
1363 * As a rule these aren't called more than once (except for drivers
1364 * using the open-drain emulation idiom) so these are natural places
1365 * to accumulate extra debugging checks. Note that we can't (yet)
1366 * rely on gpio_request() having been called beforehand.
1370 * gpiod_direction_input - set the GPIO direction to input
1371 * @desc: GPIO to set to input
1373 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1374 * be called safely on it.
1376 * Return 0 in case of success, else an error code.
1378 int gpiod_direction_input(struct gpio_desc
*desc
)
1380 struct gpio_chip
*chip
;
1381 int status
= -EINVAL
;
1383 VALIDATE_DESC(desc
);
1384 chip
= desc
->gdev
->chip
;
1386 if (!chip
->get
|| !chip
->direction_input
) {
1388 "%s: missing get() or direction_input() operations\n",
1393 status
= chip
->direction_input(chip
, gpio_chip_hwgpio(desc
));
1395 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1397 trace_gpio_direction(desc_to_gpio(desc
), 1, status
);
1401 EXPORT_SYMBOL_GPL(gpiod_direction_input
);
1403 static int _gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1405 struct gpio_chip
*chip
;
1406 int status
= -EINVAL
;
1408 /* GPIOs used for IRQs shall not be set as output */
1409 if (test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
)) {
1411 "%s: tried to set a GPIO tied to an IRQ as output\n",
1416 /* Open drain pin should not be driven to 1 */
1417 if (value
&& test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
1418 return gpiod_direction_input(desc
);
1420 /* Open source pin should not be driven to 0 */
1421 if (!value
&& test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
1422 return gpiod_direction_input(desc
);
1424 chip
= desc
->gdev
->chip
;
1425 if (!chip
->set
|| !chip
->direction_output
) {
1427 "%s: missing set() or direction_output() operations\n",
1432 status
= chip
->direction_output(chip
, gpio_chip_hwgpio(desc
), value
);
1434 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1435 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1436 trace_gpio_direction(desc_to_gpio(desc
), 0, status
);
1441 * gpiod_direction_output_raw - set the GPIO direction to output
1442 * @desc: GPIO to set to output
1443 * @value: initial output value of the GPIO
1445 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1446 * be called safely on it. The initial value of the output must be specified
1447 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1449 * Return 0 in case of success, else an error code.
1451 int gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1453 VALIDATE_DESC(desc
);
1454 return _gpiod_direction_output_raw(desc
, value
);
1456 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw
);
1459 * gpiod_direction_output - set the GPIO direction to output
1460 * @desc: GPIO to set to output
1461 * @value: initial output value of the GPIO
1463 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1464 * be called safely on it. The initial value of the output must be specified
1465 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1468 * Return 0 in case of success, else an error code.
1470 int gpiod_direction_output(struct gpio_desc
*desc
, int value
)
1472 VALIDATE_DESC(desc
);
1473 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1475 return _gpiod_direction_output_raw(desc
, value
);
1477 EXPORT_SYMBOL_GPL(gpiod_direction_output
);
1480 * gpiod_set_debounce - sets @debounce time for a @gpio
1481 * @gpio: the gpio to set debounce time
1482 * @debounce: debounce time is microseconds
1484 * returns -ENOTSUPP if the controller does not support setting
1487 int gpiod_set_debounce(struct gpio_desc
*desc
, unsigned debounce
)
1489 struct gpio_chip
*chip
;
1491 VALIDATE_DESC(desc
);
1492 chip
= desc
->gdev
->chip
;
1493 if (!chip
->set
|| !chip
->set_debounce
) {
1495 "%s: missing set() or set_debounce() operations\n",
1500 return chip
->set_debounce(chip
, gpio_chip_hwgpio(desc
), debounce
);
1502 EXPORT_SYMBOL_GPL(gpiod_set_debounce
);
1505 * gpiod_is_active_low - test whether a GPIO is active-low or not
1506 * @desc: the gpio descriptor to test
1508 * Returns 1 if the GPIO is active-low, 0 otherwise.
1510 int gpiod_is_active_low(const struct gpio_desc
*desc
)
1512 VALIDATE_DESC(desc
);
1513 return test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1515 EXPORT_SYMBOL_GPL(gpiod_is_active_low
);
1517 /* I/O calls are only valid after configuration completed; the relevant
1518 * "is this a valid GPIO" error checks should already have been done.
1520 * "Get" operations are often inlinable as reading a pin value register,
1521 * and masking the relevant bit in that register.
1523 * When "set" operations are inlinable, they involve writing that mask to
1524 * one register to set a low value, or a different register to set it high.
1525 * Otherwise locking is needed, so there may be little value to inlining.
1527 *------------------------------------------------------------------------
1529 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1530 * have requested the GPIO. That can include implicit requesting by
1531 * a direction setting call. Marking a gpio as requested locks its chip
1532 * in memory, guaranteeing that these table lookups need no more locking
1533 * and that gpiochip_remove() will fail.
1535 * REVISIT when debugging, consider adding some instrumentation to ensure
1536 * that the GPIO was actually requested.
1539 static int _gpiod_get_raw_value(const struct gpio_desc
*desc
)
1541 struct gpio_chip
*chip
;
1545 chip
= desc
->gdev
->chip
;
1546 offset
= gpio_chip_hwgpio(desc
);
1547 value
= chip
->get
? chip
->get(chip
, offset
) : -EIO
;
1548 value
= value
< 0 ? value
: !!value
;
1549 trace_gpio_value(desc_to_gpio(desc
), 1, value
);
1554 * gpiod_get_raw_value() - return a gpio's raw value
1555 * @desc: gpio whose value will be returned
1557 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1558 * its ACTIVE_LOW status, or negative errno on failure.
1560 * This function should be called from contexts where we cannot sleep, and will
1561 * complain if the GPIO chip functions potentially sleep.
1563 int gpiod_get_raw_value(const struct gpio_desc
*desc
)
1565 VALIDATE_DESC(desc
);
1566 /* Should be using gpio_get_value_cansleep() */
1567 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1568 return _gpiod_get_raw_value(desc
);
1570 EXPORT_SYMBOL_GPL(gpiod_get_raw_value
);
1573 * gpiod_get_value() - return a gpio's value
1574 * @desc: gpio whose value will be returned
1576 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1577 * account, or negative errno on failure.
1579 * This function should be called from contexts where we cannot sleep, and will
1580 * complain if the GPIO chip functions potentially sleep.
1582 int gpiod_get_value(const struct gpio_desc
*desc
)
1586 VALIDATE_DESC(desc
);
1587 /* Should be using gpio_get_value_cansleep() */
1588 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1590 value
= _gpiod_get_raw_value(desc
);
1594 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1599 EXPORT_SYMBOL_GPL(gpiod_get_value
);
1602 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1603 * @desc: gpio descriptor whose state need to be set.
1604 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1606 static void _gpio_set_open_drain_value(struct gpio_desc
*desc
, bool value
)
1609 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1610 int offset
= gpio_chip_hwgpio(desc
);
1613 err
= chip
->direction_input(chip
, offset
);
1615 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1617 err
= chip
->direction_output(chip
, offset
, 0);
1619 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1621 trace_gpio_direction(desc_to_gpio(desc
), value
, err
);
1624 "%s: Error in set_value for open drain err %d\n",
1629 * _gpio_set_open_source_value() - Set the open source gpio's value.
1630 * @desc: gpio descriptor whose state need to be set.
1631 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1633 static void _gpio_set_open_source_value(struct gpio_desc
*desc
, bool value
)
1636 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1637 int offset
= gpio_chip_hwgpio(desc
);
1640 err
= chip
->direction_output(chip
, offset
, 1);
1642 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1644 err
= chip
->direction_input(chip
, offset
);
1646 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1648 trace_gpio_direction(desc_to_gpio(desc
), !value
, err
);
1651 "%s: Error in set_value for open source err %d\n",
1655 static void _gpiod_set_raw_value(struct gpio_desc
*desc
, bool value
)
1657 struct gpio_chip
*chip
;
1659 chip
= desc
->gdev
->chip
;
1660 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1661 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
1662 _gpio_set_open_drain_value(desc
, value
);
1663 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
1664 _gpio_set_open_source_value(desc
, value
);
1666 chip
->set(chip
, gpio_chip_hwgpio(desc
), value
);
1670 * set multiple outputs on the same chip;
1671 * use the chip's set_multiple function if available;
1672 * otherwise set the outputs sequentially;
1673 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1674 * defines which outputs are to be changed
1675 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1676 * defines the values the outputs specified by mask are to be set to
1678 static void gpio_chip_set_multiple(struct gpio_chip
*chip
,
1679 unsigned long *mask
, unsigned long *bits
)
1681 if (chip
->set_multiple
) {
1682 chip
->set_multiple(chip
, mask
, bits
);
1685 for (i
= 0; i
< chip
->ngpio
; i
++) {
1686 if (mask
[BIT_WORD(i
)] == 0) {
1687 /* no more set bits in this mask word;
1688 * skip ahead to the next word */
1689 i
= (BIT_WORD(i
) + 1) * BITS_PER_LONG
- 1;
1692 /* set outputs if the corresponding mask bit is set */
1693 if (__test_and_clear_bit(i
, mask
))
1694 chip
->set(chip
, i
, test_bit(i
, bits
));
1699 static void gpiod_set_array_value_priv(bool raw
, bool can_sleep
,
1700 unsigned int array_size
,
1701 struct gpio_desc
**desc_array
,
1706 while (i
< array_size
) {
1707 struct gpio_chip
*chip
= desc_array
[i
]->gdev
->chip
;
1708 unsigned long mask
[BITS_TO_LONGS(chip
->ngpio
)];
1709 unsigned long bits
[BITS_TO_LONGS(chip
->ngpio
)];
1713 WARN_ON(chip
->can_sleep
);
1715 memset(mask
, 0, sizeof(mask
));
1717 struct gpio_desc
*desc
= desc_array
[i
];
1718 int hwgpio
= gpio_chip_hwgpio(desc
);
1719 int value
= value_array
[i
];
1721 if (!raw
&& test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1723 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1725 * collect all normal outputs belonging to the same chip
1726 * open drain and open source outputs are set individually
1728 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
1729 _gpio_set_open_drain_value(desc
, value
);
1730 } else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
1731 _gpio_set_open_source_value(desc
, value
);
1733 __set_bit(hwgpio
, mask
);
1735 __set_bit(hwgpio
, bits
);
1737 __clear_bit(hwgpio
, bits
);
1741 } while ((i
< array_size
) &&
1742 (desc_array
[i
]->gdev
->chip
== chip
));
1743 /* push collected bits to outputs */
1745 gpio_chip_set_multiple(chip
, mask
, bits
);
1750 * gpiod_set_raw_value() - assign a gpio's raw value
1751 * @desc: gpio whose value will be assigned
1752 * @value: value to assign
1754 * Set the raw value of the GPIO, i.e. the value of its physical line without
1755 * regard for its ACTIVE_LOW status.
1757 * This function should be called from contexts where we cannot sleep, and will
1758 * complain if the GPIO chip functions potentially sleep.
1760 void gpiod_set_raw_value(struct gpio_desc
*desc
, int value
)
1762 VALIDATE_DESC_VOID(desc
);
1763 /* Should be using gpio_set_value_cansleep() */
1764 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1765 _gpiod_set_raw_value(desc
, value
);
1767 EXPORT_SYMBOL_GPL(gpiod_set_raw_value
);
1770 * gpiod_set_value() - assign a gpio's value
1771 * @desc: gpio whose value will be assigned
1772 * @value: value to assign
1774 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1777 * This function should be called from contexts where we cannot sleep, and will
1778 * complain if the GPIO chip functions potentially sleep.
1780 void gpiod_set_value(struct gpio_desc
*desc
, int value
)
1782 VALIDATE_DESC_VOID(desc
);
1783 /* Should be using gpio_set_value_cansleep() */
1784 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1785 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1787 _gpiod_set_raw_value(desc
, value
);
1789 EXPORT_SYMBOL_GPL(gpiod_set_value
);
1792 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1793 * @array_size: number of elements in the descriptor / value arrays
1794 * @desc_array: array of GPIO descriptors whose values will be assigned
1795 * @value_array: array of values to assign
1797 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1798 * without regard for their ACTIVE_LOW status.
1800 * This function should be called from contexts where we cannot sleep, and will
1801 * complain if the GPIO chip functions potentially sleep.
1803 void gpiod_set_raw_array_value(unsigned int array_size
,
1804 struct gpio_desc
**desc_array
, int *value_array
)
1808 gpiod_set_array_value_priv(true, false, array_size
, desc_array
,
1811 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value
);
1814 * gpiod_set_array_value() - assign values to an array of GPIOs
1815 * @array_size: number of elements in the descriptor / value arrays
1816 * @desc_array: array of GPIO descriptors whose values will be assigned
1817 * @value_array: array of values to assign
1819 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1822 * This function should be called from contexts where we cannot sleep, and will
1823 * complain if the GPIO chip functions potentially sleep.
1825 void gpiod_set_array_value(unsigned int array_size
,
1826 struct gpio_desc
**desc_array
, int *value_array
)
1830 gpiod_set_array_value_priv(false, false, array_size
, desc_array
,
1833 EXPORT_SYMBOL_GPL(gpiod_set_array_value
);
1836 * gpiod_cansleep() - report whether gpio value access may sleep
1837 * @desc: gpio to check
1840 int gpiod_cansleep(const struct gpio_desc
*desc
)
1842 VALIDATE_DESC(desc
);
1843 return desc
->gdev
->chip
->can_sleep
;
1845 EXPORT_SYMBOL_GPL(gpiod_cansleep
);
1848 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1849 * @desc: gpio whose IRQ will be returned (already requested)
1851 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1854 int gpiod_to_irq(const struct gpio_desc
*desc
)
1856 struct gpio_chip
*chip
;
1859 VALIDATE_DESC(desc
);
1860 chip
= desc
->gdev
->chip
;
1861 offset
= gpio_chip_hwgpio(desc
);
1862 return chip
->to_irq
? chip
->to_irq(chip
, offset
) : -ENXIO
;
1864 EXPORT_SYMBOL_GPL(gpiod_to_irq
);
1867 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1868 * @chip: the chip the GPIO to lock belongs to
1869 * @offset: the offset of the GPIO to lock as IRQ
1871 * This is used directly by GPIO drivers that want to lock down
1872 * a certain GPIO line to be used for IRQs.
1874 int gpiochip_lock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
1876 if (offset
>= chip
->ngpio
)
1879 if (test_bit(FLAG_IS_OUT
, &chip
->gpiodev
->descs
[offset
].flags
)) {
1881 "%s: tried to flag a GPIO set as output for IRQ\n",
1886 set_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
1889 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq
);
1892 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1893 * @chip: the chip the GPIO to lock belongs to
1894 * @offset: the offset of the GPIO to lock as IRQ
1896 * This is used directly by GPIO drivers that want to indicate
1897 * that a certain GPIO is no longer used exclusively for IRQ.
1899 void gpiochip_unlock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
1901 if (offset
>= chip
->ngpio
)
1904 clear_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
1906 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq
);
1908 bool gpiochip_line_is_irq(struct gpio_chip
*chip
, unsigned int offset
)
1910 if (offset
>= chip
->ngpio
)
1913 return test_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
1915 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq
);
1917 bool gpiochip_line_is_open_drain(struct gpio_chip
*chip
, unsigned int offset
)
1919 if (offset
>= chip
->ngpio
)
1922 return test_bit(FLAG_OPEN_DRAIN
, &chip
->gpiodev
->descs
[offset
].flags
);
1924 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain
);
1926 bool gpiochip_line_is_open_source(struct gpio_chip
*chip
, unsigned int offset
)
1928 if (offset
>= chip
->ngpio
)
1931 return test_bit(FLAG_OPEN_SOURCE
, &chip
->gpiodev
->descs
[offset
].flags
);
1933 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source
);
1936 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1937 * @desc: gpio whose value will be returned
1939 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1940 * its ACTIVE_LOW status, or negative errno on failure.
1942 * This function is to be called from contexts that can sleep.
1944 int gpiod_get_raw_value_cansleep(const struct gpio_desc
*desc
)
1946 might_sleep_if(extra_checks
);
1947 VALIDATE_DESC(desc
);
1948 return _gpiod_get_raw_value(desc
);
1950 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep
);
1953 * gpiod_get_value_cansleep() - return a gpio's value
1954 * @desc: gpio whose value will be returned
1956 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1957 * account, or negative errno on failure.
1959 * This function is to be called from contexts that can sleep.
1961 int gpiod_get_value_cansleep(const struct gpio_desc
*desc
)
1965 might_sleep_if(extra_checks
);
1966 VALIDATE_DESC(desc
);
1967 value
= _gpiod_get_raw_value(desc
);
1971 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1976 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep
);
1979 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
1980 * @desc: gpio whose value will be assigned
1981 * @value: value to assign
1983 * Set the raw value of the GPIO, i.e. the value of its physical line without
1984 * regard for its ACTIVE_LOW status.
1986 * This function is to be called from contexts that can sleep.
1988 void gpiod_set_raw_value_cansleep(struct gpio_desc
*desc
, int value
)
1990 might_sleep_if(extra_checks
);
1991 VALIDATE_DESC_VOID(desc
);
1992 _gpiod_set_raw_value(desc
, value
);
1994 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep
);
1997 * gpiod_set_value_cansleep() - assign a gpio's value
1998 * @desc: gpio whose value will be assigned
1999 * @value: value to assign
2001 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2004 * This function is to be called from contexts that can sleep.
2006 void gpiod_set_value_cansleep(struct gpio_desc
*desc
, int value
)
2008 might_sleep_if(extra_checks
);
2009 VALIDATE_DESC_VOID(desc
);
2010 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2012 _gpiod_set_raw_value(desc
, value
);
2014 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep
);
2017 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2018 * @array_size: number of elements in the descriptor / value arrays
2019 * @desc_array: array of GPIO descriptors whose values will be assigned
2020 * @value_array: array of values to assign
2022 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2023 * without regard for their ACTIVE_LOW status.
2025 * This function is to be called from contexts that can sleep.
2027 void gpiod_set_raw_array_value_cansleep(unsigned int array_size
,
2028 struct gpio_desc
**desc_array
,
2031 might_sleep_if(extra_checks
);
2034 gpiod_set_array_value_priv(true, true, array_size
, desc_array
,
2037 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep
);
2040 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2041 * @array_size: number of elements in the descriptor / value arrays
2042 * @desc_array: array of GPIO descriptors whose values will be assigned
2043 * @value_array: array of values to assign
2045 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2048 * This function is to be called from contexts that can sleep.
2050 void gpiod_set_array_value_cansleep(unsigned int array_size
,
2051 struct gpio_desc
**desc_array
,
2054 might_sleep_if(extra_checks
);
2057 gpiod_set_array_value_priv(false, true, array_size
, desc_array
,
2060 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep
);
2063 * gpiod_add_lookup_table() - register GPIO device consumers
2064 * @table: table of consumers to register
2066 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
)
2068 mutex_lock(&gpio_lookup_lock
);
2070 list_add_tail(&table
->list
, &gpio_lookup_list
);
2072 mutex_unlock(&gpio_lookup_lock
);
2076 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2077 * @table: table of consumers to unregister
2079 void gpiod_remove_lookup_table(struct gpiod_lookup_table
*table
)
2081 mutex_lock(&gpio_lookup_lock
);
2083 list_del(&table
->list
);
2085 mutex_unlock(&gpio_lookup_lock
);
2088 static struct gpio_desc
*of_find_gpio(struct device
*dev
, const char *con_id
,
2090 enum gpio_lookup_flags
*flags
)
2092 char prop_name
[32]; /* 32 is max size of property name */
2093 enum of_gpio_flags of_flags
;
2094 struct gpio_desc
*desc
;
2097 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2099 snprintf(prop_name
, sizeof(prop_name
), "%s-%s", con_id
,
2102 snprintf(prop_name
, sizeof(prop_name
), "%s",
2105 desc
= of_get_named_gpiod_flags(dev
->of_node
, prop_name
, idx
,
2107 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2114 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2115 *flags
|= GPIO_ACTIVE_LOW
;
2117 if (of_flags
& OF_GPIO_SINGLE_ENDED
) {
2118 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2119 *flags
|= GPIO_OPEN_DRAIN
;
2121 *flags
|= GPIO_OPEN_SOURCE
;
2127 static struct gpio_desc
*acpi_find_gpio(struct device
*dev
, const char *con_id
,
2129 enum gpio_lookup_flags
*flags
)
2131 struct acpi_device
*adev
= ACPI_COMPANION(dev
);
2132 struct acpi_gpio_info info
;
2133 struct gpio_desc
*desc
;
2137 /* Try first from _DSD */
2138 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2139 if (con_id
&& strcmp(con_id
, "gpios")) {
2140 snprintf(propname
, sizeof(propname
), "%s-%s",
2141 con_id
, gpio_suffixes
[i
]);
2143 snprintf(propname
, sizeof(propname
), "%s",
2147 desc
= acpi_get_gpiod_by_index(adev
, propname
, idx
, &info
);
2148 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2152 /* Then from plain _CRS GPIOs */
2154 if (!acpi_can_fallback_to_crs(adev
, con_id
))
2155 return ERR_PTR(-ENOENT
);
2157 desc
= acpi_get_gpiod_by_index(adev
, NULL
, idx
, &info
);
2162 if (info
.polarity
== GPIO_ACTIVE_LOW
)
2163 *flags
|= GPIO_ACTIVE_LOW
;
2168 static struct gpiod_lookup_table
*gpiod_find_lookup_table(struct device
*dev
)
2170 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
2171 struct gpiod_lookup_table
*table
;
2173 mutex_lock(&gpio_lookup_lock
);
2175 list_for_each_entry(table
, &gpio_lookup_list
, list
) {
2176 if (table
->dev_id
&& dev_id
) {
2178 * Valid strings on both ends, must be identical to have
2181 if (!strcmp(table
->dev_id
, dev_id
))
2185 * One of the pointers is NULL, so both must be to have
2188 if (dev_id
== table
->dev_id
)
2195 mutex_unlock(&gpio_lookup_lock
);
2199 static struct gpio_desc
*gpiod_find(struct device
*dev
, const char *con_id
,
2201 enum gpio_lookup_flags
*flags
)
2203 struct gpio_desc
*desc
= ERR_PTR(-ENOENT
);
2204 struct gpiod_lookup_table
*table
;
2205 struct gpiod_lookup
*p
;
2207 table
= gpiod_find_lookup_table(dev
);
2211 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2212 struct gpio_chip
*chip
;
2214 /* idx must always match exactly */
2218 /* If the lookup entry has a con_id, require exact match */
2219 if (p
->con_id
&& (!con_id
|| strcmp(p
->con_id
, con_id
)))
2222 chip
= find_chip_by_name(p
->chip_label
);
2225 dev_err(dev
, "cannot find GPIO chip %s\n",
2227 return ERR_PTR(-ENODEV
);
2230 if (chip
->ngpio
<= p
->chip_hwnum
) {
2232 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2233 idx
, chip
->ngpio
, chip
->label
);
2234 return ERR_PTR(-EINVAL
);
2237 desc
= gpiochip_get_desc(chip
, p
->chip_hwnum
);
2246 static int dt_gpio_count(struct device
*dev
, const char *con_id
)
2252 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2254 snprintf(propname
, sizeof(propname
), "%s-%s",
2255 con_id
, gpio_suffixes
[i
]);
2257 snprintf(propname
, sizeof(propname
), "%s",
2260 ret
= of_gpio_named_count(dev
->of_node
, propname
);
2267 static int platform_gpio_count(struct device
*dev
, const char *con_id
)
2269 struct gpiod_lookup_table
*table
;
2270 struct gpiod_lookup
*p
;
2271 unsigned int count
= 0;
2273 table
= gpiod_find_lookup_table(dev
);
2277 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2278 if ((con_id
&& p
->con_id
&& !strcmp(con_id
, p
->con_id
)) ||
2279 (!con_id
&& !p
->con_id
))
2289 * gpiod_count - return the number of GPIOs associated with a device / function
2290 * or -ENOENT if no GPIO has been assigned to the requested function
2291 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2292 * @con_id: function within the GPIO consumer
2294 int gpiod_count(struct device
*dev
, const char *con_id
)
2296 int count
= -ENOENT
;
2298 if (IS_ENABLED(CONFIG_OF
) && dev
&& dev
->of_node
)
2299 count
= dt_gpio_count(dev
, con_id
);
2300 else if (IS_ENABLED(CONFIG_ACPI
) && dev
&& ACPI_HANDLE(dev
))
2301 count
= acpi_gpio_count(dev
, con_id
);
2304 count
= platform_gpio_count(dev
, con_id
);
2308 EXPORT_SYMBOL_GPL(gpiod_count
);
2311 * gpiod_get - obtain a GPIO for a given GPIO function
2312 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2313 * @con_id: function within the GPIO consumer
2314 * @flags: optional GPIO initialization flags
2316 * Return the GPIO descriptor corresponding to the function con_id of device
2317 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2318 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2320 struct gpio_desc
*__must_check
gpiod_get(struct device
*dev
, const char *con_id
,
2321 enum gpiod_flags flags
)
2323 return gpiod_get_index(dev
, con_id
, 0, flags
);
2325 EXPORT_SYMBOL_GPL(gpiod_get
);
2328 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2329 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2330 * @con_id: function within the GPIO consumer
2331 * @flags: optional GPIO initialization flags
2333 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2334 * the requested function it will return NULL. This is convenient for drivers
2335 * that need to handle optional GPIOs.
2337 struct gpio_desc
*__must_check
gpiod_get_optional(struct device
*dev
,
2339 enum gpiod_flags flags
)
2341 return gpiod_get_index_optional(dev
, con_id
, 0, flags
);
2343 EXPORT_SYMBOL_GPL(gpiod_get_optional
);
2346 * gpiod_parse_flags - helper function to parse GPIO lookup flags
2347 * @desc: gpio to be setup
2348 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2351 * Set the GPIO descriptor flags based on the given GPIO lookup flags.
2353 static void gpiod_parse_flags(struct gpio_desc
*desc
, unsigned long lflags
)
2355 if (lflags
& GPIO_ACTIVE_LOW
)
2356 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2357 if (lflags
& GPIO_OPEN_DRAIN
)
2358 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2359 if (lflags
& GPIO_OPEN_SOURCE
)
2360 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2364 * gpiod_configure_flags - helper function to configure a given GPIO
2365 * @desc: gpio whose value will be assigned
2366 * @con_id: function within the GPIO consumer
2367 * @dflags: gpiod_flags - optional GPIO initialization flags
2369 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2370 * requested function and/or index, or another IS_ERR() code if an error
2371 * occurred while trying to acquire the GPIO.
2373 static int gpiod_configure_flags(struct gpio_desc
*desc
, const char *con_id
,
2374 enum gpiod_flags dflags
)
2378 /* No particular flag request, return here... */
2379 if (!(dflags
& GPIOD_FLAGS_BIT_DIR_SET
)) {
2380 pr_debug("no flags found for %s\n", con_id
);
2385 if (dflags
& GPIOD_FLAGS_BIT_DIR_OUT
)
2386 status
= gpiod_direction_output(desc
,
2387 dflags
& GPIOD_FLAGS_BIT_DIR_VAL
);
2389 status
= gpiod_direction_input(desc
);
2395 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2396 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2397 * @con_id: function within the GPIO consumer
2398 * @idx: index of the GPIO to obtain in the consumer
2399 * @flags: optional GPIO initialization flags
2401 * This variant of gpiod_get() allows to access GPIOs other than the first
2402 * defined one for functions that define several GPIOs.
2404 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2405 * requested function and/or index, or another IS_ERR() code if an error
2406 * occurred while trying to acquire the GPIO.
2408 struct gpio_desc
*__must_check
gpiod_get_index(struct device
*dev
,
2411 enum gpiod_flags flags
)
2413 struct gpio_desc
*desc
= NULL
;
2415 enum gpio_lookup_flags lookupflags
= 0;
2417 dev_dbg(dev
, "GPIO lookup for consumer %s\n", con_id
);
2420 /* Using device tree? */
2421 if (IS_ENABLED(CONFIG_OF
) && dev
->of_node
) {
2422 dev_dbg(dev
, "using device tree for GPIO lookup\n");
2423 desc
= of_find_gpio(dev
, con_id
, idx
, &lookupflags
);
2424 } else if (ACPI_COMPANION(dev
)) {
2425 dev_dbg(dev
, "using ACPI for GPIO lookup\n");
2426 desc
= acpi_find_gpio(dev
, con_id
, idx
, &lookupflags
);
2431 * Either we are not using DT or ACPI, or their lookup did not return
2432 * a result. In that case, use platform lookup as a fallback.
2434 if (!desc
|| desc
== ERR_PTR(-ENOENT
)) {
2435 dev_dbg(dev
, "using lookup tables for GPIO lookup\n");
2436 desc
= gpiod_find(dev
, con_id
, idx
, &lookupflags
);
2440 dev_dbg(dev
, "lookup for GPIO %s failed\n", con_id
);
2444 gpiod_parse_flags(desc
, lookupflags
);
2446 status
= gpiod_request(desc
, con_id
);
2448 return ERR_PTR(status
);
2450 status
= gpiod_configure_flags(desc
, con_id
, flags
);
2452 dev_dbg(dev
, "setup of GPIO %s failed\n", con_id
);
2454 return ERR_PTR(status
);
2459 EXPORT_SYMBOL_GPL(gpiod_get_index
);
2462 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2463 * @fwnode: handle of the firmware node
2464 * @propname: name of the firmware property representing the GPIO
2466 * This function can be used for drivers that get their configuration
2469 * Function properly finds the corresponding GPIO using whatever is the
2470 * underlying firmware interface and then makes sure that the GPIO
2471 * descriptor is requested before it is returned to the caller.
2473 * In case of error an ERR_PTR() is returned.
2475 struct gpio_desc
*fwnode_get_named_gpiod(struct fwnode_handle
*fwnode
,
2476 const char *propname
)
2478 struct gpio_desc
*desc
= ERR_PTR(-ENODEV
);
2479 bool active_low
= false;
2480 bool single_ended
= false;
2484 return ERR_PTR(-EINVAL
);
2486 if (is_of_node(fwnode
)) {
2487 enum of_gpio_flags flags
;
2489 desc
= of_get_named_gpiod_flags(to_of_node(fwnode
), propname
, 0,
2491 if (!IS_ERR(desc
)) {
2492 active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
2493 single_ended
= flags
& OF_GPIO_SINGLE_ENDED
;
2495 } else if (is_acpi_node(fwnode
)) {
2496 struct acpi_gpio_info info
;
2498 desc
= acpi_node_get_gpiod(fwnode
, propname
, 0, &info
);
2500 active_low
= info
.polarity
== GPIO_ACTIVE_LOW
;
2507 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2511 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2513 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2516 ret
= gpiod_request(desc
, NULL
);
2518 return ERR_PTR(ret
);
2522 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod
);
2525 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2527 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2528 * @con_id: function within the GPIO consumer
2529 * @index: index of the GPIO to obtain in the consumer
2530 * @flags: optional GPIO initialization flags
2532 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2533 * specified index was assigned to the requested function it will return NULL.
2534 * This is convenient for drivers that need to handle optional GPIOs.
2536 struct gpio_desc
*__must_check
gpiod_get_index_optional(struct device
*dev
,
2539 enum gpiod_flags flags
)
2541 struct gpio_desc
*desc
;
2543 desc
= gpiod_get_index(dev
, con_id
, index
, flags
);
2545 if (PTR_ERR(desc
) == -ENOENT
)
2551 EXPORT_SYMBOL_GPL(gpiod_get_index_optional
);
2554 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2555 * @desc: gpio whose value will be assigned
2556 * @name: gpio line name
2557 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2559 * @dflags: gpiod_flags - optional GPIO initialization flags
2561 int gpiod_hog(struct gpio_desc
*desc
, const char *name
,
2562 unsigned long lflags
, enum gpiod_flags dflags
)
2564 struct gpio_chip
*chip
;
2565 struct gpio_desc
*local_desc
;
2569 chip
= gpiod_to_chip(desc
);
2570 hwnum
= gpio_chip_hwgpio(desc
);
2572 gpiod_parse_flags(desc
, lflags
);
2574 local_desc
= gpiochip_request_own_desc(chip
, hwnum
, name
);
2575 if (IS_ERR(local_desc
)) {
2576 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2577 name
, chip
->label
, hwnum
);
2578 return PTR_ERR(local_desc
);
2581 status
= gpiod_configure_flags(desc
, name
, dflags
);
2583 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2584 name
, chip
->label
, hwnum
);
2585 gpiochip_free_own_desc(desc
);
2589 /* Mark GPIO as hogged so it can be identified and removed later */
2590 set_bit(FLAG_IS_HOGGED
, &desc
->flags
);
2592 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2593 desc_to_gpio(desc
), name
,
2594 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ? "output" : "input",
2595 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ?
2596 (dflags
&GPIOD_FLAGS_BIT_DIR_VAL
) ? "/high" : "/low":"");
2602 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2603 * @chip: gpio chip to act on
2605 * This is only used by of_gpiochip_remove to free hogged gpios
2607 static void gpiochip_free_hogs(struct gpio_chip
*chip
)
2611 for (id
= 0; id
< chip
->ngpio
; id
++) {
2612 if (test_bit(FLAG_IS_HOGGED
, &chip
->gpiodev
->descs
[id
].flags
))
2613 gpiochip_free_own_desc(&chip
->gpiodev
->descs
[id
]);
2618 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2619 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2620 * @con_id: function within the GPIO consumer
2621 * @flags: optional GPIO initialization flags
2623 * This function acquires all the GPIOs defined under a given function.
2625 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2626 * no GPIO has been assigned to the requested function, or another IS_ERR()
2627 * code if an error occurred while trying to acquire the GPIOs.
2629 struct gpio_descs
*__must_check
gpiod_get_array(struct device
*dev
,
2631 enum gpiod_flags flags
)
2633 struct gpio_desc
*desc
;
2634 struct gpio_descs
*descs
;
2637 count
= gpiod_count(dev
, con_id
);
2639 return ERR_PTR(count
);
2641 descs
= kzalloc(sizeof(*descs
) + sizeof(descs
->desc
[0]) * count
,
2644 return ERR_PTR(-ENOMEM
);
2646 for (descs
->ndescs
= 0; descs
->ndescs
< count
; ) {
2647 desc
= gpiod_get_index(dev
, con_id
, descs
->ndescs
, flags
);
2649 gpiod_put_array(descs
);
2650 return ERR_CAST(desc
);
2652 descs
->desc
[descs
->ndescs
] = desc
;
2657 EXPORT_SYMBOL_GPL(gpiod_get_array
);
2660 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2662 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2663 * @con_id: function within the GPIO consumer
2664 * @flags: optional GPIO initialization flags
2666 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2667 * assigned to the requested function it will return NULL.
2669 struct gpio_descs
*__must_check
gpiod_get_array_optional(struct device
*dev
,
2671 enum gpiod_flags flags
)
2673 struct gpio_descs
*descs
;
2675 descs
= gpiod_get_array(dev
, con_id
, flags
);
2676 if (IS_ERR(descs
) && (PTR_ERR(descs
) == -ENOENT
))
2681 EXPORT_SYMBOL_GPL(gpiod_get_array_optional
);
2684 * gpiod_put - dispose of a GPIO descriptor
2685 * @desc: GPIO descriptor to dispose of
2687 * No descriptor can be used after gpiod_put() has been called on it.
2689 void gpiod_put(struct gpio_desc
*desc
)
2693 EXPORT_SYMBOL_GPL(gpiod_put
);
2696 * gpiod_put_array - dispose of multiple GPIO descriptors
2697 * @descs: struct gpio_descs containing an array of descriptors
2699 void gpiod_put_array(struct gpio_descs
*descs
)
2703 for (i
= 0; i
< descs
->ndescs
; i
++)
2704 gpiod_put(descs
->desc
[i
]);
2708 EXPORT_SYMBOL_GPL(gpiod_put_array
);
2710 static int __init
gpiolib_dev_init(void)
2714 /* Register GPIO sysfs bus */
2715 ret
= bus_register(&gpio_bus_type
);
2717 pr_err("gpiolib: could not register GPIO bus type\n");
2721 ret
= alloc_chrdev_region(&gpio_devt
, 0, GPIO_DEV_MAX
, "gpiochip");
2723 pr_err("gpiolib: failed to allocate char dev region\n");
2724 bus_unregister(&gpio_bus_type
);
2728 core_initcall(gpiolib_dev_init
);
2730 #ifdef CONFIG_DEBUG_FS
2732 static void gpiolib_dbg_show(struct seq_file
*s
, struct gpio_device
*gdev
)
2735 struct gpio_chip
*chip
= gdev
->chip
;
2736 unsigned gpio
= gdev
->base
;
2737 struct gpio_desc
*gdesc
= &gdev
->descs
[0];
2741 for (i
= 0; i
< gdev
->ngpio
; i
++, gpio
++, gdesc
++) {
2742 if (!test_bit(FLAG_REQUESTED
, &gdesc
->flags
)) {
2744 seq_printf(s
, " gpio-%-3d (%-20.20s)\n",
2750 gpiod_get_direction(gdesc
);
2751 is_out
= test_bit(FLAG_IS_OUT
, &gdesc
->flags
);
2752 is_irq
= test_bit(FLAG_USED_AS_IRQ
, &gdesc
->flags
);
2753 seq_printf(s
, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2754 gpio
, gdesc
->name
? gdesc
->name
: "", gdesc
->label
,
2755 is_out
? "out" : "in ",
2757 ? (chip
->get(chip
, i
) ? "hi" : "lo")
2759 is_irq
? "IRQ" : " ");
2760 seq_printf(s
, "\n");
2764 static void *gpiolib_seq_start(struct seq_file
*s
, loff_t
*pos
)
2766 unsigned long flags
;
2767 struct gpio_device
*gdev
= NULL
;
2768 loff_t index
= *pos
;
2772 spin_lock_irqsave(&gpio_lock
, flags
);
2773 list_for_each_entry(gdev
, &gpio_devices
, list
)
2775 spin_unlock_irqrestore(&gpio_lock
, flags
);
2778 spin_unlock_irqrestore(&gpio_lock
, flags
);
2783 static void *gpiolib_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
2785 unsigned long flags
;
2786 struct gpio_device
*gdev
= v
;
2789 spin_lock_irqsave(&gpio_lock
, flags
);
2790 if (list_is_last(&gdev
->list
, &gpio_devices
))
2793 ret
= list_entry(gdev
->list
.next
, struct gpio_device
, list
);
2794 spin_unlock_irqrestore(&gpio_lock
, flags
);
2802 static void gpiolib_seq_stop(struct seq_file
*s
, void *v
)
2806 static int gpiolib_seq_show(struct seq_file
*s
, void *v
)
2808 struct gpio_device
*gdev
= v
;
2809 struct gpio_chip
*chip
= gdev
->chip
;
2810 struct device
*parent
;
2813 seq_printf(s
, "%s%s: (dangling chip)", (char *)s
->private,
2814 dev_name(&gdev
->dev
));
2818 seq_printf(s
, "%s%s: GPIOs %d-%d", (char *)s
->private,
2819 dev_name(&gdev
->dev
),
2820 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1);
2821 parent
= chip
->parent
;
2823 seq_printf(s
, ", parent: %s/%s",
2824 parent
->bus
? parent
->bus
->name
: "no-bus",
2827 seq_printf(s
, ", %s", chip
->label
);
2828 if (chip
->can_sleep
)
2829 seq_printf(s
, ", can sleep");
2830 seq_printf(s
, ":\n");
2833 chip
->dbg_show(s
, chip
);
2835 gpiolib_dbg_show(s
, gdev
);
2840 static const struct seq_operations gpiolib_seq_ops
= {
2841 .start
= gpiolib_seq_start
,
2842 .next
= gpiolib_seq_next
,
2843 .stop
= gpiolib_seq_stop
,
2844 .show
= gpiolib_seq_show
,
2847 static int gpiolib_open(struct inode
*inode
, struct file
*file
)
2849 return seq_open(file
, &gpiolib_seq_ops
);
2852 static const struct file_operations gpiolib_operations
= {
2853 .owner
= THIS_MODULE
,
2854 .open
= gpiolib_open
,
2856 .llseek
= seq_lseek
,
2857 .release
= seq_release
,
2860 static int __init
gpiolib_debugfs_init(void)
2862 /* /sys/kernel/debug/gpio */
2863 (void) debugfs_create_file("gpio", S_IFREG
| S_IRUGO
,
2864 NULL
, NULL
, &gpiolib_operations
);
2867 subsys_initcall(gpiolib_debugfs_init
);
2869 #endif /* DEBUG_FS */