1 #include <linux/bitops.h>
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/interrupt.h>
6 #include <linux/spinlock.h>
7 #include <linux/list.h>
8 #include <linux/device.h>
10 #include <linux/debugfs.h>
11 #include <linux/seq_file.h>
12 #include <linux/gpio.h>
13 #include <linux/of_gpio.h>
14 #include <linux/idr.h>
15 #include <linux/slab.h>
16 #include <linux/acpi.h>
17 #include <linux/gpio/driver.h>
18 #include <linux/gpio/machine.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <linux/anon_inodes.h>
25 #include <linux/file.h>
26 #include <linux/kfifo.h>
27 #include <linux/poll.h>
28 #include <linux/timekeeping.h>
29 #include <uapi/linux/gpio.h>
33 #define CREATE_TRACE_POINTS
34 #include <trace/events/gpio.h>
36 /* Implementation infrastructure for GPIO interfaces.
38 * The GPIO programming interface allows for inlining speed-critical
39 * get/set operations for common cases, so that access to SOC-integrated
40 * GPIOs can sometimes cost only an instruction or two per bit.
44 /* When debugging, extend minimal trust to callers and platform code.
45 * Also emit diagnostic messages that may help initial bringup, when
46 * board setup or driver bugs are most common.
48 * Otherwise, minimize overhead in what may be bitbanging codepaths.
51 #define extra_checks 1
53 #define extra_checks 0
56 /* Device and char device-related information */
57 static DEFINE_IDA(gpio_ida
);
58 static dev_t gpio_devt
;
59 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
60 static struct bus_type gpio_bus_type
= {
64 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
65 * While any GPIO is requested, its gpio_chip is not removable;
66 * each GPIO's "requested" flag serves as a lock and refcount.
68 DEFINE_SPINLOCK(gpio_lock
);
70 static DEFINE_MUTEX(gpio_lookup_lock
);
71 static LIST_HEAD(gpio_lookup_list
);
72 LIST_HEAD(gpio_devices
);
74 static void gpiochip_free_hogs(struct gpio_chip
*chip
);
75 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
);
76 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
);
77 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
);
79 static bool gpiolib_initialized
;
81 static inline void desc_set_label(struct gpio_desc
*d
, const char *label
)
87 * Convert a GPIO number to its descriptor
89 struct gpio_desc
*gpio_to_desc(unsigned gpio
)
91 struct gpio_device
*gdev
;
94 spin_lock_irqsave(&gpio_lock
, flags
);
96 list_for_each_entry(gdev
, &gpio_devices
, list
) {
97 if (gdev
->base
<= gpio
&&
98 gdev
->base
+ gdev
->ngpio
> gpio
) {
99 spin_unlock_irqrestore(&gpio_lock
, flags
);
100 return &gdev
->descs
[gpio
- gdev
->base
];
104 spin_unlock_irqrestore(&gpio_lock
, flags
);
106 if (!gpio_is_valid(gpio
))
107 WARN(1, "invalid GPIO %d\n", gpio
);
111 EXPORT_SYMBOL_GPL(gpio_to_desc
);
114 * Get the GPIO descriptor corresponding to the given hw number for this chip.
116 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
119 struct gpio_device
*gdev
= chip
->gpiodev
;
121 if (hwnum
>= gdev
->ngpio
)
122 return ERR_PTR(-EINVAL
);
124 return &gdev
->descs
[hwnum
];
128 * Convert a GPIO descriptor to the integer namespace.
129 * This should disappear in the future but is needed since we still
130 * use GPIO numbers for error messages and sysfs nodes
132 int desc_to_gpio(const struct gpio_desc
*desc
)
134 return desc
->gdev
->base
+ (desc
- &desc
->gdev
->descs
[0]);
136 EXPORT_SYMBOL_GPL(desc_to_gpio
);
140 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
141 * @desc: descriptor to return the chip of
143 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
145 if (!desc
|| !desc
->gdev
|| !desc
->gdev
->chip
)
147 return desc
->gdev
->chip
;
149 EXPORT_SYMBOL_GPL(gpiod_to_chip
);
151 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
152 static int gpiochip_find_base(int ngpio
)
154 struct gpio_device
*gdev
;
155 int base
= ARCH_NR_GPIOS
- ngpio
;
157 list_for_each_entry_reverse(gdev
, &gpio_devices
, list
) {
158 /* found a free space? */
159 if (gdev
->base
+ gdev
->ngpio
<= base
)
162 /* nope, check the space right before the chip */
163 base
= gdev
->base
- ngpio
;
166 if (gpio_is_valid(base
)) {
167 pr_debug("%s: found new base at %d\n", __func__
, base
);
170 pr_err("%s: cannot find free range\n", __func__
);
176 * gpiod_get_direction - return the current direction of a GPIO
177 * @desc: GPIO to get the direction of
179 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
181 * This function may sleep if gpiod_cansleep() is true.
183 int gpiod_get_direction(struct gpio_desc
*desc
)
185 struct gpio_chip
*chip
;
187 int status
= -EINVAL
;
189 chip
= gpiod_to_chip(desc
);
190 offset
= gpio_chip_hwgpio(desc
);
192 if (!chip
->get_direction
)
195 status
= chip
->get_direction(chip
, offset
);
197 /* GPIOF_DIR_IN, or other positive */
199 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
203 set_bit(FLAG_IS_OUT
, &desc
->flags
);
207 EXPORT_SYMBOL_GPL(gpiod_get_direction
);
210 * Add a new chip to the global chips list, keeping the list of chips sorted
211 * by range(means [base, base + ngpio - 1]) order.
213 * Return -EBUSY if the new chip overlaps with some other chip's integer
216 static int gpiodev_add_to_list(struct gpio_device
*gdev
)
218 struct gpio_device
*prev
, *next
;
220 if (list_empty(&gpio_devices
)) {
221 /* initial entry in list */
222 list_add_tail(&gdev
->list
, &gpio_devices
);
226 next
= list_entry(gpio_devices
.next
, struct gpio_device
, list
);
227 if (gdev
->base
+ gdev
->ngpio
<= next
->base
) {
228 /* add before first entry */
229 list_add(&gdev
->list
, &gpio_devices
);
233 prev
= list_entry(gpio_devices
.prev
, struct gpio_device
, list
);
234 if (prev
->base
+ prev
->ngpio
<= gdev
->base
) {
235 /* add behind last entry */
236 list_add_tail(&gdev
->list
, &gpio_devices
);
240 list_for_each_entry_safe(prev
, next
, &gpio_devices
, list
) {
241 /* at the end of the list */
242 if (&next
->list
== &gpio_devices
)
245 /* add between prev and next */
246 if (prev
->base
+ prev
->ngpio
<= gdev
->base
247 && gdev
->base
+ gdev
->ngpio
<= next
->base
) {
248 list_add(&gdev
->list
, &prev
->list
);
253 dev_err(&gdev
->dev
, "GPIO integer space overlap, cannot add chip\n");
258 * Convert a GPIO name to its descriptor
260 static struct gpio_desc
*gpio_name_to_desc(const char * const name
)
262 struct gpio_device
*gdev
;
265 spin_lock_irqsave(&gpio_lock
, flags
);
267 list_for_each_entry(gdev
, &gpio_devices
, list
) {
270 for (i
= 0; i
!= gdev
->ngpio
; ++i
) {
271 struct gpio_desc
*desc
= &gdev
->descs
[i
];
273 if (!desc
->name
|| !name
)
276 if (!strcmp(desc
->name
, name
)) {
277 spin_unlock_irqrestore(&gpio_lock
, flags
);
283 spin_unlock_irqrestore(&gpio_lock
, flags
);
289 * Takes the names from gc->names and checks if they are all unique. If they
290 * are, they are assigned to their gpio descriptors.
292 * Warning if one of the names is already used for a different GPIO.
294 static int gpiochip_set_desc_names(struct gpio_chip
*gc
)
296 struct gpio_device
*gdev
= gc
->gpiodev
;
302 /* First check all names if they are unique */
303 for (i
= 0; i
!= gc
->ngpio
; ++i
) {
304 struct gpio_desc
*gpio
;
306 gpio
= gpio_name_to_desc(gc
->names
[i
]);
309 "Detected name collision for GPIO name '%s'\n",
313 /* Then add all names to the GPIO descriptors */
314 for (i
= 0; i
!= gc
->ngpio
; ++i
)
315 gdev
->descs
[i
].name
= gc
->names
[i
];
321 * GPIO line handle management
325 * struct linehandle_state - contains the state of a userspace handle
326 * @gdev: the GPIO device the handle pertains to
327 * @label: consumer label used to tag descriptors
328 * @descs: the GPIO descriptors held by this handle
329 * @numdescs: the number of descriptors held in the descs array
331 struct linehandle_state
{
332 struct gpio_device
*gdev
;
334 struct gpio_desc
*descs
[GPIOHANDLES_MAX
];
338 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
339 (GPIOHANDLE_REQUEST_INPUT | \
340 GPIOHANDLE_REQUEST_OUTPUT | \
341 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
342 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
343 GPIOHANDLE_REQUEST_OPEN_SOURCE)
345 static long linehandle_ioctl(struct file
*filep
, unsigned int cmd
,
348 struct linehandle_state
*lh
= filep
->private_data
;
349 void __user
*ip
= (void __user
*)arg
;
350 struct gpiohandle_data ghd
;
353 if (cmd
== GPIOHANDLE_GET_LINE_VALUES_IOCTL
) {
356 memset(&ghd
, 0, sizeof(ghd
));
358 /* TODO: check if descriptors are really input */
359 for (i
= 0; i
< lh
->numdescs
; i
++) {
360 val
= gpiod_get_value_cansleep(lh
->descs
[i
]);
366 if (copy_to_user(ip
, &ghd
, sizeof(ghd
)))
370 } else if (cmd
== GPIOHANDLE_SET_LINE_VALUES_IOCTL
) {
371 int vals
[GPIOHANDLES_MAX
];
373 /* TODO: check if descriptors are really output */
374 if (copy_from_user(&ghd
, ip
, sizeof(ghd
)))
377 /* Clamp all values to [0,1] */
378 for (i
= 0; i
< lh
->numdescs
; i
++)
379 vals
[i
] = !!ghd
.values
[i
];
381 /* Reuse the array setting function */
382 gpiod_set_array_value_complex(false,
393 static long linehandle_ioctl_compat(struct file
*filep
, unsigned int cmd
,
396 return linehandle_ioctl(filep
, cmd
, (unsigned long)compat_ptr(arg
));
400 static int linehandle_release(struct inode
*inode
, struct file
*filep
)
402 struct linehandle_state
*lh
= filep
->private_data
;
403 struct gpio_device
*gdev
= lh
->gdev
;
406 for (i
= 0; i
< lh
->numdescs
; i
++)
407 gpiod_free(lh
->descs
[i
]);
410 put_device(&gdev
->dev
);
414 static const struct file_operations linehandle_fileops
= {
415 .release
= linehandle_release
,
416 .owner
= THIS_MODULE
,
417 .llseek
= noop_llseek
,
418 .unlocked_ioctl
= linehandle_ioctl
,
420 .compat_ioctl
= linehandle_ioctl_compat
,
424 static int linehandle_create(struct gpio_device
*gdev
, void __user
*ip
)
426 struct gpiohandle_request handlereq
;
427 struct linehandle_state
*lh
;
431 if (copy_from_user(&handlereq
, ip
, sizeof(handlereq
)))
433 if ((handlereq
.lines
== 0) || (handlereq
.lines
> GPIOHANDLES_MAX
))
436 lh
= kzalloc(sizeof(*lh
), GFP_KERNEL
);
440 get_device(&gdev
->dev
);
442 /* Make sure this is terminated */
443 handlereq
.consumer_label
[sizeof(handlereq
.consumer_label
)-1] = '\0';
444 if (strlen(handlereq
.consumer_label
)) {
445 lh
->label
= kstrdup(handlereq
.consumer_label
,
453 /* Request each GPIO */
454 for (i
= 0; i
< handlereq
.lines
; i
++) {
455 u32 offset
= handlereq
.lineoffsets
[i
];
456 u32 lflags
= handlereq
.flags
;
457 struct gpio_desc
*desc
;
459 if (offset
>= gdev
->ngpio
) {
464 /* Return an error if a unknown flag is set */
465 if (lflags
& ~GPIOHANDLE_REQUEST_VALID_FLAGS
) {
470 desc
= &gdev
->descs
[offset
];
471 ret
= gpiod_request(desc
, lh
->label
);
476 if (lflags
& GPIOHANDLE_REQUEST_ACTIVE_LOW
)
477 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
478 if (lflags
& GPIOHANDLE_REQUEST_OPEN_DRAIN
)
479 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
480 if (lflags
& GPIOHANDLE_REQUEST_OPEN_SOURCE
)
481 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
484 * Lines have to be requested explicitly for input
485 * or output, else the line will be treated "as is".
487 if (lflags
& GPIOHANDLE_REQUEST_OUTPUT
) {
488 int val
= !!handlereq
.default_values
[i
];
490 ret
= gpiod_direction_output(desc
, val
);
493 } else if (lflags
& GPIOHANDLE_REQUEST_INPUT
) {
494 ret
= gpiod_direction_input(desc
);
498 dev_dbg(&gdev
->dev
, "registered chardev handle for line %d\n",
501 /* Let i point at the last handle */
503 lh
->numdescs
= handlereq
.lines
;
505 fd
= get_unused_fd_flags(O_RDONLY
| O_CLOEXEC
);
511 file
= anon_inode_getfile("gpio-linehandle",
514 O_RDONLY
| O_CLOEXEC
);
517 goto out_put_unused_fd
;
521 if (copy_to_user(ip
, &handlereq
, sizeof(handlereq
))) {
523 * fput() will trigger the release() callback, so do not go onto
524 * the regular error cleanup path here.
531 fd_install(fd
, file
);
533 dev_dbg(&gdev
->dev
, "registered chardev handle for %d lines\n",
542 gpiod_free(lh
->descs
[i
]);
546 put_device(&gdev
->dev
);
551 * GPIO line event management
555 * struct lineevent_state - contains the state of a userspace event
556 * @gdev: the GPIO device the event pertains to
557 * @label: consumer label used to tag descriptors
558 * @desc: the GPIO descriptor held by this event
559 * @eflags: the event flags this line was requested with
560 * @irq: the interrupt that trigger in response to events on this GPIO
561 * @wait: wait queue that handles blocking reads of events
562 * @events: KFIFO for the GPIO events
563 * @read_lock: mutex lock to protect reads from colliding with adding
564 * new events to the FIFO
566 struct lineevent_state
{
567 struct gpio_device
*gdev
;
569 struct gpio_desc
*desc
;
572 wait_queue_head_t wait
;
573 DECLARE_KFIFO(events
, struct gpioevent_data
, 16);
574 struct mutex read_lock
;
577 #define GPIOEVENT_REQUEST_VALID_FLAGS \
578 (GPIOEVENT_REQUEST_RISING_EDGE | \
579 GPIOEVENT_REQUEST_FALLING_EDGE)
581 static unsigned int lineevent_poll(struct file
*filep
,
582 struct poll_table_struct
*wait
)
584 struct lineevent_state
*le
= filep
->private_data
;
585 unsigned int events
= 0;
587 poll_wait(filep
, &le
->wait
, wait
);
589 if (!kfifo_is_empty(&le
->events
))
590 events
= POLLIN
| POLLRDNORM
;
596 static ssize_t
lineevent_read(struct file
*filep
,
601 struct lineevent_state
*le
= filep
->private_data
;
605 if (count
< sizeof(struct gpioevent_data
))
609 if (kfifo_is_empty(&le
->events
)) {
610 if (filep
->f_flags
& O_NONBLOCK
)
613 ret
= wait_event_interruptible(le
->wait
,
614 !kfifo_is_empty(&le
->events
));
619 if (mutex_lock_interruptible(&le
->read_lock
))
621 ret
= kfifo_to_user(&le
->events
, buf
, count
, &copied
);
622 mutex_unlock(&le
->read_lock
);
628 * If we couldn't read anything from the fifo (a different
629 * thread might have been faster) we either return -EAGAIN if
630 * the file descriptor is non-blocking, otherwise we go back to
631 * sleep and wait for more data to arrive.
633 if (copied
== 0 && (filep
->f_flags
& O_NONBLOCK
))
636 } while (copied
== 0);
641 static int lineevent_release(struct inode
*inode
, struct file
*filep
)
643 struct lineevent_state
*le
= filep
->private_data
;
644 struct gpio_device
*gdev
= le
->gdev
;
646 free_irq(le
->irq
, le
);
647 gpiod_free(le
->desc
);
650 put_device(&gdev
->dev
);
654 static long lineevent_ioctl(struct file
*filep
, unsigned int cmd
,
657 struct lineevent_state
*le
= filep
->private_data
;
658 void __user
*ip
= (void __user
*)arg
;
659 struct gpiohandle_data ghd
;
662 * We can get the value for an event line but not set it,
663 * because it is input by definition.
665 if (cmd
== GPIOHANDLE_GET_LINE_VALUES_IOCTL
) {
668 memset(&ghd
, 0, sizeof(ghd
));
670 val
= gpiod_get_value_cansleep(le
->desc
);
675 if (copy_to_user(ip
, &ghd
, sizeof(ghd
)))
684 static long lineevent_ioctl_compat(struct file
*filep
, unsigned int cmd
,
687 return lineevent_ioctl(filep
, cmd
, (unsigned long)compat_ptr(arg
));
691 static const struct file_operations lineevent_fileops
= {
692 .release
= lineevent_release
,
693 .read
= lineevent_read
,
694 .poll
= lineevent_poll
,
695 .owner
= THIS_MODULE
,
696 .llseek
= noop_llseek
,
697 .unlocked_ioctl
= lineevent_ioctl
,
699 .compat_ioctl
= lineevent_ioctl_compat
,
703 static irqreturn_t
lineevent_irq_thread(int irq
, void *p
)
705 struct lineevent_state
*le
= p
;
706 struct gpioevent_data ge
;
709 ge
.timestamp
= ktime_get_real_ns();
711 if (le
->eflags
& GPIOEVENT_REQUEST_BOTH_EDGES
) {
712 int level
= gpiod_get_value_cansleep(le
->desc
);
715 /* Emit low-to-high event */
716 ge
.id
= GPIOEVENT_EVENT_RISING_EDGE
;
718 /* Emit high-to-low event */
719 ge
.id
= GPIOEVENT_EVENT_FALLING_EDGE
;
720 } else if (le
->eflags
& GPIOEVENT_REQUEST_RISING_EDGE
) {
721 /* Emit low-to-high event */
722 ge
.id
= GPIOEVENT_EVENT_RISING_EDGE
;
723 } else if (le
->eflags
& GPIOEVENT_REQUEST_FALLING_EDGE
) {
724 /* Emit high-to-low event */
725 ge
.id
= GPIOEVENT_EVENT_FALLING_EDGE
;
730 ret
= kfifo_put(&le
->events
, ge
);
732 wake_up_poll(&le
->wait
, POLLIN
);
737 static int lineevent_create(struct gpio_device
*gdev
, void __user
*ip
)
739 struct gpioevent_request eventreq
;
740 struct lineevent_state
*le
;
741 struct gpio_desc
*desc
;
750 if (copy_from_user(&eventreq
, ip
, sizeof(eventreq
)))
753 le
= kzalloc(sizeof(*le
), GFP_KERNEL
);
757 get_device(&gdev
->dev
);
759 /* Make sure this is terminated */
760 eventreq
.consumer_label
[sizeof(eventreq
.consumer_label
)-1] = '\0';
761 if (strlen(eventreq
.consumer_label
)) {
762 le
->label
= kstrdup(eventreq
.consumer_label
,
770 offset
= eventreq
.lineoffset
;
771 lflags
= eventreq
.handleflags
;
772 eflags
= eventreq
.eventflags
;
774 if (offset
>= gdev
->ngpio
) {
779 /* Return an error if a unknown flag is set */
780 if ((lflags
& ~GPIOHANDLE_REQUEST_VALID_FLAGS
) ||
781 (eflags
& ~GPIOEVENT_REQUEST_VALID_FLAGS
)) {
786 /* This is just wrong: we don't look for events on output lines */
787 if (lflags
& GPIOHANDLE_REQUEST_OUTPUT
) {
792 desc
= &gdev
->descs
[offset
];
793 ret
= gpiod_request(desc
, le
->label
);
799 if (lflags
& GPIOHANDLE_REQUEST_ACTIVE_LOW
)
800 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
801 if (lflags
& GPIOHANDLE_REQUEST_OPEN_DRAIN
)
802 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
803 if (lflags
& GPIOHANDLE_REQUEST_OPEN_SOURCE
)
804 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
806 ret
= gpiod_direction_input(desc
);
810 le
->irq
= gpiod_to_irq(desc
);
816 if (eflags
& GPIOEVENT_REQUEST_RISING_EDGE
)
817 irqflags
|= IRQF_TRIGGER_RISING
;
818 if (eflags
& GPIOEVENT_REQUEST_FALLING_EDGE
)
819 irqflags
|= IRQF_TRIGGER_FALLING
;
820 irqflags
|= IRQF_ONESHOT
;
821 irqflags
|= IRQF_SHARED
;
823 INIT_KFIFO(le
->events
);
824 init_waitqueue_head(&le
->wait
);
825 mutex_init(&le
->read_lock
);
827 /* Request a thread to read the events */
828 ret
= request_threaded_irq(le
->irq
,
830 lineevent_irq_thread
,
837 fd
= get_unused_fd_flags(O_RDONLY
| O_CLOEXEC
);
843 file
= anon_inode_getfile("gpio-event",
846 O_RDONLY
| O_CLOEXEC
);
849 goto out_put_unused_fd
;
853 if (copy_to_user(ip
, &eventreq
, sizeof(eventreq
))) {
855 * fput() will trigger the release() callback, so do not go onto
856 * the regular error cleanup path here.
863 fd_install(fd
, file
);
870 free_irq(le
->irq
, le
);
872 gpiod_free(le
->desc
);
877 put_device(&gdev
->dev
);
882 * gpio_ioctl() - ioctl handler for the GPIO chardev
884 static long gpio_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
886 struct gpio_device
*gdev
= filp
->private_data
;
887 struct gpio_chip
*chip
= gdev
->chip
;
888 void __user
*ip
= (void __user
*)arg
;
890 /* We fail any subsequent ioctl():s when the chip is gone */
894 /* Fill in the struct and pass to userspace */
895 if (cmd
== GPIO_GET_CHIPINFO_IOCTL
) {
896 struct gpiochip_info chipinfo
;
898 memset(&chipinfo
, 0, sizeof(chipinfo
));
900 strncpy(chipinfo
.name
, dev_name(&gdev
->dev
),
901 sizeof(chipinfo
.name
));
902 chipinfo
.name
[sizeof(chipinfo
.name
)-1] = '\0';
903 strncpy(chipinfo
.label
, gdev
->label
,
904 sizeof(chipinfo
.label
));
905 chipinfo
.label
[sizeof(chipinfo
.label
)-1] = '\0';
906 chipinfo
.lines
= gdev
->ngpio
;
907 if (copy_to_user(ip
, &chipinfo
, sizeof(chipinfo
)))
910 } else if (cmd
== GPIO_GET_LINEINFO_IOCTL
) {
911 struct gpioline_info lineinfo
;
912 struct gpio_desc
*desc
;
914 if (copy_from_user(&lineinfo
, ip
, sizeof(lineinfo
)))
916 if (lineinfo
.line_offset
>= gdev
->ngpio
)
919 desc
= &gdev
->descs
[lineinfo
.line_offset
];
921 strncpy(lineinfo
.name
, desc
->name
,
922 sizeof(lineinfo
.name
));
923 lineinfo
.name
[sizeof(lineinfo
.name
)-1] = '\0';
925 lineinfo
.name
[0] = '\0';
928 strncpy(lineinfo
.consumer
, desc
->label
,
929 sizeof(lineinfo
.consumer
));
930 lineinfo
.consumer
[sizeof(lineinfo
.consumer
)-1] = '\0';
932 lineinfo
.consumer
[0] = '\0';
936 * Userspace only need to know that the kernel is using
937 * this GPIO so it can't use it.
940 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) ||
941 test_bit(FLAG_IS_HOGGED
, &desc
->flags
) ||
942 test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
) ||
943 test_bit(FLAG_EXPORT
, &desc
->flags
) ||
944 test_bit(FLAG_SYSFS
, &desc
->flags
))
945 lineinfo
.flags
|= GPIOLINE_FLAG_KERNEL
;
946 if (test_bit(FLAG_IS_OUT
, &desc
->flags
))
947 lineinfo
.flags
|= GPIOLINE_FLAG_IS_OUT
;
948 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
949 lineinfo
.flags
|= GPIOLINE_FLAG_ACTIVE_LOW
;
950 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
951 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_DRAIN
;
952 if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
953 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_SOURCE
;
955 if (copy_to_user(ip
, &lineinfo
, sizeof(lineinfo
)))
958 } else if (cmd
== GPIO_GET_LINEHANDLE_IOCTL
) {
959 return linehandle_create(gdev
, ip
);
960 } else if (cmd
== GPIO_GET_LINEEVENT_IOCTL
) {
961 return lineevent_create(gdev
, ip
);
967 static long gpio_ioctl_compat(struct file
*filp
, unsigned int cmd
,
970 return gpio_ioctl(filp
, cmd
, (unsigned long)compat_ptr(arg
));
975 * gpio_chrdev_open() - open the chardev for ioctl operations
976 * @inode: inode for this chardev
977 * @filp: file struct for storing private data
978 * Returns 0 on success
980 static int gpio_chrdev_open(struct inode
*inode
, struct file
*filp
)
982 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
983 struct gpio_device
, chrdev
);
985 /* Fail on open if the backing gpiochip is gone */
988 get_device(&gdev
->dev
);
989 filp
->private_data
= gdev
;
991 return nonseekable_open(inode
, filp
);
995 * gpio_chrdev_release() - close chardev after ioctl operations
996 * @inode: inode for this chardev
997 * @filp: file struct for storing private data
998 * Returns 0 on success
1000 static int gpio_chrdev_release(struct inode
*inode
, struct file
*filp
)
1002 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
1003 struct gpio_device
, chrdev
);
1005 put_device(&gdev
->dev
);
1010 static const struct file_operations gpio_fileops
= {
1011 .release
= gpio_chrdev_release
,
1012 .open
= gpio_chrdev_open
,
1013 .owner
= THIS_MODULE
,
1014 .llseek
= no_llseek
,
1015 .unlocked_ioctl
= gpio_ioctl
,
1016 #ifdef CONFIG_COMPAT
1017 .compat_ioctl
= gpio_ioctl_compat
,
1021 static void gpiodevice_release(struct device
*dev
)
1023 struct gpio_device
*gdev
= dev_get_drvdata(dev
);
1025 list_del(&gdev
->list
);
1026 ida_simple_remove(&gpio_ida
, gdev
->id
);
1032 static int gpiochip_setup_dev(struct gpio_device
*gdev
)
1036 cdev_init(&gdev
->chrdev
, &gpio_fileops
);
1037 gdev
->chrdev
.owner
= THIS_MODULE
;
1038 gdev
->chrdev
.kobj
.parent
= &gdev
->dev
.kobj
;
1039 gdev
->dev
.devt
= MKDEV(MAJOR(gpio_devt
), gdev
->id
);
1040 status
= cdev_add(&gdev
->chrdev
, gdev
->dev
.devt
, 1);
1042 chip_warn(gdev
->chip
, "failed to add char device %d:%d\n",
1043 MAJOR(gpio_devt
), gdev
->id
);
1045 chip_dbg(gdev
->chip
, "added GPIO chardev (%d:%d)\n",
1046 MAJOR(gpio_devt
), gdev
->id
);
1047 status
= device_add(&gdev
->dev
);
1049 goto err_remove_chardev
;
1051 status
= gpiochip_sysfs_register(gdev
);
1053 goto err_remove_device
;
1055 /* From this point, the .release() function cleans up gpio_device */
1056 gdev
->dev
.release
= gpiodevice_release
;
1057 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1058 __func__
, gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
1059 dev_name(&gdev
->dev
), gdev
->chip
->label
? : "generic");
1064 device_del(&gdev
->dev
);
1066 cdev_del(&gdev
->chrdev
);
1070 static void gpiochip_setup_devs(void)
1072 struct gpio_device
*gdev
;
1075 list_for_each_entry(gdev
, &gpio_devices
, list
) {
1076 err
= gpiochip_setup_dev(gdev
);
1078 pr_err("%s: Failed to initialize gpio device (%d)\n",
1079 dev_name(&gdev
->dev
), err
);
1084 * gpiochip_add_data() - register a gpio_chip
1085 * @chip: the chip to register, with chip->base initialized
1086 * Context: potentially before irqs will work
1088 * Returns a negative errno if the chip can't be registered, such as
1089 * because the chip->base is invalid or already associated with a
1090 * different chip. Otherwise it returns zero as a success code.
1092 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1093 * can be freely used, the chip->parent device must be registered before
1094 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1095 * for GPIOs will fail rudely.
1097 * gpiochip_add_data() must only be called after gpiolib initialization,
1098 * ie after core_initcall().
1100 * If chip->base is negative, this requests dynamic assignment of
1101 * a range of valid GPIOs.
1103 int gpiochip_add_data(struct gpio_chip
*chip
, void *data
)
1105 unsigned long flags
;
1108 int base
= chip
->base
;
1109 struct gpio_device
*gdev
;
1112 * First: allocate and populate the internal stat container, and
1113 * set up the struct device.
1115 gdev
= kzalloc(sizeof(*gdev
), GFP_KERNEL
);
1118 gdev
->dev
.bus
= &gpio_bus_type
;
1120 chip
->gpiodev
= gdev
;
1122 gdev
->dev
.parent
= chip
->parent
;
1123 gdev
->dev
.of_node
= chip
->parent
->of_node
;
1126 #ifdef CONFIG_OF_GPIO
1127 /* If the gpiochip has an assigned OF node this takes precedence */
1129 gdev
->dev
.of_node
= chip
->of_node
;
1132 gdev
->id
= ida_simple_get(&gpio_ida
, 0, 0, GFP_KERNEL
);
1137 dev_set_name(&gdev
->dev
, "gpiochip%d", gdev
->id
);
1138 device_initialize(&gdev
->dev
);
1139 dev_set_drvdata(&gdev
->dev
, gdev
);
1140 if (chip
->parent
&& chip
->parent
->driver
)
1141 gdev
->owner
= chip
->parent
->driver
->owner
;
1142 else if (chip
->owner
)
1143 /* TODO: remove chip->owner */
1144 gdev
->owner
= chip
->owner
;
1146 gdev
->owner
= THIS_MODULE
;
1148 gdev
->descs
= kcalloc(chip
->ngpio
, sizeof(gdev
->descs
[0]), GFP_KERNEL
);
1154 if (chip
->ngpio
== 0) {
1155 chip_err(chip
, "tried to insert a GPIO chip with zero lines\n");
1157 goto err_free_descs
;
1161 gdev
->label
= kstrdup(chip
->label
, GFP_KERNEL
);
1163 gdev
->label
= kstrdup("unknown", GFP_KERNEL
);
1166 goto err_free_descs
;
1169 gdev
->ngpio
= chip
->ngpio
;
1172 spin_lock_irqsave(&gpio_lock
, flags
);
1175 * TODO: this allocates a Linux GPIO number base in the global
1176 * GPIO numberspace for this chip. In the long run we want to
1177 * get *rid* of this numberspace and use only descriptors, but
1178 * it may be a pipe dream. It will not happen before we get rid
1179 * of the sysfs interface anyways.
1182 base
= gpiochip_find_base(chip
->ngpio
);
1185 spin_unlock_irqrestore(&gpio_lock
, flags
);
1186 goto err_free_label
;
1189 * TODO: it should not be necessary to reflect the assigned
1190 * base outside of the GPIO subsystem. Go over drivers and
1191 * see if anyone makes use of this, else drop this and assign
1198 status
= gpiodev_add_to_list(gdev
);
1200 spin_unlock_irqrestore(&gpio_lock
, flags
);
1201 goto err_free_label
;
1204 spin_unlock_irqrestore(&gpio_lock
, flags
);
1206 for (i
= 0; i
< chip
->ngpio
; i
++) {
1207 struct gpio_desc
*desc
= &gdev
->descs
[i
];
1211 * REVISIT: most hardware initializes GPIOs as inputs
1212 * (often with pullups enabled) so power usage is
1213 * minimized. Linux code should set the gpio direction
1214 * first thing; but until it does, and in case
1215 * chip->get_direction is not set, we may expose the
1216 * wrong direction in sysfs.
1219 if (chip
->get_direction
) {
1221 * If we have .get_direction, set up the initial
1222 * direction flag from the hardware.
1224 int dir
= chip
->get_direction(chip
, i
);
1227 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1228 } else if (!chip
->direction_input
) {
1230 * If the chip lacks the .direction_input callback
1231 * we logically assume all lines are outputs.
1233 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1237 #ifdef CONFIG_PINCTRL
1238 INIT_LIST_HEAD(&gdev
->pin_ranges
);
1241 status
= gpiochip_set_desc_names(chip
);
1243 goto err_remove_from_list
;
1245 status
= gpiochip_irqchip_init_valid_mask(chip
);
1247 goto err_remove_from_list
;
1249 status
= of_gpiochip_add(chip
);
1251 goto err_remove_chip
;
1253 acpi_gpiochip_add(chip
);
1256 * By first adding the chardev, and then adding the device,
1257 * we get a device node entry in sysfs under
1258 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1259 * coldplug of device nodes and other udev business.
1260 * We can do this only if gpiolib has been initialized.
1261 * Otherwise, defer until later.
1263 if (gpiolib_initialized
) {
1264 status
= gpiochip_setup_dev(gdev
);
1266 goto err_remove_chip
;
1271 acpi_gpiochip_remove(chip
);
1272 gpiochip_free_hogs(chip
);
1273 of_gpiochip_remove(chip
);
1274 gpiochip_irqchip_free_valid_mask(chip
);
1275 err_remove_from_list
:
1276 spin_lock_irqsave(&gpio_lock
, flags
);
1277 list_del(&gdev
->list
);
1278 spin_unlock_irqrestore(&gpio_lock
, flags
);
1284 ida_simple_remove(&gpio_ida
, gdev
->id
);
1285 /* failures here can mean systems won't boot... */
1286 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__
,
1287 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
1288 chip
->label
? : "generic");
1292 EXPORT_SYMBOL_GPL(gpiochip_add_data
);
1295 * gpiochip_get_data() - get per-subdriver data for the chip
1297 void *gpiochip_get_data(struct gpio_chip
*chip
)
1299 return chip
->gpiodev
->data
;
1301 EXPORT_SYMBOL_GPL(gpiochip_get_data
);
1304 * gpiochip_remove() - unregister a gpio_chip
1305 * @chip: the chip to unregister
1307 * A gpio_chip with any GPIOs still requested may not be removed.
1309 void gpiochip_remove(struct gpio_chip
*chip
)
1311 struct gpio_device
*gdev
= chip
->gpiodev
;
1312 struct gpio_desc
*desc
;
1313 unsigned long flags
;
1315 bool requested
= false;
1317 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1318 gpiochip_sysfs_unregister(gdev
);
1319 /* Numb the device, cancelling all outstanding operations */
1321 gpiochip_irqchip_remove(chip
);
1322 acpi_gpiochip_remove(chip
);
1323 gpiochip_remove_pin_ranges(chip
);
1324 gpiochip_free_hogs(chip
);
1325 of_gpiochip_remove(chip
);
1327 * We accept no more calls into the driver from this point, so
1328 * NULL the driver data pointer
1332 spin_lock_irqsave(&gpio_lock
, flags
);
1333 for (i
= 0; i
< gdev
->ngpio
; i
++) {
1334 desc
= &gdev
->descs
[i
];
1335 if (test_bit(FLAG_REQUESTED
, &desc
->flags
))
1338 spin_unlock_irqrestore(&gpio_lock
, flags
);
1341 dev_crit(&gdev
->dev
,
1342 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1345 * The gpiochip side puts its use of the device to rest here:
1346 * if there are no userspace clients, the chardev and device will
1347 * be removed, else it will be dangling until the last user is
1350 cdev_del(&gdev
->chrdev
);
1351 device_del(&gdev
->dev
);
1352 put_device(&gdev
->dev
);
1354 EXPORT_SYMBOL_GPL(gpiochip_remove
);
1356 static void devm_gpio_chip_release(struct device
*dev
, void *res
)
1358 struct gpio_chip
*chip
= *(struct gpio_chip
**)res
;
1360 gpiochip_remove(chip
);
1363 static int devm_gpio_chip_match(struct device
*dev
, void *res
, void *data
)
1366 struct gpio_chip
**r
= res
;
1377 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1378 * @dev: the device pointer on which irq_chip belongs to.
1379 * @chip: the chip to register, with chip->base initialized
1380 * Context: potentially before irqs will work
1382 * Returns a negative errno if the chip can't be registered, such as
1383 * because the chip->base is invalid or already associated with a
1384 * different chip. Otherwise it returns zero as a success code.
1386 * The gpio chip automatically be released when the device is unbound.
1388 int devm_gpiochip_add_data(struct device
*dev
, struct gpio_chip
*chip
,
1391 struct gpio_chip
**ptr
;
1394 ptr
= devres_alloc(devm_gpio_chip_release
, sizeof(*ptr
),
1399 ret
= gpiochip_add_data(chip
, data
);
1406 devres_add(dev
, ptr
);
1410 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data
);
1413 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1414 * @dev: device for which which resource was allocated
1415 * @chip: the chip to remove
1417 * A gpio_chip with any GPIOs still requested may not be removed.
1419 void devm_gpiochip_remove(struct device
*dev
, struct gpio_chip
*chip
)
1423 ret
= devres_release(dev
, devm_gpio_chip_release
,
1424 devm_gpio_chip_match
, chip
);
1427 EXPORT_SYMBOL_GPL(devm_gpiochip_remove
);
1430 * gpiochip_find() - iterator for locating a specific gpio_chip
1431 * @data: data to pass to match function
1432 * @callback: Callback function to check gpio_chip
1434 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1435 * determined by a user supplied @match callback. The callback should return
1436 * 0 if the device doesn't match and non-zero if it does. If the callback is
1437 * non-zero, this function will return to the caller and not iterate over any
1440 struct gpio_chip
*gpiochip_find(void *data
,
1441 int (*match
)(struct gpio_chip
*chip
,
1444 struct gpio_device
*gdev
;
1445 struct gpio_chip
*chip
= NULL
;
1446 unsigned long flags
;
1448 spin_lock_irqsave(&gpio_lock
, flags
);
1449 list_for_each_entry(gdev
, &gpio_devices
, list
)
1450 if (gdev
->chip
&& match(gdev
->chip
, data
)) {
1455 spin_unlock_irqrestore(&gpio_lock
, flags
);
1459 EXPORT_SYMBOL_GPL(gpiochip_find
);
1461 static int gpiochip_match_name(struct gpio_chip
*chip
, void *data
)
1463 const char *name
= data
;
1465 return !strcmp(chip
->label
, name
);
1468 static struct gpio_chip
*find_chip_by_name(const char *name
)
1470 return gpiochip_find((void *)name
, gpiochip_match_name
);
1473 #ifdef CONFIG_GPIOLIB_IRQCHIP
1476 * The following is irqchip helper code for gpiochips.
1479 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
)
1483 if (!gpiochip
->irq_need_valid_mask
)
1486 gpiochip
->irq_valid_mask
= kcalloc(BITS_TO_LONGS(gpiochip
->ngpio
),
1487 sizeof(long), GFP_KERNEL
);
1488 if (!gpiochip
->irq_valid_mask
)
1491 /* Assume by default all GPIOs are valid */
1492 for (i
= 0; i
< gpiochip
->ngpio
; i
++)
1493 set_bit(i
, gpiochip
->irq_valid_mask
);
1498 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
)
1500 kfree(gpiochip
->irq_valid_mask
);
1501 gpiochip
->irq_valid_mask
= NULL
;
1504 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip
*gpiochip
,
1505 unsigned int offset
)
1507 /* No mask means all valid */
1508 if (likely(!gpiochip
->irq_valid_mask
))
1510 return test_bit(offset
, gpiochip
->irq_valid_mask
);
1514 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1515 * @gpiochip: the gpiochip to set the irqchip chain to
1516 * @irqchip: the irqchip to chain to the gpiochip
1517 * @parent_irq: the irq number corresponding to the parent IRQ for this
1519 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1520 * coming out of the gpiochip. If the interrupt is nested rather than
1521 * cascaded, pass NULL in this handler argument
1523 static void gpiochip_set_cascaded_irqchip(struct gpio_chip
*gpiochip
,
1524 struct irq_chip
*irqchip
,
1526 irq_flow_handler_t parent_handler
)
1528 unsigned int offset
;
1530 if (!gpiochip
->irqdomain
) {
1531 chip_err(gpiochip
, "called %s before setting up irqchip\n",
1536 if (parent_handler
) {
1537 if (gpiochip
->can_sleep
) {
1539 "you cannot have chained interrupts on a "
1540 "chip that may sleep\n");
1544 * The parent irqchip is already using the chip_data for this
1545 * irqchip, so our callbacks simply use the handler_data.
1547 irq_set_chained_handler_and_data(parent_irq
, parent_handler
,
1550 gpiochip
->irq_chained_parent
= parent_irq
;
1553 /* Set the parent IRQ for all affected IRQs */
1554 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1555 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1557 irq_set_parent(irq_find_mapping(gpiochip
->irqdomain
, offset
),
1563 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1564 * @gpiochip: the gpiochip to set the irqchip chain to
1565 * @irqchip: the irqchip to chain to the gpiochip
1566 * @parent_irq: the irq number corresponding to the parent IRQ for this
1568 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1569 * coming out of the gpiochip. If the interrupt is nested rather than
1570 * cascaded, pass NULL in this handler argument
1572 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
1573 struct irq_chip
*irqchip
,
1575 irq_flow_handler_t parent_handler
)
1577 gpiochip_set_cascaded_irqchip(gpiochip
, irqchip
, parent_irq
,
1580 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip
);
1583 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1584 * @gpiochip: the gpiochip to set the irqchip nested handler to
1585 * @irqchip: the irqchip to nest to the gpiochip
1586 * @parent_irq: the irq number corresponding to the parent IRQ for this
1589 void gpiochip_set_nested_irqchip(struct gpio_chip
*gpiochip
,
1590 struct irq_chip
*irqchip
,
1593 if (!gpiochip
->irq_nested
) {
1594 chip_err(gpiochip
, "tried to nest a chained gpiochip\n");
1597 gpiochip_set_cascaded_irqchip(gpiochip
, irqchip
, parent_irq
,
1600 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip
);
1603 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1604 * @d: the irqdomain used by this irqchip
1605 * @irq: the global irq number used by this GPIO irqchip irq
1606 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1608 * This function will set up the mapping for a certain IRQ line on a
1609 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1610 * stored inside the gpiochip.
1612 static int gpiochip_irq_map(struct irq_domain
*d
, unsigned int irq
,
1613 irq_hw_number_t hwirq
)
1615 struct gpio_chip
*chip
= d
->host_data
;
1617 irq_set_chip_data(irq
, chip
);
1619 * This lock class tells lockdep that GPIO irqs are in a different
1620 * category than their parents, so it won't report false recursion.
1622 irq_set_lockdep_class(irq
, chip
->lock_key
);
1623 irq_set_chip_and_handler(irq
, chip
->irqchip
, chip
->irq_handler
);
1624 /* Chips that use nested thread handlers have them marked */
1625 if (chip
->irq_nested
)
1626 irq_set_nested_thread(irq
, 1);
1627 irq_set_noprobe(irq
);
1630 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1631 * is passed as default type.
1633 if (chip
->irq_default_type
!= IRQ_TYPE_NONE
)
1634 irq_set_irq_type(irq
, chip
->irq_default_type
);
1639 static void gpiochip_irq_unmap(struct irq_domain
*d
, unsigned int irq
)
1641 struct gpio_chip
*chip
= d
->host_data
;
1643 if (chip
->irq_nested
)
1644 irq_set_nested_thread(irq
, 0);
1645 irq_set_chip_and_handler(irq
, NULL
, NULL
);
1646 irq_set_chip_data(irq
, NULL
);
1649 static const struct irq_domain_ops gpiochip_domain_ops
= {
1650 .map
= gpiochip_irq_map
,
1651 .unmap
= gpiochip_irq_unmap
,
1652 /* Virtually all GPIO irqchips are twocell:ed */
1653 .xlate
= irq_domain_xlate_twocell
,
1656 static int gpiochip_irq_reqres(struct irq_data
*d
)
1658 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1660 if (!try_module_get(chip
->gpiodev
->owner
))
1663 if (gpiochip_lock_as_irq(chip
, d
->hwirq
)) {
1665 "unable to lock HW IRQ %lu for IRQ\n",
1667 module_put(chip
->gpiodev
->owner
);
1673 static void gpiochip_irq_relres(struct irq_data
*d
)
1675 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1677 gpiochip_unlock_as_irq(chip
, d
->hwirq
);
1678 module_put(chip
->gpiodev
->owner
);
1681 static int gpiochip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
1683 return irq_find_mapping(chip
->irqdomain
, offset
);
1687 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1688 * @gpiochip: the gpiochip to remove the irqchip from
1690 * This is called only from gpiochip_remove()
1692 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
)
1694 unsigned int offset
;
1696 acpi_gpiochip_free_interrupts(gpiochip
);
1698 if (gpiochip
->irq_chained_parent
) {
1699 irq_set_chained_handler(gpiochip
->irq_chained_parent
, NULL
);
1700 irq_set_handler_data(gpiochip
->irq_chained_parent
, NULL
);
1703 /* Remove all IRQ mappings and delete the domain */
1704 if (gpiochip
->irqdomain
) {
1705 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1706 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1708 irq_dispose_mapping(
1709 irq_find_mapping(gpiochip
->irqdomain
, offset
));
1711 irq_domain_remove(gpiochip
->irqdomain
);
1714 if (gpiochip
->irqchip
) {
1715 gpiochip
->irqchip
->irq_request_resources
= NULL
;
1716 gpiochip
->irqchip
->irq_release_resources
= NULL
;
1717 gpiochip
->irqchip
= NULL
;
1720 gpiochip_irqchip_free_valid_mask(gpiochip
);
1724 * _gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1725 * @gpiochip: the gpiochip to add the irqchip to
1726 * @irqchip: the irqchip to add to the gpiochip
1727 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1728 * allocate gpiochip irqs from
1729 * @handler: the irq handler to use (often a predefined irq core function)
1730 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1731 * to have the core avoid setting up any default type in the hardware.
1732 * @nested: whether this is a nested irqchip calling handle_nested_irq()
1733 * in its IRQ handler
1734 * @lock_key: lockdep class
1736 * This function closely associates a certain irqchip with a certain
1737 * gpiochip, providing an irq domain to translate the local IRQs to
1738 * global irqs in the gpiolib core, and making sure that the gpiochip
1739 * is passed as chip data to all related functions. Driver callbacks
1740 * need to use gpiochip_get_data() to get their local state containers back
1741 * from the gpiochip passed as chip data. An irqdomain will be stored
1742 * in the gpiochip that shall be used by the driver to handle IRQ number
1743 * translation. The gpiochip will need to be initialized and registered
1744 * before calling this function.
1746 * This function will handle two cell:ed simple IRQs and assumes all
1747 * the pins on the gpiochip can generate a unique IRQ. Everything else
1748 * need to be open coded.
1750 int _gpiochip_irqchip_add(struct gpio_chip
*gpiochip
,
1751 struct irq_chip
*irqchip
,
1752 unsigned int first_irq
,
1753 irq_flow_handler_t handler
,
1756 struct lock_class_key
*lock_key
)
1758 struct device_node
*of_node
;
1759 bool irq_base_set
= false;
1760 unsigned int offset
;
1761 unsigned irq_base
= 0;
1763 if (!gpiochip
|| !irqchip
)
1766 if (!gpiochip
->parent
) {
1767 pr_err("missing gpiochip .dev parent pointer\n");
1770 gpiochip
->irq_nested
= nested
;
1771 of_node
= gpiochip
->parent
->of_node
;
1772 #ifdef CONFIG_OF_GPIO
1774 * If the gpiochip has an assigned OF node this takes precedence
1775 * FIXME: get rid of this and use gpiochip->parent->of_node
1778 if (gpiochip
->of_node
)
1779 of_node
= gpiochip
->of_node
;
1782 * Specifying a default trigger is a terrible idea if DT or ACPI is
1783 * used to configure the interrupts, as you may end-up with
1784 * conflicting triggers. Tell the user, and reset to NONE.
1786 if (WARN(of_node
&& type
!= IRQ_TYPE_NONE
,
1787 "%s: Ignoring %d default trigger\n", of_node
->full_name
, type
))
1788 type
= IRQ_TYPE_NONE
;
1789 if (has_acpi_companion(gpiochip
->parent
) && type
!= IRQ_TYPE_NONE
) {
1790 acpi_handle_warn(ACPI_HANDLE(gpiochip
->parent
),
1791 "Ignoring %d default trigger\n", type
);
1792 type
= IRQ_TYPE_NONE
;
1795 gpiochip
->irqchip
= irqchip
;
1796 gpiochip
->irq_handler
= handler
;
1797 gpiochip
->irq_default_type
= type
;
1798 gpiochip
->to_irq
= gpiochip_to_irq
;
1799 gpiochip
->lock_key
= lock_key
;
1800 gpiochip
->irqdomain
= irq_domain_add_simple(of_node
,
1801 gpiochip
->ngpio
, first_irq
,
1802 &gpiochip_domain_ops
, gpiochip
);
1803 if (!gpiochip
->irqdomain
) {
1804 gpiochip
->irqchip
= NULL
;
1809 * It is possible for a driver to override this, but only if the
1810 * alternative functions are both implemented.
1812 if (!irqchip
->irq_request_resources
&&
1813 !irqchip
->irq_release_resources
) {
1814 irqchip
->irq_request_resources
= gpiochip_irq_reqres
;
1815 irqchip
->irq_release_resources
= gpiochip_irq_relres
;
1819 * Prepare the mapping since the irqchip shall be orthogonal to
1820 * any gpiochip calls. If the first_irq was zero, this is
1821 * necessary to allocate descriptors for all IRQs.
1823 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1824 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1826 irq_base
= irq_create_mapping(gpiochip
->irqdomain
, offset
);
1827 if (!irq_base_set
) {
1829 * Store the base into the gpiochip to be used when
1830 * unmapping the irqs.
1832 gpiochip
->irq_base
= irq_base
;
1833 irq_base_set
= true;
1837 acpi_gpiochip_request_interrupts(gpiochip
);
1841 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add
);
1843 #else /* CONFIG_GPIOLIB_IRQCHIP */
1845 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
) {}
1846 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
)
1850 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
)
1853 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1856 * gpiochip_generic_request() - request the gpio function for a pin
1857 * @chip: the gpiochip owning the GPIO
1858 * @offset: the offset of the GPIO to request for GPIO function
1860 int gpiochip_generic_request(struct gpio_chip
*chip
, unsigned offset
)
1862 return pinctrl_request_gpio(chip
->gpiodev
->base
+ offset
);
1864 EXPORT_SYMBOL_GPL(gpiochip_generic_request
);
1867 * gpiochip_generic_free() - free the gpio function from a pin
1868 * @chip: the gpiochip to request the gpio function for
1869 * @offset: the offset of the GPIO to free from GPIO function
1871 void gpiochip_generic_free(struct gpio_chip
*chip
, unsigned offset
)
1873 pinctrl_free_gpio(chip
->gpiodev
->base
+ offset
);
1875 EXPORT_SYMBOL_GPL(gpiochip_generic_free
);
1878 * gpiochip_generic_config() - apply configuration for a pin
1879 * @chip: the gpiochip owning the GPIO
1880 * @offset: the offset of the GPIO to apply the configuration
1881 * @config: the configuration to be applied
1883 int gpiochip_generic_config(struct gpio_chip
*chip
, unsigned offset
,
1884 unsigned long config
)
1886 return pinctrl_gpio_set_config(chip
->gpiodev
->base
+ offset
, config
);
1888 EXPORT_SYMBOL_GPL(gpiochip_generic_config
);
1890 #ifdef CONFIG_PINCTRL
1893 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1894 * @chip: the gpiochip to add the range for
1895 * @pctldev: the pin controller to map to
1896 * @gpio_offset: the start offset in the current gpio_chip number space
1897 * @pin_group: name of the pin group inside the pin controller
1899 int gpiochip_add_pingroup_range(struct gpio_chip
*chip
,
1900 struct pinctrl_dev
*pctldev
,
1901 unsigned int gpio_offset
, const char *pin_group
)
1903 struct gpio_pin_range
*pin_range
;
1904 struct gpio_device
*gdev
= chip
->gpiodev
;
1907 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1909 chip_err(chip
, "failed to allocate pin ranges\n");
1913 /* Use local offset as range ID */
1914 pin_range
->range
.id
= gpio_offset
;
1915 pin_range
->range
.gc
= chip
;
1916 pin_range
->range
.name
= chip
->label
;
1917 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1918 pin_range
->pctldev
= pctldev
;
1920 ret
= pinctrl_get_group_pins(pctldev
, pin_group
,
1921 &pin_range
->range
.pins
,
1922 &pin_range
->range
.npins
);
1928 pinctrl_add_gpio_range(pctldev
, &pin_range
->range
);
1930 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1931 gpio_offset
, gpio_offset
+ pin_range
->range
.npins
- 1,
1932 pinctrl_dev_get_devname(pctldev
), pin_group
);
1934 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1938 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range
);
1941 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1942 * @chip: the gpiochip to add the range for
1943 * @pinctrl_name: the dev_name() of the pin controller to map to
1944 * @gpio_offset: the start offset in the current gpio_chip number space
1945 * @pin_offset: the start offset in the pin controller number space
1946 * @npins: the number of pins from the offset of each pin space (GPIO and
1947 * pin controller) to accumulate in this range
1949 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
1950 unsigned int gpio_offset
, unsigned int pin_offset
,
1953 struct gpio_pin_range
*pin_range
;
1954 struct gpio_device
*gdev
= chip
->gpiodev
;
1957 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1959 chip_err(chip
, "failed to allocate pin ranges\n");
1963 /* Use local offset as range ID */
1964 pin_range
->range
.id
= gpio_offset
;
1965 pin_range
->range
.gc
= chip
;
1966 pin_range
->range
.name
= chip
->label
;
1967 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1968 pin_range
->range
.pin_base
= pin_offset
;
1969 pin_range
->range
.npins
= npins
;
1970 pin_range
->pctldev
= pinctrl_find_and_add_gpio_range(pinctl_name
,
1972 if (IS_ERR(pin_range
->pctldev
)) {
1973 ret
= PTR_ERR(pin_range
->pctldev
);
1974 chip_err(chip
, "could not create pin range\n");
1978 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1979 gpio_offset
, gpio_offset
+ npins
- 1,
1981 pin_offset
, pin_offset
+ npins
- 1);
1983 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1987 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range
);
1990 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1991 * @chip: the chip to remove all the mappings for
1993 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
1995 struct gpio_pin_range
*pin_range
, *tmp
;
1996 struct gpio_device
*gdev
= chip
->gpiodev
;
1998 list_for_each_entry_safe(pin_range
, tmp
, &gdev
->pin_ranges
, node
) {
1999 list_del(&pin_range
->node
);
2000 pinctrl_remove_gpio_range(pin_range
->pctldev
,
2005 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges
);
2007 #endif /* CONFIG_PINCTRL */
2009 /* These "optional" allocation calls help prevent drivers from stomping
2010 * on each other, and help provide better diagnostics in debugfs.
2011 * They're called even less than the "set direction" calls.
2013 static int __gpiod_request(struct gpio_desc
*desc
, const char *label
)
2015 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2017 unsigned long flags
;
2019 spin_lock_irqsave(&gpio_lock
, flags
);
2021 /* NOTE: gpio_request() can be called in early boot,
2022 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2025 if (test_and_set_bit(FLAG_REQUESTED
, &desc
->flags
) == 0) {
2026 desc_set_label(desc
, label
? : "?");
2033 if (chip
->request
) {
2034 /* chip->request may sleep */
2035 spin_unlock_irqrestore(&gpio_lock
, flags
);
2036 status
= chip
->request(chip
, gpio_chip_hwgpio(desc
));
2037 spin_lock_irqsave(&gpio_lock
, flags
);
2040 desc_set_label(desc
, NULL
);
2041 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
2045 if (chip
->get_direction
) {
2046 /* chip->get_direction may sleep */
2047 spin_unlock_irqrestore(&gpio_lock
, flags
);
2048 gpiod_get_direction(desc
);
2049 spin_lock_irqsave(&gpio_lock
, flags
);
2052 spin_unlock_irqrestore(&gpio_lock
, flags
);
2057 * This descriptor validation needs to be inserted verbatim into each
2058 * function taking a descriptor, so we need to use a preprocessor
2059 * macro to avoid endless duplication. If the desc is NULL it is an
2060 * optional GPIO and calls should just bail out.
2062 #define VALIDATE_DESC(desc) do { \
2065 if (IS_ERR(desc)) { \
2066 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2067 return PTR_ERR(desc); \
2069 if (!desc->gdev) { \
2070 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2073 if ( !desc->gdev->chip ) { \
2074 dev_warn(&desc->gdev->dev, \
2075 "%s: backing chip is gone\n", __func__); \
2079 #define VALIDATE_DESC_VOID(desc) do { \
2082 if (IS_ERR(desc)) { \
2083 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2086 if (!desc->gdev) { \
2087 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2090 if (!desc->gdev->chip) { \
2091 dev_warn(&desc->gdev->dev, \
2092 "%s: backing chip is gone\n", __func__); \
2097 int gpiod_request(struct gpio_desc
*desc
, const char *label
)
2099 int status
= -EPROBE_DEFER
;
2100 struct gpio_device
*gdev
;
2102 VALIDATE_DESC(desc
);
2105 if (try_module_get(gdev
->owner
)) {
2106 status
= __gpiod_request(desc
, label
);
2108 module_put(gdev
->owner
);
2110 get_device(&gdev
->dev
);
2114 gpiod_dbg(desc
, "%s: status %d\n", __func__
, status
);
2119 static bool __gpiod_free(struct gpio_desc
*desc
)
2122 unsigned long flags
;
2123 struct gpio_chip
*chip
;
2127 gpiod_unexport(desc
);
2129 spin_lock_irqsave(&gpio_lock
, flags
);
2131 chip
= desc
->gdev
->chip
;
2132 if (chip
&& test_bit(FLAG_REQUESTED
, &desc
->flags
)) {
2134 spin_unlock_irqrestore(&gpio_lock
, flags
);
2135 might_sleep_if(chip
->can_sleep
);
2136 chip
->free(chip
, gpio_chip_hwgpio(desc
));
2137 spin_lock_irqsave(&gpio_lock
, flags
);
2139 desc_set_label(desc
, NULL
);
2140 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2141 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
2142 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2143 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2144 clear_bit(FLAG_IS_HOGGED
, &desc
->flags
);
2148 spin_unlock_irqrestore(&gpio_lock
, flags
);
2152 void gpiod_free(struct gpio_desc
*desc
)
2154 if (desc
&& desc
->gdev
&& __gpiod_free(desc
)) {
2155 module_put(desc
->gdev
->owner
);
2156 put_device(&desc
->gdev
->dev
);
2158 WARN_ON(extra_checks
);
2163 * gpiochip_is_requested - return string iff signal was requested
2164 * @chip: controller managing the signal
2165 * @offset: of signal within controller's 0..(ngpio - 1) range
2167 * Returns NULL if the GPIO is not currently requested, else a string.
2168 * The string returned is the label passed to gpio_request(); if none has been
2169 * passed it is a meaningless, non-NULL constant.
2171 * This function is for use by GPIO controller drivers. The label can
2172 * help with diagnostics, and knowing that the signal is used as a GPIO
2173 * can help avoid accidentally multiplexing it to another controller.
2175 const char *gpiochip_is_requested(struct gpio_chip
*chip
, unsigned offset
)
2177 struct gpio_desc
*desc
;
2179 if (offset
>= chip
->ngpio
)
2182 desc
= &chip
->gpiodev
->descs
[offset
];
2184 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) == 0)
2188 EXPORT_SYMBOL_GPL(gpiochip_is_requested
);
2191 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2192 * @desc: GPIO descriptor to request
2193 * @label: label for the GPIO
2195 * Function allows GPIO chip drivers to request and use their own GPIO
2196 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2197 * function will not increase reference count of the GPIO chip module. This
2198 * allows the GPIO chip module to be unloaded as needed (we assume that the
2199 * GPIO chip driver handles freeing the GPIOs it has requested).
2201 struct gpio_desc
*gpiochip_request_own_desc(struct gpio_chip
*chip
, u16 hwnum
,
2204 struct gpio_desc
*desc
= gpiochip_get_desc(chip
, hwnum
);
2208 chip_err(chip
, "failed to get GPIO descriptor\n");
2212 err
= __gpiod_request(desc
, label
);
2214 return ERR_PTR(err
);
2218 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc
);
2221 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2222 * @desc: GPIO descriptor to free
2224 * Function frees the given GPIO requested previously with
2225 * gpiochip_request_own_desc().
2227 void gpiochip_free_own_desc(struct gpio_desc
*desc
)
2232 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc
);
2235 * Drivers MUST set GPIO direction before making get/set calls. In
2236 * some cases this is done in early boot, before IRQs are enabled.
2238 * As a rule these aren't called more than once (except for drivers
2239 * using the open-drain emulation idiom) so these are natural places
2240 * to accumulate extra debugging checks. Note that we can't (yet)
2241 * rely on gpio_request() having been called beforehand.
2245 * gpiod_direction_input - set the GPIO direction to input
2246 * @desc: GPIO to set to input
2248 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2249 * be called safely on it.
2251 * Return 0 in case of success, else an error code.
2253 int gpiod_direction_input(struct gpio_desc
*desc
)
2255 struct gpio_chip
*chip
;
2256 int status
= -EINVAL
;
2258 VALIDATE_DESC(desc
);
2259 chip
= desc
->gdev
->chip
;
2261 if (!chip
->get
|| !chip
->direction_input
) {
2263 "%s: missing get() or direction_input() operations\n",
2268 status
= chip
->direction_input(chip
, gpio_chip_hwgpio(desc
));
2270 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2272 trace_gpio_direction(desc_to_gpio(desc
), 1, status
);
2276 EXPORT_SYMBOL_GPL(gpiod_direction_input
);
2278 static int gpio_set_drive_single_ended(struct gpio_chip
*gc
, unsigned offset
,
2279 enum pin_config_param mode
)
2281 unsigned long config
= { PIN_CONF_PACKED(mode
, 0) };
2283 return gc
->set_config
? gc
->set_config(gc
, offset
, config
) : -ENOTSUPP
;
2286 static int _gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
2288 struct gpio_chip
*gc
= desc
->gdev
->chip
;
2292 /* GPIOs used for IRQs shall not be set as output */
2293 if (test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
)) {
2295 "%s: tried to set a GPIO tied to an IRQ as output\n",
2300 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
2301 /* First see if we can enable open drain in hardware */
2302 ret
= gpio_set_drive_single_ended(gc
, gpio_chip_hwgpio(desc
),
2303 PIN_CONFIG_DRIVE_OPEN_DRAIN
);
2305 goto set_output_value
;
2306 /* Emulate open drain by not actively driving the line high */
2308 return gpiod_direction_input(desc
);
2310 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
2311 ret
= gpio_set_drive_single_ended(gc
, gpio_chip_hwgpio(desc
),
2312 PIN_CONFIG_DRIVE_OPEN_SOURCE
);
2314 goto set_output_value
;
2315 /* Emulate open source by not actively driving the line low */
2317 return gpiod_direction_input(desc
);
2319 gpio_set_drive_single_ended(gc
, gpio_chip_hwgpio(desc
),
2320 PIN_CONFIG_DRIVE_PUSH_PULL
);
2324 if (!gc
->set
|| !gc
->direction_output
) {
2326 "%s: missing set() or direction_output() operations\n",
2331 ret
= gc
->direction_output(gc
, gpio_chip_hwgpio(desc
), val
);
2333 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2334 trace_gpio_value(desc_to_gpio(desc
), 0, val
);
2335 trace_gpio_direction(desc_to_gpio(desc
), 0, ret
);
2340 * gpiod_direction_output_raw - set the GPIO direction to output
2341 * @desc: GPIO to set to output
2342 * @value: initial output value of the GPIO
2344 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2345 * be called safely on it. The initial value of the output must be specified
2346 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2348 * Return 0 in case of success, else an error code.
2350 int gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
2352 VALIDATE_DESC(desc
);
2353 return _gpiod_direction_output_raw(desc
, value
);
2355 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw
);
2358 * gpiod_direction_output - set the GPIO direction to output
2359 * @desc: GPIO to set to output
2360 * @value: initial output value of the GPIO
2362 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2363 * be called safely on it. The initial value of the output must be specified
2364 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2367 * Return 0 in case of success, else an error code.
2369 int gpiod_direction_output(struct gpio_desc
*desc
, int value
)
2371 VALIDATE_DESC(desc
);
2372 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2376 return _gpiod_direction_output_raw(desc
, value
);
2378 EXPORT_SYMBOL_GPL(gpiod_direction_output
);
2381 * gpiod_set_debounce - sets @debounce time for a @gpio
2382 * @gpio: the gpio to set debounce time
2383 * @debounce: debounce time is microseconds
2385 * returns -ENOTSUPP if the controller does not support setting
2388 int gpiod_set_debounce(struct gpio_desc
*desc
, unsigned debounce
)
2390 struct gpio_chip
*chip
;
2391 unsigned long config
;
2393 VALIDATE_DESC(desc
);
2394 chip
= desc
->gdev
->chip
;
2395 if (!chip
->set
|| !chip
->set_config
) {
2397 "%s: missing set() or set_config() operations\n",
2402 config
= pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE
, debounce
);
2403 return chip
->set_config(chip
, gpio_chip_hwgpio(desc
), config
);
2405 EXPORT_SYMBOL_GPL(gpiod_set_debounce
);
2408 * gpiod_is_active_low - test whether a GPIO is active-low or not
2409 * @desc: the gpio descriptor to test
2411 * Returns 1 if the GPIO is active-low, 0 otherwise.
2413 int gpiod_is_active_low(const struct gpio_desc
*desc
)
2415 VALIDATE_DESC(desc
);
2416 return test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2418 EXPORT_SYMBOL_GPL(gpiod_is_active_low
);
2420 /* I/O calls are only valid after configuration completed; the relevant
2421 * "is this a valid GPIO" error checks should already have been done.
2423 * "Get" operations are often inlinable as reading a pin value register,
2424 * and masking the relevant bit in that register.
2426 * When "set" operations are inlinable, they involve writing that mask to
2427 * one register to set a low value, or a different register to set it high.
2428 * Otherwise locking is needed, so there may be little value to inlining.
2430 *------------------------------------------------------------------------
2432 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2433 * have requested the GPIO. That can include implicit requesting by
2434 * a direction setting call. Marking a gpio as requested locks its chip
2435 * in memory, guaranteeing that these table lookups need no more locking
2436 * and that gpiochip_remove() will fail.
2438 * REVISIT when debugging, consider adding some instrumentation to ensure
2439 * that the GPIO was actually requested.
2442 static int _gpiod_get_raw_value(const struct gpio_desc
*desc
)
2444 struct gpio_chip
*chip
;
2448 chip
= desc
->gdev
->chip
;
2449 offset
= gpio_chip_hwgpio(desc
);
2450 value
= chip
->get
? chip
->get(chip
, offset
) : -EIO
;
2451 value
= value
< 0 ? value
: !!value
;
2452 trace_gpio_value(desc_to_gpio(desc
), 1, value
);
2457 * gpiod_get_raw_value() - return a gpio's raw value
2458 * @desc: gpio whose value will be returned
2460 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2461 * its ACTIVE_LOW status, or negative errno on failure.
2463 * This function should be called from contexts where we cannot sleep, and will
2464 * complain if the GPIO chip functions potentially sleep.
2466 int gpiod_get_raw_value(const struct gpio_desc
*desc
)
2468 VALIDATE_DESC(desc
);
2469 /* Should be using gpio_get_value_cansleep() */
2470 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2471 return _gpiod_get_raw_value(desc
);
2473 EXPORT_SYMBOL_GPL(gpiod_get_raw_value
);
2476 * gpiod_get_value() - return a gpio's value
2477 * @desc: gpio whose value will be returned
2479 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2480 * account, or negative errno on failure.
2482 * This function should be called from contexts where we cannot sleep, and will
2483 * complain if the GPIO chip functions potentially sleep.
2485 int gpiod_get_value(const struct gpio_desc
*desc
)
2489 VALIDATE_DESC(desc
);
2490 /* Should be using gpio_get_value_cansleep() */
2491 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2493 value
= _gpiod_get_raw_value(desc
);
2497 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2502 EXPORT_SYMBOL_GPL(gpiod_get_value
);
2505 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2506 * @desc: gpio descriptor whose state need to be set.
2507 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2509 static void _gpio_set_open_drain_value(struct gpio_desc
*desc
, bool value
)
2512 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2513 int offset
= gpio_chip_hwgpio(desc
);
2516 err
= chip
->direction_input(chip
, offset
);
2518 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2520 err
= chip
->direction_output(chip
, offset
, 0);
2522 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2524 trace_gpio_direction(desc_to_gpio(desc
), value
, err
);
2527 "%s: Error in set_value for open drain err %d\n",
2532 * _gpio_set_open_source_value() - Set the open source gpio's value.
2533 * @desc: gpio descriptor whose state need to be set.
2534 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2536 static void _gpio_set_open_source_value(struct gpio_desc
*desc
, bool value
)
2539 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2540 int offset
= gpio_chip_hwgpio(desc
);
2543 err
= chip
->direction_output(chip
, offset
, 1);
2545 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2547 err
= chip
->direction_input(chip
, offset
);
2549 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2551 trace_gpio_direction(desc_to_gpio(desc
), !value
, err
);
2554 "%s: Error in set_value for open source err %d\n",
2558 static void _gpiod_set_raw_value(struct gpio_desc
*desc
, bool value
)
2560 struct gpio_chip
*chip
;
2562 chip
= desc
->gdev
->chip
;
2563 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
2564 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
2565 _gpio_set_open_drain_value(desc
, value
);
2566 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
2567 _gpio_set_open_source_value(desc
, value
);
2569 chip
->set(chip
, gpio_chip_hwgpio(desc
), value
);
2573 * set multiple outputs on the same chip;
2574 * use the chip's set_multiple function if available;
2575 * otherwise set the outputs sequentially;
2576 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2577 * defines which outputs are to be changed
2578 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2579 * defines the values the outputs specified by mask are to be set to
2581 static void gpio_chip_set_multiple(struct gpio_chip
*chip
,
2582 unsigned long *mask
, unsigned long *bits
)
2584 if (chip
->set_multiple
) {
2585 chip
->set_multiple(chip
, mask
, bits
);
2589 /* set outputs if the corresponding mask bit is set */
2590 for_each_set_bit(i
, mask
, chip
->ngpio
)
2591 chip
->set(chip
, i
, test_bit(i
, bits
));
2595 void gpiod_set_array_value_complex(bool raw
, bool can_sleep
,
2596 unsigned int array_size
,
2597 struct gpio_desc
**desc_array
,
2602 while (i
< array_size
) {
2603 struct gpio_chip
*chip
= desc_array
[i
]->gdev
->chip
;
2604 unsigned long mask
[BITS_TO_LONGS(chip
->ngpio
)];
2605 unsigned long bits
[BITS_TO_LONGS(chip
->ngpio
)];
2609 WARN_ON(chip
->can_sleep
);
2611 memset(mask
, 0, sizeof(mask
));
2613 struct gpio_desc
*desc
= desc_array
[i
];
2614 int hwgpio
= gpio_chip_hwgpio(desc
);
2615 int value
= value_array
[i
];
2617 if (!raw
&& test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2619 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
2621 * collect all normal outputs belonging to the same chip
2622 * open drain and open source outputs are set individually
2624 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
2625 _gpio_set_open_drain_value(desc
, value
);
2626 } else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
2627 _gpio_set_open_source_value(desc
, value
);
2629 __set_bit(hwgpio
, mask
);
2631 __set_bit(hwgpio
, bits
);
2633 __clear_bit(hwgpio
, bits
);
2637 } while ((i
< array_size
) &&
2638 (desc_array
[i
]->gdev
->chip
== chip
));
2639 /* push collected bits to outputs */
2641 gpio_chip_set_multiple(chip
, mask
, bits
);
2646 * gpiod_set_raw_value() - assign a gpio's raw value
2647 * @desc: gpio whose value will be assigned
2648 * @value: value to assign
2650 * Set the raw value of the GPIO, i.e. the value of its physical line without
2651 * regard for its ACTIVE_LOW status.
2653 * This function should be called from contexts where we cannot sleep, and will
2654 * complain if the GPIO chip functions potentially sleep.
2656 void gpiod_set_raw_value(struct gpio_desc
*desc
, int value
)
2658 VALIDATE_DESC_VOID(desc
);
2659 /* Should be using gpiod_set_value_cansleep() */
2660 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2661 _gpiod_set_raw_value(desc
, value
);
2663 EXPORT_SYMBOL_GPL(gpiod_set_raw_value
);
2666 * gpiod_set_value() - assign a gpio's value
2667 * @desc: gpio whose value will be assigned
2668 * @value: value to assign
2670 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2673 * This function should be called from contexts where we cannot sleep, and will
2674 * complain if the GPIO chip functions potentially sleep.
2676 void gpiod_set_value(struct gpio_desc
*desc
, int value
)
2678 VALIDATE_DESC_VOID(desc
);
2679 /* Should be using gpiod_set_value_cansleep() */
2680 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2681 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2683 _gpiod_set_raw_value(desc
, value
);
2685 EXPORT_SYMBOL_GPL(gpiod_set_value
);
2688 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2689 * @array_size: number of elements in the descriptor / value arrays
2690 * @desc_array: array of GPIO descriptors whose values will be assigned
2691 * @value_array: array of values to assign
2693 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2694 * without regard for their ACTIVE_LOW status.
2696 * This function should be called from contexts where we cannot sleep, and will
2697 * complain if the GPIO chip functions potentially sleep.
2699 void gpiod_set_raw_array_value(unsigned int array_size
,
2700 struct gpio_desc
**desc_array
, int *value_array
)
2704 gpiod_set_array_value_complex(true, false, array_size
, desc_array
,
2707 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value
);
2710 * gpiod_set_array_value() - assign values to an array of GPIOs
2711 * @array_size: number of elements in the descriptor / value arrays
2712 * @desc_array: array of GPIO descriptors whose values will be assigned
2713 * @value_array: array of values to assign
2715 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2718 * This function should be called from contexts where we cannot sleep, and will
2719 * complain if the GPIO chip functions potentially sleep.
2721 void gpiod_set_array_value(unsigned int array_size
,
2722 struct gpio_desc
**desc_array
, int *value_array
)
2726 gpiod_set_array_value_complex(false, false, array_size
, desc_array
,
2729 EXPORT_SYMBOL_GPL(gpiod_set_array_value
);
2732 * gpiod_cansleep() - report whether gpio value access may sleep
2733 * @desc: gpio to check
2736 int gpiod_cansleep(const struct gpio_desc
*desc
)
2738 VALIDATE_DESC(desc
);
2739 return desc
->gdev
->chip
->can_sleep
;
2741 EXPORT_SYMBOL_GPL(gpiod_cansleep
);
2744 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2745 * @desc: gpio whose IRQ will be returned (already requested)
2747 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2750 int gpiod_to_irq(const struct gpio_desc
*desc
)
2752 struct gpio_chip
*chip
;
2756 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2757 * requires this function to not return zero on an invalid descriptor
2758 * but rather a negative error number.
2760 if (!desc
|| IS_ERR(desc
) || !desc
->gdev
|| !desc
->gdev
->chip
)
2763 chip
= desc
->gdev
->chip
;
2764 offset
= gpio_chip_hwgpio(desc
);
2766 int retirq
= chip
->to_irq(chip
, offset
);
2768 /* Zero means NO_IRQ */
2776 EXPORT_SYMBOL_GPL(gpiod_to_irq
);
2779 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2780 * @chip: the chip the GPIO to lock belongs to
2781 * @offset: the offset of the GPIO to lock as IRQ
2783 * This is used directly by GPIO drivers that want to lock down
2784 * a certain GPIO line to be used for IRQs.
2786 int gpiochip_lock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2788 struct gpio_desc
*desc
;
2790 desc
= gpiochip_get_desc(chip
, offset
);
2792 return PTR_ERR(desc
);
2795 * If it's fast: flush the direction setting if something changed
2798 if (!chip
->can_sleep
&& chip
->get_direction
) {
2799 int dir
= chip
->get_direction(chip
, offset
);
2802 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2804 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2807 if (test_bit(FLAG_IS_OUT
, &desc
->flags
)) {
2809 "%s: tried to flag a GPIO set as output for IRQ\n",
2814 set_bit(FLAG_USED_AS_IRQ
, &desc
->flags
);
2817 * If the consumer has not set up a label (such as when the
2818 * IRQ is referenced from .to_irq()) we set up a label here
2819 * so it is clear this is used as an interrupt.
2822 desc_set_label(desc
, "interrupt");
2826 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq
);
2829 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2830 * @chip: the chip the GPIO to lock belongs to
2831 * @offset: the offset of the GPIO to lock as IRQ
2833 * This is used directly by GPIO drivers that want to indicate
2834 * that a certain GPIO is no longer used exclusively for IRQ.
2836 void gpiochip_unlock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2838 struct gpio_desc
*desc
;
2840 desc
= gpiochip_get_desc(chip
, offset
);
2844 clear_bit(FLAG_USED_AS_IRQ
, &desc
->flags
);
2846 /* If we only had this marking, erase it */
2847 if (desc
->label
&& !strcmp(desc
->label
, "interrupt"))
2848 desc_set_label(desc
, NULL
);
2850 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq
);
2852 bool gpiochip_line_is_irq(struct gpio_chip
*chip
, unsigned int offset
)
2854 if (offset
>= chip
->ngpio
)
2857 return test_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2859 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq
);
2861 bool gpiochip_line_is_open_drain(struct gpio_chip
*chip
, unsigned int offset
)
2863 if (offset
>= chip
->ngpio
)
2866 return test_bit(FLAG_OPEN_DRAIN
, &chip
->gpiodev
->descs
[offset
].flags
);
2868 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain
);
2870 bool gpiochip_line_is_open_source(struct gpio_chip
*chip
, unsigned int offset
)
2872 if (offset
>= chip
->ngpio
)
2875 return test_bit(FLAG_OPEN_SOURCE
, &chip
->gpiodev
->descs
[offset
].flags
);
2877 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source
);
2880 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2881 * @desc: gpio whose value will be returned
2883 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2884 * its ACTIVE_LOW status, or negative errno on failure.
2886 * This function is to be called from contexts that can sleep.
2888 int gpiod_get_raw_value_cansleep(const struct gpio_desc
*desc
)
2890 might_sleep_if(extra_checks
);
2891 VALIDATE_DESC(desc
);
2892 return _gpiod_get_raw_value(desc
);
2894 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep
);
2897 * gpiod_get_value_cansleep() - return a gpio's value
2898 * @desc: gpio whose value will be returned
2900 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2901 * account, or negative errno on failure.
2903 * This function is to be called from contexts that can sleep.
2905 int gpiod_get_value_cansleep(const struct gpio_desc
*desc
)
2909 might_sleep_if(extra_checks
);
2910 VALIDATE_DESC(desc
);
2911 value
= _gpiod_get_raw_value(desc
);
2915 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2920 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep
);
2923 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2924 * @desc: gpio whose value will be assigned
2925 * @value: value to assign
2927 * Set the raw value of the GPIO, i.e. the value of its physical line without
2928 * regard for its ACTIVE_LOW status.
2930 * This function is to be called from contexts that can sleep.
2932 void gpiod_set_raw_value_cansleep(struct gpio_desc
*desc
, int value
)
2934 might_sleep_if(extra_checks
);
2935 VALIDATE_DESC_VOID(desc
);
2936 _gpiod_set_raw_value(desc
, value
);
2938 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep
);
2941 * gpiod_set_value_cansleep() - assign a gpio's value
2942 * @desc: gpio whose value will be assigned
2943 * @value: value to assign
2945 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2948 * This function is to be called from contexts that can sleep.
2950 void gpiod_set_value_cansleep(struct gpio_desc
*desc
, int value
)
2952 might_sleep_if(extra_checks
);
2953 VALIDATE_DESC_VOID(desc
);
2954 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2956 _gpiod_set_raw_value(desc
, value
);
2958 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep
);
2961 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2962 * @array_size: number of elements in the descriptor / value arrays
2963 * @desc_array: array of GPIO descriptors whose values will be assigned
2964 * @value_array: array of values to assign
2966 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2967 * without regard for their ACTIVE_LOW status.
2969 * This function is to be called from contexts that can sleep.
2971 void gpiod_set_raw_array_value_cansleep(unsigned int array_size
,
2972 struct gpio_desc
**desc_array
,
2975 might_sleep_if(extra_checks
);
2978 gpiod_set_array_value_complex(true, true, array_size
, desc_array
,
2981 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep
);
2984 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2985 * @array_size: number of elements in the descriptor / value arrays
2986 * @desc_array: array of GPIO descriptors whose values will be assigned
2987 * @value_array: array of values to assign
2989 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2992 * This function is to be called from contexts that can sleep.
2994 void gpiod_set_array_value_cansleep(unsigned int array_size
,
2995 struct gpio_desc
**desc_array
,
2998 might_sleep_if(extra_checks
);
3001 gpiod_set_array_value_complex(false, true, array_size
, desc_array
,
3004 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep
);
3007 * gpiod_add_lookup_table() - register GPIO device consumers
3008 * @table: table of consumers to register
3010 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
)
3012 mutex_lock(&gpio_lookup_lock
);
3014 list_add_tail(&table
->list
, &gpio_lookup_list
);
3016 mutex_unlock(&gpio_lookup_lock
);
3020 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3021 * @table: table of consumers to unregister
3023 void gpiod_remove_lookup_table(struct gpiod_lookup_table
*table
)
3025 mutex_lock(&gpio_lookup_lock
);
3027 list_del(&table
->list
);
3029 mutex_unlock(&gpio_lookup_lock
);
3032 static struct gpiod_lookup_table
*gpiod_find_lookup_table(struct device
*dev
)
3034 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
3035 struct gpiod_lookup_table
*table
;
3037 mutex_lock(&gpio_lookup_lock
);
3039 list_for_each_entry(table
, &gpio_lookup_list
, list
) {
3040 if (table
->dev_id
&& dev_id
) {
3042 * Valid strings on both ends, must be identical to have
3045 if (!strcmp(table
->dev_id
, dev_id
))
3049 * One of the pointers is NULL, so both must be to have
3052 if (dev_id
== table
->dev_id
)
3059 mutex_unlock(&gpio_lookup_lock
);
3063 static struct gpio_desc
*gpiod_find(struct device
*dev
, const char *con_id
,
3065 enum gpio_lookup_flags
*flags
)
3067 struct gpio_desc
*desc
= ERR_PTR(-ENOENT
);
3068 struct gpiod_lookup_table
*table
;
3069 struct gpiod_lookup
*p
;
3071 table
= gpiod_find_lookup_table(dev
);
3075 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
3076 struct gpio_chip
*chip
;
3078 /* idx must always match exactly */
3082 /* If the lookup entry has a con_id, require exact match */
3083 if (p
->con_id
&& (!con_id
|| strcmp(p
->con_id
, con_id
)))
3086 chip
= find_chip_by_name(p
->chip_label
);
3089 dev_err(dev
, "cannot find GPIO chip %s\n",
3091 return ERR_PTR(-ENODEV
);
3094 if (chip
->ngpio
<= p
->chip_hwnum
) {
3096 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3097 idx
, chip
->ngpio
, chip
->label
);
3098 return ERR_PTR(-EINVAL
);
3101 desc
= gpiochip_get_desc(chip
, p
->chip_hwnum
);
3110 static int dt_gpio_count(struct device
*dev
, const char *con_id
)
3116 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
3118 snprintf(propname
, sizeof(propname
), "%s-%s",
3119 con_id
, gpio_suffixes
[i
]);
3121 snprintf(propname
, sizeof(propname
), "%s",
3124 ret
= of_gpio_named_count(dev
->of_node
, propname
);
3131 static int platform_gpio_count(struct device
*dev
, const char *con_id
)
3133 struct gpiod_lookup_table
*table
;
3134 struct gpiod_lookup
*p
;
3135 unsigned int count
= 0;
3137 table
= gpiod_find_lookup_table(dev
);
3141 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
3142 if ((con_id
&& p
->con_id
&& !strcmp(con_id
, p
->con_id
)) ||
3143 (!con_id
&& !p
->con_id
))
3153 * gpiod_count - return the number of GPIOs associated with a device / function
3154 * or -ENOENT if no GPIO has been assigned to the requested function
3155 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3156 * @con_id: function within the GPIO consumer
3158 int gpiod_count(struct device
*dev
, const char *con_id
)
3160 int count
= -ENOENT
;
3162 if (IS_ENABLED(CONFIG_OF
) && dev
&& dev
->of_node
)
3163 count
= dt_gpio_count(dev
, con_id
);
3164 else if (IS_ENABLED(CONFIG_ACPI
) && dev
&& ACPI_HANDLE(dev
))
3165 count
= acpi_gpio_count(dev
, con_id
);
3168 count
= platform_gpio_count(dev
, con_id
);
3172 EXPORT_SYMBOL_GPL(gpiod_count
);
3175 * gpiod_get - obtain a GPIO for a given GPIO function
3176 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3177 * @con_id: function within the GPIO consumer
3178 * @flags: optional GPIO initialization flags
3180 * Return the GPIO descriptor corresponding to the function con_id of device
3181 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3182 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3184 struct gpio_desc
*__must_check
gpiod_get(struct device
*dev
, const char *con_id
,
3185 enum gpiod_flags flags
)
3187 return gpiod_get_index(dev
, con_id
, 0, flags
);
3189 EXPORT_SYMBOL_GPL(gpiod_get
);
3192 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3193 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3194 * @con_id: function within the GPIO consumer
3195 * @flags: optional GPIO initialization flags
3197 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3198 * the requested function it will return NULL. This is convenient for drivers
3199 * that need to handle optional GPIOs.
3201 struct gpio_desc
*__must_check
gpiod_get_optional(struct device
*dev
,
3203 enum gpiod_flags flags
)
3205 return gpiod_get_index_optional(dev
, con_id
, 0, flags
);
3207 EXPORT_SYMBOL_GPL(gpiod_get_optional
);
3211 * gpiod_configure_flags - helper function to configure a given GPIO
3212 * @desc: gpio whose value will be assigned
3213 * @con_id: function within the GPIO consumer
3214 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3216 * @dflags: gpiod_flags - optional GPIO initialization flags
3218 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3219 * requested function and/or index, or another IS_ERR() code if an error
3220 * occurred while trying to acquire the GPIO.
3222 static int gpiod_configure_flags(struct gpio_desc
*desc
, const char *con_id
,
3223 unsigned long lflags
, enum gpiod_flags dflags
)
3227 if (lflags
& GPIO_ACTIVE_LOW
)
3228 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
3229 if (lflags
& GPIO_OPEN_DRAIN
)
3230 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
3231 if (lflags
& GPIO_OPEN_SOURCE
)
3232 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
3234 /* No particular flag request, return here... */
3235 if (!(dflags
& GPIOD_FLAGS_BIT_DIR_SET
)) {
3236 pr_debug("no flags found for %s\n", con_id
);
3241 if (dflags
& GPIOD_FLAGS_BIT_DIR_OUT
)
3242 status
= gpiod_direction_output(desc
,
3243 !!(dflags
& GPIOD_FLAGS_BIT_DIR_VAL
));
3245 status
= gpiod_direction_input(desc
);
3251 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3252 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3253 * @con_id: function within the GPIO consumer
3254 * @idx: index of the GPIO to obtain in the consumer
3255 * @flags: optional GPIO initialization flags
3257 * This variant of gpiod_get() allows to access GPIOs other than the first
3258 * defined one for functions that define several GPIOs.
3260 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3261 * requested function and/or index, or another IS_ERR() code if an error
3262 * occurred while trying to acquire the GPIO.
3264 struct gpio_desc
*__must_check
gpiod_get_index(struct device
*dev
,
3267 enum gpiod_flags flags
)
3269 struct gpio_desc
*desc
= NULL
;
3271 enum gpio_lookup_flags lookupflags
= 0;
3273 dev_dbg(dev
, "GPIO lookup for consumer %s\n", con_id
);
3276 /* Using device tree? */
3277 if (IS_ENABLED(CONFIG_OF
) && dev
->of_node
) {
3278 dev_dbg(dev
, "using device tree for GPIO lookup\n");
3279 desc
= of_find_gpio(dev
, con_id
, idx
, &lookupflags
);
3280 } else if (ACPI_COMPANION(dev
)) {
3281 dev_dbg(dev
, "using ACPI for GPIO lookup\n");
3282 desc
= acpi_find_gpio(dev
, con_id
, idx
, flags
, &lookupflags
);
3287 * Either we are not using DT or ACPI, or their lookup did not return
3288 * a result. In that case, use platform lookup as a fallback.
3290 if (!desc
|| desc
== ERR_PTR(-ENOENT
)) {
3291 dev_dbg(dev
, "using lookup tables for GPIO lookup\n");
3292 desc
= gpiod_find(dev
, con_id
, idx
, &lookupflags
);
3296 dev_dbg(dev
, "lookup for GPIO %s failed\n", con_id
);
3300 status
= gpiod_request(desc
, con_id
);
3302 return ERR_PTR(status
);
3304 status
= gpiod_configure_flags(desc
, con_id
, lookupflags
, flags
);
3306 dev_dbg(dev
, "setup of GPIO %s failed\n", con_id
);
3308 return ERR_PTR(status
);
3313 EXPORT_SYMBOL_GPL(gpiod_get_index
);
3316 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3317 * @fwnode: handle of the firmware node
3318 * @propname: name of the firmware property representing the GPIO
3319 * @dflags: GPIO initialization flags
3321 * This function can be used for drivers that get their configuration
3324 * Function properly finds the corresponding GPIO using whatever is the
3325 * underlying firmware interface and then makes sure that the GPIO
3326 * descriptor is requested before it is returned to the caller.
3328 * On successfull request the GPIO pin is configured in accordance with
3331 * In case of error an ERR_PTR() is returned.
3333 struct gpio_desc
*fwnode_get_named_gpiod(struct fwnode_handle
*fwnode
,
3334 const char *propname
,
3335 enum gpiod_flags dflags
,
3338 struct gpio_desc
*desc
= ERR_PTR(-ENODEV
);
3339 unsigned long lflags
= 0;
3340 bool active_low
= false;
3341 bool single_ended
= false;
3345 return ERR_PTR(-EINVAL
);
3347 if (is_of_node(fwnode
)) {
3348 enum of_gpio_flags flags
;
3350 desc
= of_get_named_gpiod_flags(to_of_node(fwnode
), propname
, 0,
3352 if (!IS_ERR(desc
)) {
3353 active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
3354 single_ended
= flags
& OF_GPIO_SINGLE_ENDED
;
3356 } else if (is_acpi_node(fwnode
)) {
3357 struct acpi_gpio_info info
;
3359 desc
= acpi_node_get_gpiod(fwnode
, propname
, 0, &info
);
3361 active_low
= info
.polarity
== GPIO_ACTIVE_LOW
;
3367 ret
= gpiod_request(desc
, label
);
3369 return ERR_PTR(ret
);
3372 lflags
|= GPIO_ACTIVE_LOW
;
3376 lflags
|= GPIO_OPEN_DRAIN
;
3378 lflags
|= GPIO_OPEN_SOURCE
;
3381 ret
= gpiod_configure_flags(desc
, propname
, lflags
, dflags
);
3384 return ERR_PTR(ret
);
3389 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod
);
3392 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3394 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3395 * @con_id: function within the GPIO consumer
3396 * @index: index of the GPIO to obtain in the consumer
3397 * @flags: optional GPIO initialization flags
3399 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3400 * specified index was assigned to the requested function it will return NULL.
3401 * This is convenient for drivers that need to handle optional GPIOs.
3403 struct gpio_desc
*__must_check
gpiod_get_index_optional(struct device
*dev
,
3406 enum gpiod_flags flags
)
3408 struct gpio_desc
*desc
;
3410 desc
= gpiod_get_index(dev
, con_id
, index
, flags
);
3412 if (PTR_ERR(desc
) == -ENOENT
)
3418 EXPORT_SYMBOL_GPL(gpiod_get_index_optional
);
3421 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3422 * @desc: gpio whose value will be assigned
3423 * @name: gpio line name
3424 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3426 * @dflags: gpiod_flags - optional GPIO initialization flags
3428 int gpiod_hog(struct gpio_desc
*desc
, const char *name
,
3429 unsigned long lflags
, enum gpiod_flags dflags
)
3431 struct gpio_chip
*chip
;
3432 struct gpio_desc
*local_desc
;
3436 chip
= gpiod_to_chip(desc
);
3437 hwnum
= gpio_chip_hwgpio(desc
);
3439 local_desc
= gpiochip_request_own_desc(chip
, hwnum
, name
);
3440 if (IS_ERR(local_desc
)) {
3441 status
= PTR_ERR(local_desc
);
3442 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3443 name
, chip
->label
, hwnum
, status
);
3447 status
= gpiod_configure_flags(desc
, name
, lflags
, dflags
);
3449 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3450 name
, chip
->label
, hwnum
, status
);
3451 gpiochip_free_own_desc(desc
);
3455 /* Mark GPIO as hogged so it can be identified and removed later */
3456 set_bit(FLAG_IS_HOGGED
, &desc
->flags
);
3458 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3459 desc_to_gpio(desc
), name
,
3460 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ? "output" : "input",
3461 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ?
3462 (dflags
&GPIOD_FLAGS_BIT_DIR_VAL
) ? "/high" : "/low":"");
3468 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3469 * @chip: gpio chip to act on
3471 * This is only used by of_gpiochip_remove to free hogged gpios
3473 static void gpiochip_free_hogs(struct gpio_chip
*chip
)
3477 for (id
= 0; id
< chip
->ngpio
; id
++) {
3478 if (test_bit(FLAG_IS_HOGGED
, &chip
->gpiodev
->descs
[id
].flags
))
3479 gpiochip_free_own_desc(&chip
->gpiodev
->descs
[id
]);
3484 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3485 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3486 * @con_id: function within the GPIO consumer
3487 * @flags: optional GPIO initialization flags
3489 * This function acquires all the GPIOs defined under a given function.
3491 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3492 * no GPIO has been assigned to the requested function, or another IS_ERR()
3493 * code if an error occurred while trying to acquire the GPIOs.
3495 struct gpio_descs
*__must_check
gpiod_get_array(struct device
*dev
,
3497 enum gpiod_flags flags
)
3499 struct gpio_desc
*desc
;
3500 struct gpio_descs
*descs
;
3503 count
= gpiod_count(dev
, con_id
);
3505 return ERR_PTR(count
);
3507 descs
= kzalloc(sizeof(*descs
) + sizeof(descs
->desc
[0]) * count
,
3510 return ERR_PTR(-ENOMEM
);
3512 for (descs
->ndescs
= 0; descs
->ndescs
< count
; ) {
3513 desc
= gpiod_get_index(dev
, con_id
, descs
->ndescs
, flags
);
3515 gpiod_put_array(descs
);
3516 return ERR_CAST(desc
);
3518 descs
->desc
[descs
->ndescs
] = desc
;
3523 EXPORT_SYMBOL_GPL(gpiod_get_array
);
3526 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3528 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3529 * @con_id: function within the GPIO consumer
3530 * @flags: optional GPIO initialization flags
3532 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3533 * assigned to the requested function it will return NULL.
3535 struct gpio_descs
*__must_check
gpiod_get_array_optional(struct device
*dev
,
3537 enum gpiod_flags flags
)
3539 struct gpio_descs
*descs
;
3541 descs
= gpiod_get_array(dev
, con_id
, flags
);
3542 if (IS_ERR(descs
) && (PTR_ERR(descs
) == -ENOENT
))
3547 EXPORT_SYMBOL_GPL(gpiod_get_array_optional
);
3550 * gpiod_put - dispose of a GPIO descriptor
3551 * @desc: GPIO descriptor to dispose of
3553 * No descriptor can be used after gpiod_put() has been called on it.
3555 void gpiod_put(struct gpio_desc
*desc
)
3559 EXPORT_SYMBOL_GPL(gpiod_put
);
3562 * gpiod_put_array - dispose of multiple GPIO descriptors
3563 * @descs: struct gpio_descs containing an array of descriptors
3565 void gpiod_put_array(struct gpio_descs
*descs
)
3569 for (i
= 0; i
< descs
->ndescs
; i
++)
3570 gpiod_put(descs
->desc
[i
]);
3574 EXPORT_SYMBOL_GPL(gpiod_put_array
);
3576 static int __init
gpiolib_dev_init(void)
3580 /* Register GPIO sysfs bus */
3581 ret
= bus_register(&gpio_bus_type
);
3583 pr_err("gpiolib: could not register GPIO bus type\n");
3587 ret
= alloc_chrdev_region(&gpio_devt
, 0, GPIO_DEV_MAX
, "gpiochip");
3589 pr_err("gpiolib: failed to allocate char dev region\n");
3590 bus_unregister(&gpio_bus_type
);
3592 gpiolib_initialized
= true;
3593 gpiochip_setup_devs();
3597 core_initcall(gpiolib_dev_init
);
3599 #ifdef CONFIG_DEBUG_FS
3601 static void gpiolib_dbg_show(struct seq_file
*s
, struct gpio_device
*gdev
)
3604 struct gpio_chip
*chip
= gdev
->chip
;
3605 unsigned gpio
= gdev
->base
;
3606 struct gpio_desc
*gdesc
= &gdev
->descs
[0];
3610 for (i
= 0; i
< gdev
->ngpio
; i
++, gpio
++, gdesc
++) {
3611 if (!test_bit(FLAG_REQUESTED
, &gdesc
->flags
)) {
3613 seq_printf(s
, " gpio-%-3d (%-20.20s)\n",
3619 gpiod_get_direction(gdesc
);
3620 is_out
= test_bit(FLAG_IS_OUT
, &gdesc
->flags
);
3621 is_irq
= test_bit(FLAG_USED_AS_IRQ
, &gdesc
->flags
);
3622 seq_printf(s
, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3623 gpio
, gdesc
->name
? gdesc
->name
: "", gdesc
->label
,
3624 is_out
? "out" : "in ",
3626 ? (chip
->get(chip
, i
) ? "hi" : "lo")
3628 is_irq
? "IRQ" : " ");
3629 seq_printf(s
, "\n");
3633 static void *gpiolib_seq_start(struct seq_file
*s
, loff_t
*pos
)
3635 unsigned long flags
;
3636 struct gpio_device
*gdev
= NULL
;
3637 loff_t index
= *pos
;
3641 spin_lock_irqsave(&gpio_lock
, flags
);
3642 list_for_each_entry(gdev
, &gpio_devices
, list
)
3644 spin_unlock_irqrestore(&gpio_lock
, flags
);
3647 spin_unlock_irqrestore(&gpio_lock
, flags
);
3652 static void *gpiolib_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
3654 unsigned long flags
;
3655 struct gpio_device
*gdev
= v
;
3658 spin_lock_irqsave(&gpio_lock
, flags
);
3659 if (list_is_last(&gdev
->list
, &gpio_devices
))
3662 ret
= list_entry(gdev
->list
.next
, struct gpio_device
, list
);
3663 spin_unlock_irqrestore(&gpio_lock
, flags
);
3671 static void gpiolib_seq_stop(struct seq_file
*s
, void *v
)
3675 static int gpiolib_seq_show(struct seq_file
*s
, void *v
)
3677 struct gpio_device
*gdev
= v
;
3678 struct gpio_chip
*chip
= gdev
->chip
;
3679 struct device
*parent
;
3682 seq_printf(s
, "%s%s: (dangling chip)", (char *)s
->private,
3683 dev_name(&gdev
->dev
));
3687 seq_printf(s
, "%s%s: GPIOs %d-%d", (char *)s
->private,
3688 dev_name(&gdev
->dev
),
3689 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1);
3690 parent
= chip
->parent
;
3692 seq_printf(s
, ", parent: %s/%s",
3693 parent
->bus
? parent
->bus
->name
: "no-bus",
3696 seq_printf(s
, ", %s", chip
->label
);
3697 if (chip
->can_sleep
)
3698 seq_printf(s
, ", can sleep");
3699 seq_printf(s
, ":\n");
3702 chip
->dbg_show(s
, chip
);
3704 gpiolib_dbg_show(s
, gdev
);
3709 static const struct seq_operations gpiolib_seq_ops
= {
3710 .start
= gpiolib_seq_start
,
3711 .next
= gpiolib_seq_next
,
3712 .stop
= gpiolib_seq_stop
,
3713 .show
= gpiolib_seq_show
,
3716 static int gpiolib_open(struct inode
*inode
, struct file
*file
)
3718 return seq_open(file
, &gpiolib_seq_ops
);
3721 static const struct file_operations gpiolib_operations
= {
3722 .owner
= THIS_MODULE
,
3723 .open
= gpiolib_open
,
3725 .llseek
= seq_lseek
,
3726 .release
= seq_release
,
3729 static int __init
gpiolib_debugfs_init(void)
3731 /* /sys/kernel/debug/gpio */
3732 (void) debugfs_create_file("gpio", S_IFREG
| S_IRUGO
,
3733 NULL
, NULL
, &gpiolib_operations
);
3736 subsys_initcall(gpiolib_debugfs_init
);
3738 #endif /* DEBUG_FS */