1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/interrupt.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/device.h>
9 #include <linux/debugfs.h>
10 #include <linux/seq_file.h>
11 #include <linux/gpio.h>
12 #include <linux/of_gpio.h>
13 #include <linux/idr.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/gpio/machine.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/cdev.h>
21 #include <linux/uaccess.h>
22 #include <linux/compat.h>
23 #include <linux/anon_inodes.h>
24 #include <linux/file.h>
25 #include <linux/kfifo.h>
26 #include <linux/poll.h>
27 #include <linux/timekeeping.h>
28 #include <uapi/linux/gpio.h>
32 #define CREATE_TRACE_POINTS
33 #include <trace/events/gpio.h>
35 /* Implementation infrastructure for GPIO interfaces.
37 * The GPIO programming interface allows for inlining speed-critical
38 * get/set operations for common cases, so that access to SOC-integrated
39 * GPIOs can sometimes cost only an instruction or two per bit.
43 /* When debugging, extend minimal trust to callers and platform code.
44 * Also emit diagnostic messages that may help initial bringup, when
45 * board setup or driver bugs are most common.
47 * Otherwise, minimize overhead in what may be bitbanging codepaths.
50 #define extra_checks 1
52 #define extra_checks 0
55 /* Device and char device-related information */
56 static DEFINE_IDA(gpio_ida
);
57 static dev_t gpio_devt
;
58 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
59 static struct bus_type gpio_bus_type
= {
63 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
64 * While any GPIO is requested, its gpio_chip is not removable;
65 * each GPIO's "requested" flag serves as a lock and refcount.
67 DEFINE_SPINLOCK(gpio_lock
);
69 static DEFINE_MUTEX(gpio_lookup_lock
);
70 static LIST_HEAD(gpio_lookup_list
);
71 LIST_HEAD(gpio_devices
);
73 static void gpiochip_free_hogs(struct gpio_chip
*chip
);
74 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
);
75 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
);
76 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
);
78 static bool gpiolib_initialized
;
80 static inline void desc_set_label(struct gpio_desc
*d
, const char *label
)
86 * Convert a GPIO number to its descriptor
88 struct gpio_desc
*gpio_to_desc(unsigned gpio
)
90 struct gpio_device
*gdev
;
93 spin_lock_irqsave(&gpio_lock
, flags
);
95 list_for_each_entry(gdev
, &gpio_devices
, list
) {
96 if (gdev
->base
<= gpio
&&
97 gdev
->base
+ gdev
->ngpio
> gpio
) {
98 spin_unlock_irqrestore(&gpio_lock
, flags
);
99 return &gdev
->descs
[gpio
- gdev
->base
];
103 spin_unlock_irqrestore(&gpio_lock
, flags
);
105 if (!gpio_is_valid(gpio
))
106 WARN(1, "invalid GPIO %d\n", gpio
);
110 EXPORT_SYMBOL_GPL(gpio_to_desc
);
113 * Get the GPIO descriptor corresponding to the given hw number for this chip.
115 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
118 struct gpio_device
*gdev
= chip
->gpiodev
;
120 if (hwnum
>= gdev
->ngpio
)
121 return ERR_PTR(-EINVAL
);
123 return &gdev
->descs
[hwnum
];
127 * Convert a GPIO descriptor to the integer namespace.
128 * This should disappear in the future but is needed since we still
129 * use GPIO numbers for error messages and sysfs nodes
131 int desc_to_gpio(const struct gpio_desc
*desc
)
133 return desc
->gdev
->base
+ (desc
- &desc
->gdev
->descs
[0]);
135 EXPORT_SYMBOL_GPL(desc_to_gpio
);
139 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
140 * @desc: descriptor to return the chip of
142 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
144 if (!desc
|| !desc
->gdev
|| !desc
->gdev
->chip
)
146 return desc
->gdev
->chip
;
148 EXPORT_SYMBOL_GPL(gpiod_to_chip
);
150 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
151 static int gpiochip_find_base(int ngpio
)
153 struct gpio_device
*gdev
;
154 int base
= ARCH_NR_GPIOS
- ngpio
;
156 list_for_each_entry_reverse(gdev
, &gpio_devices
, list
) {
157 /* found a free space? */
158 if (gdev
->base
+ gdev
->ngpio
<= base
)
161 /* nope, check the space right before the chip */
162 base
= gdev
->base
- ngpio
;
165 if (gpio_is_valid(base
)) {
166 pr_debug("%s: found new base at %d\n", __func__
, base
);
169 pr_err("%s: cannot find free range\n", __func__
);
175 * gpiod_get_direction - return the current direction of a GPIO
176 * @desc: GPIO to get the direction of
178 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
180 * This function may sleep if gpiod_cansleep() is true.
182 int gpiod_get_direction(struct gpio_desc
*desc
)
184 struct gpio_chip
*chip
;
186 int status
= -EINVAL
;
188 chip
= gpiod_to_chip(desc
);
189 offset
= gpio_chip_hwgpio(desc
);
191 if (!chip
->get_direction
)
194 status
= chip
->get_direction(chip
, offset
);
196 /* GPIOF_DIR_IN, or other positive */
198 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
202 set_bit(FLAG_IS_OUT
, &desc
->flags
);
206 EXPORT_SYMBOL_GPL(gpiod_get_direction
);
209 * Add a new chip to the global chips list, keeping the list of chips sorted
210 * by range(means [base, base + ngpio - 1]) order.
212 * Return -EBUSY if the new chip overlaps with some other chip's integer
215 static int gpiodev_add_to_list(struct gpio_device
*gdev
)
217 struct gpio_device
*prev
, *next
;
219 if (list_empty(&gpio_devices
)) {
220 /* initial entry in list */
221 list_add_tail(&gdev
->list
, &gpio_devices
);
225 next
= list_entry(gpio_devices
.next
, struct gpio_device
, list
);
226 if (gdev
->base
+ gdev
->ngpio
<= next
->base
) {
227 /* add before first entry */
228 list_add(&gdev
->list
, &gpio_devices
);
232 prev
= list_entry(gpio_devices
.prev
, struct gpio_device
, list
);
233 if (prev
->base
+ prev
->ngpio
<= gdev
->base
) {
234 /* add behind last entry */
235 list_add_tail(&gdev
->list
, &gpio_devices
);
239 list_for_each_entry_safe(prev
, next
, &gpio_devices
, list
) {
240 /* at the end of the list */
241 if (&next
->list
== &gpio_devices
)
244 /* add between prev and next */
245 if (prev
->base
+ prev
->ngpio
<= gdev
->base
246 && gdev
->base
+ gdev
->ngpio
<= next
->base
) {
247 list_add(&gdev
->list
, &prev
->list
);
252 dev_err(&gdev
->dev
, "GPIO integer space overlap, cannot add chip\n");
257 * Convert a GPIO name to its descriptor
259 static struct gpio_desc
*gpio_name_to_desc(const char * const name
)
261 struct gpio_device
*gdev
;
264 spin_lock_irqsave(&gpio_lock
, flags
);
266 list_for_each_entry(gdev
, &gpio_devices
, list
) {
269 for (i
= 0; i
!= gdev
->ngpio
; ++i
) {
270 struct gpio_desc
*desc
= &gdev
->descs
[i
];
272 if (!desc
->name
|| !name
)
275 if (!strcmp(desc
->name
, name
)) {
276 spin_unlock_irqrestore(&gpio_lock
, flags
);
282 spin_unlock_irqrestore(&gpio_lock
, flags
);
288 * Takes the names from gc->names and checks if they are all unique. If they
289 * are, they are assigned to their gpio descriptors.
291 * Warning if one of the names is already used for a different GPIO.
293 static int gpiochip_set_desc_names(struct gpio_chip
*gc
)
295 struct gpio_device
*gdev
= gc
->gpiodev
;
301 /* First check all names if they are unique */
302 for (i
= 0; i
!= gc
->ngpio
; ++i
) {
303 struct gpio_desc
*gpio
;
305 gpio
= gpio_name_to_desc(gc
->names
[i
]);
308 "Detected name collision for GPIO name '%s'\n",
312 /* Then add all names to the GPIO descriptors */
313 for (i
= 0; i
!= gc
->ngpio
; ++i
)
314 gdev
->descs
[i
].name
= gc
->names
[i
];
320 * GPIO line handle management
324 * struct linehandle_state - contains the state of a userspace handle
325 * @gdev: the GPIO device the handle pertains to
326 * @label: consumer label used to tag descriptors
327 * @descs: the GPIO descriptors held by this handle
328 * @numdescs: the number of descriptors held in the descs array
330 struct linehandle_state
{
331 struct gpio_device
*gdev
;
333 struct gpio_desc
*descs
[GPIOHANDLES_MAX
];
337 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
338 (GPIOHANDLE_REQUEST_INPUT | \
339 GPIOHANDLE_REQUEST_OUTPUT | \
340 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
341 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
342 GPIOHANDLE_REQUEST_OPEN_SOURCE)
344 static long linehandle_ioctl(struct file
*filep
, unsigned int cmd
,
347 struct linehandle_state
*lh
= filep
->private_data
;
348 void __user
*ip
= (void __user
*)arg
;
349 struct gpiohandle_data ghd
;
352 if (cmd
== GPIOHANDLE_GET_LINE_VALUES_IOCTL
) {
355 memset(&ghd
, 0, sizeof(ghd
));
357 /* TODO: check if descriptors are really input */
358 for (i
= 0; i
< lh
->numdescs
; i
++) {
359 val
= gpiod_get_value_cansleep(lh
->descs
[i
]);
365 if (copy_to_user(ip
, &ghd
, sizeof(ghd
)))
369 } else if (cmd
== GPIOHANDLE_SET_LINE_VALUES_IOCTL
) {
370 int vals
[GPIOHANDLES_MAX
];
372 /* TODO: check if descriptors are really output */
373 if (copy_from_user(&ghd
, ip
, sizeof(ghd
)))
376 /* Clamp all values to [0,1] */
377 for (i
= 0; i
< lh
->numdescs
; i
++)
378 vals
[i
] = !!ghd
.values
[i
];
380 /* Reuse the array setting function */
381 gpiod_set_array_value_complex(false,
392 static long linehandle_ioctl_compat(struct file
*filep
, unsigned int cmd
,
395 return linehandle_ioctl(filep
, cmd
, (unsigned long)compat_ptr(arg
));
399 static int linehandle_release(struct inode
*inode
, struct file
*filep
)
401 struct linehandle_state
*lh
= filep
->private_data
;
402 struct gpio_device
*gdev
= lh
->gdev
;
405 for (i
= 0; i
< lh
->numdescs
; i
++)
406 gpiod_free(lh
->descs
[i
]);
409 put_device(&gdev
->dev
);
413 static const struct file_operations linehandle_fileops
= {
414 .release
= linehandle_release
,
415 .owner
= THIS_MODULE
,
416 .llseek
= noop_llseek
,
417 .unlocked_ioctl
= linehandle_ioctl
,
419 .compat_ioctl
= linehandle_ioctl_compat
,
423 static int linehandle_create(struct gpio_device
*gdev
, void __user
*ip
)
425 struct gpiohandle_request handlereq
;
426 struct linehandle_state
*lh
;
430 if (copy_from_user(&handlereq
, ip
, sizeof(handlereq
)))
432 if ((handlereq
.lines
== 0) || (handlereq
.lines
> GPIOHANDLES_MAX
))
435 lh
= kzalloc(sizeof(*lh
), GFP_KERNEL
);
439 get_device(&gdev
->dev
);
441 /* Make sure this is terminated */
442 handlereq
.consumer_label
[sizeof(handlereq
.consumer_label
)-1] = '\0';
443 if (strlen(handlereq
.consumer_label
)) {
444 lh
->label
= kstrdup(handlereq
.consumer_label
,
452 /* Request each GPIO */
453 for (i
= 0; i
< handlereq
.lines
; i
++) {
454 u32 offset
= handlereq
.lineoffsets
[i
];
455 u32 lflags
= handlereq
.flags
;
456 struct gpio_desc
*desc
;
458 if (offset
>= gdev
->ngpio
) {
463 /* Return an error if a unknown flag is set */
464 if (lflags
& ~GPIOHANDLE_REQUEST_VALID_FLAGS
) {
469 desc
= &gdev
->descs
[offset
];
470 ret
= gpiod_request(desc
, lh
->label
);
475 if (lflags
& GPIOHANDLE_REQUEST_ACTIVE_LOW
)
476 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
477 if (lflags
& GPIOHANDLE_REQUEST_OPEN_DRAIN
)
478 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
479 if (lflags
& GPIOHANDLE_REQUEST_OPEN_SOURCE
)
480 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
483 * Lines have to be requested explicitly for input
484 * or output, else the line will be treated "as is".
486 if (lflags
& GPIOHANDLE_REQUEST_OUTPUT
) {
487 int val
= !!handlereq
.default_values
[i
];
489 ret
= gpiod_direction_output(desc
, val
);
492 } else if (lflags
& GPIOHANDLE_REQUEST_INPUT
) {
493 ret
= gpiod_direction_input(desc
);
497 dev_dbg(&gdev
->dev
, "registered chardev handle for line %d\n",
500 /* Let i point at the last handle */
502 lh
->numdescs
= handlereq
.lines
;
504 fd
= get_unused_fd_flags(O_RDONLY
| O_CLOEXEC
);
510 file
= anon_inode_getfile("gpio-linehandle",
513 O_RDONLY
| O_CLOEXEC
);
516 goto out_put_unused_fd
;
520 if (copy_to_user(ip
, &handlereq
, sizeof(handlereq
))) {
522 * fput() will trigger the release() callback, so do not go onto
523 * the regular error cleanup path here.
530 fd_install(fd
, file
);
532 dev_dbg(&gdev
->dev
, "registered chardev handle for %d lines\n",
541 gpiod_free(lh
->descs
[i
]);
545 put_device(&gdev
->dev
);
550 * GPIO line event management
554 * struct lineevent_state - contains the state of a userspace event
555 * @gdev: the GPIO device the event pertains to
556 * @label: consumer label used to tag descriptors
557 * @desc: the GPIO descriptor held by this event
558 * @eflags: the event flags this line was requested with
559 * @irq: the interrupt that trigger in response to events on this GPIO
560 * @wait: wait queue that handles blocking reads of events
561 * @events: KFIFO for the GPIO events
562 * @read_lock: mutex lock to protect reads from colliding with adding
563 * new events to the FIFO
565 struct lineevent_state
{
566 struct gpio_device
*gdev
;
568 struct gpio_desc
*desc
;
571 wait_queue_head_t wait
;
572 DECLARE_KFIFO(events
, struct gpioevent_data
, 16);
573 struct mutex read_lock
;
576 #define GPIOEVENT_REQUEST_VALID_FLAGS \
577 (GPIOEVENT_REQUEST_RISING_EDGE | \
578 GPIOEVENT_REQUEST_FALLING_EDGE)
580 static unsigned int lineevent_poll(struct file
*filep
,
581 struct poll_table_struct
*wait
)
583 struct lineevent_state
*le
= filep
->private_data
;
584 unsigned int events
= 0;
586 poll_wait(filep
, &le
->wait
, wait
);
588 if (!kfifo_is_empty(&le
->events
))
589 events
= POLLIN
| POLLRDNORM
;
595 static ssize_t
lineevent_read(struct file
*filep
,
600 struct lineevent_state
*le
= filep
->private_data
;
604 if (count
< sizeof(struct gpioevent_data
))
608 if (kfifo_is_empty(&le
->events
)) {
609 if (filep
->f_flags
& O_NONBLOCK
)
612 ret
= wait_event_interruptible(le
->wait
,
613 !kfifo_is_empty(&le
->events
));
618 if (mutex_lock_interruptible(&le
->read_lock
))
620 ret
= kfifo_to_user(&le
->events
, buf
, count
, &copied
);
621 mutex_unlock(&le
->read_lock
);
627 * If we couldn't read anything from the fifo (a different
628 * thread might have been faster) we either return -EAGAIN if
629 * the file descriptor is non-blocking, otherwise we go back to
630 * sleep and wait for more data to arrive.
632 if (copied
== 0 && (filep
->f_flags
& O_NONBLOCK
))
635 } while (copied
== 0);
640 static int lineevent_release(struct inode
*inode
, struct file
*filep
)
642 struct lineevent_state
*le
= filep
->private_data
;
643 struct gpio_device
*gdev
= le
->gdev
;
645 free_irq(le
->irq
, le
);
646 gpiod_free(le
->desc
);
649 put_device(&gdev
->dev
);
653 static long lineevent_ioctl(struct file
*filep
, unsigned int cmd
,
656 struct lineevent_state
*le
= filep
->private_data
;
657 void __user
*ip
= (void __user
*)arg
;
658 struct gpiohandle_data ghd
;
661 * We can get the value for an event line but not set it,
662 * because it is input by definition.
664 if (cmd
== GPIOHANDLE_GET_LINE_VALUES_IOCTL
) {
667 memset(&ghd
, 0, sizeof(ghd
));
669 val
= gpiod_get_value_cansleep(le
->desc
);
674 if (copy_to_user(ip
, &ghd
, sizeof(ghd
)))
683 static long lineevent_ioctl_compat(struct file
*filep
, unsigned int cmd
,
686 return lineevent_ioctl(filep
, cmd
, (unsigned long)compat_ptr(arg
));
690 static const struct file_operations lineevent_fileops
= {
691 .release
= lineevent_release
,
692 .read
= lineevent_read
,
693 .poll
= lineevent_poll
,
694 .owner
= THIS_MODULE
,
695 .llseek
= noop_llseek
,
696 .unlocked_ioctl
= lineevent_ioctl
,
698 .compat_ioctl
= lineevent_ioctl_compat
,
702 static irqreturn_t
lineevent_irq_thread(int irq
, void *p
)
704 struct lineevent_state
*le
= p
;
705 struct gpioevent_data ge
;
708 ge
.timestamp
= ktime_get_real_ns();
710 if (le
->eflags
& GPIOEVENT_REQUEST_BOTH_EDGES
) {
711 int level
= gpiod_get_value_cansleep(le
->desc
);
714 /* Emit low-to-high event */
715 ge
.id
= GPIOEVENT_EVENT_RISING_EDGE
;
717 /* Emit high-to-low event */
718 ge
.id
= GPIOEVENT_EVENT_FALLING_EDGE
;
719 } else if (le
->eflags
& GPIOEVENT_REQUEST_RISING_EDGE
) {
720 /* Emit low-to-high event */
721 ge
.id
= GPIOEVENT_EVENT_RISING_EDGE
;
722 } else if (le
->eflags
& GPIOEVENT_REQUEST_FALLING_EDGE
) {
723 /* Emit high-to-low event */
724 ge
.id
= GPIOEVENT_EVENT_FALLING_EDGE
;
729 ret
= kfifo_put(&le
->events
, ge
);
731 wake_up_poll(&le
->wait
, POLLIN
);
736 static int lineevent_create(struct gpio_device
*gdev
, void __user
*ip
)
738 struct gpioevent_request eventreq
;
739 struct lineevent_state
*le
;
740 struct gpio_desc
*desc
;
749 if (copy_from_user(&eventreq
, ip
, sizeof(eventreq
)))
752 le
= kzalloc(sizeof(*le
), GFP_KERNEL
);
756 get_device(&gdev
->dev
);
758 /* Make sure this is terminated */
759 eventreq
.consumer_label
[sizeof(eventreq
.consumer_label
)-1] = '\0';
760 if (strlen(eventreq
.consumer_label
)) {
761 le
->label
= kstrdup(eventreq
.consumer_label
,
769 offset
= eventreq
.lineoffset
;
770 lflags
= eventreq
.handleflags
;
771 eflags
= eventreq
.eventflags
;
773 if (offset
>= gdev
->ngpio
) {
778 /* Return an error if a unknown flag is set */
779 if ((lflags
& ~GPIOHANDLE_REQUEST_VALID_FLAGS
) ||
780 (eflags
& ~GPIOEVENT_REQUEST_VALID_FLAGS
)) {
785 /* This is just wrong: we don't look for events on output lines */
786 if (lflags
& GPIOHANDLE_REQUEST_OUTPUT
) {
791 desc
= &gdev
->descs
[offset
];
792 ret
= gpiod_request(desc
, le
->label
);
798 if (lflags
& GPIOHANDLE_REQUEST_ACTIVE_LOW
)
799 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
800 if (lflags
& GPIOHANDLE_REQUEST_OPEN_DRAIN
)
801 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
802 if (lflags
& GPIOHANDLE_REQUEST_OPEN_SOURCE
)
803 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
805 ret
= gpiod_direction_input(desc
);
809 le
->irq
= gpiod_to_irq(desc
);
815 if (eflags
& GPIOEVENT_REQUEST_RISING_EDGE
)
816 irqflags
|= IRQF_TRIGGER_RISING
;
817 if (eflags
& GPIOEVENT_REQUEST_FALLING_EDGE
)
818 irqflags
|= IRQF_TRIGGER_FALLING
;
819 irqflags
|= IRQF_ONESHOT
;
820 irqflags
|= IRQF_SHARED
;
822 INIT_KFIFO(le
->events
);
823 init_waitqueue_head(&le
->wait
);
824 mutex_init(&le
->read_lock
);
826 /* Request a thread to read the events */
827 ret
= request_threaded_irq(le
->irq
,
829 lineevent_irq_thread
,
836 fd
= get_unused_fd_flags(O_RDONLY
| O_CLOEXEC
);
842 file
= anon_inode_getfile("gpio-event",
845 O_RDONLY
| O_CLOEXEC
);
848 goto out_put_unused_fd
;
852 if (copy_to_user(ip
, &eventreq
, sizeof(eventreq
))) {
854 * fput() will trigger the release() callback, so do not go onto
855 * the regular error cleanup path here.
862 fd_install(fd
, file
);
869 free_irq(le
->irq
, le
);
871 gpiod_free(le
->desc
);
876 put_device(&gdev
->dev
);
881 * gpio_ioctl() - ioctl handler for the GPIO chardev
883 static long gpio_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
885 struct gpio_device
*gdev
= filp
->private_data
;
886 struct gpio_chip
*chip
= gdev
->chip
;
887 void __user
*ip
= (void __user
*)arg
;
889 /* We fail any subsequent ioctl():s when the chip is gone */
893 /* Fill in the struct and pass to userspace */
894 if (cmd
== GPIO_GET_CHIPINFO_IOCTL
) {
895 struct gpiochip_info chipinfo
;
897 memset(&chipinfo
, 0, sizeof(chipinfo
));
899 strncpy(chipinfo
.name
, dev_name(&gdev
->dev
),
900 sizeof(chipinfo
.name
));
901 chipinfo
.name
[sizeof(chipinfo
.name
)-1] = '\0';
902 strncpy(chipinfo
.label
, gdev
->label
,
903 sizeof(chipinfo
.label
));
904 chipinfo
.label
[sizeof(chipinfo
.label
)-1] = '\0';
905 chipinfo
.lines
= gdev
->ngpio
;
906 if (copy_to_user(ip
, &chipinfo
, sizeof(chipinfo
)))
909 } else if (cmd
== GPIO_GET_LINEINFO_IOCTL
) {
910 struct gpioline_info lineinfo
;
911 struct gpio_desc
*desc
;
913 if (copy_from_user(&lineinfo
, ip
, sizeof(lineinfo
)))
915 if (lineinfo
.line_offset
>= gdev
->ngpio
)
918 desc
= &gdev
->descs
[lineinfo
.line_offset
];
920 strncpy(lineinfo
.name
, desc
->name
,
921 sizeof(lineinfo
.name
));
922 lineinfo
.name
[sizeof(lineinfo
.name
)-1] = '\0';
924 lineinfo
.name
[0] = '\0';
927 strncpy(lineinfo
.consumer
, desc
->label
,
928 sizeof(lineinfo
.consumer
));
929 lineinfo
.consumer
[sizeof(lineinfo
.consumer
)-1] = '\0';
931 lineinfo
.consumer
[0] = '\0';
935 * Userspace only need to know that the kernel is using
936 * this GPIO so it can't use it.
939 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) ||
940 test_bit(FLAG_IS_HOGGED
, &desc
->flags
) ||
941 test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
) ||
942 test_bit(FLAG_EXPORT
, &desc
->flags
) ||
943 test_bit(FLAG_SYSFS
, &desc
->flags
))
944 lineinfo
.flags
|= GPIOLINE_FLAG_KERNEL
;
945 if (test_bit(FLAG_IS_OUT
, &desc
->flags
))
946 lineinfo
.flags
|= GPIOLINE_FLAG_IS_OUT
;
947 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
948 lineinfo
.flags
|= GPIOLINE_FLAG_ACTIVE_LOW
;
949 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
950 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_DRAIN
;
951 if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
952 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_SOURCE
;
954 if (copy_to_user(ip
, &lineinfo
, sizeof(lineinfo
)))
957 } else if (cmd
== GPIO_GET_LINEHANDLE_IOCTL
) {
958 return linehandle_create(gdev
, ip
);
959 } else if (cmd
== GPIO_GET_LINEEVENT_IOCTL
) {
960 return lineevent_create(gdev
, ip
);
966 static long gpio_ioctl_compat(struct file
*filp
, unsigned int cmd
,
969 return gpio_ioctl(filp
, cmd
, (unsigned long)compat_ptr(arg
));
974 * gpio_chrdev_open() - open the chardev for ioctl operations
975 * @inode: inode for this chardev
976 * @filp: file struct for storing private data
977 * Returns 0 on success
979 static int gpio_chrdev_open(struct inode
*inode
, struct file
*filp
)
981 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
982 struct gpio_device
, chrdev
);
984 /* Fail on open if the backing gpiochip is gone */
985 if (!gdev
|| !gdev
->chip
)
987 get_device(&gdev
->dev
);
988 filp
->private_data
= gdev
;
990 return nonseekable_open(inode
, filp
);
994 * gpio_chrdev_release() - close chardev after ioctl operations
995 * @inode: inode for this chardev
996 * @filp: file struct for storing private data
997 * Returns 0 on success
999 static int gpio_chrdev_release(struct inode
*inode
, struct file
*filp
)
1001 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
1002 struct gpio_device
, chrdev
);
1006 put_device(&gdev
->dev
);
1011 static const struct file_operations gpio_fileops
= {
1012 .release
= gpio_chrdev_release
,
1013 .open
= gpio_chrdev_open
,
1014 .owner
= THIS_MODULE
,
1015 .llseek
= no_llseek
,
1016 .unlocked_ioctl
= gpio_ioctl
,
1017 #ifdef CONFIG_COMPAT
1018 .compat_ioctl
= gpio_ioctl_compat
,
1022 static void gpiodevice_release(struct device
*dev
)
1024 struct gpio_device
*gdev
= dev_get_drvdata(dev
);
1026 list_del(&gdev
->list
);
1027 ida_simple_remove(&gpio_ida
, gdev
->id
);
1033 static int gpiochip_setup_dev(struct gpio_device
*gdev
)
1037 cdev_init(&gdev
->chrdev
, &gpio_fileops
);
1038 gdev
->chrdev
.owner
= THIS_MODULE
;
1039 gdev
->chrdev
.kobj
.parent
= &gdev
->dev
.kobj
;
1040 gdev
->dev
.devt
= MKDEV(MAJOR(gpio_devt
), gdev
->id
);
1041 status
= cdev_add(&gdev
->chrdev
, gdev
->dev
.devt
, 1);
1043 chip_warn(gdev
->chip
, "failed to add char device %d:%d\n",
1044 MAJOR(gpio_devt
), gdev
->id
);
1046 chip_dbg(gdev
->chip
, "added GPIO chardev (%d:%d)\n",
1047 MAJOR(gpio_devt
), gdev
->id
);
1048 status
= device_add(&gdev
->dev
);
1050 goto err_remove_chardev
;
1052 status
= gpiochip_sysfs_register(gdev
);
1054 goto err_remove_device
;
1056 /* From this point, the .release() function cleans up gpio_device */
1057 gdev
->dev
.release
= gpiodevice_release
;
1058 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1059 __func__
, gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
1060 dev_name(&gdev
->dev
), gdev
->chip
->label
? : "generic");
1065 device_del(&gdev
->dev
);
1067 cdev_del(&gdev
->chrdev
);
1071 static void gpiochip_setup_devs(void)
1073 struct gpio_device
*gdev
;
1076 list_for_each_entry(gdev
, &gpio_devices
, list
) {
1077 err
= gpiochip_setup_dev(gdev
);
1079 pr_err("%s: Failed to initialize gpio device (%d)\n",
1080 dev_name(&gdev
->dev
), err
);
1085 * gpiochip_add_data() - register a gpio_chip
1086 * @chip: the chip to register, with chip->base initialized
1087 * Context: potentially before irqs will work
1089 * Returns a negative errno if the chip can't be registered, such as
1090 * because the chip->base is invalid or already associated with a
1091 * different chip. Otherwise it returns zero as a success code.
1093 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1094 * can be freely used, the chip->parent device must be registered before
1095 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1096 * for GPIOs will fail rudely.
1098 * gpiochip_add_data() must only be called after gpiolib initialization,
1099 * ie after core_initcall().
1101 * If chip->base is negative, this requests dynamic assignment of
1102 * a range of valid GPIOs.
1104 int gpiochip_add_data(struct gpio_chip
*chip
, void *data
)
1106 unsigned long flags
;
1109 int base
= chip
->base
;
1110 struct gpio_device
*gdev
;
1113 * First: allocate and populate the internal stat container, and
1114 * set up the struct device.
1116 gdev
= kzalloc(sizeof(*gdev
), GFP_KERNEL
);
1119 gdev
->dev
.bus
= &gpio_bus_type
;
1121 chip
->gpiodev
= gdev
;
1123 gdev
->dev
.parent
= chip
->parent
;
1124 gdev
->dev
.of_node
= chip
->parent
->of_node
;
1127 #ifdef CONFIG_OF_GPIO
1128 /* If the gpiochip has an assigned OF node this takes precedence */
1130 gdev
->dev
.of_node
= chip
->of_node
;
1133 gdev
->id
= ida_simple_get(&gpio_ida
, 0, 0, GFP_KERNEL
);
1138 dev_set_name(&gdev
->dev
, "gpiochip%d", gdev
->id
);
1139 device_initialize(&gdev
->dev
);
1140 dev_set_drvdata(&gdev
->dev
, gdev
);
1141 if (chip
->parent
&& chip
->parent
->driver
)
1142 gdev
->owner
= chip
->parent
->driver
->owner
;
1143 else if (chip
->owner
)
1144 /* TODO: remove chip->owner */
1145 gdev
->owner
= chip
->owner
;
1147 gdev
->owner
= THIS_MODULE
;
1149 gdev
->descs
= kcalloc(chip
->ngpio
, sizeof(gdev
->descs
[0]), GFP_KERNEL
);
1155 if (chip
->ngpio
== 0) {
1156 chip_err(chip
, "tried to insert a GPIO chip with zero lines\n");
1158 goto err_free_descs
;
1162 gdev
->label
= kstrdup(chip
->label
, GFP_KERNEL
);
1164 gdev
->label
= kstrdup("unknown", GFP_KERNEL
);
1167 goto err_free_descs
;
1170 gdev
->ngpio
= chip
->ngpio
;
1173 spin_lock_irqsave(&gpio_lock
, flags
);
1176 * TODO: this allocates a Linux GPIO number base in the global
1177 * GPIO numberspace for this chip. In the long run we want to
1178 * get *rid* of this numberspace and use only descriptors, but
1179 * it may be a pipe dream. It will not happen before we get rid
1180 * of the sysfs interface anyways.
1183 base
= gpiochip_find_base(chip
->ngpio
);
1186 spin_unlock_irqrestore(&gpio_lock
, flags
);
1187 goto err_free_label
;
1190 * TODO: it should not be necessary to reflect the assigned
1191 * base outside of the GPIO subsystem. Go over drivers and
1192 * see if anyone makes use of this, else drop this and assign
1199 status
= gpiodev_add_to_list(gdev
);
1201 spin_unlock_irqrestore(&gpio_lock
, flags
);
1202 goto err_free_label
;
1205 spin_unlock_irqrestore(&gpio_lock
, flags
);
1207 for (i
= 0; i
< chip
->ngpio
; i
++) {
1208 struct gpio_desc
*desc
= &gdev
->descs
[i
];
1212 * REVISIT: most hardware initializes GPIOs as inputs
1213 * (often with pullups enabled) so power usage is
1214 * minimized. Linux code should set the gpio direction
1215 * first thing; but until it does, and in case
1216 * chip->get_direction is not set, we may expose the
1217 * wrong direction in sysfs.
1220 if (chip
->get_direction
) {
1222 * If we have .get_direction, set up the initial
1223 * direction flag from the hardware.
1225 int dir
= chip
->get_direction(chip
, i
);
1228 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1229 } else if (!chip
->direction_input
) {
1231 * If the chip lacks the .direction_input callback
1232 * we logically assume all lines are outputs.
1234 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1238 #ifdef CONFIG_PINCTRL
1239 INIT_LIST_HEAD(&gdev
->pin_ranges
);
1242 status
= gpiochip_set_desc_names(chip
);
1244 goto err_remove_from_list
;
1246 status
= gpiochip_irqchip_init_valid_mask(chip
);
1248 goto err_remove_from_list
;
1250 status
= of_gpiochip_add(chip
);
1252 goto err_remove_chip
;
1254 acpi_gpiochip_add(chip
);
1257 * By first adding the chardev, and then adding the device,
1258 * we get a device node entry in sysfs under
1259 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1260 * coldplug of device nodes and other udev business.
1261 * We can do this only if gpiolib has been initialized.
1262 * Otherwise, defer until later.
1264 if (gpiolib_initialized
) {
1265 status
= gpiochip_setup_dev(gdev
);
1267 goto err_remove_chip
;
1272 acpi_gpiochip_remove(chip
);
1273 gpiochip_free_hogs(chip
);
1274 of_gpiochip_remove(chip
);
1275 gpiochip_irqchip_free_valid_mask(chip
);
1276 err_remove_from_list
:
1277 spin_lock_irqsave(&gpio_lock
, flags
);
1278 list_del(&gdev
->list
);
1279 spin_unlock_irqrestore(&gpio_lock
, flags
);
1285 ida_simple_remove(&gpio_ida
, gdev
->id
);
1286 /* failures here can mean systems won't boot... */
1287 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__
,
1288 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
1289 chip
->label
? : "generic");
1293 EXPORT_SYMBOL_GPL(gpiochip_add_data
);
1296 * gpiochip_get_data() - get per-subdriver data for the chip
1298 void *gpiochip_get_data(struct gpio_chip
*chip
)
1300 return chip
->gpiodev
->data
;
1302 EXPORT_SYMBOL_GPL(gpiochip_get_data
);
1305 * gpiochip_remove() - unregister a gpio_chip
1306 * @chip: the chip to unregister
1308 * A gpio_chip with any GPIOs still requested may not be removed.
1310 void gpiochip_remove(struct gpio_chip
*chip
)
1312 struct gpio_device
*gdev
= chip
->gpiodev
;
1313 struct gpio_desc
*desc
;
1314 unsigned long flags
;
1316 bool requested
= false;
1318 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1319 gpiochip_sysfs_unregister(gdev
);
1320 gpiochip_free_hogs(chip
);
1321 /* Numb the device, cancelling all outstanding operations */
1323 gpiochip_irqchip_remove(chip
);
1324 acpi_gpiochip_remove(chip
);
1325 gpiochip_remove_pin_ranges(chip
);
1326 of_gpiochip_remove(chip
);
1328 * We accept no more calls into the driver from this point, so
1329 * NULL the driver data pointer
1333 spin_lock_irqsave(&gpio_lock
, flags
);
1334 for (i
= 0; i
< gdev
->ngpio
; i
++) {
1335 desc
= &gdev
->descs
[i
];
1336 if (test_bit(FLAG_REQUESTED
, &desc
->flags
))
1339 spin_unlock_irqrestore(&gpio_lock
, flags
);
1342 dev_crit(&gdev
->dev
,
1343 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1346 * The gpiochip side puts its use of the device to rest here:
1347 * if there are no userspace clients, the chardev and device will
1348 * be removed, else it will be dangling until the last user is
1351 cdev_del(&gdev
->chrdev
);
1352 device_del(&gdev
->dev
);
1353 put_device(&gdev
->dev
);
1355 EXPORT_SYMBOL_GPL(gpiochip_remove
);
1357 static void devm_gpio_chip_release(struct device
*dev
, void *res
)
1359 struct gpio_chip
*chip
= *(struct gpio_chip
**)res
;
1361 gpiochip_remove(chip
);
1364 static int devm_gpio_chip_match(struct device
*dev
, void *res
, void *data
)
1367 struct gpio_chip
**r
= res
;
1378 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1379 * @dev: the device pointer on which irq_chip belongs to.
1380 * @chip: the chip to register, with chip->base initialized
1381 * Context: potentially before irqs will work
1383 * Returns a negative errno if the chip can't be registered, such as
1384 * because the chip->base is invalid or already associated with a
1385 * different chip. Otherwise it returns zero as a success code.
1387 * The gpio chip automatically be released when the device is unbound.
1389 int devm_gpiochip_add_data(struct device
*dev
, struct gpio_chip
*chip
,
1392 struct gpio_chip
**ptr
;
1395 ptr
= devres_alloc(devm_gpio_chip_release
, sizeof(*ptr
),
1400 ret
= gpiochip_add_data(chip
, data
);
1407 devres_add(dev
, ptr
);
1411 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data
);
1414 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1415 * @dev: device for which which resource was allocated
1416 * @chip: the chip to remove
1418 * A gpio_chip with any GPIOs still requested may not be removed.
1420 void devm_gpiochip_remove(struct device
*dev
, struct gpio_chip
*chip
)
1424 ret
= devres_release(dev
, devm_gpio_chip_release
,
1425 devm_gpio_chip_match
, chip
);
1429 EXPORT_SYMBOL_GPL(devm_gpiochip_remove
);
1432 * gpiochip_find() - iterator for locating a specific gpio_chip
1433 * @data: data to pass to match function
1434 * @callback: Callback function to check gpio_chip
1436 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1437 * determined by a user supplied @match callback. The callback should return
1438 * 0 if the device doesn't match and non-zero if it does. If the callback is
1439 * non-zero, this function will return to the caller and not iterate over any
1442 struct gpio_chip
*gpiochip_find(void *data
,
1443 int (*match
)(struct gpio_chip
*chip
,
1446 struct gpio_device
*gdev
;
1447 struct gpio_chip
*chip
= NULL
;
1448 unsigned long flags
;
1450 spin_lock_irqsave(&gpio_lock
, flags
);
1451 list_for_each_entry(gdev
, &gpio_devices
, list
)
1452 if (gdev
->chip
&& match(gdev
->chip
, data
)) {
1457 spin_unlock_irqrestore(&gpio_lock
, flags
);
1461 EXPORT_SYMBOL_GPL(gpiochip_find
);
1463 static int gpiochip_match_name(struct gpio_chip
*chip
, void *data
)
1465 const char *name
= data
;
1467 return !strcmp(chip
->label
, name
);
1470 static struct gpio_chip
*find_chip_by_name(const char *name
)
1472 return gpiochip_find((void *)name
, gpiochip_match_name
);
1475 #ifdef CONFIG_GPIOLIB_IRQCHIP
1478 * The following is irqchip helper code for gpiochips.
1481 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
)
1485 if (!gpiochip
->irq_need_valid_mask
)
1488 gpiochip
->irq_valid_mask
= kcalloc(BITS_TO_LONGS(gpiochip
->ngpio
),
1489 sizeof(long), GFP_KERNEL
);
1490 if (!gpiochip
->irq_valid_mask
)
1493 /* Assume by default all GPIOs are valid */
1494 for (i
= 0; i
< gpiochip
->ngpio
; i
++)
1495 set_bit(i
, gpiochip
->irq_valid_mask
);
1500 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
)
1502 kfree(gpiochip
->irq_valid_mask
);
1503 gpiochip
->irq_valid_mask
= NULL
;
1506 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip
*gpiochip
,
1507 unsigned int offset
)
1509 /* No mask means all valid */
1510 if (likely(!gpiochip
->irq_valid_mask
))
1512 return test_bit(offset
, gpiochip
->irq_valid_mask
);
1516 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1517 * @gpiochip: the gpiochip to set the irqchip chain to
1518 * @irqchip: the irqchip to chain to the gpiochip
1519 * @parent_irq: the irq number corresponding to the parent IRQ for this
1521 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1522 * coming out of the gpiochip. If the interrupt is nested rather than
1523 * cascaded, pass NULL in this handler argument
1525 static void gpiochip_set_cascaded_irqchip(struct gpio_chip
*gpiochip
,
1526 struct irq_chip
*irqchip
,
1528 irq_flow_handler_t parent_handler
)
1530 unsigned int offset
;
1532 if (!gpiochip
->irqdomain
) {
1533 chip_err(gpiochip
, "called %s before setting up irqchip\n",
1538 if (parent_handler
) {
1539 if (gpiochip
->can_sleep
) {
1541 "you cannot have chained interrupts on a "
1542 "chip that may sleep\n");
1546 * The parent irqchip is already using the chip_data for this
1547 * irqchip, so our callbacks simply use the handler_data.
1549 irq_set_chained_handler_and_data(parent_irq
, parent_handler
,
1552 gpiochip
->irq_chained_parent
= parent_irq
;
1555 /* Set the parent IRQ for all affected IRQs */
1556 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1557 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1559 irq_set_parent(irq_find_mapping(gpiochip
->irqdomain
, offset
),
1565 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1566 * @gpiochip: the gpiochip to set the irqchip chain to
1567 * @irqchip: the irqchip to chain to the gpiochip
1568 * @parent_irq: the irq number corresponding to the parent IRQ for this
1570 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1571 * coming out of the gpiochip. If the interrupt is nested rather than
1572 * cascaded, pass NULL in this handler argument
1574 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
1575 struct irq_chip
*irqchip
,
1577 irq_flow_handler_t parent_handler
)
1579 gpiochip_set_cascaded_irqchip(gpiochip
, irqchip
, parent_irq
,
1582 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip
);
1585 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1586 * @gpiochip: the gpiochip to set the irqchip nested handler to
1587 * @irqchip: the irqchip to nest to the gpiochip
1588 * @parent_irq: the irq number corresponding to the parent IRQ for this
1591 void gpiochip_set_nested_irqchip(struct gpio_chip
*gpiochip
,
1592 struct irq_chip
*irqchip
,
1595 if (!gpiochip
->irq_nested
) {
1596 chip_err(gpiochip
, "tried to nest a chained gpiochip\n");
1599 gpiochip_set_cascaded_irqchip(gpiochip
, irqchip
, parent_irq
,
1602 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip
);
1605 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1606 * @d: the irqdomain used by this irqchip
1607 * @irq: the global irq number used by this GPIO irqchip irq
1608 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1610 * This function will set up the mapping for a certain IRQ line on a
1611 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1612 * stored inside the gpiochip.
1614 static int gpiochip_irq_map(struct irq_domain
*d
, unsigned int irq
,
1615 irq_hw_number_t hwirq
)
1617 struct gpio_chip
*chip
= d
->host_data
;
1619 irq_set_chip_data(irq
, chip
);
1621 * This lock class tells lockdep that GPIO irqs are in a different
1622 * category than their parents, so it won't report false recursion.
1624 irq_set_lockdep_class(irq
, chip
->lock_key
);
1625 irq_set_chip_and_handler(irq
, chip
->irqchip
, chip
->irq_handler
);
1626 /* Chips that use nested thread handlers have them marked */
1627 if (chip
->irq_nested
)
1628 irq_set_nested_thread(irq
, 1);
1629 irq_set_noprobe(irq
);
1632 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1633 * is passed as default type.
1635 if (chip
->irq_default_type
!= IRQ_TYPE_NONE
)
1636 irq_set_irq_type(irq
, chip
->irq_default_type
);
1641 static void gpiochip_irq_unmap(struct irq_domain
*d
, unsigned int irq
)
1643 struct gpio_chip
*chip
= d
->host_data
;
1645 if (chip
->irq_nested
)
1646 irq_set_nested_thread(irq
, 0);
1647 irq_set_chip_and_handler(irq
, NULL
, NULL
);
1648 irq_set_chip_data(irq
, NULL
);
1651 static const struct irq_domain_ops gpiochip_domain_ops
= {
1652 .map
= gpiochip_irq_map
,
1653 .unmap
= gpiochip_irq_unmap
,
1654 /* Virtually all GPIO irqchips are twocell:ed */
1655 .xlate
= irq_domain_xlate_twocell
,
1658 static int gpiochip_irq_reqres(struct irq_data
*d
)
1660 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1662 if (!try_module_get(chip
->gpiodev
->owner
))
1665 if (gpiochip_lock_as_irq(chip
, d
->hwirq
)) {
1667 "unable to lock HW IRQ %lu for IRQ\n",
1669 module_put(chip
->gpiodev
->owner
);
1675 static void gpiochip_irq_relres(struct irq_data
*d
)
1677 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1679 gpiochip_unlock_as_irq(chip
, d
->hwirq
);
1680 module_put(chip
->gpiodev
->owner
);
1683 static int gpiochip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
1685 return irq_find_mapping(chip
->irqdomain
, offset
);
1689 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1690 * @gpiochip: the gpiochip to remove the irqchip from
1692 * This is called only from gpiochip_remove()
1694 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
)
1696 unsigned int offset
;
1698 acpi_gpiochip_free_interrupts(gpiochip
);
1700 if (gpiochip
->irq_chained_parent
) {
1701 irq_set_chained_handler(gpiochip
->irq_chained_parent
, NULL
);
1702 irq_set_handler_data(gpiochip
->irq_chained_parent
, NULL
);
1705 /* Remove all IRQ mappings and delete the domain */
1706 if (gpiochip
->irqdomain
) {
1707 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1708 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1710 irq_dispose_mapping(
1711 irq_find_mapping(gpiochip
->irqdomain
, offset
));
1713 irq_domain_remove(gpiochip
->irqdomain
);
1716 if (gpiochip
->irqchip
) {
1717 gpiochip
->irqchip
->irq_request_resources
= NULL
;
1718 gpiochip
->irqchip
->irq_release_resources
= NULL
;
1719 gpiochip
->irqchip
= NULL
;
1722 gpiochip_irqchip_free_valid_mask(gpiochip
);
1726 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1727 * @gpiochip: the gpiochip to add the irqchip to
1728 * @irqchip: the irqchip to add to the gpiochip
1729 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1730 * allocate gpiochip irqs from
1731 * @handler: the irq handler to use (often a predefined irq core function)
1732 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1733 * to have the core avoid setting up any default type in the hardware.
1734 * @nested: whether this is a nested irqchip calling handle_nested_irq()
1735 * in its IRQ handler
1736 * @lock_key: lockdep class
1738 * This function closely associates a certain irqchip with a certain
1739 * gpiochip, providing an irq domain to translate the local IRQs to
1740 * global irqs in the gpiolib core, and making sure that the gpiochip
1741 * is passed as chip data to all related functions. Driver callbacks
1742 * need to use gpiochip_get_data() to get their local state containers back
1743 * from the gpiochip passed as chip data. An irqdomain will be stored
1744 * in the gpiochip that shall be used by the driver to handle IRQ number
1745 * translation. The gpiochip will need to be initialized and registered
1746 * before calling this function.
1748 * This function will handle two cell:ed simple IRQs and assumes all
1749 * the pins on the gpiochip can generate a unique IRQ. Everything else
1750 * need to be open coded.
1752 int gpiochip_irqchip_add_key(struct gpio_chip
*gpiochip
,
1753 struct irq_chip
*irqchip
,
1754 unsigned int first_irq
,
1755 irq_flow_handler_t handler
,
1758 struct lock_class_key
*lock_key
)
1760 struct device_node
*of_node
;
1761 bool irq_base_set
= false;
1762 unsigned int offset
;
1763 unsigned irq_base
= 0;
1765 if (!gpiochip
|| !irqchip
)
1768 if (!gpiochip
->parent
) {
1769 pr_err("missing gpiochip .dev parent pointer\n");
1772 gpiochip
->irq_nested
= nested
;
1773 of_node
= gpiochip
->parent
->of_node
;
1774 #ifdef CONFIG_OF_GPIO
1776 * If the gpiochip has an assigned OF node this takes precedence
1777 * FIXME: get rid of this and use gpiochip->parent->of_node
1780 if (gpiochip
->of_node
)
1781 of_node
= gpiochip
->of_node
;
1784 * Specifying a default trigger is a terrible idea if DT or ACPI is
1785 * used to configure the interrupts, as you may end-up with
1786 * conflicting triggers. Tell the user, and reset to NONE.
1788 if (WARN(of_node
&& type
!= IRQ_TYPE_NONE
,
1789 "%s: Ignoring %d default trigger\n", of_node
->full_name
, type
))
1790 type
= IRQ_TYPE_NONE
;
1791 if (has_acpi_companion(gpiochip
->parent
) && type
!= IRQ_TYPE_NONE
) {
1792 acpi_handle_warn(ACPI_HANDLE(gpiochip
->parent
),
1793 "Ignoring %d default trigger\n", type
);
1794 type
= IRQ_TYPE_NONE
;
1797 gpiochip
->irqchip
= irqchip
;
1798 gpiochip
->irq_handler
= handler
;
1799 gpiochip
->irq_default_type
= type
;
1800 gpiochip
->to_irq
= gpiochip_to_irq
;
1801 gpiochip
->lock_key
= lock_key
;
1802 gpiochip
->irqdomain
= irq_domain_add_simple(of_node
,
1803 gpiochip
->ngpio
, first_irq
,
1804 &gpiochip_domain_ops
, gpiochip
);
1805 if (!gpiochip
->irqdomain
) {
1806 gpiochip
->irqchip
= NULL
;
1811 * It is possible for a driver to override this, but only if the
1812 * alternative functions are both implemented.
1814 if (!irqchip
->irq_request_resources
&&
1815 !irqchip
->irq_release_resources
) {
1816 irqchip
->irq_request_resources
= gpiochip_irq_reqres
;
1817 irqchip
->irq_release_resources
= gpiochip_irq_relres
;
1821 * Prepare the mapping since the irqchip shall be orthogonal to
1822 * any gpiochip calls. If the first_irq was zero, this is
1823 * necessary to allocate descriptors for all IRQs.
1825 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1826 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1828 irq_base
= irq_create_mapping(gpiochip
->irqdomain
, offset
);
1829 if (!irq_base_set
) {
1831 * Store the base into the gpiochip to be used when
1832 * unmapping the irqs.
1834 gpiochip
->irq_base
= irq_base
;
1835 irq_base_set
= true;
1839 acpi_gpiochip_request_interrupts(gpiochip
);
1843 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key
);
1845 #else /* CONFIG_GPIOLIB_IRQCHIP */
1847 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
) {}
1848 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
)
1852 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
)
1855 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1858 * gpiochip_generic_request() - request the gpio function for a pin
1859 * @chip: the gpiochip owning the GPIO
1860 * @offset: the offset of the GPIO to request for GPIO function
1862 int gpiochip_generic_request(struct gpio_chip
*chip
, unsigned offset
)
1864 return pinctrl_request_gpio(chip
->gpiodev
->base
+ offset
);
1866 EXPORT_SYMBOL_GPL(gpiochip_generic_request
);
1869 * gpiochip_generic_free() - free the gpio function from a pin
1870 * @chip: the gpiochip to request the gpio function for
1871 * @offset: the offset of the GPIO to free from GPIO function
1873 void gpiochip_generic_free(struct gpio_chip
*chip
, unsigned offset
)
1875 pinctrl_free_gpio(chip
->gpiodev
->base
+ offset
);
1877 EXPORT_SYMBOL_GPL(gpiochip_generic_free
);
1880 * gpiochip_generic_config() - apply configuration for a pin
1881 * @chip: the gpiochip owning the GPIO
1882 * @offset: the offset of the GPIO to apply the configuration
1883 * @config: the configuration to be applied
1885 int gpiochip_generic_config(struct gpio_chip
*chip
, unsigned offset
,
1886 unsigned long config
)
1888 return pinctrl_gpio_set_config(chip
->gpiodev
->base
+ offset
, config
);
1890 EXPORT_SYMBOL_GPL(gpiochip_generic_config
);
1892 #ifdef CONFIG_PINCTRL
1895 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1896 * @chip: the gpiochip to add the range for
1897 * @pctldev: the pin controller to map to
1898 * @gpio_offset: the start offset in the current gpio_chip number space
1899 * @pin_group: name of the pin group inside the pin controller
1901 int gpiochip_add_pingroup_range(struct gpio_chip
*chip
,
1902 struct pinctrl_dev
*pctldev
,
1903 unsigned int gpio_offset
, const char *pin_group
)
1905 struct gpio_pin_range
*pin_range
;
1906 struct gpio_device
*gdev
= chip
->gpiodev
;
1909 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1911 chip_err(chip
, "failed to allocate pin ranges\n");
1915 /* Use local offset as range ID */
1916 pin_range
->range
.id
= gpio_offset
;
1917 pin_range
->range
.gc
= chip
;
1918 pin_range
->range
.name
= chip
->label
;
1919 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1920 pin_range
->pctldev
= pctldev
;
1922 ret
= pinctrl_get_group_pins(pctldev
, pin_group
,
1923 &pin_range
->range
.pins
,
1924 &pin_range
->range
.npins
);
1930 pinctrl_add_gpio_range(pctldev
, &pin_range
->range
);
1932 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1933 gpio_offset
, gpio_offset
+ pin_range
->range
.npins
- 1,
1934 pinctrl_dev_get_devname(pctldev
), pin_group
);
1936 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1940 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range
);
1943 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1944 * @chip: the gpiochip to add the range for
1945 * @pinctrl_name: the dev_name() of the pin controller to map to
1946 * @gpio_offset: the start offset in the current gpio_chip number space
1947 * @pin_offset: the start offset in the pin controller number space
1948 * @npins: the number of pins from the offset of each pin space (GPIO and
1949 * pin controller) to accumulate in this range
1951 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
1952 unsigned int gpio_offset
, unsigned int pin_offset
,
1955 struct gpio_pin_range
*pin_range
;
1956 struct gpio_device
*gdev
= chip
->gpiodev
;
1959 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1961 chip_err(chip
, "failed to allocate pin ranges\n");
1965 /* Use local offset as range ID */
1966 pin_range
->range
.id
= gpio_offset
;
1967 pin_range
->range
.gc
= chip
;
1968 pin_range
->range
.name
= chip
->label
;
1969 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1970 pin_range
->range
.pin_base
= pin_offset
;
1971 pin_range
->range
.npins
= npins
;
1972 pin_range
->pctldev
= pinctrl_find_and_add_gpio_range(pinctl_name
,
1974 if (IS_ERR(pin_range
->pctldev
)) {
1975 ret
= PTR_ERR(pin_range
->pctldev
);
1976 chip_err(chip
, "could not create pin range\n");
1980 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1981 gpio_offset
, gpio_offset
+ npins
- 1,
1983 pin_offset
, pin_offset
+ npins
- 1);
1985 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1989 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range
);
1992 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1993 * @chip: the chip to remove all the mappings for
1995 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
1997 struct gpio_pin_range
*pin_range
, *tmp
;
1998 struct gpio_device
*gdev
= chip
->gpiodev
;
2000 list_for_each_entry_safe(pin_range
, tmp
, &gdev
->pin_ranges
, node
) {
2001 list_del(&pin_range
->node
);
2002 pinctrl_remove_gpio_range(pin_range
->pctldev
,
2007 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges
);
2009 #endif /* CONFIG_PINCTRL */
2011 /* These "optional" allocation calls help prevent drivers from stomping
2012 * on each other, and help provide better diagnostics in debugfs.
2013 * They're called even less than the "set direction" calls.
2015 static int __gpiod_request(struct gpio_desc
*desc
, const char *label
)
2017 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2019 unsigned long flags
;
2021 spin_lock_irqsave(&gpio_lock
, flags
);
2023 /* NOTE: gpio_request() can be called in early boot,
2024 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2027 if (test_and_set_bit(FLAG_REQUESTED
, &desc
->flags
) == 0) {
2028 desc_set_label(desc
, label
? : "?");
2035 if (chip
->request
) {
2036 /* chip->request may sleep */
2037 spin_unlock_irqrestore(&gpio_lock
, flags
);
2038 status
= chip
->request(chip
, gpio_chip_hwgpio(desc
));
2039 spin_lock_irqsave(&gpio_lock
, flags
);
2042 desc_set_label(desc
, NULL
);
2043 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
2047 if (chip
->get_direction
) {
2048 /* chip->get_direction may sleep */
2049 spin_unlock_irqrestore(&gpio_lock
, flags
);
2050 gpiod_get_direction(desc
);
2051 spin_lock_irqsave(&gpio_lock
, flags
);
2054 spin_unlock_irqrestore(&gpio_lock
, flags
);
2059 * This descriptor validation needs to be inserted verbatim into each
2060 * function taking a descriptor, so we need to use a preprocessor
2061 * macro to avoid endless duplication. If the desc is NULL it is an
2062 * optional GPIO and calls should just bail out.
2064 #define VALIDATE_DESC(desc) do { \
2067 if (IS_ERR(desc)) { \
2068 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2069 return PTR_ERR(desc); \
2071 if (!desc->gdev) { \
2072 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2075 if ( !desc->gdev->chip ) { \
2076 dev_warn(&desc->gdev->dev, \
2077 "%s: backing chip is gone\n", __func__); \
2081 #define VALIDATE_DESC_VOID(desc) do { \
2084 if (IS_ERR(desc)) { \
2085 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2088 if (!desc->gdev) { \
2089 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2092 if (!desc->gdev->chip) { \
2093 dev_warn(&desc->gdev->dev, \
2094 "%s: backing chip is gone\n", __func__); \
2099 int gpiod_request(struct gpio_desc
*desc
, const char *label
)
2101 int status
= -EPROBE_DEFER
;
2102 struct gpio_device
*gdev
;
2104 VALIDATE_DESC(desc
);
2107 if (try_module_get(gdev
->owner
)) {
2108 status
= __gpiod_request(desc
, label
);
2110 module_put(gdev
->owner
);
2112 get_device(&gdev
->dev
);
2116 gpiod_dbg(desc
, "%s: status %d\n", __func__
, status
);
2121 static bool __gpiod_free(struct gpio_desc
*desc
)
2124 unsigned long flags
;
2125 struct gpio_chip
*chip
;
2129 gpiod_unexport(desc
);
2131 spin_lock_irqsave(&gpio_lock
, flags
);
2133 chip
= desc
->gdev
->chip
;
2134 if (chip
&& test_bit(FLAG_REQUESTED
, &desc
->flags
)) {
2136 spin_unlock_irqrestore(&gpio_lock
, flags
);
2137 might_sleep_if(chip
->can_sleep
);
2138 chip
->free(chip
, gpio_chip_hwgpio(desc
));
2139 spin_lock_irqsave(&gpio_lock
, flags
);
2141 desc_set_label(desc
, NULL
);
2142 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2143 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
2144 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2145 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2146 clear_bit(FLAG_IS_HOGGED
, &desc
->flags
);
2150 spin_unlock_irqrestore(&gpio_lock
, flags
);
2154 void gpiod_free(struct gpio_desc
*desc
)
2156 if (desc
&& desc
->gdev
&& __gpiod_free(desc
)) {
2157 module_put(desc
->gdev
->owner
);
2158 put_device(&desc
->gdev
->dev
);
2160 WARN_ON(extra_checks
);
2165 * gpiochip_is_requested - return string iff signal was requested
2166 * @chip: controller managing the signal
2167 * @offset: of signal within controller's 0..(ngpio - 1) range
2169 * Returns NULL if the GPIO is not currently requested, else a string.
2170 * The string returned is the label passed to gpio_request(); if none has been
2171 * passed it is a meaningless, non-NULL constant.
2173 * This function is for use by GPIO controller drivers. The label can
2174 * help with diagnostics, and knowing that the signal is used as a GPIO
2175 * can help avoid accidentally multiplexing it to another controller.
2177 const char *gpiochip_is_requested(struct gpio_chip
*chip
, unsigned offset
)
2179 struct gpio_desc
*desc
;
2181 if (offset
>= chip
->ngpio
)
2184 desc
= &chip
->gpiodev
->descs
[offset
];
2186 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) == 0)
2190 EXPORT_SYMBOL_GPL(gpiochip_is_requested
);
2193 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2194 * @desc: GPIO descriptor to request
2195 * @label: label for the GPIO
2197 * Function allows GPIO chip drivers to request and use their own GPIO
2198 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2199 * function will not increase reference count of the GPIO chip module. This
2200 * allows the GPIO chip module to be unloaded as needed (we assume that the
2201 * GPIO chip driver handles freeing the GPIOs it has requested).
2203 struct gpio_desc
*gpiochip_request_own_desc(struct gpio_chip
*chip
, u16 hwnum
,
2206 struct gpio_desc
*desc
= gpiochip_get_desc(chip
, hwnum
);
2210 chip_err(chip
, "failed to get GPIO descriptor\n");
2214 err
= __gpiod_request(desc
, label
);
2216 return ERR_PTR(err
);
2220 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc
);
2223 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2224 * @desc: GPIO descriptor to free
2226 * Function frees the given GPIO requested previously with
2227 * gpiochip_request_own_desc().
2229 void gpiochip_free_own_desc(struct gpio_desc
*desc
)
2234 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc
);
2237 * Drivers MUST set GPIO direction before making get/set calls. In
2238 * some cases this is done in early boot, before IRQs are enabled.
2240 * As a rule these aren't called more than once (except for drivers
2241 * using the open-drain emulation idiom) so these are natural places
2242 * to accumulate extra debugging checks. Note that we can't (yet)
2243 * rely on gpio_request() having been called beforehand.
2247 * gpiod_direction_input - set the GPIO direction to input
2248 * @desc: GPIO to set to input
2250 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2251 * be called safely on it.
2253 * Return 0 in case of success, else an error code.
2255 int gpiod_direction_input(struct gpio_desc
*desc
)
2257 struct gpio_chip
*chip
;
2258 int status
= -EINVAL
;
2260 VALIDATE_DESC(desc
);
2261 chip
= desc
->gdev
->chip
;
2263 if (!chip
->get
|| !chip
->direction_input
) {
2265 "%s: missing get() or direction_input() operations\n",
2270 status
= chip
->direction_input(chip
, gpio_chip_hwgpio(desc
));
2272 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2274 trace_gpio_direction(desc_to_gpio(desc
), 1, status
);
2278 EXPORT_SYMBOL_GPL(gpiod_direction_input
);
2280 static int gpio_set_drive_single_ended(struct gpio_chip
*gc
, unsigned offset
,
2281 enum pin_config_param mode
)
2283 unsigned long config
= { PIN_CONF_PACKED(mode
, 0) };
2285 return gc
->set_config
? gc
->set_config(gc
, offset
, config
) : -ENOTSUPP
;
2288 static int _gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
2290 struct gpio_chip
*gc
= desc
->gdev
->chip
;
2294 /* GPIOs used for IRQs shall not be set as output */
2295 if (test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
)) {
2297 "%s: tried to set a GPIO tied to an IRQ as output\n",
2302 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
2303 /* First see if we can enable open drain in hardware */
2304 ret
= gpio_set_drive_single_ended(gc
, gpio_chip_hwgpio(desc
),
2305 PIN_CONFIG_DRIVE_OPEN_DRAIN
);
2307 goto set_output_value
;
2308 /* Emulate open drain by not actively driving the line high */
2310 return gpiod_direction_input(desc
);
2312 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
2313 ret
= gpio_set_drive_single_ended(gc
, gpio_chip_hwgpio(desc
),
2314 PIN_CONFIG_DRIVE_OPEN_SOURCE
);
2316 goto set_output_value
;
2317 /* Emulate open source by not actively driving the line low */
2319 return gpiod_direction_input(desc
);
2321 gpio_set_drive_single_ended(gc
, gpio_chip_hwgpio(desc
),
2322 PIN_CONFIG_DRIVE_PUSH_PULL
);
2326 if (!gc
->set
|| !gc
->direction_output
) {
2328 "%s: missing set() or direction_output() operations\n",
2333 ret
= gc
->direction_output(gc
, gpio_chip_hwgpio(desc
), val
);
2335 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2336 trace_gpio_value(desc_to_gpio(desc
), 0, val
);
2337 trace_gpio_direction(desc_to_gpio(desc
), 0, ret
);
2342 * gpiod_direction_output_raw - set the GPIO direction to output
2343 * @desc: GPIO to set to output
2344 * @value: initial output value of the GPIO
2346 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2347 * be called safely on it. The initial value of the output must be specified
2348 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2350 * Return 0 in case of success, else an error code.
2352 int gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
2354 VALIDATE_DESC(desc
);
2355 return _gpiod_direction_output_raw(desc
, value
);
2357 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw
);
2360 * gpiod_direction_output - set the GPIO direction to output
2361 * @desc: GPIO to set to output
2362 * @value: initial output value of the GPIO
2364 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2365 * be called safely on it. The initial value of the output must be specified
2366 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2369 * Return 0 in case of success, else an error code.
2371 int gpiod_direction_output(struct gpio_desc
*desc
, int value
)
2373 VALIDATE_DESC(desc
);
2374 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2378 return _gpiod_direction_output_raw(desc
, value
);
2380 EXPORT_SYMBOL_GPL(gpiod_direction_output
);
2383 * gpiod_set_debounce - sets @debounce time for a @gpio
2384 * @gpio: the gpio to set debounce time
2385 * @debounce: debounce time is microseconds
2387 * returns -ENOTSUPP if the controller does not support setting
2390 int gpiod_set_debounce(struct gpio_desc
*desc
, unsigned debounce
)
2392 struct gpio_chip
*chip
;
2393 unsigned long config
;
2395 VALIDATE_DESC(desc
);
2396 chip
= desc
->gdev
->chip
;
2397 if (!chip
->set
|| !chip
->set_config
) {
2399 "%s: missing set() or set_config() operations\n",
2404 config
= pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE
, debounce
);
2405 return chip
->set_config(chip
, gpio_chip_hwgpio(desc
), config
);
2407 EXPORT_SYMBOL_GPL(gpiod_set_debounce
);
2410 * gpiod_is_active_low - test whether a GPIO is active-low or not
2411 * @desc: the gpio descriptor to test
2413 * Returns 1 if the GPIO is active-low, 0 otherwise.
2415 int gpiod_is_active_low(const struct gpio_desc
*desc
)
2417 VALIDATE_DESC(desc
);
2418 return test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2420 EXPORT_SYMBOL_GPL(gpiod_is_active_low
);
2422 /* I/O calls are only valid after configuration completed; the relevant
2423 * "is this a valid GPIO" error checks should already have been done.
2425 * "Get" operations are often inlinable as reading a pin value register,
2426 * and masking the relevant bit in that register.
2428 * When "set" operations are inlinable, they involve writing that mask to
2429 * one register to set a low value, or a different register to set it high.
2430 * Otherwise locking is needed, so there may be little value to inlining.
2432 *------------------------------------------------------------------------
2434 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2435 * have requested the GPIO. That can include implicit requesting by
2436 * a direction setting call. Marking a gpio as requested locks its chip
2437 * in memory, guaranteeing that these table lookups need no more locking
2438 * and that gpiochip_remove() will fail.
2440 * REVISIT when debugging, consider adding some instrumentation to ensure
2441 * that the GPIO was actually requested.
2444 static int _gpiod_get_raw_value(const struct gpio_desc
*desc
)
2446 struct gpio_chip
*chip
;
2450 chip
= desc
->gdev
->chip
;
2451 offset
= gpio_chip_hwgpio(desc
);
2452 value
= chip
->get
? chip
->get(chip
, offset
) : -EIO
;
2453 value
= value
< 0 ? value
: !!value
;
2454 trace_gpio_value(desc_to_gpio(desc
), 1, value
);
2459 * gpiod_get_raw_value() - return a gpio's raw value
2460 * @desc: gpio whose value will be returned
2462 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2463 * its ACTIVE_LOW status, or negative errno on failure.
2465 * This function should be called from contexts where we cannot sleep, and will
2466 * complain if the GPIO chip functions potentially sleep.
2468 int gpiod_get_raw_value(const struct gpio_desc
*desc
)
2470 VALIDATE_DESC(desc
);
2471 /* Should be using gpio_get_value_cansleep() */
2472 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2473 return _gpiod_get_raw_value(desc
);
2475 EXPORT_SYMBOL_GPL(gpiod_get_raw_value
);
2478 * gpiod_get_value() - return a gpio's value
2479 * @desc: gpio whose value will be returned
2481 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2482 * account, or negative errno on failure.
2484 * This function should be called from contexts where we cannot sleep, and will
2485 * complain if the GPIO chip functions potentially sleep.
2487 int gpiod_get_value(const struct gpio_desc
*desc
)
2491 VALIDATE_DESC(desc
);
2492 /* Should be using gpio_get_value_cansleep() */
2493 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2495 value
= _gpiod_get_raw_value(desc
);
2499 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2504 EXPORT_SYMBOL_GPL(gpiod_get_value
);
2507 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2508 * @desc: gpio descriptor whose state need to be set.
2509 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2511 static void _gpio_set_open_drain_value(struct gpio_desc
*desc
, bool value
)
2514 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2515 int offset
= gpio_chip_hwgpio(desc
);
2518 err
= chip
->direction_input(chip
, offset
);
2520 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2522 err
= chip
->direction_output(chip
, offset
, 0);
2524 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2526 trace_gpio_direction(desc_to_gpio(desc
), value
, err
);
2529 "%s: Error in set_value for open drain err %d\n",
2534 * _gpio_set_open_source_value() - Set the open source gpio's value.
2535 * @desc: gpio descriptor whose state need to be set.
2536 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2538 static void _gpio_set_open_source_value(struct gpio_desc
*desc
, bool value
)
2541 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2542 int offset
= gpio_chip_hwgpio(desc
);
2545 err
= chip
->direction_output(chip
, offset
, 1);
2547 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2549 err
= chip
->direction_input(chip
, offset
);
2551 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2553 trace_gpio_direction(desc_to_gpio(desc
), !value
, err
);
2556 "%s: Error in set_value for open source err %d\n",
2560 static void _gpiod_set_raw_value(struct gpio_desc
*desc
, bool value
)
2562 struct gpio_chip
*chip
;
2564 chip
= desc
->gdev
->chip
;
2565 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
2566 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
2567 _gpio_set_open_drain_value(desc
, value
);
2568 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
2569 _gpio_set_open_source_value(desc
, value
);
2571 chip
->set(chip
, gpio_chip_hwgpio(desc
), value
);
2575 * set multiple outputs on the same chip;
2576 * use the chip's set_multiple function if available;
2577 * otherwise set the outputs sequentially;
2578 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2579 * defines which outputs are to be changed
2580 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2581 * defines the values the outputs specified by mask are to be set to
2583 static void gpio_chip_set_multiple(struct gpio_chip
*chip
,
2584 unsigned long *mask
, unsigned long *bits
)
2586 if (chip
->set_multiple
) {
2587 chip
->set_multiple(chip
, mask
, bits
);
2590 for (i
= 0; i
< chip
->ngpio
; i
++) {
2591 if (mask
[BIT_WORD(i
)] == 0) {
2592 /* no more set bits in this mask word;
2593 * skip ahead to the next word */
2594 i
= (BIT_WORD(i
) + 1) * BITS_PER_LONG
- 1;
2597 /* set outputs if the corresponding mask bit is set */
2598 if (__test_and_clear_bit(i
, mask
))
2599 chip
->set(chip
, i
, test_bit(i
, bits
));
2604 void gpiod_set_array_value_complex(bool raw
, bool can_sleep
,
2605 unsigned int array_size
,
2606 struct gpio_desc
**desc_array
,
2611 while (i
< array_size
) {
2612 struct gpio_chip
*chip
= desc_array
[i
]->gdev
->chip
;
2613 unsigned long mask
[BITS_TO_LONGS(chip
->ngpio
)];
2614 unsigned long bits
[BITS_TO_LONGS(chip
->ngpio
)];
2618 WARN_ON(chip
->can_sleep
);
2620 memset(mask
, 0, sizeof(mask
));
2622 struct gpio_desc
*desc
= desc_array
[i
];
2623 int hwgpio
= gpio_chip_hwgpio(desc
);
2624 int value
= value_array
[i
];
2626 if (!raw
&& test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2628 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
2630 * collect all normal outputs belonging to the same chip
2631 * open drain and open source outputs are set individually
2633 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
2634 _gpio_set_open_drain_value(desc
, value
);
2635 } else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
2636 _gpio_set_open_source_value(desc
, value
);
2638 __set_bit(hwgpio
, mask
);
2640 __set_bit(hwgpio
, bits
);
2642 __clear_bit(hwgpio
, bits
);
2646 } while ((i
< array_size
) &&
2647 (desc_array
[i
]->gdev
->chip
== chip
));
2648 /* push collected bits to outputs */
2650 gpio_chip_set_multiple(chip
, mask
, bits
);
2655 * gpiod_set_raw_value() - assign a gpio's raw value
2656 * @desc: gpio whose value will be assigned
2657 * @value: value to assign
2659 * Set the raw value of the GPIO, i.e. the value of its physical line without
2660 * regard for its ACTIVE_LOW status.
2662 * This function should be called from contexts where we cannot sleep, and will
2663 * complain if the GPIO chip functions potentially sleep.
2665 void gpiod_set_raw_value(struct gpio_desc
*desc
, int value
)
2667 VALIDATE_DESC_VOID(desc
);
2668 /* Should be using gpiod_set_value_cansleep() */
2669 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2670 _gpiod_set_raw_value(desc
, value
);
2672 EXPORT_SYMBOL_GPL(gpiod_set_raw_value
);
2675 * gpiod_set_value() - assign a gpio's value
2676 * @desc: gpio whose value will be assigned
2677 * @value: value to assign
2679 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2682 * This function should be called from contexts where we cannot sleep, and will
2683 * complain if the GPIO chip functions potentially sleep.
2685 void gpiod_set_value(struct gpio_desc
*desc
, int value
)
2687 VALIDATE_DESC_VOID(desc
);
2688 /* Should be using gpiod_set_value_cansleep() */
2689 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2690 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2692 _gpiod_set_raw_value(desc
, value
);
2694 EXPORT_SYMBOL_GPL(gpiod_set_value
);
2697 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2698 * @array_size: number of elements in the descriptor / value arrays
2699 * @desc_array: array of GPIO descriptors whose values will be assigned
2700 * @value_array: array of values to assign
2702 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2703 * without regard for their ACTIVE_LOW status.
2705 * This function should be called from contexts where we cannot sleep, and will
2706 * complain if the GPIO chip functions potentially sleep.
2708 void gpiod_set_raw_array_value(unsigned int array_size
,
2709 struct gpio_desc
**desc_array
, int *value_array
)
2713 gpiod_set_array_value_complex(true, false, array_size
, desc_array
,
2716 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value
);
2719 * gpiod_set_array_value() - assign values to an array of GPIOs
2720 * @array_size: number of elements in the descriptor / value arrays
2721 * @desc_array: array of GPIO descriptors whose values will be assigned
2722 * @value_array: array of values to assign
2724 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2727 * This function should be called from contexts where we cannot sleep, and will
2728 * complain if the GPIO chip functions potentially sleep.
2730 void gpiod_set_array_value(unsigned int array_size
,
2731 struct gpio_desc
**desc_array
, int *value_array
)
2735 gpiod_set_array_value_complex(false, false, array_size
, desc_array
,
2738 EXPORT_SYMBOL_GPL(gpiod_set_array_value
);
2741 * gpiod_cansleep() - report whether gpio value access may sleep
2742 * @desc: gpio to check
2745 int gpiod_cansleep(const struct gpio_desc
*desc
)
2747 VALIDATE_DESC(desc
);
2748 return desc
->gdev
->chip
->can_sleep
;
2750 EXPORT_SYMBOL_GPL(gpiod_cansleep
);
2753 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2754 * @desc: gpio whose IRQ will be returned (already requested)
2756 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2759 int gpiod_to_irq(const struct gpio_desc
*desc
)
2761 struct gpio_chip
*chip
;
2765 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2766 * requires this function to not return zero on an invalid descriptor
2767 * but rather a negative error number.
2769 if (!desc
|| IS_ERR(desc
) || !desc
->gdev
|| !desc
->gdev
->chip
)
2772 chip
= desc
->gdev
->chip
;
2773 offset
= gpio_chip_hwgpio(desc
);
2775 int retirq
= chip
->to_irq(chip
, offset
);
2777 /* Zero means NO_IRQ */
2785 EXPORT_SYMBOL_GPL(gpiod_to_irq
);
2788 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2789 * @chip: the chip the GPIO to lock belongs to
2790 * @offset: the offset of the GPIO to lock as IRQ
2792 * This is used directly by GPIO drivers that want to lock down
2793 * a certain GPIO line to be used for IRQs.
2795 int gpiochip_lock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2797 struct gpio_desc
*desc
;
2799 desc
= gpiochip_get_desc(chip
, offset
);
2801 return PTR_ERR(desc
);
2804 * If it's fast: flush the direction setting if something changed
2807 if (!chip
->can_sleep
&& chip
->get_direction
) {
2808 int dir
= chip
->get_direction(chip
, offset
);
2811 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2813 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2816 if (test_bit(FLAG_IS_OUT
, &desc
->flags
)) {
2818 "%s: tried to flag a GPIO set as output for IRQ\n",
2823 set_bit(FLAG_USED_AS_IRQ
, &desc
->flags
);
2826 * If the consumer has not set up a label (such as when the
2827 * IRQ is referenced from .to_irq()) we set up a label here
2828 * so it is clear this is used as an interrupt.
2831 desc_set_label(desc
, "interrupt");
2835 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq
);
2838 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2839 * @chip: the chip the GPIO to lock belongs to
2840 * @offset: the offset of the GPIO to lock as IRQ
2842 * This is used directly by GPIO drivers that want to indicate
2843 * that a certain GPIO is no longer used exclusively for IRQ.
2845 void gpiochip_unlock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2847 struct gpio_desc
*desc
;
2849 desc
= gpiochip_get_desc(chip
, offset
);
2853 clear_bit(FLAG_USED_AS_IRQ
, &desc
->flags
);
2855 /* If we only had this marking, erase it */
2856 if (desc
->label
&& !strcmp(desc
->label
, "interrupt"))
2857 desc_set_label(desc
, NULL
);
2859 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq
);
2861 bool gpiochip_line_is_irq(struct gpio_chip
*chip
, unsigned int offset
)
2863 if (offset
>= chip
->ngpio
)
2866 return test_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2868 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq
);
2870 bool gpiochip_line_is_open_drain(struct gpio_chip
*chip
, unsigned int offset
)
2872 if (offset
>= chip
->ngpio
)
2875 return test_bit(FLAG_OPEN_DRAIN
, &chip
->gpiodev
->descs
[offset
].flags
);
2877 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain
);
2879 bool gpiochip_line_is_open_source(struct gpio_chip
*chip
, unsigned int offset
)
2881 if (offset
>= chip
->ngpio
)
2884 return test_bit(FLAG_OPEN_SOURCE
, &chip
->gpiodev
->descs
[offset
].flags
);
2886 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source
);
2889 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2890 * @desc: gpio whose value will be returned
2892 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2893 * its ACTIVE_LOW status, or negative errno on failure.
2895 * This function is to be called from contexts that can sleep.
2897 int gpiod_get_raw_value_cansleep(const struct gpio_desc
*desc
)
2899 might_sleep_if(extra_checks
);
2900 VALIDATE_DESC(desc
);
2901 return _gpiod_get_raw_value(desc
);
2903 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep
);
2906 * gpiod_get_value_cansleep() - return a gpio's value
2907 * @desc: gpio whose value will be returned
2909 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2910 * account, or negative errno on failure.
2912 * This function is to be called from contexts that can sleep.
2914 int gpiod_get_value_cansleep(const struct gpio_desc
*desc
)
2918 might_sleep_if(extra_checks
);
2919 VALIDATE_DESC(desc
);
2920 value
= _gpiod_get_raw_value(desc
);
2924 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2929 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep
);
2932 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2933 * @desc: gpio whose value will be assigned
2934 * @value: value to assign
2936 * Set the raw value of the GPIO, i.e. the value of its physical line without
2937 * regard for its ACTIVE_LOW status.
2939 * This function is to be called from contexts that can sleep.
2941 void gpiod_set_raw_value_cansleep(struct gpio_desc
*desc
, int value
)
2943 might_sleep_if(extra_checks
);
2944 VALIDATE_DESC_VOID(desc
);
2945 _gpiod_set_raw_value(desc
, value
);
2947 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep
);
2950 * gpiod_set_value_cansleep() - assign a gpio's value
2951 * @desc: gpio whose value will be assigned
2952 * @value: value to assign
2954 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2957 * This function is to be called from contexts that can sleep.
2959 void gpiod_set_value_cansleep(struct gpio_desc
*desc
, int value
)
2961 might_sleep_if(extra_checks
);
2962 VALIDATE_DESC_VOID(desc
);
2963 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2965 _gpiod_set_raw_value(desc
, value
);
2967 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep
);
2970 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2971 * @array_size: number of elements in the descriptor / value arrays
2972 * @desc_array: array of GPIO descriptors whose values will be assigned
2973 * @value_array: array of values to assign
2975 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2976 * without regard for their ACTIVE_LOW status.
2978 * This function is to be called from contexts that can sleep.
2980 void gpiod_set_raw_array_value_cansleep(unsigned int array_size
,
2981 struct gpio_desc
**desc_array
,
2984 might_sleep_if(extra_checks
);
2987 gpiod_set_array_value_complex(true, true, array_size
, desc_array
,
2990 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep
);
2993 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2994 * @array_size: number of elements in the descriptor / value arrays
2995 * @desc_array: array of GPIO descriptors whose values will be assigned
2996 * @value_array: array of values to assign
2998 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3001 * This function is to be called from contexts that can sleep.
3003 void gpiod_set_array_value_cansleep(unsigned int array_size
,
3004 struct gpio_desc
**desc_array
,
3007 might_sleep_if(extra_checks
);
3010 gpiod_set_array_value_complex(false, true, array_size
, desc_array
,
3013 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep
);
3016 * gpiod_add_lookup_table() - register GPIO device consumers
3017 * @table: table of consumers to register
3019 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
)
3021 mutex_lock(&gpio_lookup_lock
);
3023 list_add_tail(&table
->list
, &gpio_lookup_list
);
3025 mutex_unlock(&gpio_lookup_lock
);
3029 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3030 * @table: table of consumers to unregister
3032 void gpiod_remove_lookup_table(struct gpiod_lookup_table
*table
)
3034 mutex_lock(&gpio_lookup_lock
);
3036 list_del(&table
->list
);
3038 mutex_unlock(&gpio_lookup_lock
);
3041 static struct gpiod_lookup_table
*gpiod_find_lookup_table(struct device
*dev
)
3043 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
3044 struct gpiod_lookup_table
*table
;
3046 mutex_lock(&gpio_lookup_lock
);
3048 list_for_each_entry(table
, &gpio_lookup_list
, list
) {
3049 if (table
->dev_id
&& dev_id
) {
3051 * Valid strings on both ends, must be identical to have
3054 if (!strcmp(table
->dev_id
, dev_id
))
3058 * One of the pointers is NULL, so both must be to have
3061 if (dev_id
== table
->dev_id
)
3068 mutex_unlock(&gpio_lookup_lock
);
3072 static struct gpio_desc
*gpiod_find(struct device
*dev
, const char *con_id
,
3074 enum gpio_lookup_flags
*flags
)
3076 struct gpio_desc
*desc
= ERR_PTR(-ENOENT
);
3077 struct gpiod_lookup_table
*table
;
3078 struct gpiod_lookup
*p
;
3080 table
= gpiod_find_lookup_table(dev
);
3084 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
3085 struct gpio_chip
*chip
;
3087 /* idx must always match exactly */
3091 /* If the lookup entry has a con_id, require exact match */
3092 if (p
->con_id
&& (!con_id
|| strcmp(p
->con_id
, con_id
)))
3095 chip
= find_chip_by_name(p
->chip_label
);
3098 dev_err(dev
, "cannot find GPIO chip %s\n",
3100 return ERR_PTR(-ENODEV
);
3103 if (chip
->ngpio
<= p
->chip_hwnum
) {
3105 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3106 idx
, chip
->ngpio
, chip
->label
);
3107 return ERR_PTR(-EINVAL
);
3110 desc
= gpiochip_get_desc(chip
, p
->chip_hwnum
);
3119 static int dt_gpio_count(struct device
*dev
, const char *con_id
)
3125 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
3127 snprintf(propname
, sizeof(propname
), "%s-%s",
3128 con_id
, gpio_suffixes
[i
]);
3130 snprintf(propname
, sizeof(propname
), "%s",
3133 ret
= of_gpio_named_count(dev
->of_node
, propname
);
3140 static int platform_gpio_count(struct device
*dev
, const char *con_id
)
3142 struct gpiod_lookup_table
*table
;
3143 struct gpiod_lookup
*p
;
3144 unsigned int count
= 0;
3146 table
= gpiod_find_lookup_table(dev
);
3150 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
3151 if ((con_id
&& p
->con_id
&& !strcmp(con_id
, p
->con_id
)) ||
3152 (!con_id
&& !p
->con_id
))
3162 * gpiod_count - return the number of GPIOs associated with a device / function
3163 * or -ENOENT if no GPIO has been assigned to the requested function
3164 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3165 * @con_id: function within the GPIO consumer
3167 int gpiod_count(struct device
*dev
, const char *con_id
)
3169 int count
= -ENOENT
;
3171 if (IS_ENABLED(CONFIG_OF
) && dev
&& dev
->of_node
)
3172 count
= dt_gpio_count(dev
, con_id
);
3173 else if (IS_ENABLED(CONFIG_ACPI
) && dev
&& ACPI_HANDLE(dev
))
3174 count
= acpi_gpio_count(dev
, con_id
);
3177 count
= platform_gpio_count(dev
, con_id
);
3181 EXPORT_SYMBOL_GPL(gpiod_count
);
3184 * gpiod_get - obtain a GPIO for a given GPIO function
3185 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3186 * @con_id: function within the GPIO consumer
3187 * @flags: optional GPIO initialization flags
3189 * Return the GPIO descriptor corresponding to the function con_id of device
3190 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3191 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3193 struct gpio_desc
*__must_check
gpiod_get(struct device
*dev
, const char *con_id
,
3194 enum gpiod_flags flags
)
3196 return gpiod_get_index(dev
, con_id
, 0, flags
);
3198 EXPORT_SYMBOL_GPL(gpiod_get
);
3201 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3202 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3203 * @con_id: function within the GPIO consumer
3204 * @flags: optional GPIO initialization flags
3206 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3207 * the requested function it will return NULL. This is convenient for drivers
3208 * that need to handle optional GPIOs.
3210 struct gpio_desc
*__must_check
gpiod_get_optional(struct device
*dev
,
3212 enum gpiod_flags flags
)
3214 return gpiod_get_index_optional(dev
, con_id
, 0, flags
);
3216 EXPORT_SYMBOL_GPL(gpiod_get_optional
);
3220 * gpiod_configure_flags - helper function to configure a given GPIO
3221 * @desc: gpio whose value will be assigned
3222 * @con_id: function within the GPIO consumer
3223 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3225 * @dflags: gpiod_flags - optional GPIO initialization flags
3227 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3228 * requested function and/or index, or another IS_ERR() code if an error
3229 * occurred while trying to acquire the GPIO.
3231 static int gpiod_configure_flags(struct gpio_desc
*desc
, const char *con_id
,
3232 unsigned long lflags
, enum gpiod_flags dflags
)
3236 if (lflags
& GPIO_ACTIVE_LOW
)
3237 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
3238 if (lflags
& GPIO_OPEN_DRAIN
)
3239 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
3240 if (lflags
& GPIO_OPEN_SOURCE
)
3241 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
3243 /* No particular flag request, return here... */
3244 if (!(dflags
& GPIOD_FLAGS_BIT_DIR_SET
)) {
3245 pr_debug("no flags found for %s\n", con_id
);
3250 if (dflags
& GPIOD_FLAGS_BIT_DIR_OUT
)
3251 status
= gpiod_direction_output(desc
,
3252 !!(dflags
& GPIOD_FLAGS_BIT_DIR_VAL
));
3254 status
= gpiod_direction_input(desc
);
3260 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3261 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3262 * @con_id: function within the GPIO consumer
3263 * @idx: index of the GPIO to obtain in the consumer
3264 * @flags: optional GPIO initialization flags
3266 * This variant of gpiod_get() allows to access GPIOs other than the first
3267 * defined one for functions that define several GPIOs.
3269 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3270 * requested function and/or index, or another IS_ERR() code if an error
3271 * occurred while trying to acquire the GPIO.
3273 struct gpio_desc
*__must_check
gpiod_get_index(struct device
*dev
,
3276 enum gpiod_flags flags
)
3278 struct gpio_desc
*desc
= NULL
;
3280 enum gpio_lookup_flags lookupflags
= 0;
3282 dev_dbg(dev
, "GPIO lookup for consumer %s\n", con_id
);
3285 /* Using device tree? */
3286 if (IS_ENABLED(CONFIG_OF
) && dev
->of_node
) {
3287 dev_dbg(dev
, "using device tree for GPIO lookup\n");
3288 desc
= of_find_gpio(dev
, con_id
, idx
, &lookupflags
);
3289 } else if (ACPI_COMPANION(dev
)) {
3290 dev_dbg(dev
, "using ACPI for GPIO lookup\n");
3291 desc
= acpi_find_gpio(dev
, con_id
, idx
, flags
, &lookupflags
);
3296 * Either we are not using DT or ACPI, or their lookup did not return
3297 * a result. In that case, use platform lookup as a fallback.
3299 if (!desc
|| desc
== ERR_PTR(-ENOENT
)) {
3300 dev_dbg(dev
, "using lookup tables for GPIO lookup\n");
3301 desc
= gpiod_find(dev
, con_id
, idx
, &lookupflags
);
3305 dev_dbg(dev
, "lookup for GPIO %s failed\n", con_id
);
3309 status
= gpiod_request(desc
, con_id
);
3311 return ERR_PTR(status
);
3313 status
= gpiod_configure_flags(desc
, con_id
, lookupflags
, flags
);
3315 dev_dbg(dev
, "setup of GPIO %s failed\n", con_id
);
3317 return ERR_PTR(status
);
3322 EXPORT_SYMBOL_GPL(gpiod_get_index
);
3325 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3326 * @fwnode: handle of the firmware node
3327 * @propname: name of the firmware property representing the GPIO
3329 * This function can be used for drivers that get their configuration
3332 * Function properly finds the corresponding GPIO using whatever is the
3333 * underlying firmware interface and then makes sure that the GPIO
3334 * descriptor is requested before it is returned to the caller.
3336 * In case of error an ERR_PTR() is returned.
3338 struct gpio_desc
*fwnode_get_named_gpiod(struct fwnode_handle
*fwnode
,
3339 const char *propname
)
3341 struct gpio_desc
*desc
= ERR_PTR(-ENODEV
);
3342 bool active_low
= false;
3343 bool single_ended
= false;
3347 return ERR_PTR(-EINVAL
);
3349 if (is_of_node(fwnode
)) {
3350 enum of_gpio_flags flags
;
3352 desc
= of_get_named_gpiod_flags(to_of_node(fwnode
), propname
, 0,
3354 if (!IS_ERR(desc
)) {
3355 active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
3356 single_ended
= flags
& OF_GPIO_SINGLE_ENDED
;
3358 } else if (is_acpi_node(fwnode
)) {
3359 struct acpi_gpio_info info
;
3361 desc
= acpi_node_get_gpiod(fwnode
, propname
, 0, &info
);
3363 active_low
= info
.polarity
== GPIO_ACTIVE_LOW
;
3369 ret
= gpiod_request(desc
, NULL
);
3371 return ERR_PTR(ret
);
3374 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
3378 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
3380 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
3385 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod
);
3388 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3390 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3391 * @con_id: function within the GPIO consumer
3392 * @index: index of the GPIO to obtain in the consumer
3393 * @flags: optional GPIO initialization flags
3395 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3396 * specified index was assigned to the requested function it will return NULL.
3397 * This is convenient for drivers that need to handle optional GPIOs.
3399 struct gpio_desc
*__must_check
gpiod_get_index_optional(struct device
*dev
,
3402 enum gpiod_flags flags
)
3404 struct gpio_desc
*desc
;
3406 desc
= gpiod_get_index(dev
, con_id
, index
, flags
);
3408 if (PTR_ERR(desc
) == -ENOENT
)
3414 EXPORT_SYMBOL_GPL(gpiod_get_index_optional
);
3417 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3418 * @desc: gpio whose value will be assigned
3419 * @name: gpio line name
3420 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3422 * @dflags: gpiod_flags - optional GPIO initialization flags
3424 int gpiod_hog(struct gpio_desc
*desc
, const char *name
,
3425 unsigned long lflags
, enum gpiod_flags dflags
)
3427 struct gpio_chip
*chip
;
3428 struct gpio_desc
*local_desc
;
3432 chip
= gpiod_to_chip(desc
);
3433 hwnum
= gpio_chip_hwgpio(desc
);
3435 local_desc
= gpiochip_request_own_desc(chip
, hwnum
, name
);
3436 if (IS_ERR(local_desc
)) {
3437 status
= PTR_ERR(local_desc
);
3438 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3439 name
, chip
->label
, hwnum
, status
);
3443 status
= gpiod_configure_flags(desc
, name
, lflags
, dflags
);
3445 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3446 name
, chip
->label
, hwnum
, status
);
3447 gpiochip_free_own_desc(desc
);
3451 /* Mark GPIO as hogged so it can be identified and removed later */
3452 set_bit(FLAG_IS_HOGGED
, &desc
->flags
);
3454 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3455 desc_to_gpio(desc
), name
,
3456 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ? "output" : "input",
3457 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ?
3458 (dflags
&GPIOD_FLAGS_BIT_DIR_VAL
) ? "/high" : "/low":"");
3464 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3465 * @chip: gpio chip to act on
3467 * This is only used by of_gpiochip_remove to free hogged gpios
3469 static void gpiochip_free_hogs(struct gpio_chip
*chip
)
3473 for (id
= 0; id
< chip
->ngpio
; id
++) {
3474 if (test_bit(FLAG_IS_HOGGED
, &chip
->gpiodev
->descs
[id
].flags
))
3475 gpiochip_free_own_desc(&chip
->gpiodev
->descs
[id
]);
3480 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3481 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3482 * @con_id: function within the GPIO consumer
3483 * @flags: optional GPIO initialization flags
3485 * This function acquires all the GPIOs defined under a given function.
3487 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3488 * no GPIO has been assigned to the requested function, or another IS_ERR()
3489 * code if an error occurred while trying to acquire the GPIOs.
3491 struct gpio_descs
*__must_check
gpiod_get_array(struct device
*dev
,
3493 enum gpiod_flags flags
)
3495 struct gpio_desc
*desc
;
3496 struct gpio_descs
*descs
;
3499 count
= gpiod_count(dev
, con_id
);
3501 return ERR_PTR(count
);
3503 descs
= kzalloc(sizeof(*descs
) + sizeof(descs
->desc
[0]) * count
,
3506 return ERR_PTR(-ENOMEM
);
3508 for (descs
->ndescs
= 0; descs
->ndescs
< count
; ) {
3509 desc
= gpiod_get_index(dev
, con_id
, descs
->ndescs
, flags
);
3511 gpiod_put_array(descs
);
3512 return ERR_CAST(desc
);
3514 descs
->desc
[descs
->ndescs
] = desc
;
3519 EXPORT_SYMBOL_GPL(gpiod_get_array
);
3522 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3524 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3525 * @con_id: function within the GPIO consumer
3526 * @flags: optional GPIO initialization flags
3528 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3529 * assigned to the requested function it will return NULL.
3531 struct gpio_descs
*__must_check
gpiod_get_array_optional(struct device
*dev
,
3533 enum gpiod_flags flags
)
3535 struct gpio_descs
*descs
;
3537 descs
= gpiod_get_array(dev
, con_id
, flags
);
3538 if (IS_ERR(descs
) && (PTR_ERR(descs
) == -ENOENT
))
3543 EXPORT_SYMBOL_GPL(gpiod_get_array_optional
);
3546 * gpiod_put - dispose of a GPIO descriptor
3547 * @desc: GPIO descriptor to dispose of
3549 * No descriptor can be used after gpiod_put() has been called on it.
3551 void gpiod_put(struct gpio_desc
*desc
)
3555 EXPORT_SYMBOL_GPL(gpiod_put
);
3558 * gpiod_put_array - dispose of multiple GPIO descriptors
3559 * @descs: struct gpio_descs containing an array of descriptors
3561 void gpiod_put_array(struct gpio_descs
*descs
)
3565 for (i
= 0; i
< descs
->ndescs
; i
++)
3566 gpiod_put(descs
->desc
[i
]);
3570 EXPORT_SYMBOL_GPL(gpiod_put_array
);
3572 static int __init
gpiolib_dev_init(void)
3576 /* Register GPIO sysfs bus */
3577 ret
= bus_register(&gpio_bus_type
);
3579 pr_err("gpiolib: could not register GPIO bus type\n");
3583 ret
= alloc_chrdev_region(&gpio_devt
, 0, GPIO_DEV_MAX
, "gpiochip");
3585 pr_err("gpiolib: failed to allocate char dev region\n");
3586 bus_unregister(&gpio_bus_type
);
3588 gpiolib_initialized
= true;
3589 gpiochip_setup_devs();
3593 core_initcall(gpiolib_dev_init
);
3595 #ifdef CONFIG_DEBUG_FS
3597 static void gpiolib_dbg_show(struct seq_file
*s
, struct gpio_device
*gdev
)
3600 struct gpio_chip
*chip
= gdev
->chip
;
3601 unsigned gpio
= gdev
->base
;
3602 struct gpio_desc
*gdesc
= &gdev
->descs
[0];
3606 for (i
= 0; i
< gdev
->ngpio
; i
++, gpio
++, gdesc
++) {
3607 if (!test_bit(FLAG_REQUESTED
, &gdesc
->flags
)) {
3609 seq_printf(s
, " gpio-%-3d (%-20.20s)\n",
3615 gpiod_get_direction(gdesc
);
3616 is_out
= test_bit(FLAG_IS_OUT
, &gdesc
->flags
);
3617 is_irq
= test_bit(FLAG_USED_AS_IRQ
, &gdesc
->flags
);
3618 seq_printf(s
, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3619 gpio
, gdesc
->name
? gdesc
->name
: "", gdesc
->label
,
3620 is_out
? "out" : "in ",
3622 ? (chip
->get(chip
, i
) ? "hi" : "lo")
3624 is_irq
? "IRQ" : " ");
3625 seq_printf(s
, "\n");
3629 static void *gpiolib_seq_start(struct seq_file
*s
, loff_t
*pos
)
3631 unsigned long flags
;
3632 struct gpio_device
*gdev
= NULL
;
3633 loff_t index
= *pos
;
3637 spin_lock_irqsave(&gpio_lock
, flags
);
3638 list_for_each_entry(gdev
, &gpio_devices
, list
)
3640 spin_unlock_irqrestore(&gpio_lock
, flags
);
3643 spin_unlock_irqrestore(&gpio_lock
, flags
);
3648 static void *gpiolib_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
3650 unsigned long flags
;
3651 struct gpio_device
*gdev
= v
;
3654 spin_lock_irqsave(&gpio_lock
, flags
);
3655 if (list_is_last(&gdev
->list
, &gpio_devices
))
3658 ret
= list_entry(gdev
->list
.next
, struct gpio_device
, list
);
3659 spin_unlock_irqrestore(&gpio_lock
, flags
);
3667 static void gpiolib_seq_stop(struct seq_file
*s
, void *v
)
3671 static int gpiolib_seq_show(struct seq_file
*s
, void *v
)
3673 struct gpio_device
*gdev
= v
;
3674 struct gpio_chip
*chip
= gdev
->chip
;
3675 struct device
*parent
;
3678 seq_printf(s
, "%s%s: (dangling chip)", (char *)s
->private,
3679 dev_name(&gdev
->dev
));
3683 seq_printf(s
, "%s%s: GPIOs %d-%d", (char *)s
->private,
3684 dev_name(&gdev
->dev
),
3685 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1);
3686 parent
= chip
->parent
;
3688 seq_printf(s
, ", parent: %s/%s",
3689 parent
->bus
? parent
->bus
->name
: "no-bus",
3692 seq_printf(s
, ", %s", chip
->label
);
3693 if (chip
->can_sleep
)
3694 seq_printf(s
, ", can sleep");
3695 seq_printf(s
, ":\n");
3698 chip
->dbg_show(s
, chip
);
3700 gpiolib_dbg_show(s
, gdev
);
3705 static const struct seq_operations gpiolib_seq_ops
= {
3706 .start
= gpiolib_seq_start
,
3707 .next
= gpiolib_seq_next
,
3708 .stop
= gpiolib_seq_stop
,
3709 .show
= gpiolib_seq_show
,
3712 static int gpiolib_open(struct inode
*inode
, struct file
*file
)
3714 return seq_open(file
, &gpiolib_seq_ops
);
3717 static const struct file_operations gpiolib_operations
= {
3718 .owner
= THIS_MODULE
,
3719 .open
= gpiolib_open
,
3721 .llseek
= seq_lseek
,
3722 .release
= seq_release
,
3725 static int __init
gpiolib_debugfs_init(void)
3727 /* /sys/kernel/debug/gpio */
3728 (void) debugfs_create_file("gpio", S_IFREG
| S_IRUGO
,
3729 NULL
, NULL
, &gpiolib_operations
);
3732 subsys_initcall(gpiolib_debugfs_init
);
3734 #endif /* DEBUG_FS */