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/kfifo.h>
25 #include <linux/poll.h>
26 #include <linux/timekeeping.h>
27 #include <uapi/linux/gpio.h>
31 #define CREATE_TRACE_POINTS
32 #include <trace/events/gpio.h>
34 /* Implementation infrastructure for GPIO interfaces.
36 * The GPIO programming interface allows for inlining speed-critical
37 * get/set operations for common cases, so that access to SOC-integrated
38 * GPIOs can sometimes cost only an instruction or two per bit.
42 /* When debugging, extend minimal trust to callers and platform code.
43 * Also emit diagnostic messages that may help initial bringup, when
44 * board setup or driver bugs are most common.
46 * Otherwise, minimize overhead in what may be bitbanging codepaths.
49 #define extra_checks 1
51 #define extra_checks 0
54 /* Device and char device-related information */
55 static DEFINE_IDA(gpio_ida
);
56 static dev_t gpio_devt
;
57 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
58 static struct bus_type gpio_bus_type
= {
62 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
63 * While any GPIO is requested, its gpio_chip is not removable;
64 * each GPIO's "requested" flag serves as a lock and refcount.
66 DEFINE_SPINLOCK(gpio_lock
);
68 static DEFINE_MUTEX(gpio_lookup_lock
);
69 static LIST_HEAD(gpio_lookup_list
);
70 LIST_HEAD(gpio_devices
);
72 static void gpiochip_free_hogs(struct gpio_chip
*chip
);
73 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
);
74 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
);
75 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
);
77 static bool gpiolib_initialized
;
79 static inline void desc_set_label(struct gpio_desc
*d
, const char *label
)
85 * Convert a GPIO number to its descriptor
87 struct gpio_desc
*gpio_to_desc(unsigned gpio
)
89 struct gpio_device
*gdev
;
92 spin_lock_irqsave(&gpio_lock
, flags
);
94 list_for_each_entry(gdev
, &gpio_devices
, list
) {
95 if (gdev
->base
<= gpio
&&
96 gdev
->base
+ gdev
->ngpio
> gpio
) {
97 spin_unlock_irqrestore(&gpio_lock
, flags
);
98 return &gdev
->descs
[gpio
- gdev
->base
];
102 spin_unlock_irqrestore(&gpio_lock
, flags
);
104 if (!gpio_is_valid(gpio
))
105 WARN(1, "invalid GPIO %d\n", gpio
);
109 EXPORT_SYMBOL_GPL(gpio_to_desc
);
112 * Get the GPIO descriptor corresponding to the given hw number for this chip.
114 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
117 struct gpio_device
*gdev
= chip
->gpiodev
;
119 if (hwnum
>= gdev
->ngpio
)
120 return ERR_PTR(-EINVAL
);
122 return &gdev
->descs
[hwnum
];
126 * Convert a GPIO descriptor to the integer namespace.
127 * This should disappear in the future but is needed since we still
128 * use GPIO numbers for error messages and sysfs nodes
130 int desc_to_gpio(const struct gpio_desc
*desc
)
132 return desc
->gdev
->base
+ (desc
- &desc
->gdev
->descs
[0]);
134 EXPORT_SYMBOL_GPL(desc_to_gpio
);
138 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
139 * @desc: descriptor to return the chip of
141 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
143 if (!desc
|| !desc
->gdev
|| !desc
->gdev
->chip
)
145 return desc
->gdev
->chip
;
147 EXPORT_SYMBOL_GPL(gpiod_to_chip
);
149 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
150 static int gpiochip_find_base(int ngpio
)
152 struct gpio_device
*gdev
;
153 int base
= ARCH_NR_GPIOS
- ngpio
;
155 list_for_each_entry_reverse(gdev
, &gpio_devices
, list
) {
156 /* found a free space? */
157 if (gdev
->base
+ gdev
->ngpio
<= base
)
160 /* nope, check the space right before the chip */
161 base
= gdev
->base
- ngpio
;
164 if (gpio_is_valid(base
)) {
165 pr_debug("%s: found new base at %d\n", __func__
, base
);
168 pr_err("%s: cannot find free range\n", __func__
);
174 * gpiod_get_direction - return the current direction of a GPIO
175 * @desc: GPIO to get the direction of
177 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
179 * This function may sleep if gpiod_cansleep() is true.
181 int gpiod_get_direction(struct gpio_desc
*desc
)
183 struct gpio_chip
*chip
;
185 int status
= -EINVAL
;
187 chip
= gpiod_to_chip(desc
);
188 offset
= gpio_chip_hwgpio(desc
);
190 if (!chip
->get_direction
)
193 status
= chip
->get_direction(chip
, offset
);
195 /* GPIOF_DIR_IN, or other positive */
197 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
201 set_bit(FLAG_IS_OUT
, &desc
->flags
);
205 EXPORT_SYMBOL_GPL(gpiod_get_direction
);
208 * Add a new chip to the global chips list, keeping the list of chips sorted
209 * by range(means [base, base + ngpio - 1]) order.
211 * Return -EBUSY if the new chip overlaps with some other chip's integer
214 static int gpiodev_add_to_list(struct gpio_device
*gdev
)
216 struct gpio_device
*prev
, *next
;
218 if (list_empty(&gpio_devices
)) {
219 /* initial entry in list */
220 list_add_tail(&gdev
->list
, &gpio_devices
);
224 next
= list_entry(gpio_devices
.next
, struct gpio_device
, list
);
225 if (gdev
->base
+ gdev
->ngpio
<= next
->base
) {
226 /* add before first entry */
227 list_add(&gdev
->list
, &gpio_devices
);
231 prev
= list_entry(gpio_devices
.prev
, struct gpio_device
, list
);
232 if (prev
->base
+ prev
->ngpio
<= gdev
->base
) {
233 /* add behind last entry */
234 list_add_tail(&gdev
->list
, &gpio_devices
);
238 list_for_each_entry_safe(prev
, next
, &gpio_devices
, list
) {
239 /* at the end of the list */
240 if (&next
->list
== &gpio_devices
)
243 /* add between prev and next */
244 if (prev
->base
+ prev
->ngpio
<= gdev
->base
245 && gdev
->base
+ gdev
->ngpio
<= next
->base
) {
246 list_add(&gdev
->list
, &prev
->list
);
251 dev_err(&gdev
->dev
, "GPIO integer space overlap, cannot add chip\n");
256 * Convert a GPIO name to its descriptor
258 static struct gpio_desc
*gpio_name_to_desc(const char * const name
)
260 struct gpio_device
*gdev
;
263 spin_lock_irqsave(&gpio_lock
, flags
);
265 list_for_each_entry(gdev
, &gpio_devices
, list
) {
268 for (i
= 0; i
!= gdev
->ngpio
; ++i
) {
269 struct gpio_desc
*desc
= &gdev
->descs
[i
];
271 if (!desc
->name
|| !name
)
274 if (!strcmp(desc
->name
, name
)) {
275 spin_unlock_irqrestore(&gpio_lock
, flags
);
281 spin_unlock_irqrestore(&gpio_lock
, flags
);
287 * Takes the names from gc->names and checks if they are all unique. If they
288 * are, they are assigned to their gpio descriptors.
290 * Warning if one of the names is already used for a different GPIO.
292 static int gpiochip_set_desc_names(struct gpio_chip
*gc
)
294 struct gpio_device
*gdev
= gc
->gpiodev
;
300 /* First check all names if they are unique */
301 for (i
= 0; i
!= gc
->ngpio
; ++i
) {
302 struct gpio_desc
*gpio
;
304 gpio
= gpio_name_to_desc(gc
->names
[i
]);
307 "Detected name collision for GPIO name '%s'\n",
311 /* Then add all names to the GPIO descriptors */
312 for (i
= 0; i
!= gc
->ngpio
; ++i
)
313 gdev
->descs
[i
].name
= gc
->names
[i
];
319 * GPIO line handle management
323 * struct linehandle_state - contains the state of a userspace handle
324 * @gdev: the GPIO device the handle pertains to
325 * @label: consumer label used to tag descriptors
326 * @descs: the GPIO descriptors held by this handle
327 * @numdescs: the number of descriptors held in the descs array
329 struct linehandle_state
{
330 struct gpio_device
*gdev
;
332 struct gpio_desc
*descs
[GPIOHANDLES_MAX
];
336 static long linehandle_ioctl(struct file
*filep
, unsigned int cmd
,
339 struct linehandle_state
*lh
= filep
->private_data
;
340 void __user
*ip
= (void __user
*)arg
;
341 struct gpiohandle_data ghd
;
344 if (cmd
== GPIOHANDLE_GET_LINE_VALUES_IOCTL
) {
347 /* TODO: check if descriptors are really input */
348 for (i
= 0; i
< lh
->numdescs
; i
++) {
349 val
= gpiod_get_value_cansleep(lh
->descs
[i
]);
355 if (copy_to_user(ip
, &ghd
, sizeof(ghd
)))
359 } else if (cmd
== GPIOHANDLE_SET_LINE_VALUES_IOCTL
) {
360 int vals
[GPIOHANDLES_MAX
];
362 /* TODO: check if descriptors are really output */
363 if (copy_from_user(&ghd
, ip
, sizeof(ghd
)))
366 /* Clamp all values to [0,1] */
367 for (i
= 0; i
< lh
->numdescs
; i
++)
368 vals
[i
] = !!ghd
.values
[i
];
370 /* Reuse the array setting function */
371 gpiod_set_array_value_complex(false,
382 static long linehandle_ioctl_compat(struct file
*filep
, unsigned int cmd
,
385 return linehandle_ioctl(filep
, cmd
, (unsigned long)compat_ptr(arg
));
389 static int linehandle_release(struct inode
*inode
, struct file
*filep
)
391 struct linehandle_state
*lh
= filep
->private_data
;
392 struct gpio_device
*gdev
= lh
->gdev
;
395 for (i
= 0; i
< lh
->numdescs
; i
++)
396 gpiod_free(lh
->descs
[i
]);
399 put_device(&gdev
->dev
);
403 static const struct file_operations linehandle_fileops
= {
404 .release
= linehandle_release
,
405 .owner
= THIS_MODULE
,
406 .llseek
= noop_llseek
,
407 .unlocked_ioctl
= linehandle_ioctl
,
409 .compat_ioctl
= linehandle_ioctl_compat
,
413 static int linehandle_create(struct gpio_device
*gdev
, void __user
*ip
)
415 struct gpiohandle_request handlereq
;
416 struct linehandle_state
*lh
;
419 if (copy_from_user(&handlereq
, ip
, sizeof(handlereq
)))
421 if ((handlereq
.lines
== 0) || (handlereq
.lines
> GPIOHANDLES_MAX
))
424 lh
= kzalloc(sizeof(*lh
), GFP_KERNEL
);
428 get_device(&gdev
->dev
);
430 /* Make sure this is terminated */
431 handlereq
.consumer_label
[sizeof(handlereq
.consumer_label
)-1] = '\0';
432 if (strlen(handlereq
.consumer_label
)) {
433 lh
->label
= kstrdup(handlereq
.consumer_label
,
441 /* Request each GPIO */
442 for (i
= 0; i
< handlereq
.lines
; i
++) {
443 u32 offset
= handlereq
.lineoffsets
[i
];
444 u32 lflags
= handlereq
.flags
;
445 struct gpio_desc
*desc
;
447 desc
= &gdev
->descs
[offset
];
448 ret
= gpiod_request(desc
, lh
->label
);
453 if (lflags
& GPIOHANDLE_REQUEST_ACTIVE_LOW
)
454 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
455 if (lflags
& GPIOHANDLE_REQUEST_OPEN_DRAIN
)
456 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
457 if (lflags
& GPIOHANDLE_REQUEST_OPEN_SOURCE
)
458 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
461 * Lines have to be requested explicitly for input
462 * or output, else the line will be treated "as is".
464 if (lflags
& GPIOHANDLE_REQUEST_OUTPUT
) {
465 int val
= !!handlereq
.default_values
[i
];
467 ret
= gpiod_direction_output(desc
, val
);
470 } else if (lflags
& GPIOHANDLE_REQUEST_INPUT
) {
471 ret
= gpiod_direction_input(desc
);
475 dev_dbg(&gdev
->dev
, "registered chardev handle for line %d\n",
478 /* Let i point at the last handle */
480 lh
->numdescs
= handlereq
.lines
;
482 fd
= anon_inode_getfd("gpio-linehandle",
485 O_RDONLY
| O_CLOEXEC
);
492 if (copy_to_user(ip
, &handlereq
, sizeof(handlereq
))) {
497 dev_dbg(&gdev
->dev
, "registered chardev handle for %d lines\n",
504 gpiod_free(lh
->descs
[i
]);
508 put_device(&gdev
->dev
);
513 * GPIO line event management
517 * struct lineevent_state - contains the state of a userspace event
518 * @gdev: the GPIO device the event pertains to
519 * @label: consumer label used to tag descriptors
520 * @desc: the GPIO descriptor held by this event
521 * @eflags: the event flags this line was requested with
522 * @irq: the interrupt that trigger in response to events on this GPIO
523 * @wait: wait queue that handles blocking reads of events
524 * @events: KFIFO for the GPIO events
525 * @read_lock: mutex lock to protect reads from colliding with adding
526 * new events to the FIFO
528 struct lineevent_state
{
529 struct gpio_device
*gdev
;
531 struct gpio_desc
*desc
;
534 wait_queue_head_t wait
;
535 DECLARE_KFIFO(events
, struct gpioevent_data
, 16);
536 struct mutex read_lock
;
539 static unsigned int lineevent_poll(struct file
*filep
,
540 struct poll_table_struct
*wait
)
542 struct lineevent_state
*le
= filep
->private_data
;
543 unsigned int events
= 0;
545 poll_wait(filep
, &le
->wait
, wait
);
547 if (!kfifo_is_empty(&le
->events
))
548 events
= POLLIN
| POLLRDNORM
;
554 static ssize_t
lineevent_read(struct file
*filep
,
559 struct lineevent_state
*le
= filep
->private_data
;
563 if (count
< sizeof(struct gpioevent_data
))
567 if (kfifo_is_empty(&le
->events
)) {
568 if (filep
->f_flags
& O_NONBLOCK
)
571 ret
= wait_event_interruptible(le
->wait
,
572 !kfifo_is_empty(&le
->events
));
577 if (mutex_lock_interruptible(&le
->read_lock
))
579 ret
= kfifo_to_user(&le
->events
, buf
, count
, &copied
);
580 mutex_unlock(&le
->read_lock
);
586 * If we couldn't read anything from the fifo (a different
587 * thread might have been faster) we either return -EAGAIN if
588 * the file descriptor is non-blocking, otherwise we go back to
589 * sleep and wait for more data to arrive.
591 if (copied
== 0 && (filep
->f_flags
& O_NONBLOCK
))
594 } while (copied
== 0);
599 static int lineevent_release(struct inode
*inode
, struct file
*filep
)
601 struct lineevent_state
*le
= filep
->private_data
;
602 struct gpio_device
*gdev
= le
->gdev
;
604 free_irq(le
->irq
, le
);
605 gpiod_free(le
->desc
);
608 put_device(&gdev
->dev
);
612 static long lineevent_ioctl(struct file
*filep
, unsigned int cmd
,
615 struct lineevent_state
*le
= filep
->private_data
;
616 void __user
*ip
= (void __user
*)arg
;
617 struct gpiohandle_data ghd
;
620 * We can get the value for an event line but not set it,
621 * because it is input by definition.
623 if (cmd
== GPIOHANDLE_GET_LINE_VALUES_IOCTL
) {
626 val
= gpiod_get_value_cansleep(le
->desc
);
631 if (copy_to_user(ip
, &ghd
, sizeof(ghd
)))
640 static long lineevent_ioctl_compat(struct file
*filep
, unsigned int cmd
,
643 return lineevent_ioctl(filep
, cmd
, (unsigned long)compat_ptr(arg
));
647 static const struct file_operations lineevent_fileops
= {
648 .release
= lineevent_release
,
649 .read
= lineevent_read
,
650 .poll
= lineevent_poll
,
651 .owner
= THIS_MODULE
,
652 .llseek
= noop_llseek
,
653 .unlocked_ioctl
= lineevent_ioctl
,
655 .compat_ioctl
= lineevent_ioctl_compat
,
659 static irqreturn_t
lineevent_irq_thread(int irq
, void *p
)
661 struct lineevent_state
*le
= p
;
662 struct gpioevent_data ge
;
665 ge
.timestamp
= ktime_get_real_ns();
667 if (le
->eflags
& GPIOEVENT_REQUEST_BOTH_EDGES
) {
668 int level
= gpiod_get_value_cansleep(le
->desc
);
671 /* Emit low-to-high event */
672 ge
.id
= GPIOEVENT_EVENT_RISING_EDGE
;
674 /* Emit high-to-low event */
675 ge
.id
= GPIOEVENT_EVENT_FALLING_EDGE
;
676 } else if (le
->eflags
& GPIOEVENT_REQUEST_RISING_EDGE
) {
677 /* Emit low-to-high event */
678 ge
.id
= GPIOEVENT_EVENT_RISING_EDGE
;
679 } else if (le
->eflags
& GPIOEVENT_REQUEST_FALLING_EDGE
) {
680 /* Emit high-to-low event */
681 ge
.id
= GPIOEVENT_EVENT_FALLING_EDGE
;
686 ret
= kfifo_put(&le
->events
, ge
);
688 wake_up_poll(&le
->wait
, POLLIN
);
693 static int lineevent_create(struct gpio_device
*gdev
, void __user
*ip
)
695 struct gpioevent_request eventreq
;
696 struct lineevent_state
*le
;
697 struct gpio_desc
*desc
;
705 if (copy_from_user(&eventreq
, ip
, sizeof(eventreq
)))
708 le
= kzalloc(sizeof(*le
), GFP_KERNEL
);
712 get_device(&gdev
->dev
);
714 /* Make sure this is terminated */
715 eventreq
.consumer_label
[sizeof(eventreq
.consumer_label
)-1] = '\0';
716 if (strlen(eventreq
.consumer_label
)) {
717 le
->label
= kstrdup(eventreq
.consumer_label
,
725 offset
= eventreq
.lineoffset
;
726 lflags
= eventreq
.handleflags
;
727 eflags
= eventreq
.eventflags
;
729 /* This is just wrong: we don't look for events on output lines */
730 if (lflags
& GPIOHANDLE_REQUEST_OUTPUT
) {
735 desc
= &gdev
->descs
[offset
];
736 ret
= gpiod_request(desc
, le
->label
);
742 if (lflags
& GPIOHANDLE_REQUEST_ACTIVE_LOW
)
743 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
744 if (lflags
& GPIOHANDLE_REQUEST_OPEN_DRAIN
)
745 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
746 if (lflags
& GPIOHANDLE_REQUEST_OPEN_SOURCE
)
747 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
749 ret
= gpiod_direction_input(desc
);
753 le
->irq
= gpiod_to_irq(desc
);
759 if (eflags
& GPIOEVENT_REQUEST_RISING_EDGE
)
760 irqflags
|= IRQF_TRIGGER_RISING
;
761 if (eflags
& GPIOEVENT_REQUEST_FALLING_EDGE
)
762 irqflags
|= IRQF_TRIGGER_FALLING
;
763 irqflags
|= IRQF_ONESHOT
;
764 irqflags
|= IRQF_SHARED
;
766 INIT_KFIFO(le
->events
);
767 init_waitqueue_head(&le
->wait
);
768 mutex_init(&le
->read_lock
);
770 /* Request a thread to read the events */
771 ret
= request_threaded_irq(le
->irq
,
773 lineevent_irq_thread
,
780 fd
= anon_inode_getfd("gpio-event",
783 O_RDONLY
| O_CLOEXEC
);
790 if (copy_to_user(ip
, &eventreq
, sizeof(eventreq
))) {
798 free_irq(le
->irq
, le
);
800 gpiod_free(le
->desc
);
805 put_device(&gdev
->dev
);
810 * gpio_ioctl() - ioctl handler for the GPIO chardev
812 static long gpio_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
814 struct gpio_device
*gdev
= filp
->private_data
;
815 struct gpio_chip
*chip
= gdev
->chip
;
816 void __user
*ip
= (void __user
*)arg
;
818 /* We fail any subsequent ioctl():s when the chip is gone */
822 /* Fill in the struct and pass to userspace */
823 if (cmd
== GPIO_GET_CHIPINFO_IOCTL
) {
824 struct gpiochip_info chipinfo
;
826 strncpy(chipinfo
.name
, dev_name(&gdev
->dev
),
827 sizeof(chipinfo
.name
));
828 chipinfo
.name
[sizeof(chipinfo
.name
)-1] = '\0';
829 strncpy(chipinfo
.label
, gdev
->label
,
830 sizeof(chipinfo
.label
));
831 chipinfo
.label
[sizeof(chipinfo
.label
)-1] = '\0';
832 chipinfo
.lines
= gdev
->ngpio
;
833 if (copy_to_user(ip
, &chipinfo
, sizeof(chipinfo
)))
836 } else if (cmd
== GPIO_GET_LINEINFO_IOCTL
) {
837 struct gpioline_info lineinfo
;
838 struct gpio_desc
*desc
;
840 if (copy_from_user(&lineinfo
, ip
, sizeof(lineinfo
)))
842 if (lineinfo
.line_offset
> gdev
->ngpio
)
845 desc
= &gdev
->descs
[lineinfo
.line_offset
];
847 strncpy(lineinfo
.name
, desc
->name
,
848 sizeof(lineinfo
.name
));
849 lineinfo
.name
[sizeof(lineinfo
.name
)-1] = '\0';
851 lineinfo
.name
[0] = '\0';
854 strncpy(lineinfo
.consumer
, desc
->label
,
855 sizeof(lineinfo
.consumer
));
856 lineinfo
.consumer
[sizeof(lineinfo
.consumer
)-1] = '\0';
858 lineinfo
.consumer
[0] = '\0';
862 * Userspace only need to know that the kernel is using
863 * this GPIO so it can't use it.
866 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) ||
867 test_bit(FLAG_IS_HOGGED
, &desc
->flags
) ||
868 test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
) ||
869 test_bit(FLAG_EXPORT
, &desc
->flags
) ||
870 test_bit(FLAG_SYSFS
, &desc
->flags
))
871 lineinfo
.flags
|= GPIOLINE_FLAG_KERNEL
;
872 if (test_bit(FLAG_IS_OUT
, &desc
->flags
))
873 lineinfo
.flags
|= GPIOLINE_FLAG_IS_OUT
;
874 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
875 lineinfo
.flags
|= GPIOLINE_FLAG_ACTIVE_LOW
;
876 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
877 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_DRAIN
;
878 if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
879 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_SOURCE
;
881 if (copy_to_user(ip
, &lineinfo
, sizeof(lineinfo
)))
884 } else if (cmd
== GPIO_GET_LINEHANDLE_IOCTL
) {
885 return linehandle_create(gdev
, ip
);
886 } else if (cmd
== GPIO_GET_LINEEVENT_IOCTL
) {
887 return lineevent_create(gdev
, ip
);
893 static long gpio_ioctl_compat(struct file
*filp
, unsigned int cmd
,
896 return gpio_ioctl(filp
, cmd
, (unsigned long)compat_ptr(arg
));
901 * gpio_chrdev_open() - open the chardev for ioctl operations
902 * @inode: inode for this chardev
903 * @filp: file struct for storing private data
904 * Returns 0 on success
906 static int gpio_chrdev_open(struct inode
*inode
, struct file
*filp
)
908 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
909 struct gpio_device
, chrdev
);
911 /* Fail on open if the backing gpiochip is gone */
912 if (!gdev
|| !gdev
->chip
)
914 get_device(&gdev
->dev
);
915 filp
->private_data
= gdev
;
920 * gpio_chrdev_release() - close chardev after ioctl operations
921 * @inode: inode for this chardev
922 * @filp: file struct for storing private data
923 * Returns 0 on success
925 static int gpio_chrdev_release(struct inode
*inode
, struct file
*filp
)
927 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
928 struct gpio_device
, chrdev
);
932 put_device(&gdev
->dev
);
937 static const struct file_operations gpio_fileops
= {
938 .release
= gpio_chrdev_release
,
939 .open
= gpio_chrdev_open
,
940 .owner
= THIS_MODULE
,
941 .llseek
= noop_llseek
,
942 .unlocked_ioctl
= gpio_ioctl
,
944 .compat_ioctl
= gpio_ioctl_compat
,
948 static void gpiodevice_release(struct device
*dev
)
950 struct gpio_device
*gdev
= dev_get_drvdata(dev
);
952 list_del(&gdev
->list
);
953 ida_simple_remove(&gpio_ida
, gdev
->id
);
959 static int gpiochip_setup_dev(struct gpio_device
*gdev
)
963 cdev_init(&gdev
->chrdev
, &gpio_fileops
);
964 gdev
->chrdev
.owner
= THIS_MODULE
;
965 gdev
->chrdev
.kobj
.parent
= &gdev
->dev
.kobj
;
966 gdev
->dev
.devt
= MKDEV(MAJOR(gpio_devt
), gdev
->id
);
967 status
= cdev_add(&gdev
->chrdev
, gdev
->dev
.devt
, 1);
969 chip_warn(gdev
->chip
, "failed to add char device %d:%d\n",
970 MAJOR(gpio_devt
), gdev
->id
);
972 chip_dbg(gdev
->chip
, "added GPIO chardev (%d:%d)\n",
973 MAJOR(gpio_devt
), gdev
->id
);
974 status
= device_add(&gdev
->dev
);
976 goto err_remove_chardev
;
978 status
= gpiochip_sysfs_register(gdev
);
980 goto err_remove_device
;
982 /* From this point, the .release() function cleans up gpio_device */
983 gdev
->dev
.release
= gpiodevice_release
;
984 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
985 __func__
, gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
986 dev_name(&gdev
->dev
), gdev
->chip
->label
? : "generic");
991 device_del(&gdev
->dev
);
993 cdev_del(&gdev
->chrdev
);
997 static void gpiochip_setup_devs(void)
999 struct gpio_device
*gdev
;
1002 list_for_each_entry(gdev
, &gpio_devices
, list
) {
1003 err
= gpiochip_setup_dev(gdev
);
1005 pr_err("%s: Failed to initialize gpio device (%d)\n",
1006 dev_name(&gdev
->dev
), err
);
1011 * gpiochip_add_data() - register a gpio_chip
1012 * @chip: the chip to register, with chip->base initialized
1013 * Context: potentially before irqs will work
1015 * Returns a negative errno if the chip can't be registered, such as
1016 * because the chip->base is invalid or already associated with a
1017 * different chip. Otherwise it returns zero as a success code.
1019 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1020 * can be freely used, the chip->parent device must be registered before
1021 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1022 * for GPIOs will fail rudely.
1024 * gpiochip_add_data() must only be called after gpiolib initialization,
1025 * ie after core_initcall().
1027 * If chip->base is negative, this requests dynamic assignment of
1028 * a range of valid GPIOs.
1030 int gpiochip_add_data(struct gpio_chip
*chip
, void *data
)
1032 unsigned long flags
;
1035 int base
= chip
->base
;
1036 struct gpio_device
*gdev
;
1039 * First: allocate and populate the internal stat container, and
1040 * set up the struct device.
1042 gdev
= kzalloc(sizeof(*gdev
), GFP_KERNEL
);
1045 gdev
->dev
.bus
= &gpio_bus_type
;
1047 chip
->gpiodev
= gdev
;
1049 gdev
->dev
.parent
= chip
->parent
;
1050 gdev
->dev
.of_node
= chip
->parent
->of_node
;
1053 #ifdef CONFIG_OF_GPIO
1054 /* If the gpiochip has an assigned OF node this takes precedence */
1056 gdev
->dev
.of_node
= chip
->of_node
;
1059 gdev
->id
= ida_simple_get(&gpio_ida
, 0, 0, GFP_KERNEL
);
1064 dev_set_name(&gdev
->dev
, "gpiochip%d", gdev
->id
);
1065 device_initialize(&gdev
->dev
);
1066 dev_set_drvdata(&gdev
->dev
, gdev
);
1067 if (chip
->parent
&& chip
->parent
->driver
)
1068 gdev
->owner
= chip
->parent
->driver
->owner
;
1069 else if (chip
->owner
)
1070 /* TODO: remove chip->owner */
1071 gdev
->owner
= chip
->owner
;
1073 gdev
->owner
= THIS_MODULE
;
1075 gdev
->descs
= kcalloc(chip
->ngpio
, sizeof(gdev
->descs
[0]), GFP_KERNEL
);
1081 if (chip
->ngpio
== 0) {
1082 chip_err(chip
, "tried to insert a GPIO chip with zero lines\n");
1084 goto err_free_descs
;
1088 gdev
->label
= kstrdup(chip
->label
, GFP_KERNEL
);
1090 gdev
->label
= kstrdup("unknown", GFP_KERNEL
);
1093 goto err_free_descs
;
1096 gdev
->ngpio
= chip
->ngpio
;
1099 spin_lock_irqsave(&gpio_lock
, flags
);
1102 * TODO: this allocates a Linux GPIO number base in the global
1103 * GPIO numberspace for this chip. In the long run we want to
1104 * get *rid* of this numberspace and use only descriptors, but
1105 * it may be a pipe dream. It will not happen before we get rid
1106 * of the sysfs interface anyways.
1109 base
= gpiochip_find_base(chip
->ngpio
);
1112 spin_unlock_irqrestore(&gpio_lock
, flags
);
1113 goto err_free_label
;
1116 * TODO: it should not be necessary to reflect the assigned
1117 * base outside of the GPIO subsystem. Go over drivers and
1118 * see if anyone makes use of this, else drop this and assign
1125 status
= gpiodev_add_to_list(gdev
);
1127 spin_unlock_irqrestore(&gpio_lock
, flags
);
1128 goto err_free_label
;
1131 spin_unlock_irqrestore(&gpio_lock
, flags
);
1133 for (i
= 0; i
< chip
->ngpio
; i
++) {
1134 struct gpio_desc
*desc
= &gdev
->descs
[i
];
1138 * REVISIT: most hardware initializes GPIOs as inputs
1139 * (often with pullups enabled) so power usage is
1140 * minimized. Linux code should set the gpio direction
1141 * first thing; but until it does, and in case
1142 * chip->get_direction is not set, we may expose the
1143 * wrong direction in sysfs.
1146 if (chip
->get_direction
) {
1148 * If we have .get_direction, set up the initial
1149 * direction flag from the hardware.
1151 int dir
= chip
->get_direction(chip
, i
);
1154 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1155 } else if (!chip
->direction_input
) {
1157 * If the chip lacks the .direction_input callback
1158 * we logically assume all lines are outputs.
1160 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1164 #ifdef CONFIG_PINCTRL
1165 INIT_LIST_HEAD(&gdev
->pin_ranges
);
1168 status
= gpiochip_set_desc_names(chip
);
1170 goto err_remove_from_list
;
1172 status
= gpiochip_irqchip_init_valid_mask(chip
);
1174 goto err_remove_from_list
;
1176 status
= of_gpiochip_add(chip
);
1178 goto err_remove_chip
;
1180 acpi_gpiochip_add(chip
);
1183 * By first adding the chardev, and then adding the device,
1184 * we get a device node entry in sysfs under
1185 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1186 * coldplug of device nodes and other udev business.
1187 * We can do this only if gpiolib has been initialized.
1188 * Otherwise, defer until later.
1190 if (gpiolib_initialized
) {
1191 status
= gpiochip_setup_dev(gdev
);
1193 goto err_remove_chip
;
1198 acpi_gpiochip_remove(chip
);
1199 gpiochip_free_hogs(chip
);
1200 of_gpiochip_remove(chip
);
1201 gpiochip_irqchip_free_valid_mask(chip
);
1202 err_remove_from_list
:
1203 spin_lock_irqsave(&gpio_lock
, flags
);
1204 list_del(&gdev
->list
);
1205 spin_unlock_irqrestore(&gpio_lock
, flags
);
1211 ida_simple_remove(&gpio_ida
, gdev
->id
);
1212 /* failures here can mean systems won't boot... */
1213 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__
,
1214 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
1215 chip
->label
? : "generic");
1219 EXPORT_SYMBOL_GPL(gpiochip_add_data
);
1222 * gpiochip_get_data() - get per-subdriver data for the chip
1224 void *gpiochip_get_data(struct gpio_chip
*chip
)
1226 return chip
->gpiodev
->data
;
1228 EXPORT_SYMBOL_GPL(gpiochip_get_data
);
1231 * gpiochip_remove() - unregister a gpio_chip
1232 * @chip: the chip to unregister
1234 * A gpio_chip with any GPIOs still requested may not be removed.
1236 void gpiochip_remove(struct gpio_chip
*chip
)
1238 struct gpio_device
*gdev
= chip
->gpiodev
;
1239 struct gpio_desc
*desc
;
1240 unsigned long flags
;
1242 bool requested
= false;
1244 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1245 gpiochip_sysfs_unregister(gdev
);
1246 /* Numb the device, cancelling all outstanding operations */
1248 gpiochip_irqchip_remove(chip
);
1249 acpi_gpiochip_remove(chip
);
1250 gpiochip_remove_pin_ranges(chip
);
1251 gpiochip_free_hogs(chip
);
1252 of_gpiochip_remove(chip
);
1254 * We accept no more calls into the driver from this point, so
1255 * NULL the driver data pointer
1259 spin_lock_irqsave(&gpio_lock
, flags
);
1260 for (i
= 0; i
< gdev
->ngpio
; i
++) {
1261 desc
= &gdev
->descs
[i
];
1262 if (test_bit(FLAG_REQUESTED
, &desc
->flags
))
1265 spin_unlock_irqrestore(&gpio_lock
, flags
);
1268 dev_crit(&gdev
->dev
,
1269 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1272 * The gpiochip side puts its use of the device to rest here:
1273 * if there are no userspace clients, the chardev and device will
1274 * be removed, else it will be dangling until the last user is
1277 cdev_del(&gdev
->chrdev
);
1278 device_del(&gdev
->dev
);
1279 put_device(&gdev
->dev
);
1281 EXPORT_SYMBOL_GPL(gpiochip_remove
);
1283 static void devm_gpio_chip_release(struct device
*dev
, void *res
)
1285 struct gpio_chip
*chip
= *(struct gpio_chip
**)res
;
1287 gpiochip_remove(chip
);
1290 static int devm_gpio_chip_match(struct device
*dev
, void *res
, void *data
)
1293 struct gpio_chip
**r
= res
;
1304 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1305 * @dev: the device pointer on which irq_chip belongs to.
1306 * @chip: the chip to register, with chip->base initialized
1307 * Context: potentially before irqs will work
1309 * Returns a negative errno if the chip can't be registered, such as
1310 * because the chip->base is invalid or already associated with a
1311 * different chip. Otherwise it returns zero as a success code.
1313 * The gpio chip automatically be released when the device is unbound.
1315 int devm_gpiochip_add_data(struct device
*dev
, struct gpio_chip
*chip
,
1318 struct gpio_chip
**ptr
;
1321 ptr
= devres_alloc(devm_gpio_chip_release
, sizeof(*ptr
),
1326 ret
= gpiochip_add_data(chip
, data
);
1333 devres_add(dev
, ptr
);
1337 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data
);
1340 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1341 * @dev: device for which which resource was allocated
1342 * @chip: the chip to remove
1344 * A gpio_chip with any GPIOs still requested may not be removed.
1346 void devm_gpiochip_remove(struct device
*dev
, struct gpio_chip
*chip
)
1350 ret
= devres_release(dev
, devm_gpio_chip_release
,
1351 devm_gpio_chip_match
, chip
);
1355 EXPORT_SYMBOL_GPL(devm_gpiochip_remove
);
1358 * gpiochip_find() - iterator for locating a specific gpio_chip
1359 * @data: data to pass to match function
1360 * @callback: Callback function to check gpio_chip
1362 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1363 * determined by a user supplied @match callback. The callback should return
1364 * 0 if the device doesn't match and non-zero if it does. If the callback is
1365 * non-zero, this function will return to the caller and not iterate over any
1368 struct gpio_chip
*gpiochip_find(void *data
,
1369 int (*match
)(struct gpio_chip
*chip
,
1372 struct gpio_device
*gdev
;
1373 struct gpio_chip
*chip
= NULL
;
1374 unsigned long flags
;
1376 spin_lock_irqsave(&gpio_lock
, flags
);
1377 list_for_each_entry(gdev
, &gpio_devices
, list
)
1378 if (gdev
->chip
&& match(gdev
->chip
, data
)) {
1383 spin_unlock_irqrestore(&gpio_lock
, flags
);
1387 EXPORT_SYMBOL_GPL(gpiochip_find
);
1389 static int gpiochip_match_name(struct gpio_chip
*chip
, void *data
)
1391 const char *name
= data
;
1393 return !strcmp(chip
->label
, name
);
1396 static struct gpio_chip
*find_chip_by_name(const char *name
)
1398 return gpiochip_find((void *)name
, gpiochip_match_name
);
1401 #ifdef CONFIG_GPIOLIB_IRQCHIP
1404 * The following is irqchip helper code for gpiochips.
1407 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
)
1411 if (!gpiochip
->irq_need_valid_mask
)
1414 gpiochip
->irq_valid_mask
= kcalloc(BITS_TO_LONGS(gpiochip
->ngpio
),
1415 sizeof(long), GFP_KERNEL
);
1416 if (!gpiochip
->irq_valid_mask
)
1419 /* Assume by default all GPIOs are valid */
1420 for (i
= 0; i
< gpiochip
->ngpio
; i
++)
1421 set_bit(i
, gpiochip
->irq_valid_mask
);
1426 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
)
1428 kfree(gpiochip
->irq_valid_mask
);
1429 gpiochip
->irq_valid_mask
= NULL
;
1432 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip
*gpiochip
,
1433 unsigned int offset
)
1435 /* No mask means all valid */
1436 if (likely(!gpiochip
->irq_valid_mask
))
1438 return test_bit(offset
, gpiochip
->irq_valid_mask
);
1442 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
1443 * @gpiochip: the gpiochip to set the irqchip chain to
1444 * @irqchip: the irqchip to chain to the gpiochip
1445 * @parent_irq: the irq number corresponding to the parent IRQ for this
1447 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1448 * coming out of the gpiochip. If the interrupt is nested rather than
1449 * cascaded, pass NULL in this handler argument
1451 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
1452 struct irq_chip
*irqchip
,
1454 irq_flow_handler_t parent_handler
)
1456 unsigned int offset
;
1458 if (!gpiochip
->irqdomain
) {
1459 chip_err(gpiochip
, "called %s before setting up irqchip\n",
1464 if (parent_handler
) {
1465 if (gpiochip
->can_sleep
) {
1467 "you cannot have chained interrupts on a "
1468 "chip that may sleep\n");
1472 * The parent irqchip is already using the chip_data for this
1473 * irqchip, so our callbacks simply use the handler_data.
1475 irq_set_chained_handler_and_data(parent_irq
, parent_handler
,
1478 gpiochip
->irq_parent
= parent_irq
;
1481 /* Set the parent IRQ for all affected IRQs */
1482 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1483 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1485 irq_set_parent(irq_find_mapping(gpiochip
->irqdomain
, offset
),
1489 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip
);
1492 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1493 * @d: the irqdomain used by this irqchip
1494 * @irq: the global irq number used by this GPIO irqchip irq
1495 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1497 * This function will set up the mapping for a certain IRQ line on a
1498 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1499 * stored inside the gpiochip.
1501 static int gpiochip_irq_map(struct irq_domain
*d
, unsigned int irq
,
1502 irq_hw_number_t hwirq
)
1504 struct gpio_chip
*chip
= d
->host_data
;
1506 irq_set_chip_data(irq
, chip
);
1508 * This lock class tells lockdep that GPIO irqs are in a different
1509 * category than their parents, so it won't report false recursion.
1511 irq_set_lockdep_class(irq
, chip
->lock_key
);
1512 irq_set_chip_and_handler(irq
, chip
->irqchip
, chip
->irq_handler
);
1513 /* Chips that can sleep need nested thread handlers */
1514 if (chip
->can_sleep
&& !chip
->irq_not_threaded
)
1515 irq_set_nested_thread(irq
, 1);
1516 irq_set_noprobe(irq
);
1519 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1520 * is passed as default type.
1522 if (chip
->irq_default_type
!= IRQ_TYPE_NONE
)
1523 irq_set_irq_type(irq
, chip
->irq_default_type
);
1528 static void gpiochip_irq_unmap(struct irq_domain
*d
, unsigned int irq
)
1530 struct gpio_chip
*chip
= d
->host_data
;
1532 if (chip
->can_sleep
)
1533 irq_set_nested_thread(irq
, 0);
1534 irq_set_chip_and_handler(irq
, NULL
, NULL
);
1535 irq_set_chip_data(irq
, NULL
);
1538 static const struct irq_domain_ops gpiochip_domain_ops
= {
1539 .map
= gpiochip_irq_map
,
1540 .unmap
= gpiochip_irq_unmap
,
1541 /* Virtually all GPIO irqchips are twocell:ed */
1542 .xlate
= irq_domain_xlate_twocell
,
1545 static int gpiochip_irq_reqres(struct irq_data
*d
)
1547 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1549 if (!try_module_get(chip
->gpiodev
->owner
))
1552 if (gpiochip_lock_as_irq(chip
, d
->hwirq
)) {
1554 "unable to lock HW IRQ %lu for IRQ\n",
1556 module_put(chip
->gpiodev
->owner
);
1562 static void gpiochip_irq_relres(struct irq_data
*d
)
1564 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1566 gpiochip_unlock_as_irq(chip
, d
->hwirq
);
1567 module_put(chip
->gpiodev
->owner
);
1570 static int gpiochip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
1572 return irq_find_mapping(chip
->irqdomain
, offset
);
1576 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1577 * @gpiochip: the gpiochip to remove the irqchip from
1579 * This is called only from gpiochip_remove()
1581 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
)
1583 unsigned int offset
;
1585 acpi_gpiochip_free_interrupts(gpiochip
);
1587 if (gpiochip
->irq_parent
) {
1588 irq_set_chained_handler(gpiochip
->irq_parent
, NULL
);
1589 irq_set_handler_data(gpiochip
->irq_parent
, NULL
);
1592 /* Remove all IRQ mappings and delete the domain */
1593 if (gpiochip
->irqdomain
) {
1594 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1595 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1597 irq_dispose_mapping(
1598 irq_find_mapping(gpiochip
->irqdomain
, offset
));
1600 irq_domain_remove(gpiochip
->irqdomain
);
1603 if (gpiochip
->irqchip
) {
1604 gpiochip
->irqchip
->irq_request_resources
= NULL
;
1605 gpiochip
->irqchip
->irq_release_resources
= NULL
;
1606 gpiochip
->irqchip
= NULL
;
1609 gpiochip_irqchip_free_valid_mask(gpiochip
);
1613 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1614 * @gpiochip: the gpiochip to add the irqchip to
1615 * @irqchip: the irqchip to add to the gpiochip
1616 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1617 * allocate gpiochip irqs from
1618 * @handler: the irq handler to use (often a predefined irq core function)
1619 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1620 * to have the core avoid setting up any default type in the hardware.
1621 * @lock_key: lockdep class
1623 * This function closely associates a certain irqchip with a certain
1624 * gpiochip, providing an irq domain to translate the local IRQs to
1625 * global irqs in the gpiolib core, and making sure that the gpiochip
1626 * is passed as chip data to all related functions. Driver callbacks
1627 * need to use gpiochip_get_data() to get their local state containers back
1628 * from the gpiochip passed as chip data. An irqdomain will be stored
1629 * in the gpiochip that shall be used by the driver to handle IRQ number
1630 * translation. The gpiochip will need to be initialized and registered
1631 * before calling this function.
1633 * This function will handle two cell:ed simple IRQs and assumes all
1634 * the pins on the gpiochip can generate a unique IRQ. Everything else
1635 * need to be open coded.
1637 int _gpiochip_irqchip_add(struct gpio_chip
*gpiochip
,
1638 struct irq_chip
*irqchip
,
1639 unsigned int first_irq
,
1640 irq_flow_handler_t handler
,
1642 struct lock_class_key
*lock_key
)
1644 struct device_node
*of_node
;
1645 bool irq_base_set
= false;
1646 unsigned int offset
;
1647 unsigned irq_base
= 0;
1649 if (!gpiochip
|| !irqchip
)
1652 if (!gpiochip
->parent
) {
1653 pr_err("missing gpiochip .dev parent pointer\n");
1656 of_node
= gpiochip
->parent
->of_node
;
1657 #ifdef CONFIG_OF_GPIO
1659 * If the gpiochip has an assigned OF node this takes precedence
1660 * FIXME: get rid of this and use gpiochip->parent->of_node
1663 if (gpiochip
->of_node
)
1664 of_node
= gpiochip
->of_node
;
1667 * Specifying a default trigger is a terrible idea if DT or ACPI is
1668 * used to configure the interrupts, as you may end-up with
1669 * conflicting triggers. Tell the user, and reset to NONE.
1671 if (WARN(of_node
&& type
!= IRQ_TYPE_NONE
,
1672 "%s: Ignoring %d default trigger\n", of_node
->full_name
, type
))
1673 type
= IRQ_TYPE_NONE
;
1674 if (has_acpi_companion(gpiochip
->parent
) && type
!= IRQ_TYPE_NONE
) {
1675 acpi_handle_warn(ACPI_HANDLE(gpiochip
->parent
),
1676 "Ignoring %d default trigger\n", type
);
1677 type
= IRQ_TYPE_NONE
;
1680 gpiochip
->irqchip
= irqchip
;
1681 gpiochip
->irq_handler
= handler
;
1682 gpiochip
->irq_default_type
= type
;
1683 gpiochip
->to_irq
= gpiochip_to_irq
;
1684 gpiochip
->lock_key
= lock_key
;
1685 gpiochip
->irqdomain
= irq_domain_add_simple(of_node
,
1686 gpiochip
->ngpio
, first_irq
,
1687 &gpiochip_domain_ops
, gpiochip
);
1688 if (!gpiochip
->irqdomain
) {
1689 gpiochip
->irqchip
= NULL
;
1694 * It is possible for a driver to override this, but only if the
1695 * alternative functions are both implemented.
1697 if (!irqchip
->irq_request_resources
&&
1698 !irqchip
->irq_release_resources
) {
1699 irqchip
->irq_request_resources
= gpiochip_irq_reqres
;
1700 irqchip
->irq_release_resources
= gpiochip_irq_relres
;
1704 * Prepare the mapping since the irqchip shall be orthogonal to
1705 * any gpiochip calls. If the first_irq was zero, this is
1706 * necessary to allocate descriptors for all IRQs.
1708 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1709 if (!gpiochip_irqchip_irq_valid(gpiochip
, offset
))
1711 irq_base
= irq_create_mapping(gpiochip
->irqdomain
, offset
);
1712 if (!irq_base_set
) {
1714 * Store the base into the gpiochip to be used when
1715 * unmapping the irqs.
1717 gpiochip
->irq_base
= irq_base
;
1718 irq_base_set
= true;
1722 acpi_gpiochip_request_interrupts(gpiochip
);
1726 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add
);
1728 #else /* CONFIG_GPIOLIB_IRQCHIP */
1730 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
) {}
1731 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip
*gpiochip
)
1735 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip
*gpiochip
)
1738 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1741 * gpiochip_generic_request() - request the gpio function for a pin
1742 * @chip: the gpiochip owning the GPIO
1743 * @offset: the offset of the GPIO to request for GPIO function
1745 int gpiochip_generic_request(struct gpio_chip
*chip
, unsigned offset
)
1747 return pinctrl_request_gpio(chip
->gpiodev
->base
+ offset
);
1749 EXPORT_SYMBOL_GPL(gpiochip_generic_request
);
1752 * gpiochip_generic_free() - free the gpio function from a pin
1753 * @chip: the gpiochip to request the gpio function for
1754 * @offset: the offset of the GPIO to free from GPIO function
1756 void gpiochip_generic_free(struct gpio_chip
*chip
, unsigned offset
)
1758 pinctrl_free_gpio(chip
->gpiodev
->base
+ offset
);
1760 EXPORT_SYMBOL_GPL(gpiochip_generic_free
);
1762 #ifdef CONFIG_PINCTRL
1765 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1766 * @chip: the gpiochip to add the range for
1767 * @pctldev: the pin controller to map to
1768 * @gpio_offset: the start offset in the current gpio_chip number space
1769 * @pin_group: name of the pin group inside the pin controller
1771 int gpiochip_add_pingroup_range(struct gpio_chip
*chip
,
1772 struct pinctrl_dev
*pctldev
,
1773 unsigned int gpio_offset
, const char *pin_group
)
1775 struct gpio_pin_range
*pin_range
;
1776 struct gpio_device
*gdev
= chip
->gpiodev
;
1779 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1781 chip_err(chip
, "failed to allocate pin ranges\n");
1785 /* Use local offset as range ID */
1786 pin_range
->range
.id
= gpio_offset
;
1787 pin_range
->range
.gc
= chip
;
1788 pin_range
->range
.name
= chip
->label
;
1789 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1790 pin_range
->pctldev
= pctldev
;
1792 ret
= pinctrl_get_group_pins(pctldev
, pin_group
,
1793 &pin_range
->range
.pins
,
1794 &pin_range
->range
.npins
);
1800 pinctrl_add_gpio_range(pctldev
, &pin_range
->range
);
1802 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1803 gpio_offset
, gpio_offset
+ pin_range
->range
.npins
- 1,
1804 pinctrl_dev_get_devname(pctldev
), pin_group
);
1806 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1810 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range
);
1813 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1814 * @chip: the gpiochip to add the range for
1815 * @pinctrl_name: the dev_name() of the pin controller to map to
1816 * @gpio_offset: the start offset in the current gpio_chip number space
1817 * @pin_offset: the start offset in the pin controller number space
1818 * @npins: the number of pins from the offset of each pin space (GPIO and
1819 * pin controller) to accumulate in this range
1821 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
1822 unsigned int gpio_offset
, unsigned int pin_offset
,
1825 struct gpio_pin_range
*pin_range
;
1826 struct gpio_device
*gdev
= chip
->gpiodev
;
1829 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1831 chip_err(chip
, "failed to allocate pin ranges\n");
1835 /* Use local offset as range ID */
1836 pin_range
->range
.id
= gpio_offset
;
1837 pin_range
->range
.gc
= chip
;
1838 pin_range
->range
.name
= chip
->label
;
1839 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1840 pin_range
->range
.pin_base
= pin_offset
;
1841 pin_range
->range
.npins
= npins
;
1842 pin_range
->pctldev
= pinctrl_find_and_add_gpio_range(pinctl_name
,
1844 if (IS_ERR(pin_range
->pctldev
)) {
1845 ret
= PTR_ERR(pin_range
->pctldev
);
1846 chip_err(chip
, "could not create pin range\n");
1850 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1851 gpio_offset
, gpio_offset
+ npins
- 1,
1853 pin_offset
, pin_offset
+ npins
- 1);
1855 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1859 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range
);
1862 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1863 * @chip: the chip to remove all the mappings for
1865 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
1867 struct gpio_pin_range
*pin_range
, *tmp
;
1868 struct gpio_device
*gdev
= chip
->gpiodev
;
1870 list_for_each_entry_safe(pin_range
, tmp
, &gdev
->pin_ranges
, node
) {
1871 list_del(&pin_range
->node
);
1872 pinctrl_remove_gpio_range(pin_range
->pctldev
,
1877 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges
);
1879 #endif /* CONFIG_PINCTRL */
1881 /* These "optional" allocation calls help prevent drivers from stomping
1882 * on each other, and help provide better diagnostics in debugfs.
1883 * They're called even less than the "set direction" calls.
1885 static int __gpiod_request(struct gpio_desc
*desc
, const char *label
)
1887 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1889 unsigned long flags
;
1891 spin_lock_irqsave(&gpio_lock
, flags
);
1893 /* NOTE: gpio_request() can be called in early boot,
1894 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1897 if (test_and_set_bit(FLAG_REQUESTED
, &desc
->flags
) == 0) {
1898 desc_set_label(desc
, label
? : "?");
1905 if (chip
->request
) {
1906 /* chip->request may sleep */
1907 spin_unlock_irqrestore(&gpio_lock
, flags
);
1908 status
= chip
->request(chip
, gpio_chip_hwgpio(desc
));
1909 spin_lock_irqsave(&gpio_lock
, flags
);
1912 desc_set_label(desc
, NULL
);
1913 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1917 if (chip
->get_direction
) {
1918 /* chip->get_direction may sleep */
1919 spin_unlock_irqrestore(&gpio_lock
, flags
);
1920 gpiod_get_direction(desc
);
1921 spin_lock_irqsave(&gpio_lock
, flags
);
1924 spin_unlock_irqrestore(&gpio_lock
, flags
);
1929 * This descriptor validation needs to be inserted verbatim into each
1930 * function taking a descriptor, so we need to use a preprocessor
1931 * macro to avoid endless duplication. If the desc is NULL it is an
1932 * optional GPIO and calls should just bail out.
1934 #define VALIDATE_DESC(desc) do { \
1937 if (IS_ERR(desc)) { \
1938 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1939 return PTR_ERR(desc); \
1941 if (!desc->gdev) { \
1942 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1945 if ( !desc->gdev->chip ) { \
1946 dev_warn(&desc->gdev->dev, \
1947 "%s: backing chip is gone\n", __func__); \
1951 #define VALIDATE_DESC_VOID(desc) do { \
1954 if (IS_ERR(desc)) { \
1955 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1958 if (!desc->gdev) { \
1959 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1962 if (!desc->gdev->chip) { \
1963 dev_warn(&desc->gdev->dev, \
1964 "%s: backing chip is gone\n", __func__); \
1969 int gpiod_request(struct gpio_desc
*desc
, const char *label
)
1971 int status
= -EPROBE_DEFER
;
1972 struct gpio_device
*gdev
;
1974 VALIDATE_DESC(desc
);
1977 if (try_module_get(gdev
->owner
)) {
1978 status
= __gpiod_request(desc
, label
);
1980 module_put(gdev
->owner
);
1982 get_device(&gdev
->dev
);
1986 gpiod_dbg(desc
, "%s: status %d\n", __func__
, status
);
1991 static bool __gpiod_free(struct gpio_desc
*desc
)
1994 unsigned long flags
;
1995 struct gpio_chip
*chip
;
1999 gpiod_unexport(desc
);
2001 spin_lock_irqsave(&gpio_lock
, flags
);
2003 chip
= desc
->gdev
->chip
;
2004 if (chip
&& test_bit(FLAG_REQUESTED
, &desc
->flags
)) {
2006 spin_unlock_irqrestore(&gpio_lock
, flags
);
2007 might_sleep_if(chip
->can_sleep
);
2008 chip
->free(chip
, gpio_chip_hwgpio(desc
));
2009 spin_lock_irqsave(&gpio_lock
, flags
);
2011 desc_set_label(desc
, NULL
);
2012 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2013 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
2014 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2015 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2016 clear_bit(FLAG_IS_HOGGED
, &desc
->flags
);
2020 spin_unlock_irqrestore(&gpio_lock
, flags
);
2024 void gpiod_free(struct gpio_desc
*desc
)
2026 if (desc
&& desc
->gdev
&& __gpiod_free(desc
)) {
2027 module_put(desc
->gdev
->owner
);
2028 put_device(&desc
->gdev
->dev
);
2030 WARN_ON(extra_checks
);
2035 * gpiochip_is_requested - return string iff signal was requested
2036 * @chip: controller managing the signal
2037 * @offset: of signal within controller's 0..(ngpio - 1) range
2039 * Returns NULL if the GPIO is not currently requested, else a string.
2040 * The string returned is the label passed to gpio_request(); if none has been
2041 * passed it is a meaningless, non-NULL constant.
2043 * This function is for use by GPIO controller drivers. The label can
2044 * help with diagnostics, and knowing that the signal is used as a GPIO
2045 * can help avoid accidentally multiplexing it to another controller.
2047 const char *gpiochip_is_requested(struct gpio_chip
*chip
, unsigned offset
)
2049 struct gpio_desc
*desc
;
2051 if (offset
>= chip
->ngpio
)
2054 desc
= &chip
->gpiodev
->descs
[offset
];
2056 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) == 0)
2060 EXPORT_SYMBOL_GPL(gpiochip_is_requested
);
2063 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2064 * @desc: GPIO descriptor to request
2065 * @label: label for the GPIO
2067 * Function allows GPIO chip drivers to request and use their own GPIO
2068 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2069 * function will not increase reference count of the GPIO chip module. This
2070 * allows the GPIO chip module to be unloaded as needed (we assume that the
2071 * GPIO chip driver handles freeing the GPIOs it has requested).
2073 struct gpio_desc
*gpiochip_request_own_desc(struct gpio_chip
*chip
, u16 hwnum
,
2076 struct gpio_desc
*desc
= gpiochip_get_desc(chip
, hwnum
);
2080 chip_err(chip
, "failed to get GPIO descriptor\n");
2084 err
= __gpiod_request(desc
, label
);
2086 return ERR_PTR(err
);
2090 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc
);
2093 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2094 * @desc: GPIO descriptor to free
2096 * Function frees the given GPIO requested previously with
2097 * gpiochip_request_own_desc().
2099 void gpiochip_free_own_desc(struct gpio_desc
*desc
)
2104 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc
);
2107 * Drivers MUST set GPIO direction before making get/set calls. In
2108 * some cases this is done in early boot, before IRQs are enabled.
2110 * As a rule these aren't called more than once (except for drivers
2111 * using the open-drain emulation idiom) so these are natural places
2112 * to accumulate extra debugging checks. Note that we can't (yet)
2113 * rely on gpio_request() having been called beforehand.
2117 * gpiod_direction_input - set the GPIO direction to input
2118 * @desc: GPIO to set to input
2120 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2121 * be called safely on it.
2123 * Return 0 in case of success, else an error code.
2125 int gpiod_direction_input(struct gpio_desc
*desc
)
2127 struct gpio_chip
*chip
;
2128 int status
= -EINVAL
;
2130 VALIDATE_DESC(desc
);
2131 chip
= desc
->gdev
->chip
;
2133 if (!chip
->get
|| !chip
->direction_input
) {
2135 "%s: missing get() or direction_input() operations\n",
2140 status
= chip
->direction_input(chip
, gpio_chip_hwgpio(desc
));
2142 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2144 trace_gpio_direction(desc_to_gpio(desc
), 1, status
);
2148 EXPORT_SYMBOL_GPL(gpiod_direction_input
);
2150 static int _gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
2152 struct gpio_chip
*gc
= desc
->gdev
->chip
;
2155 /* GPIOs used for IRQs shall not be set as output */
2156 if (test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
)) {
2158 "%s: tried to set a GPIO tied to an IRQ as output\n",
2163 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
2164 /* First see if we can enable open drain in hardware */
2165 if (gc
->set_single_ended
) {
2166 ret
= gc
->set_single_ended(gc
, gpio_chip_hwgpio(desc
),
2167 LINE_MODE_OPEN_DRAIN
);
2169 goto set_output_value
;
2171 /* Emulate open drain by not actively driving the line high */
2173 return gpiod_direction_input(desc
);
2175 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
2176 if (gc
->set_single_ended
) {
2177 ret
= gc
->set_single_ended(gc
, gpio_chip_hwgpio(desc
),
2178 LINE_MODE_OPEN_SOURCE
);
2180 goto set_output_value
;
2182 /* Emulate open source by not actively driving the line low */
2184 return gpiod_direction_input(desc
);
2186 /* Make sure to disable open drain/source hardware, if any */
2187 if (gc
->set_single_ended
)
2188 gc
->set_single_ended(gc
,
2189 gpio_chip_hwgpio(desc
),
2190 LINE_MODE_PUSH_PULL
);
2194 if (!gc
->set
|| !gc
->direction_output
) {
2196 "%s: missing set() or direction_output() operations\n",
2201 ret
= gc
->direction_output(gc
, gpio_chip_hwgpio(desc
), value
);
2203 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2204 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
2205 trace_gpio_direction(desc_to_gpio(desc
), 0, ret
);
2210 * gpiod_direction_output_raw - set the GPIO direction to output
2211 * @desc: GPIO to set to output
2212 * @value: initial output value of the GPIO
2214 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2215 * be called safely on it. The initial value of the output must be specified
2216 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2218 * Return 0 in case of success, else an error code.
2220 int gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
2222 VALIDATE_DESC(desc
);
2223 return _gpiod_direction_output_raw(desc
, value
);
2225 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw
);
2228 * gpiod_direction_output - set the GPIO direction to output
2229 * @desc: GPIO to set to output
2230 * @value: initial output value of the GPIO
2232 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2233 * be called safely on it. The initial value of the output must be specified
2234 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2237 * Return 0 in case of success, else an error code.
2239 int gpiod_direction_output(struct gpio_desc
*desc
, int value
)
2241 VALIDATE_DESC(desc
);
2242 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2244 return _gpiod_direction_output_raw(desc
, value
);
2246 EXPORT_SYMBOL_GPL(gpiod_direction_output
);
2249 * gpiod_set_debounce - sets @debounce time for a @gpio
2250 * @gpio: the gpio to set debounce time
2251 * @debounce: debounce time is microseconds
2253 * returns -ENOTSUPP if the controller does not support setting
2256 int gpiod_set_debounce(struct gpio_desc
*desc
, unsigned debounce
)
2258 struct gpio_chip
*chip
;
2260 VALIDATE_DESC(desc
);
2261 chip
= desc
->gdev
->chip
;
2262 if (!chip
->set
|| !chip
->set_debounce
) {
2264 "%s: missing set() or set_debounce() operations\n",
2269 return chip
->set_debounce(chip
, gpio_chip_hwgpio(desc
), debounce
);
2271 EXPORT_SYMBOL_GPL(gpiod_set_debounce
);
2274 * gpiod_is_active_low - test whether a GPIO is active-low or not
2275 * @desc: the gpio descriptor to test
2277 * Returns 1 if the GPIO is active-low, 0 otherwise.
2279 int gpiod_is_active_low(const struct gpio_desc
*desc
)
2281 VALIDATE_DESC(desc
);
2282 return test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2284 EXPORT_SYMBOL_GPL(gpiod_is_active_low
);
2286 /* I/O calls are only valid after configuration completed; the relevant
2287 * "is this a valid GPIO" error checks should already have been done.
2289 * "Get" operations are often inlinable as reading a pin value register,
2290 * and masking the relevant bit in that register.
2292 * When "set" operations are inlinable, they involve writing that mask to
2293 * one register to set a low value, or a different register to set it high.
2294 * Otherwise locking is needed, so there may be little value to inlining.
2296 *------------------------------------------------------------------------
2298 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2299 * have requested the GPIO. That can include implicit requesting by
2300 * a direction setting call. Marking a gpio as requested locks its chip
2301 * in memory, guaranteeing that these table lookups need no more locking
2302 * and that gpiochip_remove() will fail.
2304 * REVISIT when debugging, consider adding some instrumentation to ensure
2305 * that the GPIO was actually requested.
2308 static int _gpiod_get_raw_value(const struct gpio_desc
*desc
)
2310 struct gpio_chip
*chip
;
2314 chip
= desc
->gdev
->chip
;
2315 offset
= gpio_chip_hwgpio(desc
);
2316 value
= chip
->get
? chip
->get(chip
, offset
) : -EIO
;
2317 value
= value
< 0 ? value
: !!value
;
2318 trace_gpio_value(desc_to_gpio(desc
), 1, value
);
2323 * gpiod_get_raw_value() - return a gpio's raw value
2324 * @desc: gpio whose value will be returned
2326 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2327 * its ACTIVE_LOW status, or negative errno on failure.
2329 * This function should be called from contexts where we cannot sleep, and will
2330 * complain if the GPIO chip functions potentially sleep.
2332 int gpiod_get_raw_value(const struct gpio_desc
*desc
)
2334 VALIDATE_DESC(desc
);
2335 /* Should be using gpio_get_value_cansleep() */
2336 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2337 return _gpiod_get_raw_value(desc
);
2339 EXPORT_SYMBOL_GPL(gpiod_get_raw_value
);
2342 * gpiod_get_value() - return a gpio's value
2343 * @desc: gpio whose value will be returned
2345 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2346 * account, or negative errno on failure.
2348 * This function should be called from contexts where we cannot sleep, and will
2349 * complain if the GPIO chip functions potentially sleep.
2351 int gpiod_get_value(const struct gpio_desc
*desc
)
2355 VALIDATE_DESC(desc
);
2356 /* Should be using gpio_get_value_cansleep() */
2357 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2359 value
= _gpiod_get_raw_value(desc
);
2363 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2368 EXPORT_SYMBOL_GPL(gpiod_get_value
);
2371 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2372 * @desc: gpio descriptor whose state need to be set.
2373 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2375 static void _gpio_set_open_drain_value(struct gpio_desc
*desc
, bool value
)
2378 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2379 int offset
= gpio_chip_hwgpio(desc
);
2382 err
= chip
->direction_input(chip
, offset
);
2384 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2386 err
= chip
->direction_output(chip
, offset
, 0);
2388 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2390 trace_gpio_direction(desc_to_gpio(desc
), value
, err
);
2393 "%s: Error in set_value for open drain err %d\n",
2398 * _gpio_set_open_source_value() - Set the open source gpio's value.
2399 * @desc: gpio descriptor whose state need to be set.
2400 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2402 static void _gpio_set_open_source_value(struct gpio_desc
*desc
, bool value
)
2405 struct gpio_chip
*chip
= desc
->gdev
->chip
;
2406 int offset
= gpio_chip_hwgpio(desc
);
2409 err
= chip
->direction_output(chip
, offset
, 1);
2411 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2413 err
= chip
->direction_input(chip
, offset
);
2415 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2417 trace_gpio_direction(desc_to_gpio(desc
), !value
, err
);
2420 "%s: Error in set_value for open source err %d\n",
2424 static void _gpiod_set_raw_value(struct gpio_desc
*desc
, bool value
)
2426 struct gpio_chip
*chip
;
2428 chip
= desc
->gdev
->chip
;
2429 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
2430 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
2431 _gpio_set_open_drain_value(desc
, value
);
2432 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
2433 _gpio_set_open_source_value(desc
, value
);
2435 chip
->set(chip
, gpio_chip_hwgpio(desc
), value
);
2439 * set multiple outputs on the same chip;
2440 * use the chip's set_multiple function if available;
2441 * otherwise set the outputs sequentially;
2442 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2443 * defines which outputs are to be changed
2444 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2445 * defines the values the outputs specified by mask are to be set to
2447 static void gpio_chip_set_multiple(struct gpio_chip
*chip
,
2448 unsigned long *mask
, unsigned long *bits
)
2450 if (chip
->set_multiple
) {
2451 chip
->set_multiple(chip
, mask
, bits
);
2454 for (i
= 0; i
< chip
->ngpio
; i
++) {
2455 if (mask
[BIT_WORD(i
)] == 0) {
2456 /* no more set bits in this mask word;
2457 * skip ahead to the next word */
2458 i
= (BIT_WORD(i
) + 1) * BITS_PER_LONG
- 1;
2461 /* set outputs if the corresponding mask bit is set */
2462 if (__test_and_clear_bit(i
, mask
))
2463 chip
->set(chip
, i
, test_bit(i
, bits
));
2468 void gpiod_set_array_value_complex(bool raw
, bool can_sleep
,
2469 unsigned int array_size
,
2470 struct gpio_desc
**desc_array
,
2475 while (i
< array_size
) {
2476 struct gpio_chip
*chip
= desc_array
[i
]->gdev
->chip
;
2477 unsigned long mask
[BITS_TO_LONGS(chip
->ngpio
)];
2478 unsigned long bits
[BITS_TO_LONGS(chip
->ngpio
)];
2482 WARN_ON(chip
->can_sleep
);
2484 memset(mask
, 0, sizeof(mask
));
2486 struct gpio_desc
*desc
= desc_array
[i
];
2487 int hwgpio
= gpio_chip_hwgpio(desc
);
2488 int value
= value_array
[i
];
2490 if (!raw
&& test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2492 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
2494 * collect all normal outputs belonging to the same chip
2495 * open drain and open source outputs are set individually
2497 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
2498 _gpio_set_open_drain_value(desc
, value
);
2499 } else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
2500 _gpio_set_open_source_value(desc
, value
);
2502 __set_bit(hwgpio
, mask
);
2504 __set_bit(hwgpio
, bits
);
2506 __clear_bit(hwgpio
, bits
);
2510 } while ((i
< array_size
) &&
2511 (desc_array
[i
]->gdev
->chip
== chip
));
2512 /* push collected bits to outputs */
2514 gpio_chip_set_multiple(chip
, mask
, bits
);
2519 * gpiod_set_raw_value() - assign a gpio's raw value
2520 * @desc: gpio whose value will be assigned
2521 * @value: value to assign
2523 * Set the raw value of the GPIO, i.e. the value of its physical line without
2524 * regard for its ACTIVE_LOW status.
2526 * This function should be called from contexts where we cannot sleep, and will
2527 * complain if the GPIO chip functions potentially sleep.
2529 void gpiod_set_raw_value(struct gpio_desc
*desc
, int value
)
2531 VALIDATE_DESC_VOID(desc
);
2532 /* Should be using gpiod_set_value_cansleep() */
2533 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2534 _gpiod_set_raw_value(desc
, value
);
2536 EXPORT_SYMBOL_GPL(gpiod_set_raw_value
);
2539 * gpiod_set_value() - assign a gpio's value
2540 * @desc: gpio whose value will be assigned
2541 * @value: value to assign
2543 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2546 * This function should be called from contexts where we cannot sleep, and will
2547 * complain if the GPIO chip functions potentially sleep.
2549 void gpiod_set_value(struct gpio_desc
*desc
, int value
)
2551 VALIDATE_DESC_VOID(desc
);
2552 /* Should be using gpiod_set_value_cansleep() */
2553 WARN_ON(desc
->gdev
->chip
->can_sleep
);
2554 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2556 _gpiod_set_raw_value(desc
, value
);
2558 EXPORT_SYMBOL_GPL(gpiod_set_value
);
2561 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2562 * @array_size: number of elements in the descriptor / value arrays
2563 * @desc_array: array of GPIO descriptors whose values will be assigned
2564 * @value_array: array of values to assign
2566 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2567 * without regard for their ACTIVE_LOW status.
2569 * This function should be called from contexts where we cannot sleep, and will
2570 * complain if the GPIO chip functions potentially sleep.
2572 void gpiod_set_raw_array_value(unsigned int array_size
,
2573 struct gpio_desc
**desc_array
, int *value_array
)
2577 gpiod_set_array_value_complex(true, false, array_size
, desc_array
,
2580 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value
);
2583 * gpiod_set_array_value() - assign values to an array of GPIOs
2584 * @array_size: number of elements in the descriptor / value arrays
2585 * @desc_array: array of GPIO descriptors whose values will be assigned
2586 * @value_array: array of values to assign
2588 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2591 * This function should be called from contexts where we cannot sleep, and will
2592 * complain if the GPIO chip functions potentially sleep.
2594 void gpiod_set_array_value(unsigned int array_size
,
2595 struct gpio_desc
**desc_array
, int *value_array
)
2599 gpiod_set_array_value_complex(false, false, array_size
, desc_array
,
2602 EXPORT_SYMBOL_GPL(gpiod_set_array_value
);
2605 * gpiod_cansleep() - report whether gpio value access may sleep
2606 * @desc: gpio to check
2609 int gpiod_cansleep(const struct gpio_desc
*desc
)
2611 VALIDATE_DESC(desc
);
2612 return desc
->gdev
->chip
->can_sleep
;
2614 EXPORT_SYMBOL_GPL(gpiod_cansleep
);
2617 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2618 * @desc: gpio whose IRQ will be returned (already requested)
2620 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2623 int gpiod_to_irq(const struct gpio_desc
*desc
)
2625 struct gpio_chip
*chip
;
2629 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2630 * requires this function to not return zero on an invalid descriptor
2631 * but rather a negative error number.
2633 if (!desc
|| IS_ERR(desc
) || !desc
->gdev
|| !desc
->gdev
->chip
)
2636 chip
= desc
->gdev
->chip
;
2637 offset
= gpio_chip_hwgpio(desc
);
2639 int retirq
= chip
->to_irq(chip
, offset
);
2641 /* Zero means NO_IRQ */
2649 EXPORT_SYMBOL_GPL(gpiod_to_irq
);
2652 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2653 * @chip: the chip the GPIO to lock belongs to
2654 * @offset: the offset of the GPIO to lock as IRQ
2656 * This is used directly by GPIO drivers that want to lock down
2657 * a certain GPIO line to be used for IRQs.
2659 int gpiochip_lock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2661 struct gpio_desc
*desc
;
2663 desc
= gpiochip_get_desc(chip
, offset
);
2665 return PTR_ERR(desc
);
2667 /* Flush direction if something changed behind our back */
2668 if (chip
->get_direction
) {
2669 int dir
= chip
->get_direction(chip
, offset
);
2672 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2674 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2677 if (test_bit(FLAG_IS_OUT
, &desc
->flags
)) {
2679 "%s: tried to flag a GPIO set as output for IRQ\n",
2684 set_bit(FLAG_USED_AS_IRQ
, &desc
->flags
);
2687 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq
);
2690 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2691 * @chip: the chip the GPIO to lock belongs to
2692 * @offset: the offset of the GPIO to lock as IRQ
2694 * This is used directly by GPIO drivers that want to indicate
2695 * that a certain GPIO is no longer used exclusively for IRQ.
2697 void gpiochip_unlock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2699 if (offset
>= chip
->ngpio
)
2702 clear_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2704 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq
);
2706 bool gpiochip_line_is_irq(struct gpio_chip
*chip
, unsigned int offset
)
2708 if (offset
>= chip
->ngpio
)
2711 return test_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2713 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq
);
2715 bool gpiochip_line_is_open_drain(struct gpio_chip
*chip
, unsigned int offset
)
2717 if (offset
>= chip
->ngpio
)
2720 return test_bit(FLAG_OPEN_DRAIN
, &chip
->gpiodev
->descs
[offset
].flags
);
2722 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain
);
2724 bool gpiochip_line_is_open_source(struct gpio_chip
*chip
, unsigned int offset
)
2726 if (offset
>= chip
->ngpio
)
2729 return test_bit(FLAG_OPEN_SOURCE
, &chip
->gpiodev
->descs
[offset
].flags
);
2731 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source
);
2734 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2735 * @desc: gpio whose value will be returned
2737 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2738 * its ACTIVE_LOW status, or negative errno on failure.
2740 * This function is to be called from contexts that can sleep.
2742 int gpiod_get_raw_value_cansleep(const struct gpio_desc
*desc
)
2744 might_sleep_if(extra_checks
);
2745 VALIDATE_DESC(desc
);
2746 return _gpiod_get_raw_value(desc
);
2748 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep
);
2751 * gpiod_get_value_cansleep() - return a gpio's value
2752 * @desc: gpio whose value will be returned
2754 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2755 * account, or negative errno on failure.
2757 * This function is to be called from contexts that can sleep.
2759 int gpiod_get_value_cansleep(const struct gpio_desc
*desc
)
2763 might_sleep_if(extra_checks
);
2764 VALIDATE_DESC(desc
);
2765 value
= _gpiod_get_raw_value(desc
);
2769 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2774 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep
);
2777 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2778 * @desc: gpio whose value will be assigned
2779 * @value: value to assign
2781 * Set the raw value of the GPIO, i.e. the value of its physical line without
2782 * regard for its ACTIVE_LOW status.
2784 * This function is to be called from contexts that can sleep.
2786 void gpiod_set_raw_value_cansleep(struct gpio_desc
*desc
, int value
)
2788 might_sleep_if(extra_checks
);
2789 VALIDATE_DESC_VOID(desc
);
2790 _gpiod_set_raw_value(desc
, value
);
2792 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep
);
2795 * gpiod_set_value_cansleep() - assign a gpio's value
2796 * @desc: gpio whose value will be assigned
2797 * @value: value to assign
2799 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2802 * This function is to be called from contexts that can sleep.
2804 void gpiod_set_value_cansleep(struct gpio_desc
*desc
, int value
)
2806 might_sleep_if(extra_checks
);
2807 VALIDATE_DESC_VOID(desc
);
2808 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2810 _gpiod_set_raw_value(desc
, value
);
2812 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep
);
2815 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2816 * @array_size: number of elements in the descriptor / value arrays
2817 * @desc_array: array of GPIO descriptors whose values will be assigned
2818 * @value_array: array of values to assign
2820 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2821 * without regard for their ACTIVE_LOW status.
2823 * This function is to be called from contexts that can sleep.
2825 void gpiod_set_raw_array_value_cansleep(unsigned int array_size
,
2826 struct gpio_desc
**desc_array
,
2829 might_sleep_if(extra_checks
);
2832 gpiod_set_array_value_complex(true, true, array_size
, desc_array
,
2835 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep
);
2838 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2839 * @array_size: number of elements in the descriptor / value arrays
2840 * @desc_array: array of GPIO descriptors whose values will be assigned
2841 * @value_array: array of values to assign
2843 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2846 * This function is to be called from contexts that can sleep.
2848 void gpiod_set_array_value_cansleep(unsigned int array_size
,
2849 struct gpio_desc
**desc_array
,
2852 might_sleep_if(extra_checks
);
2855 gpiod_set_array_value_complex(false, true, array_size
, desc_array
,
2858 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep
);
2861 * gpiod_add_lookup_table() - register GPIO device consumers
2862 * @table: table of consumers to register
2864 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
)
2866 mutex_lock(&gpio_lookup_lock
);
2868 list_add_tail(&table
->list
, &gpio_lookup_list
);
2870 mutex_unlock(&gpio_lookup_lock
);
2874 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2875 * @table: table of consumers to unregister
2877 void gpiod_remove_lookup_table(struct gpiod_lookup_table
*table
)
2879 mutex_lock(&gpio_lookup_lock
);
2881 list_del(&table
->list
);
2883 mutex_unlock(&gpio_lookup_lock
);
2886 static struct gpiod_lookup_table
*gpiod_find_lookup_table(struct device
*dev
)
2888 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
2889 struct gpiod_lookup_table
*table
;
2891 mutex_lock(&gpio_lookup_lock
);
2893 list_for_each_entry(table
, &gpio_lookup_list
, list
) {
2894 if (table
->dev_id
&& dev_id
) {
2896 * Valid strings on both ends, must be identical to have
2899 if (!strcmp(table
->dev_id
, dev_id
))
2903 * One of the pointers is NULL, so both must be to have
2906 if (dev_id
== table
->dev_id
)
2913 mutex_unlock(&gpio_lookup_lock
);
2917 static struct gpio_desc
*gpiod_find(struct device
*dev
, const char *con_id
,
2919 enum gpio_lookup_flags
*flags
)
2921 struct gpio_desc
*desc
= ERR_PTR(-ENOENT
);
2922 struct gpiod_lookup_table
*table
;
2923 struct gpiod_lookup
*p
;
2925 table
= gpiod_find_lookup_table(dev
);
2929 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2930 struct gpio_chip
*chip
;
2932 /* idx must always match exactly */
2936 /* If the lookup entry has a con_id, require exact match */
2937 if (p
->con_id
&& (!con_id
|| strcmp(p
->con_id
, con_id
)))
2940 chip
= find_chip_by_name(p
->chip_label
);
2943 dev_err(dev
, "cannot find GPIO chip %s\n",
2945 return ERR_PTR(-ENODEV
);
2948 if (chip
->ngpio
<= p
->chip_hwnum
) {
2950 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2951 idx
, chip
->ngpio
, chip
->label
);
2952 return ERR_PTR(-EINVAL
);
2955 desc
= gpiochip_get_desc(chip
, p
->chip_hwnum
);
2964 static int dt_gpio_count(struct device
*dev
, const char *con_id
)
2970 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2972 snprintf(propname
, sizeof(propname
), "%s-%s",
2973 con_id
, gpio_suffixes
[i
]);
2975 snprintf(propname
, sizeof(propname
), "%s",
2978 ret
= of_gpio_named_count(dev
->of_node
, propname
);
2985 static int platform_gpio_count(struct device
*dev
, const char *con_id
)
2987 struct gpiod_lookup_table
*table
;
2988 struct gpiod_lookup
*p
;
2989 unsigned int count
= 0;
2991 table
= gpiod_find_lookup_table(dev
);
2995 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2996 if ((con_id
&& p
->con_id
&& !strcmp(con_id
, p
->con_id
)) ||
2997 (!con_id
&& !p
->con_id
))
3007 * gpiod_count - return the number of GPIOs associated with a device / function
3008 * or -ENOENT if no GPIO has been assigned to the requested function
3009 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3010 * @con_id: function within the GPIO consumer
3012 int gpiod_count(struct device
*dev
, const char *con_id
)
3014 int count
= -ENOENT
;
3016 if (IS_ENABLED(CONFIG_OF
) && dev
&& dev
->of_node
)
3017 count
= dt_gpio_count(dev
, con_id
);
3018 else if (IS_ENABLED(CONFIG_ACPI
) && dev
&& ACPI_HANDLE(dev
))
3019 count
= acpi_gpio_count(dev
, con_id
);
3022 count
= platform_gpio_count(dev
, con_id
);
3026 EXPORT_SYMBOL_GPL(gpiod_count
);
3029 * gpiod_get - obtain a GPIO for a given GPIO function
3030 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3031 * @con_id: function within the GPIO consumer
3032 * @flags: optional GPIO initialization flags
3034 * Return the GPIO descriptor corresponding to the function con_id of device
3035 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3036 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3038 struct gpio_desc
*__must_check
gpiod_get(struct device
*dev
, const char *con_id
,
3039 enum gpiod_flags flags
)
3041 return gpiod_get_index(dev
, con_id
, 0, flags
);
3043 EXPORT_SYMBOL_GPL(gpiod_get
);
3046 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3047 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3048 * @con_id: function within the GPIO consumer
3049 * @flags: optional GPIO initialization flags
3051 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3052 * the requested function it will return NULL. This is convenient for drivers
3053 * that need to handle optional GPIOs.
3055 struct gpio_desc
*__must_check
gpiod_get_optional(struct device
*dev
,
3057 enum gpiod_flags flags
)
3059 return gpiod_get_index_optional(dev
, con_id
, 0, flags
);
3061 EXPORT_SYMBOL_GPL(gpiod_get_optional
);
3065 * gpiod_configure_flags - helper function to configure a given GPIO
3066 * @desc: gpio whose value will be assigned
3067 * @con_id: function within the GPIO consumer
3068 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3070 * @dflags: gpiod_flags - optional GPIO initialization flags
3072 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3073 * requested function and/or index, or another IS_ERR() code if an error
3074 * occurred while trying to acquire the GPIO.
3076 static int gpiod_configure_flags(struct gpio_desc
*desc
, const char *con_id
,
3077 unsigned long lflags
, enum gpiod_flags dflags
)
3081 if (lflags
& GPIO_ACTIVE_LOW
)
3082 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
3083 if (lflags
& GPIO_OPEN_DRAIN
)
3084 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
3085 if (lflags
& GPIO_OPEN_SOURCE
)
3086 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
3088 /* No particular flag request, return here... */
3089 if (!(dflags
& GPIOD_FLAGS_BIT_DIR_SET
)) {
3090 pr_debug("no flags found for %s\n", con_id
);
3095 if (dflags
& GPIOD_FLAGS_BIT_DIR_OUT
)
3096 status
= gpiod_direction_output(desc
,
3097 dflags
& GPIOD_FLAGS_BIT_DIR_VAL
);
3099 status
= gpiod_direction_input(desc
);
3105 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3106 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3107 * @con_id: function within the GPIO consumer
3108 * @idx: index of the GPIO to obtain in the consumer
3109 * @flags: optional GPIO initialization flags
3111 * This variant of gpiod_get() allows to access GPIOs other than the first
3112 * defined one for functions that define several GPIOs.
3114 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3115 * requested function and/or index, or another IS_ERR() code if an error
3116 * occurred while trying to acquire the GPIO.
3118 struct gpio_desc
*__must_check
gpiod_get_index(struct device
*dev
,
3121 enum gpiod_flags flags
)
3123 struct gpio_desc
*desc
= NULL
;
3125 enum gpio_lookup_flags lookupflags
= 0;
3127 dev_dbg(dev
, "GPIO lookup for consumer %s\n", con_id
);
3130 /* Using device tree? */
3131 if (IS_ENABLED(CONFIG_OF
) && dev
->of_node
) {
3132 dev_dbg(dev
, "using device tree for GPIO lookup\n");
3133 desc
= of_find_gpio(dev
, con_id
, idx
, &lookupflags
);
3134 } else if (ACPI_COMPANION(dev
)) {
3135 dev_dbg(dev
, "using ACPI for GPIO lookup\n");
3136 desc
= acpi_find_gpio(dev
, con_id
, idx
, flags
, &lookupflags
);
3141 * Either we are not using DT or ACPI, or their lookup did not return
3142 * a result. In that case, use platform lookup as a fallback.
3144 if (!desc
|| desc
== ERR_PTR(-ENOENT
)) {
3145 dev_dbg(dev
, "using lookup tables for GPIO lookup\n");
3146 desc
= gpiod_find(dev
, con_id
, idx
, &lookupflags
);
3150 dev_dbg(dev
, "lookup for GPIO %s failed\n", con_id
);
3154 status
= gpiod_request(desc
, con_id
);
3156 return ERR_PTR(status
);
3158 status
= gpiod_configure_flags(desc
, con_id
, lookupflags
, flags
);
3160 dev_dbg(dev
, "setup of GPIO %s failed\n", con_id
);
3162 return ERR_PTR(status
);
3167 EXPORT_SYMBOL_GPL(gpiod_get_index
);
3170 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3171 * @fwnode: handle of the firmware node
3172 * @propname: name of the firmware property representing the GPIO
3174 * This function can be used for drivers that get their configuration
3177 * Function properly finds the corresponding GPIO using whatever is the
3178 * underlying firmware interface and then makes sure that the GPIO
3179 * descriptor is requested before it is returned to the caller.
3181 * In case of error an ERR_PTR() is returned.
3183 struct gpio_desc
*fwnode_get_named_gpiod(struct fwnode_handle
*fwnode
,
3184 const char *propname
)
3186 struct gpio_desc
*desc
= ERR_PTR(-ENODEV
);
3187 bool active_low
= false;
3188 bool single_ended
= false;
3192 return ERR_PTR(-EINVAL
);
3194 if (is_of_node(fwnode
)) {
3195 enum of_gpio_flags flags
;
3197 desc
= of_get_named_gpiod_flags(to_of_node(fwnode
), propname
, 0,
3199 if (!IS_ERR(desc
)) {
3200 active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
3201 single_ended
= flags
& OF_GPIO_SINGLE_ENDED
;
3203 } else if (is_acpi_node(fwnode
)) {
3204 struct acpi_gpio_info info
;
3206 desc
= acpi_node_get_gpiod(fwnode
, propname
, 0, &info
);
3208 active_low
= info
.polarity
== GPIO_ACTIVE_LOW
;
3214 ret
= gpiod_request(desc
, NULL
);
3216 return ERR_PTR(ret
);
3219 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
3223 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
3225 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
3230 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod
);
3233 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3235 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3236 * @con_id: function within the GPIO consumer
3237 * @index: index of the GPIO to obtain in the consumer
3238 * @flags: optional GPIO initialization flags
3240 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3241 * specified index was assigned to the requested function it will return NULL.
3242 * This is convenient for drivers that need to handle optional GPIOs.
3244 struct gpio_desc
*__must_check
gpiod_get_index_optional(struct device
*dev
,
3247 enum gpiod_flags flags
)
3249 struct gpio_desc
*desc
;
3251 desc
= gpiod_get_index(dev
, con_id
, index
, flags
);
3253 if (PTR_ERR(desc
) == -ENOENT
)
3259 EXPORT_SYMBOL_GPL(gpiod_get_index_optional
);
3262 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3263 * @desc: gpio whose value will be assigned
3264 * @name: gpio line name
3265 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3267 * @dflags: gpiod_flags - optional GPIO initialization flags
3269 int gpiod_hog(struct gpio_desc
*desc
, const char *name
,
3270 unsigned long lflags
, enum gpiod_flags dflags
)
3272 struct gpio_chip
*chip
;
3273 struct gpio_desc
*local_desc
;
3277 chip
= gpiod_to_chip(desc
);
3278 hwnum
= gpio_chip_hwgpio(desc
);
3280 local_desc
= gpiochip_request_own_desc(chip
, hwnum
, name
);
3281 if (IS_ERR(local_desc
)) {
3282 status
= PTR_ERR(local_desc
);
3283 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3284 name
, chip
->label
, hwnum
, status
);
3288 status
= gpiod_configure_flags(desc
, name
, lflags
, dflags
);
3290 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3291 name
, chip
->label
, hwnum
, status
);
3292 gpiochip_free_own_desc(desc
);
3296 /* Mark GPIO as hogged so it can be identified and removed later */
3297 set_bit(FLAG_IS_HOGGED
, &desc
->flags
);
3299 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3300 desc_to_gpio(desc
), name
,
3301 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ? "output" : "input",
3302 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ?
3303 (dflags
&GPIOD_FLAGS_BIT_DIR_VAL
) ? "/high" : "/low":"");
3309 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3310 * @chip: gpio chip to act on
3312 * This is only used by of_gpiochip_remove to free hogged gpios
3314 static void gpiochip_free_hogs(struct gpio_chip
*chip
)
3318 for (id
= 0; id
< chip
->ngpio
; id
++) {
3319 if (test_bit(FLAG_IS_HOGGED
, &chip
->gpiodev
->descs
[id
].flags
))
3320 gpiochip_free_own_desc(&chip
->gpiodev
->descs
[id
]);
3325 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3326 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3327 * @con_id: function within the GPIO consumer
3328 * @flags: optional GPIO initialization flags
3330 * This function acquires all the GPIOs defined under a given function.
3332 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3333 * no GPIO has been assigned to the requested function, or another IS_ERR()
3334 * code if an error occurred while trying to acquire the GPIOs.
3336 struct gpio_descs
*__must_check
gpiod_get_array(struct device
*dev
,
3338 enum gpiod_flags flags
)
3340 struct gpio_desc
*desc
;
3341 struct gpio_descs
*descs
;
3344 count
= gpiod_count(dev
, con_id
);
3346 return ERR_PTR(count
);
3348 descs
= kzalloc(sizeof(*descs
) + sizeof(descs
->desc
[0]) * count
,
3351 return ERR_PTR(-ENOMEM
);
3353 for (descs
->ndescs
= 0; descs
->ndescs
< count
; ) {
3354 desc
= gpiod_get_index(dev
, con_id
, descs
->ndescs
, flags
);
3356 gpiod_put_array(descs
);
3357 return ERR_CAST(desc
);
3359 descs
->desc
[descs
->ndescs
] = desc
;
3364 EXPORT_SYMBOL_GPL(gpiod_get_array
);
3367 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3369 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3370 * @con_id: function within the GPIO consumer
3371 * @flags: optional GPIO initialization flags
3373 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3374 * assigned to the requested function it will return NULL.
3376 struct gpio_descs
*__must_check
gpiod_get_array_optional(struct device
*dev
,
3378 enum gpiod_flags flags
)
3380 struct gpio_descs
*descs
;
3382 descs
= gpiod_get_array(dev
, con_id
, flags
);
3383 if (IS_ERR(descs
) && (PTR_ERR(descs
) == -ENOENT
))
3388 EXPORT_SYMBOL_GPL(gpiod_get_array_optional
);
3391 * gpiod_put - dispose of a GPIO descriptor
3392 * @desc: GPIO descriptor to dispose of
3394 * No descriptor can be used after gpiod_put() has been called on it.
3396 void gpiod_put(struct gpio_desc
*desc
)
3400 EXPORT_SYMBOL_GPL(gpiod_put
);
3403 * gpiod_put_array - dispose of multiple GPIO descriptors
3404 * @descs: struct gpio_descs containing an array of descriptors
3406 void gpiod_put_array(struct gpio_descs
*descs
)
3410 for (i
= 0; i
< descs
->ndescs
; i
++)
3411 gpiod_put(descs
->desc
[i
]);
3415 EXPORT_SYMBOL_GPL(gpiod_put_array
);
3417 static int __init
gpiolib_dev_init(void)
3421 /* Register GPIO sysfs bus */
3422 ret
= bus_register(&gpio_bus_type
);
3424 pr_err("gpiolib: could not register GPIO bus type\n");
3428 ret
= alloc_chrdev_region(&gpio_devt
, 0, GPIO_DEV_MAX
, "gpiochip");
3430 pr_err("gpiolib: failed to allocate char dev region\n");
3431 bus_unregister(&gpio_bus_type
);
3433 gpiolib_initialized
= true;
3434 gpiochip_setup_devs();
3438 core_initcall(gpiolib_dev_init
);
3440 #ifdef CONFIG_DEBUG_FS
3442 static void gpiolib_dbg_show(struct seq_file
*s
, struct gpio_device
*gdev
)
3445 struct gpio_chip
*chip
= gdev
->chip
;
3446 unsigned gpio
= gdev
->base
;
3447 struct gpio_desc
*gdesc
= &gdev
->descs
[0];
3451 for (i
= 0; i
< gdev
->ngpio
; i
++, gpio
++, gdesc
++) {
3452 if (!test_bit(FLAG_REQUESTED
, &gdesc
->flags
)) {
3454 seq_printf(s
, " gpio-%-3d (%-20.20s)\n",
3460 gpiod_get_direction(gdesc
);
3461 is_out
= test_bit(FLAG_IS_OUT
, &gdesc
->flags
);
3462 is_irq
= test_bit(FLAG_USED_AS_IRQ
, &gdesc
->flags
);
3463 seq_printf(s
, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3464 gpio
, gdesc
->name
? gdesc
->name
: "", gdesc
->label
,
3465 is_out
? "out" : "in ",
3467 ? (chip
->get(chip
, i
) ? "hi" : "lo")
3469 is_irq
? "IRQ" : " ");
3470 seq_printf(s
, "\n");
3474 static void *gpiolib_seq_start(struct seq_file
*s
, loff_t
*pos
)
3476 unsigned long flags
;
3477 struct gpio_device
*gdev
= NULL
;
3478 loff_t index
= *pos
;
3482 spin_lock_irqsave(&gpio_lock
, flags
);
3483 list_for_each_entry(gdev
, &gpio_devices
, list
)
3485 spin_unlock_irqrestore(&gpio_lock
, flags
);
3488 spin_unlock_irqrestore(&gpio_lock
, flags
);
3493 static void *gpiolib_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
3495 unsigned long flags
;
3496 struct gpio_device
*gdev
= v
;
3499 spin_lock_irqsave(&gpio_lock
, flags
);
3500 if (list_is_last(&gdev
->list
, &gpio_devices
))
3503 ret
= list_entry(gdev
->list
.next
, struct gpio_device
, list
);
3504 spin_unlock_irqrestore(&gpio_lock
, flags
);
3512 static void gpiolib_seq_stop(struct seq_file
*s
, void *v
)
3516 static int gpiolib_seq_show(struct seq_file
*s
, void *v
)
3518 struct gpio_device
*gdev
= v
;
3519 struct gpio_chip
*chip
= gdev
->chip
;
3520 struct device
*parent
;
3523 seq_printf(s
, "%s%s: (dangling chip)", (char *)s
->private,
3524 dev_name(&gdev
->dev
));
3528 seq_printf(s
, "%s%s: GPIOs %d-%d", (char *)s
->private,
3529 dev_name(&gdev
->dev
),
3530 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1);
3531 parent
= chip
->parent
;
3533 seq_printf(s
, ", parent: %s/%s",
3534 parent
->bus
? parent
->bus
->name
: "no-bus",
3537 seq_printf(s
, ", %s", chip
->label
);
3538 if (chip
->can_sleep
)
3539 seq_printf(s
, ", can sleep");
3540 seq_printf(s
, ":\n");
3543 chip
->dbg_show(s
, chip
);
3545 gpiolib_dbg_show(s
, gdev
);
3550 static const struct seq_operations gpiolib_seq_ops
= {
3551 .start
= gpiolib_seq_start
,
3552 .next
= gpiolib_seq_next
,
3553 .stop
= gpiolib_seq_stop
,
3554 .show
= gpiolib_seq_show
,
3557 static int gpiolib_open(struct inode
*inode
, struct file
*file
)
3559 return seq_open(file
, &gpiolib_seq_ops
);
3562 static const struct file_operations gpiolib_operations
= {
3563 .owner
= THIS_MODULE
,
3564 .open
= gpiolib_open
,
3566 .llseek
= seq_lseek
,
3567 .release
= seq_release
,
3570 static int __init
gpiolib_debugfs_init(void)
3572 /* /sys/kernel/debug/gpio */
3573 (void) debugfs_create_file("gpio", S_IFREG
| S_IRUGO
,
3574 NULL
, NULL
, &gpiolib_operations
);
3577 subsys_initcall(gpiolib_debugfs_init
);
3579 #endif /* DEBUG_FS */