1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bitmap.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/interrupt.h>
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/debugfs.h>
12 #include <linux/seq_file.h>
13 #include <linux/gpio.h>
14 #include <linux/of_gpio.h>
15 #include <linux/idr.h>
16 #include <linux/slab.h>
17 #include <linux/acpi.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/gpio/machine.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/cdev.h>
23 #include <linux/uaccess.h>
24 #include <linux/compat.h>
25 #include <linux/anon_inodes.h>
26 #include <linux/file.h>
27 #include <linux/kfifo.h>
28 #include <linux/poll.h>
29 #include <linux/timekeeping.h>
30 #include <uapi/linux/gpio.h>
34 #define CREATE_TRACE_POINTS
35 #include <trace/events/gpio.h>
37 /* Implementation infrastructure for GPIO interfaces.
39 * The GPIO programming interface allows for inlining speed-critical
40 * get/set operations for common cases, so that access to SOC-integrated
41 * GPIOs can sometimes cost only an instruction or two per bit.
45 /* When debugging, extend minimal trust to callers and platform code.
46 * Also emit diagnostic messages that may help initial bringup, when
47 * board setup or driver bugs are most common.
49 * Otherwise, minimize overhead in what may be bitbanging codepaths.
52 #define extra_checks 1
54 #define extra_checks 0
57 /* Device and char device-related information */
58 static DEFINE_IDA(gpio_ida);
59 static dev_t gpio_devt;
60 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
61 static struct bus_type gpio_bus_type = {
66 * Number of GPIOs to use for the fast path in set array
68 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
70 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
71 * While any GPIO is requested, its gpio_chip is not removable;
72 * each GPIO's "requested" flag serves as a lock and refcount.
74 DEFINE_SPINLOCK(gpio_lock);
76 static DEFINE_MUTEX(gpio_lookup_lock);
77 static LIST_HEAD(gpio_lookup_list);
78 LIST_HEAD(gpio_devices);
80 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
81 static LIST_HEAD(gpio_machine_hogs);
83 static void gpiochip_free_hogs(struct gpio_chip *chip);
84 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
85 struct lock_class_key *lock_key,
86 struct lock_class_key *request_key);
87 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
88 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
89 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
91 static bool gpiolib_initialized;
93 static inline void desc_set_label(struct gpio_desc *d, const char *label)
99 * gpio_to_desc - Convert a GPIO number to its descriptor
100 * @gpio: global GPIO number
103 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
104 * with the given number exists in the system.
106 struct gpio_desc *gpio_to_desc(unsigned gpio)
108 struct gpio_device *gdev;
111 spin_lock_irqsave(&gpio_lock, flags);
113 list_for_each_entry(gdev, &gpio_devices, list) {
114 if (gdev->base <= gpio &&
115 gdev->base + gdev->ngpio > gpio) {
116 spin_unlock_irqrestore(&gpio_lock, flags);
117 return &gdev->descs[gpio - gdev->base];
121 spin_unlock_irqrestore(&gpio_lock, flags);
123 if (!gpio_is_valid(gpio))
124 WARN(1, "invalid GPIO %d\n", gpio);
128 EXPORT_SYMBOL_GPL(gpio_to_desc);
131 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
132 * hardware number for this chip
134 * @hwnum: hardware number of the GPIO for this chip
137 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
138 * in the given chip for the specified hardware number.
140 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
143 struct gpio_device *gdev = chip->gpiodev;
145 if (hwnum >= gdev->ngpio)
146 return ERR_PTR(-EINVAL);
148 return &gdev->descs[hwnum];
152 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
153 * @desc: GPIO descriptor
155 * This should disappear in the future but is needed since we still
156 * use GPIO numbers for error messages and sysfs nodes.
159 * The global GPIO number for the GPIO specified by its descriptor.
161 int desc_to_gpio(const struct gpio_desc *desc)
163 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
165 EXPORT_SYMBOL_GPL(desc_to_gpio);
169 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
170 * @desc: descriptor to return the chip of
172 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
174 if (!desc || !desc->gdev)
176 return desc->gdev->chip;
178 EXPORT_SYMBOL_GPL(gpiod_to_chip);
180 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
181 static int gpiochip_find_base(int ngpio)
183 struct gpio_device *gdev;
184 int base = ARCH_NR_GPIOS - ngpio;
186 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
187 /* found a free space? */
188 if (gdev->base + gdev->ngpio <= base)
191 /* nope, check the space right before the chip */
192 base = gdev->base - ngpio;
195 if (gpio_is_valid(base)) {
196 pr_debug("%s: found new base at %d\n", __func__, base);
199 pr_err("%s: cannot find free range\n", __func__);
205 * gpiod_get_direction - return the current direction of a GPIO
206 * @desc: GPIO to get the direction of
208 * Returns 0 for output, 1 for input, or an error code in case of error.
210 * This function may sleep if gpiod_cansleep() is true.
212 int gpiod_get_direction(struct gpio_desc *desc)
214 struct gpio_chip *chip;
218 chip = gpiod_to_chip(desc);
219 offset = gpio_chip_hwgpio(desc);
221 if (!chip->get_direction)
224 status = chip->get_direction(chip, offset);
226 /* GPIOF_DIR_IN, or other positive */
228 clear_bit(FLAG_IS_OUT, &desc->flags);
232 set_bit(FLAG_IS_OUT, &desc->flags);
236 EXPORT_SYMBOL_GPL(gpiod_get_direction);
239 * Add a new chip to the global chips list, keeping the list of chips sorted
240 * by range(means [base, base + ngpio - 1]) order.
242 * Return -EBUSY if the new chip overlaps with some other chip's integer
245 static int gpiodev_add_to_list(struct gpio_device *gdev)
247 struct gpio_device *prev, *next;
249 if (list_empty(&gpio_devices)) {
250 /* initial entry in list */
251 list_add_tail(&gdev->list, &gpio_devices);
255 next = list_entry(gpio_devices.next, struct gpio_device, list);
256 if (gdev->base + gdev->ngpio <= next->base) {
257 /* add before first entry */
258 list_add(&gdev->list, &gpio_devices);
262 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
263 if (prev->base + prev->ngpio <= gdev->base) {
264 /* add behind last entry */
265 list_add_tail(&gdev->list, &gpio_devices);
269 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
270 /* at the end of the list */
271 if (&next->list == &gpio_devices)
274 /* add between prev and next */
275 if (prev->base + prev->ngpio <= gdev->base
276 && gdev->base + gdev->ngpio <= next->base) {
277 list_add(&gdev->list, &prev->list);
282 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
287 * Convert a GPIO name to its descriptor
289 static struct gpio_desc *gpio_name_to_desc(const char * const name)
291 struct gpio_device *gdev;
294 spin_lock_irqsave(&gpio_lock, flags);
296 list_for_each_entry(gdev, &gpio_devices, list) {
299 for (i = 0; i != gdev->ngpio; ++i) {
300 struct gpio_desc *desc = &gdev->descs[i];
302 if (!desc->name || !name)
305 if (!strcmp(desc->name, name)) {
306 spin_unlock_irqrestore(&gpio_lock, flags);
312 spin_unlock_irqrestore(&gpio_lock, flags);
318 * Takes the names from gc->names and checks if they are all unique. If they
319 * are, they are assigned to their gpio descriptors.
321 * Warning if one of the names is already used for a different GPIO.
323 static int gpiochip_set_desc_names(struct gpio_chip *gc)
325 struct gpio_device *gdev = gc->gpiodev;
331 /* First check all names if they are unique */
332 for (i = 0; i != gc->ngpio; ++i) {
333 struct gpio_desc *gpio;
335 gpio = gpio_name_to_desc(gc->names[i]);
338 "Detected name collision for GPIO name '%s'\n",
342 /* Then add all names to the GPIO descriptors */
343 for (i = 0; i != gc->ngpio; ++i)
344 gdev->descs[i].name = gc->names[i];
349 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
353 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
357 /* Assume by default all GPIOs are valid */
358 bitmap_fill(p, chip->ngpio);
363 static int gpiochip_alloc_valid_mask(struct gpio_chip *gpiochip)
365 #ifdef CONFIG_OF_GPIO
367 struct device_node *np = gpiochip->of_node;
369 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
370 if (size > 0 && size % 2 == 0)
371 gpiochip->need_valid_mask = true;
374 if (!gpiochip->need_valid_mask)
377 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
378 if (!gpiochip->valid_mask)
384 static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
386 if (gpiochip->init_valid_mask)
387 return gpiochip->init_valid_mask(gpiochip);
392 static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
394 kfree(gpiochip->valid_mask);
395 gpiochip->valid_mask = NULL;
398 bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
401 /* No mask means all valid */
402 if (likely(!gpiochip->valid_mask))
404 return test_bit(offset, gpiochip->valid_mask);
406 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
409 * GPIO line handle management
413 * struct linehandle_state - contains the state of a userspace handle
414 * @gdev: the GPIO device the handle pertains to
415 * @label: consumer label used to tag descriptors
416 * @descs: the GPIO descriptors held by this handle
417 * @numdescs: the number of descriptors held in the descs array
419 struct linehandle_state {
420 struct gpio_device *gdev;
422 struct gpio_desc *descs[GPIOHANDLES_MAX];
426 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
427 (GPIOHANDLE_REQUEST_INPUT | \
428 GPIOHANDLE_REQUEST_OUTPUT | \
429 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
430 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
431 GPIOHANDLE_REQUEST_OPEN_SOURCE)
433 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
436 struct linehandle_state *lh = filep->private_data;
437 void __user *ip = (void __user *)arg;
438 struct gpiohandle_data ghd;
439 DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
442 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
443 /* NOTE: It's ok to read values of output lines. */
444 int ret = gpiod_get_array_value_complex(false,
453 memset(&ghd, 0, sizeof(ghd));
454 for (i = 0; i < lh->numdescs; i++)
455 ghd.values[i] = test_bit(i, vals);
457 if (copy_to_user(ip, &ghd, sizeof(ghd)))
461 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
463 * All line descriptors were created at once with the same
464 * flags so just check if the first one is really output.
466 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
469 if (copy_from_user(&ghd, ip, sizeof(ghd)))
472 /* Clamp all values to [0,1] */
473 for (i = 0; i < lh->numdescs; i++)
474 __assign_bit(i, vals, ghd.values[i]);
476 /* Reuse the array setting function */
477 return gpiod_set_array_value_complex(false,
488 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
491 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
495 static int linehandle_release(struct inode *inode, struct file *filep)
497 struct linehandle_state *lh = filep->private_data;
498 struct gpio_device *gdev = lh->gdev;
501 for (i = 0; i < lh->numdescs; i++)
502 gpiod_free(lh->descs[i]);
505 put_device(&gdev->dev);
509 static const struct file_operations linehandle_fileops = {
510 .release = linehandle_release,
511 .owner = THIS_MODULE,
512 .llseek = noop_llseek,
513 .unlocked_ioctl = linehandle_ioctl,
515 .compat_ioctl = linehandle_ioctl_compat,
519 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
521 struct gpiohandle_request handlereq;
522 struct linehandle_state *lh;
524 int fd, i, count = 0, ret;
527 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
529 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
532 lflags = handlereq.flags;
534 /* Return an error if an unknown flag is set */
535 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
539 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
540 * the hardware actually supports enabling both at the same time the
541 * electrical result would be disastrous.
543 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
544 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
547 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
548 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
549 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
550 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
553 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
557 get_device(&gdev->dev);
559 /* Make sure this is terminated */
560 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
561 if (strlen(handlereq.consumer_label)) {
562 lh->label = kstrdup(handlereq.consumer_label,
570 /* Request each GPIO */
571 for (i = 0; i < handlereq.lines; i++) {
572 u32 offset = handlereq.lineoffsets[i];
573 struct gpio_desc *desc;
575 if (offset >= gdev->ngpio) {
580 desc = &gdev->descs[offset];
581 ret = gpiod_request(desc, lh->label);
587 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
588 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
589 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
590 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
591 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
592 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
594 ret = gpiod_set_transitory(desc, false);
599 * Lines have to be requested explicitly for input
600 * or output, else the line will be treated "as is".
602 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
603 int val = !!handlereq.default_values[i];
605 ret = gpiod_direction_output(desc, val);
608 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
609 ret = gpiod_direction_input(desc);
613 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
616 /* Let i point at the last handle */
618 lh->numdescs = handlereq.lines;
620 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
626 file = anon_inode_getfile("gpio-linehandle",
629 O_RDONLY | O_CLOEXEC);
632 goto out_put_unused_fd;
636 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
638 * fput() will trigger the release() callback, so do not go onto
639 * the regular error cleanup path here.
646 fd_install(fd, file);
648 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
656 for (i = 0; i < count; i++)
657 gpiod_free(lh->descs[i]);
661 put_device(&gdev->dev);
666 * GPIO line event management
670 * struct lineevent_state - contains the state of a userspace event
671 * @gdev: the GPIO device the event pertains to
672 * @label: consumer label used to tag descriptors
673 * @desc: the GPIO descriptor held by this event
674 * @eflags: the event flags this line was requested with
675 * @irq: the interrupt that trigger in response to events on this GPIO
676 * @wait: wait queue that handles blocking reads of events
677 * @events: KFIFO for the GPIO events
678 * @read_lock: mutex lock to protect reads from colliding with adding
679 * new events to the FIFO
680 * @timestamp: cache for the timestamp storing it between hardirq
681 * and IRQ thread, used to bring the timestamp close to the actual
684 struct lineevent_state {
685 struct gpio_device *gdev;
687 struct gpio_desc *desc;
690 wait_queue_head_t wait;
691 DECLARE_KFIFO(events, struct gpioevent_data, 16);
692 struct mutex read_lock;
696 #define GPIOEVENT_REQUEST_VALID_FLAGS \
697 (GPIOEVENT_REQUEST_RISING_EDGE | \
698 GPIOEVENT_REQUEST_FALLING_EDGE)
700 static __poll_t lineevent_poll(struct file *filep,
701 struct poll_table_struct *wait)
703 struct lineevent_state *le = filep->private_data;
706 poll_wait(filep, &le->wait, wait);
708 if (!kfifo_is_empty(&le->events))
709 events = EPOLLIN | EPOLLRDNORM;
715 static ssize_t lineevent_read(struct file *filep,
720 struct lineevent_state *le = filep->private_data;
724 if (count < sizeof(struct gpioevent_data))
728 if (kfifo_is_empty(&le->events)) {
729 if (filep->f_flags & O_NONBLOCK)
732 ret = wait_event_interruptible(le->wait,
733 !kfifo_is_empty(&le->events));
738 if (mutex_lock_interruptible(&le->read_lock))
740 ret = kfifo_to_user(&le->events, buf, count, &copied);
741 mutex_unlock(&le->read_lock);
747 * If we couldn't read anything from the fifo (a different
748 * thread might have been faster) we either return -EAGAIN if
749 * the file descriptor is non-blocking, otherwise we go back to
750 * sleep and wait for more data to arrive.
752 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
755 } while (copied == 0);
760 static int lineevent_release(struct inode *inode, struct file *filep)
762 struct lineevent_state *le = filep->private_data;
763 struct gpio_device *gdev = le->gdev;
765 free_irq(le->irq, le);
766 gpiod_free(le->desc);
769 put_device(&gdev->dev);
773 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
776 struct lineevent_state *le = filep->private_data;
777 void __user *ip = (void __user *)arg;
778 struct gpiohandle_data ghd;
781 * We can get the value for an event line but not set it,
782 * because it is input by definition.
784 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
787 memset(&ghd, 0, sizeof(ghd));
789 val = gpiod_get_value_cansleep(le->desc);
794 if (copy_to_user(ip, &ghd, sizeof(ghd)))
803 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
806 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
810 static const struct file_operations lineevent_fileops = {
811 .release = lineevent_release,
812 .read = lineevent_read,
813 .poll = lineevent_poll,
814 .owner = THIS_MODULE,
815 .llseek = noop_llseek,
816 .unlocked_ioctl = lineevent_ioctl,
818 .compat_ioctl = lineevent_ioctl_compat,
822 static irqreturn_t lineevent_irq_thread(int irq, void *p)
824 struct lineevent_state *le = p;
825 struct gpioevent_data ge;
828 /* Do not leak kernel stack to userspace */
829 memset(&ge, 0, sizeof(ge));
832 * We may be running from a nested threaded interrupt in which case
833 * we didn't get the timestamp from lineevent_irq_handler().
836 ge.timestamp = ktime_get_real_ns();
838 ge.timestamp = le->timestamp;
840 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
841 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
842 int level = gpiod_get_value_cansleep(le->desc);
844 /* Emit low-to-high event */
845 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
847 /* Emit high-to-low event */
848 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
849 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
850 /* Emit low-to-high event */
851 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
852 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
853 /* Emit high-to-low event */
854 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
859 ret = kfifo_put(&le->events, ge);
861 wake_up_poll(&le->wait, EPOLLIN);
866 static irqreturn_t lineevent_irq_handler(int irq, void *p)
868 struct lineevent_state *le = p;
871 * Just store the timestamp in hardirq context so we get it as
872 * close in time as possible to the actual event.
874 le->timestamp = ktime_get_real_ns();
876 return IRQ_WAKE_THREAD;
879 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
881 struct gpioevent_request eventreq;
882 struct lineevent_state *le;
883 struct gpio_desc *desc;
892 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
895 le = kzalloc(sizeof(*le), GFP_KERNEL);
899 get_device(&gdev->dev);
901 /* Make sure this is terminated */
902 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
903 if (strlen(eventreq.consumer_label)) {
904 le->label = kstrdup(eventreq.consumer_label,
912 offset = eventreq.lineoffset;
913 lflags = eventreq.handleflags;
914 eflags = eventreq.eventflags;
916 if (offset >= gdev->ngpio) {
921 /* Return an error if a unknown flag is set */
922 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
923 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
928 /* This is just wrong: we don't look for events on output lines */
929 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
934 desc = &gdev->descs[offset];
935 ret = gpiod_request(desc, le->label);
941 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
942 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
943 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
944 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
945 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
946 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
948 ret = gpiod_direction_input(desc);
952 le->irq = gpiod_to_irq(desc);
958 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
959 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
960 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
961 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
962 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
963 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
964 irqflags |= IRQF_ONESHOT;
966 INIT_KFIFO(le->events);
967 init_waitqueue_head(&le->wait);
968 mutex_init(&le->read_lock);
970 /* Request a thread to read the events */
971 ret = request_threaded_irq(le->irq,
972 lineevent_irq_handler,
973 lineevent_irq_thread,
980 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
986 file = anon_inode_getfile("gpio-event",
989 O_RDONLY | O_CLOEXEC);
992 goto out_put_unused_fd;
996 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
998 * fput() will trigger the release() callback, so do not go onto
999 * the regular error cleanup path here.
1006 fd_install(fd, file);
1013 free_irq(le->irq, le);
1015 gpiod_free(le->desc);
1020 put_device(&gdev->dev);
1025 * gpio_ioctl() - ioctl handler for the GPIO chardev
1027 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1029 struct gpio_device *gdev = filp->private_data;
1030 struct gpio_chip *chip = gdev->chip;
1031 void __user *ip = (void __user *)arg;
1033 /* We fail any subsequent ioctl():s when the chip is gone */
1037 /* Fill in the struct and pass to userspace */
1038 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1039 struct gpiochip_info chipinfo;
1041 memset(&chipinfo, 0, sizeof(chipinfo));
1043 strncpy(chipinfo.name, dev_name(&gdev->dev),
1044 sizeof(chipinfo.name));
1045 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1046 strncpy(chipinfo.label, gdev->label,
1047 sizeof(chipinfo.label));
1048 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1049 chipinfo.lines = gdev->ngpio;
1050 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1053 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1054 struct gpioline_info lineinfo;
1055 struct gpio_desc *desc;
1057 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1059 if (lineinfo.line_offset >= gdev->ngpio)
1062 desc = &gdev->descs[lineinfo.line_offset];
1064 strncpy(lineinfo.name, desc->name,
1065 sizeof(lineinfo.name));
1066 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1068 lineinfo.name[0] = '\0';
1071 strncpy(lineinfo.consumer, desc->label,
1072 sizeof(lineinfo.consumer));
1073 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1075 lineinfo.consumer[0] = '\0';
1079 * Userspace only need to know that the kernel is using
1080 * this GPIO so it can't use it.
1083 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1084 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1085 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1086 test_bit(FLAG_EXPORT, &desc->flags) ||
1087 test_bit(FLAG_SYSFS, &desc->flags))
1088 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1089 if (test_bit(FLAG_IS_OUT, &desc->flags))
1090 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1091 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1092 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1093 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1094 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1095 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1096 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1098 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1101 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1102 return linehandle_create(gdev, ip);
1103 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1104 return lineevent_create(gdev, ip);
1109 #ifdef CONFIG_COMPAT
1110 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1113 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1118 * gpio_chrdev_open() - open the chardev for ioctl operations
1119 * @inode: inode for this chardev
1120 * @filp: file struct for storing private data
1121 * Returns 0 on success
1123 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1125 struct gpio_device *gdev = container_of(inode->i_cdev,
1126 struct gpio_device, chrdev);
1128 /* Fail on open if the backing gpiochip is gone */
1131 get_device(&gdev->dev);
1132 filp->private_data = gdev;
1134 return nonseekable_open(inode, filp);
1138 * gpio_chrdev_release() - close chardev after ioctl operations
1139 * @inode: inode for this chardev
1140 * @filp: file struct for storing private data
1141 * Returns 0 on success
1143 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1145 struct gpio_device *gdev = container_of(inode->i_cdev,
1146 struct gpio_device, chrdev);
1148 put_device(&gdev->dev);
1153 static const struct file_operations gpio_fileops = {
1154 .release = gpio_chrdev_release,
1155 .open = gpio_chrdev_open,
1156 .owner = THIS_MODULE,
1157 .llseek = no_llseek,
1158 .unlocked_ioctl = gpio_ioctl,
1159 #ifdef CONFIG_COMPAT
1160 .compat_ioctl = gpio_ioctl_compat,
1164 static void gpiodevice_release(struct device *dev)
1166 struct gpio_device *gdev = dev_get_drvdata(dev);
1168 list_del(&gdev->list);
1169 ida_simple_remove(&gpio_ida, gdev->id);
1170 kfree_const(gdev->label);
1175 static int gpiochip_setup_dev(struct gpio_device *gdev)
1179 cdev_init(&gdev->chrdev, &gpio_fileops);
1180 gdev->chrdev.owner = THIS_MODULE;
1181 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1183 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1187 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1188 MAJOR(gpio_devt), gdev->id);
1190 status = gpiochip_sysfs_register(gdev);
1192 goto err_remove_device;
1194 /* From this point, the .release() function cleans up gpio_device */
1195 gdev->dev.release = gpiodevice_release;
1196 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1197 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1198 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1203 cdev_device_del(&gdev->chrdev, &gdev->dev);
1207 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1209 struct gpio_desc *desc;
1212 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1214 pr_err("%s: unable to get GPIO desc: %ld\n",
1215 __func__, PTR_ERR(desc));
1219 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1222 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1224 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1225 __func__, chip->label, hog->chip_hwnum, rv);
1228 static void machine_gpiochip_add(struct gpio_chip *chip)
1230 struct gpiod_hog *hog;
1232 mutex_lock(&gpio_machine_hogs_mutex);
1234 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1235 if (!strcmp(chip->label, hog->chip_label))
1236 gpiochip_machine_hog(chip, hog);
1239 mutex_unlock(&gpio_machine_hogs_mutex);
1242 static void gpiochip_setup_devs(void)
1244 struct gpio_device *gdev;
1247 list_for_each_entry(gdev, &gpio_devices, list) {
1248 err = gpiochip_setup_dev(gdev);
1250 pr_err("%s: Failed to initialize gpio device (%d)\n",
1251 dev_name(&gdev->dev), err);
1255 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1256 struct lock_class_key *lock_key,
1257 struct lock_class_key *request_key)
1259 unsigned long flags;
1262 int base = chip->base;
1263 struct gpio_device *gdev;
1266 * First: allocate and populate the internal stat container, and
1267 * set up the struct device.
1269 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1272 gdev->dev.bus = &gpio_bus_type;
1274 chip->gpiodev = gdev;
1276 gdev->dev.parent = chip->parent;
1277 gdev->dev.of_node = chip->parent->of_node;
1280 #ifdef CONFIG_OF_GPIO
1281 /* If the gpiochip has an assigned OF node this takes precedence */
1283 gdev->dev.of_node = chip->of_node;
1285 chip->of_node = gdev->dev.of_node;
1288 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1293 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1294 device_initialize(&gdev->dev);
1295 dev_set_drvdata(&gdev->dev, gdev);
1296 if (chip->parent && chip->parent->driver)
1297 gdev->owner = chip->parent->driver->owner;
1298 else if (chip->owner)
1299 /* TODO: remove chip->owner */
1300 gdev->owner = chip->owner;
1302 gdev->owner = THIS_MODULE;
1304 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1310 if (chip->ngpio == 0) {
1311 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1313 goto err_free_descs;
1316 if (chip->ngpio > FASTPATH_NGPIO)
1317 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1318 chip->ngpio, FASTPATH_NGPIO);
1320 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1323 goto err_free_descs;
1326 gdev->ngpio = chip->ngpio;
1329 spin_lock_irqsave(&gpio_lock, flags);
1332 * TODO: this allocates a Linux GPIO number base in the global
1333 * GPIO numberspace for this chip. In the long run we want to
1334 * get *rid* of this numberspace and use only descriptors, but
1335 * it may be a pipe dream. It will not happen before we get rid
1336 * of the sysfs interface anyways.
1339 base = gpiochip_find_base(chip->ngpio);
1342 spin_unlock_irqrestore(&gpio_lock, flags);
1343 goto err_free_label;
1346 * TODO: it should not be necessary to reflect the assigned
1347 * base outside of the GPIO subsystem. Go over drivers and
1348 * see if anyone makes use of this, else drop this and assign
1355 status = gpiodev_add_to_list(gdev);
1357 spin_unlock_irqrestore(&gpio_lock, flags);
1358 goto err_free_label;
1361 spin_unlock_irqrestore(&gpio_lock, flags);
1363 for (i = 0; i < chip->ngpio; i++)
1364 gdev->descs[i].gdev = gdev;
1366 #ifdef CONFIG_PINCTRL
1367 INIT_LIST_HEAD(&gdev->pin_ranges);
1370 status = gpiochip_set_desc_names(chip);
1372 goto err_remove_from_list;
1374 status = gpiochip_irqchip_init_valid_mask(chip);
1376 goto err_remove_from_list;
1378 status = gpiochip_alloc_valid_mask(chip);
1380 goto err_remove_irqchip_mask;
1382 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1384 goto err_free_gpiochip_mask;
1386 status = of_gpiochip_add(chip);
1388 goto err_remove_chip;
1390 status = gpiochip_init_valid_mask(chip);
1392 goto err_remove_of_chip;
1394 for (i = 0; i < chip->ngpio; i++) {
1395 struct gpio_desc *desc = &gdev->descs[i];
1397 if (chip->get_direction && gpiochip_line_is_valid(chip, i)) {
1398 if (!chip->get_direction(chip, i))
1399 set_bit(FLAG_IS_OUT, &desc->flags);
1401 clear_bit(FLAG_IS_OUT, &desc->flags);
1403 if (!chip->direction_input)
1404 set_bit(FLAG_IS_OUT, &desc->flags);
1406 clear_bit(FLAG_IS_OUT, &desc->flags);
1410 acpi_gpiochip_add(chip);
1412 machine_gpiochip_add(chip);
1415 * By first adding the chardev, and then adding the device,
1416 * we get a device node entry in sysfs under
1417 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1418 * coldplug of device nodes and other udev business.
1419 * We can do this only if gpiolib has been initialized.
1420 * Otherwise, defer until later.
1422 if (gpiolib_initialized) {
1423 status = gpiochip_setup_dev(gdev);
1425 goto err_remove_acpi_chip;
1429 err_remove_acpi_chip:
1430 acpi_gpiochip_remove(chip);
1432 gpiochip_free_hogs(chip);
1433 of_gpiochip_remove(chip);
1435 gpiochip_irqchip_remove(chip);
1436 err_free_gpiochip_mask:
1437 gpiochip_free_valid_mask(chip);
1438 err_remove_irqchip_mask:
1439 gpiochip_irqchip_free_valid_mask(chip);
1440 err_remove_from_list:
1441 spin_lock_irqsave(&gpio_lock, flags);
1442 list_del(&gdev->list);
1443 spin_unlock_irqrestore(&gpio_lock, flags);
1445 kfree_const(gdev->label);
1449 ida_simple_remove(&gpio_ida, gdev->id);
1451 /* failures here can mean systems won't boot... */
1452 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1453 gdev->base, gdev->base + gdev->ngpio - 1,
1454 chip->label ? : "generic", status);
1458 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1461 * gpiochip_get_data() - get per-subdriver data for the chip
1465 * The per-subdriver data for the chip.
1467 void *gpiochip_get_data(struct gpio_chip *chip)
1469 return chip->gpiodev->data;
1471 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1474 * gpiochip_remove() - unregister a gpio_chip
1475 * @chip: the chip to unregister
1477 * A gpio_chip with any GPIOs still requested may not be removed.
1479 void gpiochip_remove(struct gpio_chip *chip)
1481 struct gpio_device *gdev = chip->gpiodev;
1482 struct gpio_desc *desc;
1483 unsigned long flags;
1485 bool requested = false;
1487 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1488 gpiochip_sysfs_unregister(gdev);
1489 gpiochip_free_hogs(chip);
1490 /* Numb the device, cancelling all outstanding operations */
1492 gpiochip_irqchip_remove(chip);
1493 acpi_gpiochip_remove(chip);
1494 gpiochip_remove_pin_ranges(chip);
1495 of_gpiochip_remove(chip);
1496 gpiochip_free_valid_mask(chip);
1498 * We accept no more calls into the driver from this point, so
1499 * NULL the driver data pointer
1503 spin_lock_irqsave(&gpio_lock, flags);
1504 for (i = 0; i < gdev->ngpio; i++) {
1505 desc = &gdev->descs[i];
1506 if (test_bit(FLAG_REQUESTED, &desc->flags))
1509 spin_unlock_irqrestore(&gpio_lock, flags);
1512 dev_crit(&gdev->dev,
1513 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1516 * The gpiochip side puts its use of the device to rest here:
1517 * if there are no userspace clients, the chardev and device will
1518 * be removed, else it will be dangling until the last user is
1521 cdev_device_del(&gdev->chrdev, &gdev->dev);
1522 put_device(&gdev->dev);
1524 EXPORT_SYMBOL_GPL(gpiochip_remove);
1526 static void devm_gpio_chip_release(struct device *dev, void *res)
1528 struct gpio_chip *chip = *(struct gpio_chip **)res;
1530 gpiochip_remove(chip);
1534 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1535 * @dev: pointer to the device that gpio_chip belongs to.
1536 * @chip: the chip to register, with chip->base initialized
1537 * @data: driver-private data associated with this chip
1539 * Context: potentially before irqs will work
1541 * The gpio chip automatically be released when the device is unbound.
1544 * A negative errno if the chip can't be registered, such as because the
1545 * chip->base is invalid or already associated with a different chip.
1546 * Otherwise it returns zero as a success code.
1548 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1551 struct gpio_chip **ptr;
1554 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1559 ret = gpiochip_add_data(chip, data);
1566 devres_add(dev, ptr);
1570 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1573 * gpiochip_find() - iterator for locating a specific gpio_chip
1574 * @data: data to pass to match function
1575 * @match: Callback function to check gpio_chip
1577 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1578 * determined by a user supplied @match callback. The callback should return
1579 * 0 if the device doesn't match and non-zero if it does. If the callback is
1580 * non-zero, this function will return to the caller and not iterate over any
1583 struct gpio_chip *gpiochip_find(void *data,
1584 int (*match)(struct gpio_chip *chip,
1587 struct gpio_device *gdev;
1588 struct gpio_chip *chip = NULL;
1589 unsigned long flags;
1591 spin_lock_irqsave(&gpio_lock, flags);
1592 list_for_each_entry(gdev, &gpio_devices, list)
1593 if (gdev->chip && match(gdev->chip, data)) {
1598 spin_unlock_irqrestore(&gpio_lock, flags);
1602 EXPORT_SYMBOL_GPL(gpiochip_find);
1604 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1606 const char *name = data;
1608 return !strcmp(chip->label, name);
1611 static struct gpio_chip *find_chip_by_name(const char *name)
1613 return gpiochip_find((void *)name, gpiochip_match_name);
1616 #ifdef CONFIG_GPIOLIB_IRQCHIP
1619 * The following is irqchip helper code for gpiochips.
1622 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1624 if (!gpiochip->irq.need_valid_mask)
1627 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1628 if (!gpiochip->irq.valid_mask)
1634 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1636 kfree(gpiochip->irq.valid_mask);
1637 gpiochip->irq.valid_mask = NULL;
1640 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1641 unsigned int offset)
1643 if (!gpiochip_line_is_valid(gpiochip, offset))
1645 /* No mask means all valid */
1646 if (likely(!gpiochip->irq.valid_mask))
1648 return test_bit(offset, gpiochip->irq.valid_mask);
1650 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1653 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1654 * @gc: the gpiochip to set the irqchip chain to
1655 * @parent_irq: the irq number corresponding to the parent IRQ for this
1657 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1658 * coming out of the gpiochip. If the interrupt is nested rather than
1659 * cascaded, pass NULL in this handler argument
1661 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gc,
1662 unsigned int parent_irq,
1663 irq_flow_handler_t parent_handler)
1665 struct gpio_irq_chip *girq = &gc->irq;
1666 struct device *dev = &gc->gpiodev->dev;
1668 if (!girq->domain) {
1669 chip_err(gc, "called %s before setting up irqchip\n",
1674 if (parent_handler) {
1675 if (gc->can_sleep) {
1677 "you cannot have chained interrupts on a chip that may sleep\n");
1680 girq->parents = devm_kcalloc(dev, 1,
1681 sizeof(*girq->parents),
1683 if (!girq->parents) {
1684 chip_err(gc, "out of memory allocating parent IRQ\n");
1687 girq->parents[0] = parent_irq;
1688 girq->num_parents = 1;
1690 * The parent irqchip is already using the chip_data for this
1691 * irqchip, so our callbacks simply use the handler_data.
1693 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1699 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1700 * @gpiochip: the gpiochip to set the irqchip chain to
1701 * @irqchip: the irqchip to chain to the gpiochip
1702 * @parent_irq: the irq number corresponding to the parent IRQ for this
1704 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1705 * coming out of the gpiochip.
1707 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1708 struct irq_chip *irqchip,
1709 unsigned int parent_irq,
1710 irq_flow_handler_t parent_handler)
1712 if (gpiochip->irq.threaded) {
1713 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1717 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1719 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1722 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1723 * @gpiochip: the gpiochip to set the irqchip nested handler to
1724 * @irqchip: the irqchip to nest to the gpiochip
1725 * @parent_irq: the irq number corresponding to the parent IRQ for this
1728 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1729 struct irq_chip *irqchip,
1730 unsigned int parent_irq)
1732 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1734 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1737 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1738 * @d: the irqdomain used by this irqchip
1739 * @irq: the global irq number used by this GPIO irqchip irq
1740 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1742 * This function will set up the mapping for a certain IRQ line on a
1743 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1744 * stored inside the gpiochip.
1746 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1747 irq_hw_number_t hwirq)
1749 struct gpio_chip *chip = d->host_data;
1752 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1755 irq_set_chip_data(irq, chip);
1757 * This lock class tells lockdep that GPIO irqs are in a different
1758 * category than their parents, so it won't report false recursion.
1760 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1761 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1762 /* Chips that use nested thread handlers have them marked */
1763 if (chip->irq.threaded)
1764 irq_set_nested_thread(irq, 1);
1765 irq_set_noprobe(irq);
1767 if (chip->irq.num_parents == 1)
1768 err = irq_set_parent(irq, chip->irq.parents[0]);
1769 else if (chip->irq.map)
1770 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1776 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1777 * is passed as default type.
1779 if (chip->irq.default_type != IRQ_TYPE_NONE)
1780 irq_set_irq_type(irq, chip->irq.default_type);
1784 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1786 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1788 struct gpio_chip *chip = d->host_data;
1790 if (chip->irq.threaded)
1791 irq_set_nested_thread(irq, 0);
1792 irq_set_chip_and_handler(irq, NULL, NULL);
1793 irq_set_chip_data(irq, NULL);
1795 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1797 static const struct irq_domain_ops gpiochip_domain_ops = {
1798 .map = gpiochip_irq_map,
1799 .unmap = gpiochip_irq_unmap,
1800 /* Virtually all GPIO irqchips are twocell:ed */
1801 .xlate = irq_domain_xlate_twocell,
1805 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1806 * @domain: The IRQ domain used by this IRQ chip
1807 * @data: Outermost irq_data associated with the IRQ
1808 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1810 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1811 * used as the activate function for the &struct irq_domain_ops. The host_data
1812 * for the IRQ domain must be the &struct gpio_chip.
1814 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1815 struct irq_data *data, bool reserve)
1817 struct gpio_chip *chip = domain->host_data;
1819 return gpiochip_lock_as_irq(chip, data->hwirq);
1821 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1824 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1825 * @domain: The IRQ domain used by this IRQ chip
1826 * @data: Outermost irq_data associated with the IRQ
1828 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1829 * be used as the deactivate function for the &struct irq_domain_ops. The
1830 * host_data for the IRQ domain must be the &struct gpio_chip.
1832 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1833 struct irq_data *data)
1835 struct gpio_chip *chip = domain->host_data;
1837 return gpiochip_unlock_as_irq(chip, data->hwirq);
1839 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1841 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1843 if (!gpiochip_irqchip_irq_valid(chip, offset))
1846 return irq_create_mapping(chip->irq.domain, offset);
1849 static int gpiochip_irq_reqres(struct irq_data *d)
1851 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1853 return gpiochip_reqres_irq(chip, d->hwirq);
1856 static void gpiochip_irq_relres(struct irq_data *d)
1858 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1860 gpiochip_relres_irq(chip, d->hwirq);
1863 static void gpiochip_irq_enable(struct irq_data *d)
1865 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1867 gpiochip_enable_irq(chip, d->hwirq);
1868 if (chip->irq.irq_enable)
1869 chip->irq.irq_enable(d);
1871 chip->irq.chip->irq_unmask(d);
1874 static void gpiochip_irq_disable(struct irq_data *d)
1876 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1878 if (chip->irq.irq_disable)
1879 chip->irq.irq_disable(d);
1881 chip->irq.chip->irq_mask(d);
1882 gpiochip_disable_irq(chip, d->hwirq);
1885 static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
1887 struct irq_chip *irqchip = gpiochip->irq.chip;
1889 if (!irqchip->irq_request_resources &&
1890 !irqchip->irq_release_resources) {
1891 irqchip->irq_request_resources = gpiochip_irq_reqres;
1892 irqchip->irq_release_resources = gpiochip_irq_relres;
1894 if (WARN_ON(gpiochip->irq.irq_enable))
1896 /* Check if the irqchip already has this hook... */
1897 if (irqchip->irq_enable == gpiochip_irq_enable) {
1899 * ...and if so, give a gentle warning that this is bad
1903 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1906 gpiochip->irq.irq_enable = irqchip->irq_enable;
1907 gpiochip->irq.irq_disable = irqchip->irq_disable;
1908 irqchip->irq_enable = gpiochip_irq_enable;
1909 irqchip->irq_disable = gpiochip_irq_disable;
1913 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1914 * @gpiochip: the GPIO chip to add the IRQ chip to
1915 * @lock_key: lockdep class for IRQ lock
1916 * @request_key: lockdep class for IRQ request
1918 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1919 struct lock_class_key *lock_key,
1920 struct lock_class_key *request_key)
1922 struct irq_chip *irqchip = gpiochip->irq.chip;
1923 const struct irq_domain_ops *ops;
1924 struct device_node *np;
1931 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1932 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1936 np = gpiochip->gpiodev->dev.of_node;
1937 type = gpiochip->irq.default_type;
1940 * Specifying a default trigger is a terrible idea if DT or ACPI is
1941 * used to configure the interrupts, as you may end up with
1942 * conflicting triggers. Tell the user, and reset to NONE.
1944 if (WARN(np && type != IRQ_TYPE_NONE,
1945 "%s: Ignoring %u default trigger\n", np->full_name, type))
1946 type = IRQ_TYPE_NONE;
1948 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1949 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1950 "Ignoring %u default trigger\n", type);
1951 type = IRQ_TYPE_NONE;
1954 gpiochip->to_irq = gpiochip_to_irq;
1955 gpiochip->irq.default_type = type;
1956 gpiochip->irq.lock_key = lock_key;
1957 gpiochip->irq.request_key = request_key;
1959 if (gpiochip->irq.domain_ops)
1960 ops = gpiochip->irq.domain_ops;
1962 ops = &gpiochip_domain_ops;
1964 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1965 gpiochip->irq.first,
1967 if (!gpiochip->irq.domain)
1970 if (gpiochip->irq.parent_handler) {
1971 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1973 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1975 * The parent IRQ chip is already using the chip_data
1976 * for this IRQ chip, so our callbacks simply use the
1979 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1980 gpiochip->irq.parent_handler,
1985 gpiochip_set_irq_hooks(gpiochip);
1987 acpi_gpiochip_request_interrupts(gpiochip);
1993 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1994 * @gpiochip: the gpiochip to remove the irqchip from
1996 * This is called only from gpiochip_remove()
1998 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
2000 struct irq_chip *irqchip = gpiochip->irq.chip;
2001 unsigned int offset;
2003 acpi_gpiochip_free_interrupts(gpiochip);
2005 if (irqchip && gpiochip->irq.parent_handler) {
2006 struct gpio_irq_chip *irq = &gpiochip->irq;
2009 for (i = 0; i < irq->num_parents; i++)
2010 irq_set_chained_handler_and_data(irq->parents[i],
2014 /* Remove all IRQ mappings and delete the domain */
2015 if (gpiochip->irq.domain) {
2018 for (offset = 0; offset < gpiochip->ngpio; offset++) {
2019 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
2022 irq = irq_find_mapping(gpiochip->irq.domain, offset);
2023 irq_dispose_mapping(irq);
2026 irq_domain_remove(gpiochip->irq.domain);
2030 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2031 irqchip->irq_request_resources = NULL;
2032 irqchip->irq_release_resources = NULL;
2034 if (irqchip->irq_enable == gpiochip_irq_enable) {
2035 irqchip->irq_enable = gpiochip->irq.irq_enable;
2036 irqchip->irq_disable = gpiochip->irq.irq_disable;
2039 gpiochip->irq.irq_enable = NULL;
2040 gpiochip->irq.irq_disable = NULL;
2041 gpiochip->irq.chip = NULL;
2043 gpiochip_irqchip_free_valid_mask(gpiochip);
2047 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2048 * @gpiochip: the gpiochip to add the irqchip to
2049 * @irqchip: the irqchip to add to the gpiochip
2050 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2051 * allocate gpiochip irqs from
2052 * @handler: the irq handler to use (often a predefined irq core function)
2053 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2054 * to have the core avoid setting up any default type in the hardware.
2055 * @threaded: whether this irqchip uses a nested thread handler
2056 * @lock_key: lockdep class for IRQ lock
2057 * @request_key: lockdep class for IRQ request
2059 * This function closely associates a certain irqchip with a certain
2060 * gpiochip, providing an irq domain to translate the local IRQs to
2061 * global irqs in the gpiolib core, and making sure that the gpiochip
2062 * is passed as chip data to all related functions. Driver callbacks
2063 * need to use gpiochip_get_data() to get their local state containers back
2064 * from the gpiochip passed as chip data. An irqdomain will be stored
2065 * in the gpiochip that shall be used by the driver to handle IRQ number
2066 * translation. The gpiochip will need to be initialized and registered
2067 * before calling this function.
2069 * This function will handle two cell:ed simple IRQs and assumes all
2070 * the pins on the gpiochip can generate a unique IRQ. Everything else
2071 * need to be open coded.
2073 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2074 struct irq_chip *irqchip,
2075 unsigned int first_irq,
2076 irq_flow_handler_t handler,
2079 struct lock_class_key *lock_key,
2080 struct lock_class_key *request_key)
2082 struct device_node *of_node;
2084 if (!gpiochip || !irqchip)
2087 if (!gpiochip->parent) {
2088 pr_err("missing gpiochip .dev parent pointer\n");
2091 gpiochip->irq.threaded = threaded;
2092 of_node = gpiochip->parent->of_node;
2093 #ifdef CONFIG_OF_GPIO
2095 * If the gpiochip has an assigned OF node this takes precedence
2096 * FIXME: get rid of this and use gpiochip->parent->of_node
2099 if (gpiochip->of_node)
2100 of_node = gpiochip->of_node;
2103 * Specifying a default trigger is a terrible idea if DT or ACPI is
2104 * used to configure the interrupts, as you may end-up with
2105 * conflicting triggers. Tell the user, and reset to NONE.
2107 if (WARN(of_node && type != IRQ_TYPE_NONE,
2108 "%pOF: Ignoring %d default trigger\n", of_node, type))
2109 type = IRQ_TYPE_NONE;
2110 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2111 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2112 "Ignoring %d default trigger\n", type);
2113 type = IRQ_TYPE_NONE;
2116 gpiochip->irq.chip = irqchip;
2117 gpiochip->irq.handler = handler;
2118 gpiochip->irq.default_type = type;
2119 gpiochip->to_irq = gpiochip_to_irq;
2120 gpiochip->irq.lock_key = lock_key;
2121 gpiochip->irq.request_key = request_key;
2122 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2123 gpiochip->ngpio, first_irq,
2124 &gpiochip_domain_ops, gpiochip);
2125 if (!gpiochip->irq.domain) {
2126 gpiochip->irq.chip = NULL;
2130 gpiochip_set_irq_hooks(gpiochip);
2132 acpi_gpiochip_request_interrupts(gpiochip);
2136 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2138 #else /* CONFIG_GPIOLIB_IRQCHIP */
2140 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2141 struct lock_class_key *lock_key,
2142 struct lock_class_key *request_key)
2147 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2148 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2152 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2155 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2158 * gpiochip_generic_request() - request the gpio function for a pin
2159 * @chip: the gpiochip owning the GPIO
2160 * @offset: the offset of the GPIO to request for GPIO function
2162 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2164 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2166 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2169 * gpiochip_generic_free() - free the gpio function from a pin
2170 * @chip: the gpiochip to request the gpio function for
2171 * @offset: the offset of the GPIO to free from GPIO function
2173 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2175 pinctrl_gpio_free(chip->gpiodev->base + offset);
2177 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2180 * gpiochip_generic_config() - apply configuration for a pin
2181 * @chip: the gpiochip owning the GPIO
2182 * @offset: the offset of the GPIO to apply the configuration
2183 * @config: the configuration to be applied
2185 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2186 unsigned long config)
2188 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2190 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2192 #ifdef CONFIG_PINCTRL
2195 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2196 * @chip: the gpiochip to add the range for
2197 * @pctldev: the pin controller to map to
2198 * @gpio_offset: the start offset in the current gpio_chip number space
2199 * @pin_group: name of the pin group inside the pin controller
2201 * Calling this function directly from a DeviceTree-supported
2202 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2203 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2204 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2206 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2207 struct pinctrl_dev *pctldev,
2208 unsigned int gpio_offset, const char *pin_group)
2210 struct gpio_pin_range *pin_range;
2211 struct gpio_device *gdev = chip->gpiodev;
2214 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2216 chip_err(chip, "failed to allocate pin ranges\n");
2220 /* Use local offset as range ID */
2221 pin_range->range.id = gpio_offset;
2222 pin_range->range.gc = chip;
2223 pin_range->range.name = chip->label;
2224 pin_range->range.base = gdev->base + gpio_offset;
2225 pin_range->pctldev = pctldev;
2227 ret = pinctrl_get_group_pins(pctldev, pin_group,
2228 &pin_range->range.pins,
2229 &pin_range->range.npins);
2235 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2237 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2238 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2239 pinctrl_dev_get_devname(pctldev), pin_group);
2241 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2245 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2248 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2249 * @chip: the gpiochip to add the range for
2250 * @pinctl_name: the dev_name() of the pin controller to map to
2251 * @gpio_offset: the start offset in the current gpio_chip number space
2252 * @pin_offset: the start offset in the pin controller number space
2253 * @npins: the number of pins from the offset of each pin space (GPIO and
2254 * pin controller) to accumulate in this range
2257 * 0 on success, or a negative error-code on failure.
2259 * Calling this function directly from a DeviceTree-supported
2260 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2261 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2262 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2264 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2265 unsigned int gpio_offset, unsigned int pin_offset,
2268 struct gpio_pin_range *pin_range;
2269 struct gpio_device *gdev = chip->gpiodev;
2272 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2274 chip_err(chip, "failed to allocate pin ranges\n");
2278 /* Use local offset as range ID */
2279 pin_range->range.id = gpio_offset;
2280 pin_range->range.gc = chip;
2281 pin_range->range.name = chip->label;
2282 pin_range->range.base = gdev->base + gpio_offset;
2283 pin_range->range.pin_base = pin_offset;
2284 pin_range->range.npins = npins;
2285 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2287 if (IS_ERR(pin_range->pctldev)) {
2288 ret = PTR_ERR(pin_range->pctldev);
2289 chip_err(chip, "could not create pin range\n");
2293 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2294 gpio_offset, gpio_offset + npins - 1,
2296 pin_offset, pin_offset + npins - 1);
2298 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2302 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2305 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2306 * @chip: the chip to remove all the mappings for
2308 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2310 struct gpio_pin_range *pin_range, *tmp;
2311 struct gpio_device *gdev = chip->gpiodev;
2313 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2314 list_del(&pin_range->node);
2315 pinctrl_remove_gpio_range(pin_range->pctldev,
2320 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2322 #endif /* CONFIG_PINCTRL */
2324 /* These "optional" allocation calls help prevent drivers from stomping
2325 * on each other, and help provide better diagnostics in debugfs.
2326 * They're called even less than the "set direction" calls.
2328 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2330 struct gpio_chip *chip = desc->gdev->chip;
2332 unsigned long flags;
2336 label = kstrdup_const(label, GFP_KERNEL);
2341 spin_lock_irqsave(&gpio_lock, flags);
2343 /* NOTE: gpio_request() can be called in early boot,
2344 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2347 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2348 desc_set_label(desc, label ? : "?");
2356 if (chip->request) {
2357 /* chip->request may sleep */
2358 spin_unlock_irqrestore(&gpio_lock, flags);
2359 offset = gpio_chip_hwgpio(desc);
2360 if (gpiochip_line_is_valid(chip, offset))
2361 status = chip->request(chip, offset);
2364 spin_lock_irqsave(&gpio_lock, flags);
2367 desc_set_label(desc, NULL);
2369 clear_bit(FLAG_REQUESTED, &desc->flags);
2373 if (chip->get_direction) {
2374 /* chip->get_direction may sleep */
2375 spin_unlock_irqrestore(&gpio_lock, flags);
2376 gpiod_get_direction(desc);
2377 spin_lock_irqsave(&gpio_lock, flags);
2380 spin_unlock_irqrestore(&gpio_lock, flags);
2385 * This descriptor validation needs to be inserted verbatim into each
2386 * function taking a descriptor, so we need to use a preprocessor
2387 * macro to avoid endless duplication. If the desc is NULL it is an
2388 * optional GPIO and calls should just bail out.
2390 static int validate_desc(const struct gpio_desc *desc, const char *func)
2395 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2396 return PTR_ERR(desc);
2399 pr_warn("%s: invalid GPIO (no device)\n", func);
2402 if (!desc->gdev->chip) {
2403 dev_warn(&desc->gdev->dev,
2404 "%s: backing chip is gone\n", func);
2410 #define VALIDATE_DESC(desc) do { \
2411 int __valid = validate_desc(desc, __func__); \
2416 #define VALIDATE_DESC_VOID(desc) do { \
2417 int __valid = validate_desc(desc, __func__); \
2422 int gpiod_request(struct gpio_desc *desc, const char *label)
2424 int status = -EPROBE_DEFER;
2425 struct gpio_device *gdev;
2427 VALIDATE_DESC(desc);
2430 if (try_module_get(gdev->owner)) {
2431 status = gpiod_request_commit(desc, label);
2433 module_put(gdev->owner);
2435 get_device(&gdev->dev);
2439 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2444 static bool gpiod_free_commit(struct gpio_desc *desc)
2447 unsigned long flags;
2448 struct gpio_chip *chip;
2452 gpiod_unexport(desc);
2454 spin_lock_irqsave(&gpio_lock, flags);
2456 chip = desc->gdev->chip;
2457 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2459 spin_unlock_irqrestore(&gpio_lock, flags);
2460 might_sleep_if(chip->can_sleep);
2461 chip->free(chip, gpio_chip_hwgpio(desc));
2462 spin_lock_irqsave(&gpio_lock, flags);
2464 kfree_const(desc->label);
2465 desc_set_label(desc, NULL);
2466 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2467 clear_bit(FLAG_REQUESTED, &desc->flags);
2468 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2469 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2470 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2474 spin_unlock_irqrestore(&gpio_lock, flags);
2478 void gpiod_free(struct gpio_desc *desc)
2480 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2481 module_put(desc->gdev->owner);
2482 put_device(&desc->gdev->dev);
2484 WARN_ON(extra_checks);
2489 * gpiochip_is_requested - return string iff signal was requested
2490 * @chip: controller managing the signal
2491 * @offset: of signal within controller's 0..(ngpio - 1) range
2493 * Returns NULL if the GPIO is not currently requested, else a string.
2494 * The string returned is the label passed to gpio_request(); if none has been
2495 * passed it is a meaningless, non-NULL constant.
2497 * This function is for use by GPIO controller drivers. The label can
2498 * help with diagnostics, and knowing that the signal is used as a GPIO
2499 * can help avoid accidentally multiplexing it to another controller.
2501 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2503 struct gpio_desc *desc;
2505 if (offset >= chip->ngpio)
2508 desc = &chip->gpiodev->descs[offset];
2510 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2514 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2517 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2519 * @hwnum: hardware number of the GPIO for which to request the descriptor
2520 * @label: label for the GPIO
2521 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2522 * specify things like line inversion semantics with the machine flags
2523 * such as GPIO_OUT_LOW
2524 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2525 * can be used to specify consumer semantics such as open drain
2527 * Function allows GPIO chip drivers to request and use their own GPIO
2528 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2529 * function will not increase reference count of the GPIO chip module. This
2530 * allows the GPIO chip module to be unloaded as needed (we assume that the
2531 * GPIO chip driver handles freeing the GPIOs it has requested).
2534 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2537 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2539 enum gpio_lookup_flags lflags,
2540 enum gpiod_flags dflags)
2542 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2546 chip_err(chip, "failed to get GPIO descriptor\n");
2550 err = gpiod_request_commit(desc, label);
2552 return ERR_PTR(err);
2554 err = gpiod_configure_flags(desc, label, lflags, dflags);
2556 chip_err(chip, "setup of own GPIO %s failed\n", label);
2557 gpiod_free_commit(desc);
2558 return ERR_PTR(err);
2563 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2566 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2567 * @desc: GPIO descriptor to free
2569 * Function frees the given GPIO requested previously with
2570 * gpiochip_request_own_desc().
2572 void gpiochip_free_own_desc(struct gpio_desc *desc)
2575 gpiod_free_commit(desc);
2577 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2580 * Drivers MUST set GPIO direction before making get/set calls. In
2581 * some cases this is done in early boot, before IRQs are enabled.
2583 * As a rule these aren't called more than once (except for drivers
2584 * using the open-drain emulation idiom) so these are natural places
2585 * to accumulate extra debugging checks. Note that we can't (yet)
2586 * rely on gpio_request() having been called beforehand.
2589 static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
2590 enum pin_config_param mode)
2592 unsigned long config;
2596 case PIN_CONFIG_BIAS_PULL_DOWN:
2597 case PIN_CONFIG_BIAS_PULL_UP:
2605 config = PIN_CONF_PACKED(mode, arg);
2606 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2610 * gpiod_direction_input - set the GPIO direction to input
2611 * @desc: GPIO to set to input
2613 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2614 * be called safely on it.
2616 * Return 0 in case of success, else an error code.
2618 int gpiod_direction_input(struct gpio_desc *desc)
2620 struct gpio_chip *chip;
2623 VALIDATE_DESC(desc);
2624 chip = desc->gdev->chip;
2627 * It is legal to have no .get() and .direction_input() specified if
2628 * the chip is output-only, but you can't specify .direction_input()
2629 * and not support the .get() operation, that doesn't make sense.
2631 if (!chip->get && chip->direction_input) {
2633 "%s: missing get() but have direction_input()\n",
2639 * If we have a .direction_input() callback, things are simple,
2640 * just call it. Else we are some input-only chip so try to check the
2641 * direction (if .get_direction() is supported) else we silently
2642 * assume we are in input mode after this.
2644 if (chip->direction_input) {
2645 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2646 } else if (chip->get_direction &&
2647 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2649 "%s: missing direction_input() operation and line is output\n",
2654 clear_bit(FLAG_IS_OUT, &desc->flags);
2656 if (test_bit(FLAG_PULL_UP, &desc->flags))
2657 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2658 PIN_CONFIG_BIAS_PULL_UP);
2659 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2660 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2661 PIN_CONFIG_BIAS_PULL_DOWN);
2663 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2667 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2669 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2671 struct gpio_chip *gc = desc->gdev->chip;
2676 * It's OK not to specify .direction_output() if the gpiochip is
2677 * output-only, but if there is then not even a .set() operation it
2678 * is pretty tricky to drive the output line.
2680 if (!gc->set && !gc->direction_output) {
2682 "%s: missing set() and direction_output() operations\n",
2687 if (gc->direction_output) {
2688 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2690 /* Check that we are in output mode if we can */
2691 if (gc->get_direction &&
2692 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2694 "%s: missing direction_output() operation\n",
2699 * If we can't actively set the direction, we are some
2700 * output-only chip, so just drive the output as desired.
2702 gc->set(gc, gpio_chip_hwgpio(desc), val);
2706 set_bit(FLAG_IS_OUT, &desc->flags);
2707 trace_gpio_value(desc_to_gpio(desc), 0, val);
2708 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2713 * gpiod_direction_output_raw - set the GPIO direction to output
2714 * @desc: GPIO to set to output
2715 * @value: initial output value of the GPIO
2717 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2718 * be called safely on it. The initial value of the output must be specified
2719 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2721 * Return 0 in case of success, else an error code.
2723 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2725 VALIDATE_DESC(desc);
2726 return gpiod_direction_output_raw_commit(desc, value);
2728 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2731 * gpiod_direction_output - set the GPIO direction to output
2732 * @desc: GPIO to set to output
2733 * @value: initial output value of the GPIO
2735 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2736 * be called safely on it. The initial value of the output must be specified
2737 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2740 * Return 0 in case of success, else an error code.
2742 int gpiod_direction_output(struct gpio_desc *desc, int value)
2744 struct gpio_chip *gc;
2747 VALIDATE_DESC(desc);
2748 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2753 /* GPIOs used for enabled IRQs shall not be set as output */
2754 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2755 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2757 "%s: tried to set a GPIO tied to an IRQ as output\n",
2762 gc = desc->gdev->chip;
2763 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2764 /* First see if we can enable open drain in hardware */
2765 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2766 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2768 goto set_output_value;
2769 /* Emulate open drain by not actively driving the line high */
2771 return gpiod_direction_input(desc);
2773 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2774 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2775 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2777 goto set_output_value;
2778 /* Emulate open source by not actively driving the line low */
2780 return gpiod_direction_input(desc);
2782 gpio_set_config(gc, gpio_chip_hwgpio(desc),
2783 PIN_CONFIG_DRIVE_PUSH_PULL);
2787 return gpiod_direction_output_raw_commit(desc, value);
2789 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2792 * gpiod_set_debounce - sets @debounce time for a GPIO
2793 * @desc: descriptor of the GPIO for which to set debounce time
2794 * @debounce: debounce time in microseconds
2797 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2800 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2802 struct gpio_chip *chip;
2803 unsigned long config;
2805 VALIDATE_DESC(desc);
2806 chip = desc->gdev->chip;
2807 if (!chip->set || !chip->set_config) {
2809 "%s: missing set() or set_config() operations\n",
2814 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2815 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2817 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2820 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2821 * @desc: descriptor of the GPIO for which to configure persistence
2822 * @transitory: True to lose state on suspend or reset, false for persistence
2825 * 0 on success, otherwise a negative error code.
2827 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2829 struct gpio_chip *chip;
2830 unsigned long packed;
2834 VALIDATE_DESC(desc);
2836 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2837 * persistence state.
2840 set_bit(FLAG_TRANSITORY, &desc->flags);
2842 clear_bit(FLAG_TRANSITORY, &desc->flags);
2844 /* If the driver supports it, set the persistence state now */
2845 chip = desc->gdev->chip;
2846 if (!chip->set_config)
2849 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2851 gpio = gpio_chip_hwgpio(desc);
2852 rc = chip->set_config(chip, gpio, packed);
2853 if (rc == -ENOTSUPP) {
2854 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2861 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2864 * gpiod_is_active_low - test whether a GPIO is active-low or not
2865 * @desc: the gpio descriptor to test
2867 * Returns 1 if the GPIO is active-low, 0 otherwise.
2869 int gpiod_is_active_low(const struct gpio_desc *desc)
2871 VALIDATE_DESC(desc);
2872 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2874 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2876 /* I/O calls are only valid after configuration completed; the relevant
2877 * "is this a valid GPIO" error checks should already have been done.
2879 * "Get" operations are often inlinable as reading a pin value register,
2880 * and masking the relevant bit in that register.
2882 * When "set" operations are inlinable, they involve writing that mask to
2883 * one register to set a low value, or a different register to set it high.
2884 * Otherwise locking is needed, so there may be little value to inlining.
2886 *------------------------------------------------------------------------
2888 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2889 * have requested the GPIO. That can include implicit requesting by
2890 * a direction setting call. Marking a gpio as requested locks its chip
2891 * in memory, guaranteeing that these table lookups need no more locking
2892 * and that gpiochip_remove() will fail.
2894 * REVISIT when debugging, consider adding some instrumentation to ensure
2895 * that the GPIO was actually requested.
2898 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2900 struct gpio_chip *chip;
2904 chip = desc->gdev->chip;
2905 offset = gpio_chip_hwgpio(desc);
2906 value = chip->get ? chip->get(chip, offset) : -EIO;
2907 value = value < 0 ? value : !!value;
2908 trace_gpio_value(desc_to_gpio(desc), 1, value);
2912 static int gpio_chip_get_multiple(struct gpio_chip *chip,
2913 unsigned long *mask, unsigned long *bits)
2915 if (chip->get_multiple) {
2916 return chip->get_multiple(chip, mask, bits);
2917 } else if (chip->get) {
2920 for_each_set_bit(i, mask, chip->ngpio) {
2921 value = chip->get(chip, i);
2924 __assign_bit(i, bits, value);
2931 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2932 unsigned int array_size,
2933 struct gpio_desc **desc_array,
2934 struct gpio_array *array_info,
2935 unsigned long *value_bitmap)
2940 * Validate array_info against desc_array and its size.
2941 * It should immediately follow desc_array if both
2942 * have been obtained from the same gpiod_get_array() call.
2944 if (array_info && array_info->desc == desc_array &&
2945 array_size <= array_info->size &&
2946 (void *)array_info == desc_array + array_info->size) {
2948 WARN_ON(array_info->chip->can_sleep);
2950 err = gpio_chip_get_multiple(array_info->chip,
2951 array_info->get_mask,
2956 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2957 bitmap_xor(value_bitmap, value_bitmap,
2958 array_info->invert_mask, array_size);
2960 if (bitmap_full(array_info->get_mask, array_size))
2963 i = find_first_zero_bit(array_info->get_mask, array_size);
2968 while (i < array_size) {
2969 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2970 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2971 unsigned long *mask, *bits;
2974 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2977 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2979 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2984 bits = mask + BITS_TO_LONGS(chip->ngpio);
2985 bitmap_zero(mask, chip->ngpio);
2988 WARN_ON(chip->can_sleep);
2990 /* collect all inputs belonging to the same chip */
2993 const struct gpio_desc *desc = desc_array[i];
2994 int hwgpio = gpio_chip_hwgpio(desc);
2996 __set_bit(hwgpio, mask);
3000 i = find_next_zero_bit(array_info->get_mask,
3002 } while ((i < array_size) &&
3003 (desc_array[i]->gdev->chip == chip));
3005 ret = gpio_chip_get_multiple(chip, mask, bits);
3007 if (mask != fastpath)
3012 for (j = first; j < i; ) {
3013 const struct gpio_desc *desc = desc_array[j];
3014 int hwgpio = gpio_chip_hwgpio(desc);
3015 int value = test_bit(hwgpio, bits);
3017 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3019 __assign_bit(j, value_bitmap, value);
3020 trace_gpio_value(desc_to_gpio(desc), 1, value);
3024 j = find_next_zero_bit(array_info->get_mask, i,
3028 if (mask != fastpath)
3035 * gpiod_get_raw_value() - return a gpio's raw value
3036 * @desc: gpio whose value will be returned
3038 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3039 * its ACTIVE_LOW status, or negative errno on failure.
3041 * This function can be called from contexts where we cannot sleep, and will
3042 * complain if the GPIO chip functions potentially sleep.
3044 int gpiod_get_raw_value(const struct gpio_desc *desc)
3046 VALIDATE_DESC(desc);
3047 /* Should be using gpiod_get_raw_value_cansleep() */
3048 WARN_ON(desc->gdev->chip->can_sleep);
3049 return gpiod_get_raw_value_commit(desc);
3051 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3054 * gpiod_get_value() - return a gpio's value
3055 * @desc: gpio whose value will be returned
3057 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3058 * account, or negative errno on failure.
3060 * This function can be called from contexts where we cannot sleep, and will
3061 * complain if the GPIO chip functions potentially sleep.
3063 int gpiod_get_value(const struct gpio_desc *desc)
3067 VALIDATE_DESC(desc);
3068 /* Should be using gpiod_get_value_cansleep() */
3069 WARN_ON(desc->gdev->chip->can_sleep);
3071 value = gpiod_get_raw_value_commit(desc);
3075 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3080 EXPORT_SYMBOL_GPL(gpiod_get_value);
3083 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3084 * @array_size: number of elements in the descriptor array / value bitmap
3085 * @desc_array: array of GPIO descriptors whose values will be read
3086 * @array_info: information on applicability of fast bitmap processing path
3087 * @value_bitmap: bitmap to store the read values
3089 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3090 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3091 * else an error code.
3093 * This function can be called from contexts where we cannot sleep,
3094 * and it will complain if the GPIO chip functions potentially sleep.
3096 int gpiod_get_raw_array_value(unsigned int array_size,
3097 struct gpio_desc **desc_array,
3098 struct gpio_array *array_info,
3099 unsigned long *value_bitmap)
3103 return gpiod_get_array_value_complex(true, false, array_size,
3104 desc_array, array_info,
3107 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3110 * gpiod_get_array_value() - read values from an array of GPIOs
3111 * @array_size: number of elements in the descriptor array / value bitmap
3112 * @desc_array: array of GPIO descriptors whose values will be read
3113 * @array_info: information on applicability of fast bitmap processing path
3114 * @value_bitmap: bitmap to store the read values
3116 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3117 * into account. Return 0 in case of success, else an error code.
3119 * This function can be called from contexts where we cannot sleep,
3120 * and it will complain if the GPIO chip functions potentially sleep.
3122 int gpiod_get_array_value(unsigned int array_size,
3123 struct gpio_desc **desc_array,
3124 struct gpio_array *array_info,
3125 unsigned long *value_bitmap)
3129 return gpiod_get_array_value_complex(false, false, array_size,
3130 desc_array, array_info,
3133 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3136 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3137 * @desc: gpio descriptor whose state need to be set.
3138 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3140 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3143 struct gpio_chip *chip = desc->gdev->chip;
3144 int offset = gpio_chip_hwgpio(desc);
3147 err = chip->direction_input(chip, offset);
3149 clear_bit(FLAG_IS_OUT, &desc->flags);
3151 err = chip->direction_output(chip, offset, 0);
3153 set_bit(FLAG_IS_OUT, &desc->flags);
3155 trace_gpio_direction(desc_to_gpio(desc), value, err);
3158 "%s: Error in set_value for open drain err %d\n",
3163 * _gpio_set_open_source_value() - Set the open source gpio's value.
3164 * @desc: gpio descriptor whose state need to be set.
3165 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3167 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3170 struct gpio_chip *chip = desc->gdev->chip;
3171 int offset = gpio_chip_hwgpio(desc);
3174 err = chip->direction_output(chip, offset, 1);
3176 set_bit(FLAG_IS_OUT, &desc->flags);
3178 err = chip->direction_input(chip, offset);
3180 clear_bit(FLAG_IS_OUT, &desc->flags);
3182 trace_gpio_direction(desc_to_gpio(desc), !value, err);
3185 "%s: Error in set_value for open source err %d\n",
3189 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3191 struct gpio_chip *chip;
3193 chip = desc->gdev->chip;
3194 trace_gpio_value(desc_to_gpio(desc), 0, value);
3195 chip->set(chip, gpio_chip_hwgpio(desc), value);
3199 * set multiple outputs on the same chip;
3200 * use the chip's set_multiple function if available;
3201 * otherwise set the outputs sequentially;
3202 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3203 * defines which outputs are to be changed
3204 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3205 * defines the values the outputs specified by mask are to be set to
3207 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3208 unsigned long *mask, unsigned long *bits)
3210 if (chip->set_multiple) {
3211 chip->set_multiple(chip, mask, bits);
3215 /* set outputs if the corresponding mask bit is set */
3216 for_each_set_bit(i, mask, chip->ngpio)
3217 chip->set(chip, i, test_bit(i, bits));
3221 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3222 unsigned int array_size,
3223 struct gpio_desc **desc_array,
3224 struct gpio_array *array_info,
3225 unsigned long *value_bitmap)
3230 * Validate array_info against desc_array and its size.
3231 * It should immediately follow desc_array if both
3232 * have been obtained from the same gpiod_get_array() call.
3234 if (array_info && array_info->desc == desc_array &&
3235 array_size <= array_info->size &&
3236 (void *)array_info == desc_array + array_info->size) {
3238 WARN_ON(array_info->chip->can_sleep);
3240 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3241 bitmap_xor(value_bitmap, value_bitmap,
3242 array_info->invert_mask, array_size);
3244 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3247 if (bitmap_full(array_info->set_mask, array_size))
3250 i = find_first_zero_bit(array_info->set_mask, array_size);
3255 while (i < array_size) {
3256 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3257 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3258 unsigned long *mask, *bits;
3261 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3264 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3266 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3271 bits = mask + BITS_TO_LONGS(chip->ngpio);
3272 bitmap_zero(mask, chip->ngpio);
3275 WARN_ON(chip->can_sleep);
3278 struct gpio_desc *desc = desc_array[i];
3279 int hwgpio = gpio_chip_hwgpio(desc);
3280 int value = test_bit(i, value_bitmap);
3283 * Pins applicable for fast input but not for
3284 * fast output processing may have been already
3285 * inverted inside the fast path, skip them.
3287 if (!raw && !(array_info &&
3288 test_bit(i, array_info->invert_mask)) &&
3289 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3291 trace_gpio_value(desc_to_gpio(desc), 0, value);
3293 * collect all normal outputs belonging to the same chip
3294 * open drain and open source outputs are set individually
3296 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3297 gpio_set_open_drain_value_commit(desc, value);
3298 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3299 gpio_set_open_source_value_commit(desc, value);
3301 __set_bit(hwgpio, mask);
3303 __set_bit(hwgpio, bits);
3305 __clear_bit(hwgpio, bits);
3311 i = find_next_zero_bit(array_info->set_mask,
3313 } while ((i < array_size) &&
3314 (desc_array[i]->gdev->chip == chip));
3315 /* push collected bits to outputs */
3317 gpio_chip_set_multiple(chip, mask, bits);
3319 if (mask != fastpath)
3326 * gpiod_set_raw_value() - assign a gpio's raw value
3327 * @desc: gpio whose value will be assigned
3328 * @value: value to assign
3330 * Set the raw value of the GPIO, i.e. the value of its physical line without
3331 * regard for its ACTIVE_LOW status.
3333 * This function can be called from contexts where we cannot sleep, and will
3334 * complain if the GPIO chip functions potentially sleep.
3336 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3338 VALIDATE_DESC_VOID(desc);
3339 /* Should be using gpiod_set_raw_value_cansleep() */
3340 WARN_ON(desc->gdev->chip->can_sleep);
3341 gpiod_set_raw_value_commit(desc, value);
3343 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3346 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3347 * @desc: the descriptor to set the value on
3348 * @value: value to set
3350 * This sets the value of a GPIO line backing a descriptor, applying
3351 * different semantic quirks like active low and open drain/source
3354 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3356 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3358 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3359 gpio_set_open_drain_value_commit(desc, value);
3360 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3361 gpio_set_open_source_value_commit(desc, value);
3363 gpiod_set_raw_value_commit(desc, value);
3367 * gpiod_set_value() - assign a gpio's value
3368 * @desc: gpio whose value will be assigned
3369 * @value: value to assign
3371 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3372 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3374 * This function can be called from contexts where we cannot sleep, and will
3375 * complain if the GPIO chip functions potentially sleep.
3377 void gpiod_set_value(struct gpio_desc *desc, int value)
3379 VALIDATE_DESC_VOID(desc);
3380 /* Should be using gpiod_set_value_cansleep() */
3381 WARN_ON(desc->gdev->chip->can_sleep);
3382 gpiod_set_value_nocheck(desc, value);
3384 EXPORT_SYMBOL_GPL(gpiod_set_value);
3387 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3388 * @array_size: number of elements in the descriptor array / value bitmap
3389 * @desc_array: array of GPIO descriptors whose values will be assigned
3390 * @array_info: information on applicability of fast bitmap processing path
3391 * @value_bitmap: bitmap of values to assign
3393 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3394 * without regard for their ACTIVE_LOW status.
3396 * This function can be called from contexts where we cannot sleep, and will
3397 * complain if the GPIO chip functions potentially sleep.
3399 int gpiod_set_raw_array_value(unsigned int array_size,
3400 struct gpio_desc **desc_array,
3401 struct gpio_array *array_info,
3402 unsigned long *value_bitmap)
3406 return gpiod_set_array_value_complex(true, false, array_size,
3407 desc_array, array_info, value_bitmap);
3409 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3412 * gpiod_set_array_value() - assign values to an array of GPIOs
3413 * @array_size: number of elements in the descriptor array / value bitmap
3414 * @desc_array: array of GPIO descriptors whose values will be assigned
3415 * @array_info: information on applicability of fast bitmap processing path
3416 * @value_bitmap: bitmap of values to assign
3418 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3421 * This function can be called from contexts where we cannot sleep, and will
3422 * complain if the GPIO chip functions potentially sleep.
3424 int gpiod_set_array_value(unsigned int array_size,
3425 struct gpio_desc **desc_array,
3426 struct gpio_array *array_info,
3427 unsigned long *value_bitmap)
3431 return gpiod_set_array_value_complex(false, false, array_size,
3432 desc_array, array_info,
3435 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3438 * gpiod_cansleep() - report whether gpio value access may sleep
3439 * @desc: gpio to check
3442 int gpiod_cansleep(const struct gpio_desc *desc)
3444 VALIDATE_DESC(desc);
3445 return desc->gdev->chip->can_sleep;
3447 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3450 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3451 * @desc: gpio to set the consumer name on
3452 * @name: the new consumer name
3454 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3456 VALIDATE_DESC(desc);
3458 name = kstrdup_const(name, GFP_KERNEL);
3463 kfree_const(desc->label);
3464 desc_set_label(desc, name);
3468 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3471 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3472 * @desc: gpio whose IRQ will be returned (already requested)
3474 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3477 int gpiod_to_irq(const struct gpio_desc *desc)
3479 struct gpio_chip *chip;
3483 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3484 * requires this function to not return zero on an invalid descriptor
3485 * but rather a negative error number.
3487 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3490 chip = desc->gdev->chip;
3491 offset = gpio_chip_hwgpio(desc);
3493 int retirq = chip->to_irq(chip, offset);
3495 /* Zero means NO_IRQ */
3503 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3506 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3507 * @chip: the chip the GPIO to lock belongs to
3508 * @offset: the offset of the GPIO to lock as IRQ
3510 * This is used directly by GPIO drivers that want to lock down
3511 * a certain GPIO line to be used for IRQs.
3513 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3515 struct gpio_desc *desc;
3517 desc = gpiochip_get_desc(chip, offset);
3519 return PTR_ERR(desc);
3522 * If it's fast: flush the direction setting if something changed
3525 if (!chip->can_sleep && chip->get_direction) {
3526 int dir = gpiod_get_direction(desc);
3529 chip_err(chip, "%s: cannot get GPIO direction\n",
3535 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3537 "%s: tried to flag a GPIO set as output for IRQ\n",
3542 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3543 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3546 * If the consumer has not set up a label (such as when the
3547 * IRQ is referenced from .to_irq()) we set up a label here
3548 * so it is clear this is used as an interrupt.
3551 desc_set_label(desc, "interrupt");
3555 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3558 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3559 * @chip: the chip the GPIO to lock belongs to
3560 * @offset: the offset of the GPIO to lock as IRQ
3562 * This is used directly by GPIO drivers that want to indicate
3563 * that a certain GPIO is no longer used exclusively for IRQ.
3565 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3567 struct gpio_desc *desc;
3569 desc = gpiochip_get_desc(chip, offset);
3573 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3574 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3576 /* If we only had this marking, erase it */
3577 if (desc->label && !strcmp(desc->label, "interrupt"))
3578 desc_set_label(desc, NULL);
3580 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3582 void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3584 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3586 if (!IS_ERR(desc) &&
3587 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3588 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3590 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3592 void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3594 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3596 if (!IS_ERR(desc) &&
3597 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3598 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags));
3599 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3602 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3604 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3606 if (offset >= chip->ngpio)
3609 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3611 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3613 int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset)
3617 if (!try_module_get(chip->gpiodev->owner))
3620 ret = gpiochip_lock_as_irq(chip, offset);
3622 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset);
3623 module_put(chip->gpiodev->owner);
3628 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3630 void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset)
3632 gpiochip_unlock_as_irq(chip, offset);
3633 module_put(chip->gpiodev->owner);
3635 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3637 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3639 if (offset >= chip->ngpio)
3642 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3644 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3646 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3648 if (offset >= chip->ngpio)
3651 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3653 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3655 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3657 if (offset >= chip->ngpio)
3660 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3662 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3665 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3666 * @desc: gpio whose value will be returned
3668 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3669 * its ACTIVE_LOW status, or negative errno on failure.
3671 * This function is to be called from contexts that can sleep.
3673 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3675 might_sleep_if(extra_checks);
3676 VALIDATE_DESC(desc);
3677 return gpiod_get_raw_value_commit(desc);
3679 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3682 * gpiod_get_value_cansleep() - return a gpio's value
3683 * @desc: gpio whose value will be returned
3685 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3686 * account, or negative errno on failure.
3688 * This function is to be called from contexts that can sleep.
3690 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3694 might_sleep_if(extra_checks);
3695 VALIDATE_DESC(desc);
3696 value = gpiod_get_raw_value_commit(desc);
3700 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3705 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3708 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3709 * @array_size: number of elements in the descriptor array / value bitmap
3710 * @desc_array: array of GPIO descriptors whose values will be read
3711 * @array_info: information on applicability of fast bitmap processing path
3712 * @value_bitmap: bitmap to store the read values
3714 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3715 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3716 * else an error code.
3718 * This function is to be called from contexts that can sleep.
3720 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3721 struct gpio_desc **desc_array,
3722 struct gpio_array *array_info,
3723 unsigned long *value_bitmap)
3725 might_sleep_if(extra_checks);
3728 return gpiod_get_array_value_complex(true, true, array_size,
3729 desc_array, array_info,
3732 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3735 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3736 * @array_size: number of elements in the descriptor array / value bitmap
3737 * @desc_array: array of GPIO descriptors whose values will be read
3738 * @array_info: information on applicability of fast bitmap processing path
3739 * @value_bitmap: bitmap to store the read values
3741 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3742 * into account. Return 0 in case of success, else an error code.
3744 * This function is to be called from contexts that can sleep.
3746 int gpiod_get_array_value_cansleep(unsigned int array_size,
3747 struct gpio_desc **desc_array,
3748 struct gpio_array *array_info,
3749 unsigned long *value_bitmap)
3751 might_sleep_if(extra_checks);
3754 return gpiod_get_array_value_complex(false, true, array_size,
3755 desc_array, array_info,
3758 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3761 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3762 * @desc: gpio whose value will be assigned
3763 * @value: value to assign
3765 * Set the raw value of the GPIO, i.e. the value of its physical line without
3766 * regard for its ACTIVE_LOW status.
3768 * This function is to be called from contexts that can sleep.
3770 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3772 might_sleep_if(extra_checks);
3773 VALIDATE_DESC_VOID(desc);
3774 gpiod_set_raw_value_commit(desc, value);
3776 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3779 * gpiod_set_value_cansleep() - assign a gpio's value
3780 * @desc: gpio whose value will be assigned
3781 * @value: value to assign
3783 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3786 * This function is to be called from contexts that can sleep.
3788 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3790 might_sleep_if(extra_checks);
3791 VALIDATE_DESC_VOID(desc);
3792 gpiod_set_value_nocheck(desc, value);
3794 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3797 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3798 * @array_size: number of elements in the descriptor array / value bitmap
3799 * @desc_array: array of GPIO descriptors whose values will be assigned
3800 * @array_info: information on applicability of fast bitmap processing path
3801 * @value_bitmap: bitmap of values to assign
3803 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3804 * without regard for their ACTIVE_LOW status.
3806 * This function is to be called from contexts that can sleep.
3808 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3809 struct gpio_desc **desc_array,
3810 struct gpio_array *array_info,
3811 unsigned long *value_bitmap)
3813 might_sleep_if(extra_checks);
3816 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3817 array_info, value_bitmap);
3819 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3822 * gpiod_add_lookup_tables() - register GPIO device consumers
3823 * @tables: list of tables of consumers to register
3824 * @n: number of tables in the list
3826 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3830 mutex_lock(&gpio_lookup_lock);
3832 for (i = 0; i < n; i++)
3833 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3835 mutex_unlock(&gpio_lookup_lock);
3839 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3840 * @array_size: number of elements in the descriptor array / value bitmap
3841 * @desc_array: array of GPIO descriptors whose values will be assigned
3842 * @array_info: information on applicability of fast bitmap processing path
3843 * @value_bitmap: bitmap of values to assign
3845 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3848 * This function is to be called from contexts that can sleep.
3850 int gpiod_set_array_value_cansleep(unsigned int array_size,
3851 struct gpio_desc **desc_array,
3852 struct gpio_array *array_info,
3853 unsigned long *value_bitmap)
3855 might_sleep_if(extra_checks);
3858 return gpiod_set_array_value_complex(false, true, array_size,
3859 desc_array, array_info,
3862 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3865 * gpiod_add_lookup_table() - register GPIO device consumers
3866 * @table: table of consumers to register
3868 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3870 mutex_lock(&gpio_lookup_lock);
3872 list_add_tail(&table->list, &gpio_lookup_list);
3874 mutex_unlock(&gpio_lookup_lock);
3876 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3879 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3880 * @table: table of consumers to unregister
3882 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3884 mutex_lock(&gpio_lookup_lock);
3886 list_del(&table->list);
3888 mutex_unlock(&gpio_lookup_lock);
3890 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3893 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3894 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3896 void gpiod_add_hogs(struct gpiod_hog *hogs)
3898 struct gpio_chip *chip;
3899 struct gpiod_hog *hog;
3901 mutex_lock(&gpio_machine_hogs_mutex);
3903 for (hog = &hogs[0]; hog->chip_label; hog++) {
3904 list_add_tail(&hog->list, &gpio_machine_hogs);
3907 * The chip may have been registered earlier, so check if it
3908 * exists and, if so, try to hog the line now.
3910 chip = find_chip_by_name(hog->chip_label);
3912 gpiochip_machine_hog(chip, hog);
3915 mutex_unlock(&gpio_machine_hogs_mutex);
3917 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3919 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3921 const char *dev_id = dev ? dev_name(dev) : NULL;
3922 struct gpiod_lookup_table *table;
3924 mutex_lock(&gpio_lookup_lock);
3926 list_for_each_entry(table, &gpio_lookup_list, list) {
3927 if (table->dev_id && dev_id) {
3929 * Valid strings on both ends, must be identical to have
3932 if (!strcmp(table->dev_id, dev_id))
3936 * One of the pointers is NULL, so both must be to have
3939 if (dev_id == table->dev_id)
3946 mutex_unlock(&gpio_lookup_lock);
3950 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3951 unsigned int idx, unsigned long *flags)
3953 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3954 struct gpiod_lookup_table *table;
3955 struct gpiod_lookup *p;
3957 table = gpiod_find_lookup_table(dev);
3961 for (p = &table->table[0]; p->chip_label; p++) {
3962 struct gpio_chip *chip;
3964 /* idx must always match exactly */
3968 /* If the lookup entry has a con_id, require exact match */
3969 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3972 chip = find_chip_by_name(p->chip_label);
3976 * As the lookup table indicates a chip with
3977 * p->chip_label should exist, assume it may
3978 * still appear later and let the interested
3979 * consumer be probed again or let the Deferred
3980 * Probe infrastructure handle the error.
3982 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3984 return ERR_PTR(-EPROBE_DEFER);
3987 if (chip->ngpio <= p->chip_hwnum) {
3989 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3990 idx, chip->ngpio, chip->label);
3991 return ERR_PTR(-EINVAL);
3994 desc = gpiochip_get_desc(chip, p->chip_hwnum);
4003 static int dt_gpio_count(struct device *dev, const char *con_id)
4009 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
4011 snprintf(propname, sizeof(propname), "%s-%s",
4012 con_id, gpio_suffixes[i]);
4014 snprintf(propname, sizeof(propname), "%s",
4017 ret = of_gpio_named_count(dev->of_node, propname);
4021 return ret ? ret : -ENOENT;
4024 static int platform_gpio_count(struct device *dev, const char *con_id)
4026 struct gpiod_lookup_table *table;
4027 struct gpiod_lookup *p;
4028 unsigned int count = 0;
4030 table = gpiod_find_lookup_table(dev);
4034 for (p = &table->table[0]; p->chip_label; p++) {
4035 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4036 (!con_id && !p->con_id))
4046 * gpiod_count - return the number of GPIOs associated with a device / function
4047 * or -ENOENT if no GPIO has been assigned to the requested function
4048 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4049 * @con_id: function within the GPIO consumer
4051 int gpiod_count(struct device *dev, const char *con_id)
4053 int count = -ENOENT;
4055 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
4056 count = dt_gpio_count(dev, con_id);
4057 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
4058 count = acpi_gpio_count(dev, con_id);
4061 count = platform_gpio_count(dev, con_id);
4065 EXPORT_SYMBOL_GPL(gpiod_count);
4068 * gpiod_get - obtain a GPIO for a given GPIO function
4069 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4070 * @con_id: function within the GPIO consumer
4071 * @flags: optional GPIO initialization flags
4073 * Return the GPIO descriptor corresponding to the function con_id of device
4074 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4075 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4077 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4078 enum gpiod_flags flags)
4080 return gpiod_get_index(dev, con_id, 0, flags);
4082 EXPORT_SYMBOL_GPL(gpiod_get);
4085 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4086 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4087 * @con_id: function within the GPIO consumer
4088 * @flags: optional GPIO initialization flags
4090 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4091 * the requested function it will return NULL. This is convenient for drivers
4092 * that need to handle optional GPIOs.
4094 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4096 enum gpiod_flags flags)
4098 return gpiod_get_index_optional(dev, con_id, 0, flags);
4100 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4104 * gpiod_configure_flags - helper function to configure a given GPIO
4105 * @desc: gpio whose value will be assigned
4106 * @con_id: function within the GPIO consumer
4107 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4108 * of_find_gpio() or of_get_gpio_hog()
4109 * @dflags: gpiod_flags - optional GPIO initialization flags
4111 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4112 * requested function and/or index, or another IS_ERR() code if an error
4113 * occurred while trying to acquire the GPIO.
4115 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4116 unsigned long lflags, enum gpiod_flags dflags)
4120 if (lflags & GPIO_ACTIVE_LOW)
4121 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4123 if (lflags & GPIO_OPEN_DRAIN)
4124 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4125 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4127 * This enforces open drain mode from the consumer side.
4128 * This is necessary for some busses like I2C, but the lookup
4129 * should *REALLY* have specified them as open drain in the
4130 * first place, so print a little warning here.
4132 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4134 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4137 if (lflags & GPIO_OPEN_SOURCE)
4138 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4140 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
4142 "both pull-up and pull-down enabled, invalid configuration\n");
4146 if (lflags & GPIO_PULL_UP)
4147 set_bit(FLAG_PULL_UP, &desc->flags);
4148 else if (lflags & GPIO_PULL_DOWN)
4149 set_bit(FLAG_PULL_DOWN, &desc->flags);
4151 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4155 /* No particular flag request, return here... */
4156 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4157 pr_debug("no flags found for %s\n", con_id);
4162 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4163 status = gpiod_direction_output(desc,
4164 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4166 status = gpiod_direction_input(desc);
4172 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4173 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4174 * @con_id: function within the GPIO consumer
4175 * @idx: index of the GPIO to obtain in the consumer
4176 * @flags: optional GPIO initialization flags
4178 * This variant of gpiod_get() allows to access GPIOs other than the first
4179 * defined one for functions that define several GPIOs.
4181 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4182 * requested function and/or index, or another IS_ERR() code if an error
4183 * occurred while trying to acquire the GPIO.
4185 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4188 enum gpiod_flags flags)
4190 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4191 struct gpio_desc *desc = NULL;
4193 /* Maybe we have a device name, maybe not */
4194 const char *devname = dev ? dev_name(dev) : "?";
4196 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4199 /* Using device tree? */
4200 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4201 dev_dbg(dev, "using device tree for GPIO lookup\n");
4202 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4203 } else if (ACPI_COMPANION(dev)) {
4204 dev_dbg(dev, "using ACPI for GPIO lookup\n");
4205 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4210 * Either we are not using DT or ACPI, or their lookup did not return
4211 * a result. In that case, use platform lookup as a fallback.
4213 if (!desc || desc == ERR_PTR(-ENOENT)) {
4214 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4215 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4219 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4224 * If a connection label was passed use that, else attempt to use
4225 * the device name as label
4227 status = gpiod_request(desc, con_id ? con_id : devname);
4229 if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4231 * This happens when there are several consumers for
4232 * the same GPIO line: we just return here without
4233 * further initialization. It is a bit if a hack.
4234 * This is necessary to support fixed regulators.
4236 * FIXME: Make this more sane and safe.
4238 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4239 con_id ? con_id : devname);
4242 return ERR_PTR(status);
4246 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4248 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4250 return ERR_PTR(status);
4255 EXPORT_SYMBOL_GPL(gpiod_get_index);
4258 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
4259 * @node: handle of the OF node
4260 * @propname: name of the DT property representing the GPIO
4261 * @index: index of the GPIO to obtain for the consumer
4262 * @dflags: GPIO initialization flags
4263 * @label: label to attach to the requested GPIO
4266 * On successful request the GPIO pin is configured in accordance with
4269 * In case of error an ERR_PTR() is returned.
4271 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
4272 const char *propname, int index,
4273 enum gpiod_flags dflags,
4276 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4277 struct gpio_desc *desc;
4278 enum of_gpio_flags flags;
4279 bool active_low = false;
4280 bool single_ended = false;
4281 bool open_drain = false;
4282 bool transitory = false;
4285 desc = of_get_named_gpiod_flags(node, propname,
4288 if (!desc || IS_ERR(desc)) {
4292 active_low = flags & OF_GPIO_ACTIVE_LOW;
4293 single_ended = flags & OF_GPIO_SINGLE_ENDED;
4294 open_drain = flags & OF_GPIO_OPEN_DRAIN;
4295 transitory = flags & OF_GPIO_TRANSITORY;
4297 ret = gpiod_request(desc, label);
4298 if (ret == -EBUSY && (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4301 return ERR_PTR(ret);
4304 lflags |= GPIO_ACTIVE_LOW;
4308 lflags |= GPIO_OPEN_DRAIN;
4310 lflags |= GPIO_OPEN_SOURCE;
4314 lflags |= GPIO_TRANSITORY;
4316 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4319 return ERR_PTR(ret);
4324 EXPORT_SYMBOL(gpiod_get_from_of_node);
4327 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4328 * @fwnode: handle of the firmware node
4329 * @propname: name of the firmware property representing the GPIO
4330 * @index: index of the GPIO to obtain for the consumer
4331 * @dflags: GPIO initialization flags
4332 * @label: label to attach to the requested GPIO
4334 * This function can be used for drivers that get their configuration
4335 * from opaque firmware.
4337 * The function properly finds the corresponding GPIO using whatever is the
4338 * underlying firmware interface and then makes sure that the GPIO
4339 * descriptor is requested before it is returned to the caller.
4342 * On successful request the GPIO pin is configured in accordance with
4345 * In case of error an ERR_PTR() is returned.
4347 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4348 const char *propname, int index,
4349 enum gpiod_flags dflags,
4352 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4353 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4357 return ERR_PTR(-EINVAL);
4359 if (is_of_node(fwnode)) {
4360 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4365 } else if (is_acpi_node(fwnode)) {
4366 struct acpi_gpio_info info;
4368 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4372 acpi_gpio_update_gpiod_flags(&dflags, &info);
4373 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4376 /* Currently only ACPI takes this path */
4377 ret = gpiod_request(desc, label);
4379 return ERR_PTR(ret);
4381 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4384 return ERR_PTR(ret);
4389 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4392 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4394 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4395 * @con_id: function within the GPIO consumer
4396 * @index: index of the GPIO to obtain in the consumer
4397 * @flags: optional GPIO initialization flags
4399 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4400 * specified index was assigned to the requested function it will return NULL.
4401 * This is convenient for drivers that need to handle optional GPIOs.
4403 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4406 enum gpiod_flags flags)
4408 struct gpio_desc *desc;
4410 desc = gpiod_get_index(dev, con_id, index, flags);
4412 if (PTR_ERR(desc) == -ENOENT)
4418 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4421 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4422 * @desc: gpio whose value will be assigned
4423 * @name: gpio line name
4424 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4425 * of_find_gpio() or of_get_gpio_hog()
4426 * @dflags: gpiod_flags - optional GPIO initialization flags
4428 int gpiod_hog(struct gpio_desc *desc, const char *name,
4429 unsigned long lflags, enum gpiod_flags dflags)
4431 struct gpio_chip *chip;
4432 struct gpio_desc *local_desc;
4436 chip = gpiod_to_chip(desc);
4437 hwnum = gpio_chip_hwgpio(desc);
4439 local_desc = gpiochip_request_own_desc(chip, hwnum, name,
4441 if (IS_ERR(local_desc)) {
4442 status = PTR_ERR(local_desc);
4443 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4444 name, chip->label, hwnum, status);
4448 /* Mark GPIO as hogged so it can be identified and removed later */
4449 set_bit(FLAG_IS_HOGGED, &desc->flags);
4451 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4452 desc_to_gpio(desc), name,
4453 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4454 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4455 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4461 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4462 * @chip: gpio chip to act on
4464 static void gpiochip_free_hogs(struct gpio_chip *chip)
4468 for (id = 0; id < chip->ngpio; id++) {
4469 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4470 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4475 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4476 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4477 * @con_id: function within the GPIO consumer
4478 * @flags: optional GPIO initialization flags
4480 * This function acquires all the GPIOs defined under a given function.
4482 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4483 * no GPIO has been assigned to the requested function, or another IS_ERR()
4484 * code if an error occurred while trying to acquire the GPIOs.
4486 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4488 enum gpiod_flags flags)
4490 struct gpio_desc *desc;
4491 struct gpio_descs *descs;
4492 struct gpio_array *array_info = NULL;
4493 struct gpio_chip *chip;
4494 int count, bitmap_size;
4496 count = gpiod_count(dev, con_id);
4498 return ERR_PTR(count);
4500 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4502 return ERR_PTR(-ENOMEM);
4504 for (descs->ndescs = 0; descs->ndescs < count; ) {
4505 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4507 gpiod_put_array(descs);
4508 return ERR_CAST(desc);
4511 descs->desc[descs->ndescs] = desc;
4513 chip = gpiod_to_chip(desc);
4515 * If pin hardware number of array member 0 is also 0, select
4516 * its chip as a candidate for fast bitmap processing path.
4518 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4519 struct gpio_descs *array;
4521 bitmap_size = BITS_TO_LONGS(chip->ngpio > count ?
4522 chip->ngpio : count);
4524 array = kzalloc(struct_size(descs, desc, count) +
4525 struct_size(array_info, invert_mask,
4526 3 * bitmap_size), GFP_KERNEL);
4528 gpiod_put_array(descs);
4529 return ERR_PTR(-ENOMEM);
4532 memcpy(array, descs,
4533 struct_size(descs, desc, descs->ndescs + 1));
4537 array_info = (void *)(descs->desc + count);
4538 array_info->get_mask = array_info->invert_mask +
4540 array_info->set_mask = array_info->get_mask +
4543 array_info->desc = descs->desc;
4544 array_info->size = count;
4545 array_info->chip = chip;
4546 bitmap_set(array_info->get_mask, descs->ndescs,
4547 count - descs->ndescs);
4548 bitmap_set(array_info->set_mask, descs->ndescs,
4549 count - descs->ndescs);
4550 descs->info = array_info;
4552 /* Unmark array members which don't belong to the 'fast' chip */
4553 if (array_info && array_info->chip != chip) {
4554 __clear_bit(descs->ndescs, array_info->get_mask);
4555 __clear_bit(descs->ndescs, array_info->set_mask);
4558 * Detect array members which belong to the 'fast' chip
4559 * but their pins are not in hardware order.
4561 else if (array_info &&
4562 gpio_chip_hwgpio(desc) != descs->ndescs) {
4564 * Don't use fast path if all array members processed so
4565 * far belong to the same chip as this one but its pin
4566 * hardware number is different from its array index.
4568 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4571 __clear_bit(descs->ndescs,
4572 array_info->get_mask);
4573 __clear_bit(descs->ndescs,
4574 array_info->set_mask);
4576 } else if (array_info) {
4577 /* Exclude open drain or open source from fast output */
4578 if (gpiochip_line_is_open_drain(chip, descs->ndescs) ||
4579 gpiochip_line_is_open_source(chip, descs->ndescs))
4580 __clear_bit(descs->ndescs,
4581 array_info->set_mask);
4582 /* Identify 'fast' pins which require invertion */
4583 if (gpiod_is_active_low(desc))
4584 __set_bit(descs->ndescs,
4585 array_info->invert_mask);
4592 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4593 array_info->chip->label, array_info->size,
4594 *array_info->get_mask, *array_info->set_mask,
4595 *array_info->invert_mask);
4598 EXPORT_SYMBOL_GPL(gpiod_get_array);
4601 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4603 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4604 * @con_id: function within the GPIO consumer
4605 * @flags: optional GPIO initialization flags
4607 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4608 * assigned to the requested function it will return NULL.
4610 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4612 enum gpiod_flags flags)
4614 struct gpio_descs *descs;
4616 descs = gpiod_get_array(dev, con_id, flags);
4617 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4622 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4625 * gpiod_put - dispose of a GPIO descriptor
4626 * @desc: GPIO descriptor to dispose of
4628 * No descriptor can be used after gpiod_put() has been called on it.
4630 void gpiod_put(struct gpio_desc *desc)
4635 EXPORT_SYMBOL_GPL(gpiod_put);
4638 * gpiod_put_array - dispose of multiple GPIO descriptors
4639 * @descs: struct gpio_descs containing an array of descriptors
4641 void gpiod_put_array(struct gpio_descs *descs)
4645 for (i = 0; i < descs->ndescs; i++)
4646 gpiod_put(descs->desc[i]);
4650 EXPORT_SYMBOL_GPL(gpiod_put_array);
4652 static int __init gpiolib_dev_init(void)
4656 /* Register GPIO sysfs bus */
4657 ret = bus_register(&gpio_bus_type);
4659 pr_err("gpiolib: could not register GPIO bus type\n");
4663 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4665 pr_err("gpiolib: failed to allocate char dev region\n");
4666 bus_unregister(&gpio_bus_type);
4668 gpiolib_initialized = true;
4669 gpiochip_setup_devs();
4673 core_initcall(gpiolib_dev_init);
4675 #ifdef CONFIG_DEBUG_FS
4677 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4680 struct gpio_chip *chip = gdev->chip;
4681 unsigned gpio = gdev->base;
4682 struct gpio_desc *gdesc = &gdev->descs[0];
4687 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4688 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4690 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4696 gpiod_get_direction(gdesc);
4697 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4698 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4699 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4700 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4701 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4702 is_out ? "out" : "in ",
4703 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4704 is_irq ? "IRQ " : "",
4705 active_low ? "ACTIVE LOW" : "");
4706 seq_printf(s, "\n");
4710 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4712 unsigned long flags;
4713 struct gpio_device *gdev = NULL;
4714 loff_t index = *pos;
4718 spin_lock_irqsave(&gpio_lock, flags);
4719 list_for_each_entry(gdev, &gpio_devices, list)
4721 spin_unlock_irqrestore(&gpio_lock, flags);
4724 spin_unlock_irqrestore(&gpio_lock, flags);
4729 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4731 unsigned long flags;
4732 struct gpio_device *gdev = v;
4735 spin_lock_irqsave(&gpio_lock, flags);
4736 if (list_is_last(&gdev->list, &gpio_devices))
4739 ret = list_entry(gdev->list.next, struct gpio_device, list);
4740 spin_unlock_irqrestore(&gpio_lock, flags);
4748 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4752 static int gpiolib_seq_show(struct seq_file *s, void *v)
4754 struct gpio_device *gdev = v;
4755 struct gpio_chip *chip = gdev->chip;
4756 struct device *parent;
4759 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4760 dev_name(&gdev->dev));
4764 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4765 dev_name(&gdev->dev),
4766 gdev->base, gdev->base + gdev->ngpio - 1);
4767 parent = chip->parent;
4769 seq_printf(s, ", parent: %s/%s",
4770 parent->bus ? parent->bus->name : "no-bus",
4773 seq_printf(s, ", %s", chip->label);
4774 if (chip->can_sleep)
4775 seq_printf(s, ", can sleep");
4776 seq_printf(s, ":\n");
4779 chip->dbg_show(s, chip);
4781 gpiolib_dbg_show(s, gdev);
4786 static const struct seq_operations gpiolib_seq_ops = {
4787 .start = gpiolib_seq_start,
4788 .next = gpiolib_seq_next,
4789 .stop = gpiolib_seq_stop,
4790 .show = gpiolib_seq_show,
4793 static int gpiolib_open(struct inode *inode, struct file *file)
4795 return seq_open(file, &gpiolib_seq_ops);
4798 static const struct file_operations gpiolib_operations = {
4799 .owner = THIS_MODULE,
4800 .open = gpiolib_open,
4802 .llseek = seq_lseek,
4803 .release = seq_release,
4806 static int __init gpiolib_debugfs_init(void)
4808 /* /sys/kernel/debug/gpio */
4809 debugfs_create_file("gpio", S_IFREG | S_IRUGO, NULL, NULL,
4810 &gpiolib_operations);
4813 subsys_initcall(gpiolib_debugfs_init);
4815 #endif /* DEBUG_FS */