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 |= IRQF_TRIGGER_RISING;
960 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
961 irqflags |= IRQF_TRIGGER_FALLING;
962 irqflags |= IRQF_ONESHOT;
964 INIT_KFIFO(le->events);
965 init_waitqueue_head(&le->wait);
966 mutex_init(&le->read_lock);
968 /* Request a thread to read the events */
969 ret = request_threaded_irq(le->irq,
970 lineevent_irq_handler,
971 lineevent_irq_thread,
978 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
984 file = anon_inode_getfile("gpio-event",
987 O_RDONLY | O_CLOEXEC);
990 goto out_put_unused_fd;
994 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
996 * fput() will trigger the release() callback, so do not go onto
997 * the regular error cleanup path here.
1004 fd_install(fd, file);
1011 free_irq(le->irq, le);
1013 gpiod_free(le->desc);
1018 put_device(&gdev->dev);
1023 * gpio_ioctl() - ioctl handler for the GPIO chardev
1025 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1027 struct gpio_device *gdev = filp->private_data;
1028 struct gpio_chip *chip = gdev->chip;
1029 void __user *ip = (void __user *)arg;
1031 /* We fail any subsequent ioctl():s when the chip is gone */
1035 /* Fill in the struct and pass to userspace */
1036 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1037 struct gpiochip_info chipinfo;
1039 memset(&chipinfo, 0, sizeof(chipinfo));
1041 strncpy(chipinfo.name, dev_name(&gdev->dev),
1042 sizeof(chipinfo.name));
1043 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1044 strncpy(chipinfo.label, gdev->label,
1045 sizeof(chipinfo.label));
1046 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1047 chipinfo.lines = gdev->ngpio;
1048 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1051 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1052 struct gpioline_info lineinfo;
1053 struct gpio_desc *desc;
1055 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1057 if (lineinfo.line_offset >= gdev->ngpio)
1060 desc = &gdev->descs[lineinfo.line_offset];
1062 strncpy(lineinfo.name, desc->name,
1063 sizeof(lineinfo.name));
1064 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1066 lineinfo.name[0] = '\0';
1069 strncpy(lineinfo.consumer, desc->label,
1070 sizeof(lineinfo.consumer));
1071 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1073 lineinfo.consumer[0] = '\0';
1077 * Userspace only need to know that the kernel is using
1078 * this GPIO so it can't use it.
1081 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1082 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1083 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1084 test_bit(FLAG_EXPORT, &desc->flags) ||
1085 test_bit(FLAG_SYSFS, &desc->flags))
1086 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1087 if (test_bit(FLAG_IS_OUT, &desc->flags))
1088 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1089 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1090 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1091 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1092 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1093 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1094 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1096 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1099 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1100 return linehandle_create(gdev, ip);
1101 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1102 return lineevent_create(gdev, ip);
1107 #ifdef CONFIG_COMPAT
1108 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1111 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1116 * gpio_chrdev_open() - open the chardev for ioctl operations
1117 * @inode: inode for this chardev
1118 * @filp: file struct for storing private data
1119 * Returns 0 on success
1121 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1123 struct gpio_device *gdev = container_of(inode->i_cdev,
1124 struct gpio_device, chrdev);
1126 /* Fail on open if the backing gpiochip is gone */
1129 get_device(&gdev->dev);
1130 filp->private_data = gdev;
1132 return nonseekable_open(inode, filp);
1136 * gpio_chrdev_release() - close chardev after ioctl operations
1137 * @inode: inode for this chardev
1138 * @filp: file struct for storing private data
1139 * Returns 0 on success
1141 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1143 struct gpio_device *gdev = container_of(inode->i_cdev,
1144 struct gpio_device, chrdev);
1146 put_device(&gdev->dev);
1151 static const struct file_operations gpio_fileops = {
1152 .release = gpio_chrdev_release,
1153 .open = gpio_chrdev_open,
1154 .owner = THIS_MODULE,
1155 .llseek = no_llseek,
1156 .unlocked_ioctl = gpio_ioctl,
1157 #ifdef CONFIG_COMPAT
1158 .compat_ioctl = gpio_ioctl_compat,
1162 static void gpiodevice_release(struct device *dev)
1164 struct gpio_device *gdev = dev_get_drvdata(dev);
1166 list_del(&gdev->list);
1167 ida_simple_remove(&gpio_ida, gdev->id);
1168 kfree_const(gdev->label);
1173 static int gpiochip_setup_dev(struct gpio_device *gdev)
1177 cdev_init(&gdev->chrdev, &gpio_fileops);
1178 gdev->chrdev.owner = THIS_MODULE;
1179 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1181 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1185 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1186 MAJOR(gpio_devt), gdev->id);
1188 status = gpiochip_sysfs_register(gdev);
1190 goto err_remove_device;
1192 /* From this point, the .release() function cleans up gpio_device */
1193 gdev->dev.release = gpiodevice_release;
1194 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1195 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1196 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1201 cdev_device_del(&gdev->chrdev, &gdev->dev);
1205 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1207 struct gpio_desc *desc;
1210 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1212 pr_err("%s: unable to get GPIO desc: %ld\n",
1213 __func__, PTR_ERR(desc));
1217 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1220 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1222 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1223 __func__, chip->label, hog->chip_hwnum, rv);
1226 static void machine_gpiochip_add(struct gpio_chip *chip)
1228 struct gpiod_hog *hog;
1230 mutex_lock(&gpio_machine_hogs_mutex);
1232 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1233 if (!strcmp(chip->label, hog->chip_label))
1234 gpiochip_machine_hog(chip, hog);
1237 mutex_unlock(&gpio_machine_hogs_mutex);
1240 static void gpiochip_setup_devs(void)
1242 struct gpio_device *gdev;
1245 list_for_each_entry(gdev, &gpio_devices, list) {
1246 err = gpiochip_setup_dev(gdev);
1248 pr_err("%s: Failed to initialize gpio device (%d)\n",
1249 dev_name(&gdev->dev), err);
1253 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1254 struct lock_class_key *lock_key,
1255 struct lock_class_key *request_key)
1257 unsigned long flags;
1260 int base = chip->base;
1261 struct gpio_device *gdev;
1264 * First: allocate and populate the internal stat container, and
1265 * set up the struct device.
1267 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1270 gdev->dev.bus = &gpio_bus_type;
1272 chip->gpiodev = gdev;
1274 gdev->dev.parent = chip->parent;
1275 gdev->dev.of_node = chip->parent->of_node;
1278 #ifdef CONFIG_OF_GPIO
1279 /* If the gpiochip has an assigned OF node this takes precedence */
1281 gdev->dev.of_node = chip->of_node;
1283 chip->of_node = gdev->dev.of_node;
1286 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1291 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1292 device_initialize(&gdev->dev);
1293 dev_set_drvdata(&gdev->dev, gdev);
1294 if (chip->parent && chip->parent->driver)
1295 gdev->owner = chip->parent->driver->owner;
1296 else if (chip->owner)
1297 /* TODO: remove chip->owner */
1298 gdev->owner = chip->owner;
1300 gdev->owner = THIS_MODULE;
1302 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1308 if (chip->ngpio == 0) {
1309 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1311 goto err_free_descs;
1314 if (chip->ngpio > FASTPATH_NGPIO)
1315 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1316 chip->ngpio, FASTPATH_NGPIO);
1318 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1321 goto err_free_descs;
1324 gdev->ngpio = chip->ngpio;
1327 spin_lock_irqsave(&gpio_lock, flags);
1330 * TODO: this allocates a Linux GPIO number base in the global
1331 * GPIO numberspace for this chip. In the long run we want to
1332 * get *rid* of this numberspace and use only descriptors, but
1333 * it may be a pipe dream. It will not happen before we get rid
1334 * of the sysfs interface anyways.
1337 base = gpiochip_find_base(chip->ngpio);
1340 spin_unlock_irqrestore(&gpio_lock, flags);
1341 goto err_free_label;
1344 * TODO: it should not be necessary to reflect the assigned
1345 * base outside of the GPIO subsystem. Go over drivers and
1346 * see if anyone makes use of this, else drop this and assign
1353 status = gpiodev_add_to_list(gdev);
1355 spin_unlock_irqrestore(&gpio_lock, flags);
1356 goto err_free_label;
1359 spin_unlock_irqrestore(&gpio_lock, flags);
1361 for (i = 0; i < chip->ngpio; i++)
1362 gdev->descs[i].gdev = gdev;
1364 #ifdef CONFIG_PINCTRL
1365 INIT_LIST_HEAD(&gdev->pin_ranges);
1368 status = gpiochip_set_desc_names(chip);
1370 goto err_remove_from_list;
1372 status = gpiochip_irqchip_init_valid_mask(chip);
1374 goto err_remove_from_list;
1376 status = gpiochip_alloc_valid_mask(chip);
1378 goto err_remove_irqchip_mask;
1380 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1382 goto err_remove_chip;
1384 status = of_gpiochip_add(chip);
1386 goto err_remove_chip;
1388 status = gpiochip_init_valid_mask(chip);
1390 goto err_remove_chip;
1392 for (i = 0; i < chip->ngpio; i++) {
1393 struct gpio_desc *desc = &gdev->descs[i];
1395 if (chip->get_direction && gpiochip_line_is_valid(chip, i))
1396 desc->flags = !chip->get_direction(chip, i) ?
1397 (1 << FLAG_IS_OUT) : 0;
1399 desc->flags = !chip->direction_input ?
1400 (1 << FLAG_IS_OUT) : 0;
1403 acpi_gpiochip_add(chip);
1405 machine_gpiochip_add(chip);
1408 * By first adding the chardev, and then adding the device,
1409 * we get a device node entry in sysfs under
1410 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1411 * coldplug of device nodes and other udev business.
1412 * We can do this only if gpiolib has been initialized.
1413 * Otherwise, defer until later.
1415 if (gpiolib_initialized) {
1416 status = gpiochip_setup_dev(gdev);
1418 goto err_remove_chip;
1423 acpi_gpiochip_remove(chip);
1424 gpiochip_free_hogs(chip);
1425 of_gpiochip_remove(chip);
1426 gpiochip_free_valid_mask(chip);
1427 err_remove_irqchip_mask:
1428 gpiochip_irqchip_free_valid_mask(chip);
1429 err_remove_from_list:
1430 spin_lock_irqsave(&gpio_lock, flags);
1431 list_del(&gdev->list);
1432 spin_unlock_irqrestore(&gpio_lock, flags);
1434 kfree_const(gdev->label);
1438 ida_simple_remove(&gpio_ida, gdev->id);
1440 /* failures here can mean systems won't boot... */
1441 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1442 gdev->base, gdev->base + gdev->ngpio - 1,
1443 chip->label ? : "generic", status);
1447 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1450 * gpiochip_get_data() - get per-subdriver data for the chip
1454 * The per-subdriver data for the chip.
1456 void *gpiochip_get_data(struct gpio_chip *chip)
1458 return chip->gpiodev->data;
1460 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1463 * gpiochip_remove() - unregister a gpio_chip
1464 * @chip: the chip to unregister
1466 * A gpio_chip with any GPIOs still requested may not be removed.
1468 void gpiochip_remove(struct gpio_chip *chip)
1470 struct gpio_device *gdev = chip->gpiodev;
1471 struct gpio_desc *desc;
1472 unsigned long flags;
1474 bool requested = false;
1476 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1477 gpiochip_sysfs_unregister(gdev);
1478 gpiochip_free_hogs(chip);
1479 /* Numb the device, cancelling all outstanding operations */
1481 gpiochip_irqchip_remove(chip);
1482 acpi_gpiochip_remove(chip);
1483 gpiochip_remove_pin_ranges(chip);
1484 of_gpiochip_remove(chip);
1485 gpiochip_free_valid_mask(chip);
1487 * We accept no more calls into the driver from this point, so
1488 * NULL the driver data pointer
1492 spin_lock_irqsave(&gpio_lock, flags);
1493 for (i = 0; i < gdev->ngpio; i++) {
1494 desc = &gdev->descs[i];
1495 if (test_bit(FLAG_REQUESTED, &desc->flags))
1498 spin_unlock_irqrestore(&gpio_lock, flags);
1501 dev_crit(&gdev->dev,
1502 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1505 * The gpiochip side puts its use of the device to rest here:
1506 * if there are no userspace clients, the chardev and device will
1507 * be removed, else it will be dangling until the last user is
1510 cdev_device_del(&gdev->chrdev, &gdev->dev);
1511 put_device(&gdev->dev);
1513 EXPORT_SYMBOL_GPL(gpiochip_remove);
1515 static void devm_gpio_chip_release(struct device *dev, void *res)
1517 struct gpio_chip *chip = *(struct gpio_chip **)res;
1519 gpiochip_remove(chip);
1523 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1524 * @dev: pointer to the device that gpio_chip belongs to.
1525 * @chip: the chip to register, with chip->base initialized
1526 * @data: driver-private data associated with this chip
1528 * Context: potentially before irqs will work
1530 * The gpio chip automatically be released when the device is unbound.
1533 * A negative errno if the chip can't be registered, such as because the
1534 * chip->base is invalid or already associated with a different chip.
1535 * Otherwise it returns zero as a success code.
1537 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1540 struct gpio_chip **ptr;
1543 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1548 ret = gpiochip_add_data(chip, data);
1555 devres_add(dev, ptr);
1559 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1562 * gpiochip_find() - iterator for locating a specific gpio_chip
1563 * @data: data to pass to match function
1564 * @match: Callback function to check gpio_chip
1566 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1567 * determined by a user supplied @match callback. The callback should return
1568 * 0 if the device doesn't match and non-zero if it does. If the callback is
1569 * non-zero, this function will return to the caller and not iterate over any
1572 struct gpio_chip *gpiochip_find(void *data,
1573 int (*match)(struct gpio_chip *chip,
1576 struct gpio_device *gdev;
1577 struct gpio_chip *chip = NULL;
1578 unsigned long flags;
1580 spin_lock_irqsave(&gpio_lock, flags);
1581 list_for_each_entry(gdev, &gpio_devices, list)
1582 if (gdev->chip && match(gdev->chip, data)) {
1587 spin_unlock_irqrestore(&gpio_lock, flags);
1591 EXPORT_SYMBOL_GPL(gpiochip_find);
1593 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1595 const char *name = data;
1597 return !strcmp(chip->label, name);
1600 static struct gpio_chip *find_chip_by_name(const char *name)
1602 return gpiochip_find((void *)name, gpiochip_match_name);
1605 #ifdef CONFIG_GPIOLIB_IRQCHIP
1608 * The following is irqchip helper code for gpiochips.
1611 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1613 if (!gpiochip->irq.need_valid_mask)
1616 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1617 if (!gpiochip->irq.valid_mask)
1623 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1625 kfree(gpiochip->irq.valid_mask);
1626 gpiochip->irq.valid_mask = NULL;
1629 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1630 unsigned int offset)
1632 if (!gpiochip_line_is_valid(gpiochip, offset))
1634 /* No mask means all valid */
1635 if (likely(!gpiochip->irq.valid_mask))
1637 return test_bit(offset, gpiochip->irq.valid_mask);
1639 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1642 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1643 * @gpiochip: the gpiochip to set the irqchip chain to
1644 * @parent_irq: the irq number corresponding to the parent IRQ for this
1646 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1647 * coming out of the gpiochip. If the interrupt is nested rather than
1648 * cascaded, pass NULL in this handler argument
1650 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1651 unsigned int parent_irq,
1652 irq_flow_handler_t parent_handler)
1654 if (!gpiochip->irq.domain) {
1655 chip_err(gpiochip, "called %s before setting up irqchip\n",
1660 if (parent_handler) {
1661 if (gpiochip->can_sleep) {
1663 "you cannot have chained interrupts on a chip that may sleep\n");
1667 * The parent irqchip is already using the chip_data for this
1668 * irqchip, so our callbacks simply use the handler_data.
1670 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1673 gpiochip->irq.parent_irq = parent_irq;
1674 gpiochip->irq.parents = &gpiochip->irq.parent_irq;
1675 gpiochip->irq.num_parents = 1;
1680 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1681 * @gpiochip: the gpiochip to set the irqchip chain to
1682 * @irqchip: the irqchip to chain to the gpiochip
1683 * @parent_irq: the irq number corresponding to the parent IRQ for this
1685 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1686 * coming out of the gpiochip.
1688 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1689 struct irq_chip *irqchip,
1690 unsigned int parent_irq,
1691 irq_flow_handler_t parent_handler)
1693 if (gpiochip->irq.threaded) {
1694 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1698 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1700 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1703 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1704 * @gpiochip: the gpiochip to set the irqchip nested handler to
1705 * @irqchip: the irqchip to nest to the gpiochip
1706 * @parent_irq: the irq number corresponding to the parent IRQ for this
1709 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1710 struct irq_chip *irqchip,
1711 unsigned int parent_irq)
1713 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1715 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1718 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1719 * @d: the irqdomain used by this irqchip
1720 * @irq: the global irq number used by this GPIO irqchip irq
1721 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1723 * This function will set up the mapping for a certain IRQ line on a
1724 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1725 * stored inside the gpiochip.
1727 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1728 irq_hw_number_t hwirq)
1730 struct gpio_chip *chip = d->host_data;
1733 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1736 irq_set_chip_data(irq, chip);
1738 * This lock class tells lockdep that GPIO irqs are in a different
1739 * category than their parents, so it won't report false recursion.
1741 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1742 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1743 /* Chips that use nested thread handlers have them marked */
1744 if (chip->irq.threaded)
1745 irq_set_nested_thread(irq, 1);
1746 irq_set_noprobe(irq);
1748 if (chip->irq.num_parents == 1)
1749 err = irq_set_parent(irq, chip->irq.parents[0]);
1750 else if (chip->irq.map)
1751 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1757 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1758 * is passed as default type.
1760 if (chip->irq.default_type != IRQ_TYPE_NONE)
1761 irq_set_irq_type(irq, chip->irq.default_type);
1765 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1767 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1769 struct gpio_chip *chip = d->host_data;
1771 if (chip->irq.threaded)
1772 irq_set_nested_thread(irq, 0);
1773 irq_set_chip_and_handler(irq, NULL, NULL);
1774 irq_set_chip_data(irq, NULL);
1776 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1778 static const struct irq_domain_ops gpiochip_domain_ops = {
1779 .map = gpiochip_irq_map,
1780 .unmap = gpiochip_irq_unmap,
1781 /* Virtually all GPIO irqchips are twocell:ed */
1782 .xlate = irq_domain_xlate_twocell,
1786 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1787 * @domain: The IRQ domain used by this IRQ chip
1788 * @data: Outermost irq_data associated with the IRQ
1789 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1791 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1792 * used as the activate function for the &struct irq_domain_ops. The host_data
1793 * for the IRQ domain must be the &struct gpio_chip.
1795 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1796 struct irq_data *data, bool reserve)
1798 struct gpio_chip *chip = domain->host_data;
1800 return gpiochip_lock_as_irq(chip, data->hwirq);
1802 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1805 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1806 * @domain: The IRQ domain used by this IRQ chip
1807 * @data: Outermost irq_data associated with the IRQ
1809 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1810 * be used as the deactivate function for the &struct irq_domain_ops. The
1811 * host_data for the IRQ domain must be the &struct gpio_chip.
1813 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1814 struct irq_data *data)
1816 struct gpio_chip *chip = domain->host_data;
1818 return gpiochip_unlock_as_irq(chip, data->hwirq);
1820 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1822 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1824 if (!gpiochip_irqchip_irq_valid(chip, offset))
1827 return irq_create_mapping(chip->irq.domain, offset);
1830 static int gpiochip_irq_reqres(struct irq_data *d)
1832 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1834 return gpiochip_reqres_irq(chip, d->hwirq);
1837 static void gpiochip_irq_relres(struct irq_data *d)
1839 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1841 gpiochip_relres_irq(chip, d->hwirq);
1844 static void gpiochip_irq_enable(struct irq_data *d)
1846 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1848 gpiochip_enable_irq(chip, d->hwirq);
1849 if (chip->irq.irq_enable)
1850 chip->irq.irq_enable(d);
1852 chip->irq.chip->irq_unmask(d);
1855 static void gpiochip_irq_disable(struct irq_data *d)
1857 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1859 if (chip->irq.irq_disable)
1860 chip->irq.irq_disable(d);
1862 chip->irq.chip->irq_mask(d);
1863 gpiochip_disable_irq(chip, d->hwirq);
1866 static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
1868 struct irq_chip *irqchip = gpiochip->irq.chip;
1870 if (!irqchip->irq_request_resources &&
1871 !irqchip->irq_release_resources) {
1872 irqchip->irq_request_resources = gpiochip_irq_reqres;
1873 irqchip->irq_release_resources = gpiochip_irq_relres;
1875 if (WARN_ON(gpiochip->irq.irq_enable))
1877 /* Check if the irqchip already has this hook... */
1878 if (irqchip->irq_enable == gpiochip_irq_enable) {
1880 * ...and if so, give a gentle warning that this is bad
1884 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1887 gpiochip->irq.irq_enable = irqchip->irq_enable;
1888 gpiochip->irq.irq_disable = irqchip->irq_disable;
1889 irqchip->irq_enable = gpiochip_irq_enable;
1890 irqchip->irq_disable = gpiochip_irq_disable;
1894 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1895 * @gpiochip: the GPIO chip to add the IRQ chip to
1896 * @lock_key: lockdep class for IRQ lock
1897 * @request_key: lockdep class for IRQ request
1899 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1900 struct lock_class_key *lock_key,
1901 struct lock_class_key *request_key)
1903 struct irq_chip *irqchip = gpiochip->irq.chip;
1904 const struct irq_domain_ops *ops;
1905 struct device_node *np;
1912 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1913 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1917 np = gpiochip->gpiodev->dev.of_node;
1918 type = gpiochip->irq.default_type;
1921 * Specifying a default trigger is a terrible idea if DT or ACPI is
1922 * used to configure the interrupts, as you may end up with
1923 * conflicting triggers. Tell the user, and reset to NONE.
1925 if (WARN(np && type != IRQ_TYPE_NONE,
1926 "%s: Ignoring %u default trigger\n", np->full_name, type))
1927 type = IRQ_TYPE_NONE;
1929 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1930 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1931 "Ignoring %u default trigger\n", type);
1932 type = IRQ_TYPE_NONE;
1935 gpiochip->to_irq = gpiochip_to_irq;
1936 gpiochip->irq.default_type = type;
1937 gpiochip->irq.lock_key = lock_key;
1938 gpiochip->irq.request_key = request_key;
1940 if (gpiochip->irq.domain_ops)
1941 ops = gpiochip->irq.domain_ops;
1943 ops = &gpiochip_domain_ops;
1945 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1946 gpiochip->irq.first,
1948 if (!gpiochip->irq.domain)
1951 if (gpiochip->irq.parent_handler) {
1952 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1954 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1956 * The parent IRQ chip is already using the chip_data
1957 * for this IRQ chip, so our callbacks simply use the
1960 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1961 gpiochip->irq.parent_handler,
1966 gpiochip_set_irq_hooks(gpiochip);
1968 acpi_gpiochip_request_interrupts(gpiochip);
1974 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1975 * @gpiochip: the gpiochip to remove the irqchip from
1977 * This is called only from gpiochip_remove()
1979 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1981 struct irq_chip *irqchip = gpiochip->irq.chip;
1982 unsigned int offset;
1984 acpi_gpiochip_free_interrupts(gpiochip);
1986 if (irqchip && gpiochip->irq.parent_handler) {
1987 struct gpio_irq_chip *irq = &gpiochip->irq;
1990 for (i = 0; i < irq->num_parents; i++)
1991 irq_set_chained_handler_and_data(irq->parents[i],
1995 /* Remove all IRQ mappings and delete the domain */
1996 if (gpiochip->irq.domain) {
1999 for (offset = 0; offset < gpiochip->ngpio; offset++) {
2000 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
2003 irq = irq_find_mapping(gpiochip->irq.domain, offset);
2004 irq_dispose_mapping(irq);
2007 irq_domain_remove(gpiochip->irq.domain);
2011 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2012 irqchip->irq_request_resources = NULL;
2013 irqchip->irq_release_resources = NULL;
2015 if (irqchip->irq_enable == gpiochip_irq_enable) {
2016 irqchip->irq_enable = gpiochip->irq.irq_enable;
2017 irqchip->irq_disable = gpiochip->irq.irq_disable;
2020 gpiochip->irq.irq_enable = NULL;
2021 gpiochip->irq.irq_disable = NULL;
2022 gpiochip->irq.chip = NULL;
2024 gpiochip_irqchip_free_valid_mask(gpiochip);
2028 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2029 * @gpiochip: the gpiochip to add the irqchip to
2030 * @irqchip: the irqchip to add to the gpiochip
2031 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2032 * allocate gpiochip irqs from
2033 * @handler: the irq handler to use (often a predefined irq core function)
2034 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2035 * to have the core avoid setting up any default type in the hardware.
2036 * @threaded: whether this irqchip uses a nested thread handler
2037 * @lock_key: lockdep class for IRQ lock
2038 * @request_key: lockdep class for IRQ request
2040 * This function closely associates a certain irqchip with a certain
2041 * gpiochip, providing an irq domain to translate the local IRQs to
2042 * global irqs in the gpiolib core, and making sure that the gpiochip
2043 * is passed as chip data to all related functions. Driver callbacks
2044 * need to use gpiochip_get_data() to get their local state containers back
2045 * from the gpiochip passed as chip data. An irqdomain will be stored
2046 * in the gpiochip that shall be used by the driver to handle IRQ number
2047 * translation. The gpiochip will need to be initialized and registered
2048 * before calling this function.
2050 * This function will handle two cell:ed simple IRQs and assumes all
2051 * the pins on the gpiochip can generate a unique IRQ. Everything else
2052 * need to be open coded.
2054 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2055 struct irq_chip *irqchip,
2056 unsigned int first_irq,
2057 irq_flow_handler_t handler,
2060 struct lock_class_key *lock_key,
2061 struct lock_class_key *request_key)
2063 struct device_node *of_node;
2065 if (!gpiochip || !irqchip)
2068 if (!gpiochip->parent) {
2069 pr_err("missing gpiochip .dev parent pointer\n");
2072 gpiochip->irq.threaded = threaded;
2073 of_node = gpiochip->parent->of_node;
2074 #ifdef CONFIG_OF_GPIO
2076 * If the gpiochip has an assigned OF node this takes precedence
2077 * FIXME: get rid of this and use gpiochip->parent->of_node
2080 if (gpiochip->of_node)
2081 of_node = gpiochip->of_node;
2084 * Specifying a default trigger is a terrible idea if DT or ACPI is
2085 * used to configure the interrupts, as you may end-up with
2086 * conflicting triggers. Tell the user, and reset to NONE.
2088 if (WARN(of_node && type != IRQ_TYPE_NONE,
2089 "%pOF: Ignoring %d default trigger\n", of_node, type))
2090 type = IRQ_TYPE_NONE;
2091 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2092 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2093 "Ignoring %d default trigger\n", type);
2094 type = IRQ_TYPE_NONE;
2097 gpiochip->irq.chip = irqchip;
2098 gpiochip->irq.handler = handler;
2099 gpiochip->irq.default_type = type;
2100 gpiochip->to_irq = gpiochip_to_irq;
2101 gpiochip->irq.lock_key = lock_key;
2102 gpiochip->irq.request_key = request_key;
2103 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2104 gpiochip->ngpio, first_irq,
2105 &gpiochip_domain_ops, gpiochip);
2106 if (!gpiochip->irq.domain) {
2107 gpiochip->irq.chip = NULL;
2111 gpiochip_set_irq_hooks(gpiochip);
2113 acpi_gpiochip_request_interrupts(gpiochip);
2117 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2119 #else /* CONFIG_GPIOLIB_IRQCHIP */
2121 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2122 struct lock_class_key *lock_key,
2123 struct lock_class_key *request_key)
2128 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2129 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2133 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2136 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2139 * gpiochip_generic_request() - request the gpio function for a pin
2140 * @chip: the gpiochip owning the GPIO
2141 * @offset: the offset of the GPIO to request for GPIO function
2143 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2145 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2147 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2150 * gpiochip_generic_free() - free the gpio function from a pin
2151 * @chip: the gpiochip to request the gpio function for
2152 * @offset: the offset of the GPIO to free from GPIO function
2154 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2156 pinctrl_gpio_free(chip->gpiodev->base + offset);
2158 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2161 * gpiochip_generic_config() - apply configuration for a pin
2162 * @chip: the gpiochip owning the GPIO
2163 * @offset: the offset of the GPIO to apply the configuration
2164 * @config: the configuration to be applied
2166 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2167 unsigned long config)
2169 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2171 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2173 #ifdef CONFIG_PINCTRL
2176 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2177 * @chip: the gpiochip to add the range for
2178 * @pctldev: the pin controller to map to
2179 * @gpio_offset: the start offset in the current gpio_chip number space
2180 * @pin_group: name of the pin group inside the pin controller
2182 * Calling this function directly from a DeviceTree-supported
2183 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2184 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2185 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2187 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2188 struct pinctrl_dev *pctldev,
2189 unsigned int gpio_offset, const char *pin_group)
2191 struct gpio_pin_range *pin_range;
2192 struct gpio_device *gdev = chip->gpiodev;
2195 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2197 chip_err(chip, "failed to allocate pin ranges\n");
2201 /* Use local offset as range ID */
2202 pin_range->range.id = gpio_offset;
2203 pin_range->range.gc = chip;
2204 pin_range->range.name = chip->label;
2205 pin_range->range.base = gdev->base + gpio_offset;
2206 pin_range->pctldev = pctldev;
2208 ret = pinctrl_get_group_pins(pctldev, pin_group,
2209 &pin_range->range.pins,
2210 &pin_range->range.npins);
2216 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2218 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2219 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2220 pinctrl_dev_get_devname(pctldev), pin_group);
2222 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2226 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2229 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2230 * @chip: the gpiochip to add the range for
2231 * @pinctl_name: the dev_name() of the pin controller to map to
2232 * @gpio_offset: the start offset in the current gpio_chip number space
2233 * @pin_offset: the start offset in the pin controller number space
2234 * @npins: the number of pins from the offset of each pin space (GPIO and
2235 * pin controller) to accumulate in this range
2238 * 0 on success, or a negative error-code on failure.
2240 * Calling this function directly from a DeviceTree-supported
2241 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2242 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2243 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2245 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2246 unsigned int gpio_offset, unsigned int pin_offset,
2249 struct gpio_pin_range *pin_range;
2250 struct gpio_device *gdev = chip->gpiodev;
2253 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2255 chip_err(chip, "failed to allocate pin ranges\n");
2259 /* Use local offset as range ID */
2260 pin_range->range.id = gpio_offset;
2261 pin_range->range.gc = chip;
2262 pin_range->range.name = chip->label;
2263 pin_range->range.base = gdev->base + gpio_offset;
2264 pin_range->range.pin_base = pin_offset;
2265 pin_range->range.npins = npins;
2266 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2268 if (IS_ERR(pin_range->pctldev)) {
2269 ret = PTR_ERR(pin_range->pctldev);
2270 chip_err(chip, "could not create pin range\n");
2274 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2275 gpio_offset, gpio_offset + npins - 1,
2277 pin_offset, pin_offset + npins - 1);
2279 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2283 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2286 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2287 * @chip: the chip to remove all the mappings for
2289 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2291 struct gpio_pin_range *pin_range, *tmp;
2292 struct gpio_device *gdev = chip->gpiodev;
2294 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2295 list_del(&pin_range->node);
2296 pinctrl_remove_gpio_range(pin_range->pctldev,
2301 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2303 #endif /* CONFIG_PINCTRL */
2305 /* These "optional" allocation calls help prevent drivers from stomping
2306 * on each other, and help provide better diagnostics in debugfs.
2307 * They're called even less than the "set direction" calls.
2309 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2311 struct gpio_chip *chip = desc->gdev->chip;
2313 unsigned long flags;
2317 label = kstrdup_const(label, GFP_KERNEL);
2322 spin_lock_irqsave(&gpio_lock, flags);
2324 /* NOTE: gpio_request() can be called in early boot,
2325 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2328 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2329 desc_set_label(desc, label ? : "?");
2337 if (chip->request) {
2338 /* chip->request may sleep */
2339 spin_unlock_irqrestore(&gpio_lock, flags);
2340 offset = gpio_chip_hwgpio(desc);
2341 if (gpiochip_line_is_valid(chip, offset))
2342 status = chip->request(chip, offset);
2345 spin_lock_irqsave(&gpio_lock, flags);
2348 desc_set_label(desc, NULL);
2350 clear_bit(FLAG_REQUESTED, &desc->flags);
2354 if (chip->get_direction) {
2355 /* chip->get_direction may sleep */
2356 spin_unlock_irqrestore(&gpio_lock, flags);
2357 gpiod_get_direction(desc);
2358 spin_lock_irqsave(&gpio_lock, flags);
2361 spin_unlock_irqrestore(&gpio_lock, flags);
2366 * This descriptor validation needs to be inserted verbatim into each
2367 * function taking a descriptor, so we need to use a preprocessor
2368 * macro to avoid endless duplication. If the desc is NULL it is an
2369 * optional GPIO and calls should just bail out.
2371 static int validate_desc(const struct gpio_desc *desc, const char *func)
2376 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2377 return PTR_ERR(desc);
2380 pr_warn("%s: invalid GPIO (no device)\n", func);
2383 if (!desc->gdev->chip) {
2384 dev_warn(&desc->gdev->dev,
2385 "%s: backing chip is gone\n", func);
2391 #define VALIDATE_DESC(desc) do { \
2392 int __valid = validate_desc(desc, __func__); \
2397 #define VALIDATE_DESC_VOID(desc) do { \
2398 int __valid = validate_desc(desc, __func__); \
2403 int gpiod_request(struct gpio_desc *desc, const char *label)
2405 int status = -EPROBE_DEFER;
2406 struct gpio_device *gdev;
2408 VALIDATE_DESC(desc);
2411 if (try_module_get(gdev->owner)) {
2412 status = gpiod_request_commit(desc, label);
2414 module_put(gdev->owner);
2416 get_device(&gdev->dev);
2420 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2425 static bool gpiod_free_commit(struct gpio_desc *desc)
2428 unsigned long flags;
2429 struct gpio_chip *chip;
2433 gpiod_unexport(desc);
2435 spin_lock_irqsave(&gpio_lock, flags);
2437 chip = desc->gdev->chip;
2438 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2440 spin_unlock_irqrestore(&gpio_lock, flags);
2441 might_sleep_if(chip->can_sleep);
2442 chip->free(chip, gpio_chip_hwgpio(desc));
2443 spin_lock_irqsave(&gpio_lock, flags);
2445 kfree_const(desc->label);
2446 desc_set_label(desc, NULL);
2447 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2448 clear_bit(FLAG_REQUESTED, &desc->flags);
2449 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2450 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2451 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2455 spin_unlock_irqrestore(&gpio_lock, flags);
2459 void gpiod_free(struct gpio_desc *desc)
2461 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2462 module_put(desc->gdev->owner);
2463 put_device(&desc->gdev->dev);
2465 WARN_ON(extra_checks);
2470 * gpiochip_is_requested - return string iff signal was requested
2471 * @chip: controller managing the signal
2472 * @offset: of signal within controller's 0..(ngpio - 1) range
2474 * Returns NULL if the GPIO is not currently requested, else a string.
2475 * The string returned is the label passed to gpio_request(); if none has been
2476 * passed it is a meaningless, non-NULL constant.
2478 * This function is for use by GPIO controller drivers. The label can
2479 * help with diagnostics, and knowing that the signal is used as a GPIO
2480 * can help avoid accidentally multiplexing it to another controller.
2482 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2484 struct gpio_desc *desc;
2486 if (offset >= chip->ngpio)
2489 desc = &chip->gpiodev->descs[offset];
2491 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2495 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2498 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2500 * @hwnum: hardware number of the GPIO for which to request the descriptor
2501 * @label: label for the GPIO
2502 * @flags: flags for this GPIO or 0 if default
2504 * Function allows GPIO chip drivers to request and use their own GPIO
2505 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2506 * function will not increase reference count of the GPIO chip module. This
2507 * allows the GPIO chip module to be unloaded as needed (we assume that the
2508 * GPIO chip driver handles freeing the GPIOs it has requested).
2511 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2514 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2516 enum gpiod_flags flags)
2518 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2522 chip_err(chip, "failed to get GPIO descriptor\n");
2526 err = gpiod_request_commit(desc, label);
2528 return ERR_PTR(err);
2530 err = gpiod_configure_flags(desc, label, 0, flags);
2532 chip_err(chip, "setup of own GPIO %s failed\n", label);
2533 gpiod_free_commit(desc);
2534 return ERR_PTR(err);
2539 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2542 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2543 * @desc: GPIO descriptor to free
2545 * Function frees the given GPIO requested previously with
2546 * gpiochip_request_own_desc().
2548 void gpiochip_free_own_desc(struct gpio_desc *desc)
2551 gpiod_free_commit(desc);
2553 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2556 * Drivers MUST set GPIO direction before making get/set calls. In
2557 * some cases this is done in early boot, before IRQs are enabled.
2559 * As a rule these aren't called more than once (except for drivers
2560 * using the open-drain emulation idiom) so these are natural places
2561 * to accumulate extra debugging checks. Note that we can't (yet)
2562 * rely on gpio_request() having been called beforehand.
2565 static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
2566 enum pin_config_param mode)
2568 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2570 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2574 * gpiod_direction_input - set the GPIO direction to input
2575 * @desc: GPIO to set to input
2577 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2578 * be called safely on it.
2580 * Return 0 in case of success, else an error code.
2582 int gpiod_direction_input(struct gpio_desc *desc)
2584 struct gpio_chip *chip;
2587 VALIDATE_DESC(desc);
2588 chip = desc->gdev->chip;
2591 * It is legal to have no .get() and .direction_input() specified if
2592 * the chip is output-only, but you can't specify .direction_input()
2593 * and not support the .get() operation, that doesn't make sense.
2595 if (!chip->get && chip->direction_input) {
2597 "%s: missing get() but have direction_input()\n",
2603 * If we have a .direction_input() callback, things are simple,
2604 * just call it. Else we are some input-only chip so try to check the
2605 * direction (if .get_direction() is supported) else we silently
2606 * assume we are in input mode after this.
2608 if (chip->direction_input) {
2609 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2610 } else if (chip->get_direction &&
2611 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2613 "%s: missing direction_input() operation and line is output\n",
2618 clear_bit(FLAG_IS_OUT, &desc->flags);
2620 if (test_bit(FLAG_PULL_UP, &desc->flags))
2621 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2622 PIN_CONFIG_BIAS_PULL_UP);
2623 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2624 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2625 PIN_CONFIG_BIAS_PULL_DOWN);
2627 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2631 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2633 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2635 struct gpio_chip *gc = desc->gdev->chip;
2640 * It's OK not to specify .direction_output() if the gpiochip is
2641 * output-only, but if there is then not even a .set() operation it
2642 * is pretty tricky to drive the output line.
2644 if (!gc->set && !gc->direction_output) {
2646 "%s: missing set() and direction_output() operations\n",
2651 if (gc->direction_output) {
2652 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2654 /* Check that we are in output mode if we can */
2655 if (gc->get_direction &&
2656 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2658 "%s: missing direction_output() operation\n",
2663 * If we can't actively set the direction, we are some
2664 * output-only chip, so just drive the output as desired.
2666 gc->set(gc, gpio_chip_hwgpio(desc), val);
2670 set_bit(FLAG_IS_OUT, &desc->flags);
2671 trace_gpio_value(desc_to_gpio(desc), 0, val);
2672 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2677 * gpiod_direction_output_raw - set the GPIO direction to output
2678 * @desc: GPIO to set to output
2679 * @value: initial output value of the GPIO
2681 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2682 * be called safely on it. The initial value of the output must be specified
2683 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2685 * Return 0 in case of success, else an error code.
2687 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2689 VALIDATE_DESC(desc);
2690 return gpiod_direction_output_raw_commit(desc, value);
2692 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2695 * gpiod_direction_output - set the GPIO direction to output
2696 * @desc: GPIO to set to output
2697 * @value: initial output value of the GPIO
2699 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2700 * be called safely on it. The initial value of the output must be specified
2701 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2704 * Return 0 in case of success, else an error code.
2706 int gpiod_direction_output(struct gpio_desc *desc, int value)
2708 struct gpio_chip *gc;
2711 VALIDATE_DESC(desc);
2712 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2717 /* GPIOs used for enabled IRQs shall not be set as output */
2718 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2719 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2721 "%s: tried to set a GPIO tied to an IRQ as output\n",
2726 gc = desc->gdev->chip;
2727 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2728 /* First see if we can enable open drain in hardware */
2729 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2730 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2732 goto set_output_value;
2733 /* Emulate open drain by not actively driving the line high */
2735 return gpiod_direction_input(desc);
2737 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2738 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2739 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2741 goto set_output_value;
2742 /* Emulate open source by not actively driving the line low */
2744 return gpiod_direction_input(desc);
2746 gpio_set_config(gc, gpio_chip_hwgpio(desc),
2747 PIN_CONFIG_DRIVE_PUSH_PULL);
2751 return gpiod_direction_output_raw_commit(desc, value);
2753 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2756 * gpiod_set_debounce - sets @debounce time for a GPIO
2757 * @desc: descriptor of the GPIO for which to set debounce time
2758 * @debounce: debounce time in microseconds
2761 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2764 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2766 struct gpio_chip *chip;
2767 unsigned long config;
2769 VALIDATE_DESC(desc);
2770 chip = desc->gdev->chip;
2771 if (!chip->set || !chip->set_config) {
2773 "%s: missing set() or set_config() operations\n",
2778 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2779 return gpio_set_config(chip, gpio_chip_hwgpio(desc), config);
2781 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2784 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2785 * @desc: descriptor of the GPIO for which to configure persistence
2786 * @transitory: True to lose state on suspend or reset, false for persistence
2789 * 0 on success, otherwise a negative error code.
2791 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2793 struct gpio_chip *chip;
2794 unsigned long packed;
2798 VALIDATE_DESC(desc);
2800 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2801 * persistence state.
2804 set_bit(FLAG_TRANSITORY, &desc->flags);
2806 clear_bit(FLAG_TRANSITORY, &desc->flags);
2808 /* If the driver supports it, set the persistence state now */
2809 chip = desc->gdev->chip;
2810 if (!chip->set_config)
2813 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2815 gpio = gpio_chip_hwgpio(desc);
2816 rc = gpio_set_config(chip, gpio, packed);
2817 if (rc == -ENOTSUPP) {
2818 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2825 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2828 * gpiod_is_active_low - test whether a GPIO is active-low or not
2829 * @desc: the gpio descriptor to test
2831 * Returns 1 if the GPIO is active-low, 0 otherwise.
2833 int gpiod_is_active_low(const struct gpio_desc *desc)
2835 VALIDATE_DESC(desc);
2836 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2838 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2840 /* I/O calls are only valid after configuration completed; the relevant
2841 * "is this a valid GPIO" error checks should already have been done.
2843 * "Get" operations are often inlinable as reading a pin value register,
2844 * and masking the relevant bit in that register.
2846 * When "set" operations are inlinable, they involve writing that mask to
2847 * one register to set a low value, or a different register to set it high.
2848 * Otherwise locking is needed, so there may be little value to inlining.
2850 *------------------------------------------------------------------------
2852 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2853 * have requested the GPIO. That can include implicit requesting by
2854 * a direction setting call. Marking a gpio as requested locks its chip
2855 * in memory, guaranteeing that these table lookups need no more locking
2856 * and that gpiochip_remove() will fail.
2858 * REVISIT when debugging, consider adding some instrumentation to ensure
2859 * that the GPIO was actually requested.
2862 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2864 struct gpio_chip *chip;
2868 chip = desc->gdev->chip;
2869 offset = gpio_chip_hwgpio(desc);
2870 value = chip->get ? chip->get(chip, offset) : -EIO;
2871 value = value < 0 ? value : !!value;
2872 trace_gpio_value(desc_to_gpio(desc), 1, value);
2876 static int gpio_chip_get_multiple(struct gpio_chip *chip,
2877 unsigned long *mask, unsigned long *bits)
2879 if (chip->get_multiple) {
2880 return chip->get_multiple(chip, mask, bits);
2881 } else if (chip->get) {
2884 for_each_set_bit(i, mask, chip->ngpio) {
2885 value = chip->get(chip, i);
2888 __assign_bit(i, bits, value);
2895 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2896 unsigned int array_size,
2897 struct gpio_desc **desc_array,
2898 struct gpio_array *array_info,
2899 unsigned long *value_bitmap)
2904 * Validate array_info against desc_array and its size.
2905 * It should immediately follow desc_array if both
2906 * have been obtained from the same gpiod_get_array() call.
2908 if (array_info && array_info->desc == desc_array &&
2909 array_size <= array_info->size &&
2910 (void *)array_info == desc_array + array_info->size) {
2912 WARN_ON(array_info->chip->can_sleep);
2914 err = gpio_chip_get_multiple(array_info->chip,
2915 array_info->get_mask,
2920 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2921 bitmap_xor(value_bitmap, value_bitmap,
2922 array_info->invert_mask, array_size);
2924 if (bitmap_full(array_info->get_mask, array_size))
2927 i = find_first_zero_bit(array_info->get_mask, array_size);
2932 while (i < array_size) {
2933 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2934 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2935 unsigned long *mask, *bits;
2938 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2941 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2943 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2948 bits = mask + BITS_TO_LONGS(chip->ngpio);
2949 bitmap_zero(mask, chip->ngpio);
2952 WARN_ON(chip->can_sleep);
2954 /* collect all inputs belonging to the same chip */
2957 const struct gpio_desc *desc = desc_array[i];
2958 int hwgpio = gpio_chip_hwgpio(desc);
2960 __set_bit(hwgpio, mask);
2964 i = find_next_zero_bit(array_info->get_mask,
2966 } while ((i < array_size) &&
2967 (desc_array[i]->gdev->chip == chip));
2969 ret = gpio_chip_get_multiple(chip, mask, bits);
2971 if (mask != fastpath)
2976 for (j = first; j < i; ) {
2977 const struct gpio_desc *desc = desc_array[j];
2978 int hwgpio = gpio_chip_hwgpio(desc);
2979 int value = test_bit(hwgpio, bits);
2981 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2983 __assign_bit(j, value_bitmap, value);
2984 trace_gpio_value(desc_to_gpio(desc), 1, value);
2988 j = find_next_zero_bit(array_info->get_mask, i,
2992 if (mask != fastpath)
2999 * gpiod_get_raw_value() - return a gpio's raw value
3000 * @desc: gpio whose value will be returned
3002 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3003 * its ACTIVE_LOW status, or negative errno on failure.
3005 * This function should be called from contexts where we cannot sleep, and will
3006 * complain if the GPIO chip functions potentially sleep.
3008 int gpiod_get_raw_value(const struct gpio_desc *desc)
3010 VALIDATE_DESC(desc);
3011 /* Should be using gpio_get_value_cansleep() */
3012 WARN_ON(desc->gdev->chip->can_sleep);
3013 return gpiod_get_raw_value_commit(desc);
3015 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3018 * gpiod_get_value() - return a gpio's value
3019 * @desc: gpio whose value will be returned
3021 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3022 * account, or negative errno on failure.
3024 * This function should be called from contexts where we cannot sleep, and will
3025 * complain if the GPIO chip functions potentially sleep.
3027 int gpiod_get_value(const struct gpio_desc *desc)
3031 VALIDATE_DESC(desc);
3032 /* Should be using gpio_get_value_cansleep() */
3033 WARN_ON(desc->gdev->chip->can_sleep);
3035 value = gpiod_get_raw_value_commit(desc);
3039 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3044 EXPORT_SYMBOL_GPL(gpiod_get_value);
3047 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3048 * @array_size: number of elements in the descriptor array / value bitmap
3049 * @desc_array: array of GPIO descriptors whose values will be read
3050 * @array_info: information on applicability of fast bitmap processing path
3051 * @value_bitmap: bitmap to store the read values
3053 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3054 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3055 * else an error code.
3057 * This function should be called from contexts where we cannot sleep,
3058 * and it will complain if the GPIO chip functions potentially sleep.
3060 int gpiod_get_raw_array_value(unsigned int array_size,
3061 struct gpio_desc **desc_array,
3062 struct gpio_array *array_info,
3063 unsigned long *value_bitmap)
3067 return gpiod_get_array_value_complex(true, false, array_size,
3068 desc_array, array_info,
3071 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3074 * gpiod_get_array_value() - read values from an array of GPIOs
3075 * @array_size: number of elements in the descriptor array / value bitmap
3076 * @desc_array: array of GPIO descriptors whose values will be read
3077 * @array_info: information on applicability of fast bitmap processing path
3078 * @value_bitmap: bitmap to store the read values
3080 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3081 * into account. Return 0 in case of success, else an error code.
3083 * This function should be called from contexts where we cannot sleep,
3084 * and it will complain if the GPIO chip functions potentially sleep.
3086 int gpiod_get_array_value(unsigned int array_size,
3087 struct gpio_desc **desc_array,
3088 struct gpio_array *array_info,
3089 unsigned long *value_bitmap)
3093 return gpiod_get_array_value_complex(false, false, array_size,
3094 desc_array, array_info,
3097 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3100 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3101 * @desc: gpio descriptor whose state need to be set.
3102 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3104 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3107 struct gpio_chip *chip = desc->gdev->chip;
3108 int offset = gpio_chip_hwgpio(desc);
3111 err = chip->direction_input(chip, offset);
3113 clear_bit(FLAG_IS_OUT, &desc->flags);
3115 err = chip->direction_output(chip, offset, 0);
3117 set_bit(FLAG_IS_OUT, &desc->flags);
3119 trace_gpio_direction(desc_to_gpio(desc), value, err);
3122 "%s: Error in set_value for open drain err %d\n",
3127 * _gpio_set_open_source_value() - Set the open source gpio's value.
3128 * @desc: gpio descriptor whose state need to be set.
3129 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3131 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3134 struct gpio_chip *chip = desc->gdev->chip;
3135 int offset = gpio_chip_hwgpio(desc);
3138 err = chip->direction_output(chip, offset, 1);
3140 set_bit(FLAG_IS_OUT, &desc->flags);
3142 err = chip->direction_input(chip, offset);
3144 clear_bit(FLAG_IS_OUT, &desc->flags);
3146 trace_gpio_direction(desc_to_gpio(desc), !value, err);
3149 "%s: Error in set_value for open source err %d\n",
3153 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3155 struct gpio_chip *chip;
3157 chip = desc->gdev->chip;
3158 trace_gpio_value(desc_to_gpio(desc), 0, value);
3159 chip->set(chip, gpio_chip_hwgpio(desc), value);
3163 * set multiple outputs on the same chip;
3164 * use the chip's set_multiple function if available;
3165 * otherwise set the outputs sequentially;
3166 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3167 * defines which outputs are to be changed
3168 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3169 * defines the values the outputs specified by mask are to be set to
3171 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3172 unsigned long *mask, unsigned long *bits)
3174 if (chip->set_multiple) {
3175 chip->set_multiple(chip, mask, bits);
3179 /* set outputs if the corresponding mask bit is set */
3180 for_each_set_bit(i, mask, chip->ngpio)
3181 chip->set(chip, i, test_bit(i, bits));
3185 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3186 unsigned int array_size,
3187 struct gpio_desc **desc_array,
3188 struct gpio_array *array_info,
3189 unsigned long *value_bitmap)
3194 * Validate array_info against desc_array and its size.
3195 * It should immediately follow desc_array if both
3196 * have been obtained from the same gpiod_get_array() call.
3198 if (array_info && array_info->desc == desc_array &&
3199 array_size <= array_info->size &&
3200 (void *)array_info == desc_array + array_info->size) {
3202 WARN_ON(array_info->chip->can_sleep);
3204 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3205 bitmap_xor(value_bitmap, value_bitmap,
3206 array_info->invert_mask, array_size);
3208 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3211 if (bitmap_full(array_info->set_mask, array_size))
3214 i = find_first_zero_bit(array_info->set_mask, array_size);
3219 while (i < array_size) {
3220 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3221 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3222 unsigned long *mask, *bits;
3225 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3228 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3230 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3235 bits = mask + BITS_TO_LONGS(chip->ngpio);
3236 bitmap_zero(mask, chip->ngpio);
3239 WARN_ON(chip->can_sleep);
3242 struct gpio_desc *desc = desc_array[i];
3243 int hwgpio = gpio_chip_hwgpio(desc);
3244 int value = test_bit(i, value_bitmap);
3247 * Pins applicable for fast input but not for
3248 * fast output processing may have been already
3249 * inverted inside the fast path, skip them.
3251 if (!raw && !(array_info &&
3252 test_bit(i, array_info->invert_mask)) &&
3253 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3255 trace_gpio_value(desc_to_gpio(desc), 0, value);
3257 * collect all normal outputs belonging to the same chip
3258 * open drain and open source outputs are set individually
3260 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3261 gpio_set_open_drain_value_commit(desc, value);
3262 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3263 gpio_set_open_source_value_commit(desc, value);
3265 __set_bit(hwgpio, mask);
3267 __set_bit(hwgpio, bits);
3269 __clear_bit(hwgpio, bits);
3275 i = find_next_zero_bit(array_info->set_mask,
3277 } while ((i < array_size) &&
3278 (desc_array[i]->gdev->chip == chip));
3279 /* push collected bits to outputs */
3281 gpio_chip_set_multiple(chip, mask, bits);
3283 if (mask != fastpath)
3290 * gpiod_set_raw_value() - assign a gpio's raw value
3291 * @desc: gpio whose value will be assigned
3292 * @value: value to assign
3294 * Set the raw value of the GPIO, i.e. the value of its physical line without
3295 * regard for its ACTIVE_LOW status.
3297 * This function should be called from contexts where we cannot sleep, and will
3298 * complain if the GPIO chip functions potentially sleep.
3300 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3302 VALIDATE_DESC_VOID(desc);
3303 /* Should be using gpiod_set_value_cansleep() */
3304 WARN_ON(desc->gdev->chip->can_sleep);
3305 gpiod_set_raw_value_commit(desc, value);
3307 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3310 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3311 * @desc: the descriptor to set the value on
3312 * @value: value to set
3314 * This sets the value of a GPIO line backing a descriptor, applying
3315 * different semantic quirks like active low and open drain/source
3318 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3320 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3322 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3323 gpio_set_open_drain_value_commit(desc, value);
3324 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3325 gpio_set_open_source_value_commit(desc, value);
3327 gpiod_set_raw_value_commit(desc, value);
3331 * gpiod_set_value() - assign a gpio's value
3332 * @desc: gpio whose value will be assigned
3333 * @value: value to assign
3335 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3336 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3338 * This function should be called from contexts where we cannot sleep, and will
3339 * complain if the GPIO chip functions potentially sleep.
3341 void gpiod_set_value(struct gpio_desc *desc, int value)
3343 VALIDATE_DESC_VOID(desc);
3344 WARN_ON(desc->gdev->chip->can_sleep);
3345 gpiod_set_value_nocheck(desc, value);
3347 EXPORT_SYMBOL_GPL(gpiod_set_value);
3350 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3351 * @array_size: number of elements in the descriptor array / value bitmap
3352 * @desc_array: array of GPIO descriptors whose values will be assigned
3353 * @array_info: information on applicability of fast bitmap processing path
3354 * @value_bitmap: bitmap of values to assign
3356 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3357 * without regard for their ACTIVE_LOW status.
3359 * This function should be called from contexts where we cannot sleep, and will
3360 * complain if the GPIO chip functions potentially sleep.
3362 int gpiod_set_raw_array_value(unsigned int array_size,
3363 struct gpio_desc **desc_array,
3364 struct gpio_array *array_info,
3365 unsigned long *value_bitmap)
3369 return gpiod_set_array_value_complex(true, false, array_size,
3370 desc_array, array_info, value_bitmap);
3372 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3375 * gpiod_set_array_value() - assign values to an array of GPIOs
3376 * @array_size: number of elements in the descriptor array / value bitmap
3377 * @desc_array: array of GPIO descriptors whose values will be assigned
3378 * @array_info: information on applicability of fast bitmap processing path
3379 * @value_bitmap: bitmap of values to assign
3381 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3384 * This function should be called from contexts where we cannot sleep, and will
3385 * complain if the GPIO chip functions potentially sleep.
3387 int gpiod_set_array_value(unsigned int array_size,
3388 struct gpio_desc **desc_array,
3389 struct gpio_array *array_info,
3390 unsigned long *value_bitmap)
3394 return gpiod_set_array_value_complex(false, false, array_size,
3395 desc_array, array_info,
3398 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3401 * gpiod_cansleep() - report whether gpio value access may sleep
3402 * @desc: gpio to check
3405 int gpiod_cansleep(const struct gpio_desc *desc)
3407 VALIDATE_DESC(desc);
3408 return desc->gdev->chip->can_sleep;
3410 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3413 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3414 * @desc: gpio to set the consumer name on
3415 * @name: the new consumer name
3417 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3419 VALIDATE_DESC(desc);
3421 name = kstrdup_const(name, GFP_KERNEL);
3426 kfree_const(desc->label);
3427 desc_set_label(desc, name);
3431 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3434 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3435 * @desc: gpio whose IRQ will be returned (already requested)
3437 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3440 int gpiod_to_irq(const struct gpio_desc *desc)
3442 struct gpio_chip *chip;
3446 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3447 * requires this function to not return zero on an invalid descriptor
3448 * but rather a negative error number.
3450 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3453 chip = desc->gdev->chip;
3454 offset = gpio_chip_hwgpio(desc);
3456 int retirq = chip->to_irq(chip, offset);
3458 /* Zero means NO_IRQ */
3466 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3469 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3470 * @chip: the chip the GPIO to lock belongs to
3471 * @offset: the offset of the GPIO to lock as IRQ
3473 * This is used directly by GPIO drivers that want to lock down
3474 * a certain GPIO line to be used for IRQs.
3476 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3478 struct gpio_desc *desc;
3480 desc = gpiochip_get_desc(chip, offset);
3482 return PTR_ERR(desc);
3485 * If it's fast: flush the direction setting if something changed
3488 if (!chip->can_sleep && chip->get_direction) {
3489 int dir = gpiod_get_direction(desc);
3492 chip_err(chip, "%s: cannot get GPIO direction\n",
3498 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3500 "%s: tried to flag a GPIO set as output for IRQ\n",
3505 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3506 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3509 * If the consumer has not set up a label (such as when the
3510 * IRQ is referenced from .to_irq()) we set up a label here
3511 * so it is clear this is used as an interrupt.
3514 desc_set_label(desc, "interrupt");
3518 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3521 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3522 * @chip: the chip the GPIO to lock belongs to
3523 * @offset: the offset of the GPIO to lock as IRQ
3525 * This is used directly by GPIO drivers that want to indicate
3526 * that a certain GPIO is no longer used exclusively for IRQ.
3528 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3530 struct gpio_desc *desc;
3532 desc = gpiochip_get_desc(chip, offset);
3536 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3537 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3539 /* If we only had this marking, erase it */
3540 if (desc->label && !strcmp(desc->label, "interrupt"))
3541 desc_set_label(desc, NULL);
3543 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3545 void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3547 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3549 if (!IS_ERR(desc) &&
3550 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3551 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3553 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3555 void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3557 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3559 if (!IS_ERR(desc) &&
3560 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3561 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags));
3562 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3565 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3567 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3569 if (offset >= chip->ngpio)
3572 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3574 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3576 int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset)
3580 if (!try_module_get(chip->gpiodev->owner))
3583 ret = gpiochip_lock_as_irq(chip, offset);
3585 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset);
3586 module_put(chip->gpiodev->owner);
3591 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3593 void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset)
3595 gpiochip_unlock_as_irq(chip, offset);
3596 module_put(chip->gpiodev->owner);
3598 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3600 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3602 if (offset >= chip->ngpio)
3605 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3607 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3609 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3611 if (offset >= chip->ngpio)
3614 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3616 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3618 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3620 if (offset >= chip->ngpio)
3623 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3625 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3628 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3629 * @desc: gpio whose value will be returned
3631 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3632 * its ACTIVE_LOW status, or negative errno on failure.
3634 * This function is to be called from contexts that can sleep.
3636 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3638 might_sleep_if(extra_checks);
3639 VALIDATE_DESC(desc);
3640 return gpiod_get_raw_value_commit(desc);
3642 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3645 * gpiod_get_value_cansleep() - return a gpio's value
3646 * @desc: gpio whose value will be returned
3648 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3649 * account, or negative errno on failure.
3651 * This function is to be called from contexts that can sleep.
3653 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3657 might_sleep_if(extra_checks);
3658 VALIDATE_DESC(desc);
3659 value = gpiod_get_raw_value_commit(desc);
3663 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3668 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3671 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3672 * @array_size: number of elements in the descriptor array / value bitmap
3673 * @desc_array: array of GPIO descriptors whose values will be read
3674 * @array_info: information on applicability of fast bitmap processing path
3675 * @value_bitmap: bitmap to store the read values
3677 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3678 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3679 * else an error code.
3681 * This function is to be called from contexts that can sleep.
3683 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3684 struct gpio_desc **desc_array,
3685 struct gpio_array *array_info,
3686 unsigned long *value_bitmap)
3688 might_sleep_if(extra_checks);
3691 return gpiod_get_array_value_complex(true, true, array_size,
3692 desc_array, array_info,
3695 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3698 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3699 * @array_size: number of elements in the descriptor array / value bitmap
3700 * @desc_array: array of GPIO descriptors whose values will be read
3701 * @array_info: information on applicability of fast bitmap processing path
3702 * @value_bitmap: bitmap to store the read values
3704 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3705 * into account. Return 0 in case of success, else an error code.
3707 * This function is to be called from contexts that can sleep.
3709 int gpiod_get_array_value_cansleep(unsigned int array_size,
3710 struct gpio_desc **desc_array,
3711 struct gpio_array *array_info,
3712 unsigned long *value_bitmap)
3714 might_sleep_if(extra_checks);
3717 return gpiod_get_array_value_complex(false, true, array_size,
3718 desc_array, array_info,
3721 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3724 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3725 * @desc: gpio whose value will be assigned
3726 * @value: value to assign
3728 * Set the raw value of the GPIO, i.e. the value of its physical line without
3729 * regard for its ACTIVE_LOW status.
3731 * This function is to be called from contexts that can sleep.
3733 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3735 might_sleep_if(extra_checks);
3736 VALIDATE_DESC_VOID(desc);
3737 gpiod_set_raw_value_commit(desc, value);
3739 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3742 * gpiod_set_value_cansleep() - assign a gpio's value
3743 * @desc: gpio whose value will be assigned
3744 * @value: value to assign
3746 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3749 * This function is to be called from contexts that can sleep.
3751 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3753 might_sleep_if(extra_checks);
3754 VALIDATE_DESC_VOID(desc);
3755 gpiod_set_value_nocheck(desc, value);
3757 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3760 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3761 * @array_size: number of elements in the descriptor array / value bitmap
3762 * @desc_array: array of GPIO descriptors whose values will be assigned
3763 * @array_info: information on applicability of fast bitmap processing path
3764 * @value_bitmap: bitmap of values to assign
3766 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3767 * without regard for their ACTIVE_LOW status.
3769 * This function is to be called from contexts that can sleep.
3771 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3772 struct gpio_desc **desc_array,
3773 struct gpio_array *array_info,
3774 unsigned long *value_bitmap)
3776 might_sleep_if(extra_checks);
3779 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3780 array_info, value_bitmap);
3782 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3785 * gpiod_add_lookup_tables() - register GPIO device consumers
3786 * @tables: list of tables of consumers to register
3787 * @n: number of tables in the list
3789 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3793 mutex_lock(&gpio_lookup_lock);
3795 for (i = 0; i < n; i++)
3796 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3798 mutex_unlock(&gpio_lookup_lock);
3802 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3803 * @array_size: number of elements in the descriptor array / value bitmap
3804 * @desc_array: array of GPIO descriptors whose values will be assigned
3805 * @array_info: information on applicability of fast bitmap processing path
3806 * @value_bitmap: bitmap of values to assign
3808 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3811 * This function is to be called from contexts that can sleep.
3813 int gpiod_set_array_value_cansleep(unsigned int array_size,
3814 struct gpio_desc **desc_array,
3815 struct gpio_array *array_info,
3816 unsigned long *value_bitmap)
3818 might_sleep_if(extra_checks);
3821 return gpiod_set_array_value_complex(false, true, array_size,
3822 desc_array, array_info,
3825 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3828 * gpiod_add_lookup_table() - register GPIO device consumers
3829 * @table: table of consumers to register
3831 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3833 mutex_lock(&gpio_lookup_lock);
3835 list_add_tail(&table->list, &gpio_lookup_list);
3837 mutex_unlock(&gpio_lookup_lock);
3839 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3842 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3843 * @table: table of consumers to unregister
3845 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3847 mutex_lock(&gpio_lookup_lock);
3849 list_del(&table->list);
3851 mutex_unlock(&gpio_lookup_lock);
3853 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3856 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3857 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3859 void gpiod_add_hogs(struct gpiod_hog *hogs)
3861 struct gpio_chip *chip;
3862 struct gpiod_hog *hog;
3864 mutex_lock(&gpio_machine_hogs_mutex);
3866 for (hog = &hogs[0]; hog->chip_label; hog++) {
3867 list_add_tail(&hog->list, &gpio_machine_hogs);
3870 * The chip may have been registered earlier, so check if it
3871 * exists and, if so, try to hog the line now.
3873 chip = find_chip_by_name(hog->chip_label);
3875 gpiochip_machine_hog(chip, hog);
3878 mutex_unlock(&gpio_machine_hogs_mutex);
3880 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3882 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3884 const char *dev_id = dev ? dev_name(dev) : NULL;
3885 struct gpiod_lookup_table *table;
3887 mutex_lock(&gpio_lookup_lock);
3889 list_for_each_entry(table, &gpio_lookup_list, list) {
3890 if (table->dev_id && dev_id) {
3892 * Valid strings on both ends, must be identical to have
3895 if (!strcmp(table->dev_id, dev_id))
3899 * One of the pointers is NULL, so both must be to have
3902 if (dev_id == table->dev_id)
3909 mutex_unlock(&gpio_lookup_lock);
3913 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3915 enum gpio_lookup_flags *flags)
3917 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3918 struct gpiod_lookup_table *table;
3919 struct gpiod_lookup *p;
3921 table = gpiod_find_lookup_table(dev);
3925 for (p = &table->table[0]; p->chip_label; p++) {
3926 struct gpio_chip *chip;
3928 /* idx must always match exactly */
3932 /* If the lookup entry has a con_id, require exact match */
3933 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3936 chip = find_chip_by_name(p->chip_label);
3940 * As the lookup table indicates a chip with
3941 * p->chip_label should exist, assume it may
3942 * still appear later and let the interested
3943 * consumer be probed again or let the Deferred
3944 * Probe infrastructure handle the error.
3946 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3948 return ERR_PTR(-EPROBE_DEFER);
3951 if (chip->ngpio <= p->chip_hwnum) {
3953 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3954 idx, chip->ngpio, chip->label);
3955 return ERR_PTR(-EINVAL);
3958 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3967 static int dt_gpio_count(struct device *dev, const char *con_id)
3973 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3975 snprintf(propname, sizeof(propname), "%s-%s",
3976 con_id, gpio_suffixes[i]);
3978 snprintf(propname, sizeof(propname), "%s",
3981 ret = of_gpio_named_count(dev->of_node, propname);
3985 return ret ? ret : -ENOENT;
3988 static int platform_gpio_count(struct device *dev, const char *con_id)
3990 struct gpiod_lookup_table *table;
3991 struct gpiod_lookup *p;
3992 unsigned int count = 0;
3994 table = gpiod_find_lookup_table(dev);
3998 for (p = &table->table[0]; p->chip_label; p++) {
3999 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4000 (!con_id && !p->con_id))
4010 * gpiod_count - return the number of GPIOs associated with a device / function
4011 * or -ENOENT if no GPIO has been assigned to the requested function
4012 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4013 * @con_id: function within the GPIO consumer
4015 int gpiod_count(struct device *dev, const char *con_id)
4017 int count = -ENOENT;
4019 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
4020 count = dt_gpio_count(dev, con_id);
4021 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
4022 count = acpi_gpio_count(dev, con_id);
4025 count = platform_gpio_count(dev, con_id);
4029 EXPORT_SYMBOL_GPL(gpiod_count);
4032 * gpiod_get - obtain a GPIO for a given GPIO function
4033 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4034 * @con_id: function within the GPIO consumer
4035 * @flags: optional GPIO initialization flags
4037 * Return the GPIO descriptor corresponding to the function con_id of device
4038 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4039 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4041 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4042 enum gpiod_flags flags)
4044 return gpiod_get_index(dev, con_id, 0, flags);
4046 EXPORT_SYMBOL_GPL(gpiod_get);
4049 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4050 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4051 * @con_id: function within the GPIO consumer
4052 * @flags: optional GPIO initialization flags
4054 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4055 * the requested function it will return NULL. This is convenient for drivers
4056 * that need to handle optional GPIOs.
4058 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4060 enum gpiod_flags flags)
4062 return gpiod_get_index_optional(dev, con_id, 0, flags);
4064 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4068 * gpiod_configure_flags - helper function to configure a given GPIO
4069 * @desc: gpio whose value will be assigned
4070 * @con_id: function within the GPIO consumer
4071 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4073 * @dflags: gpiod_flags - optional GPIO initialization flags
4075 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4076 * requested function and/or index, or another IS_ERR() code if an error
4077 * occurred while trying to acquire the GPIO.
4079 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4080 unsigned long lflags, enum gpiod_flags dflags)
4084 if (lflags & GPIO_ACTIVE_LOW)
4085 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4087 if (lflags & GPIO_OPEN_DRAIN)
4088 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4089 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4091 * This enforces open drain mode from the consumer side.
4092 * This is necessary for some busses like I2C, but the lookup
4093 * should *REALLY* have specified them as open drain in the
4094 * first place, so print a little warning here.
4096 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4098 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4101 if (lflags & GPIO_OPEN_SOURCE)
4102 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4104 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
4106 "both pull-up and pull-down enabled, invalid configuration\n");
4110 if (lflags & GPIO_PULL_UP)
4111 set_bit(FLAG_PULL_UP, &desc->flags);
4112 else if (lflags & GPIO_PULL_DOWN)
4113 set_bit(FLAG_PULL_DOWN, &desc->flags);
4115 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4119 /* No particular flag request, return here... */
4120 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4121 pr_debug("no flags found for %s\n", con_id);
4126 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4127 status = gpiod_direction_output(desc,
4128 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4130 status = gpiod_direction_input(desc);
4136 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4137 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4138 * @con_id: function within the GPIO consumer
4139 * @idx: index of the GPIO to obtain in the consumer
4140 * @flags: optional GPIO initialization flags
4142 * This variant of gpiod_get() allows to access GPIOs other than the first
4143 * defined one for functions that define several GPIOs.
4145 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4146 * requested function and/or index, or another IS_ERR() code if an error
4147 * occurred while trying to acquire the GPIO.
4149 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4152 enum gpiod_flags flags)
4154 struct gpio_desc *desc = NULL;
4156 enum gpio_lookup_flags lookupflags = 0;
4157 /* Maybe we have a device name, maybe not */
4158 const char *devname = dev ? dev_name(dev) : "?";
4160 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4163 /* Using device tree? */
4164 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4165 dev_dbg(dev, "using device tree for GPIO lookup\n");
4166 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4167 } else if (ACPI_COMPANION(dev)) {
4168 dev_dbg(dev, "using ACPI for GPIO lookup\n");
4169 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4174 * Either we are not using DT or ACPI, or their lookup did not return
4175 * a result. In that case, use platform lookup as a fallback.
4177 if (!desc || desc == ERR_PTR(-ENOENT)) {
4178 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4179 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4183 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4188 * If a connection label was passed use that, else attempt to use
4189 * the device name as label
4191 status = gpiod_request(desc, con_id ? con_id : devname);
4193 if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4195 * This happens when there are several consumers for
4196 * the same GPIO line: we just return here without
4197 * further initialization. It is a bit if a hack.
4198 * This is necessary to support fixed regulators.
4200 * FIXME: Make this more sane and safe.
4202 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4203 con_id ? con_id : devname);
4206 return ERR_PTR(status);
4210 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4212 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4214 return ERR_PTR(status);
4219 EXPORT_SYMBOL_GPL(gpiod_get_index);
4222 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
4223 * @node: handle of the OF node
4224 * @propname: name of the DT property representing the GPIO
4225 * @index: index of the GPIO to obtain for the consumer
4226 * @dflags: GPIO initialization flags
4227 * @label: label to attach to the requested GPIO
4230 * On successful request the GPIO pin is configured in accordance with
4231 * provided @dflags. If the node does not have the requested GPIO
4232 * property, NULL is returned.
4234 * In case of error an ERR_PTR() is returned.
4236 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
4237 const char *propname, int index,
4238 enum gpiod_flags dflags,
4241 struct gpio_desc *desc;
4242 unsigned long lflags = 0;
4243 enum of_gpio_flags flags;
4244 bool active_low = false;
4245 bool single_ended = false;
4246 bool open_drain = false;
4247 bool transitory = false;
4250 desc = of_get_named_gpiod_flags(node, propname,
4253 if (!desc || IS_ERR(desc)) {
4254 /* If it is not there, just return NULL */
4255 if (PTR_ERR(desc) == -ENOENT)
4260 active_low = flags & OF_GPIO_ACTIVE_LOW;
4261 single_ended = flags & OF_GPIO_SINGLE_ENDED;
4262 open_drain = flags & OF_GPIO_OPEN_DRAIN;
4263 transitory = flags & OF_GPIO_TRANSITORY;
4265 ret = gpiod_request(desc, label);
4266 if (ret == -EBUSY && (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4269 return ERR_PTR(ret);
4272 lflags |= GPIO_ACTIVE_LOW;
4276 lflags |= GPIO_OPEN_DRAIN;
4278 lflags |= GPIO_OPEN_SOURCE;
4282 lflags |= GPIO_TRANSITORY;
4284 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4287 return ERR_PTR(ret);
4292 EXPORT_SYMBOL(gpiod_get_from_of_node);
4295 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4296 * @fwnode: handle of the firmware node
4297 * @propname: name of the firmware property representing the GPIO
4298 * @index: index of the GPIO to obtain for the consumer
4299 * @dflags: GPIO initialization flags
4300 * @label: label to attach to the requested GPIO
4302 * This function can be used for drivers that get their configuration
4303 * from opaque firmware.
4305 * The function properly finds the corresponding GPIO using whatever is the
4306 * underlying firmware interface and then makes sure that the GPIO
4307 * descriptor is requested before it is returned to the caller.
4310 * On successful request the GPIO pin is configured in accordance with
4313 * In case of error an ERR_PTR() is returned.
4315 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4316 const char *propname, int index,
4317 enum gpiod_flags dflags,
4320 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4321 unsigned long lflags = 0;
4325 return ERR_PTR(-EINVAL);
4327 if (is_of_node(fwnode)) {
4328 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4333 } else if (is_acpi_node(fwnode)) {
4334 struct acpi_gpio_info info;
4336 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4340 acpi_gpio_update_gpiod_flags(&dflags, &info);
4342 if (info.polarity == GPIO_ACTIVE_LOW)
4343 lflags |= GPIO_ACTIVE_LOW;
4346 /* Currently only ACPI takes this path */
4347 ret = gpiod_request(desc, label);
4349 return ERR_PTR(ret);
4351 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4354 return ERR_PTR(ret);
4359 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4362 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4364 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4365 * @con_id: function within the GPIO consumer
4366 * @index: index of the GPIO to obtain in the consumer
4367 * @flags: optional GPIO initialization flags
4369 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4370 * specified index was assigned to the requested function it will return NULL.
4371 * This is convenient for drivers that need to handle optional GPIOs.
4373 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4376 enum gpiod_flags flags)
4378 struct gpio_desc *desc;
4380 desc = gpiod_get_index(dev, con_id, index, flags);
4382 if (PTR_ERR(desc) == -ENOENT)
4388 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4391 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4392 * @desc: gpio whose value will be assigned
4393 * @name: gpio line name
4394 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4396 * @dflags: gpiod_flags - optional GPIO initialization flags
4398 int gpiod_hog(struct gpio_desc *desc, const char *name,
4399 unsigned long lflags, enum gpiod_flags dflags)
4401 struct gpio_chip *chip;
4402 struct gpio_desc *local_desc;
4406 chip = gpiod_to_chip(desc);
4407 hwnum = gpio_chip_hwgpio(desc);
4410 * FIXME: not very elegant that we call gpiod_configure_flags()
4411 * twice here (once inside gpiochip_request_own_desc() and
4412 * again here), but the gpiochip_request_own_desc() is external
4413 * and cannot really pass the lflags so this is the lesser evil
4414 * at the moment. Pass zero as dflags on this first call so we
4415 * don't screw anything up.
4417 local_desc = gpiochip_request_own_desc(chip, hwnum, name, 0);
4418 if (IS_ERR(local_desc)) {
4419 status = PTR_ERR(local_desc);
4420 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4421 name, chip->label, hwnum, status);
4425 status = gpiod_configure_flags(desc, name, lflags, dflags);
4427 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
4428 name, chip->label, hwnum, status);
4429 gpiochip_free_own_desc(desc);
4433 /* Mark GPIO as hogged so it can be identified and removed later */
4434 set_bit(FLAG_IS_HOGGED, &desc->flags);
4436 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4437 desc_to_gpio(desc), name,
4438 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4439 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4440 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4446 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4447 * @chip: gpio chip to act on
4449 * This is only used by of_gpiochip_remove to free hogged gpios
4451 static void gpiochip_free_hogs(struct gpio_chip *chip)
4455 for (id = 0; id < chip->ngpio; id++) {
4456 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4457 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4462 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4463 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4464 * @con_id: function within the GPIO consumer
4465 * @flags: optional GPIO initialization flags
4467 * This function acquires all the GPIOs defined under a given function.
4469 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4470 * no GPIO has been assigned to the requested function, or another IS_ERR()
4471 * code if an error occurred while trying to acquire the GPIOs.
4473 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4475 enum gpiod_flags flags)
4477 struct gpio_desc *desc;
4478 struct gpio_descs *descs;
4479 struct gpio_array *array_info = NULL;
4480 struct gpio_chip *chip;
4481 int count, bitmap_size;
4483 count = gpiod_count(dev, con_id);
4485 return ERR_PTR(count);
4487 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4489 return ERR_PTR(-ENOMEM);
4491 for (descs->ndescs = 0; descs->ndescs < count; ) {
4492 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4494 gpiod_put_array(descs);
4495 return ERR_CAST(desc);
4498 descs->desc[descs->ndescs] = desc;
4500 chip = gpiod_to_chip(desc);
4502 * If pin hardware number of array member 0 is also 0, select
4503 * its chip as a candidate for fast bitmap processing path.
4505 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4506 struct gpio_descs *array;
4508 bitmap_size = BITS_TO_LONGS(chip->ngpio > count ?
4509 chip->ngpio : count);
4511 array = kzalloc(struct_size(descs, desc, count) +
4512 struct_size(array_info, invert_mask,
4513 3 * bitmap_size), GFP_KERNEL);
4515 gpiod_put_array(descs);
4516 return ERR_PTR(-ENOMEM);
4519 memcpy(array, descs,
4520 struct_size(descs, desc, descs->ndescs + 1));
4524 array_info = (void *)(descs->desc + count);
4525 array_info->get_mask = array_info->invert_mask +
4527 array_info->set_mask = array_info->get_mask +
4530 array_info->desc = descs->desc;
4531 array_info->size = count;
4532 array_info->chip = chip;
4533 bitmap_set(array_info->get_mask, descs->ndescs,
4534 count - descs->ndescs);
4535 bitmap_set(array_info->set_mask, descs->ndescs,
4536 count - descs->ndescs);
4537 descs->info = array_info;
4539 /* Unmark array members which don't belong to the 'fast' chip */
4540 if (array_info && array_info->chip != chip) {
4541 __clear_bit(descs->ndescs, array_info->get_mask);
4542 __clear_bit(descs->ndescs, array_info->set_mask);
4545 * Detect array members which belong to the 'fast' chip
4546 * but their pins are not in hardware order.
4548 else if (array_info &&
4549 gpio_chip_hwgpio(desc) != descs->ndescs) {
4551 * Don't use fast path if all array members processed so
4552 * far belong to the same chip as this one but its pin
4553 * hardware number is different from its array index.
4555 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4558 __clear_bit(descs->ndescs,
4559 array_info->get_mask);
4560 __clear_bit(descs->ndescs,
4561 array_info->set_mask);
4563 } else if (array_info) {
4564 /* Exclude open drain or open source from fast output */
4565 if (gpiochip_line_is_open_drain(chip, descs->ndescs) ||
4566 gpiochip_line_is_open_source(chip, descs->ndescs))
4567 __clear_bit(descs->ndescs,
4568 array_info->set_mask);
4569 /* Identify 'fast' pins which require invertion */
4570 if (gpiod_is_active_low(desc))
4571 __set_bit(descs->ndescs,
4572 array_info->invert_mask);
4579 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4580 array_info->chip->label, array_info->size,
4581 *array_info->get_mask, *array_info->set_mask,
4582 *array_info->invert_mask);
4585 EXPORT_SYMBOL_GPL(gpiod_get_array);
4588 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4590 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4591 * @con_id: function within the GPIO consumer
4592 * @flags: optional GPIO initialization flags
4594 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4595 * assigned to the requested function it will return NULL.
4597 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4599 enum gpiod_flags flags)
4601 struct gpio_descs *descs;
4603 descs = gpiod_get_array(dev, con_id, flags);
4604 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4609 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4612 * gpiod_put - dispose of a GPIO descriptor
4613 * @desc: GPIO descriptor to dispose of
4615 * No descriptor can be used after gpiod_put() has been called on it.
4617 void gpiod_put(struct gpio_desc *desc)
4621 EXPORT_SYMBOL_GPL(gpiod_put);
4624 * gpiod_put_array - dispose of multiple GPIO descriptors
4625 * @descs: struct gpio_descs containing an array of descriptors
4627 void gpiod_put_array(struct gpio_descs *descs)
4631 for (i = 0; i < descs->ndescs; i++)
4632 gpiod_put(descs->desc[i]);
4636 EXPORT_SYMBOL_GPL(gpiod_put_array);
4638 static int __init gpiolib_dev_init(void)
4642 /* Register GPIO sysfs bus */
4643 ret = bus_register(&gpio_bus_type);
4645 pr_err("gpiolib: could not register GPIO bus type\n");
4649 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4651 pr_err("gpiolib: failed to allocate char dev region\n");
4652 bus_unregister(&gpio_bus_type);
4654 gpiolib_initialized = true;
4655 gpiochip_setup_devs();
4659 core_initcall(gpiolib_dev_init);
4661 #ifdef CONFIG_DEBUG_FS
4663 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4666 struct gpio_chip *chip = gdev->chip;
4667 unsigned gpio = gdev->base;
4668 struct gpio_desc *gdesc = &gdev->descs[0];
4673 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4674 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4676 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4682 gpiod_get_direction(gdesc);
4683 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4684 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4685 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4686 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4687 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4688 is_out ? "out" : "in ",
4689 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4690 is_irq ? "IRQ " : "",
4691 active_low ? "ACTIVE LOW" : "");
4692 seq_printf(s, "\n");
4696 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4698 unsigned long flags;
4699 struct gpio_device *gdev = NULL;
4700 loff_t index = *pos;
4704 spin_lock_irqsave(&gpio_lock, flags);
4705 list_for_each_entry(gdev, &gpio_devices, list)
4707 spin_unlock_irqrestore(&gpio_lock, flags);
4710 spin_unlock_irqrestore(&gpio_lock, flags);
4715 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4717 unsigned long flags;
4718 struct gpio_device *gdev = v;
4721 spin_lock_irqsave(&gpio_lock, flags);
4722 if (list_is_last(&gdev->list, &gpio_devices))
4725 ret = list_entry(gdev->list.next, struct gpio_device, list);
4726 spin_unlock_irqrestore(&gpio_lock, flags);
4734 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4738 static int gpiolib_seq_show(struct seq_file *s, void *v)
4740 struct gpio_device *gdev = v;
4741 struct gpio_chip *chip = gdev->chip;
4742 struct device *parent;
4745 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4746 dev_name(&gdev->dev));
4750 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4751 dev_name(&gdev->dev),
4752 gdev->base, gdev->base + gdev->ngpio - 1);
4753 parent = chip->parent;
4755 seq_printf(s, ", parent: %s/%s",
4756 parent->bus ? parent->bus->name : "no-bus",
4759 seq_printf(s, ", %s", chip->label);
4760 if (chip->can_sleep)
4761 seq_printf(s, ", can sleep");
4762 seq_printf(s, ":\n");
4765 chip->dbg_show(s, chip);
4767 gpiolib_dbg_show(s, gdev);
4772 static const struct seq_operations gpiolib_seq_ops = {
4773 .start = gpiolib_seq_start,
4774 .next = gpiolib_seq_next,
4775 .stop = gpiolib_seq_stop,
4776 .show = gpiolib_seq_show,
4779 static int gpiolib_open(struct inode *inode, struct file *file)
4781 return seq_open(file, &gpiolib_seq_ops);
4784 static const struct file_operations gpiolib_operations = {
4785 .owner = THIS_MODULE,
4786 .open = gpiolib_open,
4788 .llseek = seq_lseek,
4789 .release = seq_release,
4792 static int __init gpiolib_debugfs_init(void)
4794 /* /sys/kernel/debug/gpio */
4795 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4796 NULL, NULL, &gpiolib_operations);
4799 subsys_initcall(gpiolib_debugfs_init);
4801 #endif /* DEBUG_FS */