1 #include <linux/bitops.h>
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/interrupt.h>
6 #include <linux/spinlock.h>
7 #include <linux/list.h>
8 #include <linux/device.h>
10 #include <linux/debugfs.h>
11 #include <linux/seq_file.h>
12 #include <linux/gpio.h>
13 #include <linux/of_gpio.h>
14 #include <linux/idr.h>
15 #include <linux/slab.h>
16 #include <linux/acpi.h>
17 #include <linux/gpio/driver.h>
18 #include <linux/gpio/machine.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <linux/anon_inodes.h>
25 #include <linux/file.h>
26 #include <linux/kfifo.h>
27 #include <linux/poll.h>
28 #include <linux/timekeeping.h>
29 #include <uapi/linux/gpio.h>
33 #define CREATE_TRACE_POINTS
34 #include <trace/events/gpio.h>
36 /* Implementation infrastructure for GPIO interfaces.
38 * The GPIO programming interface allows for inlining speed-critical
39 * get/set operations for common cases, so that access to SOC-integrated
40 * GPIOs can sometimes cost only an instruction or two per bit.
44 /* When debugging, extend minimal trust to callers and platform code.
45 * Also emit diagnostic messages that may help initial bringup, when
46 * board setup or driver bugs are most common.
48 * Otherwise, minimize overhead in what may be bitbanging codepaths.
51 #define extra_checks 1
53 #define extra_checks 0
56 /* Device and char device-related information */
57 static DEFINE_IDA(gpio_ida);
58 static dev_t gpio_devt;
59 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
60 static struct bus_type gpio_bus_type = {
64 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
65 * While any GPIO is requested, its gpio_chip is not removable;
66 * each GPIO's "requested" flag serves as a lock and refcount.
68 DEFINE_SPINLOCK(gpio_lock);
70 static DEFINE_MUTEX(gpio_lookup_lock);
71 static LIST_HEAD(gpio_lookup_list);
72 LIST_HEAD(gpio_devices);
74 static void gpiochip_free_hogs(struct gpio_chip *chip);
75 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
76 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
77 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
79 static bool gpiolib_initialized;
81 static inline void desc_set_label(struct gpio_desc *d, const char *label)
87 * Convert a GPIO number to its descriptor
89 struct gpio_desc *gpio_to_desc(unsigned gpio)
91 struct gpio_device *gdev;
94 spin_lock_irqsave(&gpio_lock, flags);
96 list_for_each_entry(gdev, &gpio_devices, list) {
97 if (gdev->base <= gpio &&
98 gdev->base + gdev->ngpio > gpio) {
99 spin_unlock_irqrestore(&gpio_lock, flags);
100 return &gdev->descs[gpio - gdev->base];
104 spin_unlock_irqrestore(&gpio_lock, flags);
106 if (!gpio_is_valid(gpio))
107 WARN(1, "invalid GPIO %d\n", gpio);
111 EXPORT_SYMBOL_GPL(gpio_to_desc);
114 * Get the GPIO descriptor corresponding to the given hw number for this chip.
116 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
119 struct gpio_device *gdev = chip->gpiodev;
121 if (hwnum >= gdev->ngpio)
122 return ERR_PTR(-EINVAL);
124 return &gdev->descs[hwnum];
128 * Convert a GPIO descriptor to the integer namespace.
129 * This should disappear in the future but is needed since we still
130 * use GPIO numbers for error messages and sysfs nodes
132 int desc_to_gpio(const struct gpio_desc *desc)
134 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
136 EXPORT_SYMBOL_GPL(desc_to_gpio);
140 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
141 * @desc: descriptor to return the chip of
143 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
145 if (!desc || !desc->gdev || !desc->gdev->chip)
147 return desc->gdev->chip;
149 EXPORT_SYMBOL_GPL(gpiod_to_chip);
151 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
152 static int gpiochip_find_base(int ngpio)
154 struct gpio_device *gdev;
155 int base = ARCH_NR_GPIOS - ngpio;
157 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
158 /* found a free space? */
159 if (gdev->base + gdev->ngpio <= base)
162 /* nope, check the space right before the chip */
163 base = gdev->base - ngpio;
166 if (gpio_is_valid(base)) {
167 pr_debug("%s: found new base at %d\n", __func__, base);
170 pr_err("%s: cannot find free range\n", __func__);
176 * gpiod_get_direction - return the current direction of a GPIO
177 * @desc: GPIO to get the direction of
179 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
181 * This function may sleep if gpiod_cansleep() is true.
183 int gpiod_get_direction(struct gpio_desc *desc)
185 struct gpio_chip *chip;
187 int status = -EINVAL;
189 chip = gpiod_to_chip(desc);
190 offset = gpio_chip_hwgpio(desc);
192 if (!chip->get_direction)
195 status = chip->get_direction(chip, offset);
197 /* GPIOF_DIR_IN, or other positive */
199 clear_bit(FLAG_IS_OUT, &desc->flags);
203 set_bit(FLAG_IS_OUT, &desc->flags);
207 EXPORT_SYMBOL_GPL(gpiod_get_direction);
210 * Add a new chip to the global chips list, keeping the list of chips sorted
211 * by range(means [base, base + ngpio - 1]) order.
213 * Return -EBUSY if the new chip overlaps with some other chip's integer
216 static int gpiodev_add_to_list(struct gpio_device *gdev)
218 struct gpio_device *prev, *next;
220 if (list_empty(&gpio_devices)) {
221 /* initial entry in list */
222 list_add_tail(&gdev->list, &gpio_devices);
226 next = list_entry(gpio_devices.next, struct gpio_device, list);
227 if (gdev->base + gdev->ngpio <= next->base) {
228 /* add before first entry */
229 list_add(&gdev->list, &gpio_devices);
233 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
234 if (prev->base + prev->ngpio <= gdev->base) {
235 /* add behind last entry */
236 list_add_tail(&gdev->list, &gpio_devices);
240 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
241 /* at the end of the list */
242 if (&next->list == &gpio_devices)
245 /* add between prev and next */
246 if (prev->base + prev->ngpio <= gdev->base
247 && gdev->base + gdev->ngpio <= next->base) {
248 list_add(&gdev->list, &prev->list);
253 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
258 * Convert a GPIO name to its descriptor
260 static struct gpio_desc *gpio_name_to_desc(const char * const name)
262 struct gpio_device *gdev;
265 spin_lock_irqsave(&gpio_lock, flags);
267 list_for_each_entry(gdev, &gpio_devices, list) {
270 for (i = 0; i != gdev->ngpio; ++i) {
271 struct gpio_desc *desc = &gdev->descs[i];
273 if (!desc->name || !name)
276 if (!strcmp(desc->name, name)) {
277 spin_unlock_irqrestore(&gpio_lock, flags);
283 spin_unlock_irqrestore(&gpio_lock, flags);
289 * Takes the names from gc->names and checks if they are all unique. If they
290 * are, they are assigned to their gpio descriptors.
292 * Warning if one of the names is already used for a different GPIO.
294 static int gpiochip_set_desc_names(struct gpio_chip *gc)
296 struct gpio_device *gdev = gc->gpiodev;
302 /* First check all names if they are unique */
303 for (i = 0; i != gc->ngpio; ++i) {
304 struct gpio_desc *gpio;
306 gpio = gpio_name_to_desc(gc->names[i]);
309 "Detected name collision for GPIO name '%s'\n",
313 /* Then add all names to the GPIO descriptors */
314 for (i = 0; i != gc->ngpio; ++i)
315 gdev->descs[i].name = gc->names[i];
321 * GPIO line handle management
325 * struct linehandle_state - contains the state of a userspace handle
326 * @gdev: the GPIO device the handle pertains to
327 * @label: consumer label used to tag descriptors
328 * @descs: the GPIO descriptors held by this handle
329 * @numdescs: the number of descriptors held in the descs array
331 struct linehandle_state {
332 struct gpio_device *gdev;
334 struct gpio_desc *descs[GPIOHANDLES_MAX];
338 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
339 (GPIOHANDLE_REQUEST_INPUT | \
340 GPIOHANDLE_REQUEST_OUTPUT | \
341 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
342 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
343 GPIOHANDLE_REQUEST_OPEN_SOURCE)
345 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
348 struct linehandle_state *lh = filep->private_data;
349 void __user *ip = (void __user *)arg;
350 struct gpiohandle_data ghd;
353 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
356 memset(&ghd, 0, sizeof(ghd));
358 /* TODO: check if descriptors are really input */
359 for (i = 0; i < lh->numdescs; i++) {
360 val = gpiod_get_value_cansleep(lh->descs[i]);
366 if (copy_to_user(ip, &ghd, sizeof(ghd)))
370 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
371 int vals[GPIOHANDLES_MAX];
373 /* TODO: check if descriptors are really output */
374 if (copy_from_user(&ghd, ip, sizeof(ghd)))
377 /* Clamp all values to [0,1] */
378 for (i = 0; i < lh->numdescs; i++)
379 vals[i] = !!ghd.values[i];
381 /* Reuse the array setting function */
382 gpiod_set_array_value_complex(false,
393 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
396 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
400 static int linehandle_release(struct inode *inode, struct file *filep)
402 struct linehandle_state *lh = filep->private_data;
403 struct gpio_device *gdev = lh->gdev;
406 for (i = 0; i < lh->numdescs; i++)
407 gpiod_free(lh->descs[i]);
410 put_device(&gdev->dev);
414 static const struct file_operations linehandle_fileops = {
415 .release = linehandle_release,
416 .owner = THIS_MODULE,
417 .llseek = noop_llseek,
418 .unlocked_ioctl = linehandle_ioctl,
420 .compat_ioctl = linehandle_ioctl_compat,
424 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
426 struct gpiohandle_request handlereq;
427 struct linehandle_state *lh;
431 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
433 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
436 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
440 get_device(&gdev->dev);
442 /* Make sure this is terminated */
443 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
444 if (strlen(handlereq.consumer_label)) {
445 lh->label = kstrdup(handlereq.consumer_label,
453 /* Request each GPIO */
454 for (i = 0; i < handlereq.lines; i++) {
455 u32 offset = handlereq.lineoffsets[i];
456 u32 lflags = handlereq.flags;
457 struct gpio_desc *desc;
459 if (offset >= gdev->ngpio) {
464 /* Return an error if a unknown flag is set */
465 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) {
470 desc = &gdev->descs[offset];
471 ret = gpiod_request(desc, lh->label);
476 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
477 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
478 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
479 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
480 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
481 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
484 * Lines have to be requested explicitly for input
485 * or output, else the line will be treated "as is".
487 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
488 int val = !!handlereq.default_values[i];
490 ret = gpiod_direction_output(desc, val);
493 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
494 ret = gpiod_direction_input(desc);
498 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
501 /* Let i point at the last handle */
503 lh->numdescs = handlereq.lines;
505 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
511 file = anon_inode_getfile("gpio-linehandle",
514 O_RDONLY | O_CLOEXEC);
517 goto out_put_unused_fd;
521 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
523 * fput() will trigger the release() callback, so do not go onto
524 * the regular error cleanup path here.
531 fd_install(fd, file);
533 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
542 gpiod_free(lh->descs[i]);
546 put_device(&gdev->dev);
551 * GPIO line event management
555 * struct lineevent_state - contains the state of a userspace event
556 * @gdev: the GPIO device the event pertains to
557 * @label: consumer label used to tag descriptors
558 * @desc: the GPIO descriptor held by this event
559 * @eflags: the event flags this line was requested with
560 * @irq: the interrupt that trigger in response to events on this GPIO
561 * @wait: wait queue that handles blocking reads of events
562 * @events: KFIFO for the GPIO events
563 * @read_lock: mutex lock to protect reads from colliding with adding
564 * new events to the FIFO
566 struct lineevent_state {
567 struct gpio_device *gdev;
569 struct gpio_desc *desc;
572 wait_queue_head_t wait;
573 DECLARE_KFIFO(events, struct gpioevent_data, 16);
574 struct mutex read_lock;
577 #define GPIOEVENT_REQUEST_VALID_FLAGS \
578 (GPIOEVENT_REQUEST_RISING_EDGE | \
579 GPIOEVENT_REQUEST_FALLING_EDGE)
581 static unsigned int lineevent_poll(struct file *filep,
582 struct poll_table_struct *wait)
584 struct lineevent_state *le = filep->private_data;
585 unsigned int events = 0;
587 poll_wait(filep, &le->wait, wait);
589 if (!kfifo_is_empty(&le->events))
590 events = POLLIN | POLLRDNORM;
596 static ssize_t lineevent_read(struct file *filep,
601 struct lineevent_state *le = filep->private_data;
605 if (count < sizeof(struct gpioevent_data))
609 if (kfifo_is_empty(&le->events)) {
610 if (filep->f_flags & O_NONBLOCK)
613 ret = wait_event_interruptible(le->wait,
614 !kfifo_is_empty(&le->events));
619 if (mutex_lock_interruptible(&le->read_lock))
621 ret = kfifo_to_user(&le->events, buf, count, &copied);
622 mutex_unlock(&le->read_lock);
628 * If we couldn't read anything from the fifo (a different
629 * thread might have been faster) we either return -EAGAIN if
630 * the file descriptor is non-blocking, otherwise we go back to
631 * sleep and wait for more data to arrive.
633 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
636 } while (copied == 0);
641 static int lineevent_release(struct inode *inode, struct file *filep)
643 struct lineevent_state *le = filep->private_data;
644 struct gpio_device *gdev = le->gdev;
646 free_irq(le->irq, le);
647 gpiod_free(le->desc);
650 put_device(&gdev->dev);
654 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
657 struct lineevent_state *le = filep->private_data;
658 void __user *ip = (void __user *)arg;
659 struct gpiohandle_data ghd;
662 * We can get the value for an event line but not set it,
663 * because it is input by definition.
665 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
668 memset(&ghd, 0, sizeof(ghd));
670 val = gpiod_get_value_cansleep(le->desc);
675 if (copy_to_user(ip, &ghd, sizeof(ghd)))
684 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
687 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
691 static const struct file_operations lineevent_fileops = {
692 .release = lineevent_release,
693 .read = lineevent_read,
694 .poll = lineevent_poll,
695 .owner = THIS_MODULE,
696 .llseek = noop_llseek,
697 .unlocked_ioctl = lineevent_ioctl,
699 .compat_ioctl = lineevent_ioctl_compat,
703 static irqreturn_t lineevent_irq_thread(int irq, void *p)
705 struct lineevent_state *le = p;
706 struct gpioevent_data ge;
709 ge.timestamp = ktime_get_real_ns();
711 if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
712 int level = gpiod_get_value_cansleep(le->desc);
715 /* Emit low-to-high event */
716 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
718 /* Emit high-to-low event */
719 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
720 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
721 /* Emit low-to-high event */
722 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
723 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
724 /* Emit high-to-low event */
725 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
730 ret = kfifo_put(&le->events, ge);
732 wake_up_poll(&le->wait, POLLIN);
737 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
739 struct gpioevent_request eventreq;
740 struct lineevent_state *le;
741 struct gpio_desc *desc;
750 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
753 le = kzalloc(sizeof(*le), GFP_KERNEL);
757 get_device(&gdev->dev);
759 /* Make sure this is terminated */
760 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
761 if (strlen(eventreq.consumer_label)) {
762 le->label = kstrdup(eventreq.consumer_label,
770 offset = eventreq.lineoffset;
771 lflags = eventreq.handleflags;
772 eflags = eventreq.eventflags;
774 if (offset >= gdev->ngpio) {
779 /* Return an error if a unknown flag is set */
780 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
781 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
786 /* This is just wrong: we don't look for events on output lines */
787 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
792 desc = &gdev->descs[offset];
793 ret = gpiod_request(desc, le->label);
799 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
800 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
801 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
802 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
803 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
804 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
806 ret = gpiod_direction_input(desc);
810 le->irq = gpiod_to_irq(desc);
816 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
817 irqflags |= IRQF_TRIGGER_RISING;
818 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
819 irqflags |= IRQF_TRIGGER_FALLING;
820 irqflags |= IRQF_ONESHOT;
821 irqflags |= IRQF_SHARED;
823 INIT_KFIFO(le->events);
824 init_waitqueue_head(&le->wait);
825 mutex_init(&le->read_lock);
827 /* Request a thread to read the events */
828 ret = request_threaded_irq(le->irq,
830 lineevent_irq_thread,
837 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
843 file = anon_inode_getfile("gpio-event",
846 O_RDONLY | O_CLOEXEC);
849 goto out_put_unused_fd;
853 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
855 * fput() will trigger the release() callback, so do not go onto
856 * the regular error cleanup path here.
863 fd_install(fd, file);
870 free_irq(le->irq, le);
872 gpiod_free(le->desc);
877 put_device(&gdev->dev);
882 * gpio_ioctl() - ioctl handler for the GPIO chardev
884 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
886 struct gpio_device *gdev = filp->private_data;
887 struct gpio_chip *chip = gdev->chip;
888 void __user *ip = (void __user *)arg;
890 /* We fail any subsequent ioctl():s when the chip is gone */
894 /* Fill in the struct and pass to userspace */
895 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
896 struct gpiochip_info chipinfo;
898 memset(&chipinfo, 0, sizeof(chipinfo));
900 strncpy(chipinfo.name, dev_name(&gdev->dev),
901 sizeof(chipinfo.name));
902 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
903 strncpy(chipinfo.label, gdev->label,
904 sizeof(chipinfo.label));
905 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
906 chipinfo.lines = gdev->ngpio;
907 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
910 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
911 struct gpioline_info lineinfo;
912 struct gpio_desc *desc;
914 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
916 if (lineinfo.line_offset >= gdev->ngpio)
919 desc = &gdev->descs[lineinfo.line_offset];
921 strncpy(lineinfo.name, desc->name,
922 sizeof(lineinfo.name));
923 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
925 lineinfo.name[0] = '\0';
928 strncpy(lineinfo.consumer, desc->label,
929 sizeof(lineinfo.consumer));
930 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
932 lineinfo.consumer[0] = '\0';
936 * Userspace only need to know that the kernel is using
937 * this GPIO so it can't use it.
940 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
941 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
942 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
943 test_bit(FLAG_EXPORT, &desc->flags) ||
944 test_bit(FLAG_SYSFS, &desc->flags))
945 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
946 if (test_bit(FLAG_IS_OUT, &desc->flags))
947 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
948 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
949 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
950 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
951 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
952 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
953 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
955 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
958 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
959 return linehandle_create(gdev, ip);
960 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
961 return lineevent_create(gdev, ip);
967 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
970 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
975 * gpio_chrdev_open() - open the chardev for ioctl operations
976 * @inode: inode for this chardev
977 * @filp: file struct for storing private data
978 * Returns 0 on success
980 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
982 struct gpio_device *gdev = container_of(inode->i_cdev,
983 struct gpio_device, chrdev);
985 /* Fail on open if the backing gpiochip is gone */
988 get_device(&gdev->dev);
989 filp->private_data = gdev;
991 return nonseekable_open(inode, filp);
995 * gpio_chrdev_release() - close chardev after ioctl operations
996 * @inode: inode for this chardev
997 * @filp: file struct for storing private data
998 * Returns 0 on success
1000 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1002 struct gpio_device *gdev = container_of(inode->i_cdev,
1003 struct gpio_device, chrdev);
1005 put_device(&gdev->dev);
1010 static const struct file_operations gpio_fileops = {
1011 .release = gpio_chrdev_release,
1012 .open = gpio_chrdev_open,
1013 .owner = THIS_MODULE,
1014 .llseek = no_llseek,
1015 .unlocked_ioctl = gpio_ioctl,
1016 #ifdef CONFIG_COMPAT
1017 .compat_ioctl = gpio_ioctl_compat,
1021 static void gpiodevice_release(struct device *dev)
1023 struct gpio_device *gdev = dev_get_drvdata(dev);
1025 list_del(&gdev->list);
1026 ida_simple_remove(&gpio_ida, gdev->id);
1032 static int gpiochip_setup_dev(struct gpio_device *gdev)
1036 cdev_init(&gdev->chrdev, &gpio_fileops);
1037 gdev->chrdev.owner = THIS_MODULE;
1038 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1040 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1044 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1045 MAJOR(gpio_devt), gdev->id);
1047 status = gpiochip_sysfs_register(gdev);
1049 goto err_remove_device;
1051 /* From this point, the .release() function cleans up gpio_device */
1052 gdev->dev.release = gpiodevice_release;
1053 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1054 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1055 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1060 cdev_device_del(&gdev->chrdev, &gdev->dev);
1064 static void gpiochip_setup_devs(void)
1066 struct gpio_device *gdev;
1069 list_for_each_entry(gdev, &gpio_devices, list) {
1070 err = gpiochip_setup_dev(gdev);
1072 pr_err("%s: Failed to initialize gpio device (%d)\n",
1073 dev_name(&gdev->dev), err);
1078 * gpiochip_add_data() - register a gpio_chip
1079 * @chip: the chip to register, with chip->base initialized
1080 * Context: potentially before irqs will work
1082 * Returns a negative errno if the chip can't be registered, such as
1083 * because the chip->base is invalid or already associated with a
1084 * different chip. Otherwise it returns zero as a success code.
1086 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1087 * can be freely used, the chip->parent device must be registered before
1088 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1089 * for GPIOs will fail rudely.
1091 * gpiochip_add_data() must only be called after gpiolib initialization,
1092 * ie after core_initcall().
1094 * If chip->base is negative, this requests dynamic assignment of
1095 * a range of valid GPIOs.
1097 int gpiochip_add_data(struct gpio_chip *chip, void *data)
1099 unsigned long flags;
1102 int base = chip->base;
1103 struct gpio_device *gdev;
1106 * First: allocate and populate the internal stat container, and
1107 * set up the struct device.
1109 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1112 gdev->dev.bus = &gpio_bus_type;
1114 chip->gpiodev = gdev;
1116 gdev->dev.parent = chip->parent;
1117 gdev->dev.of_node = chip->parent->of_node;
1120 #ifdef CONFIG_OF_GPIO
1121 /* If the gpiochip has an assigned OF node this takes precedence */
1123 gdev->dev.of_node = chip->of_node;
1126 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1131 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1132 device_initialize(&gdev->dev);
1133 dev_set_drvdata(&gdev->dev, gdev);
1134 if (chip->parent && chip->parent->driver)
1135 gdev->owner = chip->parent->driver->owner;
1136 else if (chip->owner)
1137 /* TODO: remove chip->owner */
1138 gdev->owner = chip->owner;
1140 gdev->owner = THIS_MODULE;
1142 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1148 if (chip->ngpio == 0) {
1149 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1151 goto err_free_descs;
1155 gdev->label = kstrdup(chip->label, GFP_KERNEL);
1157 gdev->label = kstrdup("unknown", GFP_KERNEL);
1160 goto err_free_descs;
1163 gdev->ngpio = chip->ngpio;
1166 spin_lock_irqsave(&gpio_lock, flags);
1169 * TODO: this allocates a Linux GPIO number base in the global
1170 * GPIO numberspace for this chip. In the long run we want to
1171 * get *rid* of this numberspace and use only descriptors, but
1172 * it may be a pipe dream. It will not happen before we get rid
1173 * of the sysfs interface anyways.
1176 base = gpiochip_find_base(chip->ngpio);
1179 spin_unlock_irqrestore(&gpio_lock, flags);
1180 goto err_free_label;
1183 * TODO: it should not be necessary to reflect the assigned
1184 * base outside of the GPIO subsystem. Go over drivers and
1185 * see if anyone makes use of this, else drop this and assign
1192 status = gpiodev_add_to_list(gdev);
1194 spin_unlock_irqrestore(&gpio_lock, flags);
1195 goto err_free_label;
1198 spin_unlock_irqrestore(&gpio_lock, flags);
1200 for (i = 0; i < chip->ngpio; i++) {
1201 struct gpio_desc *desc = &gdev->descs[i];
1205 * REVISIT: most hardware initializes GPIOs as inputs
1206 * (often with pullups enabled) so power usage is
1207 * minimized. Linux code should set the gpio direction
1208 * first thing; but until it does, and in case
1209 * chip->get_direction is not set, we may expose the
1210 * wrong direction in sysfs.
1213 if (chip->get_direction) {
1215 * If we have .get_direction, set up the initial
1216 * direction flag from the hardware.
1218 int dir = chip->get_direction(chip, i);
1221 set_bit(FLAG_IS_OUT, &desc->flags);
1222 } else if (!chip->direction_input) {
1224 * If the chip lacks the .direction_input callback
1225 * we logically assume all lines are outputs.
1227 set_bit(FLAG_IS_OUT, &desc->flags);
1231 #ifdef CONFIG_PINCTRL
1232 INIT_LIST_HEAD(&gdev->pin_ranges);
1235 status = gpiochip_set_desc_names(chip);
1237 goto err_remove_from_list;
1239 status = gpiochip_irqchip_init_valid_mask(chip);
1241 goto err_remove_from_list;
1243 status = of_gpiochip_add(chip);
1245 goto err_remove_chip;
1247 acpi_gpiochip_add(chip);
1250 * By first adding the chardev, and then adding the device,
1251 * we get a device node entry in sysfs under
1252 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1253 * coldplug of device nodes and other udev business.
1254 * We can do this only if gpiolib has been initialized.
1255 * Otherwise, defer until later.
1257 if (gpiolib_initialized) {
1258 status = gpiochip_setup_dev(gdev);
1260 goto err_remove_chip;
1265 acpi_gpiochip_remove(chip);
1266 gpiochip_free_hogs(chip);
1267 of_gpiochip_remove(chip);
1268 gpiochip_irqchip_free_valid_mask(chip);
1269 err_remove_from_list:
1270 spin_lock_irqsave(&gpio_lock, flags);
1271 list_del(&gdev->list);
1272 spin_unlock_irqrestore(&gpio_lock, flags);
1278 ida_simple_remove(&gpio_ida, gdev->id);
1279 /* failures here can mean systems won't boot... */
1280 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1281 gdev->base, gdev->base + gdev->ngpio - 1,
1282 chip->label ? : "generic");
1286 EXPORT_SYMBOL_GPL(gpiochip_add_data);
1289 * gpiochip_get_data() - get per-subdriver data for the chip
1291 void *gpiochip_get_data(struct gpio_chip *chip)
1293 return chip->gpiodev->data;
1295 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1298 * gpiochip_remove() - unregister a gpio_chip
1299 * @chip: the chip to unregister
1301 * A gpio_chip with any GPIOs still requested may not be removed.
1303 void gpiochip_remove(struct gpio_chip *chip)
1305 struct gpio_device *gdev = chip->gpiodev;
1306 struct gpio_desc *desc;
1307 unsigned long flags;
1309 bool requested = false;
1311 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1312 gpiochip_sysfs_unregister(gdev);
1313 gpiochip_free_hogs(chip);
1314 /* Numb the device, cancelling all outstanding operations */
1316 gpiochip_irqchip_remove(chip);
1317 acpi_gpiochip_remove(chip);
1318 gpiochip_remove_pin_ranges(chip);
1319 of_gpiochip_remove(chip);
1321 * We accept no more calls into the driver from this point, so
1322 * NULL the driver data pointer
1326 spin_lock_irqsave(&gpio_lock, flags);
1327 for (i = 0; i < gdev->ngpio; i++) {
1328 desc = &gdev->descs[i];
1329 if (test_bit(FLAG_REQUESTED, &desc->flags))
1332 spin_unlock_irqrestore(&gpio_lock, flags);
1335 dev_crit(&gdev->dev,
1336 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1339 * The gpiochip side puts its use of the device to rest here:
1340 * if there are no userspace clients, the chardev and device will
1341 * be removed, else it will be dangling until the last user is
1344 cdev_device_del(&gdev->chrdev, &gdev->dev);
1345 put_device(&gdev->dev);
1347 EXPORT_SYMBOL_GPL(gpiochip_remove);
1349 static void devm_gpio_chip_release(struct device *dev, void *res)
1351 struct gpio_chip *chip = *(struct gpio_chip **)res;
1353 gpiochip_remove(chip);
1356 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1359 struct gpio_chip **r = res;
1370 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1371 * @dev: the device pointer on which irq_chip belongs to.
1372 * @chip: the chip to register, with chip->base initialized
1373 * Context: potentially before irqs will work
1375 * Returns a negative errno if the chip can't be registered, such as
1376 * because the chip->base is invalid or already associated with a
1377 * different chip. Otherwise it returns zero as a success code.
1379 * The gpio chip automatically be released when the device is unbound.
1381 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1384 struct gpio_chip **ptr;
1387 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1392 ret = gpiochip_add_data(chip, data);
1399 devres_add(dev, ptr);
1403 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1406 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1407 * @dev: device for which which resource was allocated
1408 * @chip: the chip to remove
1410 * A gpio_chip with any GPIOs still requested may not be removed.
1412 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1416 ret = devres_release(dev, devm_gpio_chip_release,
1417 devm_gpio_chip_match, chip);
1420 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1423 * gpiochip_find() - iterator for locating a specific gpio_chip
1424 * @data: data to pass to match function
1425 * @callback: Callback function to check gpio_chip
1427 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1428 * determined by a user supplied @match callback. The callback should return
1429 * 0 if the device doesn't match and non-zero if it does. If the callback is
1430 * non-zero, this function will return to the caller and not iterate over any
1433 struct gpio_chip *gpiochip_find(void *data,
1434 int (*match)(struct gpio_chip *chip,
1437 struct gpio_device *gdev;
1438 struct gpio_chip *chip = NULL;
1439 unsigned long flags;
1441 spin_lock_irqsave(&gpio_lock, flags);
1442 list_for_each_entry(gdev, &gpio_devices, list)
1443 if (gdev->chip && match(gdev->chip, data)) {
1448 spin_unlock_irqrestore(&gpio_lock, flags);
1452 EXPORT_SYMBOL_GPL(gpiochip_find);
1454 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1456 const char *name = data;
1458 return !strcmp(chip->label, name);
1461 static struct gpio_chip *find_chip_by_name(const char *name)
1463 return gpiochip_find((void *)name, gpiochip_match_name);
1466 #ifdef CONFIG_GPIOLIB_IRQCHIP
1469 * The following is irqchip helper code for gpiochips.
1472 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1476 if (!gpiochip->irq_need_valid_mask)
1479 gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
1480 sizeof(long), GFP_KERNEL);
1481 if (!gpiochip->irq_valid_mask)
1484 /* Assume by default all GPIOs are valid */
1485 for (i = 0; i < gpiochip->ngpio; i++)
1486 set_bit(i, gpiochip->irq_valid_mask);
1491 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1493 kfree(gpiochip->irq_valid_mask);
1494 gpiochip->irq_valid_mask = NULL;
1497 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1498 unsigned int offset)
1500 /* No mask means all valid */
1501 if (likely(!gpiochip->irq_valid_mask))
1503 return test_bit(offset, gpiochip->irq_valid_mask);
1507 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1508 * @gpiochip: the gpiochip to set the irqchip chain to
1509 * @irqchip: the irqchip to chain to the gpiochip
1510 * @parent_irq: the irq number corresponding to the parent IRQ for this
1512 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1513 * coming out of the gpiochip. If the interrupt is nested rather than
1514 * cascaded, pass NULL in this handler argument
1516 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1517 struct irq_chip *irqchip,
1518 unsigned int parent_irq,
1519 irq_flow_handler_t parent_handler)
1521 unsigned int offset;
1523 if (!gpiochip->irqdomain) {
1524 chip_err(gpiochip, "called %s before setting up irqchip\n",
1529 if (parent_handler) {
1530 if (gpiochip->can_sleep) {
1532 "you cannot have chained interrupts on a "
1533 "chip that may sleep\n");
1537 * The parent irqchip is already using the chip_data for this
1538 * irqchip, so our callbacks simply use the handler_data.
1540 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1543 gpiochip->irq_chained_parent = parent_irq;
1546 /* Set the parent IRQ for all affected IRQs */
1547 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1548 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1550 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
1556 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1557 * @gpiochip: the gpiochip to set the irqchip chain to
1558 * @irqchip: the irqchip to chain to the gpiochip
1559 * @parent_irq: the irq number corresponding to the parent IRQ for this
1561 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1562 * coming out of the gpiochip. If the interrupt is nested rather than
1563 * cascaded, pass NULL in this handler argument
1565 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1566 struct irq_chip *irqchip,
1567 unsigned int parent_irq,
1568 irq_flow_handler_t parent_handler)
1570 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1573 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1576 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1577 * @gpiochip: the gpiochip to set the irqchip nested handler to
1578 * @irqchip: the irqchip to nest to the gpiochip
1579 * @parent_irq: the irq number corresponding to the parent IRQ for this
1582 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1583 struct irq_chip *irqchip,
1584 unsigned int parent_irq)
1586 if (!gpiochip->irq_nested) {
1587 chip_err(gpiochip, "tried to nest a chained gpiochip\n");
1590 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1593 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1596 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1597 * @d: the irqdomain used by this irqchip
1598 * @irq: the global irq number used by this GPIO irqchip irq
1599 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1601 * This function will set up the mapping for a certain IRQ line on a
1602 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1603 * stored inside the gpiochip.
1605 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1606 irq_hw_number_t hwirq)
1608 struct gpio_chip *chip = d->host_data;
1610 irq_set_chip_data(irq, chip);
1612 * This lock class tells lockdep that GPIO irqs are in a different
1613 * category than their parents, so it won't report false recursion.
1615 irq_set_lockdep_class(irq, chip->lock_key);
1616 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1617 /* Chips that use nested thread handlers have them marked */
1618 if (chip->irq_nested)
1619 irq_set_nested_thread(irq, 1);
1620 irq_set_noprobe(irq);
1623 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1624 * is passed as default type.
1626 if (chip->irq_default_type != IRQ_TYPE_NONE)
1627 irq_set_irq_type(irq, chip->irq_default_type);
1632 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1634 struct gpio_chip *chip = d->host_data;
1636 if (chip->irq_nested)
1637 irq_set_nested_thread(irq, 0);
1638 irq_set_chip_and_handler(irq, NULL, NULL);
1639 irq_set_chip_data(irq, NULL);
1642 static const struct irq_domain_ops gpiochip_domain_ops = {
1643 .map = gpiochip_irq_map,
1644 .unmap = gpiochip_irq_unmap,
1645 /* Virtually all GPIO irqchips are twocell:ed */
1646 .xlate = irq_domain_xlate_twocell,
1649 static int gpiochip_irq_reqres(struct irq_data *d)
1651 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1653 if (!try_module_get(chip->gpiodev->owner))
1656 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1658 "unable to lock HW IRQ %lu for IRQ\n",
1660 module_put(chip->gpiodev->owner);
1666 static void gpiochip_irq_relres(struct irq_data *d)
1668 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1670 gpiochip_unlock_as_irq(chip, d->hwirq);
1671 module_put(chip->gpiodev->owner);
1674 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1676 return irq_find_mapping(chip->irqdomain, offset);
1680 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1681 * @gpiochip: the gpiochip to remove the irqchip from
1683 * This is called only from gpiochip_remove()
1685 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1687 unsigned int offset;
1689 acpi_gpiochip_free_interrupts(gpiochip);
1691 if (gpiochip->irq_chained_parent) {
1692 irq_set_chained_handler(gpiochip->irq_chained_parent, NULL);
1693 irq_set_handler_data(gpiochip->irq_chained_parent, NULL);
1696 /* Remove all IRQ mappings and delete the domain */
1697 if (gpiochip->irqdomain) {
1698 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1699 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1701 irq_dispose_mapping(
1702 irq_find_mapping(gpiochip->irqdomain, offset));
1704 irq_domain_remove(gpiochip->irqdomain);
1707 if (gpiochip->irqchip) {
1708 gpiochip->irqchip->irq_request_resources = NULL;
1709 gpiochip->irqchip->irq_release_resources = NULL;
1710 gpiochip->irqchip = NULL;
1713 gpiochip_irqchip_free_valid_mask(gpiochip);
1717 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1718 * @gpiochip: the gpiochip to add the irqchip to
1719 * @irqchip: the irqchip to add to the gpiochip
1720 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1721 * allocate gpiochip irqs from
1722 * @handler: the irq handler to use (often a predefined irq core function)
1723 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1724 * to have the core avoid setting up any default type in the hardware.
1725 * @nested: whether this is a nested irqchip calling handle_nested_irq()
1726 * in its IRQ handler
1727 * @lock_key: lockdep class
1729 * This function closely associates a certain irqchip with a certain
1730 * gpiochip, providing an irq domain to translate the local IRQs to
1731 * global irqs in the gpiolib core, and making sure that the gpiochip
1732 * is passed as chip data to all related functions. Driver callbacks
1733 * need to use gpiochip_get_data() to get their local state containers back
1734 * from the gpiochip passed as chip data. An irqdomain will be stored
1735 * in the gpiochip that shall be used by the driver to handle IRQ number
1736 * translation. The gpiochip will need to be initialized and registered
1737 * before calling this function.
1739 * This function will handle two cell:ed simple IRQs and assumes all
1740 * the pins on the gpiochip can generate a unique IRQ. Everything else
1741 * need to be open coded.
1743 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
1744 struct irq_chip *irqchip,
1745 unsigned int first_irq,
1746 irq_flow_handler_t handler,
1749 struct lock_class_key *lock_key)
1751 struct device_node *of_node;
1752 bool irq_base_set = false;
1753 unsigned int offset;
1754 unsigned irq_base = 0;
1756 if (!gpiochip || !irqchip)
1759 if (!gpiochip->parent) {
1760 pr_err("missing gpiochip .dev parent pointer\n");
1763 gpiochip->irq_nested = nested;
1764 of_node = gpiochip->parent->of_node;
1765 #ifdef CONFIG_OF_GPIO
1767 * If the gpiochip has an assigned OF node this takes precedence
1768 * FIXME: get rid of this and use gpiochip->parent->of_node
1771 if (gpiochip->of_node)
1772 of_node = gpiochip->of_node;
1775 * Specifying a default trigger is a terrible idea if DT or ACPI is
1776 * used to configure the interrupts, as you may end-up with
1777 * conflicting triggers. Tell the user, and reset to NONE.
1779 if (WARN(of_node && type != IRQ_TYPE_NONE,
1780 "%s: Ignoring %d default trigger\n", of_node->full_name, type))
1781 type = IRQ_TYPE_NONE;
1782 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1783 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1784 "Ignoring %d default trigger\n", type);
1785 type = IRQ_TYPE_NONE;
1788 gpiochip->irqchip = irqchip;
1789 gpiochip->irq_handler = handler;
1790 gpiochip->irq_default_type = type;
1791 gpiochip->to_irq = gpiochip_to_irq;
1792 gpiochip->lock_key = lock_key;
1793 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1794 gpiochip->ngpio, first_irq,
1795 &gpiochip_domain_ops, gpiochip);
1796 if (!gpiochip->irqdomain) {
1797 gpiochip->irqchip = NULL;
1802 * It is possible for a driver to override this, but only if the
1803 * alternative functions are both implemented.
1805 if (!irqchip->irq_request_resources &&
1806 !irqchip->irq_release_resources) {
1807 irqchip->irq_request_resources = gpiochip_irq_reqres;
1808 irqchip->irq_release_resources = gpiochip_irq_relres;
1812 * Prepare the mapping since the irqchip shall be orthogonal to
1813 * any gpiochip calls. If the first_irq was zero, this is
1814 * necessary to allocate descriptors for all IRQs.
1816 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1817 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1819 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1820 if (!irq_base_set) {
1822 * Store the base into the gpiochip to be used when
1823 * unmapping the irqs.
1825 gpiochip->irq_base = irq_base;
1826 irq_base_set = true;
1830 acpi_gpiochip_request_interrupts(gpiochip);
1834 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
1836 #else /* CONFIG_GPIOLIB_IRQCHIP */
1838 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1839 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1843 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1846 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1849 * gpiochip_generic_request() - request the gpio function for a pin
1850 * @chip: the gpiochip owning the GPIO
1851 * @offset: the offset of the GPIO to request for GPIO function
1853 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1855 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1857 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1860 * gpiochip_generic_free() - free the gpio function from a pin
1861 * @chip: the gpiochip to request the gpio function for
1862 * @offset: the offset of the GPIO to free from GPIO function
1864 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1866 pinctrl_free_gpio(chip->gpiodev->base + offset);
1868 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1871 * gpiochip_generic_config() - apply configuration for a pin
1872 * @chip: the gpiochip owning the GPIO
1873 * @offset: the offset of the GPIO to apply the configuration
1874 * @config: the configuration to be applied
1876 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
1877 unsigned long config)
1879 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
1881 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1883 #ifdef CONFIG_PINCTRL
1886 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1887 * @chip: the gpiochip to add the range for
1888 * @pctldev: the pin controller to map to
1889 * @gpio_offset: the start offset in the current gpio_chip number space
1890 * @pin_group: name of the pin group inside the pin controller
1892 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1893 struct pinctrl_dev *pctldev,
1894 unsigned int gpio_offset, const char *pin_group)
1896 struct gpio_pin_range *pin_range;
1897 struct gpio_device *gdev = chip->gpiodev;
1900 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1902 chip_err(chip, "failed to allocate pin ranges\n");
1906 /* Use local offset as range ID */
1907 pin_range->range.id = gpio_offset;
1908 pin_range->range.gc = chip;
1909 pin_range->range.name = chip->label;
1910 pin_range->range.base = gdev->base + gpio_offset;
1911 pin_range->pctldev = pctldev;
1913 ret = pinctrl_get_group_pins(pctldev, pin_group,
1914 &pin_range->range.pins,
1915 &pin_range->range.npins);
1921 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1923 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1924 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1925 pinctrl_dev_get_devname(pctldev), pin_group);
1927 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1931 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1934 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1935 * @chip: the gpiochip to add the range for
1936 * @pinctrl_name: the dev_name() of the pin controller to map to
1937 * @gpio_offset: the start offset in the current gpio_chip number space
1938 * @pin_offset: the start offset in the pin controller number space
1939 * @npins: the number of pins from the offset of each pin space (GPIO and
1940 * pin controller) to accumulate in this range
1942 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1943 unsigned int gpio_offset, unsigned int pin_offset,
1946 struct gpio_pin_range *pin_range;
1947 struct gpio_device *gdev = chip->gpiodev;
1950 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1952 chip_err(chip, "failed to allocate pin ranges\n");
1956 /* Use local offset as range ID */
1957 pin_range->range.id = gpio_offset;
1958 pin_range->range.gc = chip;
1959 pin_range->range.name = chip->label;
1960 pin_range->range.base = gdev->base + gpio_offset;
1961 pin_range->range.pin_base = pin_offset;
1962 pin_range->range.npins = npins;
1963 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1965 if (IS_ERR(pin_range->pctldev)) {
1966 ret = PTR_ERR(pin_range->pctldev);
1967 chip_err(chip, "could not create pin range\n");
1971 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1972 gpio_offset, gpio_offset + npins - 1,
1974 pin_offset, pin_offset + npins - 1);
1976 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1980 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1983 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1984 * @chip: the chip to remove all the mappings for
1986 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1988 struct gpio_pin_range *pin_range, *tmp;
1989 struct gpio_device *gdev = chip->gpiodev;
1991 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1992 list_del(&pin_range->node);
1993 pinctrl_remove_gpio_range(pin_range->pctldev,
1998 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2000 #endif /* CONFIG_PINCTRL */
2002 /* These "optional" allocation calls help prevent drivers from stomping
2003 * on each other, and help provide better diagnostics in debugfs.
2004 * They're called even less than the "set direction" calls.
2006 static int __gpiod_request(struct gpio_desc *desc, const char *label)
2008 struct gpio_chip *chip = desc->gdev->chip;
2010 unsigned long flags;
2012 spin_lock_irqsave(&gpio_lock, flags);
2014 /* NOTE: gpio_request() can be called in early boot,
2015 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2018 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2019 desc_set_label(desc, label ? : "?");
2026 if (chip->request) {
2027 /* chip->request may sleep */
2028 spin_unlock_irqrestore(&gpio_lock, flags);
2029 status = chip->request(chip, gpio_chip_hwgpio(desc));
2030 spin_lock_irqsave(&gpio_lock, flags);
2033 desc_set_label(desc, NULL);
2034 clear_bit(FLAG_REQUESTED, &desc->flags);
2038 if (chip->get_direction) {
2039 /* chip->get_direction may sleep */
2040 spin_unlock_irqrestore(&gpio_lock, flags);
2041 gpiod_get_direction(desc);
2042 spin_lock_irqsave(&gpio_lock, flags);
2045 spin_unlock_irqrestore(&gpio_lock, flags);
2050 * This descriptor validation needs to be inserted verbatim into each
2051 * function taking a descriptor, so we need to use a preprocessor
2052 * macro to avoid endless duplication. If the desc is NULL it is an
2053 * optional GPIO and calls should just bail out.
2055 #define VALIDATE_DESC(desc) do { \
2058 if (IS_ERR(desc)) { \
2059 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2060 return PTR_ERR(desc); \
2062 if (!desc->gdev) { \
2063 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2066 if ( !desc->gdev->chip ) { \
2067 dev_warn(&desc->gdev->dev, \
2068 "%s: backing chip is gone\n", __func__); \
2072 #define VALIDATE_DESC_VOID(desc) do { \
2075 if (IS_ERR(desc)) { \
2076 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2079 if (!desc->gdev) { \
2080 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2083 if (!desc->gdev->chip) { \
2084 dev_warn(&desc->gdev->dev, \
2085 "%s: backing chip is gone\n", __func__); \
2090 int gpiod_request(struct gpio_desc *desc, const char *label)
2092 int status = -EPROBE_DEFER;
2093 struct gpio_device *gdev;
2095 VALIDATE_DESC(desc);
2098 if (try_module_get(gdev->owner)) {
2099 status = __gpiod_request(desc, label);
2101 module_put(gdev->owner);
2103 get_device(&gdev->dev);
2107 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2112 static bool __gpiod_free(struct gpio_desc *desc)
2115 unsigned long flags;
2116 struct gpio_chip *chip;
2120 gpiod_unexport(desc);
2122 spin_lock_irqsave(&gpio_lock, flags);
2124 chip = desc->gdev->chip;
2125 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2127 spin_unlock_irqrestore(&gpio_lock, flags);
2128 might_sleep_if(chip->can_sleep);
2129 chip->free(chip, gpio_chip_hwgpio(desc));
2130 spin_lock_irqsave(&gpio_lock, flags);
2132 desc_set_label(desc, NULL);
2133 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2134 clear_bit(FLAG_REQUESTED, &desc->flags);
2135 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2136 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2137 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2141 spin_unlock_irqrestore(&gpio_lock, flags);
2145 void gpiod_free(struct gpio_desc *desc)
2147 if (desc && desc->gdev && __gpiod_free(desc)) {
2148 module_put(desc->gdev->owner);
2149 put_device(&desc->gdev->dev);
2151 WARN_ON(extra_checks);
2156 * gpiochip_is_requested - return string iff signal was requested
2157 * @chip: controller managing the signal
2158 * @offset: of signal within controller's 0..(ngpio - 1) range
2160 * Returns NULL if the GPIO is not currently requested, else a string.
2161 * The string returned is the label passed to gpio_request(); if none has been
2162 * passed it is a meaningless, non-NULL constant.
2164 * This function is for use by GPIO controller drivers. The label can
2165 * help with diagnostics, and knowing that the signal is used as a GPIO
2166 * can help avoid accidentally multiplexing it to another controller.
2168 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2170 struct gpio_desc *desc;
2172 if (offset >= chip->ngpio)
2175 desc = &chip->gpiodev->descs[offset];
2177 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2181 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2184 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2185 * @desc: GPIO descriptor to request
2186 * @label: label for the GPIO
2188 * Function allows GPIO chip drivers to request and use their own GPIO
2189 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2190 * function will not increase reference count of the GPIO chip module. This
2191 * allows the GPIO chip module to be unloaded as needed (we assume that the
2192 * GPIO chip driver handles freeing the GPIOs it has requested).
2194 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2197 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2201 chip_err(chip, "failed to get GPIO descriptor\n");
2205 err = __gpiod_request(desc, label);
2207 return ERR_PTR(err);
2211 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2214 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2215 * @desc: GPIO descriptor to free
2217 * Function frees the given GPIO requested previously with
2218 * gpiochip_request_own_desc().
2220 void gpiochip_free_own_desc(struct gpio_desc *desc)
2225 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2228 * Drivers MUST set GPIO direction before making get/set calls. In
2229 * some cases this is done in early boot, before IRQs are enabled.
2231 * As a rule these aren't called more than once (except for drivers
2232 * using the open-drain emulation idiom) so these are natural places
2233 * to accumulate extra debugging checks. Note that we can't (yet)
2234 * rely on gpio_request() having been called beforehand.
2238 * gpiod_direction_input - set the GPIO direction to input
2239 * @desc: GPIO to set to input
2241 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2242 * be called safely on it.
2244 * Return 0 in case of success, else an error code.
2246 int gpiod_direction_input(struct gpio_desc *desc)
2248 struct gpio_chip *chip;
2249 int status = -EINVAL;
2251 VALIDATE_DESC(desc);
2252 chip = desc->gdev->chip;
2254 if (!chip->get || !chip->direction_input) {
2256 "%s: missing get() or direction_input() operations\n",
2261 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2263 clear_bit(FLAG_IS_OUT, &desc->flags);
2265 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2269 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2271 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2272 enum pin_config_param mode)
2274 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2276 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2279 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2281 struct gpio_chip *gc = desc->gdev->chip;
2285 /* GPIOs used for IRQs shall not be set as output */
2286 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2288 "%s: tried to set a GPIO tied to an IRQ as output\n",
2293 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2294 /* First see if we can enable open drain in hardware */
2295 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2296 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2298 goto set_output_value;
2299 /* Emulate open drain by not actively driving the line high */
2301 return gpiod_direction_input(desc);
2303 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2304 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2305 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2307 goto set_output_value;
2308 /* Emulate open source by not actively driving the line low */
2310 return gpiod_direction_input(desc);
2312 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2313 PIN_CONFIG_DRIVE_PUSH_PULL);
2317 if (!gc->set || !gc->direction_output) {
2319 "%s: missing set() or direction_output() operations\n",
2324 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2326 set_bit(FLAG_IS_OUT, &desc->flags);
2327 trace_gpio_value(desc_to_gpio(desc), 0, val);
2328 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2333 * gpiod_direction_output_raw - set the GPIO direction to output
2334 * @desc: GPIO to set to output
2335 * @value: initial output value of the GPIO
2337 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2338 * be called safely on it. The initial value of the output must be specified
2339 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2341 * Return 0 in case of success, else an error code.
2343 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2345 VALIDATE_DESC(desc);
2346 return _gpiod_direction_output_raw(desc, value);
2348 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2351 * gpiod_direction_output - set the GPIO direction to output
2352 * @desc: GPIO to set to output
2353 * @value: initial output value of the GPIO
2355 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2356 * be called safely on it. The initial value of the output must be specified
2357 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2360 * Return 0 in case of success, else an error code.
2362 int gpiod_direction_output(struct gpio_desc *desc, int value)
2364 VALIDATE_DESC(desc);
2365 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2369 return _gpiod_direction_output_raw(desc, value);
2371 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2374 * gpiod_set_debounce - sets @debounce time for a @gpio
2375 * @gpio: the gpio to set debounce time
2376 * @debounce: debounce time is microseconds
2378 * returns -ENOTSUPP if the controller does not support setting
2381 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2383 struct gpio_chip *chip;
2384 unsigned long config;
2386 VALIDATE_DESC(desc);
2387 chip = desc->gdev->chip;
2388 if (!chip->set || !chip->set_config) {
2390 "%s: missing set() or set_config() operations\n",
2395 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2396 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2398 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2401 * gpiod_is_active_low - test whether a GPIO is active-low or not
2402 * @desc: the gpio descriptor to test
2404 * Returns 1 if the GPIO is active-low, 0 otherwise.
2406 int gpiod_is_active_low(const struct gpio_desc *desc)
2408 VALIDATE_DESC(desc);
2409 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2411 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2413 /* I/O calls are only valid after configuration completed; the relevant
2414 * "is this a valid GPIO" error checks should already have been done.
2416 * "Get" operations are often inlinable as reading a pin value register,
2417 * and masking the relevant bit in that register.
2419 * When "set" operations are inlinable, they involve writing that mask to
2420 * one register to set a low value, or a different register to set it high.
2421 * Otherwise locking is needed, so there may be little value to inlining.
2423 *------------------------------------------------------------------------
2425 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2426 * have requested the GPIO. That can include implicit requesting by
2427 * a direction setting call. Marking a gpio as requested locks its chip
2428 * in memory, guaranteeing that these table lookups need no more locking
2429 * and that gpiochip_remove() will fail.
2431 * REVISIT when debugging, consider adding some instrumentation to ensure
2432 * that the GPIO was actually requested.
2435 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
2437 struct gpio_chip *chip;
2441 chip = desc->gdev->chip;
2442 offset = gpio_chip_hwgpio(desc);
2443 value = chip->get ? chip->get(chip, offset) : -EIO;
2444 value = value < 0 ? value : !!value;
2445 trace_gpio_value(desc_to_gpio(desc), 1, value);
2450 * gpiod_get_raw_value() - return a gpio's raw value
2451 * @desc: gpio whose value will be returned
2453 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2454 * its ACTIVE_LOW status, or negative errno on failure.
2456 * This function should be called from contexts where we cannot sleep, and will
2457 * complain if the GPIO chip functions potentially sleep.
2459 int gpiod_get_raw_value(const struct gpio_desc *desc)
2461 VALIDATE_DESC(desc);
2462 /* Should be using gpio_get_value_cansleep() */
2463 WARN_ON(desc->gdev->chip->can_sleep);
2464 return _gpiod_get_raw_value(desc);
2466 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2469 * gpiod_get_value() - return a gpio's value
2470 * @desc: gpio whose value will be returned
2472 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2473 * account, or negative errno on failure.
2475 * This function should be called from contexts where we cannot sleep, and will
2476 * complain if the GPIO chip functions potentially sleep.
2478 int gpiod_get_value(const struct gpio_desc *desc)
2482 VALIDATE_DESC(desc);
2483 /* Should be using gpio_get_value_cansleep() */
2484 WARN_ON(desc->gdev->chip->can_sleep);
2486 value = _gpiod_get_raw_value(desc);
2490 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2495 EXPORT_SYMBOL_GPL(gpiod_get_value);
2498 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2499 * @desc: gpio descriptor whose state need to be set.
2500 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2502 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2505 struct gpio_chip *chip = desc->gdev->chip;
2506 int offset = gpio_chip_hwgpio(desc);
2509 err = chip->direction_input(chip, offset);
2511 clear_bit(FLAG_IS_OUT, &desc->flags);
2513 err = chip->direction_output(chip, offset, 0);
2515 set_bit(FLAG_IS_OUT, &desc->flags);
2517 trace_gpio_direction(desc_to_gpio(desc), value, err);
2520 "%s: Error in set_value for open drain err %d\n",
2525 * _gpio_set_open_source_value() - Set the open source gpio's value.
2526 * @desc: gpio descriptor whose state need to be set.
2527 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2529 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2532 struct gpio_chip *chip = desc->gdev->chip;
2533 int offset = gpio_chip_hwgpio(desc);
2536 err = chip->direction_output(chip, offset, 1);
2538 set_bit(FLAG_IS_OUT, &desc->flags);
2540 err = chip->direction_input(chip, offset);
2542 clear_bit(FLAG_IS_OUT, &desc->flags);
2544 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2547 "%s: Error in set_value for open source err %d\n",
2551 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2553 struct gpio_chip *chip;
2555 chip = desc->gdev->chip;
2556 trace_gpio_value(desc_to_gpio(desc), 0, value);
2557 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2558 _gpio_set_open_drain_value(desc, value);
2559 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2560 _gpio_set_open_source_value(desc, value);
2562 chip->set(chip, gpio_chip_hwgpio(desc), value);
2566 * set multiple outputs on the same chip;
2567 * use the chip's set_multiple function if available;
2568 * otherwise set the outputs sequentially;
2569 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2570 * defines which outputs are to be changed
2571 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2572 * defines the values the outputs specified by mask are to be set to
2574 static void gpio_chip_set_multiple(struct gpio_chip *chip,
2575 unsigned long *mask, unsigned long *bits)
2577 if (chip->set_multiple) {
2578 chip->set_multiple(chip, mask, bits);
2582 /* set outputs if the corresponding mask bit is set */
2583 for_each_set_bit(i, mask, chip->ngpio)
2584 chip->set(chip, i, test_bit(i, bits));
2588 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2589 unsigned int array_size,
2590 struct gpio_desc **desc_array,
2595 while (i < array_size) {
2596 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2597 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2598 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2602 WARN_ON(chip->can_sleep);
2604 memset(mask, 0, sizeof(mask));
2606 struct gpio_desc *desc = desc_array[i];
2607 int hwgpio = gpio_chip_hwgpio(desc);
2608 int value = value_array[i];
2610 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2612 trace_gpio_value(desc_to_gpio(desc), 0, value);
2614 * collect all normal outputs belonging to the same chip
2615 * open drain and open source outputs are set individually
2617 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2618 _gpio_set_open_drain_value(desc, value);
2619 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2620 _gpio_set_open_source_value(desc, value);
2622 __set_bit(hwgpio, mask);
2624 __set_bit(hwgpio, bits);
2626 __clear_bit(hwgpio, bits);
2630 } while ((i < array_size) &&
2631 (desc_array[i]->gdev->chip == chip));
2632 /* push collected bits to outputs */
2634 gpio_chip_set_multiple(chip, mask, bits);
2639 * gpiod_set_raw_value() - assign a gpio's raw value
2640 * @desc: gpio whose value will be assigned
2641 * @value: value to assign
2643 * Set the raw value of the GPIO, i.e. the value of its physical line without
2644 * regard for its ACTIVE_LOW status.
2646 * This function should be called from contexts where we cannot sleep, and will
2647 * complain if the GPIO chip functions potentially sleep.
2649 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2651 VALIDATE_DESC_VOID(desc);
2652 /* Should be using gpiod_set_value_cansleep() */
2653 WARN_ON(desc->gdev->chip->can_sleep);
2654 _gpiod_set_raw_value(desc, value);
2656 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2659 * gpiod_set_value() - assign a gpio's value
2660 * @desc: gpio whose value will be assigned
2661 * @value: value to assign
2663 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2666 * This function should be called from contexts where we cannot sleep, and will
2667 * complain if the GPIO chip functions potentially sleep.
2669 void gpiod_set_value(struct gpio_desc *desc, int value)
2671 VALIDATE_DESC_VOID(desc);
2672 /* Should be using gpiod_set_value_cansleep() */
2673 WARN_ON(desc->gdev->chip->can_sleep);
2674 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2676 _gpiod_set_raw_value(desc, value);
2678 EXPORT_SYMBOL_GPL(gpiod_set_value);
2681 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2682 * @array_size: number of elements in the descriptor / value arrays
2683 * @desc_array: array of GPIO descriptors whose values will be assigned
2684 * @value_array: array of values to assign
2686 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2687 * without regard for their ACTIVE_LOW status.
2689 * This function should be called from contexts where we cannot sleep, and will
2690 * complain if the GPIO chip functions potentially sleep.
2692 void gpiod_set_raw_array_value(unsigned int array_size,
2693 struct gpio_desc **desc_array, int *value_array)
2697 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2700 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2703 * gpiod_set_array_value() - assign values to an array of GPIOs
2704 * @array_size: number of elements in the descriptor / value arrays
2705 * @desc_array: array of GPIO descriptors whose values will be assigned
2706 * @value_array: array of values to assign
2708 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2711 * This function should be called from contexts where we cannot sleep, and will
2712 * complain if the GPIO chip functions potentially sleep.
2714 void gpiod_set_array_value(unsigned int array_size,
2715 struct gpio_desc **desc_array, int *value_array)
2719 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2722 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2725 * gpiod_cansleep() - report whether gpio value access may sleep
2726 * @desc: gpio to check
2729 int gpiod_cansleep(const struct gpio_desc *desc)
2731 VALIDATE_DESC(desc);
2732 return desc->gdev->chip->can_sleep;
2734 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2737 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2738 * @desc: gpio whose IRQ will be returned (already requested)
2740 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2743 int gpiod_to_irq(const struct gpio_desc *desc)
2745 struct gpio_chip *chip;
2749 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2750 * requires this function to not return zero on an invalid descriptor
2751 * but rather a negative error number.
2753 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2756 chip = desc->gdev->chip;
2757 offset = gpio_chip_hwgpio(desc);
2759 int retirq = chip->to_irq(chip, offset);
2761 /* Zero means NO_IRQ */
2769 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2772 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2773 * @chip: the chip the GPIO to lock belongs to
2774 * @offset: the offset of the GPIO to lock as IRQ
2776 * This is used directly by GPIO drivers that want to lock down
2777 * a certain GPIO line to be used for IRQs.
2779 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2781 struct gpio_desc *desc;
2783 desc = gpiochip_get_desc(chip, offset);
2785 return PTR_ERR(desc);
2788 * If it's fast: flush the direction setting if something changed
2791 if (!chip->can_sleep && chip->get_direction) {
2792 int dir = chip->get_direction(chip, offset);
2795 clear_bit(FLAG_IS_OUT, &desc->flags);
2797 set_bit(FLAG_IS_OUT, &desc->flags);
2800 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2802 "%s: tried to flag a GPIO set as output for IRQ\n",
2807 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2810 * If the consumer has not set up a label (such as when the
2811 * IRQ is referenced from .to_irq()) we set up a label here
2812 * so it is clear this is used as an interrupt.
2815 desc_set_label(desc, "interrupt");
2819 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2822 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2823 * @chip: the chip the GPIO to lock belongs to
2824 * @offset: the offset of the GPIO to lock as IRQ
2826 * This is used directly by GPIO drivers that want to indicate
2827 * that a certain GPIO is no longer used exclusively for IRQ.
2829 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2831 struct gpio_desc *desc;
2833 desc = gpiochip_get_desc(chip, offset);
2837 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
2839 /* If we only had this marking, erase it */
2840 if (desc->label && !strcmp(desc->label, "interrupt"))
2841 desc_set_label(desc, NULL);
2843 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2845 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2847 if (offset >= chip->ngpio)
2850 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2852 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2854 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2856 if (offset >= chip->ngpio)
2859 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2861 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2863 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2865 if (offset >= chip->ngpio)
2868 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2870 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2873 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2874 * @desc: gpio whose value will be returned
2876 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2877 * its ACTIVE_LOW status, or negative errno on failure.
2879 * This function is to be called from contexts that can sleep.
2881 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2883 might_sleep_if(extra_checks);
2884 VALIDATE_DESC(desc);
2885 return _gpiod_get_raw_value(desc);
2887 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2890 * gpiod_get_value_cansleep() - return a gpio's value
2891 * @desc: gpio whose value will be returned
2893 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2894 * account, or negative errno on failure.
2896 * This function is to be called from contexts that can sleep.
2898 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2902 might_sleep_if(extra_checks);
2903 VALIDATE_DESC(desc);
2904 value = _gpiod_get_raw_value(desc);
2908 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2913 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2916 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2917 * @desc: gpio whose value will be assigned
2918 * @value: value to assign
2920 * Set the raw value of the GPIO, i.e. the value of its physical line without
2921 * regard for its ACTIVE_LOW status.
2923 * This function is to be called from contexts that can sleep.
2925 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2927 might_sleep_if(extra_checks);
2928 VALIDATE_DESC_VOID(desc);
2929 _gpiod_set_raw_value(desc, value);
2931 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2934 * gpiod_set_value_cansleep() - assign a gpio's value
2935 * @desc: gpio whose value will be assigned
2936 * @value: value to assign
2938 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2941 * This function is to be called from contexts that can sleep.
2943 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2945 might_sleep_if(extra_checks);
2946 VALIDATE_DESC_VOID(desc);
2947 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2949 _gpiod_set_raw_value(desc, value);
2951 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2954 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2955 * @array_size: number of elements in the descriptor / value arrays
2956 * @desc_array: array of GPIO descriptors whose values will be assigned
2957 * @value_array: array of values to assign
2959 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2960 * without regard for their ACTIVE_LOW status.
2962 * This function is to be called from contexts that can sleep.
2964 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2965 struct gpio_desc **desc_array,
2968 might_sleep_if(extra_checks);
2971 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2974 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2977 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2978 * @array_size: number of elements in the descriptor / value arrays
2979 * @desc_array: array of GPIO descriptors whose values will be assigned
2980 * @value_array: array of values to assign
2982 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2985 * This function is to be called from contexts that can sleep.
2987 void gpiod_set_array_value_cansleep(unsigned int array_size,
2988 struct gpio_desc **desc_array,
2991 might_sleep_if(extra_checks);
2994 gpiod_set_array_value_complex(false, true, array_size, desc_array,
2997 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3000 * gpiod_add_lookup_table() - register GPIO device consumers
3001 * @table: table of consumers to register
3003 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3005 mutex_lock(&gpio_lookup_lock);
3007 list_add_tail(&table->list, &gpio_lookup_list);
3009 mutex_unlock(&gpio_lookup_lock);
3013 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3014 * @table: table of consumers to unregister
3016 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3018 mutex_lock(&gpio_lookup_lock);
3020 list_del(&table->list);
3022 mutex_unlock(&gpio_lookup_lock);
3025 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3027 const char *dev_id = dev ? dev_name(dev) : NULL;
3028 struct gpiod_lookup_table *table;
3030 mutex_lock(&gpio_lookup_lock);
3032 list_for_each_entry(table, &gpio_lookup_list, list) {
3033 if (table->dev_id && dev_id) {
3035 * Valid strings on both ends, must be identical to have
3038 if (!strcmp(table->dev_id, dev_id))
3042 * One of the pointers is NULL, so both must be to have
3045 if (dev_id == table->dev_id)
3052 mutex_unlock(&gpio_lookup_lock);
3056 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3058 enum gpio_lookup_flags *flags)
3060 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3061 struct gpiod_lookup_table *table;
3062 struct gpiod_lookup *p;
3064 table = gpiod_find_lookup_table(dev);
3068 for (p = &table->table[0]; p->chip_label; p++) {
3069 struct gpio_chip *chip;
3071 /* idx must always match exactly */
3075 /* If the lookup entry has a con_id, require exact match */
3076 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3079 chip = find_chip_by_name(p->chip_label);
3082 dev_err(dev, "cannot find GPIO chip %s\n",
3084 return ERR_PTR(-ENODEV);
3087 if (chip->ngpio <= p->chip_hwnum) {
3089 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3090 idx, chip->ngpio, chip->label);
3091 return ERR_PTR(-EINVAL);
3094 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3103 static int dt_gpio_count(struct device *dev, const char *con_id)
3109 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3111 snprintf(propname, sizeof(propname), "%s-%s",
3112 con_id, gpio_suffixes[i]);
3114 snprintf(propname, sizeof(propname), "%s",
3117 ret = of_gpio_named_count(dev->of_node, propname);
3121 return ret ? ret : -ENOENT;
3124 static int platform_gpio_count(struct device *dev, const char *con_id)
3126 struct gpiod_lookup_table *table;
3127 struct gpiod_lookup *p;
3128 unsigned int count = 0;
3130 table = gpiod_find_lookup_table(dev);
3134 for (p = &table->table[0]; p->chip_label; p++) {
3135 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3136 (!con_id && !p->con_id))
3146 * gpiod_count - return the number of GPIOs associated with a device / function
3147 * or -ENOENT if no GPIO has been assigned to the requested function
3148 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3149 * @con_id: function within the GPIO consumer
3151 int gpiod_count(struct device *dev, const char *con_id)
3153 int count = -ENOENT;
3155 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3156 count = dt_gpio_count(dev, con_id);
3157 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3158 count = acpi_gpio_count(dev, con_id);
3161 count = platform_gpio_count(dev, con_id);
3165 EXPORT_SYMBOL_GPL(gpiod_count);
3168 * gpiod_get - obtain a GPIO for a given GPIO function
3169 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3170 * @con_id: function within the GPIO consumer
3171 * @flags: optional GPIO initialization flags
3173 * Return the GPIO descriptor corresponding to the function con_id of device
3174 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3175 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3177 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3178 enum gpiod_flags flags)
3180 return gpiod_get_index(dev, con_id, 0, flags);
3182 EXPORT_SYMBOL_GPL(gpiod_get);
3185 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3186 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3187 * @con_id: function within the GPIO consumer
3188 * @flags: optional GPIO initialization flags
3190 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3191 * the requested function it will return NULL. This is convenient for drivers
3192 * that need to handle optional GPIOs.
3194 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3196 enum gpiod_flags flags)
3198 return gpiod_get_index_optional(dev, con_id, 0, flags);
3200 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3204 * gpiod_configure_flags - helper function to configure a given GPIO
3205 * @desc: gpio whose value will be assigned
3206 * @con_id: function within the GPIO consumer
3207 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3209 * @dflags: gpiod_flags - optional GPIO initialization flags
3211 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3212 * requested function and/or index, or another IS_ERR() code if an error
3213 * occurred while trying to acquire the GPIO.
3215 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3216 unsigned long lflags, enum gpiod_flags dflags)
3220 if (lflags & GPIO_ACTIVE_LOW)
3221 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3222 if (lflags & GPIO_OPEN_DRAIN)
3223 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3224 if (lflags & GPIO_OPEN_SOURCE)
3225 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3227 /* No particular flag request, return here... */
3228 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3229 pr_debug("no flags found for %s\n", con_id);
3234 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3235 status = gpiod_direction_output(desc,
3236 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3238 status = gpiod_direction_input(desc);
3244 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3245 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3246 * @con_id: function within the GPIO consumer
3247 * @idx: index of the GPIO to obtain in the consumer
3248 * @flags: optional GPIO initialization flags
3250 * This variant of gpiod_get() allows to access GPIOs other than the first
3251 * defined one for functions that define several GPIOs.
3253 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3254 * requested function and/or index, or another IS_ERR() code if an error
3255 * occurred while trying to acquire the GPIO.
3257 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3260 enum gpiod_flags flags)
3262 struct gpio_desc *desc = NULL;
3264 enum gpio_lookup_flags lookupflags = 0;
3266 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3269 /* Using device tree? */
3270 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3271 dev_dbg(dev, "using device tree for GPIO lookup\n");
3272 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3273 } else if (ACPI_COMPANION(dev)) {
3274 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3275 desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
3280 * Either we are not using DT or ACPI, or their lookup did not return
3281 * a result. In that case, use platform lookup as a fallback.
3283 if (!desc || desc == ERR_PTR(-ENOENT)) {
3284 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3285 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3289 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
3293 status = gpiod_request(desc, con_id);
3295 return ERR_PTR(status);
3297 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3299 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3301 return ERR_PTR(status);
3306 EXPORT_SYMBOL_GPL(gpiod_get_index);
3309 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3310 * @fwnode: handle of the firmware node
3311 * @propname: name of the firmware property representing the GPIO
3312 * @index: index of the GPIO to obtain in the consumer
3313 * @dflags: GPIO initialization flags
3315 * This function can be used for drivers that get their configuration
3318 * Function properly finds the corresponding GPIO using whatever is the
3319 * underlying firmware interface and then makes sure that the GPIO
3320 * descriptor is requested before it is returned to the caller.
3322 * On successful request the GPIO pin is configured in accordance with
3325 * In case of error an ERR_PTR() is returned.
3327 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3328 const char *propname, int index,
3329 enum gpiod_flags dflags,
3332 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3333 unsigned long lflags = 0;
3334 bool active_low = false;
3335 bool single_ended = false;
3336 bool open_drain = false;
3340 return ERR_PTR(-EINVAL);
3342 if (is_of_node(fwnode)) {
3343 enum of_gpio_flags flags;
3345 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname,
3347 if (!IS_ERR(desc)) {
3348 active_low = flags & OF_GPIO_ACTIVE_LOW;
3349 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3350 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3352 } else if (is_acpi_node(fwnode)) {
3353 struct acpi_gpio_info info;
3355 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
3357 active_low = info.polarity == GPIO_ACTIVE_LOW;
3363 ret = gpiod_request(desc, label);
3365 return ERR_PTR(ret);
3368 lflags |= GPIO_ACTIVE_LOW;
3372 lflags |= GPIO_OPEN_DRAIN;
3374 lflags |= GPIO_OPEN_SOURCE;
3377 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3380 return ERR_PTR(ret);
3385 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3388 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3390 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3391 * @con_id: function within the GPIO consumer
3392 * @index: index of the GPIO to obtain in the consumer
3393 * @flags: optional GPIO initialization flags
3395 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3396 * specified index was assigned to the requested function it will return NULL.
3397 * This is convenient for drivers that need to handle optional GPIOs.
3399 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3402 enum gpiod_flags flags)
3404 struct gpio_desc *desc;
3406 desc = gpiod_get_index(dev, con_id, index, flags);
3408 if (PTR_ERR(desc) == -ENOENT)
3414 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3417 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3418 * @desc: gpio whose value will be assigned
3419 * @name: gpio line name
3420 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3422 * @dflags: gpiod_flags - optional GPIO initialization flags
3424 int gpiod_hog(struct gpio_desc *desc, const char *name,
3425 unsigned long lflags, enum gpiod_flags dflags)
3427 struct gpio_chip *chip;
3428 struct gpio_desc *local_desc;
3432 chip = gpiod_to_chip(desc);
3433 hwnum = gpio_chip_hwgpio(desc);
3435 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3436 if (IS_ERR(local_desc)) {
3437 status = PTR_ERR(local_desc);
3438 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3439 name, chip->label, hwnum, status);
3443 status = gpiod_configure_flags(desc, name, lflags, dflags);
3445 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3446 name, chip->label, hwnum, status);
3447 gpiochip_free_own_desc(desc);
3451 /* Mark GPIO as hogged so it can be identified and removed later */
3452 set_bit(FLAG_IS_HOGGED, &desc->flags);
3454 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3455 desc_to_gpio(desc), name,
3456 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3457 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3458 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3464 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3465 * @chip: gpio chip to act on
3467 * This is only used by of_gpiochip_remove to free hogged gpios
3469 static void gpiochip_free_hogs(struct gpio_chip *chip)
3473 for (id = 0; id < chip->ngpio; id++) {
3474 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3475 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3480 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3481 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3482 * @con_id: function within the GPIO consumer
3483 * @flags: optional GPIO initialization flags
3485 * This function acquires all the GPIOs defined under a given function.
3487 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3488 * no GPIO has been assigned to the requested function, or another IS_ERR()
3489 * code if an error occurred while trying to acquire the GPIOs.
3491 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
3493 enum gpiod_flags flags)
3495 struct gpio_desc *desc;
3496 struct gpio_descs *descs;
3499 count = gpiod_count(dev, con_id);
3501 return ERR_PTR(count);
3503 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
3506 return ERR_PTR(-ENOMEM);
3508 for (descs->ndescs = 0; descs->ndescs < count; ) {
3509 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
3511 gpiod_put_array(descs);
3512 return ERR_CAST(desc);
3514 descs->desc[descs->ndescs] = desc;
3519 EXPORT_SYMBOL_GPL(gpiod_get_array);
3522 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3524 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3525 * @con_id: function within the GPIO consumer
3526 * @flags: optional GPIO initialization flags
3528 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3529 * assigned to the requested function it will return NULL.
3531 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
3533 enum gpiod_flags flags)
3535 struct gpio_descs *descs;
3537 descs = gpiod_get_array(dev, con_id, flags);
3538 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
3543 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
3546 * gpiod_put - dispose of a GPIO descriptor
3547 * @desc: GPIO descriptor to dispose of
3549 * No descriptor can be used after gpiod_put() has been called on it.
3551 void gpiod_put(struct gpio_desc *desc)
3555 EXPORT_SYMBOL_GPL(gpiod_put);
3558 * gpiod_put_array - dispose of multiple GPIO descriptors
3559 * @descs: struct gpio_descs containing an array of descriptors
3561 void gpiod_put_array(struct gpio_descs *descs)
3565 for (i = 0; i < descs->ndescs; i++)
3566 gpiod_put(descs->desc[i]);
3570 EXPORT_SYMBOL_GPL(gpiod_put_array);
3572 static int __init gpiolib_dev_init(void)
3576 /* Register GPIO sysfs bus */
3577 ret = bus_register(&gpio_bus_type);
3579 pr_err("gpiolib: could not register GPIO bus type\n");
3583 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
3585 pr_err("gpiolib: failed to allocate char dev region\n");
3586 bus_unregister(&gpio_bus_type);
3588 gpiolib_initialized = true;
3589 gpiochip_setup_devs();
3593 core_initcall(gpiolib_dev_init);
3595 #ifdef CONFIG_DEBUG_FS
3597 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
3600 struct gpio_chip *chip = gdev->chip;
3601 unsigned gpio = gdev->base;
3602 struct gpio_desc *gdesc = &gdev->descs[0];
3606 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
3607 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
3609 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
3615 gpiod_get_direction(gdesc);
3616 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
3617 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
3618 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3619 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
3620 is_out ? "out" : "in ",
3622 ? (chip->get(chip, i) ? "hi" : "lo")
3624 is_irq ? "IRQ" : " ");
3625 seq_printf(s, "\n");
3629 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
3631 unsigned long flags;
3632 struct gpio_device *gdev = NULL;
3633 loff_t index = *pos;
3637 spin_lock_irqsave(&gpio_lock, flags);
3638 list_for_each_entry(gdev, &gpio_devices, list)
3640 spin_unlock_irqrestore(&gpio_lock, flags);
3643 spin_unlock_irqrestore(&gpio_lock, flags);
3648 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3650 unsigned long flags;
3651 struct gpio_device *gdev = v;
3654 spin_lock_irqsave(&gpio_lock, flags);
3655 if (list_is_last(&gdev->list, &gpio_devices))
3658 ret = list_entry(gdev->list.next, struct gpio_device, list);
3659 spin_unlock_irqrestore(&gpio_lock, flags);
3667 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3671 static int gpiolib_seq_show(struct seq_file *s, void *v)
3673 struct gpio_device *gdev = v;
3674 struct gpio_chip *chip = gdev->chip;
3675 struct device *parent;
3678 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3679 dev_name(&gdev->dev));
3683 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3684 dev_name(&gdev->dev),
3685 gdev->base, gdev->base + gdev->ngpio - 1);
3686 parent = chip->parent;
3688 seq_printf(s, ", parent: %s/%s",
3689 parent->bus ? parent->bus->name : "no-bus",
3692 seq_printf(s, ", %s", chip->label);
3693 if (chip->can_sleep)
3694 seq_printf(s, ", can sleep");
3695 seq_printf(s, ":\n");
3698 chip->dbg_show(s, chip);
3700 gpiolib_dbg_show(s, gdev);
3705 static const struct seq_operations gpiolib_seq_ops = {
3706 .start = gpiolib_seq_start,
3707 .next = gpiolib_seq_next,
3708 .stop = gpiolib_seq_stop,
3709 .show = gpiolib_seq_show,
3712 static int gpiolib_open(struct inode *inode, struct file *file)
3714 return seq_open(file, &gpiolib_seq_ops);
3717 static const struct file_operations gpiolib_operations = {
3718 .owner = THIS_MODULE,
3719 .open = gpiolib_open,
3721 .llseek = seq_lseek,
3722 .release = seq_release,
3725 static int __init gpiolib_debugfs_init(void)
3727 /* /sys/kernel/debug/gpio */
3728 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3729 NULL, NULL, &gpiolib_operations);
3732 subsys_initcall(gpiolib_debugfs_init);
3734 #endif /* DEBUG_FS */