1 #include <linux/bitmap.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_RISING_EDGE
712 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
713 int level = gpiod_get_value_cansleep(le->desc);
716 /* Emit low-to-high event */
717 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
719 /* Emit high-to-low event */
720 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
721 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
722 /* Emit low-to-high event */
723 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
724 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
725 /* Emit high-to-low event */
726 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
731 ret = kfifo_put(&le->events, ge);
733 wake_up_poll(&le->wait, POLLIN);
738 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
740 struct gpioevent_request eventreq;
741 struct lineevent_state *le;
742 struct gpio_desc *desc;
751 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
754 le = kzalloc(sizeof(*le), GFP_KERNEL);
758 get_device(&gdev->dev);
760 /* Make sure this is terminated */
761 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
762 if (strlen(eventreq.consumer_label)) {
763 le->label = kstrdup(eventreq.consumer_label,
771 offset = eventreq.lineoffset;
772 lflags = eventreq.handleflags;
773 eflags = eventreq.eventflags;
775 if (offset >= gdev->ngpio) {
780 /* Return an error if a unknown flag is set */
781 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
782 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
787 /* This is just wrong: we don't look for events on output lines */
788 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
793 desc = &gdev->descs[offset];
794 ret = gpiod_request(desc, le->label);
800 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
801 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
802 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
803 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
804 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
805 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
807 ret = gpiod_direction_input(desc);
811 le->irq = gpiod_to_irq(desc);
817 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
818 irqflags |= IRQF_TRIGGER_RISING;
819 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
820 irqflags |= IRQF_TRIGGER_FALLING;
821 irqflags |= IRQF_ONESHOT;
822 irqflags |= IRQF_SHARED;
824 INIT_KFIFO(le->events);
825 init_waitqueue_head(&le->wait);
826 mutex_init(&le->read_lock);
828 /* Request a thread to read the events */
829 ret = request_threaded_irq(le->irq,
831 lineevent_irq_thread,
838 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
844 file = anon_inode_getfile("gpio-event",
847 O_RDONLY | O_CLOEXEC);
850 goto out_put_unused_fd;
854 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
856 * fput() will trigger the release() callback, so do not go onto
857 * the regular error cleanup path here.
864 fd_install(fd, file);
871 free_irq(le->irq, le);
873 gpiod_free(le->desc);
878 put_device(&gdev->dev);
883 * gpio_ioctl() - ioctl handler for the GPIO chardev
885 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
887 struct gpio_device *gdev = filp->private_data;
888 struct gpio_chip *chip = gdev->chip;
889 void __user *ip = (void __user *)arg;
891 /* We fail any subsequent ioctl():s when the chip is gone */
895 /* Fill in the struct and pass to userspace */
896 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
897 struct gpiochip_info chipinfo;
899 memset(&chipinfo, 0, sizeof(chipinfo));
901 strncpy(chipinfo.name, dev_name(&gdev->dev),
902 sizeof(chipinfo.name));
903 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
904 strncpy(chipinfo.label, gdev->label,
905 sizeof(chipinfo.label));
906 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
907 chipinfo.lines = gdev->ngpio;
908 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
911 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
912 struct gpioline_info lineinfo;
913 struct gpio_desc *desc;
915 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
917 if (lineinfo.line_offset >= gdev->ngpio)
920 desc = &gdev->descs[lineinfo.line_offset];
922 strncpy(lineinfo.name, desc->name,
923 sizeof(lineinfo.name));
924 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
926 lineinfo.name[0] = '\0';
929 strncpy(lineinfo.consumer, desc->label,
930 sizeof(lineinfo.consumer));
931 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
933 lineinfo.consumer[0] = '\0';
937 * Userspace only need to know that the kernel is using
938 * this GPIO so it can't use it.
941 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
942 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
943 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
944 test_bit(FLAG_EXPORT, &desc->flags) ||
945 test_bit(FLAG_SYSFS, &desc->flags))
946 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
947 if (test_bit(FLAG_IS_OUT, &desc->flags))
948 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
949 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
950 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
951 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
952 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
953 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
954 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
956 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
959 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
960 return linehandle_create(gdev, ip);
961 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
962 return lineevent_create(gdev, ip);
968 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
971 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
976 * gpio_chrdev_open() - open the chardev for ioctl operations
977 * @inode: inode for this chardev
978 * @filp: file struct for storing private data
979 * Returns 0 on success
981 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
983 struct gpio_device *gdev = container_of(inode->i_cdev,
984 struct gpio_device, chrdev);
986 /* Fail on open if the backing gpiochip is gone */
989 get_device(&gdev->dev);
990 filp->private_data = gdev;
992 return nonseekable_open(inode, filp);
996 * gpio_chrdev_release() - close chardev after ioctl operations
997 * @inode: inode for this chardev
998 * @filp: file struct for storing private data
999 * Returns 0 on success
1001 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1003 struct gpio_device *gdev = container_of(inode->i_cdev,
1004 struct gpio_device, chrdev);
1006 put_device(&gdev->dev);
1011 static const struct file_operations gpio_fileops = {
1012 .release = gpio_chrdev_release,
1013 .open = gpio_chrdev_open,
1014 .owner = THIS_MODULE,
1015 .llseek = no_llseek,
1016 .unlocked_ioctl = gpio_ioctl,
1017 #ifdef CONFIG_COMPAT
1018 .compat_ioctl = gpio_ioctl_compat,
1022 static void gpiodevice_release(struct device *dev)
1024 struct gpio_device *gdev = dev_get_drvdata(dev);
1026 list_del(&gdev->list);
1027 ida_simple_remove(&gpio_ida, gdev->id);
1033 static int gpiochip_setup_dev(struct gpio_device *gdev)
1037 cdev_init(&gdev->chrdev, &gpio_fileops);
1038 gdev->chrdev.owner = THIS_MODULE;
1039 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1041 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1045 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1046 MAJOR(gpio_devt), gdev->id);
1048 status = gpiochip_sysfs_register(gdev);
1050 goto err_remove_device;
1052 /* From this point, the .release() function cleans up gpio_device */
1053 gdev->dev.release = gpiodevice_release;
1054 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1055 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1056 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1061 cdev_device_del(&gdev->chrdev, &gdev->dev);
1065 static void gpiochip_setup_devs(void)
1067 struct gpio_device *gdev;
1070 list_for_each_entry(gdev, &gpio_devices, list) {
1071 err = gpiochip_setup_dev(gdev);
1073 pr_err("%s: Failed to initialize gpio device (%d)\n",
1074 dev_name(&gdev->dev), err);
1079 * gpiochip_add_data() - register a gpio_chip
1080 * @chip: the chip to register, with chip->base initialized
1081 * Context: potentially before irqs will work
1083 * Returns a negative errno if the chip can't be registered, such as
1084 * because the chip->base is invalid or already associated with a
1085 * different chip. Otherwise it returns zero as a success code.
1087 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1088 * can be freely used, the chip->parent device must be registered before
1089 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1090 * for GPIOs will fail rudely.
1092 * gpiochip_add_data() must only be called after gpiolib initialization,
1093 * ie after core_initcall().
1095 * If chip->base is negative, this requests dynamic assignment of
1096 * a range of valid GPIOs.
1098 int gpiochip_add_data(struct gpio_chip *chip, void *data)
1100 unsigned long flags;
1103 int base = chip->base;
1104 struct gpio_device *gdev;
1107 * First: allocate and populate the internal stat container, and
1108 * set up the struct device.
1110 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1113 gdev->dev.bus = &gpio_bus_type;
1115 chip->gpiodev = gdev;
1117 gdev->dev.parent = chip->parent;
1118 gdev->dev.of_node = chip->parent->of_node;
1121 #ifdef CONFIG_OF_GPIO
1122 /* If the gpiochip has an assigned OF node this takes precedence */
1124 gdev->dev.of_node = chip->of_node;
1127 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1132 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1133 device_initialize(&gdev->dev);
1134 dev_set_drvdata(&gdev->dev, gdev);
1135 if (chip->parent && chip->parent->driver)
1136 gdev->owner = chip->parent->driver->owner;
1137 else if (chip->owner)
1138 /* TODO: remove chip->owner */
1139 gdev->owner = chip->owner;
1141 gdev->owner = THIS_MODULE;
1143 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1149 if (chip->ngpio == 0) {
1150 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1152 goto err_free_descs;
1156 gdev->label = kstrdup(chip->label, GFP_KERNEL);
1158 gdev->label = kstrdup("unknown", GFP_KERNEL);
1161 goto err_free_descs;
1164 gdev->ngpio = chip->ngpio;
1167 spin_lock_irqsave(&gpio_lock, flags);
1170 * TODO: this allocates a Linux GPIO number base in the global
1171 * GPIO numberspace for this chip. In the long run we want to
1172 * get *rid* of this numberspace and use only descriptors, but
1173 * it may be a pipe dream. It will not happen before we get rid
1174 * of the sysfs interface anyways.
1177 base = gpiochip_find_base(chip->ngpio);
1180 spin_unlock_irqrestore(&gpio_lock, flags);
1181 goto err_free_label;
1184 * TODO: it should not be necessary to reflect the assigned
1185 * base outside of the GPIO subsystem. Go over drivers and
1186 * see if anyone makes use of this, else drop this and assign
1193 status = gpiodev_add_to_list(gdev);
1195 spin_unlock_irqrestore(&gpio_lock, flags);
1196 goto err_free_label;
1199 spin_unlock_irqrestore(&gpio_lock, flags);
1201 for (i = 0; i < chip->ngpio; i++) {
1202 struct gpio_desc *desc = &gdev->descs[i];
1206 * REVISIT: most hardware initializes GPIOs as inputs
1207 * (often with pullups enabled) so power usage is
1208 * minimized. Linux code should set the gpio direction
1209 * first thing; but until it does, and in case
1210 * chip->get_direction is not set, we may expose the
1211 * wrong direction in sysfs.
1214 if (chip->get_direction) {
1216 * If we have .get_direction, set up the initial
1217 * direction flag from the hardware.
1219 int dir = chip->get_direction(chip, i);
1222 set_bit(FLAG_IS_OUT, &desc->flags);
1223 } else if (!chip->direction_input) {
1225 * If the chip lacks the .direction_input callback
1226 * we logically assume all lines are outputs.
1228 set_bit(FLAG_IS_OUT, &desc->flags);
1232 #ifdef CONFIG_PINCTRL
1233 INIT_LIST_HEAD(&gdev->pin_ranges);
1236 status = gpiochip_set_desc_names(chip);
1238 goto err_remove_from_list;
1240 status = gpiochip_irqchip_init_valid_mask(chip);
1242 goto err_remove_from_list;
1244 status = of_gpiochip_add(chip);
1246 goto err_remove_chip;
1248 acpi_gpiochip_add(chip);
1251 * By first adding the chardev, and then adding the device,
1252 * we get a device node entry in sysfs under
1253 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1254 * coldplug of device nodes and other udev business.
1255 * We can do this only if gpiolib has been initialized.
1256 * Otherwise, defer until later.
1258 if (gpiolib_initialized) {
1259 status = gpiochip_setup_dev(gdev);
1261 goto err_remove_chip;
1266 acpi_gpiochip_remove(chip);
1267 gpiochip_free_hogs(chip);
1268 of_gpiochip_remove(chip);
1269 gpiochip_irqchip_free_valid_mask(chip);
1270 err_remove_from_list:
1271 spin_lock_irqsave(&gpio_lock, flags);
1272 list_del(&gdev->list);
1273 spin_unlock_irqrestore(&gpio_lock, flags);
1279 ida_simple_remove(&gpio_ida, gdev->id);
1280 /* failures here can mean systems won't boot... */
1281 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1282 gdev->base, gdev->base + gdev->ngpio - 1,
1283 chip->label ? : "generic");
1287 EXPORT_SYMBOL_GPL(gpiochip_add_data);
1290 * gpiochip_get_data() - get per-subdriver data for the chip
1292 void *gpiochip_get_data(struct gpio_chip *chip)
1294 return chip->gpiodev->data;
1296 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1299 * gpiochip_remove() - unregister a gpio_chip
1300 * @chip: the chip to unregister
1302 * A gpio_chip with any GPIOs still requested may not be removed.
1304 void gpiochip_remove(struct gpio_chip *chip)
1306 struct gpio_device *gdev = chip->gpiodev;
1307 struct gpio_desc *desc;
1308 unsigned long flags;
1310 bool requested = false;
1312 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1313 gpiochip_sysfs_unregister(gdev);
1314 gpiochip_free_hogs(chip);
1315 /* Numb the device, cancelling all outstanding operations */
1317 gpiochip_irqchip_remove(chip);
1318 acpi_gpiochip_remove(chip);
1319 gpiochip_remove_pin_ranges(chip);
1320 of_gpiochip_remove(chip);
1322 * We accept no more calls into the driver from this point, so
1323 * NULL the driver data pointer
1327 spin_lock_irqsave(&gpio_lock, flags);
1328 for (i = 0; i < gdev->ngpio; i++) {
1329 desc = &gdev->descs[i];
1330 if (test_bit(FLAG_REQUESTED, &desc->flags))
1333 spin_unlock_irqrestore(&gpio_lock, flags);
1336 dev_crit(&gdev->dev,
1337 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1340 * The gpiochip side puts its use of the device to rest here:
1341 * if there are no userspace clients, the chardev and device will
1342 * be removed, else it will be dangling until the last user is
1345 cdev_device_del(&gdev->chrdev, &gdev->dev);
1346 put_device(&gdev->dev);
1348 EXPORT_SYMBOL_GPL(gpiochip_remove);
1350 static void devm_gpio_chip_release(struct device *dev, void *res)
1352 struct gpio_chip *chip = *(struct gpio_chip **)res;
1354 gpiochip_remove(chip);
1357 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1360 struct gpio_chip **r = res;
1371 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1372 * @dev: the device pointer on which irq_chip belongs to.
1373 * @chip: the chip to register, with chip->base initialized
1374 * Context: potentially before irqs will work
1376 * Returns a negative errno if the chip can't be registered, such as
1377 * because the chip->base is invalid or already associated with a
1378 * different chip. Otherwise it returns zero as a success code.
1380 * The gpio chip automatically be released when the device is unbound.
1382 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1385 struct gpio_chip **ptr;
1388 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1393 ret = gpiochip_add_data(chip, data);
1400 devres_add(dev, ptr);
1404 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1407 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1408 * @dev: device for which which resource was allocated
1409 * @chip: the chip to remove
1411 * A gpio_chip with any GPIOs still requested may not be removed.
1413 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1417 ret = devres_release(dev, devm_gpio_chip_release,
1418 devm_gpio_chip_match, chip);
1421 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1424 * gpiochip_find() - iterator for locating a specific gpio_chip
1425 * @data: data to pass to match function
1426 * @callback: Callback function to check gpio_chip
1428 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1429 * determined by a user supplied @match callback. The callback should return
1430 * 0 if the device doesn't match and non-zero if it does. If the callback is
1431 * non-zero, this function will return to the caller and not iterate over any
1434 struct gpio_chip *gpiochip_find(void *data,
1435 int (*match)(struct gpio_chip *chip,
1438 struct gpio_device *gdev;
1439 struct gpio_chip *chip = NULL;
1440 unsigned long flags;
1442 spin_lock_irqsave(&gpio_lock, flags);
1443 list_for_each_entry(gdev, &gpio_devices, list)
1444 if (gdev->chip && match(gdev->chip, data)) {
1449 spin_unlock_irqrestore(&gpio_lock, flags);
1453 EXPORT_SYMBOL_GPL(gpiochip_find);
1455 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1457 const char *name = data;
1459 return !strcmp(chip->label, name);
1462 static struct gpio_chip *find_chip_by_name(const char *name)
1464 return gpiochip_find((void *)name, gpiochip_match_name);
1467 #ifdef CONFIG_GPIOLIB_IRQCHIP
1470 * The following is irqchip helper code for gpiochips.
1473 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1475 if (!gpiochip->irq_need_valid_mask)
1478 gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
1479 sizeof(long), GFP_KERNEL);
1480 if (!gpiochip->irq_valid_mask)
1483 /* Assume by default all GPIOs are valid */
1484 bitmap_fill(gpiochip->irq_valid_mask, gpiochip->ngpio);
1489 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1491 kfree(gpiochip->irq_valid_mask);
1492 gpiochip->irq_valid_mask = NULL;
1495 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1496 unsigned int offset)
1498 /* No mask means all valid */
1499 if (likely(!gpiochip->irq_valid_mask))
1501 return test_bit(offset, gpiochip->irq_valid_mask);
1505 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1506 * @gpiochip: the gpiochip to set the irqchip chain to
1507 * @irqchip: the irqchip to chain to the gpiochip
1508 * @parent_irq: the irq number corresponding to the parent IRQ for this
1510 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1511 * coming out of the gpiochip. If the interrupt is nested rather than
1512 * cascaded, pass NULL in this handler argument
1514 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1515 struct irq_chip *irqchip,
1516 unsigned int parent_irq,
1517 irq_flow_handler_t parent_handler)
1519 unsigned int offset;
1521 if (!gpiochip->irqdomain) {
1522 chip_err(gpiochip, "called %s before setting up irqchip\n",
1527 if (parent_handler) {
1528 if (gpiochip->can_sleep) {
1530 "you cannot have chained interrupts on a "
1531 "chip that may sleep\n");
1535 * The parent irqchip is already using the chip_data for this
1536 * irqchip, so our callbacks simply use the handler_data.
1538 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1541 gpiochip->irq_chained_parent = parent_irq;
1544 /* Set the parent IRQ for all affected IRQs */
1545 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1546 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1548 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
1554 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1555 * @gpiochip: the gpiochip to set the irqchip chain to
1556 * @irqchip: the irqchip to chain to the gpiochip
1557 * @parent_irq: the irq number corresponding to the parent IRQ for this
1559 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1560 * coming out of the gpiochip. If the interrupt is nested rather than
1561 * cascaded, pass NULL in this handler argument
1563 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1564 struct irq_chip *irqchip,
1565 unsigned int parent_irq,
1566 irq_flow_handler_t parent_handler)
1568 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1571 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1574 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1575 * @gpiochip: the gpiochip to set the irqchip nested handler to
1576 * @irqchip: the irqchip to nest to the gpiochip
1577 * @parent_irq: the irq number corresponding to the parent IRQ for this
1580 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1581 struct irq_chip *irqchip,
1582 unsigned int parent_irq)
1584 if (!gpiochip->irq_nested) {
1585 chip_err(gpiochip, "tried to nest a chained gpiochip\n");
1588 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1591 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1594 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1595 * @d: the irqdomain used by this irqchip
1596 * @irq: the global irq number used by this GPIO irqchip irq
1597 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1599 * This function will set up the mapping for a certain IRQ line on a
1600 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1601 * stored inside the gpiochip.
1603 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1604 irq_hw_number_t hwirq)
1606 struct gpio_chip *chip = d->host_data;
1608 irq_set_chip_data(irq, chip);
1610 * This lock class tells lockdep that GPIO irqs are in a different
1611 * category than their parents, so it won't report false recursion.
1613 irq_set_lockdep_class(irq, chip->lock_key);
1614 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1615 /* Chips that use nested thread handlers have them marked */
1616 if (chip->irq_nested)
1617 irq_set_nested_thread(irq, 1);
1618 irq_set_noprobe(irq);
1621 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1622 * is passed as default type.
1624 if (chip->irq_default_type != IRQ_TYPE_NONE)
1625 irq_set_irq_type(irq, chip->irq_default_type);
1630 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1632 struct gpio_chip *chip = d->host_data;
1634 if (chip->irq_nested)
1635 irq_set_nested_thread(irq, 0);
1636 irq_set_chip_and_handler(irq, NULL, NULL);
1637 irq_set_chip_data(irq, NULL);
1640 static const struct irq_domain_ops gpiochip_domain_ops = {
1641 .map = gpiochip_irq_map,
1642 .unmap = gpiochip_irq_unmap,
1643 /* Virtually all GPIO irqchips are twocell:ed */
1644 .xlate = irq_domain_xlate_twocell,
1647 static int gpiochip_irq_reqres(struct irq_data *d)
1649 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1651 if (!try_module_get(chip->gpiodev->owner))
1654 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1656 "unable to lock HW IRQ %lu for IRQ\n",
1658 module_put(chip->gpiodev->owner);
1664 static void gpiochip_irq_relres(struct irq_data *d)
1666 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1668 gpiochip_unlock_as_irq(chip, d->hwirq);
1669 module_put(chip->gpiodev->owner);
1672 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1674 return irq_find_mapping(chip->irqdomain, offset);
1678 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1679 * @gpiochip: the gpiochip to remove the irqchip from
1681 * This is called only from gpiochip_remove()
1683 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1685 unsigned int offset;
1687 acpi_gpiochip_free_interrupts(gpiochip);
1689 if (gpiochip->irq_chained_parent) {
1690 irq_set_chained_handler(gpiochip->irq_chained_parent, NULL);
1691 irq_set_handler_data(gpiochip->irq_chained_parent, NULL);
1694 /* Remove all IRQ mappings and delete the domain */
1695 if (gpiochip->irqdomain) {
1696 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1697 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1699 irq_dispose_mapping(
1700 irq_find_mapping(gpiochip->irqdomain, offset));
1702 irq_domain_remove(gpiochip->irqdomain);
1705 if (gpiochip->irqchip) {
1706 gpiochip->irqchip->irq_request_resources = NULL;
1707 gpiochip->irqchip->irq_release_resources = NULL;
1708 gpiochip->irqchip = NULL;
1711 gpiochip_irqchip_free_valid_mask(gpiochip);
1715 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1716 * @gpiochip: the gpiochip to add the irqchip to
1717 * @irqchip: the irqchip to add to the gpiochip
1718 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1719 * allocate gpiochip irqs from
1720 * @handler: the irq handler to use (often a predefined irq core function)
1721 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1722 * to have the core avoid setting up any default type in the hardware.
1723 * @nested: whether this is a nested irqchip calling handle_nested_irq()
1724 * in its IRQ handler
1725 * @lock_key: lockdep class
1727 * This function closely associates a certain irqchip with a certain
1728 * gpiochip, providing an irq domain to translate the local IRQs to
1729 * global irqs in the gpiolib core, and making sure that the gpiochip
1730 * is passed as chip data to all related functions. Driver callbacks
1731 * need to use gpiochip_get_data() to get their local state containers back
1732 * from the gpiochip passed as chip data. An irqdomain will be stored
1733 * in the gpiochip that shall be used by the driver to handle IRQ number
1734 * translation. The gpiochip will need to be initialized and registered
1735 * before calling this function.
1737 * This function will handle two cell:ed simple IRQs and assumes all
1738 * the pins on the gpiochip can generate a unique IRQ. Everything else
1739 * need to be open coded.
1741 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
1742 struct irq_chip *irqchip,
1743 unsigned int first_irq,
1744 irq_flow_handler_t handler,
1747 struct lock_class_key *lock_key)
1749 struct device_node *of_node;
1750 bool irq_base_set = false;
1751 unsigned int offset;
1752 unsigned irq_base = 0;
1754 if (!gpiochip || !irqchip)
1757 if (!gpiochip->parent) {
1758 pr_err("missing gpiochip .dev parent pointer\n");
1761 gpiochip->irq_nested = nested;
1762 of_node = gpiochip->parent->of_node;
1763 #ifdef CONFIG_OF_GPIO
1765 * If the gpiochip has an assigned OF node this takes precedence
1766 * FIXME: get rid of this and use gpiochip->parent->of_node
1769 if (gpiochip->of_node)
1770 of_node = gpiochip->of_node;
1773 * Specifying a default trigger is a terrible idea if DT or ACPI is
1774 * used to configure the interrupts, as you may end-up with
1775 * conflicting triggers. Tell the user, and reset to NONE.
1777 if (WARN(of_node && type != IRQ_TYPE_NONE,
1778 "%s: Ignoring %d default trigger\n", of_node->full_name, type))
1779 type = IRQ_TYPE_NONE;
1780 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1781 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1782 "Ignoring %d default trigger\n", type);
1783 type = IRQ_TYPE_NONE;
1786 gpiochip->irqchip = irqchip;
1787 gpiochip->irq_handler = handler;
1788 gpiochip->irq_default_type = type;
1789 gpiochip->to_irq = gpiochip_to_irq;
1790 gpiochip->lock_key = lock_key;
1791 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1792 gpiochip->ngpio, first_irq,
1793 &gpiochip_domain_ops, gpiochip);
1794 if (!gpiochip->irqdomain) {
1795 gpiochip->irqchip = NULL;
1800 * It is possible for a driver to override this, but only if the
1801 * alternative functions are both implemented.
1803 if (!irqchip->irq_request_resources &&
1804 !irqchip->irq_release_resources) {
1805 irqchip->irq_request_resources = gpiochip_irq_reqres;
1806 irqchip->irq_release_resources = gpiochip_irq_relres;
1810 * Prepare the mapping since the irqchip shall be orthogonal to
1811 * any gpiochip calls. If the first_irq was zero, this is
1812 * necessary to allocate descriptors for all IRQs.
1814 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1815 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1817 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1818 if (!irq_base_set) {
1820 * Store the base into the gpiochip to be used when
1821 * unmapping the irqs.
1823 gpiochip->irq_base = irq_base;
1824 irq_base_set = true;
1828 acpi_gpiochip_request_interrupts(gpiochip);
1832 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
1834 #else /* CONFIG_GPIOLIB_IRQCHIP */
1836 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1837 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1841 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1844 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1847 * gpiochip_generic_request() - request the gpio function for a pin
1848 * @chip: the gpiochip owning the GPIO
1849 * @offset: the offset of the GPIO to request for GPIO function
1851 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1853 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1855 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1858 * gpiochip_generic_free() - free the gpio function from a pin
1859 * @chip: the gpiochip to request the gpio function for
1860 * @offset: the offset of the GPIO to free from GPIO function
1862 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1864 pinctrl_free_gpio(chip->gpiodev->base + offset);
1866 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1869 * gpiochip_generic_config() - apply configuration for a pin
1870 * @chip: the gpiochip owning the GPIO
1871 * @offset: the offset of the GPIO to apply the configuration
1872 * @config: the configuration to be applied
1874 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
1875 unsigned long config)
1877 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
1879 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1881 #ifdef CONFIG_PINCTRL
1884 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1885 * @chip: the gpiochip to add the range for
1886 * @pctldev: the pin controller to map to
1887 * @gpio_offset: the start offset in the current gpio_chip number space
1888 * @pin_group: name of the pin group inside the pin controller
1890 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1891 struct pinctrl_dev *pctldev,
1892 unsigned int gpio_offset, const char *pin_group)
1894 struct gpio_pin_range *pin_range;
1895 struct gpio_device *gdev = chip->gpiodev;
1898 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1900 chip_err(chip, "failed to allocate pin ranges\n");
1904 /* Use local offset as range ID */
1905 pin_range->range.id = gpio_offset;
1906 pin_range->range.gc = chip;
1907 pin_range->range.name = chip->label;
1908 pin_range->range.base = gdev->base + gpio_offset;
1909 pin_range->pctldev = pctldev;
1911 ret = pinctrl_get_group_pins(pctldev, pin_group,
1912 &pin_range->range.pins,
1913 &pin_range->range.npins);
1919 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1921 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1922 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1923 pinctrl_dev_get_devname(pctldev), pin_group);
1925 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1929 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1932 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1933 * @chip: the gpiochip to add the range for
1934 * @pinctrl_name: the dev_name() of the pin controller to map to
1935 * @gpio_offset: the start offset in the current gpio_chip number space
1936 * @pin_offset: the start offset in the pin controller number space
1937 * @npins: the number of pins from the offset of each pin space (GPIO and
1938 * pin controller) to accumulate in this range
1940 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1941 unsigned int gpio_offset, unsigned int pin_offset,
1944 struct gpio_pin_range *pin_range;
1945 struct gpio_device *gdev = chip->gpiodev;
1948 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1950 chip_err(chip, "failed to allocate pin ranges\n");
1954 /* Use local offset as range ID */
1955 pin_range->range.id = gpio_offset;
1956 pin_range->range.gc = chip;
1957 pin_range->range.name = chip->label;
1958 pin_range->range.base = gdev->base + gpio_offset;
1959 pin_range->range.pin_base = pin_offset;
1960 pin_range->range.npins = npins;
1961 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1963 if (IS_ERR(pin_range->pctldev)) {
1964 ret = PTR_ERR(pin_range->pctldev);
1965 chip_err(chip, "could not create pin range\n");
1969 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1970 gpio_offset, gpio_offset + npins - 1,
1972 pin_offset, pin_offset + npins - 1);
1974 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1978 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1981 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1982 * @chip: the chip to remove all the mappings for
1984 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1986 struct gpio_pin_range *pin_range, *tmp;
1987 struct gpio_device *gdev = chip->gpiodev;
1989 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1990 list_del(&pin_range->node);
1991 pinctrl_remove_gpio_range(pin_range->pctldev,
1996 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1998 #endif /* CONFIG_PINCTRL */
2000 /* These "optional" allocation calls help prevent drivers from stomping
2001 * on each other, and help provide better diagnostics in debugfs.
2002 * They're called even less than the "set direction" calls.
2004 static int __gpiod_request(struct gpio_desc *desc, const char *label)
2006 struct gpio_chip *chip = desc->gdev->chip;
2008 unsigned long flags;
2010 spin_lock_irqsave(&gpio_lock, flags);
2012 /* NOTE: gpio_request() can be called in early boot,
2013 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2016 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2017 desc_set_label(desc, label ? : "?");
2024 if (chip->request) {
2025 /* chip->request may sleep */
2026 spin_unlock_irqrestore(&gpio_lock, flags);
2027 status = chip->request(chip, gpio_chip_hwgpio(desc));
2028 spin_lock_irqsave(&gpio_lock, flags);
2031 desc_set_label(desc, NULL);
2032 clear_bit(FLAG_REQUESTED, &desc->flags);
2036 if (chip->get_direction) {
2037 /* chip->get_direction may sleep */
2038 spin_unlock_irqrestore(&gpio_lock, flags);
2039 gpiod_get_direction(desc);
2040 spin_lock_irqsave(&gpio_lock, flags);
2043 spin_unlock_irqrestore(&gpio_lock, flags);
2048 * This descriptor validation needs to be inserted verbatim into each
2049 * function taking a descriptor, so we need to use a preprocessor
2050 * macro to avoid endless duplication. If the desc is NULL it is an
2051 * optional GPIO and calls should just bail out.
2053 #define VALIDATE_DESC(desc) do { \
2056 if (IS_ERR(desc)) { \
2057 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2058 return PTR_ERR(desc); \
2060 if (!desc->gdev) { \
2061 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2064 if ( !desc->gdev->chip ) { \
2065 dev_warn(&desc->gdev->dev, \
2066 "%s: backing chip is gone\n", __func__); \
2070 #define VALIDATE_DESC_VOID(desc) do { \
2073 if (IS_ERR(desc)) { \
2074 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2077 if (!desc->gdev) { \
2078 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2081 if (!desc->gdev->chip) { \
2082 dev_warn(&desc->gdev->dev, \
2083 "%s: backing chip is gone\n", __func__); \
2088 int gpiod_request(struct gpio_desc *desc, const char *label)
2090 int status = -EPROBE_DEFER;
2091 struct gpio_device *gdev;
2093 VALIDATE_DESC(desc);
2096 if (try_module_get(gdev->owner)) {
2097 status = __gpiod_request(desc, label);
2099 module_put(gdev->owner);
2101 get_device(&gdev->dev);
2105 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2110 static bool __gpiod_free(struct gpio_desc *desc)
2113 unsigned long flags;
2114 struct gpio_chip *chip;
2118 gpiod_unexport(desc);
2120 spin_lock_irqsave(&gpio_lock, flags);
2122 chip = desc->gdev->chip;
2123 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2125 spin_unlock_irqrestore(&gpio_lock, flags);
2126 might_sleep_if(chip->can_sleep);
2127 chip->free(chip, gpio_chip_hwgpio(desc));
2128 spin_lock_irqsave(&gpio_lock, flags);
2130 desc_set_label(desc, NULL);
2131 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2132 clear_bit(FLAG_REQUESTED, &desc->flags);
2133 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2134 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2135 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2139 spin_unlock_irqrestore(&gpio_lock, flags);
2143 void gpiod_free(struct gpio_desc *desc)
2145 if (desc && desc->gdev && __gpiod_free(desc)) {
2146 module_put(desc->gdev->owner);
2147 put_device(&desc->gdev->dev);
2149 WARN_ON(extra_checks);
2154 * gpiochip_is_requested - return string iff signal was requested
2155 * @chip: controller managing the signal
2156 * @offset: of signal within controller's 0..(ngpio - 1) range
2158 * Returns NULL if the GPIO is not currently requested, else a string.
2159 * The string returned is the label passed to gpio_request(); if none has been
2160 * passed it is a meaningless, non-NULL constant.
2162 * This function is for use by GPIO controller drivers. The label can
2163 * help with diagnostics, and knowing that the signal is used as a GPIO
2164 * can help avoid accidentally multiplexing it to another controller.
2166 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2168 struct gpio_desc *desc;
2170 if (offset >= chip->ngpio)
2173 desc = &chip->gpiodev->descs[offset];
2175 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2179 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2182 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2183 * @desc: GPIO descriptor to request
2184 * @label: label for the GPIO
2186 * Function allows GPIO chip drivers to request and use their own GPIO
2187 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2188 * function will not increase reference count of the GPIO chip module. This
2189 * allows the GPIO chip module to be unloaded as needed (we assume that the
2190 * GPIO chip driver handles freeing the GPIOs it has requested).
2192 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2195 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2199 chip_err(chip, "failed to get GPIO descriptor\n");
2203 err = __gpiod_request(desc, label);
2205 return ERR_PTR(err);
2209 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2212 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2213 * @desc: GPIO descriptor to free
2215 * Function frees the given GPIO requested previously with
2216 * gpiochip_request_own_desc().
2218 void gpiochip_free_own_desc(struct gpio_desc *desc)
2223 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2226 * Drivers MUST set GPIO direction before making get/set calls. In
2227 * some cases this is done in early boot, before IRQs are enabled.
2229 * As a rule these aren't called more than once (except for drivers
2230 * using the open-drain emulation idiom) so these are natural places
2231 * to accumulate extra debugging checks. Note that we can't (yet)
2232 * rely on gpio_request() having been called beforehand.
2236 * gpiod_direction_input - set the GPIO direction to input
2237 * @desc: GPIO to set to input
2239 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2240 * be called safely on it.
2242 * Return 0 in case of success, else an error code.
2244 int gpiod_direction_input(struct gpio_desc *desc)
2246 struct gpio_chip *chip;
2247 int status = -EINVAL;
2249 VALIDATE_DESC(desc);
2250 chip = desc->gdev->chip;
2252 if (!chip->get || !chip->direction_input) {
2254 "%s: missing get() or direction_input() operations\n",
2259 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2261 clear_bit(FLAG_IS_OUT, &desc->flags);
2263 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2267 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2269 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2270 enum pin_config_param mode)
2272 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2274 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2277 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2279 struct gpio_chip *gc = desc->gdev->chip;
2283 /* GPIOs used for IRQs shall not be set as output */
2284 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2286 "%s: tried to set a GPIO tied to an IRQ as output\n",
2291 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2292 /* First see if we can enable open drain in hardware */
2293 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2294 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2296 goto set_output_value;
2297 /* Emulate open drain by not actively driving the line high */
2299 return gpiod_direction_input(desc);
2301 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2302 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2303 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2305 goto set_output_value;
2306 /* Emulate open source by not actively driving the line low */
2308 return gpiod_direction_input(desc);
2310 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2311 PIN_CONFIG_DRIVE_PUSH_PULL);
2315 if (!gc->set || !gc->direction_output) {
2317 "%s: missing set() or direction_output() operations\n",
2322 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2324 set_bit(FLAG_IS_OUT, &desc->flags);
2325 trace_gpio_value(desc_to_gpio(desc), 0, val);
2326 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2331 * gpiod_direction_output_raw - set the GPIO direction to output
2332 * @desc: GPIO to set to output
2333 * @value: initial output value of the GPIO
2335 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2336 * be called safely on it. The initial value of the output must be specified
2337 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2339 * Return 0 in case of success, else an error code.
2341 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2343 VALIDATE_DESC(desc);
2344 return _gpiod_direction_output_raw(desc, value);
2346 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2349 * gpiod_direction_output - set the GPIO direction to output
2350 * @desc: GPIO to set to output
2351 * @value: initial output value of the GPIO
2353 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2354 * be called safely on it. The initial value of the output must be specified
2355 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2358 * Return 0 in case of success, else an error code.
2360 int gpiod_direction_output(struct gpio_desc *desc, int value)
2362 VALIDATE_DESC(desc);
2363 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2367 return _gpiod_direction_output_raw(desc, value);
2369 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2372 * gpiod_set_debounce - sets @debounce time for a @gpio
2373 * @gpio: the gpio to set debounce time
2374 * @debounce: debounce time is microseconds
2376 * returns -ENOTSUPP if the controller does not support setting
2379 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2381 struct gpio_chip *chip;
2382 unsigned long config;
2384 VALIDATE_DESC(desc);
2385 chip = desc->gdev->chip;
2386 if (!chip->set || !chip->set_config) {
2388 "%s: missing set() or set_config() operations\n",
2393 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2394 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2396 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2399 * gpiod_is_active_low - test whether a GPIO is active-low or not
2400 * @desc: the gpio descriptor to test
2402 * Returns 1 if the GPIO is active-low, 0 otherwise.
2404 int gpiod_is_active_low(const struct gpio_desc *desc)
2406 VALIDATE_DESC(desc);
2407 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2409 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2411 /* I/O calls are only valid after configuration completed; the relevant
2412 * "is this a valid GPIO" error checks should already have been done.
2414 * "Get" operations are often inlinable as reading a pin value register,
2415 * and masking the relevant bit in that register.
2417 * When "set" operations are inlinable, they involve writing that mask to
2418 * one register to set a low value, or a different register to set it high.
2419 * Otherwise locking is needed, so there may be little value to inlining.
2421 *------------------------------------------------------------------------
2423 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2424 * have requested the GPIO. That can include implicit requesting by
2425 * a direction setting call. Marking a gpio as requested locks its chip
2426 * in memory, guaranteeing that these table lookups need no more locking
2427 * and that gpiochip_remove() will fail.
2429 * REVISIT when debugging, consider adding some instrumentation to ensure
2430 * that the GPIO was actually requested.
2433 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
2435 struct gpio_chip *chip;
2439 chip = desc->gdev->chip;
2440 offset = gpio_chip_hwgpio(desc);
2441 value = chip->get ? chip->get(chip, offset) : -EIO;
2442 value = value < 0 ? value : !!value;
2443 trace_gpio_value(desc_to_gpio(desc), 1, value);
2448 * gpiod_get_raw_value() - return a gpio's raw value
2449 * @desc: gpio whose value will be returned
2451 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2452 * its ACTIVE_LOW status, or negative errno on failure.
2454 * This function should be called from contexts where we cannot sleep, and will
2455 * complain if the GPIO chip functions potentially sleep.
2457 int gpiod_get_raw_value(const struct gpio_desc *desc)
2459 VALIDATE_DESC(desc);
2460 /* Should be using gpio_get_value_cansleep() */
2461 WARN_ON(desc->gdev->chip->can_sleep);
2462 return _gpiod_get_raw_value(desc);
2464 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2467 * gpiod_get_value() - return a gpio's value
2468 * @desc: gpio whose value will be returned
2470 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2471 * account, or negative errno on failure.
2473 * This function should be called from contexts where we cannot sleep, and will
2474 * complain if the GPIO chip functions potentially sleep.
2476 int gpiod_get_value(const struct gpio_desc *desc)
2480 VALIDATE_DESC(desc);
2481 /* Should be using gpio_get_value_cansleep() */
2482 WARN_ON(desc->gdev->chip->can_sleep);
2484 value = _gpiod_get_raw_value(desc);
2488 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2493 EXPORT_SYMBOL_GPL(gpiod_get_value);
2496 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2497 * @desc: gpio descriptor whose state need to be set.
2498 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2500 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2503 struct gpio_chip *chip = desc->gdev->chip;
2504 int offset = gpio_chip_hwgpio(desc);
2507 err = chip->direction_input(chip, offset);
2509 clear_bit(FLAG_IS_OUT, &desc->flags);
2511 err = chip->direction_output(chip, offset, 0);
2513 set_bit(FLAG_IS_OUT, &desc->flags);
2515 trace_gpio_direction(desc_to_gpio(desc), value, err);
2518 "%s: Error in set_value for open drain err %d\n",
2523 * _gpio_set_open_source_value() - Set the open source gpio's value.
2524 * @desc: gpio descriptor whose state need to be set.
2525 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2527 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2530 struct gpio_chip *chip = desc->gdev->chip;
2531 int offset = gpio_chip_hwgpio(desc);
2534 err = chip->direction_output(chip, offset, 1);
2536 set_bit(FLAG_IS_OUT, &desc->flags);
2538 err = chip->direction_input(chip, offset);
2540 clear_bit(FLAG_IS_OUT, &desc->flags);
2542 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2545 "%s: Error in set_value for open source err %d\n",
2549 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2551 struct gpio_chip *chip;
2553 chip = desc->gdev->chip;
2554 trace_gpio_value(desc_to_gpio(desc), 0, value);
2555 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2556 _gpio_set_open_drain_value(desc, value);
2557 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2558 _gpio_set_open_source_value(desc, value);
2560 chip->set(chip, gpio_chip_hwgpio(desc), value);
2564 * set multiple outputs on the same chip;
2565 * use the chip's set_multiple function if available;
2566 * otherwise set the outputs sequentially;
2567 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2568 * defines which outputs are to be changed
2569 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2570 * defines the values the outputs specified by mask are to be set to
2572 static void gpio_chip_set_multiple(struct gpio_chip *chip,
2573 unsigned long *mask, unsigned long *bits)
2575 if (chip->set_multiple) {
2576 chip->set_multiple(chip, mask, bits);
2580 /* set outputs if the corresponding mask bit is set */
2581 for_each_set_bit(i, mask, chip->ngpio)
2582 chip->set(chip, i, test_bit(i, bits));
2586 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2587 unsigned int array_size,
2588 struct gpio_desc **desc_array,
2593 while (i < array_size) {
2594 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2595 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2596 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2600 WARN_ON(chip->can_sleep);
2602 memset(mask, 0, sizeof(mask));
2604 struct gpio_desc *desc = desc_array[i];
2605 int hwgpio = gpio_chip_hwgpio(desc);
2606 int value = value_array[i];
2608 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2610 trace_gpio_value(desc_to_gpio(desc), 0, value);
2612 * collect all normal outputs belonging to the same chip
2613 * open drain and open source outputs are set individually
2615 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2616 _gpio_set_open_drain_value(desc, value);
2617 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2618 _gpio_set_open_source_value(desc, value);
2620 __set_bit(hwgpio, mask);
2622 __set_bit(hwgpio, bits);
2624 __clear_bit(hwgpio, bits);
2628 } while ((i < array_size) &&
2629 (desc_array[i]->gdev->chip == chip));
2630 /* push collected bits to outputs */
2632 gpio_chip_set_multiple(chip, mask, bits);
2637 * gpiod_set_raw_value() - assign a gpio's raw value
2638 * @desc: gpio whose value will be assigned
2639 * @value: value to assign
2641 * Set the raw value of the GPIO, i.e. the value of its physical line without
2642 * regard for its ACTIVE_LOW status.
2644 * This function should be called from contexts where we cannot sleep, and will
2645 * complain if the GPIO chip functions potentially sleep.
2647 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2649 VALIDATE_DESC_VOID(desc);
2650 /* Should be using gpiod_set_value_cansleep() */
2651 WARN_ON(desc->gdev->chip->can_sleep);
2652 _gpiod_set_raw_value(desc, value);
2654 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2657 * gpiod_set_value() - assign a gpio's value
2658 * @desc: gpio whose value will be assigned
2659 * @value: value to assign
2661 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2664 * This function should be called from contexts where we cannot sleep, and will
2665 * complain if the GPIO chip functions potentially sleep.
2667 void gpiod_set_value(struct gpio_desc *desc, int value)
2669 VALIDATE_DESC_VOID(desc);
2670 /* Should be using gpiod_set_value_cansleep() */
2671 WARN_ON(desc->gdev->chip->can_sleep);
2672 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2674 _gpiod_set_raw_value(desc, value);
2676 EXPORT_SYMBOL_GPL(gpiod_set_value);
2679 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2680 * @array_size: number of elements in the descriptor / value arrays
2681 * @desc_array: array of GPIO descriptors whose values will be assigned
2682 * @value_array: array of values to assign
2684 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2685 * without regard for their ACTIVE_LOW status.
2687 * This function should be called from contexts where we cannot sleep, and will
2688 * complain if the GPIO chip functions potentially sleep.
2690 void gpiod_set_raw_array_value(unsigned int array_size,
2691 struct gpio_desc **desc_array, int *value_array)
2695 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2698 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2701 * gpiod_set_array_value() - assign values to an array of GPIOs
2702 * @array_size: number of elements in the descriptor / value arrays
2703 * @desc_array: array of GPIO descriptors whose values will be assigned
2704 * @value_array: array of values to assign
2706 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2709 * This function should be called from contexts where we cannot sleep, and will
2710 * complain if the GPIO chip functions potentially sleep.
2712 void gpiod_set_array_value(unsigned int array_size,
2713 struct gpio_desc **desc_array, int *value_array)
2717 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2720 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2723 * gpiod_cansleep() - report whether gpio value access may sleep
2724 * @desc: gpio to check
2727 int gpiod_cansleep(const struct gpio_desc *desc)
2729 VALIDATE_DESC(desc);
2730 return desc->gdev->chip->can_sleep;
2732 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2735 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2736 * @desc: gpio whose IRQ will be returned (already requested)
2738 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2741 int gpiod_to_irq(const struct gpio_desc *desc)
2743 struct gpio_chip *chip;
2747 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2748 * requires this function to not return zero on an invalid descriptor
2749 * but rather a negative error number.
2751 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2754 chip = desc->gdev->chip;
2755 offset = gpio_chip_hwgpio(desc);
2757 int retirq = chip->to_irq(chip, offset);
2759 /* Zero means NO_IRQ */
2767 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2770 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2771 * @chip: the chip the GPIO to lock belongs to
2772 * @offset: the offset of the GPIO to lock as IRQ
2774 * This is used directly by GPIO drivers that want to lock down
2775 * a certain GPIO line to be used for IRQs.
2777 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2779 struct gpio_desc *desc;
2781 desc = gpiochip_get_desc(chip, offset);
2783 return PTR_ERR(desc);
2786 * If it's fast: flush the direction setting if something changed
2789 if (!chip->can_sleep && chip->get_direction) {
2790 int dir = chip->get_direction(chip, offset);
2793 clear_bit(FLAG_IS_OUT, &desc->flags);
2795 set_bit(FLAG_IS_OUT, &desc->flags);
2798 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2800 "%s: tried to flag a GPIO set as output for IRQ\n",
2805 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2808 * If the consumer has not set up a label (such as when the
2809 * IRQ is referenced from .to_irq()) we set up a label here
2810 * so it is clear this is used as an interrupt.
2813 desc_set_label(desc, "interrupt");
2817 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2820 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2821 * @chip: the chip the GPIO to lock belongs to
2822 * @offset: the offset of the GPIO to lock as IRQ
2824 * This is used directly by GPIO drivers that want to indicate
2825 * that a certain GPIO is no longer used exclusively for IRQ.
2827 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2829 struct gpio_desc *desc;
2831 desc = gpiochip_get_desc(chip, offset);
2835 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
2837 /* If we only had this marking, erase it */
2838 if (desc->label && !strcmp(desc->label, "interrupt"))
2839 desc_set_label(desc, NULL);
2841 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2843 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2845 if (offset >= chip->ngpio)
2848 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2850 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2852 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2854 if (offset >= chip->ngpio)
2857 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2859 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2861 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2863 if (offset >= chip->ngpio)
2866 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2868 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2870 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
2872 if (offset >= chip->ngpio)
2875 return !test_bit(FLAG_SLEEP_MAY_LOOSE_VALUE,
2876 &chip->gpiodev->descs[offset].flags);
2878 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
2881 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2882 * @desc: gpio whose value will be returned
2884 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2885 * its ACTIVE_LOW status, or negative errno on failure.
2887 * This function is to be called from contexts that can sleep.
2889 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2891 might_sleep_if(extra_checks);
2892 VALIDATE_DESC(desc);
2893 return _gpiod_get_raw_value(desc);
2895 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2898 * gpiod_get_value_cansleep() - return a gpio's value
2899 * @desc: gpio whose value will be returned
2901 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2902 * account, or negative errno on failure.
2904 * This function is to be called from contexts that can sleep.
2906 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2910 might_sleep_if(extra_checks);
2911 VALIDATE_DESC(desc);
2912 value = _gpiod_get_raw_value(desc);
2916 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2921 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2924 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2925 * @desc: gpio whose value will be assigned
2926 * @value: value to assign
2928 * Set the raw value of the GPIO, i.e. the value of its physical line without
2929 * regard for its ACTIVE_LOW status.
2931 * This function is to be called from contexts that can sleep.
2933 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2935 might_sleep_if(extra_checks);
2936 VALIDATE_DESC_VOID(desc);
2937 _gpiod_set_raw_value(desc, value);
2939 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2942 * gpiod_set_value_cansleep() - assign a gpio's value
2943 * @desc: gpio whose value will be assigned
2944 * @value: value to assign
2946 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2949 * This function is to be called from contexts that can sleep.
2951 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2953 might_sleep_if(extra_checks);
2954 VALIDATE_DESC_VOID(desc);
2955 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2957 _gpiod_set_raw_value(desc, value);
2959 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2962 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2963 * @array_size: number of elements in the descriptor / value arrays
2964 * @desc_array: array of GPIO descriptors whose values will be assigned
2965 * @value_array: array of values to assign
2967 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2968 * without regard for their ACTIVE_LOW status.
2970 * This function is to be called from contexts that can sleep.
2972 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2973 struct gpio_desc **desc_array,
2976 might_sleep_if(extra_checks);
2979 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2982 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2985 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2986 * @array_size: number of elements in the descriptor / value arrays
2987 * @desc_array: array of GPIO descriptors whose values will be assigned
2988 * @value_array: array of values to assign
2990 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2993 * This function is to be called from contexts that can sleep.
2995 void gpiod_set_array_value_cansleep(unsigned int array_size,
2996 struct gpio_desc **desc_array,
2999 might_sleep_if(extra_checks);
3002 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3005 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3008 * gpiod_add_lookup_table() - register GPIO device consumers
3009 * @table: table of consumers to register
3011 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3013 mutex_lock(&gpio_lookup_lock);
3015 list_add_tail(&table->list, &gpio_lookup_list);
3017 mutex_unlock(&gpio_lookup_lock);
3019 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3022 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3023 * @table: table of consumers to unregister
3025 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3027 mutex_lock(&gpio_lookup_lock);
3029 list_del(&table->list);
3031 mutex_unlock(&gpio_lookup_lock);
3033 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3035 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3037 const char *dev_id = dev ? dev_name(dev) : NULL;
3038 struct gpiod_lookup_table *table;
3040 mutex_lock(&gpio_lookup_lock);
3042 list_for_each_entry(table, &gpio_lookup_list, list) {
3043 if (table->dev_id && dev_id) {
3045 * Valid strings on both ends, must be identical to have
3048 if (!strcmp(table->dev_id, dev_id))
3052 * One of the pointers is NULL, so both must be to have
3055 if (dev_id == table->dev_id)
3062 mutex_unlock(&gpio_lookup_lock);
3066 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3068 enum gpio_lookup_flags *flags)
3070 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3071 struct gpiod_lookup_table *table;
3072 struct gpiod_lookup *p;
3074 table = gpiod_find_lookup_table(dev);
3078 for (p = &table->table[0]; p->chip_label; p++) {
3079 struct gpio_chip *chip;
3081 /* idx must always match exactly */
3085 /* If the lookup entry has a con_id, require exact match */
3086 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3089 chip = find_chip_by_name(p->chip_label);
3092 dev_err(dev, "cannot find GPIO chip %s\n",
3094 return ERR_PTR(-ENODEV);
3097 if (chip->ngpio <= p->chip_hwnum) {
3099 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3100 idx, chip->ngpio, chip->label);
3101 return ERR_PTR(-EINVAL);
3104 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3113 static int dt_gpio_count(struct device *dev, const char *con_id)
3119 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3121 snprintf(propname, sizeof(propname), "%s-%s",
3122 con_id, gpio_suffixes[i]);
3124 snprintf(propname, sizeof(propname), "%s",
3127 ret = of_gpio_named_count(dev->of_node, propname);
3131 return ret ? ret : -ENOENT;
3134 static int platform_gpio_count(struct device *dev, const char *con_id)
3136 struct gpiod_lookup_table *table;
3137 struct gpiod_lookup *p;
3138 unsigned int count = 0;
3140 table = gpiod_find_lookup_table(dev);
3144 for (p = &table->table[0]; p->chip_label; p++) {
3145 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3146 (!con_id && !p->con_id))
3156 * gpiod_count - return the number of GPIOs associated with a device / function
3157 * or -ENOENT if no GPIO has been assigned to the requested function
3158 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3159 * @con_id: function within the GPIO consumer
3161 int gpiod_count(struct device *dev, const char *con_id)
3163 int count = -ENOENT;
3165 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3166 count = dt_gpio_count(dev, con_id);
3167 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3168 count = acpi_gpio_count(dev, con_id);
3171 count = platform_gpio_count(dev, con_id);
3175 EXPORT_SYMBOL_GPL(gpiod_count);
3178 * gpiod_get - obtain a GPIO for a given GPIO function
3179 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3180 * @con_id: function within the GPIO consumer
3181 * @flags: optional GPIO initialization flags
3183 * Return the GPIO descriptor corresponding to the function con_id of device
3184 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3185 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3187 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3188 enum gpiod_flags flags)
3190 return gpiod_get_index(dev, con_id, 0, flags);
3192 EXPORT_SYMBOL_GPL(gpiod_get);
3195 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3196 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3197 * @con_id: function within the GPIO consumer
3198 * @flags: optional GPIO initialization flags
3200 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3201 * the requested function it will return NULL. This is convenient for drivers
3202 * that need to handle optional GPIOs.
3204 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3206 enum gpiod_flags flags)
3208 return gpiod_get_index_optional(dev, con_id, 0, flags);
3210 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3214 * gpiod_configure_flags - helper function to configure a given GPIO
3215 * @desc: gpio whose value will be assigned
3216 * @con_id: function within the GPIO consumer
3217 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3219 * @dflags: gpiod_flags - optional GPIO initialization flags
3221 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3222 * requested function and/or index, or another IS_ERR() code if an error
3223 * occurred while trying to acquire the GPIO.
3225 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3226 unsigned long lflags, enum gpiod_flags dflags)
3230 if (lflags & GPIO_ACTIVE_LOW)
3231 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3232 if (lflags & GPIO_OPEN_DRAIN)
3233 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3234 if (lflags & GPIO_OPEN_SOURCE)
3235 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3236 if (lflags & GPIO_SLEEP_MAY_LOOSE_VALUE)
3237 set_bit(FLAG_SLEEP_MAY_LOOSE_VALUE, &desc->flags);
3239 /* No particular flag request, return here... */
3240 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3241 pr_debug("no flags found for %s\n", con_id);
3246 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3247 status = gpiod_direction_output(desc,
3248 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3250 status = gpiod_direction_input(desc);
3256 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3257 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3258 * @con_id: function within the GPIO consumer
3259 * @idx: index of the GPIO to obtain in the consumer
3260 * @flags: optional GPIO initialization flags
3262 * This variant of gpiod_get() allows to access GPIOs other than the first
3263 * defined one for functions that define several GPIOs.
3265 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3266 * requested function and/or index, or another IS_ERR() code if an error
3267 * occurred while trying to acquire the GPIO.
3269 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3272 enum gpiod_flags flags)
3274 struct gpio_desc *desc = NULL;
3276 enum gpio_lookup_flags lookupflags = 0;
3278 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3281 /* Using device tree? */
3282 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3283 dev_dbg(dev, "using device tree for GPIO lookup\n");
3284 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3285 } else if (ACPI_COMPANION(dev)) {
3286 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3287 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3292 * Either we are not using DT or ACPI, or their lookup did not return
3293 * a result. In that case, use platform lookup as a fallback.
3295 if (!desc || desc == ERR_PTR(-ENOENT)) {
3296 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3297 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3301 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
3305 status = gpiod_request(desc, con_id);
3307 return ERR_PTR(status);
3309 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3311 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3313 return ERR_PTR(status);
3318 EXPORT_SYMBOL_GPL(gpiod_get_index);
3321 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3322 * @fwnode: handle of the firmware node
3323 * @propname: name of the firmware property representing the GPIO
3324 * @index: index of the GPIO to obtain in the consumer
3325 * @dflags: GPIO initialization flags
3327 * This function can be used for drivers that get their configuration
3330 * Function properly finds the corresponding GPIO using whatever is the
3331 * underlying firmware interface and then makes sure that the GPIO
3332 * descriptor is requested before it is returned to the caller.
3334 * On successful request the GPIO pin is configured in accordance with
3337 * In case of error an ERR_PTR() is returned.
3339 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3340 const char *propname, int index,
3341 enum gpiod_flags dflags,
3344 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3345 unsigned long lflags = 0;
3346 bool active_low = false;
3347 bool single_ended = false;
3348 bool open_drain = false;
3352 return ERR_PTR(-EINVAL);
3354 if (is_of_node(fwnode)) {
3355 enum of_gpio_flags flags;
3357 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname,
3359 if (!IS_ERR(desc)) {
3360 active_low = flags & OF_GPIO_ACTIVE_LOW;
3361 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3362 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3364 } else if (is_acpi_node(fwnode)) {
3365 struct acpi_gpio_info info;
3367 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
3368 if (!IS_ERR(desc)) {
3369 active_low = info.polarity == GPIO_ACTIVE_LOW;
3370 ret = acpi_gpio_update_gpiod_flags(&dflags, info.flags);
3372 pr_debug("Override GPIO initialization flags\n");
3379 ret = gpiod_request(desc, label);
3381 return ERR_PTR(ret);
3384 lflags |= GPIO_ACTIVE_LOW;
3388 lflags |= GPIO_OPEN_DRAIN;
3390 lflags |= GPIO_OPEN_SOURCE;
3393 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3396 return ERR_PTR(ret);
3401 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3404 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3406 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3407 * @con_id: function within the GPIO consumer
3408 * @index: index of the GPIO to obtain in the consumer
3409 * @flags: optional GPIO initialization flags
3411 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3412 * specified index was assigned to the requested function it will return NULL.
3413 * This is convenient for drivers that need to handle optional GPIOs.
3415 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3418 enum gpiod_flags flags)
3420 struct gpio_desc *desc;
3422 desc = gpiod_get_index(dev, con_id, index, flags);
3424 if (PTR_ERR(desc) == -ENOENT)
3430 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3433 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3434 * @desc: gpio whose value will be assigned
3435 * @name: gpio line name
3436 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3438 * @dflags: gpiod_flags - optional GPIO initialization flags
3440 int gpiod_hog(struct gpio_desc *desc, const char *name,
3441 unsigned long lflags, enum gpiod_flags dflags)
3443 struct gpio_chip *chip;
3444 struct gpio_desc *local_desc;
3448 chip = gpiod_to_chip(desc);
3449 hwnum = gpio_chip_hwgpio(desc);
3451 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3452 if (IS_ERR(local_desc)) {
3453 status = PTR_ERR(local_desc);
3454 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3455 name, chip->label, hwnum, status);
3459 status = gpiod_configure_flags(desc, name, lflags, dflags);
3461 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3462 name, chip->label, hwnum, status);
3463 gpiochip_free_own_desc(desc);
3467 /* Mark GPIO as hogged so it can be identified and removed later */
3468 set_bit(FLAG_IS_HOGGED, &desc->flags);
3470 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3471 desc_to_gpio(desc), name,
3472 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3473 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3474 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3480 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3481 * @chip: gpio chip to act on
3483 * This is only used by of_gpiochip_remove to free hogged gpios
3485 static void gpiochip_free_hogs(struct gpio_chip *chip)
3489 for (id = 0; id < chip->ngpio; id++) {
3490 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3491 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3496 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3497 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3498 * @con_id: function within the GPIO consumer
3499 * @flags: optional GPIO initialization flags
3501 * This function acquires all the GPIOs defined under a given function.
3503 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3504 * no GPIO has been assigned to the requested function, or another IS_ERR()
3505 * code if an error occurred while trying to acquire the GPIOs.
3507 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
3509 enum gpiod_flags flags)
3511 struct gpio_desc *desc;
3512 struct gpio_descs *descs;
3515 count = gpiod_count(dev, con_id);
3517 return ERR_PTR(count);
3519 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
3522 return ERR_PTR(-ENOMEM);
3524 for (descs->ndescs = 0; descs->ndescs < count; ) {
3525 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
3527 gpiod_put_array(descs);
3528 return ERR_CAST(desc);
3530 descs->desc[descs->ndescs] = desc;
3535 EXPORT_SYMBOL_GPL(gpiod_get_array);
3538 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3540 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3541 * @con_id: function within the GPIO consumer
3542 * @flags: optional GPIO initialization flags
3544 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3545 * assigned to the requested function it will return NULL.
3547 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
3549 enum gpiod_flags flags)
3551 struct gpio_descs *descs;
3553 descs = gpiod_get_array(dev, con_id, flags);
3554 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
3559 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
3562 * gpiod_put - dispose of a GPIO descriptor
3563 * @desc: GPIO descriptor to dispose of
3565 * No descriptor can be used after gpiod_put() has been called on it.
3567 void gpiod_put(struct gpio_desc *desc)
3571 EXPORT_SYMBOL_GPL(gpiod_put);
3574 * gpiod_put_array - dispose of multiple GPIO descriptors
3575 * @descs: struct gpio_descs containing an array of descriptors
3577 void gpiod_put_array(struct gpio_descs *descs)
3581 for (i = 0; i < descs->ndescs; i++)
3582 gpiod_put(descs->desc[i]);
3586 EXPORT_SYMBOL_GPL(gpiod_put_array);
3588 static int __init gpiolib_dev_init(void)
3592 /* Register GPIO sysfs bus */
3593 ret = bus_register(&gpio_bus_type);
3595 pr_err("gpiolib: could not register GPIO bus type\n");
3599 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
3601 pr_err("gpiolib: failed to allocate char dev region\n");
3602 bus_unregister(&gpio_bus_type);
3604 gpiolib_initialized = true;
3605 gpiochip_setup_devs();
3609 core_initcall(gpiolib_dev_init);
3611 #ifdef CONFIG_DEBUG_FS
3613 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
3616 struct gpio_chip *chip = gdev->chip;
3617 unsigned gpio = gdev->base;
3618 struct gpio_desc *gdesc = &gdev->descs[0];
3622 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
3623 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
3625 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
3631 gpiod_get_direction(gdesc);
3632 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
3633 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
3634 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3635 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
3636 is_out ? "out" : "in ",
3638 ? (chip->get(chip, i) ? "hi" : "lo")
3640 is_irq ? "IRQ" : " ");
3641 seq_printf(s, "\n");
3645 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
3647 unsigned long flags;
3648 struct gpio_device *gdev = NULL;
3649 loff_t index = *pos;
3653 spin_lock_irqsave(&gpio_lock, flags);
3654 list_for_each_entry(gdev, &gpio_devices, list)
3656 spin_unlock_irqrestore(&gpio_lock, flags);
3659 spin_unlock_irqrestore(&gpio_lock, flags);
3664 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3666 unsigned long flags;
3667 struct gpio_device *gdev = v;
3670 spin_lock_irqsave(&gpio_lock, flags);
3671 if (list_is_last(&gdev->list, &gpio_devices))
3674 ret = list_entry(gdev->list.next, struct gpio_device, list);
3675 spin_unlock_irqrestore(&gpio_lock, flags);
3683 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3687 static int gpiolib_seq_show(struct seq_file *s, void *v)
3689 struct gpio_device *gdev = v;
3690 struct gpio_chip *chip = gdev->chip;
3691 struct device *parent;
3694 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3695 dev_name(&gdev->dev));
3699 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3700 dev_name(&gdev->dev),
3701 gdev->base, gdev->base + gdev->ngpio - 1);
3702 parent = chip->parent;
3704 seq_printf(s, ", parent: %s/%s",
3705 parent->bus ? parent->bus->name : "no-bus",
3708 seq_printf(s, ", %s", chip->label);
3709 if (chip->can_sleep)
3710 seq_printf(s, ", can sleep");
3711 seq_printf(s, ":\n");
3714 chip->dbg_show(s, chip);
3716 gpiolib_dbg_show(s, gdev);
3721 static const struct seq_operations gpiolib_seq_ops = {
3722 .start = gpiolib_seq_start,
3723 .next = gpiolib_seq_next,
3724 .stop = gpiolib_seq_stop,
3725 .show = gpiolib_seq_show,
3728 static int gpiolib_open(struct inode *inode, struct file *file)
3730 return seq_open(file, &gpiolib_seq_ops);
3733 static const struct file_operations gpiolib_operations = {
3734 .owner = THIS_MODULE,
3735 .open = gpiolib_open,
3737 .llseek = seq_lseek,
3738 .release = seq_release,
3741 static int __init gpiolib_debugfs_init(void)
3743 /* /sys/kernel/debug/gpio */
3744 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3745 NULL, NULL, &gpiolib_operations);
3748 subsys_initcall(gpiolib_debugfs_init);
3750 #endif /* DEBUG_FS */