1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/interrupt.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/device.h>
9 #include <linux/debugfs.h>
10 #include <linux/seq_file.h>
11 #include <linux/gpio.h>
12 #include <linux/of_gpio.h>
13 #include <linux/idr.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/gpio/machine.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/cdev.h>
21 #include <linux/uaccess.h>
22 #include <linux/compat.h>
23 #include <linux/anon_inodes.h>
24 #include <linux/kfifo.h>
25 #include <linux/poll.h>
26 #include <linux/timekeeping.h>
27 #include <uapi/linux/gpio.h>
31 #define CREATE_TRACE_POINTS
32 #include <trace/events/gpio.h>
34 /* Implementation infrastructure for GPIO interfaces.
36 * The GPIO programming interface allows for inlining speed-critical
37 * get/set operations for common cases, so that access to SOC-integrated
38 * GPIOs can sometimes cost only an instruction or two per bit.
42 /* When debugging, extend minimal trust to callers and platform code.
43 * Also emit diagnostic messages that may help initial bringup, when
44 * board setup or driver bugs are most common.
46 * Otherwise, minimize overhead in what may be bitbanging codepaths.
49 #define extra_checks 1
51 #define extra_checks 0
54 /* Device and char device-related information */
55 static DEFINE_IDA(gpio_ida);
56 static dev_t gpio_devt;
57 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
58 static struct bus_type gpio_bus_type = {
62 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
63 * While any GPIO is requested, its gpio_chip is not removable;
64 * each GPIO's "requested" flag serves as a lock and refcount.
66 DEFINE_SPINLOCK(gpio_lock);
68 static DEFINE_MUTEX(gpio_lookup_lock);
69 static LIST_HEAD(gpio_lookup_list);
70 LIST_HEAD(gpio_devices);
72 static void gpiochip_free_hogs(struct gpio_chip *chip);
73 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
75 static bool gpiolib_initialized;
77 static inline void desc_set_label(struct gpio_desc *d, const char *label)
83 * Convert a GPIO number to its descriptor
85 struct gpio_desc *gpio_to_desc(unsigned gpio)
87 struct gpio_device *gdev;
90 spin_lock_irqsave(&gpio_lock, flags);
92 list_for_each_entry(gdev, &gpio_devices, list) {
93 if (gdev->base <= gpio &&
94 gdev->base + gdev->ngpio > gpio) {
95 spin_unlock_irqrestore(&gpio_lock, flags);
96 return &gdev->descs[gpio - gdev->base];
100 spin_unlock_irqrestore(&gpio_lock, flags);
102 if (!gpio_is_valid(gpio))
103 WARN(1, "invalid GPIO %d\n", gpio);
107 EXPORT_SYMBOL_GPL(gpio_to_desc);
110 * Get the GPIO descriptor corresponding to the given hw number for this chip.
112 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
115 struct gpio_device *gdev = chip->gpiodev;
117 if (hwnum >= gdev->ngpio)
118 return ERR_PTR(-EINVAL);
120 return &gdev->descs[hwnum];
124 * Convert a GPIO descriptor to the integer namespace.
125 * This should disappear in the future but is needed since we still
126 * use GPIO numbers for error messages and sysfs nodes
128 int desc_to_gpio(const struct gpio_desc *desc)
130 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
132 EXPORT_SYMBOL_GPL(desc_to_gpio);
136 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
137 * @desc: descriptor to return the chip of
139 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
141 if (!desc || !desc->gdev || !desc->gdev->chip)
143 return desc->gdev->chip;
145 EXPORT_SYMBOL_GPL(gpiod_to_chip);
147 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
148 static int gpiochip_find_base(int ngpio)
150 struct gpio_device *gdev;
151 int base = ARCH_NR_GPIOS - ngpio;
153 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
154 /* found a free space? */
155 if (gdev->base + gdev->ngpio <= base)
158 /* nope, check the space right before the chip */
159 base = gdev->base - ngpio;
162 if (gpio_is_valid(base)) {
163 pr_debug("%s: found new base at %d\n", __func__, base);
166 pr_err("%s: cannot find free range\n", __func__);
172 * gpiod_get_direction - return the current direction of a GPIO
173 * @desc: GPIO to get the direction of
175 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
177 * This function may sleep if gpiod_cansleep() is true.
179 int gpiod_get_direction(struct gpio_desc *desc)
181 struct gpio_chip *chip;
183 int status = -EINVAL;
185 chip = gpiod_to_chip(desc);
186 offset = gpio_chip_hwgpio(desc);
188 if (!chip->get_direction)
191 status = chip->get_direction(chip, offset);
193 /* GPIOF_DIR_IN, or other positive */
195 clear_bit(FLAG_IS_OUT, &desc->flags);
199 set_bit(FLAG_IS_OUT, &desc->flags);
203 EXPORT_SYMBOL_GPL(gpiod_get_direction);
206 * Add a new chip to the global chips list, keeping the list of chips sorted
207 * by range(means [base, base + ngpio - 1]) order.
209 * Return -EBUSY if the new chip overlaps with some other chip's integer
212 static int gpiodev_add_to_list(struct gpio_device *gdev)
214 struct gpio_device *prev, *next;
216 if (list_empty(&gpio_devices)) {
217 /* initial entry in list */
218 list_add_tail(&gdev->list, &gpio_devices);
222 next = list_entry(gpio_devices.next, struct gpio_device, list);
223 if (gdev->base + gdev->ngpio <= next->base) {
224 /* add before first entry */
225 list_add(&gdev->list, &gpio_devices);
229 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
230 if (prev->base + prev->ngpio <= gdev->base) {
231 /* add behind last entry */
232 list_add_tail(&gdev->list, &gpio_devices);
236 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
237 /* at the end of the list */
238 if (&next->list == &gpio_devices)
241 /* add between prev and next */
242 if (prev->base + prev->ngpio <= gdev->base
243 && gdev->base + gdev->ngpio <= next->base) {
244 list_add(&gdev->list, &prev->list);
249 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
254 * Convert a GPIO name to its descriptor
256 static struct gpio_desc *gpio_name_to_desc(const char * const name)
258 struct gpio_device *gdev;
261 spin_lock_irqsave(&gpio_lock, flags);
263 list_for_each_entry(gdev, &gpio_devices, list) {
266 for (i = 0; i != gdev->ngpio; ++i) {
267 struct gpio_desc *desc = &gdev->descs[i];
269 if (!desc->name || !name)
272 if (!strcmp(desc->name, name)) {
273 spin_unlock_irqrestore(&gpio_lock, flags);
279 spin_unlock_irqrestore(&gpio_lock, flags);
285 * Takes the names from gc->names and checks if they are all unique. If they
286 * are, they are assigned to their gpio descriptors.
288 * Warning if one of the names is already used for a different GPIO.
290 static int gpiochip_set_desc_names(struct gpio_chip *gc)
292 struct gpio_device *gdev = gc->gpiodev;
298 /* First check all names if they are unique */
299 for (i = 0; i != gc->ngpio; ++i) {
300 struct gpio_desc *gpio;
302 gpio = gpio_name_to_desc(gc->names[i]);
305 "Detected name collision for GPIO name '%s'\n",
309 /* Then add all names to the GPIO descriptors */
310 for (i = 0; i != gc->ngpio; ++i)
311 gdev->descs[i].name = gc->names[i];
317 * GPIO line handle management
321 * struct linehandle_state - contains the state of a userspace handle
322 * @gdev: the GPIO device the handle pertains to
323 * @label: consumer label used to tag descriptors
324 * @descs: the GPIO descriptors held by this handle
325 * @numdescs: the number of descriptors held in the descs array
327 struct linehandle_state {
328 struct gpio_device *gdev;
330 struct gpio_desc *descs[GPIOHANDLES_MAX];
334 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
337 struct linehandle_state *lh = filep->private_data;
338 void __user *ip = (void __user *)arg;
339 struct gpiohandle_data ghd;
342 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
345 /* TODO: check if descriptors are really input */
346 for (i = 0; i < lh->numdescs; i++) {
347 val = gpiod_get_value_cansleep(lh->descs[i]);
353 if (copy_to_user(ip, &ghd, sizeof(ghd)))
357 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
358 int vals[GPIOHANDLES_MAX];
360 /* TODO: check if descriptors are really output */
361 if (copy_from_user(&ghd, ip, sizeof(ghd)))
364 /* Clamp all values to [0,1] */
365 for (i = 0; i < lh->numdescs; i++)
366 vals[i] = !!ghd.values[i];
368 /* Reuse the array setting function */
369 gpiod_set_array_value_complex(false,
380 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
383 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
387 static int linehandle_release(struct inode *inode, struct file *filep)
389 struct linehandle_state *lh = filep->private_data;
390 struct gpio_device *gdev = lh->gdev;
393 for (i = 0; i < lh->numdescs; i++)
394 gpiod_free(lh->descs[i]);
397 put_device(&gdev->dev);
401 static const struct file_operations linehandle_fileops = {
402 .release = linehandle_release,
403 .owner = THIS_MODULE,
404 .llseek = noop_llseek,
405 .unlocked_ioctl = linehandle_ioctl,
407 .compat_ioctl = linehandle_ioctl_compat,
411 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
413 struct gpiohandle_request handlereq;
414 struct linehandle_state *lh;
417 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
419 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
422 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
426 get_device(&gdev->dev);
428 /* Make sure this is terminated */
429 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
430 if (strlen(handlereq.consumer_label)) {
431 lh->label = kstrdup(handlereq.consumer_label,
439 /* Request each GPIO */
440 for (i = 0; i < handlereq.lines; i++) {
441 u32 offset = handlereq.lineoffsets[i];
442 u32 lflags = handlereq.flags;
443 struct gpio_desc *desc;
445 desc = &gdev->descs[offset];
446 ret = gpiod_request(desc, lh->label);
451 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
452 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
453 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
454 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
455 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
456 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
459 * Lines have to be requested explicitly for input
460 * or output, else the line will be treated "as is".
462 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
463 int val = !!handlereq.default_values[i];
465 ret = gpiod_direction_output(desc, val);
468 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
469 ret = gpiod_direction_input(desc);
473 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
476 /* Let i point at the last handle */
478 lh->numdescs = handlereq.lines;
480 fd = anon_inode_getfd("gpio-linehandle",
483 O_RDONLY | O_CLOEXEC);
490 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
495 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
502 gpiod_free(lh->descs[i]);
506 put_device(&gdev->dev);
511 * GPIO line event management
515 * struct lineevent_state - contains the state of a userspace event
516 * @gdev: the GPIO device the event pertains to
517 * @label: consumer label used to tag descriptors
518 * @desc: the GPIO descriptor held by this event
519 * @eflags: the event flags this line was requested with
520 * @irq: the interrupt that trigger in response to events on this GPIO
521 * @wait: wait queue that handles blocking reads of events
522 * @events: KFIFO for the GPIO events
523 * @read_lock: mutex lock to protect reads from colliding with adding
524 * new events to the FIFO
526 struct lineevent_state {
527 struct gpio_device *gdev;
529 struct gpio_desc *desc;
532 wait_queue_head_t wait;
533 DECLARE_KFIFO(events, struct gpioevent_data, 16);
534 struct mutex read_lock;
537 static unsigned int lineevent_poll(struct file *filep,
538 struct poll_table_struct *wait)
540 struct lineevent_state *le = filep->private_data;
541 unsigned int events = 0;
543 poll_wait(filep, &le->wait, wait);
545 if (!kfifo_is_empty(&le->events))
546 events = POLLIN | POLLRDNORM;
552 static ssize_t lineevent_read(struct file *filep,
557 struct lineevent_state *le = filep->private_data;
561 if (count < sizeof(struct gpioevent_data))
565 if (kfifo_is_empty(&le->events)) {
566 if (filep->f_flags & O_NONBLOCK)
569 ret = wait_event_interruptible(le->wait,
570 !kfifo_is_empty(&le->events));
575 if (mutex_lock_interruptible(&le->read_lock))
577 ret = kfifo_to_user(&le->events, buf, count, &copied);
578 mutex_unlock(&le->read_lock);
584 * If we couldn't read anything from the fifo (a different
585 * thread might have been faster) we either return -EAGAIN if
586 * the file descriptor is non-blocking, otherwise we go back to
587 * sleep and wait for more data to arrive.
589 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
592 } while (copied == 0);
597 static int lineevent_release(struct inode *inode, struct file *filep)
599 struct lineevent_state *le = filep->private_data;
600 struct gpio_device *gdev = le->gdev;
602 free_irq(le->irq, le);
603 gpiod_free(le->desc);
606 put_device(&gdev->dev);
610 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
613 struct lineevent_state *le = filep->private_data;
614 void __user *ip = (void __user *)arg;
615 struct gpiohandle_data ghd;
618 * We can get the value for an event line but not set it,
619 * because it is input by definition.
621 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
624 val = gpiod_get_value_cansleep(le->desc);
629 if (copy_to_user(ip, &ghd, sizeof(ghd)))
638 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
641 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
645 static const struct file_operations lineevent_fileops = {
646 .release = lineevent_release,
647 .read = lineevent_read,
648 .poll = lineevent_poll,
649 .owner = THIS_MODULE,
650 .llseek = noop_llseek,
651 .unlocked_ioctl = lineevent_ioctl,
653 .compat_ioctl = lineevent_ioctl_compat,
657 static irqreturn_t lineevent_irq_thread(int irq, void *p)
659 struct lineevent_state *le = p;
660 struct gpioevent_data ge;
663 ge.timestamp = ktime_get_real_ns();
665 if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
666 int level = gpiod_get_value_cansleep(le->desc);
669 /* Emit low-to-high event */
670 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
672 /* Emit high-to-low event */
673 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
674 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
675 /* Emit low-to-high event */
676 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
677 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
678 /* Emit high-to-low event */
679 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
684 ret = kfifo_put(&le->events, ge);
686 wake_up_poll(&le->wait, POLLIN);
691 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
693 struct gpioevent_request eventreq;
694 struct lineevent_state *le;
695 struct gpio_desc *desc;
703 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
706 le = kzalloc(sizeof(*le), GFP_KERNEL);
710 get_device(&gdev->dev);
712 /* Make sure this is terminated */
713 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
714 if (strlen(eventreq.consumer_label)) {
715 le->label = kstrdup(eventreq.consumer_label,
723 offset = eventreq.lineoffset;
724 lflags = eventreq.handleflags;
725 eflags = eventreq.eventflags;
727 /* This is just wrong: we don't look for events on output lines */
728 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
733 desc = &gdev->descs[offset];
734 ret = gpiod_request(desc, le->label);
740 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
741 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
742 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
743 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
744 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
745 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
747 ret = gpiod_direction_input(desc);
751 le->irq = gpiod_to_irq(desc);
757 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
758 irqflags |= IRQF_TRIGGER_RISING;
759 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
760 irqflags |= IRQF_TRIGGER_FALLING;
761 irqflags |= IRQF_ONESHOT;
762 irqflags |= IRQF_SHARED;
764 INIT_KFIFO(le->events);
765 init_waitqueue_head(&le->wait);
766 mutex_init(&le->read_lock);
768 /* Request a thread to read the events */
769 ret = request_threaded_irq(le->irq,
771 lineevent_irq_thread,
778 fd = anon_inode_getfd("gpio-event",
781 O_RDONLY | O_CLOEXEC);
788 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
796 free_irq(le->irq, le);
798 gpiod_free(le->desc);
803 put_device(&gdev->dev);
808 * gpio_ioctl() - ioctl handler for the GPIO chardev
810 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
812 struct gpio_device *gdev = filp->private_data;
813 struct gpio_chip *chip = gdev->chip;
814 void __user *ip = (void __user *)arg;
816 /* We fail any subsequent ioctl():s when the chip is gone */
820 /* Fill in the struct and pass to userspace */
821 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
822 struct gpiochip_info chipinfo;
824 strncpy(chipinfo.name, dev_name(&gdev->dev),
825 sizeof(chipinfo.name));
826 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
827 strncpy(chipinfo.label, gdev->label,
828 sizeof(chipinfo.label));
829 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
830 chipinfo.lines = gdev->ngpio;
831 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
834 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
835 struct gpioline_info lineinfo;
836 struct gpio_desc *desc;
838 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
840 if (lineinfo.line_offset > gdev->ngpio)
843 desc = &gdev->descs[lineinfo.line_offset];
845 strncpy(lineinfo.name, desc->name,
846 sizeof(lineinfo.name));
847 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
849 lineinfo.name[0] = '\0';
852 strncpy(lineinfo.consumer, desc->label,
853 sizeof(lineinfo.consumer));
854 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
856 lineinfo.consumer[0] = '\0';
860 * Userspace only need to know that the kernel is using
861 * this GPIO so it can't use it.
864 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
865 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
866 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
867 test_bit(FLAG_EXPORT, &desc->flags) ||
868 test_bit(FLAG_SYSFS, &desc->flags))
869 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
870 if (test_bit(FLAG_IS_OUT, &desc->flags))
871 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
872 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
873 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
874 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
875 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
876 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
877 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
879 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
882 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
883 return linehandle_create(gdev, ip);
884 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
885 return lineevent_create(gdev, ip);
891 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
894 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
899 * gpio_chrdev_open() - open the chardev for ioctl operations
900 * @inode: inode for this chardev
901 * @filp: file struct for storing private data
902 * Returns 0 on success
904 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
906 struct gpio_device *gdev = container_of(inode->i_cdev,
907 struct gpio_device, chrdev);
909 /* Fail on open if the backing gpiochip is gone */
910 if (!gdev || !gdev->chip)
912 get_device(&gdev->dev);
913 filp->private_data = gdev;
918 * gpio_chrdev_release() - close chardev after ioctl operations
919 * @inode: inode for this chardev
920 * @filp: file struct for storing private data
921 * Returns 0 on success
923 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
925 struct gpio_device *gdev = container_of(inode->i_cdev,
926 struct gpio_device, chrdev);
930 put_device(&gdev->dev);
935 static const struct file_operations gpio_fileops = {
936 .release = gpio_chrdev_release,
937 .open = gpio_chrdev_open,
938 .owner = THIS_MODULE,
939 .llseek = noop_llseek,
940 .unlocked_ioctl = gpio_ioctl,
942 .compat_ioctl = gpio_ioctl_compat,
946 static void gpiodevice_release(struct device *dev)
948 struct gpio_device *gdev = dev_get_drvdata(dev);
950 list_del(&gdev->list);
951 ida_simple_remove(&gpio_ida, gdev->id);
957 static int gpiochip_setup_dev(struct gpio_device *gdev)
961 cdev_init(&gdev->chrdev, &gpio_fileops);
962 gdev->chrdev.owner = THIS_MODULE;
963 gdev->chrdev.kobj.parent = &gdev->dev.kobj;
964 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
965 status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
967 chip_warn(gdev->chip, "failed to add char device %d:%d\n",
968 MAJOR(gpio_devt), gdev->id);
970 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
971 MAJOR(gpio_devt), gdev->id);
972 status = device_add(&gdev->dev);
974 goto err_remove_chardev;
976 status = gpiochip_sysfs_register(gdev);
978 goto err_remove_device;
980 /* From this point, the .release() function cleans up gpio_device */
981 gdev->dev.release = gpiodevice_release;
982 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
983 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
984 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
989 device_del(&gdev->dev);
991 cdev_del(&gdev->chrdev);
995 static void gpiochip_setup_devs(void)
997 struct gpio_device *gdev;
1000 list_for_each_entry(gdev, &gpio_devices, list) {
1001 err = gpiochip_setup_dev(gdev);
1003 pr_err("%s: Failed to initialize gpio device (%d)\n",
1004 dev_name(&gdev->dev), err);
1009 * gpiochip_add_data() - register a gpio_chip
1010 * @chip: the chip to register, with chip->base initialized
1011 * Context: potentially before irqs will work
1013 * Returns a negative errno if the chip can't be registered, such as
1014 * because the chip->base is invalid or already associated with a
1015 * different chip. Otherwise it returns zero as a success code.
1017 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1018 * can be freely used, the chip->parent device must be registered before
1019 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1020 * for GPIOs will fail rudely.
1022 * gpiochip_add_data() must only be called after gpiolib initialization,
1023 * ie after core_initcall().
1025 * If chip->base is negative, this requests dynamic assignment of
1026 * a range of valid GPIOs.
1028 int gpiochip_add_data(struct gpio_chip *chip, void *data)
1030 unsigned long flags;
1033 int base = chip->base;
1034 struct gpio_device *gdev;
1037 * First: allocate and populate the internal stat container, and
1038 * set up the struct device.
1040 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1043 gdev->dev.bus = &gpio_bus_type;
1045 chip->gpiodev = gdev;
1047 gdev->dev.parent = chip->parent;
1048 gdev->dev.of_node = chip->parent->of_node;
1051 #ifdef CONFIG_OF_GPIO
1052 /* If the gpiochip has an assigned OF node this takes precedence */
1054 gdev->dev.of_node = chip->of_node;
1057 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1062 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1063 device_initialize(&gdev->dev);
1064 dev_set_drvdata(&gdev->dev, gdev);
1065 if (chip->parent && chip->parent->driver)
1066 gdev->owner = chip->parent->driver->owner;
1067 else if (chip->owner)
1068 /* TODO: remove chip->owner */
1069 gdev->owner = chip->owner;
1071 gdev->owner = THIS_MODULE;
1073 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1079 if (chip->ngpio == 0) {
1080 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1082 goto err_free_descs;
1086 gdev->label = kstrdup(chip->label, GFP_KERNEL);
1088 gdev->label = kstrdup("unknown", GFP_KERNEL);
1091 goto err_free_descs;
1094 gdev->ngpio = chip->ngpio;
1097 spin_lock_irqsave(&gpio_lock, flags);
1100 * TODO: this allocates a Linux GPIO number base in the global
1101 * GPIO numberspace for this chip. In the long run we want to
1102 * get *rid* of this numberspace and use only descriptors, but
1103 * it may be a pipe dream. It will not happen before we get rid
1104 * of the sysfs interface anyways.
1107 base = gpiochip_find_base(chip->ngpio);
1110 spin_unlock_irqrestore(&gpio_lock, flags);
1111 goto err_free_label;
1114 * TODO: it should not be necessary to reflect the assigned
1115 * base outside of the GPIO subsystem. Go over drivers and
1116 * see if anyone makes use of this, else drop this and assign
1123 status = gpiodev_add_to_list(gdev);
1125 spin_unlock_irqrestore(&gpio_lock, flags);
1126 goto err_free_label;
1129 spin_unlock_irqrestore(&gpio_lock, flags);
1131 for (i = 0; i < chip->ngpio; i++) {
1132 struct gpio_desc *desc = &gdev->descs[i];
1136 * REVISIT: most hardware initializes GPIOs as inputs
1137 * (often with pullups enabled) so power usage is
1138 * minimized. Linux code should set the gpio direction
1139 * first thing; but until it does, and in case
1140 * chip->get_direction is not set, we may expose the
1141 * wrong direction in sysfs.
1144 if (chip->get_direction) {
1146 * If we have .get_direction, set up the initial
1147 * direction flag from the hardware.
1149 int dir = chip->get_direction(chip, i);
1152 set_bit(FLAG_IS_OUT, &desc->flags);
1153 } else if (!chip->direction_input) {
1155 * If the chip lacks the .direction_input callback
1156 * we logically assume all lines are outputs.
1158 set_bit(FLAG_IS_OUT, &desc->flags);
1162 #ifdef CONFIG_PINCTRL
1163 INIT_LIST_HEAD(&gdev->pin_ranges);
1166 status = gpiochip_set_desc_names(chip);
1168 goto err_remove_from_list;
1170 status = of_gpiochip_add(chip);
1172 goto err_remove_chip;
1174 acpi_gpiochip_add(chip);
1177 * By first adding the chardev, and then adding the device,
1178 * we get a device node entry in sysfs under
1179 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1180 * coldplug of device nodes and other udev business.
1181 * We can do this only if gpiolib has been initialized.
1182 * Otherwise, defer until later.
1184 if (gpiolib_initialized) {
1185 status = gpiochip_setup_dev(gdev);
1187 goto err_remove_chip;
1192 acpi_gpiochip_remove(chip);
1193 gpiochip_free_hogs(chip);
1194 of_gpiochip_remove(chip);
1195 err_remove_from_list:
1196 spin_lock_irqsave(&gpio_lock, flags);
1197 list_del(&gdev->list);
1198 spin_unlock_irqrestore(&gpio_lock, flags);
1204 ida_simple_remove(&gpio_ida, gdev->id);
1205 /* failures here can mean systems won't boot... */
1206 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1207 gdev->base, gdev->base + gdev->ngpio - 1,
1208 chip->label ? : "generic");
1212 EXPORT_SYMBOL_GPL(gpiochip_add_data);
1215 * gpiochip_get_data() - get per-subdriver data for the chip
1217 void *gpiochip_get_data(struct gpio_chip *chip)
1219 return chip->gpiodev->data;
1221 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1224 * gpiochip_remove() - unregister a gpio_chip
1225 * @chip: the chip to unregister
1227 * A gpio_chip with any GPIOs still requested may not be removed.
1229 void gpiochip_remove(struct gpio_chip *chip)
1231 struct gpio_device *gdev = chip->gpiodev;
1232 struct gpio_desc *desc;
1233 unsigned long flags;
1235 bool requested = false;
1237 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1238 gpiochip_sysfs_unregister(gdev);
1239 /* Numb the device, cancelling all outstanding operations */
1241 gpiochip_irqchip_remove(chip);
1242 acpi_gpiochip_remove(chip);
1243 gpiochip_remove_pin_ranges(chip);
1244 gpiochip_free_hogs(chip);
1245 of_gpiochip_remove(chip);
1247 * We accept no more calls into the driver from this point, so
1248 * NULL the driver data pointer
1252 spin_lock_irqsave(&gpio_lock, flags);
1253 for (i = 0; i < gdev->ngpio; i++) {
1254 desc = &gdev->descs[i];
1255 if (test_bit(FLAG_REQUESTED, &desc->flags))
1258 spin_unlock_irqrestore(&gpio_lock, flags);
1261 dev_crit(&gdev->dev,
1262 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1265 * The gpiochip side puts its use of the device to rest here:
1266 * if there are no userspace clients, the chardev and device will
1267 * be removed, else it will be dangling until the last user is
1270 cdev_del(&gdev->chrdev);
1271 device_del(&gdev->dev);
1272 put_device(&gdev->dev);
1274 EXPORT_SYMBOL_GPL(gpiochip_remove);
1276 static void devm_gpio_chip_release(struct device *dev, void *res)
1278 struct gpio_chip *chip = *(struct gpio_chip **)res;
1280 gpiochip_remove(chip);
1283 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1286 struct gpio_chip **r = res;
1297 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1298 * @dev: the device pointer on which irq_chip belongs to.
1299 * @chip: the chip to register, with chip->base initialized
1300 * Context: potentially before irqs will work
1302 * Returns a negative errno if the chip can't be registered, such as
1303 * because the chip->base is invalid or already associated with a
1304 * different chip. Otherwise it returns zero as a success code.
1306 * The gpio chip automatically be released when the device is unbound.
1308 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1311 struct gpio_chip **ptr;
1314 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1319 ret = gpiochip_add_data(chip, data);
1326 devres_add(dev, ptr);
1330 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1333 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1334 * @dev: device for which which resource was allocated
1335 * @chip: the chip to remove
1337 * A gpio_chip with any GPIOs still requested may not be removed.
1339 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1343 ret = devres_release(dev, devm_gpio_chip_release,
1344 devm_gpio_chip_match, chip);
1348 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1351 * gpiochip_find() - iterator for locating a specific gpio_chip
1352 * @data: data to pass to match function
1353 * @callback: Callback function to check gpio_chip
1355 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1356 * determined by a user supplied @match callback. The callback should return
1357 * 0 if the device doesn't match and non-zero if it does. If the callback is
1358 * non-zero, this function will return to the caller and not iterate over any
1361 struct gpio_chip *gpiochip_find(void *data,
1362 int (*match)(struct gpio_chip *chip,
1365 struct gpio_device *gdev;
1366 struct gpio_chip *chip = NULL;
1367 unsigned long flags;
1369 spin_lock_irqsave(&gpio_lock, flags);
1370 list_for_each_entry(gdev, &gpio_devices, list)
1371 if (gdev->chip && match(gdev->chip, data)) {
1376 spin_unlock_irqrestore(&gpio_lock, flags);
1380 EXPORT_SYMBOL_GPL(gpiochip_find);
1382 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1384 const char *name = data;
1386 return !strcmp(chip->label, name);
1389 static struct gpio_chip *find_chip_by_name(const char *name)
1391 return gpiochip_find((void *)name, gpiochip_match_name);
1394 #ifdef CONFIG_GPIOLIB_IRQCHIP
1397 * The following is irqchip helper code for gpiochips.
1401 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
1402 * @gpiochip: the gpiochip to set the irqchip chain to
1403 * @irqchip: the irqchip to chain to the gpiochip
1404 * @parent_irq: the irq number corresponding to the parent IRQ for this
1406 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1407 * coming out of the gpiochip. If the interrupt is nested rather than
1408 * cascaded, pass NULL in this handler argument
1410 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1411 struct irq_chip *irqchip,
1413 irq_flow_handler_t parent_handler)
1415 unsigned int offset;
1417 if (!gpiochip->irqdomain) {
1418 chip_err(gpiochip, "called %s before setting up irqchip\n",
1423 if (parent_handler) {
1424 if (gpiochip->can_sleep) {
1426 "you cannot have chained interrupts on a "
1427 "chip that may sleep\n");
1431 * The parent irqchip is already using the chip_data for this
1432 * irqchip, so our callbacks simply use the handler_data.
1434 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1437 gpiochip->irq_parent = parent_irq;
1440 /* Set the parent IRQ for all affected IRQs */
1441 for (offset = 0; offset < gpiochip->ngpio; offset++)
1442 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
1445 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1448 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1449 * @d: the irqdomain used by this irqchip
1450 * @irq: the global irq number used by this GPIO irqchip irq
1451 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1453 * This function will set up the mapping for a certain IRQ line on a
1454 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1455 * stored inside the gpiochip.
1457 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1458 irq_hw_number_t hwirq)
1460 struct gpio_chip *chip = d->host_data;
1462 irq_set_chip_data(irq, chip);
1464 * This lock class tells lockdep that GPIO irqs are in a different
1465 * category than their parents, so it won't report false recursion.
1467 irq_set_lockdep_class(irq, chip->lock_key);
1468 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1469 /* Chips that can sleep need nested thread handlers */
1470 if (chip->can_sleep && !chip->irq_not_threaded)
1471 irq_set_nested_thread(irq, 1);
1472 irq_set_noprobe(irq);
1475 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1476 * is passed as default type.
1478 if (chip->irq_default_type != IRQ_TYPE_NONE)
1479 irq_set_irq_type(irq, chip->irq_default_type);
1484 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1486 struct gpio_chip *chip = d->host_data;
1488 if (chip->can_sleep)
1489 irq_set_nested_thread(irq, 0);
1490 irq_set_chip_and_handler(irq, NULL, NULL);
1491 irq_set_chip_data(irq, NULL);
1494 static const struct irq_domain_ops gpiochip_domain_ops = {
1495 .map = gpiochip_irq_map,
1496 .unmap = gpiochip_irq_unmap,
1497 /* Virtually all GPIO irqchips are twocell:ed */
1498 .xlate = irq_domain_xlate_twocell,
1501 static int gpiochip_irq_reqres(struct irq_data *d)
1503 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1505 if (!try_module_get(chip->gpiodev->owner))
1508 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1510 "unable to lock HW IRQ %lu for IRQ\n",
1512 module_put(chip->gpiodev->owner);
1518 static void gpiochip_irq_relres(struct irq_data *d)
1520 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1522 gpiochip_unlock_as_irq(chip, d->hwirq);
1523 module_put(chip->gpiodev->owner);
1526 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1528 return irq_find_mapping(chip->irqdomain, offset);
1532 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1533 * @gpiochip: the gpiochip to remove the irqchip from
1535 * This is called only from gpiochip_remove()
1537 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1539 unsigned int offset;
1541 acpi_gpiochip_free_interrupts(gpiochip);
1543 if (gpiochip->irq_parent) {
1544 irq_set_chained_handler(gpiochip->irq_parent, NULL);
1545 irq_set_handler_data(gpiochip->irq_parent, NULL);
1548 /* Remove all IRQ mappings and delete the domain */
1549 if (gpiochip->irqdomain) {
1550 for (offset = 0; offset < gpiochip->ngpio; offset++)
1551 irq_dispose_mapping(
1552 irq_find_mapping(gpiochip->irqdomain, offset));
1553 irq_domain_remove(gpiochip->irqdomain);
1556 if (gpiochip->irqchip) {
1557 gpiochip->irqchip->irq_request_resources = NULL;
1558 gpiochip->irqchip->irq_release_resources = NULL;
1559 gpiochip->irqchip = NULL;
1564 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1565 * @gpiochip: the gpiochip to add the irqchip to
1566 * @irqchip: the irqchip to add to the gpiochip
1567 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1568 * allocate gpiochip irqs from
1569 * @handler: the irq handler to use (often a predefined irq core function)
1570 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1571 * to have the core avoid setting up any default type in the hardware.
1572 * @lock_key: lockdep class
1574 * This function closely associates a certain irqchip with a certain
1575 * gpiochip, providing an irq domain to translate the local IRQs to
1576 * global irqs in the gpiolib core, and making sure that the gpiochip
1577 * is passed as chip data to all related functions. Driver callbacks
1578 * need to use gpiochip_get_data() to get their local state containers back
1579 * from the gpiochip passed as chip data. An irqdomain will be stored
1580 * in the gpiochip that shall be used by the driver to handle IRQ number
1581 * translation. The gpiochip will need to be initialized and registered
1582 * before calling this function.
1584 * This function will handle two cell:ed simple IRQs and assumes all
1585 * the pins on the gpiochip can generate a unique IRQ. Everything else
1586 * need to be open coded.
1588 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1589 struct irq_chip *irqchip,
1590 unsigned int first_irq,
1591 irq_flow_handler_t handler,
1593 struct lock_class_key *lock_key)
1595 struct device_node *of_node;
1596 unsigned int offset;
1597 unsigned irq_base = 0;
1599 if (!gpiochip || !irqchip)
1602 if (!gpiochip->parent) {
1603 pr_err("missing gpiochip .dev parent pointer\n");
1606 of_node = gpiochip->parent->of_node;
1607 #ifdef CONFIG_OF_GPIO
1609 * If the gpiochip has an assigned OF node this takes precedence
1610 * FIXME: get rid of this and use gpiochip->parent->of_node
1613 if (gpiochip->of_node)
1614 of_node = gpiochip->of_node;
1616 gpiochip->irqchip = irqchip;
1617 gpiochip->irq_handler = handler;
1618 gpiochip->irq_default_type = type;
1619 gpiochip->to_irq = gpiochip_to_irq;
1620 gpiochip->lock_key = lock_key;
1621 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1622 gpiochip->ngpio, first_irq,
1623 &gpiochip_domain_ops, gpiochip);
1624 if (!gpiochip->irqdomain) {
1625 gpiochip->irqchip = NULL;
1630 * It is possible for a driver to override this, but only if the
1631 * alternative functions are both implemented.
1633 if (!irqchip->irq_request_resources &&
1634 !irqchip->irq_release_resources) {
1635 irqchip->irq_request_resources = gpiochip_irq_reqres;
1636 irqchip->irq_release_resources = gpiochip_irq_relres;
1640 * Prepare the mapping since the irqchip shall be orthogonal to
1641 * any gpiochip calls. If the first_irq was zero, this is
1642 * necessary to allocate descriptors for all IRQs.
1644 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1645 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1648 * Store the base into the gpiochip to be used when
1649 * unmapping the irqs.
1651 gpiochip->irq_base = irq_base;
1654 acpi_gpiochip_request_interrupts(gpiochip);
1658 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
1660 #else /* CONFIG_GPIOLIB_IRQCHIP */
1662 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1664 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1667 * gpiochip_generic_request() - request the gpio function for a pin
1668 * @chip: the gpiochip owning the GPIO
1669 * @offset: the offset of the GPIO to request for GPIO function
1671 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1673 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1675 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1678 * gpiochip_generic_free() - free the gpio function from a pin
1679 * @chip: the gpiochip to request the gpio function for
1680 * @offset: the offset of the GPIO to free from GPIO function
1682 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1684 pinctrl_free_gpio(chip->gpiodev->base + offset);
1686 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1688 #ifdef CONFIG_PINCTRL
1691 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1692 * @chip: the gpiochip to add the range for
1693 * @pctldev: the pin controller to map to
1694 * @gpio_offset: the start offset in the current gpio_chip number space
1695 * @pin_group: name of the pin group inside the pin controller
1697 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1698 struct pinctrl_dev *pctldev,
1699 unsigned int gpio_offset, const char *pin_group)
1701 struct gpio_pin_range *pin_range;
1702 struct gpio_device *gdev = chip->gpiodev;
1705 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1707 chip_err(chip, "failed to allocate pin ranges\n");
1711 /* Use local offset as range ID */
1712 pin_range->range.id = gpio_offset;
1713 pin_range->range.gc = chip;
1714 pin_range->range.name = chip->label;
1715 pin_range->range.base = gdev->base + gpio_offset;
1716 pin_range->pctldev = pctldev;
1718 ret = pinctrl_get_group_pins(pctldev, pin_group,
1719 &pin_range->range.pins,
1720 &pin_range->range.npins);
1726 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1728 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1729 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1730 pinctrl_dev_get_devname(pctldev), pin_group);
1732 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1736 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1739 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1740 * @chip: the gpiochip to add the range for
1741 * @pinctrl_name: the dev_name() of the pin controller to map to
1742 * @gpio_offset: the start offset in the current gpio_chip number space
1743 * @pin_offset: the start offset in the pin controller number space
1744 * @npins: the number of pins from the offset of each pin space (GPIO and
1745 * pin controller) to accumulate in this range
1747 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1748 unsigned int gpio_offset, unsigned int pin_offset,
1751 struct gpio_pin_range *pin_range;
1752 struct gpio_device *gdev = chip->gpiodev;
1755 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1757 chip_err(chip, "failed to allocate pin ranges\n");
1761 /* Use local offset as range ID */
1762 pin_range->range.id = gpio_offset;
1763 pin_range->range.gc = chip;
1764 pin_range->range.name = chip->label;
1765 pin_range->range.base = gdev->base + gpio_offset;
1766 pin_range->range.pin_base = pin_offset;
1767 pin_range->range.npins = npins;
1768 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1770 if (IS_ERR(pin_range->pctldev)) {
1771 ret = PTR_ERR(pin_range->pctldev);
1772 chip_err(chip, "could not create pin range\n");
1776 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1777 gpio_offset, gpio_offset + npins - 1,
1779 pin_offset, pin_offset + npins - 1);
1781 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1785 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1788 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1789 * @chip: the chip to remove all the mappings for
1791 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1793 struct gpio_pin_range *pin_range, *tmp;
1794 struct gpio_device *gdev = chip->gpiodev;
1796 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1797 list_del(&pin_range->node);
1798 pinctrl_remove_gpio_range(pin_range->pctldev,
1803 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1805 #endif /* CONFIG_PINCTRL */
1807 /* These "optional" allocation calls help prevent drivers from stomping
1808 * on each other, and help provide better diagnostics in debugfs.
1809 * They're called even less than the "set direction" calls.
1811 static int __gpiod_request(struct gpio_desc *desc, const char *label)
1813 struct gpio_chip *chip = desc->gdev->chip;
1815 unsigned long flags;
1817 spin_lock_irqsave(&gpio_lock, flags);
1819 /* NOTE: gpio_request() can be called in early boot,
1820 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1823 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1824 desc_set_label(desc, label ? : "?");
1831 if (chip->request) {
1832 /* chip->request may sleep */
1833 spin_unlock_irqrestore(&gpio_lock, flags);
1834 status = chip->request(chip, gpio_chip_hwgpio(desc));
1835 spin_lock_irqsave(&gpio_lock, flags);
1838 desc_set_label(desc, NULL);
1839 clear_bit(FLAG_REQUESTED, &desc->flags);
1843 if (chip->get_direction) {
1844 /* chip->get_direction may sleep */
1845 spin_unlock_irqrestore(&gpio_lock, flags);
1846 gpiod_get_direction(desc);
1847 spin_lock_irqsave(&gpio_lock, flags);
1850 spin_unlock_irqrestore(&gpio_lock, flags);
1855 * This descriptor validation needs to be inserted verbatim into each
1856 * function taking a descriptor, so we need to use a preprocessor
1857 * macro to avoid endless duplication. If the desc is NULL it is an
1858 * optional GPIO and calls should just bail out.
1860 #define VALIDATE_DESC(desc) do { \
1863 if (IS_ERR(desc)) { \
1864 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1865 return PTR_ERR(desc); \
1867 if (!desc->gdev) { \
1868 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1871 if ( !desc->gdev->chip ) { \
1872 dev_warn(&desc->gdev->dev, \
1873 "%s: backing chip is gone\n", __func__); \
1877 #define VALIDATE_DESC_VOID(desc) do { \
1880 if (IS_ERR(desc)) { \
1881 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1884 if (!desc->gdev) { \
1885 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1888 if (!desc->gdev->chip) { \
1889 dev_warn(&desc->gdev->dev, \
1890 "%s: backing chip is gone\n", __func__); \
1895 int gpiod_request(struct gpio_desc *desc, const char *label)
1897 int status = -EPROBE_DEFER;
1898 struct gpio_device *gdev;
1900 VALIDATE_DESC(desc);
1903 if (try_module_get(gdev->owner)) {
1904 status = __gpiod_request(desc, label);
1906 module_put(gdev->owner);
1908 get_device(&gdev->dev);
1912 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
1917 static bool __gpiod_free(struct gpio_desc *desc)
1920 unsigned long flags;
1921 struct gpio_chip *chip;
1925 gpiod_unexport(desc);
1927 spin_lock_irqsave(&gpio_lock, flags);
1929 chip = desc->gdev->chip;
1930 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1932 spin_unlock_irqrestore(&gpio_lock, flags);
1933 might_sleep_if(chip->can_sleep);
1934 chip->free(chip, gpio_chip_hwgpio(desc));
1935 spin_lock_irqsave(&gpio_lock, flags);
1937 desc_set_label(desc, NULL);
1938 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1939 clear_bit(FLAG_REQUESTED, &desc->flags);
1940 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1941 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1942 clear_bit(FLAG_IS_HOGGED, &desc->flags);
1946 spin_unlock_irqrestore(&gpio_lock, flags);
1950 void gpiod_free(struct gpio_desc *desc)
1952 if (desc && desc->gdev && __gpiod_free(desc)) {
1953 module_put(desc->gdev->owner);
1954 put_device(&desc->gdev->dev);
1956 WARN_ON(extra_checks);
1961 * gpiochip_is_requested - return string iff signal was requested
1962 * @chip: controller managing the signal
1963 * @offset: of signal within controller's 0..(ngpio - 1) range
1965 * Returns NULL if the GPIO is not currently requested, else a string.
1966 * The string returned is the label passed to gpio_request(); if none has been
1967 * passed it is a meaningless, non-NULL constant.
1969 * This function is for use by GPIO controller drivers. The label can
1970 * help with diagnostics, and knowing that the signal is used as a GPIO
1971 * can help avoid accidentally multiplexing it to another controller.
1973 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1975 struct gpio_desc *desc;
1977 if (offset >= chip->ngpio)
1980 desc = &chip->gpiodev->descs[offset];
1982 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
1986 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1989 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1990 * @desc: GPIO descriptor to request
1991 * @label: label for the GPIO
1993 * Function allows GPIO chip drivers to request and use their own GPIO
1994 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1995 * function will not increase reference count of the GPIO chip module. This
1996 * allows the GPIO chip module to be unloaded as needed (we assume that the
1997 * GPIO chip driver handles freeing the GPIOs it has requested).
1999 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2002 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2006 chip_err(chip, "failed to get GPIO descriptor\n");
2010 err = __gpiod_request(desc, label);
2012 return ERR_PTR(err);
2016 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2019 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2020 * @desc: GPIO descriptor to free
2022 * Function frees the given GPIO requested previously with
2023 * gpiochip_request_own_desc().
2025 void gpiochip_free_own_desc(struct gpio_desc *desc)
2030 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2033 * Drivers MUST set GPIO direction before making get/set calls. In
2034 * some cases this is done in early boot, before IRQs are enabled.
2036 * As a rule these aren't called more than once (except for drivers
2037 * using the open-drain emulation idiom) so these are natural places
2038 * to accumulate extra debugging checks. Note that we can't (yet)
2039 * rely on gpio_request() having been called beforehand.
2043 * gpiod_direction_input - set the GPIO direction to input
2044 * @desc: GPIO to set to input
2046 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2047 * be called safely on it.
2049 * Return 0 in case of success, else an error code.
2051 int gpiod_direction_input(struct gpio_desc *desc)
2053 struct gpio_chip *chip;
2054 int status = -EINVAL;
2056 VALIDATE_DESC(desc);
2057 chip = desc->gdev->chip;
2059 if (!chip->get || !chip->direction_input) {
2061 "%s: missing get() or direction_input() operations\n",
2066 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2068 clear_bit(FLAG_IS_OUT, &desc->flags);
2070 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2074 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2076 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2078 struct gpio_chip *gc = desc->gdev->chip;
2081 /* GPIOs used for IRQs shall not be set as output */
2082 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2084 "%s: tried to set a GPIO tied to an IRQ as output\n",
2089 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2090 /* First see if we can enable open drain in hardware */
2091 if (gc->set_single_ended) {
2092 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2093 LINE_MODE_OPEN_DRAIN);
2095 goto set_output_value;
2097 /* Emulate open drain by not actively driving the line high */
2099 return gpiod_direction_input(desc);
2101 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2102 if (gc->set_single_ended) {
2103 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2104 LINE_MODE_OPEN_SOURCE);
2106 goto set_output_value;
2108 /* Emulate open source by not actively driving the line low */
2110 return gpiod_direction_input(desc);
2112 /* Make sure to disable open drain/source hardware, if any */
2113 if (gc->set_single_ended)
2114 gc->set_single_ended(gc,
2115 gpio_chip_hwgpio(desc),
2116 LINE_MODE_PUSH_PULL);
2120 if (!gc->set || !gc->direction_output) {
2122 "%s: missing set() or direction_output() operations\n",
2127 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
2129 set_bit(FLAG_IS_OUT, &desc->flags);
2130 trace_gpio_value(desc_to_gpio(desc), 0, value);
2131 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2136 * gpiod_direction_output_raw - set the GPIO direction to output
2137 * @desc: GPIO to set to output
2138 * @value: initial output value of the GPIO
2140 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2141 * be called safely on it. The initial value of the output must be specified
2142 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2144 * Return 0 in case of success, else an error code.
2146 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2148 VALIDATE_DESC(desc);
2149 return _gpiod_direction_output_raw(desc, value);
2151 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2154 * gpiod_direction_output - set the GPIO direction to output
2155 * @desc: GPIO to set to output
2156 * @value: initial output value of the GPIO
2158 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2159 * be called safely on it. The initial value of the output must be specified
2160 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2163 * Return 0 in case of success, else an error code.
2165 int gpiod_direction_output(struct gpio_desc *desc, int value)
2167 VALIDATE_DESC(desc);
2168 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2170 return _gpiod_direction_output_raw(desc, value);
2172 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2175 * gpiod_set_debounce - sets @debounce time for a @gpio
2176 * @gpio: the gpio to set debounce time
2177 * @debounce: debounce time is microseconds
2179 * returns -ENOTSUPP if the controller does not support setting
2182 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2184 struct gpio_chip *chip;
2186 VALIDATE_DESC(desc);
2187 chip = desc->gdev->chip;
2188 if (!chip->set || !chip->set_debounce) {
2190 "%s: missing set() or set_debounce() operations\n",
2195 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
2197 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2200 * gpiod_is_active_low - test whether a GPIO is active-low or not
2201 * @desc: the gpio descriptor to test
2203 * Returns 1 if the GPIO is active-low, 0 otherwise.
2205 int gpiod_is_active_low(const struct gpio_desc *desc)
2207 VALIDATE_DESC(desc);
2208 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2210 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2212 /* I/O calls are only valid after configuration completed; the relevant
2213 * "is this a valid GPIO" error checks should already have been done.
2215 * "Get" operations are often inlinable as reading a pin value register,
2216 * and masking the relevant bit in that register.
2218 * When "set" operations are inlinable, they involve writing that mask to
2219 * one register to set a low value, or a different register to set it high.
2220 * Otherwise locking is needed, so there may be little value to inlining.
2222 *------------------------------------------------------------------------
2224 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2225 * have requested the GPIO. That can include implicit requesting by
2226 * a direction setting call. Marking a gpio as requested locks its chip
2227 * in memory, guaranteeing that these table lookups need no more locking
2228 * and that gpiochip_remove() will fail.
2230 * REVISIT when debugging, consider adding some instrumentation to ensure
2231 * that the GPIO was actually requested.
2234 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
2236 struct gpio_chip *chip;
2240 chip = desc->gdev->chip;
2241 offset = gpio_chip_hwgpio(desc);
2242 value = chip->get ? chip->get(chip, offset) : -EIO;
2243 value = value < 0 ? value : !!value;
2244 trace_gpio_value(desc_to_gpio(desc), 1, value);
2249 * gpiod_get_raw_value() - return a gpio's raw value
2250 * @desc: gpio whose value will be returned
2252 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2253 * its ACTIVE_LOW status, or negative errno on failure.
2255 * This function should be called from contexts where we cannot sleep, and will
2256 * complain if the GPIO chip functions potentially sleep.
2258 int gpiod_get_raw_value(const struct gpio_desc *desc)
2260 VALIDATE_DESC(desc);
2261 /* Should be using gpio_get_value_cansleep() */
2262 WARN_ON(desc->gdev->chip->can_sleep);
2263 return _gpiod_get_raw_value(desc);
2265 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2268 * gpiod_get_value() - return a gpio's value
2269 * @desc: gpio whose value will be returned
2271 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2272 * account, or negative errno on failure.
2274 * This function should be called from contexts where we cannot sleep, and will
2275 * complain if the GPIO chip functions potentially sleep.
2277 int gpiod_get_value(const struct gpio_desc *desc)
2281 VALIDATE_DESC(desc);
2282 /* Should be using gpio_get_value_cansleep() */
2283 WARN_ON(desc->gdev->chip->can_sleep);
2285 value = _gpiod_get_raw_value(desc);
2289 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2294 EXPORT_SYMBOL_GPL(gpiod_get_value);
2297 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2298 * @desc: gpio descriptor whose state need to be set.
2299 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2301 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2304 struct gpio_chip *chip = desc->gdev->chip;
2305 int offset = gpio_chip_hwgpio(desc);
2308 err = chip->direction_input(chip, offset);
2310 clear_bit(FLAG_IS_OUT, &desc->flags);
2312 err = chip->direction_output(chip, offset, 0);
2314 set_bit(FLAG_IS_OUT, &desc->flags);
2316 trace_gpio_direction(desc_to_gpio(desc), value, err);
2319 "%s: Error in set_value for open drain err %d\n",
2324 * _gpio_set_open_source_value() - Set the open source gpio's value.
2325 * @desc: gpio descriptor whose state need to be set.
2326 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2328 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2331 struct gpio_chip *chip = desc->gdev->chip;
2332 int offset = gpio_chip_hwgpio(desc);
2335 err = chip->direction_output(chip, offset, 1);
2337 set_bit(FLAG_IS_OUT, &desc->flags);
2339 err = chip->direction_input(chip, offset);
2341 clear_bit(FLAG_IS_OUT, &desc->flags);
2343 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2346 "%s: Error in set_value for open source err %d\n",
2350 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2352 struct gpio_chip *chip;
2354 chip = desc->gdev->chip;
2355 trace_gpio_value(desc_to_gpio(desc), 0, value);
2356 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2357 _gpio_set_open_drain_value(desc, value);
2358 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2359 _gpio_set_open_source_value(desc, value);
2361 chip->set(chip, gpio_chip_hwgpio(desc), value);
2365 * set multiple outputs on the same chip;
2366 * use the chip's set_multiple function if available;
2367 * otherwise set the outputs sequentially;
2368 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2369 * defines which outputs are to be changed
2370 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2371 * defines the values the outputs specified by mask are to be set to
2373 static void gpio_chip_set_multiple(struct gpio_chip *chip,
2374 unsigned long *mask, unsigned long *bits)
2376 if (chip->set_multiple) {
2377 chip->set_multiple(chip, mask, bits);
2380 for (i = 0; i < chip->ngpio; i++) {
2381 if (mask[BIT_WORD(i)] == 0) {
2382 /* no more set bits in this mask word;
2383 * skip ahead to the next word */
2384 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
2387 /* set outputs if the corresponding mask bit is set */
2388 if (__test_and_clear_bit(i, mask))
2389 chip->set(chip, i, test_bit(i, bits));
2394 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2395 unsigned int array_size,
2396 struct gpio_desc **desc_array,
2401 while (i < array_size) {
2402 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2403 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2404 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2408 WARN_ON(chip->can_sleep);
2410 memset(mask, 0, sizeof(mask));
2412 struct gpio_desc *desc = desc_array[i];
2413 int hwgpio = gpio_chip_hwgpio(desc);
2414 int value = value_array[i];
2416 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2418 trace_gpio_value(desc_to_gpio(desc), 0, value);
2420 * collect all normal outputs belonging to the same chip
2421 * open drain and open source outputs are set individually
2423 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2424 _gpio_set_open_drain_value(desc, value);
2425 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2426 _gpio_set_open_source_value(desc, value);
2428 __set_bit(hwgpio, mask);
2430 __set_bit(hwgpio, bits);
2432 __clear_bit(hwgpio, bits);
2436 } while ((i < array_size) &&
2437 (desc_array[i]->gdev->chip == chip));
2438 /* push collected bits to outputs */
2440 gpio_chip_set_multiple(chip, mask, bits);
2445 * gpiod_set_raw_value() - assign a gpio's raw value
2446 * @desc: gpio whose value will be assigned
2447 * @value: value to assign
2449 * Set the raw value of the GPIO, i.e. the value of its physical line without
2450 * regard for its ACTIVE_LOW status.
2452 * This function should be called from contexts where we cannot sleep, and will
2453 * complain if the GPIO chip functions potentially sleep.
2455 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2457 VALIDATE_DESC_VOID(desc);
2458 /* Should be using gpiod_set_value_cansleep() */
2459 WARN_ON(desc->gdev->chip->can_sleep);
2460 _gpiod_set_raw_value(desc, value);
2462 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2465 * gpiod_set_value() - assign a gpio's value
2466 * @desc: gpio whose value will be assigned
2467 * @value: value to assign
2469 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2472 * This function should be called from contexts where we cannot sleep, and will
2473 * complain if the GPIO chip functions potentially sleep.
2475 void gpiod_set_value(struct gpio_desc *desc, int value)
2477 VALIDATE_DESC_VOID(desc);
2478 /* Should be using gpiod_set_value_cansleep() */
2479 WARN_ON(desc->gdev->chip->can_sleep);
2480 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2482 _gpiod_set_raw_value(desc, value);
2484 EXPORT_SYMBOL_GPL(gpiod_set_value);
2487 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2488 * @array_size: number of elements in the descriptor / value arrays
2489 * @desc_array: array of GPIO descriptors whose values will be assigned
2490 * @value_array: array of values to assign
2492 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2493 * without regard for their ACTIVE_LOW status.
2495 * This function should be called from contexts where we cannot sleep, and will
2496 * complain if the GPIO chip functions potentially sleep.
2498 void gpiod_set_raw_array_value(unsigned int array_size,
2499 struct gpio_desc **desc_array, int *value_array)
2503 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2506 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2509 * gpiod_set_array_value() - assign values to an array of GPIOs
2510 * @array_size: number of elements in the descriptor / value arrays
2511 * @desc_array: array of GPIO descriptors whose values will be assigned
2512 * @value_array: array of values to assign
2514 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2517 * This function should be called from contexts where we cannot sleep, and will
2518 * complain if the GPIO chip functions potentially sleep.
2520 void gpiod_set_array_value(unsigned int array_size,
2521 struct gpio_desc **desc_array, int *value_array)
2525 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2528 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2531 * gpiod_cansleep() - report whether gpio value access may sleep
2532 * @desc: gpio to check
2535 int gpiod_cansleep(const struct gpio_desc *desc)
2537 VALIDATE_DESC(desc);
2538 return desc->gdev->chip->can_sleep;
2540 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2543 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2544 * @desc: gpio whose IRQ will be returned (already requested)
2546 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2549 int gpiod_to_irq(const struct gpio_desc *desc)
2551 struct gpio_chip *chip;
2555 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2556 * requires this function to not return zero on an invalid descriptor
2557 * but rather a negative error number.
2559 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2562 chip = desc->gdev->chip;
2563 offset = gpio_chip_hwgpio(desc);
2565 int retirq = chip->to_irq(chip, offset);
2567 /* Zero means NO_IRQ */
2575 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2578 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2579 * @chip: the chip the GPIO to lock belongs to
2580 * @offset: the offset of the GPIO to lock as IRQ
2582 * This is used directly by GPIO drivers that want to lock down
2583 * a certain GPIO line to be used for IRQs.
2585 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2587 struct gpio_desc *desc;
2589 desc = gpiochip_get_desc(chip, offset);
2591 return PTR_ERR(desc);
2593 /* Flush direction if something changed behind our back */
2594 if (chip->get_direction) {
2595 int dir = chip->get_direction(chip, offset);
2598 clear_bit(FLAG_IS_OUT, &desc->flags);
2600 set_bit(FLAG_IS_OUT, &desc->flags);
2603 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2605 "%s: tried to flag a GPIO set as output for IRQ\n",
2610 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2613 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2616 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2617 * @chip: the chip the GPIO to lock belongs to
2618 * @offset: the offset of the GPIO to lock as IRQ
2620 * This is used directly by GPIO drivers that want to indicate
2621 * that a certain GPIO is no longer used exclusively for IRQ.
2623 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2625 if (offset >= chip->ngpio)
2628 clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2630 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2632 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2634 if (offset >= chip->ngpio)
2637 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2639 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2641 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2643 if (offset >= chip->ngpio)
2646 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2648 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2650 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2652 if (offset >= chip->ngpio)
2655 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2657 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2660 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2661 * @desc: gpio whose value will be returned
2663 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2664 * its ACTIVE_LOW status, or negative errno on failure.
2666 * This function is to be called from contexts that can sleep.
2668 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2670 might_sleep_if(extra_checks);
2671 VALIDATE_DESC(desc);
2672 return _gpiod_get_raw_value(desc);
2674 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2677 * gpiod_get_value_cansleep() - return a gpio's value
2678 * @desc: gpio whose value will be returned
2680 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2681 * account, or negative errno on failure.
2683 * This function is to be called from contexts that can sleep.
2685 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2689 might_sleep_if(extra_checks);
2690 VALIDATE_DESC(desc);
2691 value = _gpiod_get_raw_value(desc);
2695 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2700 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2703 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2704 * @desc: gpio whose value will be assigned
2705 * @value: value to assign
2707 * Set the raw value of the GPIO, i.e. the value of its physical line without
2708 * regard for its ACTIVE_LOW status.
2710 * This function is to be called from contexts that can sleep.
2712 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2714 might_sleep_if(extra_checks);
2715 VALIDATE_DESC_VOID(desc);
2716 _gpiod_set_raw_value(desc, value);
2718 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2721 * gpiod_set_value_cansleep() - assign a gpio's value
2722 * @desc: gpio whose value will be assigned
2723 * @value: value to assign
2725 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2728 * This function is to be called from contexts that can sleep.
2730 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2732 might_sleep_if(extra_checks);
2733 VALIDATE_DESC_VOID(desc);
2734 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2736 _gpiod_set_raw_value(desc, value);
2738 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2741 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2742 * @array_size: number of elements in the descriptor / value arrays
2743 * @desc_array: array of GPIO descriptors whose values will be assigned
2744 * @value_array: array of values to assign
2746 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2747 * without regard for their ACTIVE_LOW status.
2749 * This function is to be called from contexts that can sleep.
2751 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2752 struct gpio_desc **desc_array,
2755 might_sleep_if(extra_checks);
2758 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2761 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2764 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2765 * @array_size: number of elements in the descriptor / value arrays
2766 * @desc_array: array of GPIO descriptors whose values will be assigned
2767 * @value_array: array of values to assign
2769 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2772 * This function is to be called from contexts that can sleep.
2774 void gpiod_set_array_value_cansleep(unsigned int array_size,
2775 struct gpio_desc **desc_array,
2778 might_sleep_if(extra_checks);
2781 gpiod_set_array_value_complex(false, true, array_size, desc_array,
2784 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
2787 * gpiod_add_lookup_table() - register GPIO device consumers
2788 * @table: table of consumers to register
2790 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2792 mutex_lock(&gpio_lookup_lock);
2794 list_add_tail(&table->list, &gpio_lookup_list);
2796 mutex_unlock(&gpio_lookup_lock);
2800 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2801 * @table: table of consumers to unregister
2803 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
2805 mutex_lock(&gpio_lookup_lock);
2807 list_del(&table->list);
2809 mutex_unlock(&gpio_lookup_lock);
2812 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
2814 enum gpio_lookup_flags *flags)
2816 char prop_name[32]; /* 32 is max size of property name */
2817 enum of_gpio_flags of_flags;
2818 struct gpio_desc *desc;
2821 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2823 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
2826 snprintf(prop_name, sizeof(prop_name), "%s",
2829 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
2831 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
2838 if (of_flags & OF_GPIO_ACTIVE_LOW)
2839 *flags |= GPIO_ACTIVE_LOW;
2841 if (of_flags & OF_GPIO_SINGLE_ENDED) {
2842 if (of_flags & OF_GPIO_ACTIVE_LOW)
2843 *flags |= GPIO_OPEN_DRAIN;
2845 *flags |= GPIO_OPEN_SOURCE;
2851 static struct gpio_desc *acpi_find_gpio(struct device *dev,
2854 enum gpiod_flags flags,
2855 enum gpio_lookup_flags *lookupflags)
2857 struct acpi_device *adev = ACPI_COMPANION(dev);
2858 struct acpi_gpio_info info;
2859 struct gpio_desc *desc;
2863 /* Try first from _DSD */
2864 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2865 if (con_id && strcmp(con_id, "gpios")) {
2866 snprintf(propname, sizeof(propname), "%s-%s",
2867 con_id, gpio_suffixes[i]);
2869 snprintf(propname, sizeof(propname), "%s",
2873 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
2874 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
2878 /* Then from plain _CRS GPIOs */
2880 if (!acpi_can_fallback_to_crs(adev, con_id))
2881 return ERR_PTR(-ENOENT);
2883 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
2887 if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
2889 dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
2890 return ERR_PTR(-ENOENT);
2894 if (info.polarity == GPIO_ACTIVE_LOW)
2895 *lookupflags |= GPIO_ACTIVE_LOW;
2900 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2902 const char *dev_id = dev ? dev_name(dev) : NULL;
2903 struct gpiod_lookup_table *table;
2905 mutex_lock(&gpio_lookup_lock);
2907 list_for_each_entry(table, &gpio_lookup_list, list) {
2908 if (table->dev_id && dev_id) {
2910 * Valid strings on both ends, must be identical to have
2913 if (!strcmp(table->dev_id, dev_id))
2917 * One of the pointers is NULL, so both must be to have
2920 if (dev_id == table->dev_id)
2927 mutex_unlock(&gpio_lookup_lock);
2931 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2933 enum gpio_lookup_flags *flags)
2935 struct gpio_desc *desc = ERR_PTR(-ENOENT);
2936 struct gpiod_lookup_table *table;
2937 struct gpiod_lookup *p;
2939 table = gpiod_find_lookup_table(dev);
2943 for (p = &table->table[0]; p->chip_label; p++) {
2944 struct gpio_chip *chip;
2946 /* idx must always match exactly */
2950 /* If the lookup entry has a con_id, require exact match */
2951 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2954 chip = find_chip_by_name(p->chip_label);
2957 dev_err(dev, "cannot find GPIO chip %s\n",
2959 return ERR_PTR(-ENODEV);
2962 if (chip->ngpio <= p->chip_hwnum) {
2964 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2965 idx, chip->ngpio, chip->label);
2966 return ERR_PTR(-EINVAL);
2969 desc = gpiochip_get_desc(chip, p->chip_hwnum);
2978 static int dt_gpio_count(struct device *dev, const char *con_id)
2984 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2986 snprintf(propname, sizeof(propname), "%s-%s",
2987 con_id, gpio_suffixes[i]);
2989 snprintf(propname, sizeof(propname), "%s",
2992 ret = of_gpio_named_count(dev->of_node, propname);
2999 static int platform_gpio_count(struct device *dev, const char *con_id)
3001 struct gpiod_lookup_table *table;
3002 struct gpiod_lookup *p;
3003 unsigned int count = 0;
3005 table = gpiod_find_lookup_table(dev);
3009 for (p = &table->table[0]; p->chip_label; p++) {
3010 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3011 (!con_id && !p->con_id))
3021 * gpiod_count - return the number of GPIOs associated with a device / function
3022 * or -ENOENT if no GPIO has been assigned to the requested function
3023 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3024 * @con_id: function within the GPIO consumer
3026 int gpiod_count(struct device *dev, const char *con_id)
3028 int count = -ENOENT;
3030 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3031 count = dt_gpio_count(dev, con_id);
3032 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3033 count = acpi_gpio_count(dev, con_id);
3036 count = platform_gpio_count(dev, con_id);
3040 EXPORT_SYMBOL_GPL(gpiod_count);
3043 * gpiod_get - obtain a GPIO for a given GPIO function
3044 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3045 * @con_id: function within the GPIO consumer
3046 * @flags: optional GPIO initialization flags
3048 * Return the GPIO descriptor corresponding to the function con_id of device
3049 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3050 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3052 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3053 enum gpiod_flags flags)
3055 return gpiod_get_index(dev, con_id, 0, flags);
3057 EXPORT_SYMBOL_GPL(gpiod_get);
3060 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3061 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3062 * @con_id: function within the GPIO consumer
3063 * @flags: optional GPIO initialization flags
3065 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3066 * the requested function it will return NULL. This is convenient for drivers
3067 * that need to handle optional GPIOs.
3069 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3071 enum gpiod_flags flags)
3073 return gpiod_get_index_optional(dev, con_id, 0, flags);
3075 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3079 * gpiod_configure_flags - helper function to configure a given GPIO
3080 * @desc: gpio whose value will be assigned
3081 * @con_id: function within the GPIO consumer
3082 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3084 * @dflags: gpiod_flags - optional GPIO initialization flags
3086 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3087 * requested function and/or index, or another IS_ERR() code if an error
3088 * occurred while trying to acquire the GPIO.
3090 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3091 unsigned long lflags, enum gpiod_flags dflags)
3095 if (lflags & GPIO_ACTIVE_LOW)
3096 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3097 if (lflags & GPIO_OPEN_DRAIN)
3098 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3099 if (lflags & GPIO_OPEN_SOURCE)
3100 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3102 /* No particular flag request, return here... */
3103 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3104 pr_debug("no flags found for %s\n", con_id);
3109 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3110 status = gpiod_direction_output(desc,
3111 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
3113 status = gpiod_direction_input(desc);
3119 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3120 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3121 * @con_id: function within the GPIO consumer
3122 * @idx: index of the GPIO to obtain in the consumer
3123 * @flags: optional GPIO initialization flags
3125 * This variant of gpiod_get() allows to access GPIOs other than the first
3126 * defined one for functions that define several GPIOs.
3128 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3129 * requested function and/or index, or another IS_ERR() code if an error
3130 * occurred while trying to acquire the GPIO.
3132 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3135 enum gpiod_flags flags)
3137 struct gpio_desc *desc = NULL;
3139 enum gpio_lookup_flags lookupflags = 0;
3141 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3144 /* Using device tree? */
3145 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3146 dev_dbg(dev, "using device tree for GPIO lookup\n");
3147 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3148 } else if (ACPI_COMPANION(dev)) {
3149 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3150 desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
3155 * Either we are not using DT or ACPI, or their lookup did not return
3156 * a result. In that case, use platform lookup as a fallback.
3158 if (!desc || desc == ERR_PTR(-ENOENT)) {
3159 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3160 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3164 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
3168 status = gpiod_request(desc, con_id);
3170 return ERR_PTR(status);
3172 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3174 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3176 return ERR_PTR(status);
3181 EXPORT_SYMBOL_GPL(gpiod_get_index);
3184 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3185 * @fwnode: handle of the firmware node
3186 * @propname: name of the firmware property representing the GPIO
3188 * This function can be used for drivers that get their configuration
3191 * Function properly finds the corresponding GPIO using whatever is the
3192 * underlying firmware interface and then makes sure that the GPIO
3193 * descriptor is requested before it is returned to the caller.
3195 * In case of error an ERR_PTR() is returned.
3197 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3198 const char *propname)
3200 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3201 bool active_low = false;
3202 bool single_ended = false;
3206 return ERR_PTR(-EINVAL);
3208 if (is_of_node(fwnode)) {
3209 enum of_gpio_flags flags;
3211 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
3213 if (!IS_ERR(desc)) {
3214 active_low = flags & OF_GPIO_ACTIVE_LOW;
3215 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3217 } else if (is_acpi_node(fwnode)) {
3218 struct acpi_gpio_info info;
3220 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
3222 active_low = info.polarity == GPIO_ACTIVE_LOW;
3228 ret = gpiod_request(desc, NULL);
3230 return ERR_PTR(ret);
3233 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3237 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3239 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3244 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3247 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3249 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3250 * @con_id: function within the GPIO consumer
3251 * @index: index of the GPIO to obtain in the consumer
3252 * @flags: optional GPIO initialization flags
3254 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3255 * specified index was assigned to the requested function it will return NULL.
3256 * This is convenient for drivers that need to handle optional GPIOs.
3258 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3261 enum gpiod_flags flags)
3263 struct gpio_desc *desc;
3265 desc = gpiod_get_index(dev, con_id, index, flags);
3267 if (PTR_ERR(desc) == -ENOENT)
3273 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3276 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3277 * @desc: gpio whose value will be assigned
3278 * @name: gpio line name
3279 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3281 * @dflags: gpiod_flags - optional GPIO initialization flags
3283 int gpiod_hog(struct gpio_desc *desc, const char *name,
3284 unsigned long lflags, enum gpiod_flags dflags)
3286 struct gpio_chip *chip;
3287 struct gpio_desc *local_desc;
3291 chip = gpiod_to_chip(desc);
3292 hwnum = gpio_chip_hwgpio(desc);
3294 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3295 if (IS_ERR(local_desc)) {
3296 status = PTR_ERR(local_desc);
3297 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3298 name, chip->label, hwnum, status);
3302 status = gpiod_configure_flags(desc, name, lflags, dflags);
3304 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3305 name, chip->label, hwnum, status);
3306 gpiochip_free_own_desc(desc);
3310 /* Mark GPIO as hogged so it can be identified and removed later */
3311 set_bit(FLAG_IS_HOGGED, &desc->flags);
3313 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3314 desc_to_gpio(desc), name,
3315 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3316 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3317 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3323 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3324 * @chip: gpio chip to act on
3326 * This is only used by of_gpiochip_remove to free hogged gpios
3328 static void gpiochip_free_hogs(struct gpio_chip *chip)
3332 for (id = 0; id < chip->ngpio; id++) {
3333 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3334 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3339 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3340 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3341 * @con_id: function within the GPIO consumer
3342 * @flags: optional GPIO initialization flags
3344 * This function acquires all the GPIOs defined under a given function.
3346 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3347 * no GPIO has been assigned to the requested function, or another IS_ERR()
3348 * code if an error occurred while trying to acquire the GPIOs.
3350 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
3352 enum gpiod_flags flags)
3354 struct gpio_desc *desc;
3355 struct gpio_descs *descs;
3358 count = gpiod_count(dev, con_id);
3360 return ERR_PTR(count);
3362 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
3365 return ERR_PTR(-ENOMEM);
3367 for (descs->ndescs = 0; descs->ndescs < count; ) {
3368 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
3370 gpiod_put_array(descs);
3371 return ERR_CAST(desc);
3373 descs->desc[descs->ndescs] = desc;
3378 EXPORT_SYMBOL_GPL(gpiod_get_array);
3381 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3383 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3384 * @con_id: function within the GPIO consumer
3385 * @flags: optional GPIO initialization flags
3387 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3388 * assigned to the requested function it will return NULL.
3390 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
3392 enum gpiod_flags flags)
3394 struct gpio_descs *descs;
3396 descs = gpiod_get_array(dev, con_id, flags);
3397 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
3402 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
3405 * gpiod_put - dispose of a GPIO descriptor
3406 * @desc: GPIO descriptor to dispose of
3408 * No descriptor can be used after gpiod_put() has been called on it.
3410 void gpiod_put(struct gpio_desc *desc)
3414 EXPORT_SYMBOL_GPL(gpiod_put);
3417 * gpiod_put_array - dispose of multiple GPIO descriptors
3418 * @descs: struct gpio_descs containing an array of descriptors
3420 void gpiod_put_array(struct gpio_descs *descs)
3424 for (i = 0; i < descs->ndescs; i++)
3425 gpiod_put(descs->desc[i]);
3429 EXPORT_SYMBOL_GPL(gpiod_put_array);
3431 static int __init gpiolib_dev_init(void)
3435 /* Register GPIO sysfs bus */
3436 ret = bus_register(&gpio_bus_type);
3438 pr_err("gpiolib: could not register GPIO bus type\n");
3442 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
3444 pr_err("gpiolib: failed to allocate char dev region\n");
3445 bus_unregister(&gpio_bus_type);
3447 gpiolib_initialized = true;
3448 gpiochip_setup_devs();
3452 core_initcall(gpiolib_dev_init);
3454 #ifdef CONFIG_DEBUG_FS
3456 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
3459 struct gpio_chip *chip = gdev->chip;
3460 unsigned gpio = gdev->base;
3461 struct gpio_desc *gdesc = &gdev->descs[0];
3465 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
3466 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
3468 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
3474 gpiod_get_direction(gdesc);
3475 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
3476 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
3477 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3478 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
3479 is_out ? "out" : "in ",
3481 ? (chip->get(chip, i) ? "hi" : "lo")
3483 is_irq ? "IRQ" : " ");
3484 seq_printf(s, "\n");
3488 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
3490 unsigned long flags;
3491 struct gpio_device *gdev = NULL;
3492 loff_t index = *pos;
3496 spin_lock_irqsave(&gpio_lock, flags);
3497 list_for_each_entry(gdev, &gpio_devices, list)
3499 spin_unlock_irqrestore(&gpio_lock, flags);
3502 spin_unlock_irqrestore(&gpio_lock, flags);
3507 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3509 unsigned long flags;
3510 struct gpio_device *gdev = v;
3513 spin_lock_irqsave(&gpio_lock, flags);
3514 if (list_is_last(&gdev->list, &gpio_devices))
3517 ret = list_entry(gdev->list.next, struct gpio_device, list);
3518 spin_unlock_irqrestore(&gpio_lock, flags);
3526 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3530 static int gpiolib_seq_show(struct seq_file *s, void *v)
3532 struct gpio_device *gdev = v;
3533 struct gpio_chip *chip = gdev->chip;
3534 struct device *parent;
3537 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3538 dev_name(&gdev->dev));
3542 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3543 dev_name(&gdev->dev),
3544 gdev->base, gdev->base + gdev->ngpio - 1);
3545 parent = chip->parent;
3547 seq_printf(s, ", parent: %s/%s",
3548 parent->bus ? parent->bus->name : "no-bus",
3551 seq_printf(s, ", %s", chip->label);
3552 if (chip->can_sleep)
3553 seq_printf(s, ", can sleep");
3554 seq_printf(s, ":\n");
3557 chip->dbg_show(s, chip);
3559 gpiolib_dbg_show(s, gdev);
3564 static const struct seq_operations gpiolib_seq_ops = {
3565 .start = gpiolib_seq_start,
3566 .next = gpiolib_seq_next,
3567 .stop = gpiolib_seq_stop,
3568 .show = gpiolib_seq_show,
3571 static int gpiolib_open(struct inode *inode, struct file *file)
3573 return seq_open(file, &gpiolib_seq_ops);
3576 static const struct file_operations gpiolib_operations = {
3577 .owner = THIS_MODULE,
3578 .open = gpiolib_open,
3580 .llseek = seq_lseek,
3581 .release = seq_release,
3584 static int __init gpiolib_debugfs_init(void)
3586 /* /sys/kernel/debug/gpio */
3587 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3588 NULL, NULL, &gpiolib_operations);
3591 subsys_initcall(gpiolib_debugfs_init);
3593 #endif /* DEBUG_FS */