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/idr.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <uapi/linux/gpio.h>
28 #define CREATE_TRACE_POINTS
29 #include <trace/events/gpio.h>
31 /* Implementation infrastructure for GPIO interfaces.
33 * The GPIO programming interface allows for inlining speed-critical
34 * get/set operations for common cases, so that access to SOC-integrated
35 * GPIOs can sometimes cost only an instruction or two per bit.
39 /* When debugging, extend minimal trust to callers and platform code.
40 * Also emit diagnostic messages that may help initial bringup, when
41 * board setup or driver bugs are most common.
43 * Otherwise, minimize overhead in what may be bitbanging codepaths.
46 #define extra_checks 1
48 #define extra_checks 0
51 /* Device and char device-related information */
52 static DEFINE_IDA(gpio_ida
);
53 static dev_t gpio_devt
;
54 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
55 static struct bus_type gpio_bus_type
= {
59 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
60 * While any GPIO is requested, its gpio_chip is not removable;
61 * each GPIO's "requested" flag serves as a lock and refcount.
63 DEFINE_SPINLOCK(gpio_lock
);
65 static DEFINE_MUTEX(gpio_lookup_lock
);
66 static LIST_HEAD(gpio_lookup_list
);
67 LIST_HEAD(gpio_devices
);
69 static void gpiochip_free_hogs(struct gpio_chip
*chip
);
70 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
);
72 static bool gpiolib_initialized
;
74 static inline void desc_set_label(struct gpio_desc
*d
, const char *label
)
80 * Convert a GPIO number to its descriptor
82 struct gpio_desc
*gpio_to_desc(unsigned gpio
)
84 struct gpio_device
*gdev
;
87 spin_lock_irqsave(&gpio_lock
, flags
);
89 list_for_each_entry(gdev
, &gpio_devices
, list
) {
90 if (gdev
->base
<= gpio
&&
91 gdev
->base
+ gdev
->ngpio
> gpio
) {
92 spin_unlock_irqrestore(&gpio_lock
, flags
);
93 return &gdev
->descs
[gpio
- gdev
->base
];
97 spin_unlock_irqrestore(&gpio_lock
, flags
);
99 if (!gpio_is_valid(gpio
))
100 WARN(1, "invalid GPIO %d\n", gpio
);
104 EXPORT_SYMBOL_GPL(gpio_to_desc
);
107 * Get the GPIO descriptor corresponding to the given hw number for this chip.
109 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
112 struct gpio_device
*gdev
= chip
->gpiodev
;
114 if (hwnum
>= gdev
->ngpio
)
115 return ERR_PTR(-EINVAL
);
117 return &gdev
->descs
[hwnum
];
121 * Convert a GPIO descriptor to the integer namespace.
122 * This should disappear in the future but is needed since we still
123 * use GPIO numbers for error messages and sysfs nodes
125 int desc_to_gpio(const struct gpio_desc
*desc
)
127 return desc
->gdev
->base
+ (desc
- &desc
->gdev
->descs
[0]);
129 EXPORT_SYMBOL_GPL(desc_to_gpio
);
133 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
134 * @desc: descriptor to return the chip of
136 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
138 if (!desc
|| !desc
->gdev
|| !desc
->gdev
->chip
)
140 return desc
->gdev
->chip
;
142 EXPORT_SYMBOL_GPL(gpiod_to_chip
);
144 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
145 static int gpiochip_find_base(int ngpio
)
147 struct gpio_device
*gdev
;
148 int base
= ARCH_NR_GPIOS
- ngpio
;
150 list_for_each_entry_reverse(gdev
, &gpio_devices
, list
) {
151 /* found a free space? */
152 if (gdev
->base
+ gdev
->ngpio
<= base
)
155 /* nope, check the space right before the chip */
156 base
= gdev
->base
- ngpio
;
159 if (gpio_is_valid(base
)) {
160 pr_debug("%s: found new base at %d\n", __func__
, base
);
163 pr_err("%s: cannot find free range\n", __func__
);
169 * gpiod_get_direction - return the current direction of a GPIO
170 * @desc: GPIO to get the direction of
172 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
174 * This function may sleep if gpiod_cansleep() is true.
176 int gpiod_get_direction(struct gpio_desc
*desc
)
178 struct gpio_chip
*chip
;
180 int status
= -EINVAL
;
182 chip
= gpiod_to_chip(desc
);
183 offset
= gpio_chip_hwgpio(desc
);
185 if (!chip
->get_direction
)
188 status
= chip
->get_direction(chip
, offset
);
190 /* GPIOF_DIR_IN, or other positive */
192 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
196 set_bit(FLAG_IS_OUT
, &desc
->flags
);
200 EXPORT_SYMBOL_GPL(gpiod_get_direction
);
203 * Add a new chip to the global chips list, keeping the list of chips sorted
204 * by range(means [base, base + ngpio - 1]) order.
206 * Return -EBUSY if the new chip overlaps with some other chip's integer
209 static int gpiodev_add_to_list(struct gpio_device
*gdev
)
211 struct gpio_device
*prev
, *next
;
213 if (list_empty(&gpio_devices
)) {
214 /* initial entry in list */
215 list_add_tail(&gdev
->list
, &gpio_devices
);
219 next
= list_entry(gpio_devices
.next
, struct gpio_device
, list
);
220 if (gdev
->base
+ gdev
->ngpio
<= next
->base
) {
221 /* add before first entry */
222 list_add(&gdev
->list
, &gpio_devices
);
226 prev
= list_entry(gpio_devices
.prev
, struct gpio_device
, list
);
227 if (prev
->base
+ prev
->ngpio
<= gdev
->base
) {
228 /* add behind last entry */
229 list_add_tail(&gdev
->list
, &gpio_devices
);
233 list_for_each_entry_safe(prev
, next
, &gpio_devices
, list
) {
234 /* at the end of the list */
235 if (&next
->list
== &gpio_devices
)
238 /* add between prev and next */
239 if (prev
->base
+ prev
->ngpio
<= gdev
->base
240 && gdev
->base
+ gdev
->ngpio
<= next
->base
) {
241 list_add(&gdev
->list
, &prev
->list
);
246 dev_err(&gdev
->dev
, "GPIO integer space overlap, cannot add chip\n");
251 * Convert a GPIO name to its descriptor
253 static struct gpio_desc
*gpio_name_to_desc(const char * const name
)
255 struct gpio_device
*gdev
;
258 spin_lock_irqsave(&gpio_lock
, flags
);
260 list_for_each_entry(gdev
, &gpio_devices
, list
) {
263 for (i
= 0; i
!= gdev
->ngpio
; ++i
) {
264 struct gpio_desc
*desc
= &gdev
->descs
[i
];
266 if (!desc
->name
|| !name
)
269 if (!strcmp(desc
->name
, name
)) {
270 spin_unlock_irqrestore(&gpio_lock
, flags
);
276 spin_unlock_irqrestore(&gpio_lock
, flags
);
282 * Takes the names from gc->names and checks if they are all unique. If they
283 * are, they are assigned to their gpio descriptors.
285 * Warning if one of the names is already used for a different GPIO.
287 static int gpiochip_set_desc_names(struct gpio_chip
*gc
)
289 struct gpio_device
*gdev
= gc
->gpiodev
;
295 /* First check all names if they are unique */
296 for (i
= 0; i
!= gc
->ngpio
; ++i
) {
297 struct gpio_desc
*gpio
;
299 gpio
= gpio_name_to_desc(gc
->names
[i
]);
302 "Detected name collision for GPIO name '%s'\n",
306 /* Then add all names to the GPIO descriptors */
307 for (i
= 0; i
!= gc
->ngpio
; ++i
)
308 gdev
->descs
[i
].name
= gc
->names
[i
];
314 * gpio_ioctl() - ioctl handler for the GPIO chardev
316 static long gpio_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
318 struct gpio_device
*gdev
= filp
->private_data
;
319 struct gpio_chip
*chip
= gdev
->chip
;
320 void __user
*ip
= (void __user
*)arg
;
322 /* We fail any subsequent ioctl():s when the chip is gone */
326 /* Fill in the struct and pass to userspace */
327 if (cmd
== GPIO_GET_CHIPINFO_IOCTL
) {
328 struct gpiochip_info chipinfo
;
330 strncpy(chipinfo
.name
, dev_name(&gdev
->dev
),
331 sizeof(chipinfo
.name
));
332 chipinfo
.name
[sizeof(chipinfo
.name
)-1] = '\0';
333 strncpy(chipinfo
.label
, gdev
->label
,
334 sizeof(chipinfo
.label
));
335 chipinfo
.label
[sizeof(chipinfo
.label
)-1] = '\0';
336 chipinfo
.lines
= gdev
->ngpio
;
337 if (copy_to_user(ip
, &chipinfo
, sizeof(chipinfo
)))
340 } else if (cmd
== GPIO_GET_LINEINFO_IOCTL
) {
341 struct gpioline_info lineinfo
;
342 struct gpio_desc
*desc
;
344 if (copy_from_user(&lineinfo
, ip
, sizeof(lineinfo
)))
346 if (lineinfo
.line_offset
> gdev
->ngpio
)
349 desc
= &gdev
->descs
[lineinfo
.line_offset
];
351 strncpy(lineinfo
.name
, desc
->name
,
352 sizeof(lineinfo
.name
));
353 lineinfo
.name
[sizeof(lineinfo
.name
)-1] = '\0';
355 lineinfo
.name
[0] = '\0';
358 strncpy(lineinfo
.consumer
, desc
->label
,
359 sizeof(lineinfo
.consumer
));
360 lineinfo
.consumer
[sizeof(lineinfo
.consumer
)-1] = '\0';
362 lineinfo
.consumer
[0] = '\0';
366 * Userspace only need to know that the kernel is using
367 * this GPIO so it can't use it.
370 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) ||
371 test_bit(FLAG_IS_HOGGED
, &desc
->flags
) ||
372 test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
) ||
373 test_bit(FLAG_EXPORT
, &desc
->flags
) ||
374 test_bit(FLAG_SYSFS
, &desc
->flags
))
375 lineinfo
.flags
|= GPIOLINE_FLAG_KERNEL
;
376 if (test_bit(FLAG_IS_OUT
, &desc
->flags
))
377 lineinfo
.flags
|= GPIOLINE_FLAG_IS_OUT
;
378 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
379 lineinfo
.flags
|= GPIOLINE_FLAG_ACTIVE_LOW
;
380 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
381 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_DRAIN
;
382 if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
383 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_SOURCE
;
385 if (copy_to_user(ip
, &lineinfo
, sizeof(lineinfo
)))
393 static long gpio_ioctl_compat(struct file
*filp
, unsigned int cmd
,
396 return gpio_ioctl(filp
, cmd
, (unsigned long)compat_ptr(arg
));
401 * gpio_chrdev_open() - open the chardev for ioctl operations
402 * @inode: inode for this chardev
403 * @filp: file struct for storing private data
404 * Returns 0 on success
406 static int gpio_chrdev_open(struct inode
*inode
, struct file
*filp
)
408 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
409 struct gpio_device
, chrdev
);
411 /* Fail on open if the backing gpiochip is gone */
412 if (!gdev
|| !gdev
->chip
)
414 get_device(&gdev
->dev
);
415 filp
->private_data
= gdev
;
420 * gpio_chrdev_release() - close chardev after ioctl operations
421 * @inode: inode for this chardev
422 * @filp: file struct for storing private data
423 * Returns 0 on success
425 static int gpio_chrdev_release(struct inode
*inode
, struct file
*filp
)
427 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
428 struct gpio_device
, chrdev
);
432 put_device(&gdev
->dev
);
437 static const struct file_operations gpio_fileops
= {
438 .release
= gpio_chrdev_release
,
439 .open
= gpio_chrdev_open
,
440 .owner
= THIS_MODULE
,
441 .llseek
= noop_llseek
,
442 .unlocked_ioctl
= gpio_ioctl
,
444 .compat_ioctl
= gpio_ioctl_compat
,
448 static void gpiodevice_release(struct device
*dev
)
450 struct gpio_device
*gdev
= dev_get_drvdata(dev
);
452 cdev_del(&gdev
->chrdev
);
453 list_del(&gdev
->list
);
454 ida_simple_remove(&gpio_ida
, gdev
->id
);
460 static int gpiochip_setup_dev(struct gpio_device
*gdev
)
464 cdev_init(&gdev
->chrdev
, &gpio_fileops
);
465 gdev
->chrdev
.owner
= THIS_MODULE
;
466 gdev
->chrdev
.kobj
.parent
= &gdev
->dev
.kobj
;
467 gdev
->dev
.devt
= MKDEV(MAJOR(gpio_devt
), gdev
->id
);
468 status
= cdev_add(&gdev
->chrdev
, gdev
->dev
.devt
, 1);
470 chip_warn(gdev
->chip
, "failed to add char device %d:%d\n",
471 MAJOR(gpio_devt
), gdev
->id
);
473 chip_dbg(gdev
->chip
, "added GPIO chardev (%d:%d)\n",
474 MAJOR(gpio_devt
), gdev
->id
);
475 status
= device_add(&gdev
->dev
);
477 goto err_remove_chardev
;
479 status
= gpiochip_sysfs_register(gdev
);
481 goto err_remove_device
;
483 /* From this point, the .release() function cleans up gpio_device */
484 gdev
->dev
.release
= gpiodevice_release
;
485 get_device(&gdev
->dev
);
486 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
487 __func__
, gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
488 dev_name(&gdev
->dev
), gdev
->chip
->label
? : "generic");
493 device_del(&gdev
->dev
);
495 cdev_del(&gdev
->chrdev
);
499 static void gpiochip_setup_devs(void)
501 struct gpio_device
*gdev
;
504 list_for_each_entry(gdev
, &gpio_devices
, list
) {
505 err
= gpiochip_setup_dev(gdev
);
507 pr_err("%s: Failed to initialize gpio device (%d)\n",
508 dev_name(&gdev
->dev
), err
);
513 * gpiochip_add_data() - register a gpio_chip
514 * @chip: the chip to register, with chip->base initialized
515 * Context: potentially before irqs will work
517 * Returns a negative errno if the chip can't be registered, such as
518 * because the chip->base is invalid or already associated with a
519 * different chip. Otherwise it returns zero as a success code.
521 * When gpiochip_add_data() is called very early during boot, so that GPIOs
522 * can be freely used, the chip->parent device must be registered before
523 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
524 * for GPIOs will fail rudely.
526 * gpiochip_add_data() must only be called after gpiolib initialization,
527 * ie after core_initcall().
529 * If chip->base is negative, this requests dynamic assignment of
530 * a range of valid GPIOs.
532 int gpiochip_add_data(struct gpio_chip
*chip
, void *data
)
537 int base
= chip
->base
;
538 struct gpio_device
*gdev
;
541 * First: allocate and populate the internal stat container, and
542 * set up the struct device.
544 gdev
= kzalloc(sizeof(*gdev
), GFP_KERNEL
);
547 gdev
->dev
.bus
= &gpio_bus_type
;
549 chip
->gpiodev
= gdev
;
551 gdev
->dev
.parent
= chip
->parent
;
552 gdev
->dev
.of_node
= chip
->parent
->of_node
;
554 #ifdef CONFIG_OF_GPIO
555 /* If the gpiochip has an assigned OF node this takes precedence */
557 gdev
->dev
.of_node
= chip
->of_node
;
560 gdev
->id
= ida_simple_get(&gpio_ida
, 0, 0, GFP_KERNEL
);
565 dev_set_name(&gdev
->dev
, "gpiochip%d", gdev
->id
);
566 device_initialize(&gdev
->dev
);
567 dev_set_drvdata(&gdev
->dev
, gdev
);
568 if (chip
->parent
&& chip
->parent
->driver
)
569 gdev
->owner
= chip
->parent
->driver
->owner
;
570 else if (chip
->owner
)
571 /* TODO: remove chip->owner */
572 gdev
->owner
= chip
->owner
;
574 gdev
->owner
= THIS_MODULE
;
576 gdev
->descs
= kcalloc(chip
->ngpio
, sizeof(gdev
->descs
[0]), GFP_KERNEL
);
582 if (chip
->ngpio
== 0) {
583 chip_err(chip
, "tried to insert a GPIO chip with zero lines\n");
589 gdev
->label
= kstrdup(chip
->label
, GFP_KERNEL
);
591 gdev
->label
= kstrdup("unknown", GFP_KERNEL
);
597 gdev
->ngpio
= chip
->ngpio
;
600 spin_lock_irqsave(&gpio_lock
, flags
);
603 * TODO: this allocates a Linux GPIO number base in the global
604 * GPIO numberspace for this chip. In the long run we want to
605 * get *rid* of this numberspace and use only descriptors, but
606 * it may be a pipe dream. It will not happen before we get rid
607 * of the sysfs interface anyways.
610 base
= gpiochip_find_base(chip
->ngpio
);
613 spin_unlock_irqrestore(&gpio_lock
, flags
);
617 * TODO: it should not be necessary to reflect the assigned
618 * base outside of the GPIO subsystem. Go over drivers and
619 * see if anyone makes use of this, else drop this and assign
626 status
= gpiodev_add_to_list(gdev
);
628 spin_unlock_irqrestore(&gpio_lock
, flags
);
632 spin_unlock_irqrestore(&gpio_lock
, flags
);
634 for (i
= 0; i
< chip
->ngpio
; i
++) {
635 struct gpio_desc
*desc
= &gdev
->descs
[i
];
639 * REVISIT: most hardware initializes GPIOs as inputs
640 * (often with pullups enabled) so power usage is
641 * minimized. Linux code should set the gpio direction
642 * first thing; but until it does, and in case
643 * chip->get_direction is not set, we may expose the
644 * wrong direction in sysfs.
647 if (chip
->get_direction
) {
649 * If we have .get_direction, set up the initial
650 * direction flag from the hardware.
652 int dir
= chip
->get_direction(chip
, i
);
655 set_bit(FLAG_IS_OUT
, &desc
->flags
);
656 } else if (!chip
->direction_input
) {
658 * If the chip lacks the .direction_input callback
659 * we logically assume all lines are outputs.
661 set_bit(FLAG_IS_OUT
, &desc
->flags
);
665 #ifdef CONFIG_PINCTRL
666 INIT_LIST_HEAD(&gdev
->pin_ranges
);
669 status
= gpiochip_set_desc_names(chip
);
671 goto err_remove_from_list
;
673 status
= of_gpiochip_add(chip
);
675 goto err_remove_chip
;
677 acpi_gpiochip_add(chip
);
680 * By first adding the chardev, and then adding the device,
681 * we get a device node entry in sysfs under
682 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
683 * coldplug of device nodes and other udev business.
684 * We can do this only if gpiolib has been initialized.
685 * Otherwise, defer until later.
687 if (gpiolib_initialized
) {
688 status
= gpiochip_setup_dev(gdev
);
690 goto err_remove_chip
;
695 acpi_gpiochip_remove(chip
);
696 gpiochip_free_hogs(chip
);
697 of_gpiochip_remove(chip
);
698 err_remove_from_list
:
699 spin_lock_irqsave(&gpio_lock
, flags
);
700 list_del(&gdev
->list
);
701 spin_unlock_irqrestore(&gpio_lock
, flags
);
707 ida_simple_remove(&gpio_ida
, gdev
->id
);
708 /* failures here can mean systems won't boot... */
709 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__
,
710 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
711 chip
->label
? : "generic");
715 EXPORT_SYMBOL_GPL(gpiochip_add_data
);
718 * gpiochip_get_data() - get per-subdriver data for the chip
720 void *gpiochip_get_data(struct gpio_chip
*chip
)
722 return chip
->gpiodev
->data
;
724 EXPORT_SYMBOL_GPL(gpiochip_get_data
);
727 * gpiochip_remove() - unregister a gpio_chip
728 * @chip: the chip to unregister
730 * A gpio_chip with any GPIOs still requested may not be removed.
732 void gpiochip_remove(struct gpio_chip
*chip
)
734 struct gpio_device
*gdev
= chip
->gpiodev
;
735 struct gpio_desc
*desc
;
738 bool requested
= false;
740 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
741 gpiochip_sysfs_unregister(gdev
);
742 /* Numb the device, cancelling all outstanding operations */
744 gpiochip_irqchip_remove(chip
);
745 acpi_gpiochip_remove(chip
);
746 gpiochip_remove_pin_ranges(chip
);
747 gpiochip_free_hogs(chip
);
748 of_gpiochip_remove(chip
);
750 * We accept no more calls into the driver from this point, so
751 * NULL the driver data pointer
755 spin_lock_irqsave(&gpio_lock
, flags
);
756 for (i
= 0; i
< gdev
->ngpio
; i
++) {
757 desc
= &gdev
->descs
[i
];
758 if (test_bit(FLAG_REQUESTED
, &desc
->flags
))
761 spin_unlock_irqrestore(&gpio_lock
, flags
);
765 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
768 * The gpiochip side puts its use of the device to rest here:
769 * if there are no userspace clients, the chardev and device will
770 * be removed, else it will be dangling until the last user is
773 put_device(&gdev
->dev
);
775 EXPORT_SYMBOL_GPL(gpiochip_remove
);
777 static void devm_gpio_chip_release(struct device
*dev
, void *res
)
779 struct gpio_chip
*chip
= *(struct gpio_chip
**)res
;
781 gpiochip_remove(chip
);
784 static int devm_gpio_chip_match(struct device
*dev
, void *res
, void *data
)
787 struct gpio_chip
**r
= res
;
798 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
799 * @dev: the device pointer on which irq_chip belongs to.
800 * @chip: the chip to register, with chip->base initialized
801 * Context: potentially before irqs will work
803 * Returns a negative errno if the chip can't be registered, such as
804 * because the chip->base is invalid or already associated with a
805 * different chip. Otherwise it returns zero as a success code.
807 * The gpio chip automatically be released when the device is unbound.
809 int devm_gpiochip_add_data(struct device
*dev
, struct gpio_chip
*chip
,
812 struct gpio_chip
**ptr
;
815 ptr
= devres_alloc(devm_gpio_chip_release
, sizeof(*ptr
),
820 ret
= gpiochip_add_data(chip
, data
);
827 devres_add(dev
, ptr
);
831 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data
);
834 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
835 * @dev: device for which which resource was allocated
836 * @chip: the chip to remove
838 * A gpio_chip with any GPIOs still requested may not be removed.
840 void devm_gpiochip_remove(struct device
*dev
, struct gpio_chip
*chip
)
844 ret
= devres_release(dev
, devm_gpio_chip_release
,
845 devm_gpio_chip_match
, chip
);
849 EXPORT_SYMBOL_GPL(devm_gpiochip_remove
);
852 * gpiochip_find() - iterator for locating a specific gpio_chip
853 * @data: data to pass to match function
854 * @callback: Callback function to check gpio_chip
856 * Similar to bus_find_device. It returns a reference to a gpio_chip as
857 * determined by a user supplied @match callback. The callback should return
858 * 0 if the device doesn't match and non-zero if it does. If the callback is
859 * non-zero, this function will return to the caller and not iterate over any
862 struct gpio_chip
*gpiochip_find(void *data
,
863 int (*match
)(struct gpio_chip
*chip
,
866 struct gpio_device
*gdev
;
867 struct gpio_chip
*chip
;
870 spin_lock_irqsave(&gpio_lock
, flags
);
871 list_for_each_entry(gdev
, &gpio_devices
, list
)
872 if (match(gdev
->chip
, data
))
876 if (&gdev
->list
== &gpio_devices
)
881 spin_unlock_irqrestore(&gpio_lock
, flags
);
885 EXPORT_SYMBOL_GPL(gpiochip_find
);
887 static int gpiochip_match_name(struct gpio_chip
*chip
, void *data
)
889 const char *name
= data
;
891 return !strcmp(chip
->label
, name
);
894 static struct gpio_chip
*find_chip_by_name(const char *name
)
896 return gpiochip_find((void *)name
, gpiochip_match_name
);
899 #ifdef CONFIG_GPIOLIB_IRQCHIP
902 * The following is irqchip helper code for gpiochips.
906 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
907 * @gpiochip: the gpiochip to set the irqchip chain to
908 * @irqchip: the irqchip to chain to the gpiochip
909 * @parent_irq: the irq number corresponding to the parent IRQ for this
911 * @parent_handler: the parent interrupt handler for the accumulated IRQ
912 * coming out of the gpiochip. If the interrupt is nested rather than
913 * cascaded, pass NULL in this handler argument
915 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
916 struct irq_chip
*irqchip
,
918 irq_flow_handler_t parent_handler
)
922 if (!gpiochip
->irqdomain
) {
923 chip_err(gpiochip
, "called %s before setting up irqchip\n",
928 if (parent_handler
) {
929 if (gpiochip
->can_sleep
) {
931 "you cannot have chained interrupts on a "
932 "chip that may sleep\n");
936 * The parent irqchip is already using the chip_data for this
937 * irqchip, so our callbacks simply use the handler_data.
939 irq_set_chained_handler_and_data(parent_irq
, parent_handler
,
942 gpiochip
->irq_parent
= parent_irq
;
945 /* Set the parent IRQ for all affected IRQs */
946 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
947 irq_set_parent(irq_find_mapping(gpiochip
->irqdomain
, offset
),
950 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip
);
953 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
954 * @d: the irqdomain used by this irqchip
955 * @irq: the global irq number used by this GPIO irqchip irq
956 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
958 * This function will set up the mapping for a certain IRQ line on a
959 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
960 * stored inside the gpiochip.
962 static int gpiochip_irq_map(struct irq_domain
*d
, unsigned int irq
,
963 irq_hw_number_t hwirq
)
965 struct gpio_chip
*chip
= d
->host_data
;
967 irq_set_chip_data(irq
, chip
);
969 * This lock class tells lockdep that GPIO irqs are in a different
970 * category than their parents, so it won't report false recursion.
972 irq_set_lockdep_class(irq
, chip
->lock_key
);
973 irq_set_chip_and_handler(irq
, chip
->irqchip
, chip
->irq_handler
);
974 /* Chips that can sleep need nested thread handlers */
975 if (chip
->can_sleep
&& !chip
->irq_not_threaded
)
976 irq_set_nested_thread(irq
, 1);
977 irq_set_noprobe(irq
);
980 * No set-up of the hardware will happen if IRQ_TYPE_NONE
981 * is passed as default type.
983 if (chip
->irq_default_type
!= IRQ_TYPE_NONE
)
984 irq_set_irq_type(irq
, chip
->irq_default_type
);
989 static void gpiochip_irq_unmap(struct irq_domain
*d
, unsigned int irq
)
991 struct gpio_chip
*chip
= d
->host_data
;
994 irq_set_nested_thread(irq
, 0);
995 irq_set_chip_and_handler(irq
, NULL
, NULL
);
996 irq_set_chip_data(irq
, NULL
);
999 static const struct irq_domain_ops gpiochip_domain_ops
= {
1000 .map
= gpiochip_irq_map
,
1001 .unmap
= gpiochip_irq_unmap
,
1002 /* Virtually all GPIO irqchips are twocell:ed */
1003 .xlate
= irq_domain_xlate_twocell
,
1006 static int gpiochip_irq_reqres(struct irq_data
*d
)
1008 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1010 if (!try_module_get(chip
->gpiodev
->owner
))
1013 if (gpiochip_lock_as_irq(chip
, d
->hwirq
)) {
1015 "unable to lock HW IRQ %lu for IRQ\n",
1017 module_put(chip
->gpiodev
->owner
);
1023 static void gpiochip_irq_relres(struct irq_data
*d
)
1025 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1027 gpiochip_unlock_as_irq(chip
, d
->hwirq
);
1028 module_put(chip
->gpiodev
->owner
);
1031 static int gpiochip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
1033 return irq_find_mapping(chip
->irqdomain
, offset
);
1037 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1038 * @gpiochip: the gpiochip to remove the irqchip from
1040 * This is called only from gpiochip_remove()
1042 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
)
1044 unsigned int offset
;
1046 acpi_gpiochip_free_interrupts(gpiochip
);
1048 if (gpiochip
->irq_parent
) {
1049 irq_set_chained_handler(gpiochip
->irq_parent
, NULL
);
1050 irq_set_handler_data(gpiochip
->irq_parent
, NULL
);
1053 /* Remove all IRQ mappings and delete the domain */
1054 if (gpiochip
->irqdomain
) {
1055 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
1056 irq_dispose_mapping(
1057 irq_find_mapping(gpiochip
->irqdomain
, offset
));
1058 irq_domain_remove(gpiochip
->irqdomain
);
1061 if (gpiochip
->irqchip
) {
1062 gpiochip
->irqchip
->irq_request_resources
= NULL
;
1063 gpiochip
->irqchip
->irq_release_resources
= NULL
;
1064 gpiochip
->irqchip
= NULL
;
1069 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1070 * @gpiochip: the gpiochip to add the irqchip to
1071 * @irqchip: the irqchip to add to the gpiochip
1072 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1073 * allocate gpiochip irqs from
1074 * @handler: the irq handler to use (often a predefined irq core function)
1075 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1076 * to have the core avoid setting up any default type in the hardware.
1077 * @lock_key: lockdep class
1079 * This function closely associates a certain irqchip with a certain
1080 * gpiochip, providing an irq domain to translate the local IRQs to
1081 * global irqs in the gpiolib core, and making sure that the gpiochip
1082 * is passed as chip data to all related functions. Driver callbacks
1083 * need to use gpiochip_get_data() to get their local state containers back
1084 * from the gpiochip passed as chip data. An irqdomain will be stored
1085 * in the gpiochip that shall be used by the driver to handle IRQ number
1086 * translation. The gpiochip will need to be initialized and registered
1087 * before calling this function.
1089 * This function will handle two cell:ed simple IRQs and assumes all
1090 * the pins on the gpiochip can generate a unique IRQ. Everything else
1091 * need to be open coded.
1093 int _gpiochip_irqchip_add(struct gpio_chip
*gpiochip
,
1094 struct irq_chip
*irqchip
,
1095 unsigned int first_irq
,
1096 irq_flow_handler_t handler
,
1098 struct lock_class_key
*lock_key
)
1100 struct device_node
*of_node
;
1101 unsigned int offset
;
1102 unsigned irq_base
= 0;
1104 if (!gpiochip
|| !irqchip
)
1107 if (!gpiochip
->parent
) {
1108 pr_err("missing gpiochip .dev parent pointer\n");
1111 of_node
= gpiochip
->parent
->of_node
;
1112 #ifdef CONFIG_OF_GPIO
1114 * If the gpiochip has an assigned OF node this takes precedence
1115 * FIXME: get rid of this and use gpiochip->parent->of_node
1118 if (gpiochip
->of_node
)
1119 of_node
= gpiochip
->of_node
;
1121 gpiochip
->irqchip
= irqchip
;
1122 gpiochip
->irq_handler
= handler
;
1123 gpiochip
->irq_default_type
= type
;
1124 gpiochip
->to_irq
= gpiochip_to_irq
;
1125 gpiochip
->lock_key
= lock_key
;
1126 gpiochip
->irqdomain
= irq_domain_add_simple(of_node
,
1127 gpiochip
->ngpio
, first_irq
,
1128 &gpiochip_domain_ops
, gpiochip
);
1129 if (!gpiochip
->irqdomain
) {
1130 gpiochip
->irqchip
= NULL
;
1135 * It is possible for a driver to override this, but only if the
1136 * alternative functions are both implemented.
1138 if (!irqchip
->irq_request_resources
&&
1139 !irqchip
->irq_release_resources
) {
1140 irqchip
->irq_request_resources
= gpiochip_irq_reqres
;
1141 irqchip
->irq_release_resources
= gpiochip_irq_relres
;
1145 * Prepare the mapping since the irqchip shall be orthogonal to
1146 * any gpiochip calls. If the first_irq was zero, this is
1147 * necessary to allocate descriptors for all IRQs.
1149 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1150 irq_base
= irq_create_mapping(gpiochip
->irqdomain
, offset
);
1153 * Store the base into the gpiochip to be used when
1154 * unmapping the irqs.
1156 gpiochip
->irq_base
= irq_base
;
1159 acpi_gpiochip_request_interrupts(gpiochip
);
1163 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add
);
1165 #else /* CONFIG_GPIOLIB_IRQCHIP */
1167 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
) {}
1169 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1172 * gpiochip_generic_request() - request the gpio function for a pin
1173 * @chip: the gpiochip owning the GPIO
1174 * @offset: the offset of the GPIO to request for GPIO function
1176 int gpiochip_generic_request(struct gpio_chip
*chip
, unsigned offset
)
1178 return pinctrl_request_gpio(chip
->gpiodev
->base
+ offset
);
1180 EXPORT_SYMBOL_GPL(gpiochip_generic_request
);
1183 * gpiochip_generic_free() - free the gpio function from a pin
1184 * @chip: the gpiochip to request the gpio function for
1185 * @offset: the offset of the GPIO to free from GPIO function
1187 void gpiochip_generic_free(struct gpio_chip
*chip
, unsigned offset
)
1189 pinctrl_free_gpio(chip
->gpiodev
->base
+ offset
);
1191 EXPORT_SYMBOL_GPL(gpiochip_generic_free
);
1193 #ifdef CONFIG_PINCTRL
1196 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1197 * @chip: the gpiochip to add the range for
1198 * @pctldev: the pin controller to map to
1199 * @gpio_offset: the start offset in the current gpio_chip number space
1200 * @pin_group: name of the pin group inside the pin controller
1202 int gpiochip_add_pingroup_range(struct gpio_chip
*chip
,
1203 struct pinctrl_dev
*pctldev
,
1204 unsigned int gpio_offset
, const char *pin_group
)
1206 struct gpio_pin_range
*pin_range
;
1207 struct gpio_device
*gdev
= chip
->gpiodev
;
1210 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1212 chip_err(chip
, "failed to allocate pin ranges\n");
1216 /* Use local offset as range ID */
1217 pin_range
->range
.id
= gpio_offset
;
1218 pin_range
->range
.gc
= chip
;
1219 pin_range
->range
.name
= chip
->label
;
1220 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1221 pin_range
->pctldev
= pctldev
;
1223 ret
= pinctrl_get_group_pins(pctldev
, pin_group
,
1224 &pin_range
->range
.pins
,
1225 &pin_range
->range
.npins
);
1231 pinctrl_add_gpio_range(pctldev
, &pin_range
->range
);
1233 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1234 gpio_offset
, gpio_offset
+ pin_range
->range
.npins
- 1,
1235 pinctrl_dev_get_devname(pctldev
), pin_group
);
1237 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1241 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range
);
1244 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1245 * @chip: the gpiochip to add the range for
1246 * @pinctrl_name: the dev_name() of the pin controller to map to
1247 * @gpio_offset: the start offset in the current gpio_chip number space
1248 * @pin_offset: the start offset in the pin controller number space
1249 * @npins: the number of pins from the offset of each pin space (GPIO and
1250 * pin controller) to accumulate in this range
1252 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
1253 unsigned int gpio_offset
, unsigned int pin_offset
,
1256 struct gpio_pin_range
*pin_range
;
1257 struct gpio_device
*gdev
= chip
->gpiodev
;
1260 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1262 chip_err(chip
, "failed to allocate pin ranges\n");
1266 /* Use local offset as range ID */
1267 pin_range
->range
.id
= gpio_offset
;
1268 pin_range
->range
.gc
= chip
;
1269 pin_range
->range
.name
= chip
->label
;
1270 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1271 pin_range
->range
.pin_base
= pin_offset
;
1272 pin_range
->range
.npins
= npins
;
1273 pin_range
->pctldev
= pinctrl_find_and_add_gpio_range(pinctl_name
,
1275 if (IS_ERR(pin_range
->pctldev
)) {
1276 ret
= PTR_ERR(pin_range
->pctldev
);
1277 chip_err(chip
, "could not create pin range\n");
1281 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1282 gpio_offset
, gpio_offset
+ npins
- 1,
1284 pin_offset
, pin_offset
+ npins
- 1);
1286 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1290 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range
);
1293 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1294 * @chip: the chip to remove all the mappings for
1296 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
1298 struct gpio_pin_range
*pin_range
, *tmp
;
1299 struct gpio_device
*gdev
= chip
->gpiodev
;
1301 list_for_each_entry_safe(pin_range
, tmp
, &gdev
->pin_ranges
, node
) {
1302 list_del(&pin_range
->node
);
1303 pinctrl_remove_gpio_range(pin_range
->pctldev
,
1308 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges
);
1310 #endif /* CONFIG_PINCTRL */
1312 /* These "optional" allocation calls help prevent drivers from stomping
1313 * on each other, and help provide better diagnostics in debugfs.
1314 * They're called even less than the "set direction" calls.
1316 static int __gpiod_request(struct gpio_desc
*desc
, const char *label
)
1318 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1320 unsigned long flags
;
1322 spin_lock_irqsave(&gpio_lock
, flags
);
1324 /* NOTE: gpio_request() can be called in early boot,
1325 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1328 if (test_and_set_bit(FLAG_REQUESTED
, &desc
->flags
) == 0) {
1329 desc_set_label(desc
, label
? : "?");
1336 if (chip
->request
) {
1337 /* chip->request may sleep */
1338 spin_unlock_irqrestore(&gpio_lock
, flags
);
1339 status
= chip
->request(chip
, gpio_chip_hwgpio(desc
));
1340 spin_lock_irqsave(&gpio_lock
, flags
);
1343 desc_set_label(desc
, NULL
);
1344 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1348 if (chip
->get_direction
) {
1349 /* chip->get_direction may sleep */
1350 spin_unlock_irqrestore(&gpio_lock
, flags
);
1351 gpiod_get_direction(desc
);
1352 spin_lock_irqsave(&gpio_lock
, flags
);
1356 /* Clear flags that might have been set by the caller before
1357 * requesting the GPIO.
1359 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1360 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1361 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1363 spin_unlock_irqrestore(&gpio_lock
, flags
);
1368 * This descriptor validation needs to be inserted verbatim into each
1369 * function taking a descriptor, so we need to use a preprocessor
1370 * macro to avoid endless duplication. If the desc is NULL it is an
1371 * optional GPIO and calls should just bail out.
1373 #define VALIDATE_DESC(desc) do { \
1376 if (!desc->gdev) { \
1377 pr_warn("%s: invalid GPIO\n", __func__); \
1380 if ( !desc->gdev->chip ) { \
1381 dev_warn(&desc->gdev->dev, \
1382 "%s: backing chip is gone\n", __func__); \
1386 #define VALIDATE_DESC_VOID(desc) do { \
1389 if (!desc->gdev) { \
1390 pr_warn("%s: invalid GPIO\n", __func__); \
1393 if (!desc->gdev->chip) { \
1394 dev_warn(&desc->gdev->dev, \
1395 "%s: backing chip is gone\n", __func__); \
1400 int gpiod_request(struct gpio_desc
*desc
, const char *label
)
1402 int status
= -EPROBE_DEFER
;
1403 struct gpio_device
*gdev
;
1405 VALIDATE_DESC(desc
);
1408 if (try_module_get(gdev
->owner
)) {
1409 status
= __gpiod_request(desc
, label
);
1411 module_put(gdev
->owner
);
1413 get_device(&gdev
->dev
);
1417 gpiod_dbg(desc
, "%s: status %d\n", __func__
, status
);
1422 static bool __gpiod_free(struct gpio_desc
*desc
)
1425 unsigned long flags
;
1426 struct gpio_chip
*chip
;
1430 gpiod_unexport(desc
);
1432 spin_lock_irqsave(&gpio_lock
, flags
);
1434 chip
= desc
->gdev
->chip
;
1435 if (chip
&& test_bit(FLAG_REQUESTED
, &desc
->flags
)) {
1437 spin_unlock_irqrestore(&gpio_lock
, flags
);
1438 might_sleep_if(chip
->can_sleep
);
1439 chip
->free(chip
, gpio_chip_hwgpio(desc
));
1440 spin_lock_irqsave(&gpio_lock
, flags
);
1442 desc_set_label(desc
, NULL
);
1443 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1444 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1445 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1446 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1447 clear_bit(FLAG_IS_HOGGED
, &desc
->flags
);
1451 spin_unlock_irqrestore(&gpio_lock
, flags
);
1455 void gpiod_free(struct gpio_desc
*desc
)
1457 if (desc
&& desc
->gdev
&& __gpiod_free(desc
)) {
1458 module_put(desc
->gdev
->owner
);
1459 put_device(&desc
->gdev
->dev
);
1461 WARN_ON(extra_checks
);
1466 * gpiochip_is_requested - return string iff signal was requested
1467 * @chip: controller managing the signal
1468 * @offset: of signal within controller's 0..(ngpio - 1) range
1470 * Returns NULL if the GPIO is not currently requested, else a string.
1471 * The string returned is the label passed to gpio_request(); if none has been
1472 * passed it is a meaningless, non-NULL constant.
1474 * This function is for use by GPIO controller drivers. The label can
1475 * help with diagnostics, and knowing that the signal is used as a GPIO
1476 * can help avoid accidentally multiplexing it to another controller.
1478 const char *gpiochip_is_requested(struct gpio_chip
*chip
, unsigned offset
)
1480 struct gpio_desc
*desc
;
1482 if (offset
>= chip
->ngpio
)
1485 desc
= &chip
->gpiodev
->descs
[offset
];
1487 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) == 0)
1491 EXPORT_SYMBOL_GPL(gpiochip_is_requested
);
1494 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1495 * @desc: GPIO descriptor to request
1496 * @label: label for the GPIO
1498 * Function allows GPIO chip drivers to request and use their own GPIO
1499 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1500 * function will not increase reference count of the GPIO chip module. This
1501 * allows the GPIO chip module to be unloaded as needed (we assume that the
1502 * GPIO chip driver handles freeing the GPIOs it has requested).
1504 struct gpio_desc
*gpiochip_request_own_desc(struct gpio_chip
*chip
, u16 hwnum
,
1507 struct gpio_desc
*desc
= gpiochip_get_desc(chip
, hwnum
);
1511 chip_err(chip
, "failed to get GPIO descriptor\n");
1515 err
= __gpiod_request(desc
, label
);
1517 return ERR_PTR(err
);
1521 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc
);
1524 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1525 * @desc: GPIO descriptor to free
1527 * Function frees the given GPIO requested previously with
1528 * gpiochip_request_own_desc().
1530 void gpiochip_free_own_desc(struct gpio_desc
*desc
)
1535 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc
);
1538 * Drivers MUST set GPIO direction before making get/set calls. In
1539 * some cases this is done in early boot, before IRQs are enabled.
1541 * As a rule these aren't called more than once (except for drivers
1542 * using the open-drain emulation idiom) so these are natural places
1543 * to accumulate extra debugging checks. Note that we can't (yet)
1544 * rely on gpio_request() having been called beforehand.
1548 * gpiod_direction_input - set the GPIO direction to input
1549 * @desc: GPIO to set to input
1551 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1552 * be called safely on it.
1554 * Return 0 in case of success, else an error code.
1556 int gpiod_direction_input(struct gpio_desc
*desc
)
1558 struct gpio_chip
*chip
;
1559 int status
= -EINVAL
;
1561 VALIDATE_DESC(desc
);
1562 chip
= desc
->gdev
->chip
;
1564 if (!chip
->get
|| !chip
->direction_input
) {
1566 "%s: missing get() or direction_input() operations\n",
1571 status
= chip
->direction_input(chip
, gpio_chip_hwgpio(desc
));
1573 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1575 trace_gpio_direction(desc_to_gpio(desc
), 1, status
);
1579 EXPORT_SYMBOL_GPL(gpiod_direction_input
);
1581 static int _gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1583 struct gpio_chip
*gc
= desc
->gdev
->chip
;
1586 /* GPIOs used for IRQs shall not be set as output */
1587 if (test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
)) {
1589 "%s: tried to set a GPIO tied to an IRQ as output\n",
1594 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
1595 /* First see if we can enable open drain in hardware */
1596 if (gc
->set_single_ended
) {
1597 ret
= gc
->set_single_ended(gc
, gpio_chip_hwgpio(desc
),
1598 LINE_MODE_OPEN_DRAIN
);
1600 goto set_output_value
;
1602 /* Emulate open drain by not actively driving the line high */
1604 return gpiod_direction_input(desc
);
1606 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
1607 if (gc
->set_single_ended
) {
1608 ret
= gc
->set_single_ended(gc
, gpio_chip_hwgpio(desc
),
1609 LINE_MODE_OPEN_SOURCE
);
1611 goto set_output_value
;
1613 /* Emulate open source by not actively driving the line low */
1615 return gpiod_direction_input(desc
);
1617 /* Make sure to disable open drain/source hardware, if any */
1618 if (gc
->set_single_ended
)
1619 gc
->set_single_ended(gc
,
1620 gpio_chip_hwgpio(desc
),
1621 LINE_MODE_PUSH_PULL
);
1625 if (!gc
->set
|| !gc
->direction_output
) {
1627 "%s: missing set() or direction_output() operations\n",
1632 ret
= gc
->direction_output(gc
, gpio_chip_hwgpio(desc
), value
);
1634 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1635 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1636 trace_gpio_direction(desc_to_gpio(desc
), 0, ret
);
1641 * gpiod_direction_output_raw - set the GPIO direction to output
1642 * @desc: GPIO to set to output
1643 * @value: initial output value of the GPIO
1645 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1646 * be called safely on it. The initial value of the output must be specified
1647 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1649 * Return 0 in case of success, else an error code.
1651 int gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1653 VALIDATE_DESC(desc
);
1654 return _gpiod_direction_output_raw(desc
, value
);
1656 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw
);
1659 * gpiod_direction_output - set the GPIO direction to output
1660 * @desc: GPIO to set to output
1661 * @value: initial output value of the GPIO
1663 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1664 * be called safely on it. The initial value of the output must be specified
1665 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1668 * Return 0 in case of success, else an error code.
1670 int gpiod_direction_output(struct gpio_desc
*desc
, int value
)
1672 VALIDATE_DESC(desc
);
1673 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1675 return _gpiod_direction_output_raw(desc
, value
);
1677 EXPORT_SYMBOL_GPL(gpiod_direction_output
);
1680 * gpiod_set_debounce - sets @debounce time for a @gpio
1681 * @gpio: the gpio to set debounce time
1682 * @debounce: debounce time is microseconds
1684 * returns -ENOTSUPP if the controller does not support setting
1687 int gpiod_set_debounce(struct gpio_desc
*desc
, unsigned debounce
)
1689 struct gpio_chip
*chip
;
1691 VALIDATE_DESC(desc
);
1692 chip
= desc
->gdev
->chip
;
1693 if (!chip
->set
|| !chip
->set_debounce
) {
1695 "%s: missing set() or set_debounce() operations\n",
1700 return chip
->set_debounce(chip
, gpio_chip_hwgpio(desc
), debounce
);
1702 EXPORT_SYMBOL_GPL(gpiod_set_debounce
);
1705 * gpiod_is_active_low - test whether a GPIO is active-low or not
1706 * @desc: the gpio descriptor to test
1708 * Returns 1 if the GPIO is active-low, 0 otherwise.
1710 int gpiod_is_active_low(const struct gpio_desc
*desc
)
1712 VALIDATE_DESC(desc
);
1713 return test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1715 EXPORT_SYMBOL_GPL(gpiod_is_active_low
);
1717 /* I/O calls are only valid after configuration completed; the relevant
1718 * "is this a valid GPIO" error checks should already have been done.
1720 * "Get" operations are often inlinable as reading a pin value register,
1721 * and masking the relevant bit in that register.
1723 * When "set" operations are inlinable, they involve writing that mask to
1724 * one register to set a low value, or a different register to set it high.
1725 * Otherwise locking is needed, so there may be little value to inlining.
1727 *------------------------------------------------------------------------
1729 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1730 * have requested the GPIO. That can include implicit requesting by
1731 * a direction setting call. Marking a gpio as requested locks its chip
1732 * in memory, guaranteeing that these table lookups need no more locking
1733 * and that gpiochip_remove() will fail.
1735 * REVISIT when debugging, consider adding some instrumentation to ensure
1736 * that the GPIO was actually requested.
1739 static int _gpiod_get_raw_value(const struct gpio_desc
*desc
)
1741 struct gpio_chip
*chip
;
1745 chip
= desc
->gdev
->chip
;
1746 offset
= gpio_chip_hwgpio(desc
);
1747 value
= chip
->get
? chip
->get(chip
, offset
) : -EIO
;
1748 value
= value
< 0 ? value
: !!value
;
1749 trace_gpio_value(desc_to_gpio(desc
), 1, value
);
1754 * gpiod_get_raw_value() - return a gpio's raw value
1755 * @desc: gpio whose value will be returned
1757 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1758 * its ACTIVE_LOW status, or negative errno on failure.
1760 * This function should be called from contexts where we cannot sleep, and will
1761 * complain if the GPIO chip functions potentially sleep.
1763 int gpiod_get_raw_value(const struct gpio_desc
*desc
)
1765 VALIDATE_DESC(desc
);
1766 /* Should be using gpio_get_value_cansleep() */
1767 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1768 return _gpiod_get_raw_value(desc
);
1770 EXPORT_SYMBOL_GPL(gpiod_get_raw_value
);
1773 * gpiod_get_value() - return a gpio's value
1774 * @desc: gpio whose value will be returned
1776 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1777 * account, or negative errno on failure.
1779 * This function should be called from contexts where we cannot sleep, and will
1780 * complain if the GPIO chip functions potentially sleep.
1782 int gpiod_get_value(const struct gpio_desc
*desc
)
1786 VALIDATE_DESC(desc
);
1787 /* Should be using gpio_get_value_cansleep() */
1788 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1790 value
= _gpiod_get_raw_value(desc
);
1794 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1799 EXPORT_SYMBOL_GPL(gpiod_get_value
);
1802 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1803 * @desc: gpio descriptor whose state need to be set.
1804 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1806 static void _gpio_set_open_drain_value(struct gpio_desc
*desc
, bool value
)
1809 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1810 int offset
= gpio_chip_hwgpio(desc
);
1813 err
= chip
->direction_input(chip
, offset
);
1815 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1817 err
= chip
->direction_output(chip
, offset
, 0);
1819 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1821 trace_gpio_direction(desc_to_gpio(desc
), value
, err
);
1824 "%s: Error in set_value for open drain err %d\n",
1829 * _gpio_set_open_source_value() - Set the open source gpio's value.
1830 * @desc: gpio descriptor whose state need to be set.
1831 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1833 static void _gpio_set_open_source_value(struct gpio_desc
*desc
, bool value
)
1836 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1837 int offset
= gpio_chip_hwgpio(desc
);
1840 err
= chip
->direction_output(chip
, offset
, 1);
1842 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1844 err
= chip
->direction_input(chip
, offset
);
1846 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1848 trace_gpio_direction(desc_to_gpio(desc
), !value
, err
);
1851 "%s: Error in set_value for open source err %d\n",
1855 static void _gpiod_set_raw_value(struct gpio_desc
*desc
, bool value
)
1857 struct gpio_chip
*chip
;
1859 chip
= desc
->gdev
->chip
;
1860 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1861 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
1862 _gpio_set_open_drain_value(desc
, value
);
1863 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
1864 _gpio_set_open_source_value(desc
, value
);
1866 chip
->set(chip
, gpio_chip_hwgpio(desc
), value
);
1870 * set multiple outputs on the same chip;
1871 * use the chip's set_multiple function if available;
1872 * otherwise set the outputs sequentially;
1873 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1874 * defines which outputs are to be changed
1875 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1876 * defines the values the outputs specified by mask are to be set to
1878 static void gpio_chip_set_multiple(struct gpio_chip
*chip
,
1879 unsigned long *mask
, unsigned long *bits
)
1881 if (chip
->set_multiple
) {
1882 chip
->set_multiple(chip
, mask
, bits
);
1885 for (i
= 0; i
< chip
->ngpio
; i
++) {
1886 if (mask
[BIT_WORD(i
)] == 0) {
1887 /* no more set bits in this mask word;
1888 * skip ahead to the next word */
1889 i
= (BIT_WORD(i
) + 1) * BITS_PER_LONG
- 1;
1892 /* set outputs if the corresponding mask bit is set */
1893 if (__test_and_clear_bit(i
, mask
))
1894 chip
->set(chip
, i
, test_bit(i
, bits
));
1899 void gpiod_set_array_value_complex(bool raw
, bool can_sleep
,
1900 unsigned int array_size
,
1901 struct gpio_desc
**desc_array
,
1906 while (i
< array_size
) {
1907 struct gpio_chip
*chip
= desc_array
[i
]->gdev
->chip
;
1908 unsigned long mask
[BITS_TO_LONGS(chip
->ngpio
)];
1909 unsigned long bits
[BITS_TO_LONGS(chip
->ngpio
)];
1913 WARN_ON(chip
->can_sleep
);
1915 memset(mask
, 0, sizeof(mask
));
1917 struct gpio_desc
*desc
= desc_array
[i
];
1918 int hwgpio
= gpio_chip_hwgpio(desc
);
1919 int value
= value_array
[i
];
1921 if (!raw
&& test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1923 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1925 * collect all normal outputs belonging to the same chip
1926 * open drain and open source outputs are set individually
1928 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
1929 _gpio_set_open_drain_value(desc
, value
);
1930 } else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
1931 _gpio_set_open_source_value(desc
, value
);
1933 __set_bit(hwgpio
, mask
);
1935 __set_bit(hwgpio
, bits
);
1937 __clear_bit(hwgpio
, bits
);
1941 } while ((i
< array_size
) &&
1942 (desc_array
[i
]->gdev
->chip
== chip
));
1943 /* push collected bits to outputs */
1945 gpio_chip_set_multiple(chip
, mask
, bits
);
1950 * gpiod_set_raw_value() - assign a gpio's raw value
1951 * @desc: gpio whose value will be assigned
1952 * @value: value to assign
1954 * Set the raw value of the GPIO, i.e. the value of its physical line without
1955 * regard for its ACTIVE_LOW status.
1957 * This function should be called from contexts where we cannot sleep, and will
1958 * complain if the GPIO chip functions potentially sleep.
1960 void gpiod_set_raw_value(struct gpio_desc
*desc
, int value
)
1962 VALIDATE_DESC_VOID(desc
);
1963 /* Should be using gpiod_set_value_cansleep() */
1964 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1965 _gpiod_set_raw_value(desc
, value
);
1967 EXPORT_SYMBOL_GPL(gpiod_set_raw_value
);
1970 * gpiod_set_value() - assign a gpio's value
1971 * @desc: gpio whose value will be assigned
1972 * @value: value to assign
1974 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1977 * This function should be called from contexts where we cannot sleep, and will
1978 * complain if the GPIO chip functions potentially sleep.
1980 void gpiod_set_value(struct gpio_desc
*desc
, int value
)
1982 VALIDATE_DESC_VOID(desc
);
1983 /* Should be using gpiod_set_value_cansleep() */
1984 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1985 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1987 _gpiod_set_raw_value(desc
, value
);
1989 EXPORT_SYMBOL_GPL(gpiod_set_value
);
1992 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1993 * @array_size: number of elements in the descriptor / value arrays
1994 * @desc_array: array of GPIO descriptors whose values will be assigned
1995 * @value_array: array of values to assign
1997 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1998 * without regard for their ACTIVE_LOW status.
2000 * This function should be called from contexts where we cannot sleep, and will
2001 * complain if the GPIO chip functions potentially sleep.
2003 void gpiod_set_raw_array_value(unsigned int array_size
,
2004 struct gpio_desc
**desc_array
, int *value_array
)
2008 gpiod_set_array_value_complex(true, false, array_size
, desc_array
,
2011 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value
);
2014 * gpiod_set_array_value() - assign values to an array of GPIOs
2015 * @array_size: number of elements in the descriptor / value arrays
2016 * @desc_array: array of GPIO descriptors whose values will be assigned
2017 * @value_array: array of values to assign
2019 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2022 * This function should be called from contexts where we cannot sleep, and will
2023 * complain if the GPIO chip functions potentially sleep.
2025 void gpiod_set_array_value(unsigned int array_size
,
2026 struct gpio_desc
**desc_array
, int *value_array
)
2030 gpiod_set_array_value_complex(false, false, array_size
, desc_array
,
2033 EXPORT_SYMBOL_GPL(gpiod_set_array_value
);
2036 * gpiod_cansleep() - report whether gpio value access may sleep
2037 * @desc: gpio to check
2040 int gpiod_cansleep(const struct gpio_desc
*desc
)
2042 VALIDATE_DESC(desc
);
2043 return desc
->gdev
->chip
->can_sleep
;
2045 EXPORT_SYMBOL_GPL(gpiod_cansleep
);
2048 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2049 * @desc: gpio whose IRQ will be returned (already requested)
2051 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2054 int gpiod_to_irq(const struct gpio_desc
*desc
)
2056 struct gpio_chip
*chip
;
2059 VALIDATE_DESC(desc
);
2060 chip
= desc
->gdev
->chip
;
2061 offset
= gpio_chip_hwgpio(desc
);
2063 int retirq
= chip
->to_irq(chip
, offset
);
2065 /* Zero means NO_IRQ */
2073 EXPORT_SYMBOL_GPL(gpiod_to_irq
);
2076 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2077 * @chip: the chip the GPIO to lock belongs to
2078 * @offset: the offset of the GPIO to lock as IRQ
2080 * This is used directly by GPIO drivers that want to lock down
2081 * a certain GPIO line to be used for IRQs.
2083 int gpiochip_lock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2085 struct gpio_desc
*desc
;
2087 desc
= gpiochip_get_desc(chip
, offset
);
2089 return PTR_ERR(desc
);
2091 /* Flush direction if something changed behind our back */
2092 if (chip
->get_direction
) {
2093 int dir
= chip
->get_direction(chip
, offset
);
2096 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
2098 set_bit(FLAG_IS_OUT
, &desc
->flags
);
2101 if (test_bit(FLAG_IS_OUT
, &desc
->flags
)) {
2103 "%s: tried to flag a GPIO set as output for IRQ\n",
2108 set_bit(FLAG_USED_AS_IRQ
, &desc
->flags
);
2111 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq
);
2114 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2115 * @chip: the chip the GPIO to lock belongs to
2116 * @offset: the offset of the GPIO to lock as IRQ
2118 * This is used directly by GPIO drivers that want to indicate
2119 * that a certain GPIO is no longer used exclusively for IRQ.
2121 void gpiochip_unlock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2123 if (offset
>= chip
->ngpio
)
2126 clear_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2128 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq
);
2130 bool gpiochip_line_is_irq(struct gpio_chip
*chip
, unsigned int offset
)
2132 if (offset
>= chip
->ngpio
)
2135 return test_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2137 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq
);
2139 bool gpiochip_line_is_open_drain(struct gpio_chip
*chip
, unsigned int offset
)
2141 if (offset
>= chip
->ngpio
)
2144 return test_bit(FLAG_OPEN_DRAIN
, &chip
->gpiodev
->descs
[offset
].flags
);
2146 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain
);
2148 bool gpiochip_line_is_open_source(struct gpio_chip
*chip
, unsigned int offset
)
2150 if (offset
>= chip
->ngpio
)
2153 return test_bit(FLAG_OPEN_SOURCE
, &chip
->gpiodev
->descs
[offset
].flags
);
2155 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source
);
2158 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2159 * @desc: gpio whose value will be returned
2161 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2162 * its ACTIVE_LOW status, or negative errno on failure.
2164 * This function is to be called from contexts that can sleep.
2166 int gpiod_get_raw_value_cansleep(const struct gpio_desc
*desc
)
2168 might_sleep_if(extra_checks
);
2169 VALIDATE_DESC(desc
);
2170 return _gpiod_get_raw_value(desc
);
2172 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep
);
2175 * gpiod_get_value_cansleep() - return a gpio's value
2176 * @desc: gpio whose value will be returned
2178 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2179 * account, or negative errno on failure.
2181 * This function is to be called from contexts that can sleep.
2183 int gpiod_get_value_cansleep(const struct gpio_desc
*desc
)
2187 might_sleep_if(extra_checks
);
2188 VALIDATE_DESC(desc
);
2189 value
= _gpiod_get_raw_value(desc
);
2193 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2198 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep
);
2201 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2202 * @desc: gpio whose value will be assigned
2203 * @value: value to assign
2205 * Set the raw value of the GPIO, i.e. the value of its physical line without
2206 * regard for its ACTIVE_LOW status.
2208 * This function is to be called from contexts that can sleep.
2210 void gpiod_set_raw_value_cansleep(struct gpio_desc
*desc
, int value
)
2212 might_sleep_if(extra_checks
);
2213 VALIDATE_DESC_VOID(desc
);
2214 _gpiod_set_raw_value(desc
, value
);
2216 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep
);
2219 * gpiod_set_value_cansleep() - assign a gpio's value
2220 * @desc: gpio whose value will be assigned
2221 * @value: value to assign
2223 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2226 * This function is to be called from contexts that can sleep.
2228 void gpiod_set_value_cansleep(struct gpio_desc
*desc
, int value
)
2230 might_sleep_if(extra_checks
);
2231 VALIDATE_DESC_VOID(desc
);
2232 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2234 _gpiod_set_raw_value(desc
, value
);
2236 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep
);
2239 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2240 * @array_size: number of elements in the descriptor / value arrays
2241 * @desc_array: array of GPIO descriptors whose values will be assigned
2242 * @value_array: array of values to assign
2244 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2245 * without regard for their ACTIVE_LOW status.
2247 * This function is to be called from contexts that can sleep.
2249 void gpiod_set_raw_array_value_cansleep(unsigned int array_size
,
2250 struct gpio_desc
**desc_array
,
2253 might_sleep_if(extra_checks
);
2256 gpiod_set_array_value_complex(true, true, array_size
, desc_array
,
2259 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep
);
2262 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2263 * @array_size: number of elements in the descriptor / value arrays
2264 * @desc_array: array of GPIO descriptors whose values will be assigned
2265 * @value_array: array of values to assign
2267 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2270 * This function is to be called from contexts that can sleep.
2272 void gpiod_set_array_value_cansleep(unsigned int array_size
,
2273 struct gpio_desc
**desc_array
,
2276 might_sleep_if(extra_checks
);
2279 gpiod_set_array_value_complex(false, true, array_size
, desc_array
,
2282 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep
);
2285 * gpiod_add_lookup_table() - register GPIO device consumers
2286 * @table: table of consumers to register
2288 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
)
2290 mutex_lock(&gpio_lookup_lock
);
2292 list_add_tail(&table
->list
, &gpio_lookup_list
);
2294 mutex_unlock(&gpio_lookup_lock
);
2298 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2299 * @table: table of consumers to unregister
2301 void gpiod_remove_lookup_table(struct gpiod_lookup_table
*table
)
2303 mutex_lock(&gpio_lookup_lock
);
2305 list_del(&table
->list
);
2307 mutex_unlock(&gpio_lookup_lock
);
2310 static struct gpio_desc
*of_find_gpio(struct device
*dev
, const char *con_id
,
2312 enum gpio_lookup_flags
*flags
)
2314 char prop_name
[32]; /* 32 is max size of property name */
2315 enum of_gpio_flags of_flags
;
2316 struct gpio_desc
*desc
;
2319 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2321 snprintf(prop_name
, sizeof(prop_name
), "%s-%s", con_id
,
2324 snprintf(prop_name
, sizeof(prop_name
), "%s",
2327 desc
= of_get_named_gpiod_flags(dev
->of_node
, prop_name
, idx
,
2329 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2336 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2337 *flags
|= GPIO_ACTIVE_LOW
;
2339 if (of_flags
& OF_GPIO_SINGLE_ENDED
) {
2340 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2341 *flags
|= GPIO_OPEN_DRAIN
;
2343 *flags
|= GPIO_OPEN_SOURCE
;
2349 static struct gpio_desc
*acpi_find_gpio(struct device
*dev
,
2352 enum gpiod_flags flags
,
2353 enum gpio_lookup_flags
*lookupflags
)
2355 struct acpi_device
*adev
= ACPI_COMPANION(dev
);
2356 struct acpi_gpio_info info
;
2357 struct gpio_desc
*desc
;
2361 /* Try first from _DSD */
2362 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2363 if (con_id
&& strcmp(con_id
, "gpios")) {
2364 snprintf(propname
, sizeof(propname
), "%s-%s",
2365 con_id
, gpio_suffixes
[i
]);
2367 snprintf(propname
, sizeof(propname
), "%s",
2371 desc
= acpi_get_gpiod_by_index(adev
, propname
, idx
, &info
);
2372 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2376 /* Then from plain _CRS GPIOs */
2378 if (!acpi_can_fallback_to_crs(adev
, con_id
))
2379 return ERR_PTR(-ENOENT
);
2381 desc
= acpi_get_gpiod_by_index(adev
, NULL
, idx
, &info
);
2385 if ((flags
== GPIOD_OUT_LOW
|| flags
== GPIOD_OUT_HIGH
) &&
2387 dev_dbg(dev
, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
2388 return ERR_PTR(-ENOENT
);
2392 if (info
.polarity
== GPIO_ACTIVE_LOW
)
2393 *lookupflags
|= GPIO_ACTIVE_LOW
;
2398 static struct gpiod_lookup_table
*gpiod_find_lookup_table(struct device
*dev
)
2400 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
2401 struct gpiod_lookup_table
*table
;
2403 mutex_lock(&gpio_lookup_lock
);
2405 list_for_each_entry(table
, &gpio_lookup_list
, list
) {
2406 if (table
->dev_id
&& dev_id
) {
2408 * Valid strings on both ends, must be identical to have
2411 if (!strcmp(table
->dev_id
, dev_id
))
2415 * One of the pointers is NULL, so both must be to have
2418 if (dev_id
== table
->dev_id
)
2425 mutex_unlock(&gpio_lookup_lock
);
2429 static struct gpio_desc
*gpiod_find(struct device
*dev
, const char *con_id
,
2431 enum gpio_lookup_flags
*flags
)
2433 struct gpio_desc
*desc
= ERR_PTR(-ENOENT
);
2434 struct gpiod_lookup_table
*table
;
2435 struct gpiod_lookup
*p
;
2437 table
= gpiod_find_lookup_table(dev
);
2441 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2442 struct gpio_chip
*chip
;
2444 /* idx must always match exactly */
2448 /* If the lookup entry has a con_id, require exact match */
2449 if (p
->con_id
&& (!con_id
|| strcmp(p
->con_id
, con_id
)))
2452 chip
= find_chip_by_name(p
->chip_label
);
2455 dev_err(dev
, "cannot find GPIO chip %s\n",
2457 return ERR_PTR(-ENODEV
);
2460 if (chip
->ngpio
<= p
->chip_hwnum
) {
2462 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2463 idx
, chip
->ngpio
, chip
->label
);
2464 return ERR_PTR(-EINVAL
);
2467 desc
= gpiochip_get_desc(chip
, p
->chip_hwnum
);
2476 static int dt_gpio_count(struct device
*dev
, const char *con_id
)
2482 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2484 snprintf(propname
, sizeof(propname
), "%s-%s",
2485 con_id
, gpio_suffixes
[i
]);
2487 snprintf(propname
, sizeof(propname
), "%s",
2490 ret
= of_gpio_named_count(dev
->of_node
, propname
);
2497 static int platform_gpio_count(struct device
*dev
, const char *con_id
)
2499 struct gpiod_lookup_table
*table
;
2500 struct gpiod_lookup
*p
;
2501 unsigned int count
= 0;
2503 table
= gpiod_find_lookup_table(dev
);
2507 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2508 if ((con_id
&& p
->con_id
&& !strcmp(con_id
, p
->con_id
)) ||
2509 (!con_id
&& !p
->con_id
))
2519 * gpiod_count - return the number of GPIOs associated with a device / function
2520 * or -ENOENT if no GPIO has been assigned to the requested function
2521 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2522 * @con_id: function within the GPIO consumer
2524 int gpiod_count(struct device
*dev
, const char *con_id
)
2526 int count
= -ENOENT
;
2528 if (IS_ENABLED(CONFIG_OF
) && dev
&& dev
->of_node
)
2529 count
= dt_gpio_count(dev
, con_id
);
2530 else if (IS_ENABLED(CONFIG_ACPI
) && dev
&& ACPI_HANDLE(dev
))
2531 count
= acpi_gpio_count(dev
, con_id
);
2534 count
= platform_gpio_count(dev
, con_id
);
2538 EXPORT_SYMBOL_GPL(gpiod_count
);
2541 * gpiod_get - obtain a GPIO for a given GPIO function
2542 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2543 * @con_id: function within the GPIO consumer
2544 * @flags: optional GPIO initialization flags
2546 * Return the GPIO descriptor corresponding to the function con_id of device
2547 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2548 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2550 struct gpio_desc
*__must_check
gpiod_get(struct device
*dev
, const char *con_id
,
2551 enum gpiod_flags flags
)
2553 return gpiod_get_index(dev
, con_id
, 0, flags
);
2555 EXPORT_SYMBOL_GPL(gpiod_get
);
2558 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2559 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2560 * @con_id: function within the GPIO consumer
2561 * @flags: optional GPIO initialization flags
2563 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2564 * the requested function it will return NULL. This is convenient for drivers
2565 * that need to handle optional GPIOs.
2567 struct gpio_desc
*__must_check
gpiod_get_optional(struct device
*dev
,
2569 enum gpiod_flags flags
)
2571 return gpiod_get_index_optional(dev
, con_id
, 0, flags
);
2573 EXPORT_SYMBOL_GPL(gpiod_get_optional
);
2576 * gpiod_parse_flags - helper function to parse GPIO lookup flags
2577 * @desc: gpio to be setup
2578 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2581 * Set the GPIO descriptor flags based on the given GPIO lookup flags.
2583 static void gpiod_parse_flags(struct gpio_desc
*desc
, unsigned long lflags
)
2585 if (lflags
& GPIO_ACTIVE_LOW
)
2586 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2587 if (lflags
& GPIO_OPEN_DRAIN
)
2588 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2589 if (lflags
& GPIO_OPEN_SOURCE
)
2590 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2594 * gpiod_configure_flags - helper function to configure a given GPIO
2595 * @desc: gpio whose value will be assigned
2596 * @con_id: function within the GPIO consumer
2597 * @dflags: gpiod_flags - optional GPIO initialization flags
2599 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2600 * requested function and/or index, or another IS_ERR() code if an error
2601 * occurred while trying to acquire the GPIO.
2603 static int gpiod_configure_flags(struct gpio_desc
*desc
, const char *con_id
,
2604 enum gpiod_flags dflags
)
2608 /* No particular flag request, return here... */
2609 if (!(dflags
& GPIOD_FLAGS_BIT_DIR_SET
)) {
2610 pr_debug("no flags found for %s\n", con_id
);
2615 if (dflags
& GPIOD_FLAGS_BIT_DIR_OUT
)
2616 status
= gpiod_direction_output(desc
,
2617 dflags
& GPIOD_FLAGS_BIT_DIR_VAL
);
2619 status
= gpiod_direction_input(desc
);
2625 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2626 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2627 * @con_id: function within the GPIO consumer
2628 * @idx: index of the GPIO to obtain in the consumer
2629 * @flags: optional GPIO initialization flags
2631 * This variant of gpiod_get() allows to access GPIOs other than the first
2632 * defined one for functions that define several GPIOs.
2634 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2635 * requested function and/or index, or another IS_ERR() code if an error
2636 * occurred while trying to acquire the GPIO.
2638 struct gpio_desc
*__must_check
gpiod_get_index(struct device
*dev
,
2641 enum gpiod_flags flags
)
2643 struct gpio_desc
*desc
= NULL
;
2645 enum gpio_lookup_flags lookupflags
= 0;
2647 dev_dbg(dev
, "GPIO lookup for consumer %s\n", con_id
);
2650 /* Using device tree? */
2651 if (IS_ENABLED(CONFIG_OF
) && dev
->of_node
) {
2652 dev_dbg(dev
, "using device tree for GPIO lookup\n");
2653 desc
= of_find_gpio(dev
, con_id
, idx
, &lookupflags
);
2654 } else if (ACPI_COMPANION(dev
)) {
2655 dev_dbg(dev
, "using ACPI for GPIO lookup\n");
2656 desc
= acpi_find_gpio(dev
, con_id
, idx
, flags
, &lookupflags
);
2661 * Either we are not using DT or ACPI, or their lookup did not return
2662 * a result. In that case, use platform lookup as a fallback.
2664 if (!desc
|| desc
== ERR_PTR(-ENOENT
)) {
2665 dev_dbg(dev
, "using lookup tables for GPIO lookup\n");
2666 desc
= gpiod_find(dev
, con_id
, idx
, &lookupflags
);
2670 dev_dbg(dev
, "lookup for GPIO %s failed\n", con_id
);
2674 gpiod_parse_flags(desc
, lookupflags
);
2676 status
= gpiod_request(desc
, con_id
);
2678 return ERR_PTR(status
);
2680 status
= gpiod_configure_flags(desc
, con_id
, flags
);
2682 dev_dbg(dev
, "setup of GPIO %s failed\n", con_id
);
2684 return ERR_PTR(status
);
2689 EXPORT_SYMBOL_GPL(gpiod_get_index
);
2692 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2693 * @fwnode: handle of the firmware node
2694 * @propname: name of the firmware property representing the GPIO
2696 * This function can be used for drivers that get their configuration
2699 * Function properly finds the corresponding GPIO using whatever is the
2700 * underlying firmware interface and then makes sure that the GPIO
2701 * descriptor is requested before it is returned to the caller.
2703 * In case of error an ERR_PTR() is returned.
2705 struct gpio_desc
*fwnode_get_named_gpiod(struct fwnode_handle
*fwnode
,
2706 const char *propname
)
2708 struct gpio_desc
*desc
= ERR_PTR(-ENODEV
);
2709 bool active_low
= false;
2710 bool single_ended
= false;
2714 return ERR_PTR(-EINVAL
);
2716 if (is_of_node(fwnode
)) {
2717 enum of_gpio_flags flags
;
2719 desc
= of_get_named_gpiod_flags(to_of_node(fwnode
), propname
, 0,
2721 if (!IS_ERR(desc
)) {
2722 active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
2723 single_ended
= flags
& OF_GPIO_SINGLE_ENDED
;
2725 } else if (is_acpi_node(fwnode
)) {
2726 struct acpi_gpio_info info
;
2728 desc
= acpi_node_get_gpiod(fwnode
, propname
, 0, &info
);
2730 active_low
= info
.polarity
== GPIO_ACTIVE_LOW
;
2737 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2741 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2743 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2746 ret
= gpiod_request(desc
, NULL
);
2748 return ERR_PTR(ret
);
2752 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod
);
2755 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2757 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2758 * @con_id: function within the GPIO consumer
2759 * @index: index of the GPIO to obtain in the consumer
2760 * @flags: optional GPIO initialization flags
2762 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2763 * specified index was assigned to the requested function it will return NULL.
2764 * This is convenient for drivers that need to handle optional GPIOs.
2766 struct gpio_desc
*__must_check
gpiod_get_index_optional(struct device
*dev
,
2769 enum gpiod_flags flags
)
2771 struct gpio_desc
*desc
;
2773 desc
= gpiod_get_index(dev
, con_id
, index
, flags
);
2775 if (PTR_ERR(desc
) == -ENOENT
)
2781 EXPORT_SYMBOL_GPL(gpiod_get_index_optional
);
2784 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2785 * @desc: gpio whose value will be assigned
2786 * @name: gpio line name
2787 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2789 * @dflags: gpiod_flags - optional GPIO initialization flags
2791 int gpiod_hog(struct gpio_desc
*desc
, const char *name
,
2792 unsigned long lflags
, enum gpiod_flags dflags
)
2794 struct gpio_chip
*chip
;
2795 struct gpio_desc
*local_desc
;
2799 chip
= gpiod_to_chip(desc
);
2800 hwnum
= gpio_chip_hwgpio(desc
);
2802 gpiod_parse_flags(desc
, lflags
);
2804 local_desc
= gpiochip_request_own_desc(chip
, hwnum
, name
);
2805 if (IS_ERR(local_desc
)) {
2806 status
= PTR_ERR(local_desc
);
2807 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
2808 name
, chip
->label
, hwnum
, status
);
2812 status
= gpiod_configure_flags(desc
, name
, dflags
);
2814 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
2815 name
, chip
->label
, hwnum
, status
);
2816 gpiochip_free_own_desc(desc
);
2820 /* Mark GPIO as hogged so it can be identified and removed later */
2821 set_bit(FLAG_IS_HOGGED
, &desc
->flags
);
2823 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2824 desc_to_gpio(desc
), name
,
2825 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ? "output" : "input",
2826 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ?
2827 (dflags
&GPIOD_FLAGS_BIT_DIR_VAL
) ? "/high" : "/low":"");
2833 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2834 * @chip: gpio chip to act on
2836 * This is only used by of_gpiochip_remove to free hogged gpios
2838 static void gpiochip_free_hogs(struct gpio_chip
*chip
)
2842 for (id
= 0; id
< chip
->ngpio
; id
++) {
2843 if (test_bit(FLAG_IS_HOGGED
, &chip
->gpiodev
->descs
[id
].flags
))
2844 gpiochip_free_own_desc(&chip
->gpiodev
->descs
[id
]);
2849 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2850 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2851 * @con_id: function within the GPIO consumer
2852 * @flags: optional GPIO initialization flags
2854 * This function acquires all the GPIOs defined under a given function.
2856 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2857 * no GPIO has been assigned to the requested function, or another IS_ERR()
2858 * code if an error occurred while trying to acquire the GPIOs.
2860 struct gpio_descs
*__must_check
gpiod_get_array(struct device
*dev
,
2862 enum gpiod_flags flags
)
2864 struct gpio_desc
*desc
;
2865 struct gpio_descs
*descs
;
2868 count
= gpiod_count(dev
, con_id
);
2870 return ERR_PTR(count
);
2872 descs
= kzalloc(sizeof(*descs
) + sizeof(descs
->desc
[0]) * count
,
2875 return ERR_PTR(-ENOMEM
);
2877 for (descs
->ndescs
= 0; descs
->ndescs
< count
; ) {
2878 desc
= gpiod_get_index(dev
, con_id
, descs
->ndescs
, flags
);
2880 gpiod_put_array(descs
);
2881 return ERR_CAST(desc
);
2883 descs
->desc
[descs
->ndescs
] = desc
;
2888 EXPORT_SYMBOL_GPL(gpiod_get_array
);
2891 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2893 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2894 * @con_id: function within the GPIO consumer
2895 * @flags: optional GPIO initialization flags
2897 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2898 * assigned to the requested function it will return NULL.
2900 struct gpio_descs
*__must_check
gpiod_get_array_optional(struct device
*dev
,
2902 enum gpiod_flags flags
)
2904 struct gpio_descs
*descs
;
2906 descs
= gpiod_get_array(dev
, con_id
, flags
);
2907 if (IS_ERR(descs
) && (PTR_ERR(descs
) == -ENOENT
))
2912 EXPORT_SYMBOL_GPL(gpiod_get_array_optional
);
2915 * gpiod_put - dispose of a GPIO descriptor
2916 * @desc: GPIO descriptor to dispose of
2918 * No descriptor can be used after gpiod_put() has been called on it.
2920 void gpiod_put(struct gpio_desc
*desc
)
2924 EXPORT_SYMBOL_GPL(gpiod_put
);
2927 * gpiod_put_array - dispose of multiple GPIO descriptors
2928 * @descs: struct gpio_descs containing an array of descriptors
2930 void gpiod_put_array(struct gpio_descs
*descs
)
2934 for (i
= 0; i
< descs
->ndescs
; i
++)
2935 gpiod_put(descs
->desc
[i
]);
2939 EXPORT_SYMBOL_GPL(gpiod_put_array
);
2941 static int __init
gpiolib_dev_init(void)
2945 /* Register GPIO sysfs bus */
2946 ret
= bus_register(&gpio_bus_type
);
2948 pr_err("gpiolib: could not register GPIO bus type\n");
2952 ret
= alloc_chrdev_region(&gpio_devt
, 0, GPIO_DEV_MAX
, "gpiochip");
2954 pr_err("gpiolib: failed to allocate char dev region\n");
2955 bus_unregister(&gpio_bus_type
);
2957 gpiolib_initialized
= true;
2958 gpiochip_setup_devs();
2962 core_initcall(gpiolib_dev_init
);
2964 #ifdef CONFIG_DEBUG_FS
2966 static void gpiolib_dbg_show(struct seq_file
*s
, struct gpio_device
*gdev
)
2969 struct gpio_chip
*chip
= gdev
->chip
;
2970 unsigned gpio
= gdev
->base
;
2971 struct gpio_desc
*gdesc
= &gdev
->descs
[0];
2975 for (i
= 0; i
< gdev
->ngpio
; i
++, gpio
++, gdesc
++) {
2976 if (!test_bit(FLAG_REQUESTED
, &gdesc
->flags
)) {
2978 seq_printf(s
, " gpio-%-3d (%-20.20s)\n",
2984 gpiod_get_direction(gdesc
);
2985 is_out
= test_bit(FLAG_IS_OUT
, &gdesc
->flags
);
2986 is_irq
= test_bit(FLAG_USED_AS_IRQ
, &gdesc
->flags
);
2987 seq_printf(s
, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2988 gpio
, gdesc
->name
? gdesc
->name
: "", gdesc
->label
,
2989 is_out
? "out" : "in ",
2991 ? (chip
->get(chip
, i
) ? "hi" : "lo")
2993 is_irq
? "IRQ" : " ");
2994 seq_printf(s
, "\n");
2998 static void *gpiolib_seq_start(struct seq_file
*s
, loff_t
*pos
)
3000 unsigned long flags
;
3001 struct gpio_device
*gdev
= NULL
;
3002 loff_t index
= *pos
;
3006 spin_lock_irqsave(&gpio_lock
, flags
);
3007 list_for_each_entry(gdev
, &gpio_devices
, list
)
3009 spin_unlock_irqrestore(&gpio_lock
, flags
);
3012 spin_unlock_irqrestore(&gpio_lock
, flags
);
3017 static void *gpiolib_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
3019 unsigned long flags
;
3020 struct gpio_device
*gdev
= v
;
3023 spin_lock_irqsave(&gpio_lock
, flags
);
3024 if (list_is_last(&gdev
->list
, &gpio_devices
))
3027 ret
= list_entry(gdev
->list
.next
, struct gpio_device
, list
);
3028 spin_unlock_irqrestore(&gpio_lock
, flags
);
3036 static void gpiolib_seq_stop(struct seq_file
*s
, void *v
)
3040 static int gpiolib_seq_show(struct seq_file
*s
, void *v
)
3042 struct gpio_device
*gdev
= v
;
3043 struct gpio_chip
*chip
= gdev
->chip
;
3044 struct device
*parent
;
3047 seq_printf(s
, "%s%s: (dangling chip)", (char *)s
->private,
3048 dev_name(&gdev
->dev
));
3052 seq_printf(s
, "%s%s: GPIOs %d-%d", (char *)s
->private,
3053 dev_name(&gdev
->dev
),
3054 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1);
3055 parent
= chip
->parent
;
3057 seq_printf(s
, ", parent: %s/%s",
3058 parent
->bus
? parent
->bus
->name
: "no-bus",
3061 seq_printf(s
, ", %s", chip
->label
);
3062 if (chip
->can_sleep
)
3063 seq_printf(s
, ", can sleep");
3064 seq_printf(s
, ":\n");
3067 chip
->dbg_show(s
, chip
);
3069 gpiolib_dbg_show(s
, gdev
);
3074 static const struct seq_operations gpiolib_seq_ops
= {
3075 .start
= gpiolib_seq_start
,
3076 .next
= gpiolib_seq_next
,
3077 .stop
= gpiolib_seq_stop
,
3078 .show
= gpiolib_seq_show
,
3081 static int gpiolib_open(struct inode
*inode
, struct file
*file
)
3083 return seq_open(file
, &gpiolib_seq_ops
);
3086 static const struct file_operations gpiolib_operations
= {
3087 .owner
= THIS_MODULE
,
3088 .open
= gpiolib_open
,
3090 .llseek
= seq_lseek
,
3091 .release
= seq_release
,
3094 static int __init
gpiolib_debugfs_init(void)
3096 /* /sys/kernel/debug/gpio */
3097 (void) debugfs_create_file("gpio", S_IFREG
| S_IRUGO
,
3098 NULL
, NULL
, &gpiolib_operations
);
3101 subsys_initcall(gpiolib_debugfs_init
);
3103 #endif /* DEBUG_FS */