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 <uapi/linux/gpio.h>
27 #define CREATE_TRACE_POINTS
28 #include <trace/events/gpio.h>
30 /* Implementation infrastructure for GPIO interfaces.
32 * The GPIO programming interface allows for inlining speed-critical
33 * get/set operations for common cases, so that access to SOC-integrated
34 * GPIOs can sometimes cost only an instruction or two per bit.
38 /* When debugging, extend minimal trust to callers and platform code.
39 * Also emit diagnostic messages that may help initial bringup, when
40 * board setup or driver bugs are most common.
42 * Otherwise, minimize overhead in what may be bitbanging codepaths.
45 #define extra_checks 1
47 #define extra_checks 0
50 /* Device and char device-related information */
51 static DEFINE_IDA(gpio_ida
);
52 static dev_t gpio_devt
;
53 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
54 static struct bus_type gpio_bus_type
= {
58 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
59 * While any GPIO is requested, its gpio_chip is not removable;
60 * each GPIO's "requested" flag serves as a lock and refcount.
62 DEFINE_SPINLOCK(gpio_lock
);
64 static DEFINE_MUTEX(gpio_lookup_lock
);
65 static LIST_HEAD(gpio_lookup_list
);
66 LIST_HEAD(gpio_devices
);
68 static void gpiochip_free_hogs(struct gpio_chip
*chip
);
69 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
);
71 static bool gpiolib_initialized
;
73 static inline void desc_set_label(struct gpio_desc
*d
, const char *label
)
79 * Convert a GPIO number to its descriptor
81 struct gpio_desc
*gpio_to_desc(unsigned gpio
)
83 struct gpio_device
*gdev
;
86 spin_lock_irqsave(&gpio_lock
, flags
);
88 list_for_each_entry(gdev
, &gpio_devices
, list
) {
89 if (gdev
->base
<= gpio
&&
90 gdev
->base
+ gdev
->ngpio
> gpio
) {
91 spin_unlock_irqrestore(&gpio_lock
, flags
);
92 return &gdev
->descs
[gpio
- gdev
->base
];
96 spin_unlock_irqrestore(&gpio_lock
, flags
);
98 if (!gpio_is_valid(gpio
))
99 WARN(1, "invalid GPIO %d\n", gpio
);
103 EXPORT_SYMBOL_GPL(gpio_to_desc
);
106 * Get the GPIO descriptor corresponding to the given hw number for this chip.
108 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
111 struct gpio_device
*gdev
= chip
->gpiodev
;
113 if (hwnum
>= gdev
->ngpio
)
114 return ERR_PTR(-EINVAL
);
116 return &gdev
->descs
[hwnum
];
120 * Convert a GPIO descriptor to the integer namespace.
121 * This should disappear in the future but is needed since we still
122 * use GPIO numbers for error messages and sysfs nodes
124 int desc_to_gpio(const struct gpio_desc
*desc
)
126 return desc
->gdev
->base
+ (desc
- &desc
->gdev
->descs
[0]);
128 EXPORT_SYMBOL_GPL(desc_to_gpio
);
132 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
133 * @desc: descriptor to return the chip of
135 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
137 if (!desc
|| !desc
->gdev
|| !desc
->gdev
->chip
)
139 return desc
->gdev
->chip
;
141 EXPORT_SYMBOL_GPL(gpiod_to_chip
);
143 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
144 static int gpiochip_find_base(int ngpio
)
146 struct gpio_device
*gdev
;
147 int base
= ARCH_NR_GPIOS
- ngpio
;
149 list_for_each_entry_reverse(gdev
, &gpio_devices
, list
) {
150 /* found a free space? */
151 if (gdev
->base
+ gdev
->ngpio
<= base
)
154 /* nope, check the space right before the chip */
155 base
= gdev
->base
- ngpio
;
158 if (gpio_is_valid(base
)) {
159 pr_debug("%s: found new base at %d\n", __func__
, base
);
162 pr_err("%s: cannot find free range\n", __func__
);
168 * gpiod_get_direction - return the current direction of a GPIO
169 * @desc: GPIO to get the direction of
171 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
173 * This function may sleep if gpiod_cansleep() is true.
175 int gpiod_get_direction(struct gpio_desc
*desc
)
177 struct gpio_chip
*chip
;
179 int status
= -EINVAL
;
181 chip
= gpiod_to_chip(desc
);
182 offset
= gpio_chip_hwgpio(desc
);
184 if (!chip
->get_direction
)
187 status
= chip
->get_direction(chip
, offset
);
189 /* GPIOF_DIR_IN, or other positive */
191 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
195 set_bit(FLAG_IS_OUT
, &desc
->flags
);
199 EXPORT_SYMBOL_GPL(gpiod_get_direction
);
202 * Add a new chip to the global chips list, keeping the list of chips sorted
203 * by range(means [base, base + ngpio - 1]) order.
205 * Return -EBUSY if the new chip overlaps with some other chip's integer
208 static int gpiodev_add_to_list(struct gpio_device
*gdev
)
210 struct gpio_device
*prev
, *next
;
212 if (list_empty(&gpio_devices
)) {
213 /* initial entry in list */
214 list_add_tail(&gdev
->list
, &gpio_devices
);
218 next
= list_entry(gpio_devices
.next
, struct gpio_device
, list
);
219 if (gdev
->base
+ gdev
->ngpio
<= next
->base
) {
220 /* add before first entry */
221 list_add(&gdev
->list
, &gpio_devices
);
225 prev
= list_entry(gpio_devices
.prev
, struct gpio_device
, list
);
226 if (prev
->base
+ prev
->ngpio
<= gdev
->base
) {
227 /* add behind last entry */
228 list_add_tail(&gdev
->list
, &gpio_devices
);
232 list_for_each_entry_safe(prev
, next
, &gpio_devices
, list
) {
233 /* at the end of the list */
234 if (&next
->list
== &gpio_devices
)
237 /* add between prev and next */
238 if (prev
->base
+ prev
->ngpio
<= gdev
->base
239 && gdev
->base
+ gdev
->ngpio
<= next
->base
) {
240 list_add(&gdev
->list
, &prev
->list
);
245 dev_err(&gdev
->dev
, "GPIO integer space overlap, cannot add chip\n");
250 * Convert a GPIO name to its descriptor
252 static struct gpio_desc
*gpio_name_to_desc(const char * const name
)
254 struct gpio_device
*gdev
;
257 spin_lock_irqsave(&gpio_lock
, flags
);
259 list_for_each_entry(gdev
, &gpio_devices
, list
) {
262 for (i
= 0; i
!= gdev
->ngpio
; ++i
) {
263 struct gpio_desc
*desc
= &gdev
->descs
[i
];
265 if (!desc
->name
|| !name
)
268 if (!strcmp(desc
->name
, name
)) {
269 spin_unlock_irqrestore(&gpio_lock
, flags
);
275 spin_unlock_irqrestore(&gpio_lock
, flags
);
281 * Takes the names from gc->names and checks if they are all unique. If they
282 * are, they are assigned to their gpio descriptors.
284 * Warning if one of the names is already used for a different GPIO.
286 static int gpiochip_set_desc_names(struct gpio_chip
*gc
)
288 struct gpio_device
*gdev
= gc
->gpiodev
;
294 /* First check all names if they are unique */
295 for (i
= 0; i
!= gc
->ngpio
; ++i
) {
296 struct gpio_desc
*gpio
;
298 gpio
= gpio_name_to_desc(gc
->names
[i
]);
301 "Detected name collision for GPIO name '%s'\n",
305 /* Then add all names to the GPIO descriptors */
306 for (i
= 0; i
!= gc
->ngpio
; ++i
)
307 gdev
->descs
[i
].name
= gc
->names
[i
];
313 * gpio_ioctl() - ioctl handler for the GPIO chardev
315 static long gpio_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
317 struct gpio_device
*gdev
= filp
->private_data
;
318 struct gpio_chip
*chip
= gdev
->chip
;
319 int __user
*ip
= (int __user
*)arg
;
321 /* We fail any subsequent ioctl():s when the chip is gone */
325 /* Fill in the struct and pass to userspace */
326 if (cmd
== GPIO_GET_CHIPINFO_IOCTL
) {
327 struct gpiochip_info chipinfo
;
329 strncpy(chipinfo
.name
, dev_name(&gdev
->dev
),
330 sizeof(chipinfo
.name
));
331 chipinfo
.name
[sizeof(chipinfo
.name
)-1] = '\0';
332 strncpy(chipinfo
.label
, gdev
->label
,
333 sizeof(chipinfo
.label
));
334 chipinfo
.label
[sizeof(chipinfo
.label
)-1] = '\0';
335 chipinfo
.lines
= gdev
->ngpio
;
336 if (copy_to_user(ip
, &chipinfo
, sizeof(chipinfo
)))
339 } else if (cmd
== GPIO_GET_LINEINFO_IOCTL
) {
340 struct gpioline_info lineinfo
;
341 struct gpio_desc
*desc
;
343 if (copy_from_user(&lineinfo
, ip
, sizeof(lineinfo
)))
345 if (lineinfo
.line_offset
> gdev
->ngpio
)
348 desc
= &gdev
->descs
[lineinfo
.line_offset
];
350 strncpy(lineinfo
.name
, desc
->name
,
351 sizeof(lineinfo
.name
));
352 lineinfo
.name
[sizeof(lineinfo
.name
)-1] = '\0';
354 lineinfo
.name
[0] = '\0';
357 strncpy(lineinfo
.consumer
, desc
->label
,
358 sizeof(lineinfo
.consumer
));
359 lineinfo
.consumer
[sizeof(lineinfo
.consumer
)-1] = '\0';
361 lineinfo
.consumer
[0] = '\0';
365 * Userspace only need to know that the kernel is using
366 * this GPIO so it can't use it.
369 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) ||
370 test_bit(FLAG_IS_HOGGED
, &desc
->flags
) ||
371 test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
) ||
372 test_bit(FLAG_EXPORT
, &desc
->flags
) ||
373 test_bit(FLAG_SYSFS
, &desc
->flags
))
374 lineinfo
.flags
|= GPIOLINE_FLAG_KERNEL
;
375 if (test_bit(FLAG_IS_OUT
, &desc
->flags
))
376 lineinfo
.flags
|= GPIOLINE_FLAG_IS_OUT
;
377 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
378 lineinfo
.flags
|= GPIOLINE_FLAG_ACTIVE_LOW
;
379 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
380 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_DRAIN
;
381 if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
382 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_SOURCE
;
384 if (copy_to_user(ip
, &lineinfo
, sizeof(lineinfo
)))
392 * gpio_chrdev_open() - open the chardev for ioctl operations
393 * @inode: inode for this chardev
394 * @filp: file struct for storing private data
395 * Returns 0 on success
397 static int gpio_chrdev_open(struct inode
*inode
, struct file
*filp
)
399 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
400 struct gpio_device
, chrdev
);
402 /* Fail on open if the backing gpiochip is gone */
403 if (!gdev
|| !gdev
->chip
)
405 get_device(&gdev
->dev
);
406 filp
->private_data
= gdev
;
411 * gpio_chrdev_release() - close chardev after ioctl operations
412 * @inode: inode for this chardev
413 * @filp: file struct for storing private data
414 * Returns 0 on success
416 static int gpio_chrdev_release(struct inode
*inode
, struct file
*filp
)
418 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
419 struct gpio_device
, chrdev
);
423 put_device(&gdev
->dev
);
428 static const struct file_operations gpio_fileops
= {
429 .release
= gpio_chrdev_release
,
430 .open
= gpio_chrdev_open
,
431 .owner
= THIS_MODULE
,
432 .llseek
= noop_llseek
,
433 .unlocked_ioctl
= gpio_ioctl
,
434 .compat_ioctl
= gpio_ioctl
,
437 static void gpiodevice_release(struct device
*dev
)
439 struct gpio_device
*gdev
= dev_get_drvdata(dev
);
441 cdev_del(&gdev
->chrdev
);
442 list_del(&gdev
->list
);
443 ida_simple_remove(&gpio_ida
, gdev
->id
);
449 static int gpiochip_setup_dev(struct gpio_device
*gdev
)
453 cdev_init(&gdev
->chrdev
, &gpio_fileops
);
454 gdev
->chrdev
.owner
= THIS_MODULE
;
455 gdev
->chrdev
.kobj
.parent
= &gdev
->dev
.kobj
;
456 gdev
->dev
.devt
= MKDEV(MAJOR(gpio_devt
), gdev
->id
);
457 status
= cdev_add(&gdev
->chrdev
, gdev
->dev
.devt
, 1);
459 chip_warn(gdev
->chip
, "failed to add char device %d:%d\n",
460 MAJOR(gpio_devt
), gdev
->id
);
462 chip_dbg(gdev
->chip
, "added GPIO chardev (%d:%d)\n",
463 MAJOR(gpio_devt
), gdev
->id
);
464 status
= device_add(&gdev
->dev
);
466 goto err_remove_chardev
;
468 status
= gpiochip_sysfs_register(gdev
);
470 goto err_remove_device
;
472 /* From this point, the .release() function cleans up gpio_device */
473 gdev
->dev
.release
= gpiodevice_release
;
474 get_device(&gdev
->dev
);
475 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
476 __func__
, gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
477 dev_name(&gdev
->dev
), gdev
->chip
->label
? : "generic");
482 device_del(&gdev
->dev
);
484 cdev_del(&gdev
->chrdev
);
488 static void gpiochip_setup_devs(void)
490 struct gpio_device
*gdev
;
493 list_for_each_entry(gdev
, &gpio_devices
, list
) {
494 err
= gpiochip_setup_dev(gdev
);
496 pr_err("%s: Failed to initialize gpio device (%d)\n",
497 dev_name(&gdev
->dev
), err
);
502 * gpiochip_add_data() - register a gpio_chip
503 * @chip: the chip to register, with chip->base initialized
504 * Context: potentially before irqs will work
506 * Returns a negative errno if the chip can't be registered, such as
507 * because the chip->base is invalid or already associated with a
508 * different chip. Otherwise it returns zero as a success code.
510 * When gpiochip_add_data() is called very early during boot, so that GPIOs
511 * can be freely used, the chip->parent device must be registered before
512 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
513 * for GPIOs will fail rudely.
515 * gpiochip_add_data() must only be called after gpiolib initialization,
516 * ie after core_initcall().
518 * If chip->base is negative, this requests dynamic assignment of
519 * a range of valid GPIOs.
521 int gpiochip_add_data(struct gpio_chip
*chip
, void *data
)
526 int base
= chip
->base
;
527 struct gpio_device
*gdev
;
530 * First: allocate and populate the internal stat container, and
531 * set up the struct device.
533 gdev
= kzalloc(sizeof(*gdev
), GFP_KERNEL
);
536 gdev
->dev
.bus
= &gpio_bus_type
;
538 chip
->gpiodev
= gdev
;
540 gdev
->dev
.parent
= chip
->parent
;
541 gdev
->dev
.of_node
= chip
->parent
->of_node
;
543 #ifdef CONFIG_OF_GPIO
544 /* If the gpiochip has an assigned OF node this takes precedence */
546 gdev
->dev
.of_node
= chip
->of_node
;
549 gdev
->id
= ida_simple_get(&gpio_ida
, 0, 0, GFP_KERNEL
);
554 dev_set_name(&gdev
->dev
, "gpiochip%d", gdev
->id
);
555 device_initialize(&gdev
->dev
);
556 dev_set_drvdata(&gdev
->dev
, gdev
);
557 if (chip
->parent
&& chip
->parent
->driver
)
558 gdev
->owner
= chip
->parent
->driver
->owner
;
559 else if (chip
->owner
)
560 /* TODO: remove chip->owner */
561 gdev
->owner
= chip
->owner
;
563 gdev
->owner
= THIS_MODULE
;
565 gdev
->descs
= kcalloc(chip
->ngpio
, sizeof(gdev
->descs
[0]), GFP_KERNEL
);
571 if (chip
->ngpio
== 0) {
572 chip_err(chip
, "tried to insert a GPIO chip with zero lines\n");
578 gdev
->label
= kstrdup(chip
->label
, GFP_KERNEL
);
580 gdev
->label
= kstrdup("unknown", GFP_KERNEL
);
586 gdev
->ngpio
= chip
->ngpio
;
589 spin_lock_irqsave(&gpio_lock
, flags
);
592 * TODO: this allocates a Linux GPIO number base in the global
593 * GPIO numberspace for this chip. In the long run we want to
594 * get *rid* of this numberspace and use only descriptors, but
595 * it may be a pipe dream. It will not happen before we get rid
596 * of the sysfs interface anyways.
599 base
= gpiochip_find_base(chip
->ngpio
);
602 spin_unlock_irqrestore(&gpio_lock
, flags
);
606 * TODO: it should not be necessary to reflect the assigned
607 * base outside of the GPIO subsystem. Go over drivers and
608 * see if anyone makes use of this, else drop this and assign
615 status
= gpiodev_add_to_list(gdev
);
617 spin_unlock_irqrestore(&gpio_lock
, flags
);
621 for (i
= 0; i
< chip
->ngpio
; i
++) {
622 struct gpio_desc
*desc
= &gdev
->descs
[i
];
626 * REVISIT: most hardware initializes GPIOs as inputs
627 * (often with pullups enabled) so power usage is
628 * minimized. Linux code should set the gpio direction
629 * first thing; but until it does, and in case
630 * chip->get_direction is not set, we may expose the
631 * wrong direction in sysfs.
634 if (chip
->get_direction
) {
636 * If we have .get_direction, set up the initial
637 * direction flag from the hardware.
639 int dir
= chip
->get_direction(chip
, i
);
642 set_bit(FLAG_IS_OUT
, &desc
->flags
);
643 } else if (!chip
->direction_input
) {
645 * If the chip lacks the .direction_input callback
646 * we logically assume all lines are outputs.
648 set_bit(FLAG_IS_OUT
, &desc
->flags
);
652 spin_unlock_irqrestore(&gpio_lock
, flags
);
654 #ifdef CONFIG_PINCTRL
655 INIT_LIST_HEAD(&gdev
->pin_ranges
);
658 status
= gpiochip_set_desc_names(chip
);
660 goto err_remove_from_list
;
662 status
= of_gpiochip_add(chip
);
664 goto err_remove_chip
;
666 acpi_gpiochip_add(chip
);
669 * By first adding the chardev, and then adding the device,
670 * we get a device node entry in sysfs under
671 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
672 * coldplug of device nodes and other udev business.
673 * We can do this only if gpiolib has been initialized.
674 * Otherwise, defer until later.
676 if (gpiolib_initialized
) {
677 status
= gpiochip_setup_dev(gdev
);
679 goto err_remove_chip
;
684 acpi_gpiochip_remove(chip
);
685 gpiochip_free_hogs(chip
);
686 of_gpiochip_remove(chip
);
687 err_remove_from_list
:
688 spin_lock_irqsave(&gpio_lock
, flags
);
689 list_del(&gdev
->list
);
690 spin_unlock_irqrestore(&gpio_lock
, flags
);
696 ida_simple_remove(&gpio_ida
, gdev
->id
);
697 /* failures here can mean systems won't boot... */
698 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__
,
699 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
700 chip
->label
? : "generic");
704 EXPORT_SYMBOL_GPL(gpiochip_add_data
);
707 * gpiochip_get_data() - get per-subdriver data for the chip
709 void *gpiochip_get_data(struct gpio_chip
*chip
)
711 return chip
->gpiodev
->data
;
713 EXPORT_SYMBOL_GPL(gpiochip_get_data
);
716 * gpiochip_remove() - unregister a gpio_chip
717 * @chip: the chip to unregister
719 * A gpio_chip with any GPIOs still requested may not be removed.
721 void gpiochip_remove(struct gpio_chip
*chip
)
723 struct gpio_device
*gdev
= chip
->gpiodev
;
724 struct gpio_desc
*desc
;
727 bool requested
= false;
729 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
730 gpiochip_sysfs_unregister(gdev
);
731 /* Numb the device, cancelling all outstanding operations */
733 gpiochip_irqchip_remove(chip
);
734 acpi_gpiochip_remove(chip
);
735 gpiochip_remove_pin_ranges(chip
);
736 gpiochip_free_hogs(chip
);
737 of_gpiochip_remove(chip
);
739 * We accept no more calls into the driver from this point, so
740 * NULL the driver data pointer
744 spin_lock_irqsave(&gpio_lock
, flags
);
745 for (i
= 0; i
< gdev
->ngpio
; i
++) {
746 desc
= &gdev
->descs
[i
];
747 if (test_bit(FLAG_REQUESTED
, &desc
->flags
))
750 spin_unlock_irqrestore(&gpio_lock
, flags
);
754 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
757 * The gpiochip side puts its use of the device to rest here:
758 * if there are no userspace clients, the chardev and device will
759 * be removed, else it will be dangling until the last user is
762 put_device(&gdev
->dev
);
764 EXPORT_SYMBOL_GPL(gpiochip_remove
);
766 static void devm_gpio_chip_release(struct device
*dev
, void *res
)
768 struct gpio_chip
*chip
= *(struct gpio_chip
**)res
;
770 gpiochip_remove(chip
);
773 static int devm_gpio_chip_match(struct device
*dev
, void *res
, void *data
)
776 struct gpio_chip
**r
= res
;
787 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
788 * @dev: the device pointer on which irq_chip belongs to.
789 * @chip: the chip to register, with chip->base initialized
790 * Context: potentially before irqs will work
792 * Returns a negative errno if the chip can't be registered, such as
793 * because the chip->base is invalid or already associated with a
794 * different chip. Otherwise it returns zero as a success code.
796 * The gpio chip automatically be released when the device is unbound.
798 int devm_gpiochip_add_data(struct device
*dev
, struct gpio_chip
*chip
,
801 struct gpio_chip
**ptr
;
804 ptr
= devres_alloc(devm_gpio_chip_release
, sizeof(*ptr
),
809 ret
= gpiochip_add_data(chip
, data
);
816 devres_add(dev
, ptr
);
820 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data
);
823 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
824 * @dev: device for which which resource was allocated
825 * @chip: the chip to remove
827 * A gpio_chip with any GPIOs still requested may not be removed.
829 void devm_gpiochip_remove(struct device
*dev
, struct gpio_chip
*chip
)
833 ret
= devres_release(dev
, devm_gpio_chip_release
,
834 devm_gpio_chip_match
, chip
);
838 EXPORT_SYMBOL_GPL(devm_gpiochip_remove
);
841 * gpiochip_find() - iterator for locating a specific gpio_chip
842 * @data: data to pass to match function
843 * @callback: Callback function to check gpio_chip
845 * Similar to bus_find_device. It returns a reference to a gpio_chip as
846 * determined by a user supplied @match callback. The callback should return
847 * 0 if the device doesn't match and non-zero if it does. If the callback is
848 * non-zero, this function will return to the caller and not iterate over any
851 struct gpio_chip
*gpiochip_find(void *data
,
852 int (*match
)(struct gpio_chip
*chip
,
855 struct gpio_device
*gdev
;
856 struct gpio_chip
*chip
;
859 spin_lock_irqsave(&gpio_lock
, flags
);
860 list_for_each_entry(gdev
, &gpio_devices
, list
)
861 if (match(gdev
->chip
, data
))
865 if (&gdev
->list
== &gpio_devices
)
870 spin_unlock_irqrestore(&gpio_lock
, flags
);
874 EXPORT_SYMBOL_GPL(gpiochip_find
);
876 static int gpiochip_match_name(struct gpio_chip
*chip
, void *data
)
878 const char *name
= data
;
880 return !strcmp(chip
->label
, name
);
883 static struct gpio_chip
*find_chip_by_name(const char *name
)
885 return gpiochip_find((void *)name
, gpiochip_match_name
);
888 #ifdef CONFIG_GPIOLIB_IRQCHIP
891 * The following is irqchip helper code for gpiochips.
895 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
896 * @gpiochip: the gpiochip to set the irqchip chain to
897 * @irqchip: the irqchip to chain to the gpiochip
898 * @parent_irq: the irq number corresponding to the parent IRQ for this
900 * @parent_handler: the parent interrupt handler for the accumulated IRQ
901 * coming out of the gpiochip. If the interrupt is nested rather than
902 * cascaded, pass NULL in this handler argument
904 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
905 struct irq_chip
*irqchip
,
907 irq_flow_handler_t parent_handler
)
911 if (!gpiochip
->irqdomain
) {
912 chip_err(gpiochip
, "called %s before setting up irqchip\n",
917 if (parent_handler
) {
918 if (gpiochip
->can_sleep
) {
920 "you cannot have chained interrupts on a "
921 "chip that may sleep\n");
925 * The parent irqchip is already using the chip_data for this
926 * irqchip, so our callbacks simply use the handler_data.
928 irq_set_chained_handler_and_data(parent_irq
, parent_handler
,
931 gpiochip
->irq_parent
= parent_irq
;
934 /* Set the parent IRQ for all affected IRQs */
935 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
936 irq_set_parent(irq_find_mapping(gpiochip
->irqdomain
, offset
),
939 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip
);
942 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
943 * @d: the irqdomain used by this irqchip
944 * @irq: the global irq number used by this GPIO irqchip irq
945 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
947 * This function will set up the mapping for a certain IRQ line on a
948 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
949 * stored inside the gpiochip.
951 static int gpiochip_irq_map(struct irq_domain
*d
, unsigned int irq
,
952 irq_hw_number_t hwirq
)
954 struct gpio_chip
*chip
= d
->host_data
;
956 irq_set_chip_data(irq
, chip
);
958 * This lock class tells lockdep that GPIO irqs are in a different
959 * category than their parents, so it won't report false recursion.
961 irq_set_lockdep_class(irq
, chip
->lock_key
);
962 irq_set_chip_and_handler(irq
, chip
->irqchip
, chip
->irq_handler
);
963 /* Chips that can sleep need nested thread handlers */
964 if (chip
->can_sleep
&& !chip
->irq_not_threaded
)
965 irq_set_nested_thread(irq
, 1);
966 irq_set_noprobe(irq
);
969 * No set-up of the hardware will happen if IRQ_TYPE_NONE
970 * is passed as default type.
972 if (chip
->irq_default_type
!= IRQ_TYPE_NONE
)
973 irq_set_irq_type(irq
, chip
->irq_default_type
);
978 static void gpiochip_irq_unmap(struct irq_domain
*d
, unsigned int irq
)
980 struct gpio_chip
*chip
= d
->host_data
;
983 irq_set_nested_thread(irq
, 0);
984 irq_set_chip_and_handler(irq
, NULL
, NULL
);
985 irq_set_chip_data(irq
, NULL
);
988 static const struct irq_domain_ops gpiochip_domain_ops
= {
989 .map
= gpiochip_irq_map
,
990 .unmap
= gpiochip_irq_unmap
,
991 /* Virtually all GPIO irqchips are twocell:ed */
992 .xlate
= irq_domain_xlate_twocell
,
995 static int gpiochip_irq_reqres(struct irq_data
*d
)
997 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
999 if (!try_module_get(chip
->gpiodev
->owner
))
1002 if (gpiochip_lock_as_irq(chip
, d
->hwirq
)) {
1004 "unable to lock HW IRQ %lu for IRQ\n",
1006 module_put(chip
->gpiodev
->owner
);
1012 static void gpiochip_irq_relres(struct irq_data
*d
)
1014 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
1016 gpiochip_unlock_as_irq(chip
, d
->hwirq
);
1017 module_put(chip
->gpiodev
->owner
);
1020 static int gpiochip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
1022 return irq_find_mapping(chip
->irqdomain
, offset
);
1026 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1027 * @gpiochip: the gpiochip to remove the irqchip from
1029 * This is called only from gpiochip_remove()
1031 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
)
1033 unsigned int offset
;
1035 acpi_gpiochip_free_interrupts(gpiochip
);
1037 if (gpiochip
->irq_parent
) {
1038 irq_set_chained_handler(gpiochip
->irq_parent
, NULL
);
1039 irq_set_handler_data(gpiochip
->irq_parent
, NULL
);
1042 /* Remove all IRQ mappings and delete the domain */
1043 if (gpiochip
->irqdomain
) {
1044 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
1045 irq_dispose_mapping(
1046 irq_find_mapping(gpiochip
->irqdomain
, offset
));
1047 irq_domain_remove(gpiochip
->irqdomain
);
1050 if (gpiochip
->irqchip
) {
1051 gpiochip
->irqchip
->irq_request_resources
= NULL
;
1052 gpiochip
->irqchip
->irq_release_resources
= NULL
;
1053 gpiochip
->irqchip
= NULL
;
1058 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1059 * @gpiochip: the gpiochip to add the irqchip to
1060 * @irqchip: the irqchip to add to the gpiochip
1061 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1062 * allocate gpiochip irqs from
1063 * @handler: the irq handler to use (often a predefined irq core function)
1064 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1065 * to have the core avoid setting up any default type in the hardware.
1066 * @lock_key: lockdep class
1068 * This function closely associates a certain irqchip with a certain
1069 * gpiochip, providing an irq domain to translate the local IRQs to
1070 * global irqs in the gpiolib core, and making sure that the gpiochip
1071 * is passed as chip data to all related functions. Driver callbacks
1072 * need to use gpiochip_get_data() to get their local state containers back
1073 * from the gpiochip passed as chip data. An irqdomain will be stored
1074 * in the gpiochip that shall be used by the driver to handle IRQ number
1075 * translation. The gpiochip will need to be initialized and registered
1076 * before calling this function.
1078 * This function will handle two cell:ed simple IRQs and assumes all
1079 * the pins on the gpiochip can generate a unique IRQ. Everything else
1080 * need to be open coded.
1082 int _gpiochip_irqchip_add(struct gpio_chip
*gpiochip
,
1083 struct irq_chip
*irqchip
,
1084 unsigned int first_irq
,
1085 irq_flow_handler_t handler
,
1087 struct lock_class_key
*lock_key
)
1089 struct device_node
*of_node
;
1090 unsigned int offset
;
1091 unsigned irq_base
= 0;
1093 if (!gpiochip
|| !irqchip
)
1096 if (!gpiochip
->parent
) {
1097 pr_err("missing gpiochip .dev parent pointer\n");
1100 of_node
= gpiochip
->parent
->of_node
;
1101 #ifdef CONFIG_OF_GPIO
1103 * If the gpiochip has an assigned OF node this takes precedence
1104 * FIXME: get rid of this and use gpiochip->parent->of_node
1107 if (gpiochip
->of_node
)
1108 of_node
= gpiochip
->of_node
;
1110 gpiochip
->irqchip
= irqchip
;
1111 gpiochip
->irq_handler
= handler
;
1112 gpiochip
->irq_default_type
= type
;
1113 gpiochip
->to_irq
= gpiochip_to_irq
;
1114 gpiochip
->lock_key
= lock_key
;
1115 gpiochip
->irqdomain
= irq_domain_add_simple(of_node
,
1116 gpiochip
->ngpio
, first_irq
,
1117 &gpiochip_domain_ops
, gpiochip
);
1118 if (!gpiochip
->irqdomain
) {
1119 gpiochip
->irqchip
= NULL
;
1124 * It is possible for a driver to override this, but only if the
1125 * alternative functions are both implemented.
1127 if (!irqchip
->irq_request_resources
&&
1128 !irqchip
->irq_release_resources
) {
1129 irqchip
->irq_request_resources
= gpiochip_irq_reqres
;
1130 irqchip
->irq_release_resources
= gpiochip_irq_relres
;
1134 * Prepare the mapping since the irqchip shall be orthogonal to
1135 * any gpiochip calls. If the first_irq was zero, this is
1136 * necessary to allocate descriptors for all IRQs.
1138 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1139 irq_base
= irq_create_mapping(gpiochip
->irqdomain
, offset
);
1142 * Store the base into the gpiochip to be used when
1143 * unmapping the irqs.
1145 gpiochip
->irq_base
= irq_base
;
1148 acpi_gpiochip_request_interrupts(gpiochip
);
1152 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add
);
1154 #else /* CONFIG_GPIOLIB_IRQCHIP */
1156 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
) {}
1158 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1161 * gpiochip_generic_request() - request the gpio function for a pin
1162 * @chip: the gpiochip owning the GPIO
1163 * @offset: the offset of the GPIO to request for GPIO function
1165 int gpiochip_generic_request(struct gpio_chip
*chip
, unsigned offset
)
1167 return pinctrl_request_gpio(chip
->gpiodev
->base
+ offset
);
1169 EXPORT_SYMBOL_GPL(gpiochip_generic_request
);
1172 * gpiochip_generic_free() - free the gpio function from a pin
1173 * @chip: the gpiochip to request the gpio function for
1174 * @offset: the offset of the GPIO to free from GPIO function
1176 void gpiochip_generic_free(struct gpio_chip
*chip
, unsigned offset
)
1178 pinctrl_free_gpio(chip
->gpiodev
->base
+ offset
);
1180 EXPORT_SYMBOL_GPL(gpiochip_generic_free
);
1182 #ifdef CONFIG_PINCTRL
1185 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1186 * @chip: the gpiochip to add the range for
1187 * @pctldev: the pin controller to map to
1188 * @gpio_offset: the start offset in the current gpio_chip number space
1189 * @pin_group: name of the pin group inside the pin controller
1191 int gpiochip_add_pingroup_range(struct gpio_chip
*chip
,
1192 struct pinctrl_dev
*pctldev
,
1193 unsigned int gpio_offset
, const char *pin_group
)
1195 struct gpio_pin_range
*pin_range
;
1196 struct gpio_device
*gdev
= chip
->gpiodev
;
1199 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1201 chip_err(chip
, "failed to allocate pin ranges\n");
1205 /* Use local offset as range ID */
1206 pin_range
->range
.id
= gpio_offset
;
1207 pin_range
->range
.gc
= chip
;
1208 pin_range
->range
.name
= chip
->label
;
1209 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1210 pin_range
->pctldev
= pctldev
;
1212 ret
= pinctrl_get_group_pins(pctldev
, pin_group
,
1213 &pin_range
->range
.pins
,
1214 &pin_range
->range
.npins
);
1220 pinctrl_add_gpio_range(pctldev
, &pin_range
->range
);
1222 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1223 gpio_offset
, gpio_offset
+ pin_range
->range
.npins
- 1,
1224 pinctrl_dev_get_devname(pctldev
), pin_group
);
1226 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1230 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range
);
1233 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1234 * @chip: the gpiochip to add the range for
1235 * @pinctrl_name: the dev_name() of the pin controller to map to
1236 * @gpio_offset: the start offset in the current gpio_chip number space
1237 * @pin_offset: the start offset in the pin controller number space
1238 * @npins: the number of pins from the offset of each pin space (GPIO and
1239 * pin controller) to accumulate in this range
1241 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
1242 unsigned int gpio_offset
, unsigned int pin_offset
,
1245 struct gpio_pin_range
*pin_range
;
1246 struct gpio_device
*gdev
= chip
->gpiodev
;
1249 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1251 chip_err(chip
, "failed to allocate pin ranges\n");
1255 /* Use local offset as range ID */
1256 pin_range
->range
.id
= gpio_offset
;
1257 pin_range
->range
.gc
= chip
;
1258 pin_range
->range
.name
= chip
->label
;
1259 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1260 pin_range
->range
.pin_base
= pin_offset
;
1261 pin_range
->range
.npins
= npins
;
1262 pin_range
->pctldev
= pinctrl_find_and_add_gpio_range(pinctl_name
,
1264 if (IS_ERR(pin_range
->pctldev
)) {
1265 ret
= PTR_ERR(pin_range
->pctldev
);
1266 chip_err(chip
, "could not create pin range\n");
1270 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1271 gpio_offset
, gpio_offset
+ npins
- 1,
1273 pin_offset
, pin_offset
+ npins
- 1);
1275 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1279 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range
);
1282 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1283 * @chip: the chip to remove all the mappings for
1285 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
1287 struct gpio_pin_range
*pin_range
, *tmp
;
1288 struct gpio_device
*gdev
= chip
->gpiodev
;
1290 list_for_each_entry_safe(pin_range
, tmp
, &gdev
->pin_ranges
, node
) {
1291 list_del(&pin_range
->node
);
1292 pinctrl_remove_gpio_range(pin_range
->pctldev
,
1297 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges
);
1299 #endif /* CONFIG_PINCTRL */
1301 /* These "optional" allocation calls help prevent drivers from stomping
1302 * on each other, and help provide better diagnostics in debugfs.
1303 * They're called even less than the "set direction" calls.
1305 static int __gpiod_request(struct gpio_desc
*desc
, const char *label
)
1307 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1309 unsigned long flags
;
1311 spin_lock_irqsave(&gpio_lock
, flags
);
1313 /* NOTE: gpio_request() can be called in early boot,
1314 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1317 if (test_and_set_bit(FLAG_REQUESTED
, &desc
->flags
) == 0) {
1318 desc_set_label(desc
, label
? : "?");
1325 if (chip
->request
) {
1326 /* chip->request may sleep */
1327 spin_unlock_irqrestore(&gpio_lock
, flags
);
1328 status
= chip
->request(chip
, gpio_chip_hwgpio(desc
));
1329 spin_lock_irqsave(&gpio_lock
, flags
);
1332 desc_set_label(desc
, NULL
);
1333 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1337 if (chip
->get_direction
) {
1338 /* chip->get_direction may sleep */
1339 spin_unlock_irqrestore(&gpio_lock
, flags
);
1340 gpiod_get_direction(desc
);
1341 spin_lock_irqsave(&gpio_lock
, flags
);
1345 /* Clear flags that might have been set by the caller before
1346 * requesting the GPIO.
1348 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1349 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1350 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1352 spin_unlock_irqrestore(&gpio_lock
, flags
);
1357 * This descriptor validation needs to be inserted verbatim into each
1358 * function taking a descriptor, so we need to use a preprocessor
1359 * macro to avoid endless duplication.
1361 #define VALIDATE_DESC(desc) do { \
1362 if (!desc || !desc->gdev) { \
1363 pr_warn("%s: invalid GPIO\n", __func__); \
1366 if ( !desc->gdev->chip ) { \
1367 dev_warn(&desc->gdev->dev, \
1368 "%s: backing chip is gone\n", __func__); \
1372 #define VALIDATE_DESC_VOID(desc) do { \
1373 if (!desc || !desc->gdev) { \
1374 pr_warn("%s: invalid GPIO\n", __func__); \
1377 if (!desc->gdev->chip) { \
1378 dev_warn(&desc->gdev->dev, \
1379 "%s: backing chip is gone\n", __func__); \
1384 int gpiod_request(struct gpio_desc
*desc
, const char *label
)
1386 int status
= -EPROBE_DEFER
;
1387 struct gpio_device
*gdev
;
1389 VALIDATE_DESC(desc
);
1392 if (try_module_get(gdev
->owner
)) {
1393 status
= __gpiod_request(desc
, label
);
1395 module_put(gdev
->owner
);
1397 get_device(&gdev
->dev
);
1401 gpiod_dbg(desc
, "%s: status %d\n", __func__
, status
);
1406 static bool __gpiod_free(struct gpio_desc
*desc
)
1409 unsigned long flags
;
1410 struct gpio_chip
*chip
;
1414 gpiod_unexport(desc
);
1416 spin_lock_irqsave(&gpio_lock
, flags
);
1418 chip
= desc
->gdev
->chip
;
1419 if (chip
&& test_bit(FLAG_REQUESTED
, &desc
->flags
)) {
1421 spin_unlock_irqrestore(&gpio_lock
, flags
);
1422 might_sleep_if(chip
->can_sleep
);
1423 chip
->free(chip
, gpio_chip_hwgpio(desc
));
1424 spin_lock_irqsave(&gpio_lock
, flags
);
1426 desc_set_label(desc
, NULL
);
1427 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1428 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1429 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1430 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1431 clear_bit(FLAG_IS_HOGGED
, &desc
->flags
);
1435 spin_unlock_irqrestore(&gpio_lock
, flags
);
1439 void gpiod_free(struct gpio_desc
*desc
)
1441 if (desc
&& desc
->gdev
&& __gpiod_free(desc
)) {
1442 module_put(desc
->gdev
->owner
);
1443 put_device(&desc
->gdev
->dev
);
1445 WARN_ON(extra_checks
);
1450 * gpiochip_is_requested - return string iff signal was requested
1451 * @chip: controller managing the signal
1452 * @offset: of signal within controller's 0..(ngpio - 1) range
1454 * Returns NULL if the GPIO is not currently requested, else a string.
1455 * The string returned is the label passed to gpio_request(); if none has been
1456 * passed it is a meaningless, non-NULL constant.
1458 * This function is for use by GPIO controller drivers. The label can
1459 * help with diagnostics, and knowing that the signal is used as a GPIO
1460 * can help avoid accidentally multiplexing it to another controller.
1462 const char *gpiochip_is_requested(struct gpio_chip
*chip
, unsigned offset
)
1464 struct gpio_desc
*desc
;
1466 if (offset
>= chip
->ngpio
)
1469 desc
= &chip
->gpiodev
->descs
[offset
];
1471 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) == 0)
1475 EXPORT_SYMBOL_GPL(gpiochip_is_requested
);
1478 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1479 * @desc: GPIO descriptor to request
1480 * @label: label for the GPIO
1482 * Function allows GPIO chip drivers to request and use their own GPIO
1483 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1484 * function will not increase reference count of the GPIO chip module. This
1485 * allows the GPIO chip module to be unloaded as needed (we assume that the
1486 * GPIO chip driver handles freeing the GPIOs it has requested).
1488 struct gpio_desc
*gpiochip_request_own_desc(struct gpio_chip
*chip
, u16 hwnum
,
1491 struct gpio_desc
*desc
= gpiochip_get_desc(chip
, hwnum
);
1495 chip_err(chip
, "failed to get GPIO descriptor\n");
1499 err
= __gpiod_request(desc
, label
);
1501 return ERR_PTR(err
);
1505 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc
);
1508 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1509 * @desc: GPIO descriptor to free
1511 * Function frees the given GPIO requested previously with
1512 * gpiochip_request_own_desc().
1514 void gpiochip_free_own_desc(struct gpio_desc
*desc
)
1519 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc
);
1522 * Drivers MUST set GPIO direction before making get/set calls. In
1523 * some cases this is done in early boot, before IRQs are enabled.
1525 * As a rule these aren't called more than once (except for drivers
1526 * using the open-drain emulation idiom) so these are natural places
1527 * to accumulate extra debugging checks. Note that we can't (yet)
1528 * rely on gpio_request() having been called beforehand.
1532 * gpiod_direction_input - set the GPIO direction to input
1533 * @desc: GPIO to set to input
1535 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1536 * be called safely on it.
1538 * Return 0 in case of success, else an error code.
1540 int gpiod_direction_input(struct gpio_desc
*desc
)
1542 struct gpio_chip
*chip
;
1543 int status
= -EINVAL
;
1545 VALIDATE_DESC(desc
);
1546 chip
= desc
->gdev
->chip
;
1548 if (!chip
->get
|| !chip
->direction_input
) {
1550 "%s: missing get() or direction_input() operations\n",
1555 status
= chip
->direction_input(chip
, gpio_chip_hwgpio(desc
));
1557 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1559 trace_gpio_direction(desc_to_gpio(desc
), 1, status
);
1563 EXPORT_SYMBOL_GPL(gpiod_direction_input
);
1565 static int _gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1567 struct gpio_chip
*gc
= desc
->gdev
->chip
;
1570 /* GPIOs used for IRQs shall not be set as output */
1571 if (test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
)) {
1573 "%s: tried to set a GPIO tied to an IRQ as output\n",
1578 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
1579 /* First see if we can enable open drain in hardware */
1580 if (gc
->set_single_ended
) {
1581 ret
= gc
->set_single_ended(gc
, gpio_chip_hwgpio(desc
),
1582 LINE_MODE_OPEN_DRAIN
);
1584 goto set_output_value
;
1586 /* Emulate open drain by not actively driving the line high */
1588 return gpiod_direction_input(desc
);
1590 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
1591 if (gc
->set_single_ended
) {
1592 ret
= gc
->set_single_ended(gc
, gpio_chip_hwgpio(desc
),
1593 LINE_MODE_OPEN_SOURCE
);
1595 goto set_output_value
;
1597 /* Emulate open source by not actively driving the line low */
1599 return gpiod_direction_input(desc
);
1601 /* Make sure to disable open drain/source hardware, if any */
1602 if (gc
->set_single_ended
)
1603 gc
->set_single_ended(gc
,
1604 gpio_chip_hwgpio(desc
),
1605 LINE_MODE_PUSH_PULL
);
1609 if (!gc
->set
|| !gc
->direction_output
) {
1611 "%s: missing set() or direction_output() operations\n",
1616 ret
= gc
->direction_output(gc
, gpio_chip_hwgpio(desc
), value
);
1618 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1619 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1620 trace_gpio_direction(desc_to_gpio(desc
), 0, ret
);
1625 * gpiod_direction_output_raw - set the GPIO direction to output
1626 * @desc: GPIO to set to output
1627 * @value: initial output value of the GPIO
1629 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1630 * be called safely on it. The initial value of the output must be specified
1631 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1633 * Return 0 in case of success, else an error code.
1635 int gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1637 VALIDATE_DESC(desc
);
1638 return _gpiod_direction_output_raw(desc
, value
);
1640 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw
);
1643 * gpiod_direction_output - set the GPIO direction to output
1644 * @desc: GPIO to set to output
1645 * @value: initial output value of the GPIO
1647 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1648 * be called safely on it. The initial value of the output must be specified
1649 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1652 * Return 0 in case of success, else an error code.
1654 int gpiod_direction_output(struct gpio_desc
*desc
, int value
)
1656 VALIDATE_DESC(desc
);
1657 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1659 return _gpiod_direction_output_raw(desc
, value
);
1661 EXPORT_SYMBOL_GPL(gpiod_direction_output
);
1664 * gpiod_set_debounce - sets @debounce time for a @gpio
1665 * @gpio: the gpio to set debounce time
1666 * @debounce: debounce time is microseconds
1668 * returns -ENOTSUPP if the controller does not support setting
1671 int gpiod_set_debounce(struct gpio_desc
*desc
, unsigned debounce
)
1673 struct gpio_chip
*chip
;
1675 VALIDATE_DESC(desc
);
1676 chip
= desc
->gdev
->chip
;
1677 if (!chip
->set
|| !chip
->set_debounce
) {
1679 "%s: missing set() or set_debounce() operations\n",
1684 return chip
->set_debounce(chip
, gpio_chip_hwgpio(desc
), debounce
);
1686 EXPORT_SYMBOL_GPL(gpiod_set_debounce
);
1689 * gpiod_is_active_low - test whether a GPIO is active-low or not
1690 * @desc: the gpio descriptor to test
1692 * Returns 1 if the GPIO is active-low, 0 otherwise.
1694 int gpiod_is_active_low(const struct gpio_desc
*desc
)
1696 VALIDATE_DESC(desc
);
1697 return test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1699 EXPORT_SYMBOL_GPL(gpiod_is_active_low
);
1701 /* I/O calls are only valid after configuration completed; the relevant
1702 * "is this a valid GPIO" error checks should already have been done.
1704 * "Get" operations are often inlinable as reading a pin value register,
1705 * and masking the relevant bit in that register.
1707 * When "set" operations are inlinable, they involve writing that mask to
1708 * one register to set a low value, or a different register to set it high.
1709 * Otherwise locking is needed, so there may be little value to inlining.
1711 *------------------------------------------------------------------------
1713 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1714 * have requested the GPIO. That can include implicit requesting by
1715 * a direction setting call. Marking a gpio as requested locks its chip
1716 * in memory, guaranteeing that these table lookups need no more locking
1717 * and that gpiochip_remove() will fail.
1719 * REVISIT when debugging, consider adding some instrumentation to ensure
1720 * that the GPIO was actually requested.
1723 static int _gpiod_get_raw_value(const struct gpio_desc
*desc
)
1725 struct gpio_chip
*chip
;
1729 chip
= desc
->gdev
->chip
;
1730 offset
= gpio_chip_hwgpio(desc
);
1731 value
= chip
->get
? chip
->get(chip
, offset
) : -EIO
;
1732 value
= value
< 0 ? value
: !!value
;
1733 trace_gpio_value(desc_to_gpio(desc
), 1, value
);
1738 * gpiod_get_raw_value() - return a gpio's raw value
1739 * @desc: gpio whose value will be returned
1741 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1742 * its ACTIVE_LOW status, or negative errno on failure.
1744 * This function should be called from contexts where we cannot sleep, and will
1745 * complain if the GPIO chip functions potentially sleep.
1747 int gpiod_get_raw_value(const struct gpio_desc
*desc
)
1749 VALIDATE_DESC(desc
);
1750 /* Should be using gpio_get_value_cansleep() */
1751 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1752 return _gpiod_get_raw_value(desc
);
1754 EXPORT_SYMBOL_GPL(gpiod_get_raw_value
);
1757 * gpiod_get_value() - return a gpio's value
1758 * @desc: gpio whose value will be returned
1760 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1761 * account, or negative errno on failure.
1763 * This function should be called from contexts where we cannot sleep, and will
1764 * complain if the GPIO chip functions potentially sleep.
1766 int gpiod_get_value(const struct gpio_desc
*desc
)
1770 VALIDATE_DESC(desc
);
1771 /* Should be using gpio_get_value_cansleep() */
1772 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1774 value
= _gpiod_get_raw_value(desc
);
1778 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1783 EXPORT_SYMBOL_GPL(gpiod_get_value
);
1786 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1787 * @desc: gpio descriptor whose state need to be set.
1788 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1790 static void _gpio_set_open_drain_value(struct gpio_desc
*desc
, bool value
)
1793 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1794 int offset
= gpio_chip_hwgpio(desc
);
1797 err
= chip
->direction_input(chip
, offset
);
1799 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1801 err
= chip
->direction_output(chip
, offset
, 0);
1803 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1805 trace_gpio_direction(desc_to_gpio(desc
), value
, err
);
1808 "%s: Error in set_value for open drain err %d\n",
1813 * _gpio_set_open_source_value() - Set the open source gpio's value.
1814 * @desc: gpio descriptor whose state need to be set.
1815 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1817 static void _gpio_set_open_source_value(struct gpio_desc
*desc
, bool value
)
1820 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1821 int offset
= gpio_chip_hwgpio(desc
);
1824 err
= chip
->direction_output(chip
, offset
, 1);
1826 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1828 err
= chip
->direction_input(chip
, offset
);
1830 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1832 trace_gpio_direction(desc_to_gpio(desc
), !value
, err
);
1835 "%s: Error in set_value for open source err %d\n",
1839 static void _gpiod_set_raw_value(struct gpio_desc
*desc
, bool value
)
1841 struct gpio_chip
*chip
;
1843 chip
= desc
->gdev
->chip
;
1844 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1845 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
1846 _gpio_set_open_drain_value(desc
, value
);
1847 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
1848 _gpio_set_open_source_value(desc
, value
);
1850 chip
->set(chip
, gpio_chip_hwgpio(desc
), value
);
1854 * set multiple outputs on the same chip;
1855 * use the chip's set_multiple function if available;
1856 * otherwise set the outputs sequentially;
1857 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1858 * defines which outputs are to be changed
1859 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1860 * defines the values the outputs specified by mask are to be set to
1862 static void gpio_chip_set_multiple(struct gpio_chip
*chip
,
1863 unsigned long *mask
, unsigned long *bits
)
1865 if (chip
->set_multiple
) {
1866 chip
->set_multiple(chip
, mask
, bits
);
1869 for (i
= 0; i
< chip
->ngpio
; i
++) {
1870 if (mask
[BIT_WORD(i
)] == 0) {
1871 /* no more set bits in this mask word;
1872 * skip ahead to the next word */
1873 i
= (BIT_WORD(i
) + 1) * BITS_PER_LONG
- 1;
1876 /* set outputs if the corresponding mask bit is set */
1877 if (__test_and_clear_bit(i
, mask
))
1878 chip
->set(chip
, i
, test_bit(i
, bits
));
1883 void gpiod_set_array_value_complex(bool raw
, bool can_sleep
,
1884 unsigned int array_size
,
1885 struct gpio_desc
**desc_array
,
1890 while (i
< array_size
) {
1891 struct gpio_chip
*chip
= desc_array
[i
]->gdev
->chip
;
1892 unsigned long mask
[BITS_TO_LONGS(chip
->ngpio
)];
1893 unsigned long bits
[BITS_TO_LONGS(chip
->ngpio
)];
1897 WARN_ON(chip
->can_sleep
);
1899 memset(mask
, 0, sizeof(mask
));
1901 struct gpio_desc
*desc
= desc_array
[i
];
1902 int hwgpio
= gpio_chip_hwgpio(desc
);
1903 int value
= value_array
[i
];
1905 if (!raw
&& test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1907 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1909 * collect all normal outputs belonging to the same chip
1910 * open drain and open source outputs are set individually
1912 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
1913 _gpio_set_open_drain_value(desc
, value
);
1914 } else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
1915 _gpio_set_open_source_value(desc
, value
);
1917 __set_bit(hwgpio
, mask
);
1919 __set_bit(hwgpio
, bits
);
1921 __clear_bit(hwgpio
, bits
);
1925 } while ((i
< array_size
) &&
1926 (desc_array
[i
]->gdev
->chip
== chip
));
1927 /* push collected bits to outputs */
1929 gpio_chip_set_multiple(chip
, mask
, bits
);
1934 * gpiod_set_raw_value() - assign a gpio's raw value
1935 * @desc: gpio whose value will be assigned
1936 * @value: value to assign
1938 * Set the raw value of the GPIO, i.e. the value of its physical line without
1939 * regard for its ACTIVE_LOW status.
1941 * This function should be called from contexts where we cannot sleep, and will
1942 * complain if the GPIO chip functions potentially sleep.
1944 void gpiod_set_raw_value(struct gpio_desc
*desc
, int value
)
1946 VALIDATE_DESC_VOID(desc
);
1947 /* Should be using gpiod_set_value_cansleep() */
1948 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1949 _gpiod_set_raw_value(desc
, value
);
1951 EXPORT_SYMBOL_GPL(gpiod_set_raw_value
);
1954 * gpiod_set_value() - assign a gpio's value
1955 * @desc: gpio whose value will be assigned
1956 * @value: value to assign
1958 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1961 * This function should be called from contexts where we cannot sleep, and will
1962 * complain if the GPIO chip functions potentially sleep.
1964 void gpiod_set_value(struct gpio_desc
*desc
, int value
)
1966 VALIDATE_DESC_VOID(desc
);
1967 /* Should be using gpiod_set_value_cansleep() */
1968 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1969 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1971 _gpiod_set_raw_value(desc
, value
);
1973 EXPORT_SYMBOL_GPL(gpiod_set_value
);
1976 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1977 * @array_size: number of elements in the descriptor / value arrays
1978 * @desc_array: array of GPIO descriptors whose values will be assigned
1979 * @value_array: array of values to assign
1981 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1982 * without regard for their ACTIVE_LOW status.
1984 * This function should be called from contexts where we cannot sleep, and will
1985 * complain if the GPIO chip functions potentially sleep.
1987 void gpiod_set_raw_array_value(unsigned int array_size
,
1988 struct gpio_desc
**desc_array
, int *value_array
)
1992 gpiod_set_array_value_complex(true, false, array_size
, desc_array
,
1995 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value
);
1998 * gpiod_set_array_value() - assign values to an array of GPIOs
1999 * @array_size: number of elements in the descriptor / value arrays
2000 * @desc_array: array of GPIO descriptors whose values will be assigned
2001 * @value_array: array of values to assign
2003 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2006 * This function should be called from contexts where we cannot sleep, and will
2007 * complain if the GPIO chip functions potentially sleep.
2009 void gpiod_set_array_value(unsigned int array_size
,
2010 struct gpio_desc
**desc_array
, int *value_array
)
2014 gpiod_set_array_value_complex(false, false, array_size
, desc_array
,
2017 EXPORT_SYMBOL_GPL(gpiod_set_array_value
);
2020 * gpiod_cansleep() - report whether gpio value access may sleep
2021 * @desc: gpio to check
2024 int gpiod_cansleep(const struct gpio_desc
*desc
)
2026 VALIDATE_DESC(desc
);
2027 return desc
->gdev
->chip
->can_sleep
;
2029 EXPORT_SYMBOL_GPL(gpiod_cansleep
);
2032 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2033 * @desc: gpio whose IRQ will be returned (already requested)
2035 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2038 int gpiod_to_irq(const struct gpio_desc
*desc
)
2040 struct gpio_chip
*chip
;
2043 VALIDATE_DESC(desc
);
2044 chip
= desc
->gdev
->chip
;
2045 offset
= gpio_chip_hwgpio(desc
);
2047 int retirq
= chip
->to_irq(chip
, offset
);
2049 /* Zero means NO_IRQ */
2057 EXPORT_SYMBOL_GPL(gpiod_to_irq
);
2060 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2061 * @chip: the chip the GPIO to lock belongs to
2062 * @offset: the offset of the GPIO to lock as IRQ
2064 * This is used directly by GPIO drivers that want to lock down
2065 * a certain GPIO line to be used for IRQs.
2067 int gpiochip_lock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2069 if (offset
>= chip
->ngpio
)
2072 if (test_bit(FLAG_IS_OUT
, &chip
->gpiodev
->descs
[offset
].flags
)) {
2074 "%s: tried to flag a GPIO set as output for IRQ\n",
2079 set_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2082 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq
);
2085 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2086 * @chip: the chip the GPIO to lock belongs to
2087 * @offset: the offset of the GPIO to lock as IRQ
2089 * This is used directly by GPIO drivers that want to indicate
2090 * that a certain GPIO is no longer used exclusively for IRQ.
2092 void gpiochip_unlock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
2094 if (offset
>= chip
->ngpio
)
2097 clear_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2099 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq
);
2101 bool gpiochip_line_is_irq(struct gpio_chip
*chip
, unsigned int offset
)
2103 if (offset
>= chip
->ngpio
)
2106 return test_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
2108 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq
);
2110 bool gpiochip_line_is_open_drain(struct gpio_chip
*chip
, unsigned int offset
)
2112 if (offset
>= chip
->ngpio
)
2115 return test_bit(FLAG_OPEN_DRAIN
, &chip
->gpiodev
->descs
[offset
].flags
);
2117 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain
);
2119 bool gpiochip_line_is_open_source(struct gpio_chip
*chip
, unsigned int offset
)
2121 if (offset
>= chip
->ngpio
)
2124 return test_bit(FLAG_OPEN_SOURCE
, &chip
->gpiodev
->descs
[offset
].flags
);
2126 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source
);
2129 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2130 * @desc: gpio whose value will be returned
2132 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2133 * its ACTIVE_LOW status, or negative errno on failure.
2135 * This function is to be called from contexts that can sleep.
2137 int gpiod_get_raw_value_cansleep(const struct gpio_desc
*desc
)
2139 might_sleep_if(extra_checks
);
2140 VALIDATE_DESC(desc
);
2141 return _gpiod_get_raw_value(desc
);
2143 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep
);
2146 * gpiod_get_value_cansleep() - return a gpio's value
2147 * @desc: gpio whose value will be returned
2149 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2150 * account, or negative errno on failure.
2152 * This function is to be called from contexts that can sleep.
2154 int gpiod_get_value_cansleep(const struct gpio_desc
*desc
)
2158 might_sleep_if(extra_checks
);
2159 VALIDATE_DESC(desc
);
2160 value
= _gpiod_get_raw_value(desc
);
2164 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2169 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep
);
2172 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2173 * @desc: gpio whose value will be assigned
2174 * @value: value to assign
2176 * Set the raw value of the GPIO, i.e. the value of its physical line without
2177 * regard for its ACTIVE_LOW status.
2179 * This function is to be called from contexts that can sleep.
2181 void gpiod_set_raw_value_cansleep(struct gpio_desc
*desc
, int value
)
2183 might_sleep_if(extra_checks
);
2184 VALIDATE_DESC_VOID(desc
);
2185 _gpiod_set_raw_value(desc
, value
);
2187 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep
);
2190 * gpiod_set_value_cansleep() - assign a gpio's value
2191 * @desc: gpio whose value will be assigned
2192 * @value: value to assign
2194 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2197 * This function is to be called from contexts that can sleep.
2199 void gpiod_set_value_cansleep(struct gpio_desc
*desc
, int value
)
2201 might_sleep_if(extra_checks
);
2202 VALIDATE_DESC_VOID(desc
);
2203 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2205 _gpiod_set_raw_value(desc
, value
);
2207 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep
);
2210 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2211 * @array_size: number of elements in the descriptor / value arrays
2212 * @desc_array: array of GPIO descriptors whose values will be assigned
2213 * @value_array: array of values to assign
2215 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2216 * without regard for their ACTIVE_LOW status.
2218 * This function is to be called from contexts that can sleep.
2220 void gpiod_set_raw_array_value_cansleep(unsigned int array_size
,
2221 struct gpio_desc
**desc_array
,
2224 might_sleep_if(extra_checks
);
2227 gpiod_set_array_value_complex(true, true, array_size
, desc_array
,
2230 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep
);
2233 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2234 * @array_size: number of elements in the descriptor / value arrays
2235 * @desc_array: array of GPIO descriptors whose values will be assigned
2236 * @value_array: array of values to assign
2238 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2241 * This function is to be called from contexts that can sleep.
2243 void gpiod_set_array_value_cansleep(unsigned int array_size
,
2244 struct gpio_desc
**desc_array
,
2247 might_sleep_if(extra_checks
);
2250 gpiod_set_array_value_complex(false, true, array_size
, desc_array
,
2253 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep
);
2256 * gpiod_add_lookup_table() - register GPIO device consumers
2257 * @table: table of consumers to register
2259 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
)
2261 mutex_lock(&gpio_lookup_lock
);
2263 list_add_tail(&table
->list
, &gpio_lookup_list
);
2265 mutex_unlock(&gpio_lookup_lock
);
2269 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2270 * @table: table of consumers to unregister
2272 void gpiod_remove_lookup_table(struct gpiod_lookup_table
*table
)
2274 mutex_lock(&gpio_lookup_lock
);
2276 list_del(&table
->list
);
2278 mutex_unlock(&gpio_lookup_lock
);
2281 static struct gpio_desc
*of_find_gpio(struct device
*dev
, const char *con_id
,
2283 enum gpio_lookup_flags
*flags
)
2285 char prop_name
[32]; /* 32 is max size of property name */
2286 enum of_gpio_flags of_flags
;
2287 struct gpio_desc
*desc
;
2290 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2292 snprintf(prop_name
, sizeof(prop_name
), "%s-%s", con_id
,
2295 snprintf(prop_name
, sizeof(prop_name
), "%s",
2298 desc
= of_get_named_gpiod_flags(dev
->of_node
, prop_name
, idx
,
2300 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2307 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2308 *flags
|= GPIO_ACTIVE_LOW
;
2310 if (of_flags
& OF_GPIO_SINGLE_ENDED
) {
2311 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2312 *flags
|= GPIO_OPEN_DRAIN
;
2314 *flags
|= GPIO_OPEN_SOURCE
;
2320 static struct gpio_desc
*acpi_find_gpio(struct device
*dev
,
2323 enum gpiod_flags flags
,
2324 enum gpio_lookup_flags
*lookupflags
)
2326 struct acpi_device
*adev
= ACPI_COMPANION(dev
);
2327 struct acpi_gpio_info info
;
2328 struct gpio_desc
*desc
;
2332 /* Try first from _DSD */
2333 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2334 if (con_id
&& strcmp(con_id
, "gpios")) {
2335 snprintf(propname
, sizeof(propname
), "%s-%s",
2336 con_id
, gpio_suffixes
[i
]);
2338 snprintf(propname
, sizeof(propname
), "%s",
2342 desc
= acpi_get_gpiod_by_index(adev
, propname
, idx
, &info
);
2343 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2347 /* Then from plain _CRS GPIOs */
2349 if (!acpi_can_fallback_to_crs(adev
, con_id
))
2350 return ERR_PTR(-ENOENT
);
2352 desc
= acpi_get_gpiod_by_index(adev
, NULL
, idx
, &info
);
2356 if ((flags
== GPIOD_OUT_LOW
|| flags
== GPIOD_OUT_HIGH
) &&
2358 dev_dbg(dev
, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
2359 return ERR_PTR(-ENOENT
);
2363 if (info
.polarity
== GPIO_ACTIVE_LOW
)
2364 *lookupflags
|= GPIO_ACTIVE_LOW
;
2369 static struct gpiod_lookup_table
*gpiod_find_lookup_table(struct device
*dev
)
2371 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
2372 struct gpiod_lookup_table
*table
;
2374 mutex_lock(&gpio_lookup_lock
);
2376 list_for_each_entry(table
, &gpio_lookup_list
, list
) {
2377 if (table
->dev_id
&& dev_id
) {
2379 * Valid strings on both ends, must be identical to have
2382 if (!strcmp(table
->dev_id
, dev_id
))
2386 * One of the pointers is NULL, so both must be to have
2389 if (dev_id
== table
->dev_id
)
2396 mutex_unlock(&gpio_lookup_lock
);
2400 static struct gpio_desc
*gpiod_find(struct device
*dev
, const char *con_id
,
2402 enum gpio_lookup_flags
*flags
)
2404 struct gpio_desc
*desc
= ERR_PTR(-ENOENT
);
2405 struct gpiod_lookup_table
*table
;
2406 struct gpiod_lookup
*p
;
2408 table
= gpiod_find_lookup_table(dev
);
2412 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2413 struct gpio_chip
*chip
;
2415 /* idx must always match exactly */
2419 /* If the lookup entry has a con_id, require exact match */
2420 if (p
->con_id
&& (!con_id
|| strcmp(p
->con_id
, con_id
)))
2423 chip
= find_chip_by_name(p
->chip_label
);
2426 dev_err(dev
, "cannot find GPIO chip %s\n",
2428 return ERR_PTR(-ENODEV
);
2431 if (chip
->ngpio
<= p
->chip_hwnum
) {
2433 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2434 idx
, chip
->ngpio
, chip
->label
);
2435 return ERR_PTR(-EINVAL
);
2438 desc
= gpiochip_get_desc(chip
, p
->chip_hwnum
);
2447 static int dt_gpio_count(struct device
*dev
, const char *con_id
)
2453 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2455 snprintf(propname
, sizeof(propname
), "%s-%s",
2456 con_id
, gpio_suffixes
[i
]);
2458 snprintf(propname
, sizeof(propname
), "%s",
2461 ret
= of_gpio_named_count(dev
->of_node
, propname
);
2468 static int platform_gpio_count(struct device
*dev
, const char *con_id
)
2470 struct gpiod_lookup_table
*table
;
2471 struct gpiod_lookup
*p
;
2472 unsigned int count
= 0;
2474 table
= gpiod_find_lookup_table(dev
);
2478 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2479 if ((con_id
&& p
->con_id
&& !strcmp(con_id
, p
->con_id
)) ||
2480 (!con_id
&& !p
->con_id
))
2490 * gpiod_count - return the number of GPIOs associated with a device / function
2491 * or -ENOENT if no GPIO has been assigned to the requested function
2492 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2493 * @con_id: function within the GPIO consumer
2495 int gpiod_count(struct device
*dev
, const char *con_id
)
2497 int count
= -ENOENT
;
2499 if (IS_ENABLED(CONFIG_OF
) && dev
&& dev
->of_node
)
2500 count
= dt_gpio_count(dev
, con_id
);
2501 else if (IS_ENABLED(CONFIG_ACPI
) && dev
&& ACPI_HANDLE(dev
))
2502 count
= acpi_gpio_count(dev
, con_id
);
2505 count
= platform_gpio_count(dev
, con_id
);
2509 EXPORT_SYMBOL_GPL(gpiod_count
);
2512 * gpiod_get - obtain a GPIO for a given GPIO function
2513 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2514 * @con_id: function within the GPIO consumer
2515 * @flags: optional GPIO initialization flags
2517 * Return the GPIO descriptor corresponding to the function con_id of device
2518 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2519 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2521 struct gpio_desc
*__must_check
gpiod_get(struct device
*dev
, const char *con_id
,
2522 enum gpiod_flags flags
)
2524 return gpiod_get_index(dev
, con_id
, 0, flags
);
2526 EXPORT_SYMBOL_GPL(gpiod_get
);
2529 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2530 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2531 * @con_id: function within the GPIO consumer
2532 * @flags: optional GPIO initialization flags
2534 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2535 * the requested function it will return NULL. This is convenient for drivers
2536 * that need to handle optional GPIOs.
2538 struct gpio_desc
*__must_check
gpiod_get_optional(struct device
*dev
,
2540 enum gpiod_flags flags
)
2542 return gpiod_get_index_optional(dev
, con_id
, 0, flags
);
2544 EXPORT_SYMBOL_GPL(gpiod_get_optional
);
2547 * gpiod_parse_flags - helper function to parse GPIO lookup flags
2548 * @desc: gpio to be setup
2549 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2552 * Set the GPIO descriptor flags based on the given GPIO lookup flags.
2554 static void gpiod_parse_flags(struct gpio_desc
*desc
, unsigned long lflags
)
2556 if (lflags
& GPIO_ACTIVE_LOW
)
2557 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2558 if (lflags
& GPIO_OPEN_DRAIN
)
2559 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2560 if (lflags
& GPIO_OPEN_SOURCE
)
2561 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2565 * gpiod_configure_flags - helper function to configure a given GPIO
2566 * @desc: gpio whose value will be assigned
2567 * @con_id: function within the GPIO consumer
2568 * @dflags: gpiod_flags - optional GPIO initialization flags
2570 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2571 * requested function and/or index, or another IS_ERR() code if an error
2572 * occurred while trying to acquire the GPIO.
2574 static int gpiod_configure_flags(struct gpio_desc
*desc
, const char *con_id
,
2575 enum gpiod_flags dflags
)
2579 /* No particular flag request, return here... */
2580 if (!(dflags
& GPIOD_FLAGS_BIT_DIR_SET
)) {
2581 pr_debug("no flags found for %s\n", con_id
);
2586 if (dflags
& GPIOD_FLAGS_BIT_DIR_OUT
)
2587 status
= gpiod_direction_output(desc
,
2588 dflags
& GPIOD_FLAGS_BIT_DIR_VAL
);
2590 status
= gpiod_direction_input(desc
);
2596 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2597 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2598 * @con_id: function within the GPIO consumer
2599 * @idx: index of the GPIO to obtain in the consumer
2600 * @flags: optional GPIO initialization flags
2602 * This variant of gpiod_get() allows to access GPIOs other than the first
2603 * defined one for functions that define several GPIOs.
2605 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2606 * requested function and/or index, or another IS_ERR() code if an error
2607 * occurred while trying to acquire the GPIO.
2609 struct gpio_desc
*__must_check
gpiod_get_index(struct device
*dev
,
2612 enum gpiod_flags flags
)
2614 struct gpio_desc
*desc
= NULL
;
2616 enum gpio_lookup_flags lookupflags
= 0;
2618 dev_dbg(dev
, "GPIO lookup for consumer %s\n", con_id
);
2621 /* Using device tree? */
2622 if (IS_ENABLED(CONFIG_OF
) && dev
->of_node
) {
2623 dev_dbg(dev
, "using device tree for GPIO lookup\n");
2624 desc
= of_find_gpio(dev
, con_id
, idx
, &lookupflags
);
2625 } else if (ACPI_COMPANION(dev
)) {
2626 dev_dbg(dev
, "using ACPI for GPIO lookup\n");
2627 desc
= acpi_find_gpio(dev
, con_id
, idx
, flags
, &lookupflags
);
2632 * Either we are not using DT or ACPI, or their lookup did not return
2633 * a result. In that case, use platform lookup as a fallback.
2635 if (!desc
|| desc
== ERR_PTR(-ENOENT
)) {
2636 dev_dbg(dev
, "using lookup tables for GPIO lookup\n");
2637 desc
= gpiod_find(dev
, con_id
, idx
, &lookupflags
);
2641 dev_dbg(dev
, "lookup for GPIO %s failed\n", con_id
);
2645 gpiod_parse_flags(desc
, lookupflags
);
2647 status
= gpiod_request(desc
, con_id
);
2649 return ERR_PTR(status
);
2651 status
= gpiod_configure_flags(desc
, con_id
, flags
);
2653 dev_dbg(dev
, "setup of GPIO %s failed\n", con_id
);
2655 return ERR_PTR(status
);
2660 EXPORT_SYMBOL_GPL(gpiod_get_index
);
2663 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2664 * @fwnode: handle of the firmware node
2665 * @propname: name of the firmware property representing the GPIO
2667 * This function can be used for drivers that get their configuration
2670 * Function properly finds the corresponding GPIO using whatever is the
2671 * underlying firmware interface and then makes sure that the GPIO
2672 * descriptor is requested before it is returned to the caller.
2674 * In case of error an ERR_PTR() is returned.
2676 struct gpio_desc
*fwnode_get_named_gpiod(struct fwnode_handle
*fwnode
,
2677 const char *propname
)
2679 struct gpio_desc
*desc
= ERR_PTR(-ENODEV
);
2680 bool active_low
= false;
2681 bool single_ended
= false;
2685 return ERR_PTR(-EINVAL
);
2687 if (is_of_node(fwnode
)) {
2688 enum of_gpio_flags flags
;
2690 desc
= of_get_named_gpiod_flags(to_of_node(fwnode
), propname
, 0,
2692 if (!IS_ERR(desc
)) {
2693 active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
2694 single_ended
= flags
& OF_GPIO_SINGLE_ENDED
;
2696 } else if (is_acpi_node(fwnode
)) {
2697 struct acpi_gpio_info info
;
2699 desc
= acpi_node_get_gpiod(fwnode
, propname
, 0, &info
);
2701 active_low
= info
.polarity
== GPIO_ACTIVE_LOW
;
2708 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2712 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2714 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2717 ret
= gpiod_request(desc
, NULL
);
2719 return ERR_PTR(ret
);
2723 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod
);
2726 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2728 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2729 * @con_id: function within the GPIO consumer
2730 * @index: index of the GPIO to obtain in the consumer
2731 * @flags: optional GPIO initialization flags
2733 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2734 * specified index was assigned to the requested function it will return NULL.
2735 * This is convenient for drivers that need to handle optional GPIOs.
2737 struct gpio_desc
*__must_check
gpiod_get_index_optional(struct device
*dev
,
2740 enum gpiod_flags flags
)
2742 struct gpio_desc
*desc
;
2744 desc
= gpiod_get_index(dev
, con_id
, index
, flags
);
2746 if (PTR_ERR(desc
) == -ENOENT
)
2752 EXPORT_SYMBOL_GPL(gpiod_get_index_optional
);
2755 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2756 * @desc: gpio whose value will be assigned
2757 * @name: gpio line name
2758 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2760 * @dflags: gpiod_flags - optional GPIO initialization flags
2762 int gpiod_hog(struct gpio_desc
*desc
, const char *name
,
2763 unsigned long lflags
, enum gpiod_flags dflags
)
2765 struct gpio_chip
*chip
;
2766 struct gpio_desc
*local_desc
;
2770 chip
= gpiod_to_chip(desc
);
2771 hwnum
= gpio_chip_hwgpio(desc
);
2773 gpiod_parse_flags(desc
, lflags
);
2775 local_desc
= gpiochip_request_own_desc(chip
, hwnum
, name
);
2776 if (IS_ERR(local_desc
)) {
2777 status
= PTR_ERR(local_desc
);
2778 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
2779 name
, chip
->label
, hwnum
, status
);
2783 status
= gpiod_configure_flags(desc
, name
, dflags
);
2785 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
2786 name
, chip
->label
, hwnum
, status
);
2787 gpiochip_free_own_desc(desc
);
2791 /* Mark GPIO as hogged so it can be identified and removed later */
2792 set_bit(FLAG_IS_HOGGED
, &desc
->flags
);
2794 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2795 desc_to_gpio(desc
), name
,
2796 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ? "output" : "input",
2797 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ?
2798 (dflags
&GPIOD_FLAGS_BIT_DIR_VAL
) ? "/high" : "/low":"");
2804 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2805 * @chip: gpio chip to act on
2807 * This is only used by of_gpiochip_remove to free hogged gpios
2809 static void gpiochip_free_hogs(struct gpio_chip
*chip
)
2813 for (id
= 0; id
< chip
->ngpio
; id
++) {
2814 if (test_bit(FLAG_IS_HOGGED
, &chip
->gpiodev
->descs
[id
].flags
))
2815 gpiochip_free_own_desc(&chip
->gpiodev
->descs
[id
]);
2820 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2821 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2822 * @con_id: function within the GPIO consumer
2823 * @flags: optional GPIO initialization flags
2825 * This function acquires all the GPIOs defined under a given function.
2827 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2828 * no GPIO has been assigned to the requested function, or another IS_ERR()
2829 * code if an error occurred while trying to acquire the GPIOs.
2831 struct gpio_descs
*__must_check
gpiod_get_array(struct device
*dev
,
2833 enum gpiod_flags flags
)
2835 struct gpio_desc
*desc
;
2836 struct gpio_descs
*descs
;
2839 count
= gpiod_count(dev
, con_id
);
2841 return ERR_PTR(count
);
2843 descs
= kzalloc(sizeof(*descs
) + sizeof(descs
->desc
[0]) * count
,
2846 return ERR_PTR(-ENOMEM
);
2848 for (descs
->ndescs
= 0; descs
->ndescs
< count
; ) {
2849 desc
= gpiod_get_index(dev
, con_id
, descs
->ndescs
, flags
);
2851 gpiod_put_array(descs
);
2852 return ERR_CAST(desc
);
2854 descs
->desc
[descs
->ndescs
] = desc
;
2859 EXPORT_SYMBOL_GPL(gpiod_get_array
);
2862 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2864 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2865 * @con_id: function within the GPIO consumer
2866 * @flags: optional GPIO initialization flags
2868 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2869 * assigned to the requested function it will return NULL.
2871 struct gpio_descs
*__must_check
gpiod_get_array_optional(struct device
*dev
,
2873 enum gpiod_flags flags
)
2875 struct gpio_descs
*descs
;
2877 descs
= gpiod_get_array(dev
, con_id
, flags
);
2878 if (IS_ERR(descs
) && (PTR_ERR(descs
) == -ENOENT
))
2883 EXPORT_SYMBOL_GPL(gpiod_get_array_optional
);
2886 * gpiod_put - dispose of a GPIO descriptor
2887 * @desc: GPIO descriptor to dispose of
2889 * No descriptor can be used after gpiod_put() has been called on it.
2891 void gpiod_put(struct gpio_desc
*desc
)
2895 EXPORT_SYMBOL_GPL(gpiod_put
);
2898 * gpiod_put_array - dispose of multiple GPIO descriptors
2899 * @descs: struct gpio_descs containing an array of descriptors
2901 void gpiod_put_array(struct gpio_descs
*descs
)
2905 for (i
= 0; i
< descs
->ndescs
; i
++)
2906 gpiod_put(descs
->desc
[i
]);
2910 EXPORT_SYMBOL_GPL(gpiod_put_array
);
2912 static int __init
gpiolib_dev_init(void)
2916 /* Register GPIO sysfs bus */
2917 ret
= bus_register(&gpio_bus_type
);
2919 pr_err("gpiolib: could not register GPIO bus type\n");
2923 ret
= alloc_chrdev_region(&gpio_devt
, 0, GPIO_DEV_MAX
, "gpiochip");
2925 pr_err("gpiolib: failed to allocate char dev region\n");
2926 bus_unregister(&gpio_bus_type
);
2928 gpiolib_initialized
= true;
2929 gpiochip_setup_devs();
2933 core_initcall(gpiolib_dev_init
);
2935 #ifdef CONFIG_DEBUG_FS
2937 static void gpiolib_dbg_show(struct seq_file
*s
, struct gpio_device
*gdev
)
2940 struct gpio_chip
*chip
= gdev
->chip
;
2941 unsigned gpio
= gdev
->base
;
2942 struct gpio_desc
*gdesc
= &gdev
->descs
[0];
2946 for (i
= 0; i
< gdev
->ngpio
; i
++, gpio
++, gdesc
++) {
2947 if (!test_bit(FLAG_REQUESTED
, &gdesc
->flags
)) {
2949 seq_printf(s
, " gpio-%-3d (%-20.20s)\n",
2955 gpiod_get_direction(gdesc
);
2956 is_out
= test_bit(FLAG_IS_OUT
, &gdesc
->flags
);
2957 is_irq
= test_bit(FLAG_USED_AS_IRQ
, &gdesc
->flags
);
2958 seq_printf(s
, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2959 gpio
, gdesc
->name
? gdesc
->name
: "", gdesc
->label
,
2960 is_out
? "out" : "in ",
2962 ? (chip
->get(chip
, i
) ? "hi" : "lo")
2964 is_irq
? "IRQ" : " ");
2965 seq_printf(s
, "\n");
2969 static void *gpiolib_seq_start(struct seq_file
*s
, loff_t
*pos
)
2971 unsigned long flags
;
2972 struct gpio_device
*gdev
= NULL
;
2973 loff_t index
= *pos
;
2977 spin_lock_irqsave(&gpio_lock
, flags
);
2978 list_for_each_entry(gdev
, &gpio_devices
, list
)
2980 spin_unlock_irqrestore(&gpio_lock
, flags
);
2983 spin_unlock_irqrestore(&gpio_lock
, flags
);
2988 static void *gpiolib_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
2990 unsigned long flags
;
2991 struct gpio_device
*gdev
= v
;
2994 spin_lock_irqsave(&gpio_lock
, flags
);
2995 if (list_is_last(&gdev
->list
, &gpio_devices
))
2998 ret
= list_entry(gdev
->list
.next
, struct gpio_device
, list
);
2999 spin_unlock_irqrestore(&gpio_lock
, flags
);
3007 static void gpiolib_seq_stop(struct seq_file
*s
, void *v
)
3011 static int gpiolib_seq_show(struct seq_file
*s
, void *v
)
3013 struct gpio_device
*gdev
= v
;
3014 struct gpio_chip
*chip
= gdev
->chip
;
3015 struct device
*parent
;
3018 seq_printf(s
, "%s%s: (dangling chip)", (char *)s
->private,
3019 dev_name(&gdev
->dev
));
3023 seq_printf(s
, "%s%s: GPIOs %d-%d", (char *)s
->private,
3024 dev_name(&gdev
->dev
),
3025 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1);
3026 parent
= chip
->parent
;
3028 seq_printf(s
, ", parent: %s/%s",
3029 parent
->bus
? parent
->bus
->name
: "no-bus",
3032 seq_printf(s
, ", %s", chip
->label
);
3033 if (chip
->can_sleep
)
3034 seq_printf(s
, ", can sleep");
3035 seq_printf(s
, ":\n");
3038 chip
->dbg_show(s
, chip
);
3040 gpiolib_dbg_show(s
, gdev
);
3045 static const struct seq_operations gpiolib_seq_ops
= {
3046 .start
= gpiolib_seq_start
,
3047 .next
= gpiolib_seq_next
,
3048 .stop
= gpiolib_seq_stop
,
3049 .show
= gpiolib_seq_show
,
3052 static int gpiolib_open(struct inode
*inode
, struct file
*file
)
3054 return seq_open(file
, &gpiolib_seq_ops
);
3057 static const struct file_operations gpiolib_operations
= {
3058 .owner
= THIS_MODULE
,
3059 .open
= gpiolib_open
,
3061 .llseek
= seq_lseek
,
3062 .release
= seq_release
,
3065 static int __init
gpiolib_debugfs_init(void)
3067 /* /sys/kernel/debug/gpio */
3068 (void) debugfs_create_file("gpio", S_IFREG
| S_IRUGO
,
3069 NULL
, NULL
, &gpiolib_operations
);
3072 subsys_initcall(gpiolib_debugfs_init
);
3074 #endif /* DEBUG_FS */