2 * ACPI helpers for GPIO API
4 * Copyright (C) 2012, Intel Corporation
5 * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
6 * Mika Westerberg <mika.westerberg@linux.intel.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/errno.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/export.h>
17 #include <linux/acpi.h>
18 #include <linux/interrupt.h>
19 #include <linux/mutex.h>
23 struct acpi_gpio_event
{
24 struct list_head node
;
28 struct gpio_desc
*desc
;
31 struct acpi_gpio_connection
{
32 struct list_head node
;
34 struct gpio_desc
*desc
;
37 struct acpi_gpio_chip
{
39 * ACPICA requires that the first field of the context parameter
40 * passed to acpi_install_address_space_handler() is large enough
41 * to hold struct acpi_connection_info.
43 struct acpi_connection_info conn_info
;
44 struct list_head conns
;
45 struct mutex conn_lock
;
46 struct gpio_chip
*chip
;
47 struct list_head events
;
50 static int acpi_gpiochip_find(struct gpio_chip
*gc
, void *data
)
55 return ACPI_HANDLE(gc
->dev
) == data
;
59 * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
60 * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
61 * @pin: ACPI GPIO pin number (0-based, controller-relative)
63 * Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
67 static struct gpio_desc
*acpi_get_gpiod(char *path
, int pin
)
69 struct gpio_chip
*chip
;
73 status
= acpi_get_handle(NULL
, path
, &handle
);
74 if (ACPI_FAILURE(status
))
75 return ERR_PTR(-ENODEV
);
77 chip
= gpiochip_find(handle
, acpi_gpiochip_find
);
79 return ERR_PTR(-ENODEV
);
81 if (pin
< 0 || pin
> chip
->ngpio
)
82 return ERR_PTR(-EINVAL
);
84 return gpiochip_get_desc(chip
, pin
);
87 static irqreturn_t
acpi_gpio_irq_handler(int irq
, void *data
)
89 struct acpi_gpio_event
*event
= data
;
91 acpi_evaluate_object(event
->handle
, NULL
, NULL
, NULL
);
96 static irqreturn_t
acpi_gpio_irq_handler_evt(int irq
, void *data
)
98 struct acpi_gpio_event
*event
= data
;
100 acpi_execute_simple_method(event
->handle
, NULL
, event
->pin
);
105 static void acpi_gpio_chip_dh(acpi_handle handle
, void *data
)
107 /* The address of this function is used as a key. */
110 static acpi_status
acpi_gpiochip_request_interrupt(struct acpi_resource
*ares
,
113 struct acpi_gpio_chip
*acpi_gpio
= context
;
114 struct gpio_chip
*chip
= acpi_gpio
->chip
;
115 struct acpi_resource_gpio
*agpio
;
116 acpi_handle handle
, evt_handle
;
117 struct acpi_gpio_event
*event
;
118 irq_handler_t handler
= NULL
;
119 struct gpio_desc
*desc
;
120 unsigned long irqflags
;
123 if (ares
->type
!= ACPI_RESOURCE_TYPE_GPIO
)
126 agpio
= &ares
->data
.gpio
;
127 if (agpio
->connection_type
!= ACPI_RESOURCE_GPIO_TYPE_INT
)
130 handle
= ACPI_HANDLE(chip
->dev
);
131 pin
= agpio
->pin_table
[0];
135 sprintf(ev_name
, "_%c%02X",
136 agpio
->triggering
== ACPI_EDGE_SENSITIVE
? 'E' : 'L',
138 if (ACPI_SUCCESS(acpi_get_handle(handle
, ev_name
, &evt_handle
)))
139 handler
= acpi_gpio_irq_handler
;
142 if (ACPI_SUCCESS(acpi_get_handle(handle
, "_EVT", &evt_handle
)))
143 handler
= acpi_gpio_irq_handler_evt
;
146 return AE_BAD_PARAMETER
;
148 desc
= gpiochip_request_own_desc(chip
, pin
, "ACPI:Event");
150 dev_err(chip
->dev
, "Failed to request GPIO\n");
154 gpiod_direction_input(desc
);
156 ret
= gpio_lock_as_irq(chip
, pin
);
158 dev_err(chip
->dev
, "Failed to lock GPIO as interrupt\n");
162 irq
= gpiod_to_irq(desc
);
164 dev_err(chip
->dev
, "Failed to translate GPIO to IRQ\n");
165 goto fail_unlock_irq
;
168 irqflags
= IRQF_ONESHOT
;
169 if (agpio
->triggering
== ACPI_LEVEL_SENSITIVE
) {
170 if (agpio
->polarity
== ACPI_ACTIVE_HIGH
)
171 irqflags
|= IRQF_TRIGGER_HIGH
;
173 irqflags
|= IRQF_TRIGGER_LOW
;
175 switch (agpio
->polarity
) {
176 case ACPI_ACTIVE_HIGH
:
177 irqflags
|= IRQF_TRIGGER_RISING
;
179 case ACPI_ACTIVE_LOW
:
180 irqflags
|= IRQF_TRIGGER_FALLING
;
183 irqflags
|= IRQF_TRIGGER_RISING
|
184 IRQF_TRIGGER_FALLING
;
189 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
191 goto fail_unlock_irq
;
193 event
->handle
= evt_handle
;
198 ret
= request_threaded_irq(event
->irq
, NULL
, handler
, irqflags
,
199 "ACPI:Event", event
);
201 dev_err(chip
->dev
, "Failed to setup interrupt handler for %d\n",
203 goto fail_free_event
;
206 list_add_tail(&event
->node
, &acpi_gpio
->events
);
212 gpio_unlock_as_irq(chip
, pin
);
214 gpiochip_free_own_desc(desc
);
220 * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
223 * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
224 * handled by ACPI event methods which need to be called from the GPIO
225 * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
226 * gpio pins have acpi event methods and assigns interrupt handlers that calls
227 * the acpi event methods for those pins.
229 void acpi_gpiochip_request_interrupts(struct gpio_chip
*chip
)
231 struct acpi_gpio_chip
*acpi_gpio
;
235 if (!chip
->dev
|| !chip
->to_irq
)
238 handle
= ACPI_HANDLE(chip
->dev
);
242 status
= acpi_get_data(handle
, acpi_gpio_chip_dh
, (void **)&acpi_gpio
);
243 if (ACPI_FAILURE(status
))
246 INIT_LIST_HEAD(&acpi_gpio
->events
);
247 acpi_walk_resources(ACPI_HANDLE(chip
->dev
), "_AEI",
248 acpi_gpiochip_request_interrupt
, acpi_gpio
);
252 * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
255 * Free interrupts associated with GPIO ACPI event method for the given
258 void acpi_gpiochip_free_interrupts(struct gpio_chip
*chip
)
260 struct acpi_gpio_chip
*acpi_gpio
;
261 struct acpi_gpio_event
*event
, *ep
;
265 if (!chip
->dev
|| !chip
->to_irq
)
268 handle
= ACPI_HANDLE(chip
->dev
);
272 status
= acpi_get_data(handle
, acpi_gpio_chip_dh
, (void **)&acpi_gpio
);
273 if (ACPI_FAILURE(status
))
276 list_for_each_entry_safe_reverse(event
, ep
, &acpi_gpio
->events
, node
) {
277 struct gpio_desc
*desc
;
279 free_irq(event
->irq
, event
);
281 if (WARN_ON(IS_ERR(desc
)))
283 gpio_unlock_as_irq(chip
, event
->pin
);
284 gpiochip_free_own_desc(desc
);
285 list_del(&event
->node
);
290 struct acpi_gpio_lookup
{
291 struct acpi_gpio_info info
;
293 struct gpio_desc
*desc
;
297 static int acpi_find_gpio(struct acpi_resource
*ares
, void *data
)
299 struct acpi_gpio_lookup
*lookup
= data
;
301 if (ares
->type
!= ACPI_RESOURCE_TYPE_GPIO
)
304 if (lookup
->n
++ == lookup
->index
&& !lookup
->desc
) {
305 const struct acpi_resource_gpio
*agpio
= &ares
->data
.gpio
;
307 lookup
->desc
= acpi_get_gpiod(agpio
->resource_source
.string_ptr
,
308 agpio
->pin_table
[0]);
309 lookup
->info
.gpioint
=
310 agpio
->connection_type
== ACPI_RESOURCE_GPIO_TYPE_INT
;
311 lookup
->info
.active_low
=
312 agpio
->polarity
== ACPI_ACTIVE_LOW
;
319 * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
320 * @dev: pointer to a device to get GPIO from
321 * @index: index of GpioIo/GpioInt resource (starting from %0)
322 * @info: info pointer to fill in (optional)
324 * Function goes through ACPI resources for @dev and based on @index looks
325 * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
326 * and returns it. @index matches GpioIo/GpioInt resources only so if there
327 * are total %3 GPIO resources, the index goes from %0 to %2.
329 * If the GPIO cannot be translated or there is an error an ERR_PTR is
332 * Note: if the GPIO resource has multiple entries in the pin list, this
333 * function only returns the first.
335 struct gpio_desc
*acpi_get_gpiod_by_index(struct device
*dev
, int index
,
336 struct acpi_gpio_info
*info
)
338 struct acpi_gpio_lookup lookup
;
339 struct list_head resource_list
;
340 struct acpi_device
*adev
;
345 return ERR_PTR(-EINVAL
);
347 handle
= ACPI_HANDLE(dev
);
348 if (!handle
|| acpi_bus_get_device(handle
, &adev
))
349 return ERR_PTR(-ENODEV
);
351 memset(&lookup
, 0, sizeof(lookup
));
352 lookup
.index
= index
;
354 INIT_LIST_HEAD(&resource_list
);
355 ret
= acpi_dev_get_resources(adev
, &resource_list
, acpi_find_gpio
,
360 acpi_dev_free_resource_list(&resource_list
);
362 if (lookup
.desc
&& info
)
365 return lookup
.desc
? lookup
.desc
: ERR_PTR(-ENOENT
);
369 acpi_gpio_adr_space_handler(u32 function
, acpi_physical_address address
,
370 u32 bits
, u64
*value
, void *handler_context
,
371 void *region_context
)
373 struct acpi_gpio_chip
*achip
= region_context
;
374 struct gpio_chip
*chip
= achip
->chip
;
375 struct acpi_resource_gpio
*agpio
;
376 struct acpi_resource
*ares
;
377 int pin_index
= (int)address
;
383 status
= acpi_buffer_to_resource(achip
->conn_info
.connection
,
384 achip
->conn_info
.length
, &ares
);
385 if (ACPI_FAILURE(status
))
388 if (WARN_ON(ares
->type
!= ACPI_RESOURCE_TYPE_GPIO
)) {
390 return AE_BAD_PARAMETER
;
393 agpio
= &ares
->data
.gpio
;
394 pull_up
= agpio
->pin_config
== ACPI_PIN_CONFIG_PULLUP
;
396 if (WARN_ON(agpio
->io_restriction
== ACPI_IO_RESTRICT_INPUT
&&
397 function
== ACPI_WRITE
)) {
399 return AE_BAD_PARAMETER
;
402 length
= min(agpio
->pin_table_length
, (u16
)(pin_index
+ bits
));
403 for (i
= pin_index
; i
< length
; ++i
) {
404 unsigned pin
= agpio
->pin_table
[i
];
405 struct acpi_gpio_connection
*conn
;
406 struct gpio_desc
*desc
;
409 mutex_lock(&achip
->conn_lock
);
412 list_for_each_entry(conn
, &achip
->conns
, node
) {
413 if (conn
->pin
== pin
) {
420 desc
= gpiochip_request_own_desc(chip
, pin
,
424 mutex_unlock(&achip
->conn_lock
);
428 switch (agpio
->io_restriction
) {
429 case ACPI_IO_RESTRICT_INPUT
:
430 gpiod_direction_input(desc
);
432 case ACPI_IO_RESTRICT_OUTPUT
:
434 * ACPI GPIO resources don't contain an
435 * initial value for the GPIO. Therefore we
436 * deduce that value from the pull field
437 * instead. If the pin is pulled up we
438 * assume default to be high, otherwise
441 gpiod_direction_output(desc
, pull_up
);
445 * Assume that the BIOS has configured the
446 * direction and pull accordingly.
451 conn
= kzalloc(sizeof(*conn
), GFP_KERNEL
);
453 status
= AE_NO_MEMORY
;
454 gpiochip_free_own_desc(desc
);
455 mutex_unlock(&achip
->conn_lock
);
461 list_add_tail(&conn
->node
, &achip
->conns
);
464 mutex_unlock(&achip
->conn_lock
);
466 if (function
== ACPI_WRITE
)
467 gpiod_set_raw_value_cansleep(desc
,
468 !!((1 << i
) & *value
));
470 *value
|= (u64
)gpiod_get_raw_value_cansleep(desc
) << i
;
478 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip
*achip
)
480 struct gpio_chip
*chip
= achip
->chip
;
481 acpi_handle handle
= ACPI_HANDLE(chip
->dev
);
484 INIT_LIST_HEAD(&achip
->conns
);
485 mutex_init(&achip
->conn_lock
);
486 status
= acpi_install_address_space_handler(handle
, ACPI_ADR_SPACE_GPIO
,
487 acpi_gpio_adr_space_handler
,
489 if (ACPI_FAILURE(status
))
490 dev_err(chip
->dev
, "Failed to install GPIO OpRegion handler\n");
493 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip
*achip
)
495 struct gpio_chip
*chip
= achip
->chip
;
496 acpi_handle handle
= ACPI_HANDLE(chip
->dev
);
497 struct acpi_gpio_connection
*conn
, *tmp
;
500 status
= acpi_remove_address_space_handler(handle
, ACPI_ADR_SPACE_GPIO
,
501 acpi_gpio_adr_space_handler
);
502 if (ACPI_FAILURE(status
)) {
503 dev_err(chip
->dev
, "Failed to remove GPIO OpRegion handler\n");
507 list_for_each_entry_safe_reverse(conn
, tmp
, &achip
->conns
, node
) {
508 gpiochip_free_own_desc(conn
->desc
);
509 list_del(&conn
->node
);
514 void acpi_gpiochip_add(struct gpio_chip
*chip
)
516 struct acpi_gpio_chip
*acpi_gpio
;
520 if (!chip
|| !chip
->dev
)
523 handle
= ACPI_HANDLE(chip
->dev
);
527 acpi_gpio
= kzalloc(sizeof(*acpi_gpio
), GFP_KERNEL
);
530 "Failed to allocate memory for ACPI GPIO chip\n");
534 acpi_gpio
->chip
= chip
;
536 status
= acpi_attach_data(handle
, acpi_gpio_chip_dh
, acpi_gpio
);
537 if (ACPI_FAILURE(status
)) {
538 dev_err(chip
->dev
, "Failed to attach ACPI GPIO chip\n");
543 acpi_gpiochip_request_regions(acpi_gpio
);
546 void acpi_gpiochip_remove(struct gpio_chip
*chip
)
548 struct acpi_gpio_chip
*acpi_gpio
;
552 if (!chip
|| !chip
->dev
)
555 handle
= ACPI_HANDLE(chip
->dev
);
559 status
= acpi_get_data(handle
, acpi_gpio_chip_dh
, (void **)&acpi_gpio
);
560 if (ACPI_FAILURE(status
)) {
561 dev_warn(chip
->dev
, "Failed to retrieve ACPI GPIO chip\n");
565 acpi_gpiochip_free_regions(acpi_gpio
);
567 acpi_detach_data(handle
, acpi_gpio_chip_dh
);