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Mathias Nymane29482e2012-11-30 12:37:36 +01001/*
2 * ACPI helpers for GPIO API
3 *
4 * Copyright (C) 2012, Intel Corporation
5 * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
6 * Mika Westerberg <mika.westerberg@linux.intel.com>
7 *
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.
11 */
12
13#include <linux/errno.h>
Mika Westerberg936e15d2013-10-10 11:01:08 +030014#include <linux/gpio/consumer.h>
Mika Westerberg5ccff852014-01-08 12:40:56 +020015#include <linux/gpio/driver.h>
Mathias Nymane29482e2012-11-30 12:37:36 +010016#include <linux/export.h>
Mathias Nymane29482e2012-11-30 12:37:36 +010017#include <linux/acpi.h>
Mathias Nyman0d1c28a2013-01-28 16:23:10 +020018#include <linux/interrupt.h>
Mathias Nymane29482e2012-11-30 12:37:36 +010019
Mika Westerberg5ccff852014-01-08 12:40:56 +020020#include "gpiolib.h"
21
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +020022struct acpi_gpio_evt_pin {
23 struct list_head node;
24 acpi_handle *evt_handle;
25 unsigned int pin;
26 unsigned int irq;
27};
28
Mathias Nymane29482e2012-11-30 12:37:36 +010029static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
30{
31 if (!gc->dev)
32 return false;
33
34 return ACPI_HANDLE(gc->dev) == data;
35}
36
37/**
Mika Westerberg936e15d2013-10-10 11:01:08 +030038 * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
Mathias Nymane29482e2012-11-30 12:37:36 +010039 * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
40 * @pin: ACPI GPIO pin number (0-based, controller-relative)
41 *
Mika Westerberg936e15d2013-10-10 11:01:08 +030042 * Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
43 * error value
Mathias Nymane29482e2012-11-30 12:37:36 +010044 */
45
Mika Westerberg936e15d2013-10-10 11:01:08 +030046static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
Mathias Nymane29482e2012-11-30 12:37:36 +010047{
48 struct gpio_chip *chip;
49 acpi_handle handle;
50 acpi_status status;
51
52 status = acpi_get_handle(NULL, path, &handle);
53 if (ACPI_FAILURE(status))
Mika Westerberg936e15d2013-10-10 11:01:08 +030054 return ERR_PTR(-ENODEV);
Mathias Nymane29482e2012-11-30 12:37:36 +010055
56 chip = gpiochip_find(handle, acpi_gpiochip_find);
57 if (!chip)
Mika Westerberg936e15d2013-10-10 11:01:08 +030058 return ERR_PTR(-ENODEV);
Mathias Nymane29482e2012-11-30 12:37:36 +010059
Mika Westerberg936e15d2013-10-10 11:01:08 +030060 if (pin < 0 || pin > chip->ngpio)
61 return ERR_PTR(-EINVAL);
Mathias Nymane29482e2012-11-30 12:37:36 +010062
Mika Westerberg936e15d2013-10-10 11:01:08 +030063 return gpio_to_desc(chip->base + pin);
Mathias Nymane29482e2012-11-30 12:37:36 +010064}
Mathias Nyman0d1c28a2013-01-28 16:23:10 +020065
Mathias Nyman0d1c28a2013-01-28 16:23:10 +020066static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
67{
68 acpi_handle handle = data;
69
70 acpi_evaluate_object(handle, NULL, NULL, NULL);
71
72 return IRQ_HANDLED;
73}
74
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +020075static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
76{
77 struct acpi_gpio_evt_pin *evt_pin = data;
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +020078
Zhang Rui524c1082013-09-03 08:31:50 +080079 acpi_execute_simple_method(evt_pin->evt_handle, NULL, evt_pin->pin);
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +020080
81 return IRQ_HANDLED;
82}
83
84static void acpi_gpio_evt_dh(acpi_handle handle, void *data)
85{
86 /* The address of this function is used as a key. */
87}
88
Mathias Nyman0d1c28a2013-01-28 16:23:10 +020089/**
90 * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
91 * @chip: gpio chip
92 *
93 * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
94 * handled by ACPI event methods which need to be called from the GPIO
95 * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
96 * gpio pins have acpi event methods and assigns interrupt handlers that calls
97 * the acpi event methods for those pins.
Mathias Nyman0d1c28a2013-01-28 16:23:10 +020098 */
Mika Westerberg664e3e52014-01-08 12:40:54 +020099static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200100{
101 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
102 struct acpi_resource *res;
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +0200103 acpi_handle handle, evt_handle;
104 struct list_head *evt_pins = NULL;
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200105 acpi_status status;
Mathias Nyman1107ca12013-02-04 11:32:22 +0200106 unsigned int pin;
107 int irq, ret;
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200108 char ev_name[5];
109
110 if (!chip->dev || !chip->to_irq)
111 return;
112
113 handle = ACPI_HANDLE(chip->dev);
114 if (!handle)
115 return;
116
117 status = acpi_get_event_resources(handle, &buf);
118 if (ACPI_FAILURE(status))
119 return;
120
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +0200121 status = acpi_get_handle(handle, "_EVT", &evt_handle);
122 if (ACPI_SUCCESS(status)) {
123 evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL);
124 if (evt_pins) {
125 INIT_LIST_HEAD(evt_pins);
126 status = acpi_attach_data(handle, acpi_gpio_evt_dh,
127 evt_pins);
128 if (ACPI_FAILURE(status)) {
129 kfree(evt_pins);
130 evt_pins = NULL;
131 }
132 }
133 }
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200134
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +0200135 /*
136 * If a GPIO interrupt has an ACPI event handler method, or _EVT is
137 * present, set up an interrupt handler that calls the ACPI event
138 * handler.
139 */
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200140 for (res = buf.pointer;
141 res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
142 res = ACPI_NEXT_RESOURCE(res)) {
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +0200143 irq_handler_t handler = NULL;
144 void *data;
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200145
146 if (res->type != ACPI_RESOURCE_TYPE_GPIO ||
147 res->data.gpio.connection_type !=
148 ACPI_RESOURCE_GPIO_TYPE_INT)
149 continue;
150
151 pin = res->data.gpio.pin_table[0];
152 if (pin > chip->ngpio)
153 continue;
154
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200155 irq = chip->to_irq(chip, pin);
156 if (irq < 0)
157 continue;
158
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +0200159 if (pin <= 255) {
160 acpi_handle ev_handle;
161
162 sprintf(ev_name, "_%c%02X",
163 res->data.gpio.triggering ? 'E' : 'L', pin);
164 status = acpi_get_handle(handle, ev_name, &ev_handle);
165 if (ACPI_SUCCESS(status)) {
166 handler = acpi_gpio_irq_handler;
167 data = ev_handle;
168 }
169 }
170 if (!handler && evt_pins) {
171 struct acpi_gpio_evt_pin *evt_pin;
172
173 evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL);
174 if (!evt_pin)
175 continue;
176
177 list_add_tail(&evt_pin->node, evt_pins);
178 evt_pin->evt_handle = evt_handle;
179 evt_pin->pin = pin;
180 evt_pin->irq = irq;
181 handler = acpi_gpio_irq_handler_evt;
182 data = evt_pin;
183 }
184 if (!handler)
185 continue;
186
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200187 /* Assume BIOS sets the triggering, so no flags */
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +0200188 ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler,
189 0, "GPIO-signaled-ACPI-event",
190 data);
Mathias Nyman1107ca12013-02-04 11:32:22 +0200191 if (ret)
192 dev_err(chip->dev,
193 "Failed to request IRQ %d ACPI event handler\n",
194 irq);
Mathias Nyman0d1c28a2013-01-28 16:23:10 +0200195 }
196}
Rafael J. Wysocki7fc7acb2013-04-09 15:57:25 +0200197
Mika Westerberg70b53412013-10-10 11:01:07 +0300198/**
199 * acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.
200 * @chip: gpio chip
201 *
202 * Free interrupts associated with the _EVT method for the given GPIO chip.
203 *
204 * The remaining ACPI event interrupts associated with the chip are freed
205 * automatically.
206 */
Mika Westerberg664e3e52014-01-08 12:40:54 +0200207static void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
Mika Westerberg70b53412013-10-10 11:01:07 +0300208{
209 acpi_handle handle;
210 acpi_status status;
211 struct list_head *evt_pins;
212 struct acpi_gpio_evt_pin *evt_pin, *ep;
213
214 if (!chip->dev || !chip->to_irq)
215 return;
216
217 handle = ACPI_HANDLE(chip->dev);
218 if (!handle)
219 return;
220
221 status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins);
222 if (ACPI_FAILURE(status))
223 return;
224
225 list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) {
226 devm_free_irq(chip->dev, evt_pin->irq, evt_pin);
227 list_del(&evt_pin->node);
228 kfree(evt_pin);
229 }
230
231 acpi_detach_data(handle, acpi_gpio_evt_dh);
232 kfree(evt_pins);
233}
Mika Westerberg70b53412013-10-10 11:01:07 +0300234
Mika Westerberg12028d22013-04-03 13:56:54 +0300235struct acpi_gpio_lookup {
236 struct acpi_gpio_info info;
237 int index;
Mika Westerberg936e15d2013-10-10 11:01:08 +0300238 struct gpio_desc *desc;
Mika Westerberg12028d22013-04-03 13:56:54 +0300239 int n;
240};
241
242static int acpi_find_gpio(struct acpi_resource *ares, void *data)
243{
244 struct acpi_gpio_lookup *lookup = data;
245
246 if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
247 return 1;
248
Mika Westerberg936e15d2013-10-10 11:01:08 +0300249 if (lookup->n++ == lookup->index && !lookup->desc) {
Mika Westerberg12028d22013-04-03 13:56:54 +0300250 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
251
Mika Westerberg936e15d2013-10-10 11:01:08 +0300252 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
253 agpio->pin_table[0]);
Mika Westerberg12028d22013-04-03 13:56:54 +0300254 lookup->info.gpioint =
255 agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
Mika Westerberge01f4402013-10-10 11:01:10 +0300256 lookup->info.active_low =
257 agpio->polarity == ACPI_ACTIVE_LOW;
Mika Westerberg12028d22013-04-03 13:56:54 +0300258 }
259
260 return 1;
261}
262
263/**
Mika Westerberg936e15d2013-10-10 11:01:08 +0300264 * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
Mika Westerberg12028d22013-04-03 13:56:54 +0300265 * @dev: pointer to a device to get GPIO from
266 * @index: index of GpioIo/GpioInt resource (starting from %0)
267 * @info: info pointer to fill in (optional)
268 *
269 * Function goes through ACPI resources for @dev and based on @index looks
Mika Westerberg936e15d2013-10-10 11:01:08 +0300270 * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
Mika Westerberg12028d22013-04-03 13:56:54 +0300271 * and returns it. @index matches GpioIo/GpioInt resources only so if there
272 * are total %3 GPIO resources, the index goes from %0 to %2.
273 *
Mika Westerberg936e15d2013-10-10 11:01:08 +0300274 * If the GPIO cannot be translated or there is an error an ERR_PTR is
Mika Westerberg12028d22013-04-03 13:56:54 +0300275 * returned.
276 *
277 * Note: if the GPIO resource has multiple entries in the pin list, this
278 * function only returns the first.
279 */
Mika Westerberg936e15d2013-10-10 11:01:08 +0300280struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index,
281 struct acpi_gpio_info *info)
Mika Westerberg12028d22013-04-03 13:56:54 +0300282{
283 struct acpi_gpio_lookup lookup;
284 struct list_head resource_list;
285 struct acpi_device *adev;
286 acpi_handle handle;
287 int ret;
288
289 if (!dev)
Mika Westerberg936e15d2013-10-10 11:01:08 +0300290 return ERR_PTR(-EINVAL);
Mika Westerberg12028d22013-04-03 13:56:54 +0300291
292 handle = ACPI_HANDLE(dev);
293 if (!handle || acpi_bus_get_device(handle, &adev))
Mika Westerberg936e15d2013-10-10 11:01:08 +0300294 return ERR_PTR(-ENODEV);
Mika Westerberg12028d22013-04-03 13:56:54 +0300295
296 memset(&lookup, 0, sizeof(lookup));
297 lookup.index = index;
Mika Westerberg12028d22013-04-03 13:56:54 +0300298
299 INIT_LIST_HEAD(&resource_list);
300 ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
301 &lookup);
302 if (ret < 0)
Mika Westerberg936e15d2013-10-10 11:01:08 +0300303 return ERR_PTR(ret);
Mika Westerberg12028d22013-04-03 13:56:54 +0300304
305 acpi_dev_free_resource_list(&resource_list);
306
Mika Westerberg936e15d2013-10-10 11:01:08 +0300307 if (lookup.desc && info)
Mika Westerberg12028d22013-04-03 13:56:54 +0300308 *info = lookup.info;
309
Mika Westerberga00580c2013-12-10 12:00:27 +0200310 return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
Mika Westerberg12028d22013-04-03 13:56:54 +0300311}
Mika Westerberg664e3e52014-01-08 12:40:54 +0200312
313void acpi_gpiochip_add(struct gpio_chip *chip)
314{
315 acpi_gpiochip_request_interrupts(chip);
316}
317
318void acpi_gpiochip_remove(struct gpio_chip *chip)
319{
320 acpi_gpiochip_free_interrupts(chip);
321}