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e29482e8 MN |
1 | /* |
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> | |
936e15dd | 14 | #include <linux/gpio/consumer.h> |
5ccff852 | 15 | #include <linux/gpio/driver.h> |
e29482e8 | 16 | #include <linux/export.h> |
e29482e8 | 17 | #include <linux/acpi.h> |
0d1c28a4 | 18 | #include <linux/interrupt.h> |
e29482e8 | 19 | |
5ccff852 MW |
20 | #include "gpiolib.h" |
21 | ||
7fc7acb9 RW |
22 | struct acpi_gpio_evt_pin { |
23 | struct list_head node; | |
24 | acpi_handle *evt_handle; | |
25 | unsigned int pin; | |
26 | unsigned int irq; | |
27 | }; | |
28 | ||
e29482e8 MN |
29 | static 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 | /** | |
936e15dd | 38 | * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API |
e29482e8 MN |
39 | * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") |
40 | * @pin: ACPI GPIO pin number (0-based, controller-relative) | |
41 | * | |
936e15dd MW |
42 | * Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR |
43 | * error value | |
e29482e8 MN |
44 | */ |
45 | ||
936e15dd | 46 | static struct gpio_desc *acpi_get_gpiod(char *path, int pin) |
e29482e8 MN |
47 | { |
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)) | |
936e15dd | 54 | return ERR_PTR(-ENODEV); |
e29482e8 MN |
55 | |
56 | chip = gpiochip_find(handle, acpi_gpiochip_find); | |
57 | if (!chip) | |
936e15dd | 58 | return ERR_PTR(-ENODEV); |
e29482e8 | 59 | |
936e15dd MW |
60 | if (pin < 0 || pin > chip->ngpio) |
61 | return ERR_PTR(-EINVAL); | |
e29482e8 | 62 | |
390d82e3 | 63 | return gpiochip_get_desc(chip, pin); |
e29482e8 | 64 | } |
0d1c28a4 | 65 | |
0d1c28a4 MN |
66 | static 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 | ||
7fc7acb9 RW |
75 | static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data) |
76 | { | |
77 | struct acpi_gpio_evt_pin *evt_pin = data; | |
7fc7acb9 | 78 | |
524c1081 | 79 | acpi_execute_simple_method(evt_pin->evt_handle, NULL, evt_pin->pin); |
7fc7acb9 RW |
80 | |
81 | return IRQ_HANDLED; | |
82 | } | |
83 | ||
84 | static void acpi_gpio_evt_dh(acpi_handle handle, void *data) | |
85 | { | |
86 | /* The address of this function is used as a key. */ | |
87 | } | |
88 | ||
0d1c28a4 MN |
89 | /** |
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. | |
0d1c28a4 | 98 | */ |
664e3e5a | 99 | static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) |
0d1c28a4 MN |
100 | { |
101 | struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL}; | |
102 | struct acpi_resource *res; | |
7fc7acb9 RW |
103 | acpi_handle handle, evt_handle; |
104 | struct list_head *evt_pins = NULL; | |
0d1c28a4 | 105 | acpi_status status; |
1107ca10 MN |
106 | unsigned int pin; |
107 | int irq, ret; | |
0d1c28a4 MN |
108 | 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 | ||
7fc7acb9 RW |
121 | 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 | } | |
0d1c28a4 | 134 | |
7fc7acb9 RW |
135 | /* |
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 | */ | |
0d1c28a4 MN |
140 | for (res = buf.pointer; |
141 | res && (res->type != ACPI_RESOURCE_TYPE_END_TAG); | |
142 | res = ACPI_NEXT_RESOURCE(res)) { | |
7fc7acb9 RW |
143 | irq_handler_t handler = NULL; |
144 | void *data; | |
0d1c28a4 MN |
145 | |
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 | ||
0d1c28a4 MN |
155 | irq = chip->to_irq(chip, pin); |
156 | if (irq < 0) | |
157 | continue; | |
158 | ||
7fc7acb9 RW |
159 | 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 | ||
0d1c28a4 | 187 | /* Assume BIOS sets the triggering, so no flags */ |
7fc7acb9 RW |
188 | ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler, |
189 | 0, "GPIO-signaled-ACPI-event", | |
190 | data); | |
1107ca10 MN |
191 | if (ret) |
192 | dev_err(chip->dev, | |
193 | "Failed to request IRQ %d ACPI event handler\n", | |
194 | irq); | |
0d1c28a4 MN |
195 | } |
196 | } | |
7fc7acb9 | 197 | |
70b53411 MW |
198 | /** |
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 | */ | |
664e3e5a | 207 | static void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) |
70b53411 MW |
208 | { |
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 | } | |
70b53411 | 234 | |
12028d2d MW |
235 | struct acpi_gpio_lookup { |
236 | struct acpi_gpio_info info; | |
237 | int index; | |
936e15dd | 238 | struct gpio_desc *desc; |
12028d2d MW |
239 | int n; |
240 | }; | |
241 | ||
242 | static 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 | ||
936e15dd | 249 | if (lookup->n++ == lookup->index && !lookup->desc) { |
12028d2d MW |
250 | const struct acpi_resource_gpio *agpio = &ares->data.gpio; |
251 | ||
936e15dd MW |
252 | lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr, |
253 | agpio->pin_table[0]); | |
12028d2d MW |
254 | lookup->info.gpioint = |
255 | agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT; | |
e01f440a MW |
256 | lookup->info.active_low = |
257 | agpio->polarity == ACPI_ACTIVE_LOW; | |
12028d2d MW |
258 | } |
259 | ||
260 | return 1; | |
261 | } | |
262 | ||
263 | /** | |
936e15dd | 264 | * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources |
12028d2d MW |
265 | * @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 | |
936e15dd | 270 | * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor, |
12028d2d MW |
271 | * 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 | * | |
936e15dd | 274 | * If the GPIO cannot be translated or there is an error an ERR_PTR is |
12028d2d MW |
275 | * returned. |
276 | * | |
277 | * Note: if the GPIO resource has multiple entries in the pin list, this | |
278 | * function only returns the first. | |
279 | */ | |
936e15dd MW |
280 | struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index, |
281 | struct acpi_gpio_info *info) | |
12028d2d MW |
282 | { |
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) | |
936e15dd | 290 | return ERR_PTR(-EINVAL); |
12028d2d MW |
291 | |
292 | handle = ACPI_HANDLE(dev); | |
293 | if (!handle || acpi_bus_get_device(handle, &adev)) | |
936e15dd | 294 | return ERR_PTR(-ENODEV); |
12028d2d MW |
295 | |
296 | memset(&lookup, 0, sizeof(lookup)); | |
297 | lookup.index = index; | |
12028d2d MW |
298 | |
299 | INIT_LIST_HEAD(&resource_list); | |
300 | ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio, | |
301 | &lookup); | |
302 | if (ret < 0) | |
936e15dd | 303 | return ERR_PTR(ret); |
12028d2d MW |
304 | |
305 | acpi_dev_free_resource_list(&resource_list); | |
306 | ||
936e15dd | 307 | if (lookup.desc && info) |
12028d2d MW |
308 | *info = lookup.info; |
309 | ||
a00580c2 | 310 | return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT); |
12028d2d | 311 | } |
664e3e5a MW |
312 | |
313 | void acpi_gpiochip_add(struct gpio_chip *chip) | |
314 | { | |
315 | acpi_gpiochip_request_interrupts(chip); | |
316 | } | |
317 | ||
318 | void acpi_gpiochip_remove(struct gpio_chip *chip) | |
319 | { | |
320 | acpi_gpiochip_free_interrupts(chip); | |
321 | } |