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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> | |
14 | #include <linux/gpio.h> | |
15 | #include <linux/export.h> | |
16 | #include <linux/acpi_gpio.h> | |
17 | #include <linux/acpi.h> | |
0d1c28a4 | 18 | #include <linux/interrupt.h> |
e29482e8 | 19 | |
7fc7acb9 RW |
20 | struct acpi_gpio_evt_pin { |
21 | struct list_head node; | |
22 | acpi_handle *evt_handle; | |
23 | unsigned int pin; | |
24 | unsigned int irq; | |
25 | }; | |
26 | ||
e29482e8 MN |
27 | static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) |
28 | { | |
29 | if (!gc->dev) | |
30 | return false; | |
31 | ||
32 | return ACPI_HANDLE(gc->dev) == data; | |
33 | } | |
34 | ||
35 | /** | |
36 | * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API | |
37 | * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") | |
38 | * @pin: ACPI GPIO pin number (0-based, controller-relative) | |
39 | * | |
40 | * Returns GPIO number to use with Linux generic GPIO API, or errno error value | |
41 | */ | |
42 | ||
43 | int acpi_get_gpio(char *path, int pin) | |
44 | { | |
45 | struct gpio_chip *chip; | |
46 | acpi_handle handle; | |
47 | acpi_status status; | |
48 | ||
49 | status = acpi_get_handle(NULL, path, &handle); | |
50 | if (ACPI_FAILURE(status)) | |
51 | return -ENODEV; | |
52 | ||
53 | chip = gpiochip_find(handle, acpi_gpiochip_find); | |
54 | if (!chip) | |
55 | return -ENODEV; | |
56 | ||
57 | if (!gpio_is_valid(chip->base + pin)) | |
58 | return -EINVAL; | |
59 | ||
60 | return chip->base + pin; | |
61 | } | |
62 | EXPORT_SYMBOL_GPL(acpi_get_gpio); | |
0d1c28a4 | 63 | |
0d1c28a4 MN |
64 | static irqreturn_t acpi_gpio_irq_handler(int irq, void *data) |
65 | { | |
66 | acpi_handle handle = data; | |
67 | ||
68 | acpi_evaluate_object(handle, NULL, NULL, NULL); | |
69 | ||
70 | return IRQ_HANDLED; | |
71 | } | |
72 | ||
7fc7acb9 RW |
73 | static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data) |
74 | { | |
75 | struct acpi_gpio_evt_pin *evt_pin = data; | |
7fc7acb9 | 76 | |
524c1081 | 77 | acpi_execute_simple_method(evt_pin->evt_handle, NULL, evt_pin->pin); |
7fc7acb9 RW |
78 | |
79 | return IRQ_HANDLED; | |
80 | } | |
81 | ||
82 | static void acpi_gpio_evt_dh(acpi_handle handle, void *data) | |
83 | { | |
84 | /* The address of this function is used as a key. */ | |
85 | } | |
86 | ||
0d1c28a4 MN |
87 | /** |
88 | * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events | |
89 | * @chip: gpio chip | |
90 | * | |
91 | * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are | |
92 | * handled by ACPI event methods which need to be called from the GPIO | |
93 | * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which | |
94 | * gpio pins have acpi event methods and assigns interrupt handlers that calls | |
95 | * the acpi event methods for those pins. | |
0d1c28a4 | 96 | */ |
0d1c28a4 MN |
97 | void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) |
98 | { | |
99 | struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL}; | |
100 | struct acpi_resource *res; | |
7fc7acb9 RW |
101 | acpi_handle handle, evt_handle; |
102 | struct list_head *evt_pins = NULL; | |
0d1c28a4 | 103 | acpi_status status; |
1107ca10 MN |
104 | unsigned int pin; |
105 | int irq, ret; | |
0d1c28a4 MN |
106 | char ev_name[5]; |
107 | ||
108 | if (!chip->dev || !chip->to_irq) | |
109 | return; | |
110 | ||
111 | handle = ACPI_HANDLE(chip->dev); | |
112 | if (!handle) | |
113 | return; | |
114 | ||
115 | status = acpi_get_event_resources(handle, &buf); | |
116 | if (ACPI_FAILURE(status)) | |
117 | return; | |
118 | ||
7fc7acb9 RW |
119 | status = acpi_get_handle(handle, "_EVT", &evt_handle); |
120 | if (ACPI_SUCCESS(status)) { | |
121 | evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL); | |
122 | if (evt_pins) { | |
123 | INIT_LIST_HEAD(evt_pins); | |
124 | status = acpi_attach_data(handle, acpi_gpio_evt_dh, | |
125 | evt_pins); | |
126 | if (ACPI_FAILURE(status)) { | |
127 | kfree(evt_pins); | |
128 | evt_pins = NULL; | |
129 | } | |
130 | } | |
131 | } | |
0d1c28a4 | 132 | |
7fc7acb9 RW |
133 | /* |
134 | * If a GPIO interrupt has an ACPI event handler method, or _EVT is | |
135 | * present, set up an interrupt handler that calls the ACPI event | |
136 | * handler. | |
137 | */ | |
0d1c28a4 MN |
138 | for (res = buf.pointer; |
139 | res && (res->type != ACPI_RESOURCE_TYPE_END_TAG); | |
140 | res = ACPI_NEXT_RESOURCE(res)) { | |
7fc7acb9 RW |
141 | irq_handler_t handler = NULL; |
142 | void *data; | |
0d1c28a4 MN |
143 | |
144 | if (res->type != ACPI_RESOURCE_TYPE_GPIO || | |
145 | res->data.gpio.connection_type != | |
146 | ACPI_RESOURCE_GPIO_TYPE_INT) | |
147 | continue; | |
148 | ||
149 | pin = res->data.gpio.pin_table[0]; | |
150 | if (pin > chip->ngpio) | |
151 | continue; | |
152 | ||
0d1c28a4 MN |
153 | irq = chip->to_irq(chip, pin); |
154 | if (irq < 0) | |
155 | continue; | |
156 | ||
7fc7acb9 RW |
157 | if (pin <= 255) { |
158 | acpi_handle ev_handle; | |
159 | ||
160 | sprintf(ev_name, "_%c%02X", | |
161 | res->data.gpio.triggering ? 'E' : 'L', pin); | |
162 | status = acpi_get_handle(handle, ev_name, &ev_handle); | |
163 | if (ACPI_SUCCESS(status)) { | |
164 | handler = acpi_gpio_irq_handler; | |
165 | data = ev_handle; | |
166 | } | |
167 | } | |
168 | if (!handler && evt_pins) { | |
169 | struct acpi_gpio_evt_pin *evt_pin; | |
170 | ||
171 | evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL); | |
172 | if (!evt_pin) | |
173 | continue; | |
174 | ||
175 | list_add_tail(&evt_pin->node, evt_pins); | |
176 | evt_pin->evt_handle = evt_handle; | |
177 | evt_pin->pin = pin; | |
178 | evt_pin->irq = irq; | |
179 | handler = acpi_gpio_irq_handler_evt; | |
180 | data = evt_pin; | |
181 | } | |
182 | if (!handler) | |
183 | continue; | |
184 | ||
0d1c28a4 | 185 | /* Assume BIOS sets the triggering, so no flags */ |
7fc7acb9 RW |
186 | ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler, |
187 | 0, "GPIO-signaled-ACPI-event", | |
188 | data); | |
1107ca10 MN |
189 | if (ret) |
190 | dev_err(chip->dev, | |
191 | "Failed to request IRQ %d ACPI event handler\n", | |
192 | irq); | |
0d1c28a4 MN |
193 | } |
194 | } | |
195 | EXPORT_SYMBOL(acpi_gpiochip_request_interrupts); | |
7fc7acb9 | 196 | |
70b53411 MW |
197 | /** |
198 | * acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts. | |
199 | * @chip: gpio chip | |
200 | * | |
201 | * Free interrupts associated with the _EVT method for the given GPIO chip. | |
202 | * | |
203 | * The remaining ACPI event interrupts associated with the chip are freed | |
204 | * automatically. | |
205 | */ | |
206 | void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) | |
207 | { | |
208 | acpi_handle handle; | |
209 | acpi_status status; | |
210 | struct list_head *evt_pins; | |
211 | struct acpi_gpio_evt_pin *evt_pin, *ep; | |
212 | ||
213 | if (!chip->dev || !chip->to_irq) | |
214 | return; | |
215 | ||
216 | handle = ACPI_HANDLE(chip->dev); | |
217 | if (!handle) | |
218 | return; | |
219 | ||
220 | status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins); | |
221 | if (ACPI_FAILURE(status)) | |
222 | return; | |
223 | ||
224 | list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) { | |
225 | devm_free_irq(chip->dev, evt_pin->irq, evt_pin); | |
226 | list_del(&evt_pin->node); | |
227 | kfree(evt_pin); | |
228 | } | |
229 | ||
230 | acpi_detach_data(handle, acpi_gpio_evt_dh); | |
231 | kfree(evt_pins); | |
232 | } | |
233 | EXPORT_SYMBOL(acpi_gpiochip_free_interrupts); | |
234 | ||
12028d2d MW |
235 | struct acpi_gpio_lookup { |
236 | struct acpi_gpio_info info; | |
237 | int index; | |
238 | int gpio; | |
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 | ||
249 | if (lookup->n++ == lookup->index && lookup->gpio < 0) { | |
250 | const struct acpi_resource_gpio *agpio = &ares->data.gpio; | |
251 | ||
252 | lookup->gpio = acpi_get_gpio(agpio->resource_source.string_ptr, | |
253 | agpio->pin_table[0]); | |
254 | lookup->info.gpioint = | |
255 | agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT; | |
256 | } | |
257 | ||
258 | return 1; | |
259 | } | |
260 | ||
261 | /** | |
262 | * acpi_get_gpio_by_index() - get a GPIO number from device resources | |
263 | * @dev: pointer to a device to get GPIO from | |
264 | * @index: index of GpioIo/GpioInt resource (starting from %0) | |
265 | * @info: info pointer to fill in (optional) | |
266 | * | |
267 | * Function goes through ACPI resources for @dev and based on @index looks | |
268 | * up a GpioIo/GpioInt resource, translates it to the Linux GPIO number, | |
269 | * and returns it. @index matches GpioIo/GpioInt resources only so if there | |
270 | * are total %3 GPIO resources, the index goes from %0 to %2. | |
271 | * | |
272 | * If the GPIO cannot be translated or there is an error, negative errno is | |
273 | * returned. | |
274 | * | |
275 | * Note: if the GPIO resource has multiple entries in the pin list, this | |
276 | * function only returns the first. | |
277 | */ | |
278 | int acpi_get_gpio_by_index(struct device *dev, int index, | |
279 | struct acpi_gpio_info *info) | |
280 | { | |
281 | struct acpi_gpio_lookup lookup; | |
282 | struct list_head resource_list; | |
283 | struct acpi_device *adev; | |
284 | acpi_handle handle; | |
285 | int ret; | |
286 | ||
287 | if (!dev) | |
288 | return -EINVAL; | |
289 | ||
290 | handle = ACPI_HANDLE(dev); | |
291 | if (!handle || acpi_bus_get_device(handle, &adev)) | |
292 | return -ENODEV; | |
293 | ||
294 | memset(&lookup, 0, sizeof(lookup)); | |
295 | lookup.index = index; | |
296 | lookup.gpio = -ENODEV; | |
297 | ||
298 | INIT_LIST_HEAD(&resource_list); | |
299 | ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio, | |
300 | &lookup); | |
301 | if (ret < 0) | |
302 | return ret; | |
303 | ||
304 | acpi_dev_free_resource_list(&resource_list); | |
305 | ||
306 | if (lookup.gpio >= 0 && info) | |
307 | *info = lookup.info; | |
308 | ||
309 | return lookup.gpio; | |
310 | } | |
311 | EXPORT_SYMBOL_GPL(acpi_get_gpio_by_index); |