ALSA: timer: fix NULL pointer dereference in read()/ioctl() race
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / sound / soc / soc-jack.c
1 /*
2 * soc-jack.c -- ALSA SoC jack handling
3 *
4 * Copyright 2008 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 */
13
14 #include <sound/jack.h>
15 #include <sound/soc.h>
16 #include <linux/gpio.h>
17 #include <linux/interrupt.h>
18 #include <linux/workqueue.h>
19 #include <linux/delay.h>
20 #include <linux/export.h>
21 #include <trace/events/asoc.h>
22
23 /**
24 * snd_soc_jack_new - Create a new jack
25 * @codec: ASoC codec
26 * @id: an identifying string for this jack
27 * @type: a bitmask of enum snd_jack_type values that can be detected by
28 * this jack
29 * @jack: structure to use for the jack
30 *
31 * Creates a new jack object.
32 *
33 * Returns zero if successful, or a negative error code on failure.
34 * On success jack will be initialised.
35 */
36 int snd_soc_jack_new(struct snd_soc_codec *codec, const char *id, int type,
37 struct snd_soc_jack *jack)
38 {
39 mutex_init(&jack->mutex);
40 jack->codec = codec;
41 INIT_LIST_HEAD(&jack->pins);
42 INIT_LIST_HEAD(&jack->jack_zones);
43 BLOCKING_INIT_NOTIFIER_HEAD(&jack->notifier);
44
45 return snd_jack_new(codec->card->snd_card, id, type, &jack->jack);
46 }
47 EXPORT_SYMBOL_GPL(snd_soc_jack_new);
48
49 /**
50 * snd_soc_jack_report - Report the current status for a jack
51 *
52 * @jack: the jack
53 * @status: a bitmask of enum snd_jack_type values that are currently detected.
54 * @mask: a bitmask of enum snd_jack_type values that being reported.
55 *
56 * If configured using snd_soc_jack_add_pins() then the associated
57 * DAPM pins will be enabled or disabled as appropriate and DAPM
58 * synchronised.
59 *
60 * Note: This function uses mutexes and should be called from a
61 * context which can sleep (such as a workqueue).
62 */
63 void snd_soc_jack_report(struct snd_soc_jack *jack, int status, int mask)
64 {
65 struct snd_soc_codec *codec;
66 struct snd_soc_dapm_context *dapm;
67 struct snd_soc_jack_pin *pin;
68 int enable;
69
70 trace_snd_soc_jack_report(jack, mask, status);
71
72 if (!jack)
73 return;
74
75 codec = jack->codec;
76 dapm = &codec->dapm;
77
78 mutex_lock(&jack->mutex);
79
80 jack->status &= ~mask;
81 jack->status |= status & mask;
82
83 trace_snd_soc_jack_notify(jack, status);
84
85 list_for_each_entry(pin, &jack->pins, list) {
86 enable = pin->mask & jack->status;
87
88 if (pin->invert)
89 enable = !enable;
90
91 if (enable)
92 snd_soc_dapm_enable_pin(dapm, pin->pin);
93 else
94 snd_soc_dapm_disable_pin(dapm, pin->pin);
95 }
96
97 /* Report before the DAPM sync to help users updating micbias status */
98 blocking_notifier_call_chain(&jack->notifier, jack->status, jack);
99
100 snd_soc_dapm_sync(dapm);
101
102 snd_jack_report(jack->jack, jack->status);
103
104 mutex_unlock(&jack->mutex);
105 }
106 EXPORT_SYMBOL_GPL(snd_soc_jack_report);
107
108 /**
109 * snd_soc_jack_add_zones - Associate voltage zones with jack
110 *
111 * @jack: ASoC jack
112 * @count: Number of zones
113 * @zone: Array of zones
114 *
115 * After this function has been called the zones specified in the
116 * array will be associated with the jack.
117 */
118 int snd_soc_jack_add_zones(struct snd_soc_jack *jack, int count,
119 struct snd_soc_jack_zone *zones)
120 {
121 int i;
122
123 for (i = 0; i < count; i++) {
124 INIT_LIST_HEAD(&zones[i].list);
125 list_add(&(zones[i].list), &jack->jack_zones);
126 }
127 return 0;
128 }
129 EXPORT_SYMBOL_GPL(snd_soc_jack_add_zones);
130
131 /**
132 * snd_soc_jack_get_type - Based on the mic bias value, this function returns
133 * the type of jack from the zones declared in the jack type
134 *
135 * @jack: ASoC jack
136 * @micbias_voltage: mic bias voltage at adc channel when jack is plugged in
137 *
138 * Based on the mic bias value passed, this function helps identify
139 * the type of jack from the already declared jack zones
140 */
141 int snd_soc_jack_get_type(struct snd_soc_jack *jack, int micbias_voltage)
142 {
143 struct snd_soc_jack_zone *zone;
144
145 list_for_each_entry(zone, &jack->jack_zones, list) {
146 if (micbias_voltage >= zone->min_mv &&
147 micbias_voltage < zone->max_mv)
148 return zone->jack_type;
149 }
150 return 0;
151 }
152 EXPORT_SYMBOL_GPL(snd_soc_jack_get_type);
153
154 /**
155 * snd_soc_jack_add_pins - Associate DAPM pins with an ASoC jack
156 *
157 * @jack: ASoC jack
158 * @count: Number of pins
159 * @pins: Array of pins
160 *
161 * After this function has been called the DAPM pins specified in the
162 * pins array will have their status updated to reflect the current
163 * state of the jack whenever the jack status is updated.
164 */
165 int snd_soc_jack_add_pins(struct snd_soc_jack *jack, int count,
166 struct snd_soc_jack_pin *pins)
167 {
168 int i;
169
170 for (i = 0; i < count; i++) {
171 if (!pins[i].pin) {
172 dev_err(jack->codec->dev, "ASoC: No name for pin %d\n",
173 i);
174 return -EINVAL;
175 }
176 if (!pins[i].mask) {
177 dev_err(jack->codec->dev, "ASoC: No mask for pin %d"
178 " (%s)\n", i, pins[i].pin);
179 return -EINVAL;
180 }
181
182 INIT_LIST_HEAD(&pins[i].list);
183 list_add(&(pins[i].list), &jack->pins);
184 }
185
186 snd_soc_dapm_new_widgets(&jack->codec->card->dapm);
187
188 /* Update to reflect the last reported status; canned jack
189 * implementations are likely to set their state before the
190 * card has an opportunity to associate pins.
191 */
192 snd_soc_jack_report(jack, 0, 0);
193
194 return 0;
195 }
196 EXPORT_SYMBOL_GPL(snd_soc_jack_add_pins);
197
198 /**
199 * snd_soc_jack_notifier_register - Register a notifier for jack status
200 *
201 * @jack: ASoC jack
202 * @nb: Notifier block to register
203 *
204 * Register for notification of the current status of the jack. Note
205 * that it is not possible to report additional jack events in the
206 * callback from the notifier, this is intended to support
207 * applications such as enabling electrical detection only when a
208 * mechanical detection event has occurred.
209 */
210 void snd_soc_jack_notifier_register(struct snd_soc_jack *jack,
211 struct notifier_block *nb)
212 {
213 blocking_notifier_chain_register(&jack->notifier, nb);
214 }
215 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_register);
216
217 /**
218 * snd_soc_jack_notifier_unregister - Unregister a notifier for jack status
219 *
220 * @jack: ASoC jack
221 * @nb: Notifier block to unregister
222 *
223 * Stop notifying for status changes.
224 */
225 void snd_soc_jack_notifier_unregister(struct snd_soc_jack *jack,
226 struct notifier_block *nb)
227 {
228 blocking_notifier_chain_unregister(&jack->notifier, nb);
229 }
230 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_unregister);
231
232 #ifdef CONFIG_GPIOLIB
233 /* gpio detect */
234 static void snd_soc_jack_gpio_detect(struct snd_soc_jack_gpio *gpio)
235 {
236 struct snd_soc_jack *jack = gpio->jack;
237 int enable;
238 int report;
239
240 enable = gpio_get_value_cansleep(gpio->gpio);
241 if (gpio->invert)
242 enable = !enable;
243
244 if (enable)
245 report = gpio->report;
246 else
247 report = 0;
248
249 if (gpio->jack_status_check)
250 report = gpio->jack_status_check();
251
252 snd_soc_jack_report(jack, report, gpio->report);
253 }
254
255 /* irq handler for gpio pin */
256 static irqreturn_t gpio_handler(int irq, void *data)
257 {
258 struct snd_soc_jack_gpio *gpio = data;
259 struct device *dev = gpio->jack->codec->card->dev;
260
261 trace_snd_soc_jack_irq(gpio->name);
262
263 if (device_may_wakeup(dev))
264 pm_wakeup_event(dev, gpio->debounce_time + 50);
265
266 schedule_delayed_work(&gpio->work,
267 msecs_to_jiffies(gpio->debounce_time));
268
269 return IRQ_HANDLED;
270 }
271
272 /* gpio work */
273 static void gpio_work(struct work_struct *work)
274 {
275 struct snd_soc_jack_gpio *gpio;
276
277 gpio = container_of(work, struct snd_soc_jack_gpio, work.work);
278 snd_soc_jack_gpio_detect(gpio);
279 }
280
281 /**
282 * snd_soc_jack_add_gpios - Associate GPIO pins with an ASoC jack
283 *
284 * @jack: ASoC jack
285 * @count: number of pins
286 * @gpios: array of gpio pins
287 *
288 * This function will request gpio, set data direction and request irq
289 * for each gpio in the array.
290 */
291 int snd_soc_jack_add_gpios(struct snd_soc_jack *jack, int count,
292 struct snd_soc_jack_gpio *gpios)
293 {
294 int i, ret;
295
296 for (i = 0; i < count; i++) {
297 if (!gpio_is_valid(gpios[i].gpio)) {
298 dev_err(jack->codec->dev, "ASoC: Invalid gpio %d\n",
299 gpios[i].gpio);
300 ret = -EINVAL;
301 goto undo;
302 }
303 if (!gpios[i].name) {
304 dev_err(jack->codec->dev, "ASoC: No name for gpio %d\n",
305 gpios[i].gpio);
306 ret = -EINVAL;
307 goto undo;
308 }
309
310 ret = gpio_request(gpios[i].gpio, gpios[i].name);
311 if (ret)
312 goto undo;
313
314 ret = gpio_direction_input(gpios[i].gpio);
315 if (ret)
316 goto err;
317
318 INIT_DELAYED_WORK(&gpios[i].work, gpio_work);
319 gpios[i].jack = jack;
320
321 ret = request_any_context_irq(gpio_to_irq(gpios[i].gpio),
322 gpio_handler,
323 IRQF_TRIGGER_RISING |
324 IRQF_TRIGGER_FALLING,
325 gpios[i].name,
326 &gpios[i]);
327 if (ret < 0)
328 goto err;
329
330 if (gpios[i].wake) {
331 ret = irq_set_irq_wake(gpio_to_irq(gpios[i].gpio), 1);
332 if (ret != 0)
333 dev_err(jack->codec->dev, "ASoC: "
334 "Failed to mark GPIO %d as wake source: %d\n",
335 gpios[i].gpio, ret);
336 }
337
338 /* Expose GPIO value over sysfs for diagnostic purposes */
339 gpio_export(gpios[i].gpio, false);
340
341 /* Update initial jack status */
342 snd_soc_jack_gpio_detect(&gpios[i]);
343 }
344
345 return 0;
346
347 err:
348 gpio_free(gpios[i].gpio);
349 undo:
350 snd_soc_jack_free_gpios(jack, i, gpios);
351
352 return ret;
353 }
354 EXPORT_SYMBOL_GPL(snd_soc_jack_add_gpios);
355
356 /**
357 * snd_soc_jack_free_gpios - Release GPIO pins' resources of an ASoC jack
358 *
359 * @jack: ASoC jack
360 * @count: number of pins
361 * @gpios: array of gpio pins
362 *
363 * Release gpio and irq resources for gpio pins associated with an ASoC jack.
364 */
365 void snd_soc_jack_free_gpios(struct snd_soc_jack *jack, int count,
366 struct snd_soc_jack_gpio *gpios)
367 {
368 int i;
369
370 for (i = 0; i < count; i++) {
371 gpio_unexport(gpios[i].gpio);
372 free_irq(gpio_to_irq(gpios[i].gpio), &gpios[i]);
373 cancel_delayed_work_sync(&gpios[i].work);
374 gpio_free(gpios[i].gpio);
375 gpios[i].jack = NULL;
376 }
377 }
378 EXPORT_SYMBOL_GPL(snd_soc_jack_free_gpios);
379 #endif /* CONFIG_GPIOLIB */