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 <sound/soc-dapm.h>
  17 #include <linux/gpio.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/delay.h>
  21
  22 /**
  23  * snd_soc_jack_new - Create a new jack
  24  * @card:  ASoC card
  25  * @id:    an identifying string for this jack
  26  * @type:  a bitmask of enum snd_jack_type values that can be detected by
  27  *         this jack
  28  * @jack:  structure to use for the jack
  29  *
  30  * Creates a new jack object.
  31  *
  32  * Returns zero if successful, or a negative error code on failure.
  33  * On success jack will be initialised.
  34  */
  35 int snd_soc_jack_new(struct snd_soc_codec *codec, const char *id, int type,
  36                      struct snd_soc_jack *jack)
  37 {
  38         jack->codec = codec;
  39         INIT_LIST_HEAD(&jack->pins);
  40         BLOCKING_INIT_NOTIFIER_HEAD(&jack->notifier);
  41
  42         return snd_jack_new(codec->card->snd_card, id, type, &jack->jack);
  43 }
  44 EXPORT_SYMBOL_GPL(snd_soc_jack_new);
  45
  46 /**
  47  * snd_soc_jack_report - Report the current status for a jack
  48  *
  49  * @jack:   the jack
  50  * @status: a bitmask of enum snd_jack_type values that are currently detected.
  51  * @mask:   a bitmask of enum snd_jack_type values that being reported.
  52  *
  53  * If configured using snd_soc_jack_add_pins() then the associated
  54  * DAPM pins will be enabled or disabled as appropriate and DAPM
  55  * synchronised.
  56  *
  57  * Note: This function uses mutexes and should be called from a
  58  * context which can sleep (such as a workqueue).
  59  */
  60 void snd_soc_jack_report(struct snd_soc_jack *jack, int status, int mask)
  61 {
  62         struct snd_soc_codec *codec;
  63         struct snd_soc_dapm_context *dapm;
  64         struct snd_soc_jack_pin *pin;
  65         int enable;
  66         int oldstatus;
  67
  68         if (!jack)
  69                 return;
  70
  71         codec = jack->codec;
  72         dapm =  &codec->dapm;
  73
  74         mutex_lock(&codec->mutex);
  75
  76         oldstatus = jack->status;
  77
  78         jack->status &= ~mask;
  79         jack->status |= status & mask;
  80
  81         /* The DAPM sync is expensive enough to be worth skipping.
  82          * However, empty mask means pin synchronization is desired. */
  83         if (mask && (jack->status == oldstatus))
  84                 goto out;
  85
  86         list_for_each_entry(pin, &jack->pins, list) {
  87                 enable = pin->mask & jack->status;
  88
  89                 if (pin->invert)
  90                         enable = !enable;
  91
  92                 if (enable)
  93                         snd_soc_dapm_enable_pin(dapm, pin->pin);
  94                 else
  95                         snd_soc_dapm_disable_pin(dapm, pin->pin);
  96         }
  97
  98         /* Report before the DAPM sync to help users updating micbias status */
  99         blocking_notifier_call_chain(&jack->notifier, status, NULL);
 100
 101         snd_soc_dapm_sync(dapm);
 102
 103         snd_jack_report(jack->jack, status);
 104
 105 out:
 106         mutex_unlock(&codec->mutex);
 107 }
 108 EXPORT_SYMBOL_GPL(snd_soc_jack_report);
 109
 110 /**
 111  * snd_soc_jack_add_pins - Associate DAPM pins with an ASoC jack
 112  *
 113  * @jack:  ASoC jack
 114  * @count: Number of pins
 115  * @pins:  Array of pins
 116  *
 117  * After this function has been called the DAPM pins specified in the
 118  * pins array will have their status updated to reflect the current
 119  * state of the jack whenever the jack status is updated.
 120  */
 121 int snd_soc_jack_add_pins(struct snd_soc_jack *jack, int count,
 122                           struct snd_soc_jack_pin *pins)
 123 {
 124         int i;
 125
 126         for (i = 0; i < count; i++) {
 127                 if (!pins[i].pin) {
 128                         printk(KERN_ERR "No name for pin %d\n", i);
 129                         return -EINVAL;
 130                 }
 131                 if (!pins[i].mask) {
 132                         printk(KERN_ERR "No mask for pin %d (%s)\n", i,
 133                                pins[i].pin);
 134                         return -EINVAL;
 135                 }
 136
 137                 INIT_LIST_HEAD(&pins[i].list);
 138                 list_add(&(pins[i].list), &jack->pins);
 139         }
 140
 141         /* Update to reflect the last reported status; canned jack
 142          * implementations are likely to set their state before the
 143          * card has an opportunity to associate pins.
 144          */
 145         snd_soc_jack_report(jack, 0, 0);
 146
 147         return 0;
 148 }
 149 EXPORT_SYMBOL_GPL(snd_soc_jack_add_pins);
 150
 151 /**
 152  * snd_soc_jack_notifier_register - Register a notifier for jack status
 153  *
 154  * @jack:  ASoC jack
 155  * @nb:    Notifier block to register
 156  *
 157  * Register for notification of the current status of the jack.  Note
 158  * that it is not possible to report additional jack events in the
 159  * callback from the notifier, this is intended to support
 160  * applications such as enabling electrical detection only when a
 161  * mechanical detection event has occurred.
 162  */
 163 void snd_soc_jack_notifier_register(struct snd_soc_jack *jack,
 164                                     struct notifier_block *nb)
 165 {
 166         blocking_notifier_chain_register(&jack->notifier, nb);
 167 }
 168 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_register);
 169
 170 /**
 171  * snd_soc_jack_notifier_unregister - Unregister a notifier for jack status
 172  *
 173  * @jack:  ASoC jack
 174  * @nb:    Notifier block to unregister
 175  *
 176  * Stop notifying for status changes.
 177  */
 178 void snd_soc_jack_notifier_unregister(struct snd_soc_jack *jack,
 179                                       struct notifier_block *nb)
 180 {
 181         blocking_notifier_chain_unregister(&jack->notifier, nb);
 182 }
 183 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_unregister);
 184
 185 #ifdef CONFIG_GPIOLIB
 186 /* gpio detect */
 187 static void snd_soc_jack_gpio_detect(struct snd_soc_jack_gpio *gpio)
 188 {
 189         struct snd_soc_jack *jack = gpio->jack;
 190         int enable;
 191         int report;
 192
 193         enable = gpio_get_value(gpio->gpio);
 194         if (gpio->invert)
 195                 enable = !enable;
 196
 197         if (enable)
 198                 report = gpio->report;
 199         else
 200                 report = 0;
 201
 202         if (gpio->jack_status_check)
 203                 report = gpio->jack_status_check();
 204
 205         snd_soc_jack_report(jack, report, gpio->report);
 206 }
 207
 208 /* irq handler for gpio pin */
 209 static irqreturn_t gpio_handler(int irq, void *data)
 210 {
 211         struct snd_soc_jack_gpio *gpio = data;
 212
 213         schedule_delayed_work(&gpio->work,
 214                               msecs_to_jiffies(gpio->debounce_time));
 215
 216         return IRQ_HANDLED;
 217 }
 218
 219 /* gpio work */
 220 static void gpio_work(struct work_struct *work)
 221 {
 222         struct snd_soc_jack_gpio *gpio;
 223
 224         gpio = container_of(work, struct snd_soc_jack_gpio, work.work);
 225         snd_soc_jack_gpio_detect(gpio);
 226 }
 227
 228 /**
 229  * snd_soc_jack_add_gpios - Associate GPIO pins with an ASoC jack
 230  *
 231  * @jack:  ASoC jack
 232  * @count: number of pins
 233  * @gpios: array of gpio pins
 234  *
 235  * This function will request gpio, set data direction and request irq
 236  * for each gpio in the array.
 237  */
 238 int snd_soc_jack_add_gpios(struct snd_soc_jack *jack, int count,
 239                         struct snd_soc_jack_gpio *gpios)
 240 {
 241         int i, ret;
 242
 243         for (i = 0; i < count; i++) {
 244                 if (!gpio_is_valid(gpios[i].gpio)) {
 245                         printk(KERN_ERR "Invalid gpio %d\n",
 246                                 gpios[i].gpio);
 247                         ret = -EINVAL;
 248                         goto undo;
 249                 }
 250                 if (!gpios[i].name) {
 251                         printk(KERN_ERR "No name for gpio %d\n",
 252                                 gpios[i].gpio);
 253                         ret = -EINVAL;
 254                         goto undo;
 255                 }
 256
 257                 ret = gpio_request(gpios[i].gpio, gpios[i].name);
 258                 if (ret)
 259                         goto undo;
 260
 261                 ret = gpio_direction_input(gpios[i].gpio);
 262                 if (ret)
 263                         goto err;
 264
 265                 INIT_DELAYED_WORK(&gpios[i].work, gpio_work);
 266                 gpios[i].jack = jack;
 267
 268                 ret = request_any_context_irq(gpio_to_irq(gpios[i].gpio),
 269                                               gpio_handler,
 270                                               IRQF_TRIGGER_RISING |
 271                                               IRQF_TRIGGER_FALLING,
 272                                               jack->codec->dev->driver->name,
 273                                               &gpios[i]);
 274                 if (ret)
 275                         goto err;
 276
 277 #ifdef CONFIG_GPIO_SYSFS
 278                 /* Expose GPIO value over sysfs for diagnostic purposes */
 279                 gpio_export(gpios[i].gpio, false);
 280 #endif
 281
 282                 /* Update initial jack status */
 283                 snd_soc_jack_gpio_detect(&gpios[i]);
 284         }
 285
 286         return 0;
 287
 288 err:
 289         gpio_free(gpios[i].gpio);
 290 undo:
 291         snd_soc_jack_free_gpios(jack, i, gpios);
 292
 293         return ret;
 294 }
 295 EXPORT_SYMBOL_GPL(snd_soc_jack_add_gpios);
 296
 297 /**
 298  * snd_soc_jack_free_gpios - Release GPIO pins' resources of an ASoC jack
 299  *
 300  * @jack:  ASoC jack
 301  * @count: number of pins
 302  * @gpios: array of gpio pins
 303  *
 304  * Release gpio and irq resources for gpio pins associated with an ASoC jack.
 305  */
 306 void snd_soc_jack_free_gpios(struct snd_soc_jack *jack, int count,
 307                         struct snd_soc_jack_gpio *gpios)
 308 {
 309         int i;
 310
 311         for (i = 0; i < count; i++) {
 312 #ifdef CONFIG_GPIO_SYSFS
 313                 gpio_unexport(gpios[i].gpio);
 314 #endif
 315                 free_irq(gpio_to_irq(gpios[i].gpio), &gpios[i]);
 316                 cancel_delayed_work_sync(&gpios[i].work);
 317                 gpio_free(gpios[i].gpio);
 318                 gpios[i].jack = NULL;
 319         }
 320 }
 321 EXPORT_SYMBOL_GPL(snd_soc_jack_free_gpios);
 322 #endif  /* CONFIG_GPIOLIB */