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_jack_pin *pin;
  64         int enable;
  65         int oldstatus;
  66
  67         if (!jack)
  68                 return;
  69
  70         codec = jack->codec;
  71
  72         mutex_lock(&codec->mutex);
  73
  74         oldstatus = jack->status;
  75
  76         jack->status &= ~mask;
  77         jack->status |= status & mask;
  78
  79         /* The DAPM sync is expensive enough to be worth skipping.
  80          * However, empty mask means pin synchronization is desired. */
  81         if (mask && (jack->status == oldstatus))
  82                 goto out;
  83
  84         list_for_each_entry(pin, &jack->pins, list) {
  85                 enable = pin->mask & jack->status;
  86
  87                 if (pin->invert)
  88                         enable = !enable;
  89
  90                 if (enable)
  91                         snd_soc_dapm_enable_pin(codec, pin->pin);
  92                 else
  93                         snd_soc_dapm_disable_pin(codec, pin->pin);
  94         }
  95
  96         /* Report before the DAPM sync to help users updating micbias status */
  97         blocking_notifier_call_chain(&jack->notifier, status, NULL);
  98
  99         snd_soc_dapm_sync(codec);
 100
 101         snd_jack_report(jack->jack, status);
 102
 103 out:
 104         mutex_unlock(&codec->mutex);
 105 }
 106 EXPORT_SYMBOL_GPL(snd_soc_jack_report);
 107
 108 /**
 109  * snd_soc_jack_add_pins - Associate DAPM pins with an ASoC jack
 110  *
 111  * @jack:  ASoC jack
 112  * @count: Number of pins
 113  * @pins:  Array of pins
 114  *
 115  * After this function has been called the DAPM pins specified in the
 116  * pins array will have their status updated to reflect the current
 117  * state of the jack whenever the jack status is updated.
 118  */
 119 int snd_soc_jack_add_pins(struct snd_soc_jack *jack, int count,
 120                           struct snd_soc_jack_pin *pins)
 121 {
 122         int i;
 123
 124         for (i = 0; i < count; i++) {
 125                 if (!pins[i].pin) {
 126                         printk(KERN_ERR "No name for pin %d\n", i);
 127                         return -EINVAL;
 128                 }
 129                 if (!pins[i].mask) {
 130                         printk(KERN_ERR "No mask for pin %d (%s)\n", i,
 131                                pins[i].pin);
 132                         return -EINVAL;
 133                 }
 134
 135                 INIT_LIST_HEAD(&pins[i].list);
 136                 list_add(&(pins[i].list), &jack->pins);
 137         }
 138
 139         /* Update to reflect the last reported status; canned jack
 140          * implementations are likely to set their state before the
 141          * card has an opportunity to associate pins.
 142          */
 143         snd_soc_jack_report(jack, 0, 0);
 144
 145         return 0;
 146 }
 147 EXPORT_SYMBOL_GPL(snd_soc_jack_add_pins);
 148
 149 /**
 150  * snd_soc_jack_notifier_register - Register a notifier for jack status
 151  *
 152  * @jack:  ASoC jack
 153  * @nb:    Notifier block to register
 154  *
 155  * Register for notification of the current status of the jack.  Note
 156  * that it is not possible to report additional jack events in the
 157  * callback from the notifier, this is intended to support
 158  * applications such as enabling electrical detection only when a
 159  * mechanical detection event has occurred.
 160  */
 161 void snd_soc_jack_notifier_register(struct snd_soc_jack *jack,
 162                                     struct notifier_block *nb)
 163 {
 164         blocking_notifier_chain_register(&jack->notifier, nb);
 165 }
 166 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_register);
 167
 168 /**
 169  * snd_soc_jack_notifier_unregister - Unregister a notifier for jack status
 170  *
 171  * @jack:  ASoC jack
 172  * @nb:    Notifier block to unregister
 173  *
 174  * Stop notifying for status changes.
 175  */
 176 void snd_soc_jack_notifier_unregister(struct snd_soc_jack *jack,
 177                                       struct notifier_block *nb)
 178 {
 179         blocking_notifier_chain_unregister(&jack->notifier, nb);
 180 }
 181 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_unregister);
 182
 183 #ifdef CONFIG_GPIOLIB
 184 /* gpio detect */
 185 static void snd_soc_jack_gpio_detect(struct snd_soc_jack_gpio *gpio)
 186 {
 187         struct snd_soc_jack *jack = gpio->jack;
 188         int enable;
 189         int report;
 190
 191         if (gpio->debounce_time > 0)
 192                 mdelay(gpio->debounce_time);
 193
 194         enable = gpio_get_value(gpio->gpio);
 195         if (gpio->invert)
 196                 enable = !enable;
 197
 198         if (enable)
 199                 report = gpio->report;
 200         else
 201                 report = 0;
 202
 203         if (gpio->jack_status_check)
 204                 report = gpio->jack_status_check();
 205
 206         snd_soc_jack_report(jack, report, gpio->report);
 207 }
 208
 209 /* irq handler for gpio pin */
 210 static irqreturn_t gpio_handler(int irq, void *data)
 211 {
 212         struct snd_soc_jack_gpio *gpio = data;
 213
 214         schedule_work(&gpio->work);
 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);
 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_WORK(&gpios[i].work, gpio_work);
 266                 gpios[i].jack = jack;
 267
 268                 ret = request_irq(gpio_to_irq(gpios[i].gpio),
 269                                 gpio_handler,
 270                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 271                                 jack->codec->dev->driver->name,
 272                                 &gpios[i]);
 273                 if (ret)
 274                         goto err;
 275
 276 #ifdef CONFIG_GPIO_SYSFS
 277                 /* Expose GPIO value over sysfs for diagnostic purposes */
 278                 gpio_export(gpios[i].gpio, false);
 279 #endif
 280
 281                 /* Update initial jack status */
 282                 snd_soc_jack_gpio_detect(&gpios[i]);
 283         }
 284
 285         return 0;
 286
 287 err:
 288         gpio_free(gpios[i].gpio);
 289 undo:
 290         snd_soc_jack_free_gpios(jack, i, gpios);
 291
 292         return ret;
 293 }
 294 EXPORT_SYMBOL_GPL(snd_soc_jack_add_gpios);
 295
 296 /**
 297  * snd_soc_jack_free_gpios - Release GPIO pins' resources of an ASoC jack
 298  *
 299  * @jack:  ASoC jack
 300  * @count: number of pins
 301  * @gpios: array of gpio pins
 302  *
 303  * Release gpio and irq resources for gpio pins associated with an ASoC jack.
 304  */
 305 void snd_soc_jack_free_gpios(struct snd_soc_jack *jack, int count,
 306                         struct snd_soc_jack_gpio *gpios)
 307 {
 308         int i;
 309
 310         for (i = 0; i < count; i++) {
 311 #ifdef CONFIG_GPIO_SYSFS
 312                 gpio_unexport(gpios[i].gpio);
 313 #endif
 314                 free_irq(gpio_to_irq(gpios[i].gpio), &gpios[i]);
 315                 gpio_free(gpios[i].gpio);
 316                 gpios[i].jack = NULL;
 317         }
 318 }
 319 EXPORT_SYMBOL_GPL(snd_soc_jack_free_gpios);
 320 #endif  /* CONFIG_GPIOLIB */