sound/soc/soc-jack.c - kernel/msm - Gitiles

 /*
  * soc-jack.c  --  ALSA SoC jack handling
  *
  * Copyright 2008 Wolfson Microelectronics PLC.
  *
  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  *
  *  This program is free software; you can redistribute  it and/or modify it
  *  under  the terms of  the GNU General  Public License as published by the
  *  Free Software Foundation;  either version 2 of the  License, or (at your
  *  option) any later version.
  */

 #include <sound/jack.h>
 #include <sound/soc.h>
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/workqueue.h>
 #include <linux/delay.h>
 #include <trace/events/asoc.h>

 /**
  * snd_soc_jack_new - Create a new jack
  * @card:  ASoC card
  * @id:    an identifying string for this jack
  * @type:  a bitmask of enum snd_jack_type values that can be detected by
  *         this jack
  * @jack:  structure to use for the jack
  *
  * Creates a new jack object.
  *
  * Returns zero if successful, or a negative error code on failure.
  * On success jack will be initialised.
  */
 int snd_soc_jack_new(struct snd_soc_codec *codec, const char *id, int type,
 		     struct snd_soc_jack *jack)
 {
 	jack->codec = codec;
 	INIT_LIST_HEAD(&jack->pins);
 	INIT_LIST_HEAD(&jack->jack_zones);
 	BLOCKING_INIT_NOTIFIER_HEAD(&jack->notifier);

 	return snd_jack_new(codec->card->snd_card, id, type, &jack->jack);
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_new);

 /**
  * snd_soc_jack_report - Report the current status for a jack
  *
  * @jack:   the jack
  * @status: a bitmask of enum snd_jack_type values that are currently detected.
  * @mask:   a bitmask of enum snd_jack_type values that being reported.
  *
  * If configured using snd_soc_jack_add_pins() then the associated
  * DAPM pins will be enabled or disabled as appropriate and DAPM
  * synchronised.
  *
  * Note: This function uses mutexes and should be called from a
  * context which can sleep (such as a workqueue).
  */
 void snd_soc_jack_report(struct snd_soc_jack *jack, int status, int mask)
 {
 	struct snd_soc_codec *codec;
 	struct snd_soc_dapm_context *dapm;
 	struct snd_soc_jack_pin *pin;
 	int enable;
 	int oldstatus;

 	trace_snd_soc_jack_report(jack, mask, status);

 	if (!jack)
 		return;

 	codec = jack->codec;
 	dapm =  &codec->dapm;

 	mutex_lock(&codec->mutex);

 	oldstatus = jack->status;

 	jack->status &= ~mask;
 	jack->status |= status & mask;

 	/* The DAPM sync is expensive enough to be worth skipping.
 	 * However, empty mask means pin synchronization is desired. */
 	if (mask && (jack->status == oldstatus))
 		goto out;

 	trace_snd_soc_jack_notify(jack, status);

 	list_for_each_entry(pin, &jack->pins, list) {
 		enable = pin->mask & jack->status;

 		if (pin->invert)
 			enable = !enable;

 		if (enable)
 			snd_soc_dapm_enable_pin(dapm, pin->pin);
 		else
 			snd_soc_dapm_disable_pin(dapm, pin->pin);
 	}

 	/* Report before the DAPM sync to help users updating micbias status */
 	blocking_notifier_call_chain(&jack->notifier, status, jack);

 	snd_soc_dapm_sync(dapm);

 	snd_jack_report(jack->jack, jack->status);

 out:
 	mutex_unlock(&codec->mutex);
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_report);

 /**
  * snd_soc_jack_report_no_dapm - Report the current status for a jack
  *				 without DAPM sync
  * @jack:   the jack
  * @status: a bitmask of enum snd_jack_type values that are currently detected.
  * @mask:   a bitmask of enum snd_jack_type values that being reported.
  */
 void snd_soc_jack_report_no_dapm(struct snd_soc_jack *jack, int status,
 				 int mask)
 {
 	jack->status &= ~mask;
 	jack->status |= status & mask;

 	snd_jack_report(jack->jack, jack->status);
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_report_no_dapm);

 /**
  * snd_soc_jack_add_zones - Associate voltage zones with jack
  *
  * @jack:  ASoC jack
  * @count: Number of zones
  * @zone:  Array of zones
  *
  * After this function has been called the zones specified in the
  * array will be associated with the jack.
  */
 int snd_soc_jack_add_zones(struct snd_soc_jack *jack, int count,
 			  struct snd_soc_jack_zone *zones)
 {
 	int i;

 	for (i = 0; i < count; i++) {
 		INIT_LIST_HEAD(&zones[i].list);
 		list_add(&(zones[i].list), &jack->jack_zones);
 	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_add_zones);

 /**
  * snd_soc_jack_get_type - Based on the mic bias value, this function returns
  * the type of jack from the zones delcared in the jack type
  *
  * @micbias_voltage:  mic bias voltage at adc channel when jack is plugged in
  *
  * Based on the mic bias value passed, this function helps identify
  * the type of jack from the already delcared jack zones
  */
 int snd_soc_jack_get_type(struct snd_soc_jack *jack, int micbias_voltage)
 {
 	struct snd_soc_jack_zone *zone;

 	list_for_each_entry(zone, &jack->jack_zones, list) {
 		if (micbias_voltage >= zone->min_mv &&
 			micbias_voltage < zone->max_mv)
 				return zone->jack_type;
 	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_get_type);

 /**
  * snd_soc_jack_add_pins - Associate DAPM pins with an ASoC jack
  *
  * @jack:  ASoC jack
  * @count: Number of pins
  * @pins:  Array of pins
  *
  * After this function has been called the DAPM pins specified in the
  * pins array will have their status updated to reflect the current
  * state of the jack whenever the jack status is updated.
  */
 int snd_soc_jack_add_pins(struct snd_soc_jack *jack, int count,
 			  struct snd_soc_jack_pin *pins)
 {
 	int i;

 	for (i = 0; i < count; i++) {
 		if (!pins[i].pin) {
 			printk(KERN_ERR "No name for pin %d\n", i);
 			return -EINVAL;
 		}
 		if (!pins[i].mask) {
 			printk(KERN_ERR "No mask for pin %d (%s)\n", i,
 			       pins[i].pin);
 			return -EINVAL;
 		}

 		INIT_LIST_HEAD(&pins[i].list);
 		list_add(&(pins[i].list), &jack->pins);
 	}

 	/* Update to reflect the last reported status; canned jack
 	 * implementations are likely to set their state before the
 	 * card has an opportunity to associate pins.
 	 */
 	snd_soc_jack_report(jack, 0, 0);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_add_pins);

 /**
  * snd_soc_jack_notifier_register - Register a notifier for jack status
  *
  * @jack:  ASoC jack
  * @nb:    Notifier block to register
  *
  * Register for notification of the current status of the jack.  Note
  * that it is not possible to report additional jack events in the
  * callback from the notifier, this is intended to support
  * applications such as enabling electrical detection only when a
  * mechanical detection event has occurred.
  */
 void snd_soc_jack_notifier_register(struct snd_soc_jack *jack,
 				    struct notifier_block *nb)
 {
 	blocking_notifier_chain_register(&jack->notifier, nb);
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_register);

 /**
  * snd_soc_jack_notifier_unregister - Unregister a notifier for jack status
  *
  * @jack:  ASoC jack
  * @nb:    Notifier block to unregister
  *
  * Stop notifying for status changes.
  */
 void snd_soc_jack_notifier_unregister(struct snd_soc_jack *jack,
 				      struct notifier_block *nb)
 {
 	blocking_notifier_chain_unregister(&jack->notifier, nb);
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_unregister);

 #ifdef CONFIG_GPIOLIB
 /* gpio detect */
 static void snd_soc_jack_gpio_detect(struct snd_soc_jack_gpio *gpio)
 {
 	struct snd_soc_jack *jack = gpio->jack;
 	int enable;
 	int report;

 	enable = gpio_get_value_cansleep(gpio->gpio);
 	if (gpio->invert)
 		enable = !enable;

 	if (enable)
 		report = gpio->report;
 	else
 		report = 0;

 	if (gpio->jack_status_check)
 		report = gpio->jack_status_check();

 	snd_soc_jack_report(jack, report, gpio->report);
 }

 /* irq handler for gpio pin */
 static irqreturn_t gpio_handler(int irq, void *data)
 {
 	struct snd_soc_jack_gpio *gpio = data;
 	struct device *dev = gpio->jack->codec->card->dev;

 	trace_snd_soc_jack_irq(gpio->name);

 	if (device_may_wakeup(dev))
 		pm_wakeup_event(dev, gpio->debounce_time + 50);

 	schedule_delayed_work(&gpio->work,
 			      msecs_to_jiffies(gpio->debounce_time));

 	return IRQ_HANDLED;
 }

 /* gpio work */
 static void gpio_work(struct work_struct *work)
 {
 	struct snd_soc_jack_gpio *gpio;

 	gpio = container_of(work, struct snd_soc_jack_gpio, work.work);
 	snd_soc_jack_gpio_detect(gpio);
 }

 /**
  * snd_soc_jack_add_gpios - Associate GPIO pins with an ASoC jack
  *
  * @jack:  ASoC jack
  * @count: number of pins
  * @gpios: array of gpio pins
  *
  * This function will request gpio, set data direction and request irq
  * for each gpio in the array.
  */
 int snd_soc_jack_add_gpios(struct snd_soc_jack *jack, int count,
 			struct snd_soc_jack_gpio *gpios)
 {
 	int i, ret;

 	for (i = 0; i < count; i++) {
 		if (!gpio_is_valid(gpios[i].gpio)) {
 			printk(KERN_ERR "Invalid gpio %d\n",
 				gpios[i].gpio);
 			ret = -EINVAL;
 			goto undo;
 		}
 		if (!gpios[i].name) {
 			printk(KERN_ERR "No name for gpio %d\n",
 				gpios[i].gpio);
 			ret = -EINVAL;
 			goto undo;
 		}

 		ret = gpio_request(gpios[i].gpio, gpios[i].name);
 		if (ret)
 			goto undo;

 		ret = gpio_direction_input(gpios[i].gpio);
 		if (ret)
 			goto err;

 		INIT_DELAYED_WORK(&gpios[i].work, gpio_work);
 		gpios[i].jack = jack;

 		ret = request_any_context_irq(gpio_to_irq(gpios[i].gpio),
 					      gpio_handler,
 					      IRQF_TRIGGER_RISING |
 					      IRQF_TRIGGER_FALLING,
 					      gpios[i].name,
 					      &gpios[i]);
 		if (ret < 0)
 			goto err;

 		if (gpios[i].wake) {
 			ret = irq_set_irq_wake(gpio_to_irq(gpios[i].gpio), 1);
 			if (ret != 0)
 				printk(KERN_ERR
 				  "Failed to mark GPIO %d as wake source: %d\n",
 					gpios[i].gpio, ret);
 		}

 #ifdef CONFIG_GPIO_SYSFS
 		/* Expose GPIO value over sysfs for diagnostic purposes */
 		gpio_export(gpios[i].gpio, false);
 #endif

 		/* Update initial jack status */
 		snd_soc_jack_gpio_detect(&gpios[i]);
 	}

 	return 0;

 err:
 	gpio_free(gpios[i].gpio);
 undo:
 	snd_soc_jack_free_gpios(jack, i, gpios);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_add_gpios);

 /**
  * snd_soc_jack_free_gpios - Release GPIO pins' resources of an ASoC jack
  *
  * @jack:  ASoC jack
  * @count: number of pins
  * @gpios: array of gpio pins
  *
  * Release gpio and irq resources for gpio pins associated with an ASoC jack.
  */
 void snd_soc_jack_free_gpios(struct snd_soc_jack *jack, int count,
 			struct snd_soc_jack_gpio *gpios)
 {
 	int i;

 	for (i = 0; i < count; i++) {
 #ifdef CONFIG_GPIO_SYSFS
 		gpio_unexport(gpios[i].gpio);
 #endif
 		free_irq(gpio_to_irq(gpios[i].gpio), &gpios[i]);
 		cancel_delayed_work_sync(&gpios[i].work);
 		gpio_free(gpios[i].gpio);
 		gpios[i].jack = NULL;
 	}
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_free_gpios);
 #endif	/* CONFIG_GPIOLIB */
	/*
	* soc-jack.c -- ALSA SoC jack handling
	*
	* Copyright 2008 Wolfson Microelectronics PLC.
	*
	* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*/

	#include <sound/jack.h>
	#include <sound/soc.h>
	#include <linux/gpio.h>
	#include <linux/interrupt.h>
	#include <linux/workqueue.h>
	#include <linux/delay.h>
	#include <trace/events/asoc.h>

	/**
	* snd_soc_jack_new - Create a new jack
	* @card: ASoC card
	* @id: an identifying string for this jack
	* @type: a bitmask of enum snd_jack_type values that can be detected by
	* this jack
	* @jack: structure to use for the jack
	*
	* Creates a new jack object.
	*
	* Returns zero if successful, or a negative error code on failure.
	* On success jack will be initialised.
	*/
	int snd_soc_jack_new(struct snd_soc_codec codec, const char id, int type,
	struct snd_soc_jack *jack)
	{
	jack->codec = codec;
	INIT_LIST_HEAD(&jack->pins);
	INIT_LIST_HEAD(&jack->jack_zones);
	BLOCKING_INIT_NOTIFIER_HEAD(&jack->notifier);

	return snd_jack_new(codec->card->snd_card, id, type, &jack->jack);
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_new);

	/**
	* snd_soc_jack_report - Report the current status for a jack
	*
	* @jack: the jack
	* @status: a bitmask of enum snd_jack_type values that are currently detected.
	* @mask: a bitmask of enum snd_jack_type values that being reported.
	*
	* If configured using snd_soc_jack_add_pins() then the associated
	* DAPM pins will be enabled or disabled as appropriate and DAPM
	* synchronised.
	*
	* Note: This function uses mutexes and should be called from a
	* context which can sleep (such as a workqueue).
	*/
	void snd_soc_jack_report(struct snd_soc_jack *jack, int status, int mask)
	{
	struct snd_soc_codec *codec;
	struct snd_soc_dapm_context *dapm;
	struct snd_soc_jack_pin *pin;
	int enable;
	int oldstatus;

	trace_snd_soc_jack_report(jack, mask, status);

	if (!jack)
	return;

	codec = jack->codec;
	dapm = &codec->dapm;

	mutex_lock(&codec->mutex);

	oldstatus = jack->status;

	jack->status &= ~mask;
	jack->status \|= status & mask;

	/* The DAPM sync is expensive enough to be worth skipping.
	* However, empty mask means pin synchronization is desired. */
	if (mask && (jack->status == oldstatus))
	goto out;

	trace_snd_soc_jack_notify(jack, status);

	list_for_each_entry(pin, &jack->pins, list) {
	enable = pin->mask & jack->status;

	if (pin->invert)
	enable = !enable;

	if (enable)
	snd_soc_dapm_enable_pin(dapm, pin->pin);
	else
	snd_soc_dapm_disable_pin(dapm, pin->pin);
	}

	/* Report before the DAPM sync to help users updating micbias status */
	blocking_notifier_call_chain(&jack->notifier, status, jack);

	snd_soc_dapm_sync(dapm);

	snd_jack_report(jack->jack, jack->status);

	out:
	mutex_unlock(&codec->mutex);
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_report);

	/**
	* snd_soc_jack_report_no_dapm - Report the current status for a jack
	* without DAPM sync
	* @jack: the jack
	* @status: a bitmask of enum snd_jack_type values that are currently detected.
	* @mask: a bitmask of enum snd_jack_type values that being reported.
	*/
	void snd_soc_jack_report_no_dapm(struct snd_soc_jack *jack, int status,
	int mask)
	{
	jack->status &= ~mask;
	jack->status \|= status & mask;

	snd_jack_report(jack->jack, jack->status);
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_report_no_dapm);

	/**
	* snd_soc_jack_add_zones - Associate voltage zones with jack
	*
	* @jack: ASoC jack
	* @count: Number of zones
	* @zone: Array of zones
	*
	* After this function has been called the zones specified in the
	* array will be associated with the jack.
	*/
	int snd_soc_jack_add_zones(struct snd_soc_jack *jack, int count,
	struct snd_soc_jack_zone *zones)
	{
	int i;

	for (i = 0; i < count; i++) {
	INIT_LIST_HEAD(&zones[i].list);
	list_add(&(zones[i].list), &jack->jack_zones);
	}
	return 0;
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_add_zones);

	/**
	* snd_soc_jack_get_type - Based on the mic bias value, this function returns
	* the type of jack from the zones delcared in the jack type
	*
	* @micbias_voltage: mic bias voltage at adc channel when jack is plugged in
	*
	* Based on the mic bias value passed, this function helps identify
	* the type of jack from the already delcared jack zones
	*/
	int snd_soc_jack_get_type(struct snd_soc_jack *jack, int micbias_voltage)
	{
	struct snd_soc_jack_zone *zone;

	list_for_each_entry(zone, &jack->jack_zones, list) {
	if (micbias_voltage >= zone->min_mv &&
	micbias_voltage < zone->max_mv)
	return zone->jack_type;
	}
	return 0;
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_get_type);

	/**
	* snd_soc_jack_add_pins - Associate DAPM pins with an ASoC jack
	*
	* @jack: ASoC jack
	* @count: Number of pins
	* @pins: Array of pins
	*
	* After this function has been called the DAPM pins specified in the
	* pins array will have their status updated to reflect the current
	* state of the jack whenever the jack status is updated.
	*/
	int snd_soc_jack_add_pins(struct snd_soc_jack *jack, int count,
	struct snd_soc_jack_pin *pins)
	{
	int i;

	for (i = 0; i < count; i++) {
	if (!pins[i].pin) {
	printk(KERN_ERR "No name for pin %d\n", i);
	return -EINVAL;
	}
	if (!pins[i].mask) {
	printk(KERN_ERR "No mask for pin %d (%s)\n", i,
	pins[i].pin);
	return -EINVAL;
	}

	INIT_LIST_HEAD(&pins[i].list);
	list_add(&(pins[i].list), &jack->pins);
	}

	/* Update to reflect the last reported status; canned jack
	* implementations are likely to set their state before the
	* card has an opportunity to associate pins.
	*/
	snd_soc_jack_report(jack, 0, 0);

	return 0;
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_add_pins);

	/**
	* snd_soc_jack_notifier_register - Register a notifier for jack status
	*
	* @jack: ASoC jack
	* @nb: Notifier block to register
	*
	* Register for notification of the current status of the jack. Note
	* that it is not possible to report additional jack events in the
	* callback from the notifier, this is intended to support
	* applications such as enabling electrical detection only when a
	* mechanical detection event has occurred.
	*/
	void snd_soc_jack_notifier_register(struct snd_soc_jack *jack,
	struct notifier_block *nb)
	{
	blocking_notifier_chain_register(&jack->notifier, nb);
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_register);

	/**
	* snd_soc_jack_notifier_unregister - Unregister a notifier for jack status
	*
	* @jack: ASoC jack
	* @nb: Notifier block to unregister
	*
	* Stop notifying for status changes.
	*/
	void snd_soc_jack_notifier_unregister(struct snd_soc_jack *jack,
	struct notifier_block *nb)
	{
	blocking_notifier_chain_unregister(&jack->notifier, nb);
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_unregister);

	#ifdef CONFIG_GPIOLIB
	/* gpio detect */
	static void snd_soc_jack_gpio_detect(struct snd_soc_jack_gpio *gpio)
	{
	struct snd_soc_jack *jack = gpio->jack;
	int enable;
	int report;

	enable = gpio_get_value_cansleep(gpio->gpio);
	if (gpio->invert)
	enable = !enable;

	if (enable)
	report = gpio->report;
	else
	report = 0;

	if (gpio->jack_status_check)
	report = gpio->jack_status_check();

	snd_soc_jack_report(jack, report, gpio->report);
	}

	/* irq handler for gpio pin */
	static irqreturn_t gpio_handler(int irq, void *data)
	{
	struct snd_soc_jack_gpio *gpio = data;
	struct device *dev = gpio->jack->codec->card->dev;

	trace_snd_soc_jack_irq(gpio->name);

	if (device_may_wakeup(dev))
	pm_wakeup_event(dev, gpio->debounce_time + 50);

	schedule_delayed_work(&gpio->work,
	msecs_to_jiffies(gpio->debounce_time));

	return IRQ_HANDLED;
	}

	/* gpio work */
	static void gpio_work(struct work_struct *work)
	{
	struct snd_soc_jack_gpio *gpio;

	gpio = container_of(work, struct snd_soc_jack_gpio, work.work);
	snd_soc_jack_gpio_detect(gpio);
	}

	/**
	* snd_soc_jack_add_gpios - Associate GPIO pins with an ASoC jack
	*
	* @jack: ASoC jack
	* @count: number of pins
	* @gpios: array of gpio pins
	*
	* This function will request gpio, set data direction and request irq
	* for each gpio in the array.
	*/
	int snd_soc_jack_add_gpios(struct snd_soc_jack *jack, int count,
	struct snd_soc_jack_gpio *gpios)
	{
	int i, ret;

	for (i = 0; i < count; i++) {
	if (!gpio_is_valid(gpios[i].gpio)) {
	printk(KERN_ERR "Invalid gpio %d\n",
	gpios[i].gpio);
	ret = -EINVAL;
	goto undo;
	}
	if (!gpios[i].name) {
	printk(KERN_ERR "No name for gpio %d\n",
	gpios[i].gpio);
	ret = -EINVAL;
	goto undo;
	}

	ret = gpio_request(gpios[i].gpio, gpios[i].name);
	if (ret)
	goto undo;

	ret = gpio_direction_input(gpios[i].gpio);
	if (ret)
	goto err;

	INIT_DELAYED_WORK(&gpios[i].work, gpio_work);
	gpios[i].jack = jack;

	ret = request_any_context_irq(gpio_to_irq(gpios[i].gpio),
	gpio_handler,
	IRQF_TRIGGER_RISING \|
	IRQF_TRIGGER_FALLING,
	gpios[i].name,
	&gpios[i]);
	if (ret < 0)
	goto err;

	if (gpios[i].wake) {
	ret = irq_set_irq_wake(gpio_to_irq(gpios[i].gpio), 1);
	if (ret != 0)
	printk(KERN_ERR
	"Failed to mark GPIO %d as wake source: %d\n",
	gpios[i].gpio, ret);
	}

	#ifdef CONFIG_GPIO_SYSFS
	/* Expose GPIO value over sysfs for diagnostic purposes */
	gpio_export(gpios[i].gpio, false);
	#endif

	/* Update initial jack status */
	snd_soc_jack_gpio_detect(&gpios[i]);
	}

	return 0;

	err:
	gpio_free(gpios[i].gpio);
	undo:
	snd_soc_jack_free_gpios(jack, i, gpios);

	return ret;
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_add_gpios);

	/**
	* snd_soc_jack_free_gpios - Release GPIO pins' resources of an ASoC jack
	*
	* @jack: ASoC jack
	* @count: number of pins
	* @gpios: array of gpio pins
	*
	* Release gpio and irq resources for gpio pins associated with an ASoC jack.
	*/
	void snd_soc_jack_free_gpios(struct snd_soc_jack *jack, int count,
	struct snd_soc_jack_gpio *gpios)
	{
	int i;

	for (i = 0; i < count; i++) {
	#ifdef CONFIG_GPIO_SYSFS
	gpio_unexport(gpios[i].gpio);
	#endif
	free_irq(gpio_to_irq(gpios[i].gpio), &gpios[i]);
	cancel_delayed_work_sync(&gpios[i].work);
	gpio_free(gpios[i].gpio);
	gpios[i].jack = NULL;
	}
	}
	EXPORT_SYMBOL_GPL(snd_soc_jack_free_gpios);
	#endif /* CONFIG_GPIOLIB */