linux/sound/soc/soc-jack.c
Mark Brown 2667b4b8be ASoC: jack: Push locking for jacks down to the jack
Currently operations on jack reporting take the CODEC mutex both to protect
the current jack status and also to protect the DAPM run which is triggered
on status updates. Since the addition of a DAPM-specific lock we no longer
need to worry about locking DAPM as it has its own finer grained lock so
create a per jack lock to take care of the jack status.

This is both cleaner where the jack isn't specifically associated with a
CODEC and clearer as it's much more obvious what the lock is protecting.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-04-01 11:28:23 +01:00

386 lines
9.6 KiB
C

/*
* 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 <linux/export.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)
{
mutex_init(&jack->mutex);
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(&jack->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(&jack->mutex);
}
EXPORT_SYMBOL_GPL(snd_soc_jack_report);
/**
* 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);
}
snd_soc_dapm_new_widgets(&jack->codec->card->dapm);
/* 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);
}
/* Expose GPIO value over sysfs for diagnostic purposes */
gpio_export(gpios[i].gpio, false);
/* 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++) {
gpio_unexport(gpios[i].gpio);
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 */