kernel_optimize_test/sound/soc/soc-jack.c
Lars-Peter Clausen b8e22c1fe3 ASoC: jack: Fix race in snd_soc_jack_add_gpios
The irq can fire as soon as it has been requested, thus all fields accessed
from within the irq handler must be initialized prior to requesting the irq.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2009-07-31 22:38:43 +01:00

280 lines
6.5 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 <sound/soc-dapm.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/delay.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_card *card, const char *id, int type,
struct snd_soc_jack *jack)
{
jack->card = card;
INIT_LIST_HEAD(&jack->pins);
return snd_jack_new(card->codec->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 = jack->card->codec;
struct snd_soc_jack_pin *pin;
int enable;
int oldstatus;
if (!jack) {
WARN_ON_ONCE(!jack);
return;
}
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;
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(codec, pin->pin);
else
snd_soc_dapm_disable_pin(codec, pin->pin);
}
snd_soc_dapm_sync(codec);
snd_jack_report(jack->jack, status);
out:
mutex_unlock(&codec->mutex);
}
EXPORT_SYMBOL_GPL(snd_soc_jack_report);
/**
* 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);
#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;
if (gpio->debounce_time > 0)
mdelay(gpio->debounce_time);
enable = gpio_get_value(gpio->gpio);
if (gpio->invert)
enable = !enable;
if (enable)
report = gpio->report;
else
report = 0;
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;
schedule_work(&gpio->work);
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);
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_WORK(&gpios[i].work, gpio_work);
gpios[i].jack = jack;
ret = request_irq(gpio_to_irq(gpios[i].gpio),
gpio_handler,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
jack->card->dev->driver->name,
&gpios[i]);
if (ret)
goto err;
#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]);
gpio_free(gpios[i].gpio);
gpios[i].jack = NULL;
}
}
EXPORT_SYMBOL_GPL(snd_soc_jack_free_gpios);
#endif /* CONFIG_GPIOLIB */