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Commit fc1dcb0b authored by Akinobu Mita's avatar Akinobu Mita Committed by Alexandre Belloni
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rtc: ds3232: use rtc->ops_lock to protect alarm operations 



ds3232->mutex is used to protect for alarm operations which
need to access status and control registers.

But we can use rtc->ops_lock instead.  rtc->ops_lock is held when most
of rtc_class_ops methods are called, so we only need to explicitly
acquire it from irq handler in order to protect form concurrent
accesses.

Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent 95c60c1c

drivers/rtc/rtc-ds3232.c

+4 −21
Original line number Diff line number Diff line
@@ -52,11 +52,6 @@ struct ds3232 { 
	int irq;

	struct rtc_device *rtc;



	/* The mutex protects alarm operations, and prevents a race

	 * between the enable_irq() in the workqueue and the free_irq()

	 * in the remove function.

	 */

	struct mutex mutex;

	bool suspended;

};
@@ -187,8 +182,6 @@ static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
	int ret;

	u8 buf[4];



	mutex_lock(&ds3232->mutex);



	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);

	if (ret)

		goto out;
@@ -215,7 +208,6 @@ static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 


	ret = 0;

out:

	mutex_unlock(&ds3232->mutex);

	return ret;

}
@@ -233,8 +225,6 @@ static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
	if (ds3232->irq <= 0)

		return -EINVAL;



	mutex_lock(&ds3232->mutex);



	buf[0] = bin2bcd(alarm->time.tm_sec);

	buf[1] = bin2bcd(alarm->time.tm_min);

	buf[2] = bin2bcd(alarm->time.tm_hour);
@@ -267,7 +257,6 @@ static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
		ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);

	}

out:

	mutex_unlock(&ds3232->mutex);

	return ret;

}
@@ -277,11 +266,9 @@ static int ds3232_update_alarm(struct device *dev, unsigned int enabled) 
	int control;

	int ret;



	mutex_lock(&ds3232->mutex);



	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);

	if (ret)

		goto unlock;

		return ret;



	if (enabled)

		/* enable alarm1 interrupt */
@@ -291,9 +278,6 @@ static int ds3232_update_alarm(struct device *dev, unsigned int enabled) 
		control &= ~(DS3232_REG_CR_A1IE);

	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);



unlock:

	mutex_unlock(&ds3232->mutex);



	return ret;

}
@@ -311,10 +295,11 @@ static irqreturn_t ds3232_irq(int irq, void *dev_id) 
{

	struct device *dev = dev_id;

	struct ds3232 *ds3232 = dev_get_drvdata(dev);

	struct mutex *lock = &ds3232->rtc->ops_lock;

	int ret;

	int stat, control;



	mutex_lock(&ds3232->mutex);

	mutex_lock(lock);



	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);

	if (ret)
@@ -352,7 +337,7 @@ static irqreturn_t ds3232_irq(int irq, void *dev_id) 
	}



unlock:

	mutex_unlock(&ds3232->mutex);

	mutex_unlock(lock);



	return IRQ_HANDLED;

}
@@ -380,8 +365,6 @@ static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq, 
	ds3232->dev = dev;

	dev_set_drvdata(dev, ds3232);



	mutex_init(&ds3232->mutex);



	ret = ds3232_check_rtc_status(dev);

	if (ret)

		return ret;