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Commit 412aec61 authored by David Brownell's avatar David Brownell Committed by Liam Girdwood
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regulator: enable/disable refcounting 



Make the <linux/regulator.h> framework treat enable/disable call
pairs like the <linux/clk.h> and <linux/interrupt.h> frameworks do:
they're refcounted, so that different parts of a driver don't need
to put work into coordination that frameworks normally handle.
It's a minor object code shrink.

It also makes the regulator_is_disabled() kerneldoc say what it's
actually returning:  return value is not a refcount, and may report
an error (e.g. I/O error from I2C).

It also fixes some minor regulator_put() goofage:  removing unlocked
access to the enable state.  (But still not making regulator put/get
match the refcounting pattern they invoke.)

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
parent 812460a9

drivers/regulator/core.c

+36 −35
Original line number Diff line number Diff line
@@ -79,7 +79,7 @@ struct regulator { 
	int uA_load;

	int min_uV;

	int max_uV;

	int enabled; /* client has called enabled */

	int enabled; /* count of client enables */

	char *supply_name;

	struct device_attribute dev_attr;

	struct regulator_dev *rdev;
@@ -963,16 +963,13 @@ void regulator_put(struct regulator *regulator) 
	if (regulator == NULL || IS_ERR(regulator))

		return;



	if (regulator->enabled) {

		printk(KERN_WARNING "Releasing supply %s while enabled\n",

		       regulator->supply_name);

		WARN_ON(regulator->enabled);

		regulator_disable(regulator);

	}



	mutex_lock(&regulator_list_mutex);

	rdev = regulator->rdev;



	if (WARN(regulator->enabled, "Releasing supply %s while enabled\n",

			       regulator->supply_name))

		_regulator_disable(rdev);



	/* remove any sysfs entries */

	if (regulator->dev) {

		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
@@ -1042,21 +1039,17 @@ static int _regulator_enable(struct regulator_dev *rdev) 
 */

int regulator_enable(struct regulator *regulator)

{

	int ret;



	if (regulator->enabled) {

		printk(KERN_CRIT "Regulator %s already enabled\n",

		       regulator->supply_name);

		WARN_ON(regulator->enabled);

		return 0;

	}

	struct regulator_dev *rdev = regulator->rdev;

	int ret = 0;



	mutex_lock(&regulator->rdev->mutex);

	regulator->enabled = 1;

	ret = _regulator_enable(regulator->rdev);

	if (ret != 0)

		regulator->enabled = 0;

	mutex_unlock(&regulator->rdev->mutex);

	mutex_lock(&rdev->mutex);

	if (regulator->enabled == 0)

		ret = _regulator_enable(rdev);

	else if (regulator->enabled < 0)

		ret = -EIO;

	if (ret == 0)

		regulator->enabled++;

	mutex_unlock(&rdev->mutex);

	return ret;

}

EXPORT_SYMBOL_GPL(regulator_enable);
@@ -1108,19 +1101,21 @@ static int _regulator_disable(struct regulator_dev *rdev) 
 */

int regulator_disable(struct regulator *regulator)

{

	int ret;



	if (!regulator->enabled) {

		printk(KERN_ERR "%s: not in use by this consumer\n",

			__func__);

		return 0;

	}

	struct regulator_dev *rdev = regulator->rdev;

	int ret = 0;



	mutex_lock(&regulator->rdev->mutex);

	regulator->enabled = 0;

	mutex_lock(&rdev->mutex);

	if (regulator->enabled == 1) {

		ret = _regulator_disable(rdev);

		if (ret == 0)

			regulator->uA_load = 0;

	ret = _regulator_disable(regulator->rdev);

	mutex_unlock(&regulator->rdev->mutex);

	} else if (WARN(regulator->enabled <= 0,

			"unbalanced disables for supply %s\n",

			regulator->supply_name))

		ret = -EIO;

	if (ret == 0)

		regulator->enabled--;

	mutex_unlock(&rdev->mutex);

	return ret;

}

EXPORT_SYMBOL_GPL(regulator_disable);
@@ -1196,7 +1191,13 @@ static int _regulator_is_enabled(struct regulator_dev *rdev) 
 * regulator_is_enabled - is the regulator output enabled

 * @regulator: regulator source

 *

 * Returns zero for disabled otherwise return number of enable requests.

 * Returns positive if the regulator driver backing the source/client

 * has requested that the device be enabled, zero if it hasn't, else a

 * negative errno code.

 *

 * Note that the device backing this regulator handle can have multiple

 * users, so it might be enabled even if regulator_enable() was never

 * called for this particular source.

 */

int regulator_is_enabled(struct regulator *regulator)

{