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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: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
hifive-unleashed-5.1
David Brownell 2008-11-16 11:44:46 -08:00 committed by Liam Girdwood
parent 812460a927
commit 412aec6105
1 changed files with 36 additions and 35 deletions
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71
drivers/regulator/core.c
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@ -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;
struct regulator_dev *rdev = regulator->rdev;
int ret = 0;
if (regulator->enabled) {
printk(KERN_CRIT "Regulator %s already enabled\n",
regulator->supply_name);
WARN_ON(regulator->enabled);
return 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;
struct regulator_dev *rdev = regulator->rdev;
int ret = 0;
if (!regulator->enabled) {
printk(KERN_ERR "%s: not in use by this consumer\n",
__func__);
return 0;
}
mutex_lock(&regulator->rdev->mutex);
regulator->enabled = 0;
regulator->uA_load = 0;
ret = _regulator_disable(regulator->rdev);
mutex_unlock(&regulator->rdev->mutex);
mutex_lock(&rdev->mutex);
if (regulator->enabled == 1) {
ret = _regulator_disable(rdev);
if (ret == 0)
regulator->uA_load = 0;
} 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 @@ out:
* 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)
{