diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/regulator/core.c | 88 |
1 files changed, 74 insertions, 14 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 24e05b7607b..68549008582 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1025,25 +1025,15 @@ overflow_err: return NULL; } -/** - * regulator_get - lookup and obtain a reference to a regulator. - * @dev: device for regulator "consumer" - * @id: Supply name or regulator ID. - * - * Returns a struct regulator corresponding to the regulator producer, - * or IS_ERR() condition containing errno. - * - * Use of supply names configured via regulator_set_device_supply() is - * strongly encouraged. It is recommended that the supply name used - * should match the name used for the supply and/or the relevant - * device pins in the datasheet. - */ -struct regulator *regulator_get(struct device *dev, const char *id) +/* Internal regulator request function */ +static struct regulator *_regulator_get(struct device *dev, const char *id, + int exclusive) { struct regulator_dev *rdev; struct regulator_map *map; struct regulator *regulator = ERR_PTR(-ENODEV); const char *devname = NULL; + int ret; if (id == NULL) { printk(KERN_ERR "regulator: get() with no identifier\n"); @@ -1070,6 +1060,16 @@ struct regulator *regulator_get(struct device *dev, const char *id) return regulator; found: + if (rdev->exclusive) { + regulator = ERR_PTR(-EPERM); + goto out; + } + + if (exclusive && rdev->open_count) { + regulator = ERR_PTR(-EBUSY); + goto out; + } + if (!try_module_get(rdev->owner)) goto out; @@ -1079,13 +1079,70 @@ found: module_put(rdev->owner); } + rdev->open_count++; + if (exclusive) { + rdev->exclusive = 1; + + ret = _regulator_is_enabled(rdev); + if (ret > 0) + rdev->use_count = 1; + else + rdev->use_count = 0; + } + out: mutex_unlock(®ulator_list_mutex); + return regulator; } + +/** + * regulator_get - lookup and obtain a reference to a regulator. + * @dev: device for regulator "consumer" + * @id: Supply name or regulator ID. + * + * Returns a struct regulator corresponding to the regulator producer, + * or IS_ERR() condition containing errno. + * + * Use of supply names configured via regulator_set_device_supply() is + * strongly encouraged. It is recommended that the supply name used + * should match the name used for the supply and/or the relevant + * device pins in the datasheet. + */ +struct regulator *regulator_get(struct device *dev, const char *id) +{ + return _regulator_get(dev, id, 0); +} EXPORT_SYMBOL_GPL(regulator_get); /** + * regulator_get_exclusive - obtain exclusive access to a regulator. + * @dev: device for regulator "consumer" + * @id: Supply name or regulator ID. + * + * Returns a struct regulator corresponding to the regulator producer, + * or IS_ERR() condition containing errno. Other consumers will be + * unable to obtain this reference is held and the use count for the + * regulator will be initialised to reflect the current state of the + * regulator. + * + * This is intended for use by consumers which cannot tolerate shared + * use of the regulator such as those which need to force the + * regulator off for correct operation of the hardware they are + * controlling. + * + * Use of supply names configured via regulator_set_device_supply() is + * strongly encouraged. It is recommended that the supply name used + * should match the name used for the supply and/or the relevant + * device pins in the datasheet. + */ +struct regulator *regulator_get_exclusive(struct device *dev, const char *id) +{ + return _regulator_get(dev, id, 1); +} +EXPORT_SYMBOL_GPL(regulator_get_exclusive); + +/** * regulator_put - "free" the regulator source * @regulator: regulator source * @@ -1113,6 +1170,9 @@ void regulator_put(struct regulator *regulator) list_del(®ulator->list); kfree(regulator); + rdev->open_count--; + rdev->exclusive = 0; + module_put(rdev->owner); mutex_unlock(®ulator_list_mutex); } |