Add a new flag to struct regulator_desc indicating whether a regulator can be controlled from user space and implement a routine in regulator core allowing to toggle the regulator state via the sysfs 'state' attribute.
This is useful for gpio power switches. Signed-off-by: Bartosz Golaszewski <[email protected]> --- drivers/regulator/core.c | 38 +++++++++++++++++++++++++++++++++++++- include/linux/regulator/driver.h | 5 +++++ 2 files changed, 42 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 5c1519b..f77de8f 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -99,6 +99,7 @@ struct regulator_supply_alias { }; static int _regulator_is_enabled(struct regulator_dev *rdev); +static int _regulator_enable(struct regulator_dev *rdev); static int _regulator_disable(struct regulator_dev *rdev); static int _regulator_get_voltage(struct regulator_dev *rdev); static int _regulator_get_current_limit(struct regulator_dev *rdev); @@ -401,7 +402,42 @@ static ssize_t regulator_state_show(struct device *dev, return ret; } -static DEVICE_ATTR(state, 0444, regulator_state_show, NULL); +static ssize_t regulator_state_set(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct regulator_dev *rdev = dev_get_drvdata(dev); + bool enable; + ssize_t ret; + + if (!rdev->desc->userspace_control) + return -EPERM; + + if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1")) + enable = true; + else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0")) + enable = false; + else + return -EINVAL; + + mutex_lock(&rdev->mutex); + + if ((enable && _regulator_is_enabled(rdev)) || + (!enable && !_regulator_is_enabled(rdev))) { + mutex_unlock(&rdev->mutex); + return -EBUSY; + } + + ret = enable ? _regulator_enable(rdev) : _regulator_disable(rdev); + + mutex_unlock(&rdev->mutex); + + if (ret) + return ret; + + return len; +} +static DEVICE_ATTR(state, 0644, regulator_state_show, regulator_state_set); static ssize_t regulator_status_show(struct device *dev, struct device_attribute *attr, char *buf) diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index 37b5324..0e7ad95 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -293,6 +293,9 @@ enum regulator_type { * @off_on_delay: guard time (in uS), before re-enabling a regulator * * @of_map_mode: Maps a hardware mode defined in a DeviceTree to a standard mode + * + * @userspace_control: A flag to indicate whether this regulator can be + * controlled from user-space. */ struct regulator_desc { const char *name; @@ -347,6 +350,8 @@ struct regulator_desc { unsigned int off_on_delay; unsigned int (*of_map_mode)(unsigned int mode); + + unsigned int userspace_control; }; /** -- 2.9.3
