From: Mark Brown broonie@linaro.org
Many regulators have several linear ranges of selector with different step sizes, for example offering better resolution at lower voltages. Provide regulator_{map,list}_voltage_linear_range() allowing these regulators to use generic code. To do so a table of regulator_linear_range structs needs to be pointed to from the descriptor.
This was inspired by similar code included in a driver submission from Chao Xie and Yi Zhang at Marvell.
Signed-off-by: Mark Brown broonie@linaro.org --- drivers/regulator/core.c | 87 ++++++++++++++++++++++++++++++++++++++++ include/linux/regulator/driver.h | 25 ++++++++++++ 2 files changed, 112 insertions(+)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 288c75a..e8604be 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -2079,6 +2079,43 @@ int regulator_list_voltage_linear(struct regulator_dev *rdev, EXPORT_SYMBOL_GPL(regulator_list_voltage_linear);
/** + * regulator_list_voltage_linear_range - List voltages for linear ranges + * + * @rdev: Regulator device + * @selector: Selector to convert into a voltage + * + * Regulators with a series of simple linear mappings between voltages + * and selectors can set linear_ranges in the regulator descriptor and + * then use this function as their list_voltage() operation, + */ +int regulator_list_voltage_linear_range(struct regulator_dev *rdev, + unsigned int selector) +{ + const struct regulator_linear_range *range; + int i; + + if (!rdev->desc->n_linear_ranges) { + BUG_ON(!rdev->desc->n_linear_ranges); + return -EINVAL; + } + + for (i = 0; i < rdev->desc->n_linear_ranges; i++) { + range = &rdev->desc->linear_ranges[i]; + + if (!(selector >= range->min_sel && + selector <= range->max_sel)) + continue; + + selector -= range->min_sel; + + return range->min_uV + (range->uV_step * selector); + } + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(regulator_list_voltage_linear_range); + +/** * regulator_list_voltage_table - List voltages with table based mapping * * @rdev: Regulator device @@ -2368,6 +2405,56 @@ int regulator_map_voltage_linear(struct regulator_dev *rdev, } EXPORT_SYMBOL_GPL(regulator_map_voltage_linear);
+/** + * regulator_map_voltage_linear - map_voltage() for multiple linear ranges + * + * @rdev: Regulator to operate on + * @min_uV: Lower bound for voltage + * @max_uV: Upper bound for voltage + * + * Drivers providing linear_ranges in their descriptor can use this as + * their map_voltage() callback. + */ +int regulator_map_voltage_linear_range(struct regulator_dev *rdev, + int min_uV, int max_uV) +{ + const struct regulator_linear_range *range; + int ret = -EINVAL; + int voltage, i; + + if (!rdev->desc->n_linear_ranges) { + BUG_ON(!rdev->desc->n_linear_ranges); + return -EINVAL; + } + + for (i = 0; i < rdev->desc->n_linear_ranges; i++) { + range = &rdev->desc->linear_ranges[i]; + + if (!(min_uV <= range->max_uV && max_uV >= range->min_uV)) + continue; + + if (min_uV <= range->min_uV) + min_uV = range->min_uV; + + ret = DIV_ROUND_UP(min_uV - range->min_uV, range->uV_step); + if (ret < 0) + return ret; + + break; + } + + if (i == rdev->desc->n_linear_ranges) + return -EINVAL; + + /* Map back into a voltage to verify we're still in bounds */ + voltage = rdev->desc->ops->list_voltage(rdev, ret); + if (voltage < min_uV || voltage > max_uV) + return -EINVAL; + + return ret; +} +EXPORT_SYMBOL_GPL(regulator_map_voltage_linear_range); + static int _regulator_do_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV) { diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index 6700cc9..67e13aa 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -40,6 +40,24 @@ enum regulator_status { };
/** + * Specify a range of voltages for regulator_map_linar_range() and + * regulator_list_linear_range(). + * + * @min_uV: Lowest voltage in range + * @max_uV: Highest voltage in range + * @min_sel: Lowest selector for range + * @max_sel: Highest selector for range + * @uV_step: Step size + */ +struct regulator_linear_range { + unsigned int min_uV; + unsigned int max_uV; + unsigned int min_sel; + unsigned int max_sel; + unsigned int uV_step; +}; + +/** * struct regulator_ops - regulator operations. * * @enable: Configure the regulator as enabled. @@ -223,6 +241,9 @@ struct regulator_desc { unsigned int linear_min_sel; unsigned int ramp_delay;
+ const struct regulator_linear_range *linear_ranges; + int n_linear_ranges; + const unsigned int *volt_table;
unsigned int vsel_reg; @@ -326,10 +347,14 @@ int regulator_mode_to_status(unsigned int);
int regulator_list_voltage_linear(struct regulator_dev *rdev, unsigned int selector); +int regulator_list_voltage_linear_range(struct regulator_dev *rdev, + unsigned int selector); int regulator_list_voltage_table(struct regulator_dev *rdev, unsigned int selector); int regulator_map_voltage_linear(struct regulator_dev *rdev, int min_uV, int max_uV); +int regulator_map_voltage_linear_range(struct regulator_dev *rdev, + int min_uV, int max_uV); int regulator_map_voltage_iterate(struct regulator_dev *rdev, int min_uV, int max_uV); int regulator_map_voltage_ascend(struct regulator_dev *rdev,