From 94d33c02c7186b69849c292e1216a08ad1c0d99d Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 2 Jul 2013 22:52:41 +0100 Subject: regulator: core: Add helpers for multiple linear ranges 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 --- drivers/regulator/core.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) (limited to 'drivers') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 288c75abc190..e8604be4c66d 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -2078,6 +2078,43 @@ 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 * @@ -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) { -- cgit v1.2.3