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author | 2013-07-02 22:52:41 +0100 | |
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committer | 2013-07-15 11:20:32 +0100 | |
commit | 94d33c02c7186b69849c292e1216a08ad1c0d99d (patch) | |
tree | 7427db70b59494e1d8e3f295123ab1fd2d53f663 /drivers/regulator/core.c | |
parent | Linux 3.11-rc1 (diff) | |
download | linux-94d33c02c7186b69849c292e1216a08ad1c0d99d.tar.gz linux-94d33c02c7186b69849c292e1216a08ad1c0d99d.tar.bz2 linux-94d33c02c7186b69849c292e1216a08ad1c0d99d.zip |
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 <broonie@linaro.org>
Diffstat (limited to 'drivers/regulator/core.c')
-rw-r--r-- | drivers/regulator/core.c | 87 |
1 files changed, 87 insertions, 0 deletions
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 @@ -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) { |