From: Bartosz Golaszewski <[email protected]> Some regulators require that the requested voltage be reached gradually by setting all or some of the intermediate values. Implement a new field in the regulator description struct that allows users to specify the number of selectors by which the regulator API should step when ramping the voltage up/down.
Signed-off-by: Bartosz Golaszewski <[email protected]> --- drivers/regulator/core.c | 63 ++++++++++++++++++++++++++++++++ include/linux/regulator/driver.h | 6 +++ 2 files changed, 69 insertions(+) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 9d3ed13b7f12..df82e2a8442a 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -3106,6 +3106,66 @@ static int _regulator_call_set_voltage_sel(struct regulator_dev *rdev, return ret; } +static int _regulator_set_voltage_sel_step(struct regulator_dev *rdev, + int uV, int new_selector) +{ + const struct regulator_ops *ops = rdev->desc->ops; + int diff, old_sel, curr_sel, ret; + + /* Stepping is only needed if the regulator is enabled. */ + if (!_regulator_is_enabled(rdev)) + goto final_set; + + if (!ops->get_voltage_sel) + return -EINVAL; + + old_sel = ops->get_voltage_sel(rdev); + if (old_sel < 0) + return old_sel; + + diff = new_selector - old_sel; + if (diff == 0) + return 0; /* No change needed. */ + + if (diff > 0) { + /* Stepping up. */ + for (curr_sel = old_sel + rdev->desc->vsel_step; + curr_sel < new_selector; + curr_sel += rdev->desc->vsel_step) { + /* + * Call the callback directly instead of using + * _regulator_call_set_voltage_sel() as we don't + * want to notify anyone yet. Same in the branch + * below. + */ + ret = ops->set_voltage_sel(rdev, curr_sel); + if (ret) + goto try_revert; + } + } else { + /* Stepping down. */ + for (curr_sel = old_sel - rdev->desc->vsel_step; + curr_sel > new_selector; + curr_sel -= rdev->desc->vsel_step) { + ret = ops->set_voltage_sel(rdev, curr_sel); + if (ret) + goto try_revert; + } + } + +final_set: + /* The final selector will trigger the notifiers. */ + return _regulator_call_set_voltage_sel(rdev, uV, new_selector); + +try_revert: + /* + * At least try to return to the previous voltage if setting a new + * one failed. + */ + (void)ops->set_voltage_sel(rdev, old_sel); + return ret; +} + static int _regulator_set_voltage_time(struct regulator_dev *rdev, int old_uV, int new_uV) { @@ -3179,6 +3239,9 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev, selector = ret; if (old_selector == selector) ret = 0; + else if (rdev->desc->vsel_step) + ret = _regulator_set_voltage_sel_step( + rdev, best_val, selector); else ret = _regulator_call_set_voltage_sel( rdev, best_val, selector); diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index 377da2357118..f0d7b0496e54 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -286,6 +286,11 @@ enum regulator_type { * @vsel_range_mask: Mask for register bitfield used for range selector * @vsel_reg: Register for selector when using regulator_regmap_X_voltage_ * @vsel_mask: Mask for register bitfield used for selector + * @vsel_step: Specify the resolution of selector stepping when setting + * voltage. If 0, then no stepping is done (requested selector is + * set directly), if >0 then the regulator API will ramp the + * voltage up/down gradually each time increasing/decreasing the + * selector by the specified step value. * @csel_reg: Register for current limit selector using regmap set_current_limit * @csel_mask: Mask for register bitfield used for current limit selector * @apply_reg: Register for initiate voltage change on the output when @@ -360,6 +365,7 @@ struct regulator_desc { unsigned int vsel_range_mask; unsigned int vsel_reg; unsigned int vsel_mask; + unsigned int vsel_step; unsigned int csel_reg; unsigned int csel_mask; unsigned int apply_reg; -- 2.21.0
