When voltage constraints are given in the device tree then we should set the regulator to a valid voltage before enabling it. Without it we can end up with invalid voltages.
Signed-off-by: Sascha Hauer <[email protected]> --- drivers/regulator/core.c | 60 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index d08df1dc68..00a2aefce7 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -187,6 +187,62 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) return 0; } +static int regulator_init_voltage(struct regulator_dev *rdev) +{ + int target_min, target_max, current_uV, ret; + + if (!rdev->min_uv || !rdev->max_uv) + return 0; + + current_uV = regulator_get_voltage_internal(rdev); + if (current_uV < 0) { + /* This regulator can't be read and must be initialized */ + rdev_info(rdev, "Setting %d-%duV\n", rdev->min_uv, rdev->max_uv); + regulator_set_voltage_internal(rdev, rdev->min_uv, rdev->max_uv); + current_uV = regulator_get_voltage_internal(rdev); + } + + if (current_uV < 0) { + if (current_uV != -EPROBE_DEFER) + rdev_err(rdev, + "failed to get the current voltage: %pe\n", + ERR_PTR(current_uV)); + return current_uV; + } + + /* + * If we're below the minimum voltage move up to the + * minimum voltage, if we're above the maximum voltage + * then move down to the maximum. + */ + target_min = current_uV; + target_max = current_uV; + + if (current_uV < rdev->min_uv) { + target_min = rdev->min_uv; + target_max = rdev->min_uv; + } + + if (current_uV > rdev->max_uv) { + target_min = rdev->max_uv; + target_max = rdev->max_uv; + } + + if (target_min != current_uV || target_max != current_uV) { + rdev_info(rdev, "Bringing %duV into %d-%duV\n", + current_uV, target_min, target_max); + ret = regulator_set_voltage_internal(rdev, target_min, target_max); + if (ret < 0) { + rdev_err(rdev, + "failed to apply %d-%duV constraint: %pe\n", + target_min, target_max, ERR_PTR(ret)); + return ret; + } + } + + return 0; +} + static int __regulator_register(struct regulator_dev *rdev, const char *name) { int ret; @@ -198,6 +254,10 @@ static int __regulator_register(struct regulator_dev *rdev, const char *name) if (name) rdev->name = xstrdup(name); + ret = regulator_init_voltage(rdev); + if (ret) + goto err; + if (rdev->boot_on || rdev->always_on) { ret = regulator_resolve_supply(rdev); if (ret < 0) -- 2.39.2
