From fa93fd4ecc9c58475abac6db93a797bff893bc16 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 21 Mar 2016 18:12:52 +0000 Subject: [PATCH] regulator: core: Ensure we are at least in bounds for our constraints Currently we only attempt to set the voltage during constraints application if an exact voltage is specified. Extend this so that if the currently set voltage for the regulator is outside the bounds set in constraints we will move the voltage to the nearest constraint, raising to the minimum or lowering to the maximum as needed. This ensures that drivers can probe without the hardware being driven out of spec. Reported-by: Ivaylo Dimitrov Tested-by: Ivaylo Dimitrov Signed-off-by: Mark Brown --- drivers/regulator/core.c | 32 +++++++++++++++++++++++++------- drivers/regulator/of_regulator.c | 2 +- 2 files changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index e0b764284773..881c37e61f75 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -906,7 +906,8 @@ static int machine_constraints_voltage(struct regulator_dev *rdev, /* do we need to apply the constraint voltage */ if (rdev->constraints->apply_uV && - rdev->constraints->min_uV == rdev->constraints->max_uV) { + rdev->constraints->min_uV && rdev->constraints->max_uV) { + int target_min, target_max; int current_uV = _regulator_get_voltage(rdev); if (current_uV < 0) { rdev_err(rdev, @@ -914,15 +915,32 @@ static int machine_constraints_voltage(struct regulator_dev *rdev, current_uV); return current_uV; } - if (current_uV < rdev->constraints->min_uV || - current_uV > rdev->constraints->max_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->constraints->min_uV) { + target_min = rdev->constraints->min_uV; + target_max = rdev->constraints->min_uV; + } + + if (current_uV > rdev->constraints->max_uV) { + target_min = rdev->constraints->max_uV; + target_max = rdev->constraints->max_uV; + } + + if (target_min != current_uV || target_max != current_uV) { ret = _regulator_do_set_voltage( - rdev, rdev->constraints->min_uV, - rdev->constraints->max_uV); + rdev, target_min, target_max); if (ret < 0) { rdev_err(rdev, - "failed to apply %duV constraint(%d)\n", - rdev->constraints->min_uV, ret); + "failed to apply %d-%duV constraint(%d)\n", + target_min, target_max, ret); return ret; } } diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index d2ddefaaddaf..f45106a44635 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -43,7 +43,7 @@ static void of_get_regulation_constraints(struct device_node *np, constraints->max_uV = pval; /* Voltage change possible? */ - if (constraints->min_uV != constraints->max_uV) { + if (constraints->min_uV && constraints->max_uV) { constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE; constraints->apply_uV = true; } -- 2.30.2