From 00c877c69ba315d6c565a4df51c71b11e82cdeb8 Mon Sep 17 00:00:00 2001 From: Laxman Dewangan Date: Wed, 18 Sep 2013 18:18:02 +0530 Subject: [PATCH] regulator: core: add support for configuring turn-on time through constraints The turn-on time of the regulator depends on the regulator device's electrical characteristics. Sometimes regulator turn-on time also depends on the capacitive load on the given platform and it can be more than the datasheet value. The driver provides the enable-time as per datasheet. Add support for configure the enable ramp time through regulator constraints so that regulator core can take this value for enable time for that regulator. Signed-off-by: Laxman Dewangan Acked-by: Stephen Warren Signed-off-by: Mark Brown --- Documentation/devicetree/bindings/regulator/regulator.txt | 5 +++++ drivers/regulator/core.c | 2 ++ drivers/regulator/of_regulator.c | 6 ++++++ include/linux/regulator/machine.h | 2 ++ 4 files changed, 15 insertions(+) diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt index 2bd8f0978765..e2c7f1e7251a 100644 --- a/Documentation/devicetree/bindings/regulator/regulator.txt +++ b/Documentation/devicetree/bindings/regulator/regulator.txt @@ -14,6 +14,11 @@ Optional properties: - regulator-ramp-delay: ramp delay for regulator(in uV/uS) For hardwares which support disabling ramp rate, it should be explicitly intialised to zero (regulator-ramp-delay = <0>) for disabling ramp delay. +- regulator-enable-ramp-delay: The time taken, in microseconds, for the supply + rail to reach the target voltage, plus/minus whatever tolerance the board + design requires. This property describes the total system ramp time + required due to the combination of internal ramping of the regulator itself, + and board design issues such as trace capacitance and load on the supply. Deprecated properties: - regulator-compatible: If a regulator chip contains multiple diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index a01b8b3b70ca..5217c1964c32 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1186,6 +1186,8 @@ overflow_err: static int _regulator_get_enable_time(struct regulator_dev *rdev) { + if (rdev->constraints && rdev->constraints->enable_time) + return rdev->constraints->enable_time; if (!rdev->desc->ops->enable_time) return rdev->desc->enable_time; return rdev->desc->ops->enable_time(rdev); diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index 7827384680d6..ea4f36f2cbe2 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -23,6 +23,8 @@ static void of_get_regulation_constraints(struct device_node *np, const __be32 *min_uA, *max_uA, *ramp_delay; struct property *prop; struct regulation_constraints *constraints = &(*init_data)->constraints; + int ret; + u32 pval; constraints->name = of_get_property(np, "regulator-name", NULL); @@ -73,6 +75,10 @@ static void of_get_regulation_constraints(struct device_node *np, else constraints->ramp_disable = true; } + + ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval); + if (!ret) + constraints->enable_time = pval; } /** diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h index 999b20ce06cf..8108751acb86 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -95,6 +95,7 @@ struct regulator_state { * @initial_state: Suspend state to set by default. * @initial_mode: Mode to set at startup. * @ramp_delay: Time to settle down after voltage change (unit: uV/us) + * @enable_time: Turn-on time of the rails (unit: microseconds) */ struct regulation_constraints { @@ -129,6 +130,7 @@ struct regulation_constraints { unsigned int initial_mode; unsigned int ramp_delay; + unsigned int enable_time; /* constraint flags */ unsigned always_on:1; /* regulator never off when system is on */ -- 2.39.5