From 23c779b9f9161d6568d3b2fca06e70ad182c480c Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 11 Jun 2015 17:37:04 -0700 Subject: [PATCH] regulator: Add pull down support Some regulators need to be configured to pull down a resistor when the regulator is disabled. Add an op (set_pull_down) and a DT property + constraint to support this. Signed-off-by: Stephen Boyd Signed-off-by: Mark Brown --- Documentation/devicetree/bindings/regulator/regulator.txt | 1 + drivers/regulator/core.c | 8 ++++++++ drivers/regulator/of_regulator.c | 2 ++ include/linux/regulator/driver.h | 5 +++++ include/linux/regulator/machine.h | 2 ++ 5 files changed, 18 insertions(+) diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt index 553d2d0fe6d9..6c79fd70ab5a 100644 --- a/Documentation/devicetree/bindings/regulator/regulator.txt +++ b/Documentation/devicetree/bindings/regulator/regulator.txt @@ -39,6 +39,7 @@ Optional properties: documentation explains which values the regulator supports. - regulator-system-load: Load in uA present on regulator that is not captured by any consumer request. +- regulator-pull-down: Enable pull down resistor when the regulator is disabled. Deprecated properties: - regulator-compatible: If a regulator chip contains multiple diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index c8d5e2b05fdf..60fcfba52592 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1051,6 +1051,14 @@ static int set_machine_constraints(struct regulator_dev *rdev, } } + if (rdev->constraints->pull_down && ops->set_pull_down) { + ret = ops->set_pull_down(rdev); + if (ret < 0) { + rdev_err(rdev, "failed to set pull down\n"); + goto out; + } + } + print_constraints(rdev); return 0; out: diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index 482a86f90839..c3433db0acda 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -67,6 +67,8 @@ static void of_get_regulation_constraints(struct device_node *np, if (!constraints->always_on) /* status change should be possible. */ constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS; + constraints->pull_down = of_property_read_bool(np, "regulator-pull-down"); + if (of_property_read_bool(np, "regulator-allow-bypass")) constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS; diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index fffa688ac3a7..76144a337ff7 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -121,6 +121,9 @@ struct regulator_linear_range { * @set_suspend_mode: Set the operating mode for the regulator when the * system is suspended. * + * @set_pull_down: Configure the regulator to pull down when the regulator + * is disabled. + * * This struct describes regulator operations which can be implemented by * regulator chip drivers. */ @@ -187,6 +190,8 @@ struct regulator_ops { /* set regulator suspend operating mode (defined in consumer.h) */ int (*set_suspend_mode) (struct regulator_dev *, unsigned int mode); + + int (*set_pull_down) (struct regulator_dev *); }; /* diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h index 01526559c8c3..8ffb0619a03c 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -87,6 +87,7 @@ struct regulator_state { * applied. * @apply_uV: Apply the voltage constraint when initialising. * @ramp_disable: Disable ramp delay when initialising or when setting voltage. + * @pull_down: Enable pull down when regulator is disabled. * * @input_uV: Input voltage for regulator when supplied by another regulator. * @@ -141,6 +142,7 @@ struct regulation_constraints { unsigned boot_on:1; /* bootloader/firmware enabled regulator */ unsigned apply_uV:1; /* apply uV constraint if min == max */ unsigned ramp_disable:1; /* disable ramp delay */ + unsigned pull_down:1; /* pull down resistor when regulator off */ }; /** -- 2.45.2