Some regulators have different settling times for voltage increases and
decreases. To avoid a time penalty on the faster transition allow for
different settings for up- and downward transitions.
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Acked-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
---
Changes in v3:
- Added check for conflicting settling time configurations. A warning is
printed if up/down settling times are specified at the same time as
the more general ("symmetrical") setting. In case of conflicts the
up/down times are ignored and 'regulator-settling-time-us' is used.
drivers/regulator/core.c | 6 ++++++
drivers/regulator/of_regulator.c | 19 +++++++++++++++++++
include/linux/regulator/machine.h | 6 ++++++
3 files changed, 31 insertions(+)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index c0d9ae8d0860..919b7f178209 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2767,6 +2767,12 @@ static int _regulator_set_voltage_time(struct regulator_dev *rdev,
ramp_delay = rdev->desc->ramp_delay;
else if (rdev->constraints->settling_time)
return rdev->constraints->settling_time;
+ else if (rdev->constraints->settling_time_up &&
+ (new_uV > old_uV))
+ return rdev->constraints->settling_time_up;
+ else if (rdev->constraints->settling_time_down &&
+ (new_uV < old_uV))
+ return rdev->constraints->settling_time_down;
if (ramp_delay == 0) {
rdev_dbg(rdev, "ramp_delay not set\n");
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 09d677d5d3f0..96bf75458da5 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -90,6 +90,25 @@ static void of_get_regulation_constraints(struct device_node *np,
if (!ret)
constraints->settling_time = pval;
+ ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
+ if (!ret)
+ constraints->settling_time_up = pval;
+ if (constraints->settling_time_up && constraints->settling_time) {
+ pr_warn("%s: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
+ np->name);
+ constraints->settling_time_up = 0;
+ }
+
+ ret = of_property_read_u32(np, "regulator-settling-time-down-us",
+ &pval);
+ if (!ret)
+ constraints->settling_time_down = pval;
+ if (constraints->settling_time_down && constraints->settling_time) {
+ pr_warn("%s: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
+ np->name);
+ constraints->settling_time_down = 0;
+ }
+
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 117699d1f7df..9cd4fef37203 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -110,6 +110,10 @@ struct regulator_state {
* @ramp_delay: Time to settle down after voltage change (unit: uV/us)
* @settling_time: Time to settle down after voltage change when voltage
* change is non-linear (unit: microseconds).
+ * @settling_time_up: Time to settle down after voltage increase when voltage
+ * change is non-linear (unit: microseconds).
+ * @settling_time_down : Time to settle down after voltage decrease when
+ * voltage change is non-linear (unit: microseconds).
* @active_discharge: Enable/disable active discharge. The enum
* regulator_active_discharge values are used for
* initialisation.
@@ -152,6 +156,8 @@ struct regulation_constraints {
unsigned int ramp_delay;
unsigned int settling_time;
+ unsigned int settling_time_up;
+ unsigned int settling_time_down;
unsigned int enable_time;
unsigned int active_discharge;
--
2.13.0.303.g4ebf302169-goog
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