[PATCH V3 2/2] regulator: Add settling time for non-linear voltage transition
From: Laxman Dewangan <hidden>
Date: 2016-11-23 11:19:49
Also in:
lkml
Subsystem:
the rest, voltage and current regulator framework · Maintainers:
Linus Torvalds, Liam Girdwood, Mark Brown
Some regulators (some PWM regulators) have the voltage transition
non-linear i.e. exponentially. On such cases, the settling time
for voltage transition can not be presented in the voltage-ramp-delay.
Add new property for non-linear voltage transition and handle this
in getting the voltage settling time.
Signed-off-by: Laxman Dewangan <redacted>
CC: Douglas Anderson <redacted>
CC: Aleksandr Frid <redacted>
---
This patch is continuation of discussion on patch
regulator: pwm: Fix regulator ramp delay for continuous mode
https://patchwork.kernel.org/patch/9216857/
where is it discussed to have separate property for PWM which has
exponential voltage transition.
Changes from V1:
- Use new DT property to finding that voltage ramp is exponential or
not and use flag for having fixed delay for all voltage change.
Changes from V2:
- Based on review comment from V1, make the settling time property
independent of the regulator-ramp-delay and move this to core
framework instead of handling in PWM regulator.
---
drivers/regulator/core.c | 2 ++
drivers/regulator/of_regulator.c | 4 ++++
include/linux/regulator/machine.h | 3 +++
3 files changed, 9 insertions(+)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 67426c0..06a2477 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c@@ -2752,6 +2752,8 @@ static int _regulator_set_voltage_time(struct regulator_dev *rdev, ramp_delay = rdev->constraints->ramp_delay; else if (rdev->desc->ramp_delay) ramp_delay = rdev->desc->ramp_delay; + else if (rdev->constraints->settling_time) + return rdev->constraints->settling_time; if (ramp_delay == 0) { rdev_warn(rdev, "ramp_delay not set\n");
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 4f613ec..09d677d 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c@@ -86,6 +86,10 @@ static void of_get_regulation_constraints(struct device_node *np, constraints->ramp_disable = true; } + ret = of_property_read_u32(np, "regulator-settling-time-us", &pval); + if (!ret) + constraints->settling_time = pval; + 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 ad3e515..598a493 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h@@ -108,6 +108,8 @@ 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) + * @settling_time: Time to settle down after voltage change when voltage + * change is non-linear (unit: microseconds). * @active_discharge: Enable/disable active discharge. The enum * regulator_active_discharge values are used for * initialisation.
@@ -149,6 +151,7 @@ struct regulation_constraints { unsigned int initial_mode; unsigned int ramp_delay; + unsigned int settling_time; unsigned int enable_time; unsigned int active_discharge;
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html