[PATCH v3 1/2] regulator: DT: Add properties for asymmetric settling times

[PATCH v3 1/2] regulator: DT: Add properties for asymmetric settling times

[Matthias Kaehlcke]

Some regulators have different settling times for voltage increases and
decreases. Add DT properties to define separate settling times for up-
and downward voltage changes.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
---
Changes in v3:
- none

 Documentation/devicetree/bindings/regulator/regulator.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt
index d18edb075e1c..378f6dc8b8bd 100644
--- a/Documentation/devicetree/bindings/regulator/regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/regulator.txt
@@ -24,6 +24,14 @@ Optional properties:
 - regulator-settling-time-us: Settling time, in microseconds, for voltage
   change if regulator have the constant time for any level voltage change.
   This is useful when regulator have exponential voltage change.
+- regulator-settling-time-up-us: Settling time, in microseconds, for voltage
+  increase if the regulator needs a constant time to settle after voltage
+  increases of any level. This is useful for regulators with exponential
+  voltage changes.
+- regulator-settling-time-down-us: Settling time, in microseconds, for voltage
+  decrease if the regulator needs a constant time to settle after voltage
+  decreases of any level. This is useful for regulators with exponential
+  voltage changes.
 - regulator-soft-start: Enable soft start so that voltage ramps slowly
 - regulator-state-mem sub-root node for Suspend-to-RAM mode
   : suspend to memory, the device goes to sleep, but all data stored in memory,
-- 
2.13.0.303.g4ebf302169-goog

[PATCH v3 2/2] regulator: Allow for asymmetric settling times

[Matthias Kaehlcke]

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@chromium.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
---
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

Applied "regulator: Allow for asymmetric settling times" to the regulator tree

[Mark Brown]

The patch

   regulator: Allow for asymmetric settling times

has been applied to the regulator tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 3ffad468cf1d9825b425733941bdad0d8d20e795 Mon Sep 17 00:00:00 2001
From: Matthias Kaehlcke <mka@chromium.org>
Date: Tue, 16 May 2017 11:43:43 -0700
Subject: [PATCH] regulator: Allow for asymmetric settling times

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@chromium.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 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;
-- 
2.11.0