2012-06-09 11:10:58

by Yadwinder Singh Brar

[permalink] [raw]
Subject: [PATCH v2 1/2] regulator: core: Add regulator_set_voltage_time_sel to calculate ramp delay.

This patch adds regulator_set_voltage_time_sel(), to move into core, the
commonly used code by drivers to provide the .set_voltage_time_sel callback.
It will also allow us to configure different ramp delay for different
regulators easily.

Signed-off-by: Yadwinder Singh Brar <[email protected]>
---
drivers/regulator/core.c | 24 ++++++++++++++++++++++++
include/linux/regulator/driver.h | 5 +++++
2 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 876f5fc..f4c056a 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2289,6 +2289,30 @@ int regulator_set_voltage_time(struct regulator *regulator,
EXPORT_SYMBOL_GPL(regulator_set_voltage_time);

/**
+ *regulator_set_voltage_time_sel - get raise/fall time
+ * @regulator: regulator source
+ * @old_selector: selector for starting voltage
+ * @new_selector: selector for target voltage
+ *
+ * Provided with the starting and target voltage selectors, this function
+ * returns time in microseconds required to rise or fall to this new voltage
+ *
+ * Drivers providing uV_step in their regulator_desc and ramp_delay in
+ * regulation_constraints can use this as their set_voltage_time_sel()
+ * operation.
+ */
+int regulator_set_voltage_time_sel(struct regulator_dev *rdev,
+ unsigned int old_selector,
+ unsigned int new_selector)
+{
+ if (rdev->desc->ramp_delay && rdev->desc->uV_step)
+ return DIV_ROUND_UP(rdev->desc->uV_step *
+ abs(new_selector - old_selector),
+ rdev->desc->ramp_delay) * 1000;
+ return 0;
+}
+
+/**
* regulator_sync_voltage - re-apply last regulator output voltage
* @regulator: regulator source
*
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 8022638..ae5c253 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -170,6 +170,7 @@ enum regulator_type {
*
* @min_uV: Voltage given by the lowest selector (if linear mapping)
* @uV_step: Voltage increase with each selector (if linear mapping)
+ * @ramp_delay: Time to settle down after voltage change (unit: mV/us)
* @volt_table: Voltage mapping table (if table based mapping)
*
* @vsel_reg: Register for selector when using regulator_regmap_X_voltage_
@@ -189,6 +190,7 @@ struct regulator_desc {

unsigned int min_uV;
unsigned int uV_step;
+ unsigned int ramp_delay;

const unsigned int *volt_table;

@@ -285,6 +287,9 @@ int regulator_set_voltage_sel_regmap(struct regulator_dev *rdev, unsigned sel);
int regulator_is_enabled_regmap(struct regulator_dev *rdev);
int regulator_enable_regmap(struct regulator_dev *rdev);
int regulator_disable_regmap(struct regulator_dev *rdev);
+int regulator_set_voltage_time_sel(struct regulator_dev *rdev,
+ unsigned int old_selector,
+ unsigned int new_selector);

void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data);

--
1.7.0.4


2012-06-09 11:11:06

by Yadwinder Singh Brar

[permalink] [raw]
Subject: [PATCH v2 2/2] regulator: Parse ramp_delay in while parsing DT for regulators.

For some hardwares ramp_delay for BUCKs is a configurable parameter which can
be configured through DT.This patch adds support for parsing ramp_delay also
while parsing DT for regulators.

Signed-off-by: Yadwinder Singh Brar <[email protected]>
---
.../devicetree/bindings/regulator/regulator.txt | 1 +
drivers/regulator/of_regulator.c | 6 ++++++
include/linux/regulator/machine.h | 2 ++
3 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt
index 5b7a408..d0a7b12 100644
--- a/Documentation/devicetree/bindings/regulator/regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/regulator.txt
@@ -10,6 +10,7 @@ Optional properties:
- regulator-always-on: boolean, regulator should never be disabled
- regulator-boot-on: bootloader/firmware enabled regulator
- <name>-supply: phandle to the parent supply/regulator node
+- regulator-ramp-delay: ramp delay for regulator(in mV/uS)

Example:

diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 56593b7..8b9cb53 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -74,6 +74,7 @@ struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
struct device_node *node)
{
struct regulator_init_data *init_data;
+ const __be32 *ramp_delay;

if (!node)
return NULL;
@@ -83,6 +84,11 @@ struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
return NULL; /* Out of memory? */

of_get_regulation_constraints(node, &init_data);
+
+ ramp_delay = of_get_property(node, "regulator-ramp-delay", NULL);
+ if (ramp_delay)
+ init_data->ramp_delay = be32_to_cpu(*ramp_delay);
+
return init_data;
}
EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index b021084..bb29a6b 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -177,6 +177,8 @@ struct regulator_init_data {
int num_consumer_supplies;
struct regulator_consumer_supply *consumer_supplies;

+ int ramp_delay; /* unit:mV/us */
+
/* optional regulator machine specific init */
int (*regulator_init)(void *driver_data);
void *driver_data; /* core does not touch this */
--
1.7.0.4

2012-06-11 04:08:15

by Mark Brown

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] regulator: Parse ramp_delay in while parsing DT for regulators.

On Sat, Jun 09, 2012 at 04:40:39PM +0530, Yadwinder Singh Brar wrote:
> For some hardwares ramp_delay for BUCKs is a configurable parameter which can
> be configured through DT.This patch adds support for parsing ramp_delay also
> while parsing DT for regulators.

I think this is a sensible idea but I think that we should go further,
move the value into the constraints and add set and get operations too
so that all the device needs to do is provide the operations (ideally
just the translation functions for regmap using devices).


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