regulator: Add ramp_delay configuration to constraints

For some hardwares ramp_delay for BUCKs is a configurable parameter which can
be configured through DT or board file.This patch adds ramp_delay to regulator
constraints and allow user to configure it for regulators which supports this
feature, through DT or board file. It will provide two ways of setting the
ramp_delay for a regulator:
	First, by setting it as constraints in board file(for configurable
regulators) and set_machine_constraints() will take care of setting it on
hardware by calling(the provided) .set_ramp_delay() operation(callback).
	Second, by setting it as data in regulator_desc(as fixed/default
ramp_delay rate) for a regulator in driver.

regulator_set_voltage_time_sel() will give preference to
constraints->ramp_delay while reading ramp_delay rate for regulator. Similarly
users should also take care accordingly while refering ramp_delay rate(in case
of implementing their private .set_voltage_time_sel() callbacks for different
regulators).

[Rewrote subject for 80 columns -- broonie]

Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 56593b75168a..e2a731079066 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -20,7 +20,7 @@ static void of_get_regulation_constraints(struct device_node *np,
                                         struct regulator_init_data **init_data)
 {
         const __be32 *min_uV, *max_uV, *uV_offset;
-        const __be32 *min_uA, *max_uA;
+        const __be32 *min_uA, *max_uA, *ramp_delay;
         struct regulation_constraints *constraints = &(*init_data)->constraints;
 
         constraints->name = of_get_property(np, "regulator-name", NULL);
@@ -60,6 +60,10 @@ static void of_get_regulation_constraints(struct device_node *np,
                 constraints->always_on = true;
         else /* status change should be possible if not always on. */
                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
+
+        ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL);
+        if (ramp_delay)
+                constraints->min_uV = be32_to_cpu(*ramp_delay);
 }
 
 /**