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-rw-r--r--Documentation/devicetree/bindings/regulator/regulator.txt5
-rw-r--r--drivers/regulator/core.c76
-rw-r--r--drivers/regulator/of_regulator.c6
-rw-r--r--include/linux/regulator/machine.h2
4 files changed, 83 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt
index 2bd8f0978765..e2c7f1e7251a 100644
--- a/Documentation/devicetree/bindings/regulator/regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/regulator.txt
@@ -14,6 +14,11 @@ Optional properties:
- regulator-ramp-delay: ramp delay for regulator(in uV/uS)
For hardwares which support disabling ramp rate, it should be explicitly
intialised to zero (regulator-ramp-delay = <0>) for disabling ramp delay.
+- regulator-enable-ramp-delay: The time taken, in microseconds, for the supply
+ rail to reach the target voltage, plus/minus whatever tolerance the board
+ design requires. This property describes the total system ramp time
+ required due to the combination of internal ramping of the regulator itself,
+ and board design issues such as trace capacitance and load on the supply.
Deprecated properties:
- regulator-compatible: If a regulator chip contains multiple
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 16427de56ce8..916cadf45279 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -919,6 +919,36 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
return 0;
}
+static int machine_constraints_current(struct regulator_dev *rdev,
+ struct regulation_constraints *constraints)
+{
+ struct regulator_ops *ops = rdev->desc->ops;
+ int ret;
+
+ if (!constraints->min_uA && !constraints->max_uA)
+ return 0;
+
+ if (constraints->min_uA > constraints->max_uA) {
+ rdev_err(rdev, "Invalid current constraints\n");
+ return -EINVAL;
+ }
+
+ if (!ops->set_current_limit || !ops->get_current_limit) {
+ rdev_warn(rdev, "Operation of current configuration missing\n");
+ return 0;
+ }
+
+ /* Set regulator current in constraints range */
+ ret = ops->set_current_limit(rdev, constraints->min_uA,
+ constraints->max_uA);
+ if (ret < 0) {
+ rdev_err(rdev, "Failed to set current constraint, %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
/**
* set_machine_constraints - sets regulator constraints
* @rdev: regulator source
@@ -949,6 +979,10 @@ static int set_machine_constraints(struct regulator_dev *rdev,
if (ret != 0)
goto out;
+ ret = machine_constraints_current(rdev, rdev->constraints);
+ if (ret != 0)
+ goto out;
+
/* do we need to setup our suspend state */
if (rdev->constraints->initial_state) {
ret = suspend_prepare(rdev, rdev->constraints->initial_state);
@@ -1182,6 +1216,8 @@ overflow_err:
static int _regulator_get_enable_time(struct regulator_dev *rdev)
{
+ if (rdev->constraints && rdev->constraints->enable_time)
+ return rdev->constraints->enable_time;
if (!rdev->desc->ops->enable_time)
return rdev->desc->enable_time;
return rdev->desc->ops->enable_time(rdev);
@@ -1276,7 +1312,7 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
if (id == NULL) {
pr_err("get() with no identifier\n");
- return regulator;
+ return ERR_PTR(-EINVAL);
}
if (dev)
@@ -1733,11 +1769,39 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
* together. */
trace_regulator_enable_delay(rdev_get_name(rdev));
- if (delay >= 1000) {
- mdelay(delay / 1000);
- udelay(delay % 1000);
- } else if (delay) {
- udelay(delay);
+ /*
+ * Delay for the requested amount of time as per the guidelines in:
+ *
+ * Documentation/timers/timers-howto.txt
+ *
+ * The assumption here is that regulators will never be enabled in
+ * atomic context and therefore sleeping functions can be used.
+ */
+ if (delay) {
+ unsigned int ms = delay / 1000;
+ unsigned int us = delay % 1000;
+
+ if (ms > 0) {
+ /*
+ * For small enough values, handle super-millisecond
+ * delays in the usleep_range() call below.
+ */
+ if (ms < 20)
+ us += ms * 1000;
+ else
+ msleep(ms);
+ }
+
+ /*
+ * Give the scheduler some room to coalesce with any other
+ * wakeup sources. For delays shorter than 10 us, don't even
+ * bother setting up high-resolution timers and just busy-
+ * loop.
+ */
+ if (us >= 10)
+ usleep_range(us, us + 100);
+ else
+ udelay(us);
}
trace_regulator_enable_complete(rdev_get_name(rdev));
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 7827384680d6..ea4f36f2cbe2 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -23,6 +23,8 @@ static void of_get_regulation_constraints(struct device_node *np,
const __be32 *min_uA, *max_uA, *ramp_delay;
struct property *prop;
struct regulation_constraints *constraints = &(*init_data)->constraints;
+ int ret;
+ u32 pval;
constraints->name = of_get_property(np, "regulator-name", NULL);
@@ -73,6 +75,10 @@ static void of_get_regulation_constraints(struct device_node *np,
else
constraints->ramp_disable = true;
}
+
+ 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 999b20ce06cf..8108751acb86 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -95,6 +95,7 @@ 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)
+ * @enable_time: Turn-on time of the rails (unit: microseconds)
*/
struct regulation_constraints {
@@ -129,6 +130,7 @@ struct regulation_constraints {
unsigned int initial_mode;
unsigned int ramp_delay;
+ unsigned int enable_time;
/* constraint flags */
unsigned always_on:1; /* regulator never off when system is on */