[PATCH] regulator: core: set current constraints while setting machine constraints

[PATCH] regulator: core: set current constraints while setting machine constraints

[Laxman Dewangan]

Machine constraints is configured during regulator register. If current
constraints are provided through machine constraints then it is observed
that sometime the current configured on rail is out of range what machine
constraint has.

Set the current constraints when setting machine constraints to make
sure that rail's current is within the range of given machine constraints.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/regulator/core.c |   38 ++++++++++++++++++++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index b698e2b..617e337 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -904,6 +904,40 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
 	return 0;
 }
 
+static int machine_constraints_current(struct regulator_dev *rdev,
+	struct regulation_constraints *constraints)
+{
+	int current_uA;
+	int ret;
+
+	if (!rdev->desc->ops->set_current_limit ||
+			!rdev->desc->ops->get_current_limit)
+		return 0;
+
+	if (!rdev->constraints->min_uA && !rdev->constraints->max_uA)
+		return 0;
+
+	if (rdev->constraints->min_uA > rdev->constraints->max_uA) {
+		rdev_err(rdev, "Current constraint is invalid\n");
+		return -EINVAL;
+	}
+
+	/* Set regulator current in constraint range */
+	current_uA = rdev->desc->ops->get_current_limit(rdev);
+	if (current_uA < rdev->constraints->min_uA ||
+			current_uA > rdev->constraints->max_uA) {
+		ret = rdev->desc->ops->set_current_limit(rdev,
+				rdev->constraints->min_uA,
+				rdev->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
@@ -934,6 +968,10 @@ 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);
-- 
1.7.1.1

Re: [PATCH] regulator: core: set current constraints while setting machine constraints

[Mark Brown]

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On Thu, Sep 19, 2013 at 08:16:28PM +0530, Laxman Dewangan wrote:

> +	if (!rdev->desc->ops->set_current_limit ||
> +			!rdev->desc->ops->get_current_limit)
> +		return 0;
> +

The indentation here is odd and we probably ought to complain if someone
tries to set a current constarint on a regulator that doesn't support
the operation, if only to avoid surprises later on when the limits don't
take effect.

> +	current_uA = rdev->desc->ops->get_current_limit(rdev);
> +	if (current_uA < rdev->constraints->min_uA ||
> +			current_uA > rdev->constraints->max_uA) {
> +		ret = rdev->desc->ops->set_current_limit(rdev,
> +				rdev->constraints->min_uA,
> +				rdev->constraints->max_uA);
> +		if (ret < 0) {
> +			rdev_err(rdev,
> +				"Failed to set current constraint, %d\n", ret);
> +			return ret;
> +		}

Why is this conditional on the existing setting?  Just apply the
constraint.

> +	}
> +	return 0;

Missing blank.

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