regulator: Add over current protection (OCP) support

Some regulators can automatically shut down when they detect an
over current event. Add an op (set_over_current_protection) and a
DT property + constraint to support this capability.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

5 files changed, 15 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt
index db88feb28c03..24bd422cecd5 100644
--- a/Documentation/devicetree/bindings/regulator/regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/regulator.txt
@@ -42,6 +42,7 @@ Optional properties:
 - regulator-system-load: Load in uA present on regulator that is not captured by
   any consumer request.
 - regulator-pull-down: Enable pull down resistor when the regulator is disabled.
+- regulator-over-current-protection: Enable over current protection.
 
 Deprecated properties:
 - regulator-compatible: If a regulator chip contains multiple
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index c9f72019bd68..520413e2bca0 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1081,6 +1081,15 @@ static int set_machine_constraints(struct regulator_dev *rdev,
                 }
         }
 
+        if (rdev->constraints->over_current_protection
+                && ops->set_over_current_protection) {
+                ret = ops->set_over_current_protection(rdev);
+                if (ret < 0) {
+                        rdev_err(rdev, "failed to set over current protection\n");
+                        goto out;
+                }
+        }
+
         print_constraints(rdev);
         return 0;
 out:
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index b1c485b24ab2..250700c853bf 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -107,6 +107,9 @@ static void of_get_regulation_constraints(struct device_node *np,
         if (!of_property_read_u32(np, "regulator-system-load", &pval))
                 constraints->system_load = pval;
 
+        constraints->over_current_protection = of_property_read_bool(np,
+                                        "regulator-over-current-protection");
+
         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
                 switch (i) {
                 case PM_SUSPEND_MEM:
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 4db9fbe4889d..45932228cbf5 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -148,6 +148,7 @@ struct regulator_ops {
         int (*get_current_limit) (struct regulator_dev *);
 
         int (*set_input_current_limit) (struct regulator_dev *, int lim_uA);
+        int (*set_over_current_protection) (struct regulator_dev *);
 
         /* enable/disable regulator */
         int (*enable) (struct regulator_dev *);
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index b11be1260129..a1067d0b3991 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -147,6 +147,7 @@ struct regulation_constraints {
         unsigned ramp_disable:1; /* disable ramp delay */
         unsigned soft_start:1;  /* ramp voltage slowly */
         unsigned pull_down:1;   /* pull down resistor when regulator off */
+        unsigned over_current_protection:1; /* auto disable on over current */
 };
 
 /**