regulator: Add pull down support

Some regulators need to be configured to pull down a resistor
when the regulator is disabled. Add an op (set_pull_down) and a
DT property + constraint to support this.

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

2 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index fffa688ac3a7..76144a337ff7 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -121,6 +121,9 @@ struct regulator_linear_range {
  * @set_suspend_mode: Set the operating mode for the regulator when the
  *                    system is suspended.
  *
+ * @set_pull_down: Configure the regulator to pull down when the regulator
+ *                 is disabled.
+ *
  * This struct describes regulator operations which can be implemented by
  * regulator chip drivers.
  */
@@ -187,6 +190,8 @@ struct regulator_ops {
 
         /* set regulator suspend operating mode (defined in consumer.h) */
         int (*set_suspend_mode) (struct regulator_dev *, unsigned int mode);
+
+        int (*set_pull_down) (struct regulator_dev *);
 };
 
 /*
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index 01526559c8c3..8ffb0619a03c 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -87,6 +87,7 @@ struct regulator_state {
  *           applied.
  * @apply_uV: Apply the voltage constraint when initialising.
  * @ramp_disable: Disable ramp delay when initialising or when setting voltage.
+ * @pull_down: Enable pull down when regulator is disabled.
  *
  * @input_uV: Input voltage for regulator when supplied by another regulator.
  *
@@ -141,6 +142,7 @@ struct regulation_constraints {
         unsigned boot_on:1;     /* bootloader/firmware enabled regulator */
         unsigned apply_uV:1;    /* apply uV constraint if min == max */
         unsigned ramp_disable:1; /* disable ramp delay */
+        unsigned pull_down:1;   /* pull down resistor when regulator off */
 };
 
 /**