The core regulator framework supports enforcing a physical off-time via
standard properties, but the `qcom-rpmh-regulator` driver currently ignores
them.
The issue is platform-specific: The Lenovo Yoga Slim 7x (Snapdragon X Elite)
has large bulk capacitors on the camera rails (LDO1, LDO3, LDO7). When these
regulators are disabled, the voltage decays very slowly (passive discharge).
If the rail is re-enabled before this discharge completes, the sensor
experiences a brownout and fails to initialize.
Add support for parsing the 'regulator-off-on-delay-us' property from
the device tree to enforce this physical constraint.
Signed-off-by: Saikiran <bjsaikiran@gmail.com>
---
drivers/regulator/qcom-rpmh-regulator.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/regulator/qcom-rpmh-regulator.c b/drivers/regulator/qcom-rpmh-regulator.c
index 6e4cb2871fca..aafba61551b3 100644
--- a/drivers/regulator/qcom-rpmh-regulator.c
+++ b/drivers/regulator/qcom-rpmh-regulator.c
@@ -503,6 +503,9 @@ static int rpmh_regulator_init_vreg(struct rpmh_vreg *vreg, struct device *dev,
vreg->always_wait_for_ack = of_property_read_bool(node,
"qcom,always-wait-for-ack");
+ of_property_read_u32(node, "regulator-off-on-delay-us",
+ &vreg->rdesc.off_on_delay);
+
vreg->rdesc.owner = THIS_MODULE;
vreg->rdesc.type = REGULATOR_VOLTAGE;
vreg->rdesc.ops = vreg->hw_data->ops;
--
2.51.0