[PATCH v4 2/4] regulator: qcom-rpmh: Add support for regulator-off-on-delay-us

[Jishnu Prakash <jishnu.prakash@oss.qualcomm.com>]

From: Saikiran <bjsaikiran@gmail.com>

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>
Signed-off-by: Jishnu Prakash <jishnu.prakash@oss.qualcomm.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 25c14de3cd8b..4773034b5d42 100644
--- a/drivers/regulator/qcom-rpmh-regulator.c
+++ b/drivers/regulator/qcom-rpmh-regulator.c
@@ -552,6 +552,9 @@ 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;

-- 
2.43.0