[PATCH 5.10.y-cip 02/13] regulator: core: Add helper for allow HW access to enable/disable regulator

Biju Das
2024-07-29T15:35:19Z

commit 1cb7d29157603561af4c38535e936850ceb99f0f upstream.

Add a helper function that allow regulator consumers to allow low-level
HW access, in order to enable/disable regulator in atomic context.

The use-case for RZ/G2L SoC is to enable VBUS selection register based
on vbus detection that happens in interrupt context.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://patch.msgid.link/20240616105402.45211-4-biju.das.jz@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
Documentation/power/regulator/consumer.rst | 6 +++++
drivers/regulator/core.c | 28 ++++++++++++++++++++++
include/linux/regulator/consumer.h | 7 ++++++
3 files changed, 41 insertions(+)

diff --git a/Documentation/power/regulator/consumer.rst b/Documentation/power/regulator/consumer.rst
index 0cd8cc1275a7..ebc4c8076711 100644
--- a/Documentation/power/regulator/consumer.rst
+++ b/Documentation/power/regulator/consumer.rst
@@ -227,3 +227,9 @@ directly written to the voltage selector register, use::

int regulator_list_hardware_vsel(struct regulator *regulator,
unsigned selector);
+
+To access the hardware for enabling/disabling the regulator, consumers must
+use regulator_get_exclusive(), as it can't work if there's more than one
+consumer. To enable/disable regulator use::
+
+ int regulator_hardware_enable(struct regulator *regulator, bool enable);
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 7082cffdd10e..c5b6979b2560 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3244,6 +3244,34 @@ int regulator_list_hardware_vsel(struct regulator *regulator,
}
EXPORT_SYMBOL_GPL(regulator_list_hardware_vsel);

+/**
+ * regulator_hardware_enable - access the HW for enable/disable regulator
+ * @regulator: regulator source
+ * @enable: true for enable, false for disable
+ *
+ * Request that the regulator be enabled/disabled with the regulator output at
+ * the predefined voltage or current value.
+ *
+ * On success 0 is returned, otherwise a negative errno is returned.
+ */
+int regulator_hardware_enable(struct regulator *regulator, bool enable)
+{
+ struct regulator_dev *rdev = regulator->rdev;
+ const struct regulator_ops *ops = rdev->desc->ops;
+ int ret = -EOPNOTSUPP;
+
+ if (!rdev->exclusive || !ops || !ops->enable || !ops->disable)
+ return ret;
+
+ if (enable)
+ ret = ops->enable(rdev);
+ else
+ ret = ops->disable(rdev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_hardware_enable);
+
/**
* regulator_get_linear_step - return the voltage step size between VSEL values
* @regulator: regulator source
diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index 20e84a84fb77..42da800f86ff 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -268,6 +268,7 @@ int regulator_get_hardware_vsel_register(struct regulator *regulator,
unsigned *vsel_mask);
int regulator_list_hardware_vsel(struct regulator *regulator,
unsigned selector);
+int regulator_hardware_enable(struct regulator *regulator, bool enable);

/* regulator notifier block */
int regulator_register_notifier(struct regulator *regulator,
@@ -565,6 +566,12 @@ static inline int regulator_list_hardware_vsel(struct regulator *regulator,
return -EOPNOTSUPP;
}

+static inline int regulator_hardware_enable(struct regulator *regulator,
+ bool enable)
+{
+ return -EOPNOTSUPP;
+}
+
static inline int regulator_register_notifier(struct regulator *regulator,
struct notifier_block *nb)
{
--
2.43.0