[RFC PATCH 2/5] regulator: Add devm helpers for get and enable

[Matti Vaittinen]

A few regulator consumer drivers seem to be just getting a regulator,
enabling it and registering a devm-action to disable the regulator at
the driver detach and then forget about it.

We can simplify this a bit by adding a devm-helper for this pattern.
Add devm_regulator_get_enable() and devm_regulator_get_enable_optional()

Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
Link: https://lore.kernel.org/r/ed7b8841193bb9749d426f3cb3b199c9460794cd.1660292316.git.mazziesaccount@xxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---

Please note - this patch is already in Mark's tree. It's here just to
allow compilation of the series on top of v6.0-rc4

 drivers/regulator/devres.c         | 105 +++++++++++++++++++++++++++++
 include/linux/regulator/consumer.h |  14 ++++
 2 files changed, 119 insertions(+)

diff --git a/drivers/regulator/devres.c b/drivers/regulator/devres.c
index 3cb3eb49ad8a..3265e75e97ab 100644
--- a/drivers/regulator/devres.c
+++ b/drivers/regulator/devres.c
@@ -253,6 +253,111 @@ int devm_regulator_bulk_get_const(struct device *dev, int num_consumers,
 }
 EXPORT_SYMBOL_GPL(devm_regulator_bulk_get_const);
 
+static int devm_regulator_bulk_match(struct device *dev, void *res,
+				     void *data)
+{
+	struct regulator_bulk_devres *match = res;
+	struct regulator_bulk_data *target = data;
+
+	/*
+	 * We check the put uses same consumer list as the get did.
+	 * We _could_ scan all entries in consumer array and check the
+	 * regulators match but ATM I don't see the need. We can change this
+	 * later if needed.
+	 */
+	return match->consumers == target;
+}
+
+/**
+ * devm_regulator_bulk_put - Resource managed regulator_bulk_put()
+ * @consumers: consumers to free
+ *
+ * Deallocate regulators allocated with devm_regulator_bulk_get(). Normally
+ * this function will not need to be called and the resource management
+ * code will ensure that the resource is freed.
+ */
+void devm_regulator_bulk_put(struct regulator_bulk_data *consumers)
+{
+	int rc;
+	struct regulator *regulator = consumers[0].consumer;
+
+	rc = devres_release(regulator->dev, devm_regulator_bulk_release,
+			    devm_regulator_bulk_match, consumers);
+	if (rc != 0)
+		WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_regulator_bulk_put);
+
+static void devm_regulator_bulk_disable(void *res)
+{
+	struct regulator_bulk_devres *devres = res;
+	int i;
+
+	for (i = 0; i < devres->num_consumers; i++)
+		regulator_disable(devres->consumers[i].consumer);
+}
+
+/**
+ * devm_regulator_bulk_get_enable - managed get'n enable multiple regulators
+ *
+ * @dev:           device to supply
+ * @num_consumers: number of consumers to register
+ * @id:            list of supply names or regulator IDs
+ *
+ * @return 0 on success, an errno on failure.
+ *
+ * This helper function allows drivers to get several regulator
+ * consumers in one operation with management, the regulators will
+ * automatically be freed when the device is unbound.  If any of the
+ * regulators cannot be acquired then any regulators that were
+ * allocated will be freed before returning to the caller.
+ */
+int devm_regulator_bulk_get_enable(struct device *dev, int num_consumers,
+				   const char * const *id)
+{
+	struct regulator_bulk_devres *devres;
+	struct regulator_bulk_data *consumers;
+	int i, ret;
+
+	devres = devm_kmalloc(dev, sizeof(*devres), GFP_KERNEL);
+	if (!devres)
+		return -ENOMEM;
+
+	devres->consumers = devm_kcalloc(dev, num_consumers, sizeof(*consumers),
+					 GFP_KERNEL);
+	consumers = devres->consumers;
+	if (!consumers)
+		return -ENOMEM;
+
+	devres->num_consumers = num_consumers;
+
+	for (i = 0; i < num_consumers; i++)
+		consumers[i].supply = id[i];
+
+	ret = devm_regulator_bulk_get(dev, num_consumers, consumers);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < num_consumers; i++) {
+		ret = regulator_enable(consumers[i].consumer);
+		if (ret)
+			goto unwind;
+	}
+
+	ret = devm_add_action(dev, devm_regulator_bulk_disable, devres);
+	if (!ret)
+		return 0;
+
+unwind:
+	while (--i >= 0)
+		regulator_disable(consumers[i].consumer);
+
+	devm_regulator_bulk_put(consumers);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_regulator_bulk_get_enable);
+
 static void devm_rdev_release(struct device *dev, void *res)
 {
 	regulator_unregister(*(struct regulator_dev **)res);
diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index 8e6cf65851b0..ee3b4a014611 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -246,12 +246,15 @@ int __must_check regulator_bulk_get(struct device *dev, int num_consumers,
 				    struct regulator_bulk_data *consumers);
 int __must_check devm_regulator_bulk_get(struct device *dev, int num_consumers,
 					 struct regulator_bulk_data *consumers);
+void devm_regulator_bulk_put(struct regulator_bulk_data *consumers);
 int __must_check devm_regulator_bulk_get_const(
 	struct device *dev, int num_consumers,
 	const struct regulator_bulk_data *in_consumers,
 	struct regulator_bulk_data **out_consumers);
 int __must_check regulator_bulk_enable(int num_consumers,
 				       struct regulator_bulk_data *consumers);
+int devm_regulator_bulk_get_enable(struct device *dev, int num_consumers,
+				   const char * const *id);
 int regulator_bulk_disable(int num_consumers,
 			   struct regulator_bulk_data *consumers);
 int regulator_bulk_force_disable(int num_consumers,
@@ -388,6 +391,10 @@ static inline void devm_regulator_put(struct regulator *regulator)
 {
 }
 
+static inline void devm_regulator_bulk_put(struct regulator_bulk_data *consumers)
+{
+}
+
 static inline int regulator_register_supply_alias(struct device *dev,
 						  const char *id,
 						  struct device *alias_dev,
@@ -478,6 +485,13 @@ static inline int regulator_bulk_enable(int num_consumers,
 	return 0;
 }
 
+static inline int devm_regulator_bulk_get_enable(struct device *dev,
+						 int num_consumers,
+						 const char * const *id)
+{
+	return 0;
+}
+
 static inline int regulator_bulk_disable(int num_consumers,
 					 struct regulator_bulk_data *consumers)
 {
-- 
2.37.1


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]

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