[PATCH v8 02/16] clk: Provide new devm_clk helpers for prepared and enabled clocks

Uwe Kleine-König
2022-03-14T14:18:12Z

When a driver keeps a clock prepared (or enabled) during the whole
lifetime of the driver, these helpers allow to simplify the drivers.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <aardelean@deviqon.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/clk/clk-devres.c | 31 ++++++++++++++
include/linux/clk.h | 90 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 120 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
index fb7761888b30..4707fe718f0b 100644
--- a/drivers/clk/clk-devres.c
+++ b/drivers/clk/clk-devres.c
@@ -67,12 +67,43 @@ struct clk *devm_clk_get(struct device *dev, const char *id)
}
EXPORT_SYMBOL(devm_clk_get);

+struct clk *devm_clk_get_prepared(struct device *dev, const char *id)
+{
+ return __devm_clk_get(dev, id, clk_get, clk_prepare, clk_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_prepared);
+
+struct clk *devm_clk_get_enabled(struct device *dev, const char *id)
+{
+ return __devm_clk_get(dev, id, clk_get,
+ clk_prepare_enable, clk_disable_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_enabled);
+
struct clk *devm_clk_get_optional(struct device *dev, const char *id)
{
return __devm_clk_get(dev, id, clk_get_optional, NULL, NULL);
}
EXPORT_SYMBOL(devm_clk_get_optional);

+struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id)
+{
+ return __devm_clk_get(dev, id, clk_get_optional,
+ clk_prepare, clk_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_optional_prepared);
+
+struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id)
+{
+ return __devm_clk_get(dev, id, clk_get_optional,
+ clk_prepare_enable, clk_disable_unprepare);
+
+}
+EXPORT_SYMBOL(devm_clk_get_optional_enabled);
+
struct clk_bulk_devres {
struct clk_bulk_data *clks;
int num_clks;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 266e8de3cb51..b011dbba7109 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -449,7 +449,7 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
* the clock producer. (IOW, @id may be identical strings, but
* clk_get may return different clock producers depending on @dev.)
*
- * Drivers must assume that the clock source is not enabled.
+ * Drivers must assume that the clock source is neither prepared nor enabled.
*
* devm_clk_get should not be called from within interrupt context.
*
@@ -458,6 +458,47 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
*/
struct clk *devm_clk_get(struct device *dev, const char *id);

+/**
+ * devm_clk_get_prepared - devm_clk_get() + clk_prepare()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Returns a struct clk corresponding to the clock producer, or
+ * valid IS_ERR() condition containing errno. The implementation
+ * uses @dev and @id to determine the clock consumer, and thereby
+ * the clock producer. (IOW, @id may be identical strings, but
+ * clk_get may return different clock producers depending on @dev.)
+ *
+ * The returned clk (if valid) is prepared. Drivers must however assume that the
+ * clock is not enabled.
+ *
+ * devm_clk_get_prepared should not be called from within interrupt context.
+ *
+ * The clock will automatically be unprepared and freed when the
+ * device is unbound from the bus.
+ */
+struct clk *devm_clk_get_prepared(struct device *dev, const char *id);
+
+/**
+ * devm_clk_get_enabled - devm_clk_get() + clk_prepare_enable()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Returns a struct clk corresponding to the clock producer, or valid IS_ERR()
+ * condition containing errno. The implementation uses @dev and @id to
+ * determine the clock consumer, and thereby the clock producer. (IOW, @id may
+ * be identical strings, but clk_get may return different clock producers
+ * depending on @dev.)
+ *
+ * The returned clk (if valid) is prepared and enabled.
+ *
+ * devm_clk_get_prepared should not be called from within interrupt context.
+ *
+ * The clock will automatically be disabled, unprepared and freed when the
+ * device is unbound from the bus.
+ */
+struct clk *devm_clk_get_enabled(struct device *dev, const char *id);
+
/**
* devm_clk_get_optional - lookup and obtain a managed reference to an optional
* clock producer.
@@ -469,6 +510,29 @@ struct clk *devm_clk_get(struct device *dev, const char *id);
*/
struct clk *devm_clk_get_optional(struct device *dev, const char *id);

+/**
+ * devm_clk_get_optional_prepared - devm_clk_get_optional() + clk_prepare()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Behaves the same as devm_clk_get_prepared() except where there is no clock
+ * producer. In this case, instead of returning -ENOENT, the function returns
+ * NULL.
+ */
+struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id);
+
+/**
+ * devm_clk_get_optional_enabled - devm_clk_get_optional() +
+ * clk_prepare_enable()
+ * @dev: device for clock "consumer"
+ * @id: clock consumer ID
+ *
+ * Behaves the same as devm_clk_get_enabled() except where there is no clock
+ * producer. In this case, instead of returning -ENOENT, the function returns
+ * NULL.
+ */
+struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id);
+
/**
* devm_get_clk_from_child - lookup and obtain a managed reference to a
* clock producer from child node.
@@ -813,12 +877,36 @@ static inline struct clk *devm_clk_get(struct device *dev, const char *id)
return NULL;
}

+static inline struct clk *devm_clk_get_prepared(struct device *dev,
+ const char *id)
+{
+ return NULL;
+}
+
+static inline struct clk *devm_clk_get_enabled(struct device *dev,
+ const char *id)
+{
+ return NULL;
+}
+
static inline struct clk *devm_clk_get_optional(struct device *dev,
const char *id)
{
return NULL;
}

+static inline struct clk *devm_clk_get_optional_prepared(struct device *dev,
+ const char *id)
+{
+ return NULL;
+}
+
+static inline struct clk *devm_clk_get_optional_enabled(struct device *dev,
+ const char *id)
+{
+ return NULL;
+}
+
static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
struct clk_bulk_data *clks)
{
--
2.35.1