Re: [PATCH v2 2/3] clk: add api to get clk consumer from clk_hw

2020-11-14 Thread Stephen Boyd
Quoting Jerome Brunet (2020-10-21 09:21:46)
> clk_register() is deprecated. Using 'clk' member of struct clk_hw is
> discouraged. With this constraint, it is difficult for driver to
> register clocks using the clk_hw API and then use the clock with
> the consumer API
> 
> This adds a simple helper, clk_hw_get_clk(), to get a struct clk from
> a struct clk_hw. Like other clk_get() variant, each call to this helper
> must be balanced with a call to clk_put(). To make life easier on the
> consumers, a memory managed version is provided as well.
> 
> Cc: Martin Blumenstingl 
> Signed-off-by: Jerome Brunet 
> ---

Applied to clk-next


[PATCH v2 2/3] clk: add api to get clk consumer from clk_hw

2020-10-21 Thread Jerome Brunet
clk_register() is deprecated. Using 'clk' member of struct clk_hw is
discouraged. With this constraint, it is difficult for driver to
register clocks using the clk_hw API and then use the clock with
the consumer API

This adds a simple helper, clk_hw_get_clk(), to get a struct clk from
a struct clk_hw. Like other clk_get() variant, each call to this helper
must be balanced with a call to clk_put(). To make life easier on the
consumers, a memory managed version is provided as well.

Cc: Martin Blumenstingl 
Signed-off-by: Jerome Brunet 
---
 drivers/clk/clk.c| 61 
 include/linux/clk-provider.h |  5 +++
 2 files changed, 66 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 88e5797bb6b4..d27153f26fa9 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3667,6 +3667,24 @@ struct clk *clk_hw_create_clk(struct device *dev, struct 
clk_hw *hw,
return clk;
 }
 
+/**
+ * clk_hw_get_clk: get clk consumer given an clk_hw
+ * @hw: clk_hw associated with the clk being consumed
+ * @con_id: connection ID string on device
+ *
+ * Returns: new clk consumer
+ * This is the function to be used by providers which need
+ * to get a consumer clk and act on the clock element
+ * Calls to this function must be balanced with calls clk_put()
+ */
+struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
+{
+   struct device *dev = hw->core->dev;
+
+   return clk_hw_create_clk(dev, hw, dev_name(dev), con_id);
+}
+EXPORT_SYMBOL(clk_hw_get_clk);
+
 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
 {
const char *dst;
@@ -4187,6 +4205,49 @@ void devm_clk_hw_unregister(struct device *dev, struct 
clk_hw *hw)
 }
 EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
 
+static void devm_clk_release(struct device *dev, void *res)
+{
+   clk_put(*(struct clk **)res);
+}
+
+/**
+ * devm_clk_hw_get_clk: resource managed clk_hw_get_clk()
+ * @dev: device that is registering this clock
+ * @hw: clk_hw associated with the clk being consumed
+ * @con_id: connection ID string on device
+ *
+ * Managed clk_hw_get_clk(). Clocks got with this function are
+ * automatically clk_put() on driver detach. See clk_put()
+ * for more information.
+ */
+struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
+   const char *con_id)
+{
+   struct clk *clk;
+   struct clk **clkp;
+
+   /* This should not happen because it would mean we have drivers
+* passing around clk_hw pointers instead of having the caller use
+* proper clk_get() style APIs
+*/
+   WARN_ON_ONCE(dev != hw->core->dev);
+
+   clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
+   if (!clkp)
+   return ERR_PTR(-ENOMEM);
+
+   clk = clk_hw_get_clk(hw, con_id);
+   if (!IS_ERR(clk)) {
+   *clkp = clk;
+   devres_add(dev, clkp);
+   } else {
+   devres_free(clkp);
+   }
+
+   return clk;
+}
+EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
+
 /*
  * clkdev helpers
  */
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 03a5de5f99f4..86b707520ec0 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -1088,6 +1088,11 @@ static inline struct clk_hw *__clk_get_hw(struct clk 
*clk)
return (struct clk_hw *)clk;
 }
 #endif
+
+struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id);
+struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
+   const char *con_id);
+
 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw);
 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw);
 struct clk_hw *clk_hw_get_parent_by_index(const struct clk_hw *hw,
-- 
2.25.4