[PATCH RFC v3 1/2] clk: Add function parsing arbitrary clock list DT property

Sylwester Nawrocki
2014-03-27T12:16:18Z

The of_clk_get_by_property() function added by this patch is similar to
of_clk_get(), except it allows to pass name of a DT property containing
list of phandles and clock specifiers. For of_clk_get() this has been
hard coded to "clocks".

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
Changes since v2:
- moved the function declaration from drivers/clk/clk.h to
include/linux/clk.h

Changes since v1:
- s/of_clk_get_list_entry/of_clk_get_by_property.
---
drivers/clk/clkdev.c | 25 +++++++++++++++++++++----
include/linux/clk.h | 7 +++++++
2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index a360b2e..1d41540 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -27,17 +27,28 @@ static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);

#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
-struct clk *of_clk_get(struct device_node *np, int index)
+/**
+ * of_clk_get_by_property() - Parse and lookup a clock referenced by a device node
+ * @np: pointer to clock consumer node
+ * @list_name: name of the clock list property
+ * @index: index to the clock list
+ *
+ * This function parses the @list_name property and together with @index
+ * value indicating an entry of the list uses it to look up the struct clk
+ * from the registered list of clock providers.
+ */
+struct clk *of_clk_get_by_property(struct device_node *np,
+ const char *list_name, int index)
{
struct of_phandle_args clkspec;
struct clk *clk;
int rc;

- if (index < 0)
+ if (index < 0 || !list_name)
return ERR_PTR(-EINVAL);

- rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
- &clkspec);
+ rc = of_parse_phandle_with_args(np, list_name, "#clock-cells",
+ index, &clkspec);
if (rc)
return ERR_PTR(rc);

@@ -51,6 +62,12 @@ struct clk *of_clk_get(struct device_node *np, int index)
of_node_put(clkspec.np);
return clk;
}
+EXPORT_SYMBOL(of_clk_get_by_property);
+
+struct clk *of_clk_get(struct device_node *np, int index)
+{
+ return of_clk_get_by_property(np, "clocks", index);
+}
EXPORT_SYMBOL(of_clk_get);

/**
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 0dd9114..f71235b 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -383,6 +383,8 @@ struct of_phandle_args;

#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
struct clk *of_clk_get(struct device_node *np, int index);
+struct clk *of_clk_get_by_property(struct device_node *np,
+ const char *list_name, int index);
struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
#else
@@ -395,6 +397,11 @@ static inline struct clk *of_clk_get_by_name(struct device_node *np,
{
return ERR_PTR(-ENOENT);
}
+struct clk *of_clk_get_by_property(struct device_node *np,
+ const char *list_name, int index)
+{
+ return ERR_PTR(-ENOENT);
+}
#endif

#endif
--
1.7.9.5