PM / clk: Add support for obtaining clocks from device-tree

The PM clocks framework requires clients to pass either a con-id or a
valid clk pointer in order to add a clock to a device. Add a new
function of_pm_clk_add_clks() to allows device clocks to be retrieved
from device-tree and populated for a given device. Note that it is
not necessary to make the compilation of this new function dependent
upon CONFIG_OF because there are stubs functions for the device-tree
APIs used.

In order to handle errors encountered when adding clocks from
device-tree, add a function pm_clk_remove_clk() to remove any clocks
(using a pointer to the clk structure) that have been added
successfully before the error occurred.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/pm_clock.h b/include/linux/pm_clock.h
index 25266c600021..308d6044f153 100644
--- a/include/linux/pm_clock.h
+++ b/include/linux/pm_clock.h
@@ -42,7 +42,9 @@ extern int pm_clk_create(struct device *dev);
 extern void pm_clk_destroy(struct device *dev);
 extern int pm_clk_add(struct device *dev, const char *con_id);
 extern int pm_clk_add_clk(struct device *dev, struct clk *clk);
+extern int of_pm_clk_add_clks(struct device *dev);
 extern void pm_clk_remove(struct device *dev, const char *con_id);
+extern void pm_clk_remove_clk(struct device *dev, struct clk *clk);
 extern int pm_clk_suspend(struct device *dev);
 extern int pm_clk_resume(struct device *dev);
 #else
@@ -69,11 +71,18 @@ static inline int pm_clk_add_clk(struct device *dev, struct clk *clk)
 {
         return -EINVAL;
 }
+static inline int of_pm_clk_add_clks(struct device *dev)
+{
+        return -EINVAL;
+}
 static inline void pm_clk_remove(struct device *dev, const char *con_id)
 {
 }
 #define pm_clk_suspend  NULL
 #define pm_clk_resume   NULL
+static inline void pm_clk_remove_clk(struct device *dev, struct clk *clk)
+{
+}
 #endif
 
 #ifdef CONFIG_HAVE_CLK