PM / clock_ops: Add pm_clk_add_clk()

The existing pm_clk_add() allows to pass a clock by con_id. However,
when referring to a specific clock from DT, no con_id is available.

Add pm_clk_add_clk(), which allows to specify the struct clk * directly.
The will will increment refcount on clock pointer, so the caller has
to use clk_put() on clock pointer when done.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 37 insertions, 10 deletions

diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
index 78369305e069..f061eaa48bb5 100644
--- a/drivers/base/power/clock_ops.c
+++ b/drivers/base/power/clock_ops.c
@@ -12,6 +12,7 @@
 #include <linux/pm.h>
 #include <linux/pm_clock.h>
 #include <linux/clk.h>
+#include <linux/clkdev.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 
@@ -53,7 +54,8 @@ static inline int __pm_clk_enable(struct device *dev, struct clk *clk)
  */
 static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
 {
-        ce->clk = clk_get(dev, ce->con_id);
+        if (!ce->clk)
+                ce->clk = clk_get(dev, ce->con_id);
         if (IS_ERR(ce->clk)) {
                 ce->status = PCE_STATUS_ERROR;
         } else {
@@ -63,15 +65,8 @@ static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
         }
 }
 
-/**
- * pm_clk_add - Start using a device clock for power management.
- * @dev: Device whose clock is going to be used for power management.
- * @con_id: Connection ID of the clock.
- *
- * Add the clock represented by @con_id to the list of clocks used for
- * the power management of @dev.
- */
-int pm_clk_add(struct device *dev, const char *con_id)
+static int __pm_clk_add(struct device *dev, const char *con_id,
+                        struct clk *clk)
 {
         struct pm_subsys_data *psd = dev_to_psd(dev);
         struct pm_clock_entry *ce;
@@ -93,6 +88,12 @@ int pm_clk_add(struct device *dev, const char *con_id)
                         kfree(ce);
                         return -ENOMEM;
                 }
+        } else {
+                if (IS_ERR(ce->clk) || !__clk_get(clk)) {
+                        kfree(ce);
+                        return -ENOENT;
+                }
+                ce->clk = clk;
         }
 
         pm_clk_acquire(dev, ce);
@@ -104,6 +105,32 @@ int pm_clk_add(struct device *dev, const char *con_id)
 }
 
 /**
+ * pm_clk_add - Start using a device clock for power management.
+ * @dev: Device whose clock is going to be used for power management.
+ * @con_id: Connection ID of the clock.
+ *
+ * Add the clock represented by @con_id to the list of clocks used for
+ * the power management of @dev.
+ */
+int pm_clk_add(struct device *dev, const char *con_id)
+{
+        return __pm_clk_add(dev, con_id, NULL);
+}
+
+/**
+ * pm_clk_add_clk - Start using a device clock for power management.
+ * @dev: Device whose clock is going to be used for power management.
+ * @clk: Clock pointer
+ *
+ * Add the clock to the list of clocks used for the power management of @dev.
+ * It will increment refcount on clock pointer, use clk_put() on it when done.
+ */
+int pm_clk_add_clk(struct device *dev, struct clk *clk)
+{
+        return __pm_clk_add(dev, NULL, clk);
+}
+
+/**
  * __pm_clk_remove - Destroy PM clock entry.
  * @ce: PM clock entry to destroy.
  */