2 files changed, 15 insertions, 0 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index d87661af0c72..113d75db371d 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1934,6 +1934,16 @@ int __clk_init(struct device *dev, struct clk *clk)
                 clk->accuracy = 0;
 
         /*
+         * Set clk's phase.
+         * Since a phase is by definition relative to its parent, just
+         * query the current clock phase, or just assume it's in phase.
+         */
+        if (clk->ops->get_phase)
+                clk->phase = clk->ops->get_phase(clk->hw);
+        else
+                clk->phase = 0;
+
+        /*
          * Set clk's rate.  The preferred method is to use .recalc_rate.  For
          * simple clocks and lazy developers the default fallback is to use the
          * parent's rate.  If a clock doesn't have a parent (or is orphaned)
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 69b20d4c1e1a..abec961092a7 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -130,6 +130,10 @@ struct dentry;
  *              set then clock accuracy will be initialized to parent accuracy
  *              or 0 (perfect clock) if clock has no parent.
  *
+ * @get_phase:  Queries the hardware to get the current phase of a clock.
+ *              Returned values are 0-359 degrees on success, negative
+ *              error codes on failure.
+ *
  * @set_phase:  Shift the phase this clock signal in degrees specified
  *              by the second argument. Valid values for degrees are
  *              0-359. Return 0 on success, otherwise -EERROR.
@@ -182,6 +186,7 @@ struct clk_ops {
                                     unsigned long parent_rate, u8 index);
         unsigned long   (*recalc_accuracy)(struct clk_hw *hw,
                                            unsigned long parent_accuracy);
+        int             (*get_phase)(struct clk_hw *hw);
         int             (*set_phase)(struct clk_hw *hw, int degrees);
         void            (*init)(struct clk_hw *hw);
         int             (*debug_init)(struct clk_hw *hw, struct dentry *dentry);