clk: add clk_core_set_phase_nolock function

Create a core function for set_phase, as it is done for set_rate and
set_parent.

This rework is done to ease the integration of "protected" clock
functionality.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171201215200.23523-4-jbrunet@baylibre.com

drivers/clk/clk.c

@@ -1966,6 +1966,25 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
 }
 EXPORT_SYMBOL_GPL(clk_set_parent);
 
+static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
+{
+	int ret = -EINVAL;
+
+	lockdep_assert_held(&prepare_lock);
+
+	if (!core)
+		return 0;
+
+	trace_clk_set_phase(core, degrees);
+
+	if (core->ops->set_phase)
+		ret = core->ops->set_phase(core->hw, degrees);
+
+	trace_clk_set_phase_complete(core, degrees);
+
+	return ret;
+}
+
 /**
  * clk_set_phase - adjust the phase shift of a clock signal
  * @clk: clock signal source
@@ -1988,7 +2007,7 @@ EXPORT_SYMBOL_GPL(clk_set_parent);
  */
 int clk_set_phase(struct clk *clk, int degrees)
 {
-	int ret = -EINVAL;
+	int ret;
 
 	if (!clk)
 		return 0;
@@ -1999,17 +2018,7 @@ int clk_set_phase(struct clk *clk, int degrees)
 		degrees += 360;
 
 	clk_prepare_lock();
-
-	trace_clk_set_phase(clk->core, degrees);
-
-	if (clk->core->ops->set_phase)
-		ret = clk->core->ops->set_phase(clk->core->hw, degrees);
-
-	trace_clk_set_phase_complete(clk->core, degrees);
-
-	if (!ret)
-		clk->core->phase = degrees;
-
+	ret = clk_core_set_phase_nolock(clk->core, degrees);
 	clk_prepare_unlock();
 
 	return ret;