[RFC 3/7] clk: rework calls to round and determine rate callbacks

[Jerome Brunet]

Rework the way the callbacks round_rate and determine_rate are called. The
goal is to do this at a single point and make it easier to add conditions
before calling them.

This rework is done to ease the integration of "protected" clock
functionality.

Signed-off-by: Jerome Brunet <jbrunet at baylibre.com>
---
 drivers/clk/clk.c | 78 +++++++++++++++++++++++++++++++------------------------
 1 file changed, 44 insertions(+), 34 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 57982a06dbce..fa77a1841e0f 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -833,16 +833,34 @@ static int clk_disable_unused(void)
 }
 late_initcall_sync(clk_disable_unused);
 
-static int clk_core_round_rate_nolock(struct clk_core *core,
-				      struct clk_rate_request *req)
+static int clk_core_determine_round(struct clk_core *core,
+				    struct clk_rate_request *req)
 {
-	struct clk_core *parent;
 	long rate;
 
-	lockdep_assert_held(&prepare_lock);
+	if (core->ops->determine_rate) {
+		return core->ops->determine_rate(core->hw, req);
+	} else if (core->ops->round_rate) {
+		rate = core->ops->round_rate(core->hw, req->rate,
+					     &req->best_parent_rate);
+		if (rate < 0)
+			return rate;
 
-	if (!core)
-		return 0;
+		req->rate = rate;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void clk_core_init_rate_req(struct clk_core *core,
+				   struct clk_rate_request *req)
+{
+	struct clk_core *parent;
+
+	if (WARN_ON(!core || !req))
+		return;
 
 	parent = core->parent;
 	if (parent) {
@@ -852,22 +870,24 @@ static int clk_core_round_rate_nolock(struct clk_core *core,
 		req->best_parent_hw = NULL;
 		req->best_parent_rate = 0;
 	}
+}
 
-	if (core->ops->determine_rate) {
-		return core->ops->determine_rate(core->hw, req);
-	} else if (core->ops->round_rate) {
-		rate = core->ops->round_rate(core->hw, req->rate,
-					     &req->best_parent_rate);
-		if (rate < 0)
-			return rate;
+static int clk_core_round_rate_nolock(struct clk_core *core,
+				      struct clk_rate_request *req)
+{
+	lockdep_assert_held(&prepare_lock);
 
-		req->rate = rate;
-	} else if (core->flags & CLK_SET_RATE_PARENT) {
-		return clk_core_round_rate_nolock(parent, req);
-	} else {
-		req->rate = core->rate;
-	}
+	if (!core)
+		return 0;
+
+	clk_core_init_rate_req(core, req);
+
+	if (core->ops->determine_rate || core->ops->round_rate)
+		return clk_core_determine_round(core, req);
+	else if (core->flags & CLK_SET_RATE_PARENT)
+		return clk_core_round_rate_nolock(core->parent, req);
 
+	req->rate = core->rate;
 	return 0;
 }
 
@@ -1354,36 +1374,26 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core,
 	clk_core_get_boundaries(core, &min_rate, &max_rate);
 
 	/* find the closest rate and parent clk/rate */
-	if (core->ops->determine_rate) {
+	if (core->ops->determine_rate || core->ops->round_rate) {
 		struct clk_rate_request req;
 
 		req.rate = rate;
 		req.min_rate = min_rate;
 		req.max_rate = max_rate;
-		if (parent) {
-			req.best_parent_hw = parent->hw;
-			req.best_parent_rate = parent->rate;
-		} else {
-			req.best_parent_hw = NULL;
-			req.best_parent_rate = 0;
-		}
 
-		ret = core->ops->determine_rate(core->hw, &req);
+		clk_core_init_rate_req(core, req);
+
+		ret = clk_core_determine_round(core, &req);
 		if (ret < 0)
 			return NULL;
 
 		best_parent_rate = req.best_parent_rate;
 		new_rate = req.rate;
 		parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
-	} else if (core->ops->round_rate) {
-		ret = core->ops->round_rate(core->hw, rate,
-					    &best_parent_rate);
-		if (ret < 0)
-			return NULL;
 
-		new_rate = ret;
 		if (new_rate < min_rate || new_rate > max_rate)
 			return NULL;
+
 	} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
 		/* pass-through clock without adjustable parent */
 		core->new_rate = core->rate;
-- 
2.9.3