[PATCH v7 3/9] clk: fixed-factor: Rework initialization with parent clocks

[Benoît Monin]

Use the same sequence as clk-divider, clk-gate and other to set the
parent_names, parent_hws and parent_data in the init struct when
registering a fixed-factor clock. The number of parent clocks is now
only set to one if a parent clock is provided.

Previously the number of parent clocks was always one, forcing callers
of __clk_hw_register_fixed_factor() to provide a dummy parent_data
struct with an invalid clock index in case they were not provided with
a non-NULL parent_name or parent_hw. Drop this dummy parent_data as is
not necessary anymore.

This change only has a small impact on mis-configured fixed-factor. Now a
call to clk_hw_register_fixed_factor() with a NULL parent will register
a fixed-factor with zero parent while previously it was registered with
one invalid parent. In both cases the rate of the fixed-factor is 0Hz
but it is no longer shown as orphaned.

This has no impact on properly configured fixed-factors clocks which
have a valid parent set.

In clk_factor_determine_rate(), make sure the parent clock is valid
before accessing it because the mis-configured fixed-factor now have a
NULL parent.

Signed-off-by: Benoît Monin <benoit.monin@xxxxxxxxxxx>
---
 drivers/clk/clk-fixed-factor.c | 34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)

diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index 850e8b95f352..60e32482d347 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -36,10 +36,14 @@ static int clk_factor_determine_rate(struct clk_hw *hw,
 	struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
 
 	if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
+		struct clk_hw *parent_hw = clk_hw_get_parent(hw);
 		unsigned long best_parent;
 
+		if (!parent_hw)
+			return -EINVAL;
+
 		best_parent = (req->rate / fix->mult) * fix->div;
-		req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
+		req->best_parent_rate = clk_hw_round_rate(parent_hw, best_parent);
 	}
 
 	req->rate = (req->best_parent_rate / fix->div) * fix->mult;
@@ -124,13 +128,13 @@ __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
 	init.name = name;
 	init.ops = &clk_fixed_factor_ops;
 	init.flags = flags;
-	if (parent_name)
-		init.parent_names = &parent_name;
-	else if (parent_hw)
-		init.parent_hws = &parent_hw;
+	init.parent_names = parent_name ? &parent_name : NULL;
+	init.parent_hws = parent_hw ? &parent_hw : NULL;
+	init.parent_data = pdata;
+	if (parent_name || parent_hw || pdata)
+		init.num_parents = 1;
 	else
-		init.parent_data = pdata;
-	init.num_parents = 1;
+		init.num_parents = 0;
 
 	hw = &fix->hw;
 	if (dev)
@@ -190,10 +194,8 @@ struct clk_hw *devm_clk_hw_register_fixed_factor_parent_hw(struct device *dev,
 		const char *name, const struct clk_hw *parent_hw,
 		unsigned long flags, unsigned int mult, unsigned int div)
 {
-	const struct clk_parent_data pdata = { .index = -1 };
-
 	return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
-					      &pdata, flags, mult, div, 0, 0, true);
+					      NULL, flags, mult, div, 0, 0, true);
 }
 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_parent_hw);
 
@@ -201,10 +203,8 @@ struct clk_hw *clk_hw_register_fixed_factor_parent_hw(struct device *dev,
 		const char *name, const struct clk_hw *parent_hw,
 		unsigned long flags, unsigned int mult, unsigned int div)
 {
-	const struct clk_parent_data pdata = { .index = -1 };
-
 	return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
-					      &pdata, flags, mult, div, 0, 0, false);
+					      NULL, flags, mult, div, 0, 0, false);
 }
 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_parent_hw);
 
@@ -212,10 +212,8 @@ struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
 		const char *name, const char *parent_name, unsigned long flags,
 		unsigned int mult, unsigned int div)
 {
-	const struct clk_parent_data pdata = { .index = -1 };
-
 	return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL,
-					      &pdata, flags, mult, div, 0, 0, false);
+					      NULL, flags, mult, div, 0, 0, false);
 }
 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
 
@@ -296,10 +294,8 @@ struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
 		const char *name, const char *parent_name, unsigned long flags,
 		unsigned int mult, unsigned int div)
 {
-	const struct clk_parent_data pdata = { .index = -1 };
-
 	return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL,
-			&pdata, flags, mult, div, 0, 0, true);
+			NULL, flags, mult, div, 0, 0, true);
 }
 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
 

-- 
2.54.0