linux-kernel - [PATCH v2 03/10] clk: fixed-factor: Rework initialization with parent clocks

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Message-Id: <20251224-clk-eyeq7-v2-3-81744d1025d9@bootlin.com>
Date: Wed, 24 Dec 2025 11:07:16 +0100
From: Benoît Monin <benoit.monin@...tlin.com>
To: Vladimir Kondratiev <vladimir.kondratiev@...ileye.com>, 
 Gregory CLEMENT <gregory.clement@...tlin.com>, 
 Théo Lebrun <theo.lebrun@...tlin.com>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, 
 Michael Turquette <mturquette@...libre.com>, 
 Stephen Boyd <sboyd@...nel.org>, Philipp Zabel <p.zabel@...gutronix.de>, 
 Paul Walmsley <pjw@...nel.org>, Palmer Dabbelt <palmer@...belt.com>, 
 Albert Ou <aou@...s.berkeley.edu>, Alexandre Ghiti <alex@...ti.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 Tawfik Bayouk <tawfik.bayouk@...ileye.com>, linux-riscv@...ts.infradead.org, 
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-clk@...r.kernel.org, linux-mips@...r.kernel.org, 
 Benoît Monin <benoit.monin@...tlin.com>
Subject: [PATCH v2 03/10] clk: fixed-factor: Rework initialization with
 parent clocks

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.

Signed-off-by: Benoît Monin <benoit.monin@...tlin.com>
---
 drivers/clk/clk-fixed-factor.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index de658c9e4c53..63082115fd25 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -124,13 +124,13 @@ __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 +190,8 @@ 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 +199,8 @@ 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 +208,8 @@ 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 +290,8 @@ 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);
 

-- 
2.52.0