[PATCH v2 0/2] clk: ti: mux: resolve parent clocks by DT index, not by name

[PATCH v2 0/2] clk: ti: mux: resolve parent clocks by DT index, not by name

[Mathieu Dubois-Briand]

This commit aims to solve an issue I've been describing a few months ago
on AM335x SoC [1]. I believe using the parent_data field of
clk_init_data structure is now the preferred way to convey that data,
and it should be more reliable than string comparisons.

[1]: https://lore.kernel.org/all/DI4RUFQNSSNP.2QMSSQWJW9I2O@bootlin.com/

Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
---
Changes in v2:
- Also use clk_parent_data structure in composite.c.
- Rebase on v7.2-rc5.
- Link to v1: https://lore.kernel.org/r/20260715-mathieu-wdt-clock-theo-v1-1-da65bba1828b@bootlin.com

---
Mathieu Dubois-Briand (2):
      clk: ti: mux: resolve parent clocks by DT index, not by name
      clk: ti: composite: resolve parent clocks by DT index, not by name

 drivers/clk/ti/composite.c | 26 ++++++++++++++------------
 drivers/clk/ti/mux.c       | 20 +++++++++++---------
 2 files changed, 25 insertions(+), 21 deletions(-)
---
base-commit: f5098b6bae761e346ebcd9da7f95622c04733cff
change-id: 20260713-mathieu-wdt-clock-theo-f0c5ba58e258

Best regards,
-- 
Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>

[PATCH v2 1/2] clk: ti: mux: resolve parent clocks by DT index, not by name

[Mathieu Dubois-Briand]

Resolve parent clocks by their index into the device tree "clocks"
property rather than matching names as strings. Name-based matching is
fragile because a clock's "clock-output-names" value in its provider
node can differ from the name used to reference it in a consumer node,
and because names must be globally unique across all clock providers.

On AM335x, this caused broken clock trees where some clocks failed to
enable because their parents could not be found.

Replace of_clk_parent_fill() with a clk_parent_data array that sets
.index to the array position.

Fixes: ec7aa25fa483 ("ARM: dts: Use clock-output-names for am3")
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
---
 drivers/clk/ti/mux.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c
index d6a0ccfd81db..ded4432f7528 100644
--- a/drivers/clk/ti/mux.c
+++ b/drivers/clk/ti/mux.c
@@ -119,7 +119,7 @@ const struct clk_ops ti_clk_mux_ops = {
 };
 
 static struct clk *_register_mux(struct device_node *node, const char *name,
-				 const char * const *parent_names,
+				 const struct clk_parent_data *parent_data,
 				 u8 num_parents, unsigned long flags,
 				 struct clk_omap_reg *reg, u8 shift, u32 mask,
 				 s8 latch, u8 clk_mux_flags, u32 *table)
@@ -136,7 +136,7 @@ static struct clk *_register_mux(struct device_node *node, const char *name,
 	init.name = name;
 	init.ops = &ti_clk_mux_ops;
 	init.flags = flags;
-	init.parent_names = parent_names;
+	init.parent_data = parent_data;
 	init.num_parents = num_parents;
 
 	/* struct clk_mux assignments */
@@ -167,24 +167,26 @@ static void of_mux_clk_setup(struct device_node *node)
 	struct clk *clk;
 	struct clk_omap_reg reg;
 	unsigned int num_parents;
-	const char **parent_names;
+	struct clk_parent_data *parent_data;
 	const char *name;
 	u8 clk_mux_flags = 0;
 	u32 mask = 0;
 	u32 shift = 0;
 	s32 latch = -EINVAL;
 	u32 flags = CLK_SET_RATE_NO_REPARENT;
+	int i;
 
 	num_parents = of_clk_get_parent_count(node);
 	if (num_parents < 2) {
 		pr_err("mux-clock %pOFn must have parents\n", node);
 		return;
 	}
-	parent_names = kcalloc(num_parents, sizeof(char *), GFP_KERNEL);
-	if (!parent_names)
-		goto cleanup;
+	parent_data = kcalloc(num_parents, sizeof(*parent_data), GFP_KERNEL);
+	if (!parent_data)
+		return;
 
-	of_clk_parent_fill(node, parent_names, num_parents);
+	for (i = 0; i < num_parents; i++)
+		parent_data[i].index = i;
 
 	if (ti_clk_get_reg_addr(node, 0, &reg))
 		goto cleanup;
@@ -207,7 +209,7 @@ static void of_mux_clk_setup(struct device_node *node)
 	mask = (1 << fls(mask)) - 1;
 
 	name = ti_dt_clk_name(node);
-	clk = _register_mux(node, name, parent_names, num_parents,
+	clk = _register_mux(node, name, parent_data, num_parents,
 			    flags, &reg, shift, mask, latch, clk_mux_flags,
 			    NULL);
 
@@ -215,7 +217,7 @@ static void of_mux_clk_setup(struct device_node *node)
 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
 
 cleanup:
-	kfree(parent_names);
+	kfree(parent_data);
 }
 CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup);
 

-- 
2.47.3

[PATCH v2 2/2] clk: ti: composite: resolve parent clocks by DT index, not by name

[Mathieu Dubois-Briand]

Resolve parent clocks by their index into the device tree "clocks"
property rather than matching names as strings. This makes it consistent
with other parts of the same driver.

Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
---
 drivers/clk/ti/composite.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/clk/ti/composite.c b/drivers/clk/ti/composite.c
index c379bbdae25a..01eae8995254 100644
--- a/drivers/clk/ti/composite.c
+++ b/drivers/clk/ti/composite.c
@@ -52,7 +52,7 @@ static const struct clk_ops ti_composite_gate_ops = {
 
 struct component_clk {
 	int num_parents;
-	const char **parent_names;
+	struct clk_parent_data *parent_data;
 	struct device_node *node;
 	int type;
 	struct clk_hw *hw;
@@ -116,7 +116,7 @@ static void __init _register_composite(void *user,
 	struct clk_hw_omap_comp *cclk = to_clk_hw_comp(hw);
 	struct component_clk *comp;
 	int num_parents = 0;
-	const char **parent_names = NULL;
+	struct clk_parent_data *parent_data = NULL;
 	const char *name;
 	int i;
 	int ret;
@@ -155,7 +155,7 @@ static void __init _register_composite(void *user,
 			continue;
 		if (comp->num_parents) {
 			num_parents = comp->num_parents;
-			parent_names = comp->parent_names;
+			parent_data = comp->parent_data;
 			break;
 		}
 	}
@@ -166,8 +166,8 @@ static void __init _register_composite(void *user,
 	}
 
 	name = ti_dt_clk_name(node);
-	clk = clk_register_composite(NULL, name,
-				     parent_names, num_parents,
+	clk = clk_register_composite_pdata(NULL, name,
+				     parent_data, num_parents,
 				     _get_hw(cclk, CLK_COMPONENT_TYPE_MUX),
 				     &ti_clk_mux_ops,
 				     _get_hw(cclk, CLK_COMPONENT_TYPE_DIVIDER),
@@ -190,7 +190,7 @@ static void __init _register_composite(void *user,
 		if (!cclk->comp_clks[i])
 			continue;
 		list_del(&cclk->comp_clks[i]->link);
-		kfree(cclk->comp_clks[i]->parent_names);
+		kfree(cclk->comp_clks[i]->parent_data);
 		kfree(cclk->comp_clks[i]);
 	}
 
@@ -237,8 +237,9 @@ int __init ti_clk_add_component(struct device_node *node, struct clk_hw *hw,
 				int type)
 {
 	unsigned int num_parents;
-	const char **parent_names;
+	struct clk_parent_data *parent_data;
 	struct component_clk *clk;
+	unsigned int i;
 
 	num_parents = of_clk_get_parent_count(node);
 
@@ -247,20 +248,21 @@ int __init ti_clk_add_component(struct device_node *node, struct clk_hw *hw,
 		return -EINVAL;
 	}
 
-	parent_names = kcalloc(num_parents, sizeof(char *), GFP_KERNEL);
-	if (!parent_names)
+	parent_data = kcalloc(num_parents, sizeof(*parent_data), GFP_KERNEL);
+	if (!parent_data)
 		return -ENOMEM;
 
-	of_clk_parent_fill(node, parent_names, num_parents);
+	for (i = 0; i < num_parents; i++)
+		parent_data[i].index = i;
 
 	clk = kzalloc_obj(*clk);
 	if (!clk) {
-		kfree(parent_names);
+		kfree(parent_data);
 		return -ENOMEM;
 	}
 
 	clk->num_parents = num_parents;
-	clk->parent_names = parent_names;
+	clk->parent_data = parent_data;
 	clk->hw = hw;
 	clk->node = node;
 	clk->type = type;

-- 
2.47.3

Re: [PATCH v2 1/2] clk: ti: mux: resolve parent clocks by DT index, not by name

[Brian Masney]

On Mon, Jul 27, 2026 at 09:41:40AM +0200, Mathieu Dubois-Briand wrote:
> Resolve parent clocks by their index into the device tree "clocks"
> property rather than matching names as strings. Name-based matching is
> fragile because a clock's "clock-output-names" value in its provider
> node can differ from the name used to reference it in a consumer node,
> and because names must be globally unique across all clock providers.
> 
> On AM335x, this caused broken clock trees where some clocks failed to
> enable because their parents could not be found.
> 
> Replace of_clk_parent_fill() with a clk_parent_data array that sets
> .index to the array position.
> 
> Fixes: ec7aa25fa483 ("ARM: dts: Use clock-output-names for am3")
> Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>

Reviewed-by: Brian Masney <bmasney@redhat.com>

Re: [PATCH v2 2/2] clk: ti: composite: resolve parent clocks by DT index, not by name

[Brian Masney]

On Mon, Jul 27, 2026 at 09:41:41AM +0200, Mathieu Dubois-Briand wrote:
> Resolve parent clocks by their index into the device tree "clocks"
> property rather than matching names as strings. This makes it consistent
> with other parts of the same driver.
> 
> Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>

Reviewed-by: Brian Masney <bmasney@redhat.com>