[PATCH v3] media: v4l2-common: Always register clock with device-specific name

[PATCH v3] media: v4l2-common: Always register clock with device-specific name

[Paul Cercueil]

If we need to register a dummy fixed-frequency clock, always register it
using a device-specific name.

This supports the use case where a system has two of the same sensor,
meaning two instances of the same driver, which previously both tried
(and failed) to create a clock with the same name.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---

Notes:
    v2: include requested clock id in fixed clock name
    
    v3: support NULL clock id

 drivers/media/v4l2-core/v4l2-common.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 554c591e1113..0f9c78cfc6ed 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -792,14 +792,15 @@ struct clk *__devm_v4l2_sensor_clk_get(struct device *dev, const char *id,
 	if (ret)
 		return ERR_PTR(ret == -EINVAL ? -EPROBE_DEFER : ret);
 
-	if (!id) {
+	if (id)
+		clk_id = kasprintf(GFP_KERNEL, "clk-%s-%s", dev_name(dev), id);
+	else
 		clk_id = kasprintf(GFP_KERNEL, "clk-%s", dev_name(dev));
-		if (!clk_id)
-			return ERR_PTR(-ENOMEM);
-		id = clk_id;
-	}
 
-	clk_hw = devm_clk_hw_register_fixed_rate(dev, id, NULL, 0, rate);
+	if (!clk_id)
+		return ERR_PTR(-ENOMEM);
+
+	clk_hw = devm_clk_hw_register_fixed_rate(dev, clk_id, NULL, 0, rate);
 	if (IS_ERR(clk_hw))
 		return ERR_CAST(clk_hw);
 
-- 
2.53.0

Re: [PATCH v3] media: v4l2-common: Always register clock with device-specific name

[Mehdi Djait]

Hi Paul,

Thank you for the patch!

On Tue, Mar 31, 2026 at 10:43:40AM +0200, Paul Cercueil wrote:
> If we need to register a dummy fixed-frequency clock, always register it
> using a device-specific name.
> 
> This supports the use case where a system has two of the same sensor,
> meaning two instances of the same driver, which previously both tried
> (and failed) to create a clock with the same name.
> 

Reviewed-by: Mehdi Djait <mehdi.djait@linux.intel.com>

> Signed-off-by: Paul Cercueil <paul@crapouillou.net>

--
Kind Regards
Mehdi Djait