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[PATCH RFC 2/8] media: qcom: camss: csiphy: Introduce C-PHY

David Heidelberg via B4 Relay posted 8 patches 3 months ago
There is a newer version of this series
[PATCH RFC 2/8] media: qcom: camss: csiphy: Introduce C-PHY
Posted by David Heidelberg via B4 Relay 3 months ago 
From: David Heidelberg <david@ixit.cz>

Read C-PHY from the device-tree bus-type and save it into the csiphy
structure for later use.

For C-PHY, skip clock line configuration, as there is none.

Signed-off-by: David Heidelberg <david@ixit.cz>
---
 drivers/media/platform/qcom/camss/camss-csiphy.h | 2 ++
 drivers/media/platform/qcom/camss/camss.c        | 8 ++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/drivers/media/platform/qcom/camss/camss-csiphy.h
index 895f80003c441..8f7d0e4c73075 100644
--- a/drivers/media/platform/qcom/camss/camss-csiphy.h
+++ b/drivers/media/platform/qcom/camss/camss-csiphy.h
@@ -28,11 +28,13 @@ struct csiphy_lane {
 
 /**
  * struct csiphy_lanes_cfg - CSIPHY lanes configuration
+ * @cphy:     true if C-PHY is used, false if D-PHY is used
  * @num_data: number of data lanes
  * @data:     data lanes configuration
  * @clk:      clock lane configuration (only for D-PHY)
  */
 struct csiphy_lanes_cfg {
+	bool cphy;
 	int num_data;
 	struct csiphy_lane *data;
 	struct csiphy_lane clk;
diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index fcc2b2c3cba07..549780f3f948b 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -4055,9 +4055,13 @@ static int camss_of_parse_endpoint_node(struct device *dev,
 	csd->interface.csiphy_id = vep.base.port;
 
 	mipi_csi2 = &vep.bus.mipi_csi2;
-	lncfg->clk.pos = mipi_csi2->clock_lane;
-	lncfg->clk.pol = mipi_csi2->lane_polarities[0];
 	lncfg->num_data = mipi_csi2->num_data_lanes;
+	lncfg->cphy = vep.bus_type == V4L2_MBUS_CSI2_CPHY;
+
+	if (!lncfg->cphy) {
+		lncfg->clk.pos = mipi_csi2->clock_lane;
+		lncfg->clk.pol = mipi_csi2->lane_polarities[0];
+	}
 
 	lncfg->data = devm_kcalloc(dev,
 				   lncfg->num_data, sizeof(*lncfg->data),

-- 
2.51.0
Re: [PATCH RFC 2/8] media: qcom: camss: csiphy: Introduce C-PHY
Posted by Bryan O'Donoghue 3 months ago 
On 09/11/2025 09:39, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <david@ixit.cz>
> 
> Read C-PHY from the device-tree bus-type and save it into the csiphy
> structure for later use.
> 
> For C-PHY, skip clock line configuration, as there is none.
> 
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>   drivers/media/platform/qcom/camss/camss-csiphy.h | 2 ++
>   drivers/media/platform/qcom/camss/camss.c        | 8 ++++++--
>   2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/drivers/media/platform/qcom/camss/camss-csiphy.h
> index 895f80003c441..8f7d0e4c73075 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy.h
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.h
> @@ -28,11 +28,13 @@ struct csiphy_lane {
>   
>   /**
>    * struct csiphy_lanes_cfg - CSIPHY lanes configuration
> + * @cphy:     true if C-PHY is used, false if D-PHY is used
>    * @num_data: number of data lanes
>    * @data:     data lanes configuration
>    * @clk:      clock lane configuration (only for D-PHY)
>    */
>   struct csiphy_lanes_cfg {
> +	bool cphy;

Should be an integer from

include/dt-bindings/phy/phy.h

- PHY_TYPE_DPHY
- PHY_TYPE_CPHY

this should be indicated in the dt and latched here.

---
bod
Re: [PATCH RFC 2/8] media: qcom: camss: csiphy: Introduce C-PHY
Posted by David Heidelberg 2 months, 4 weeks ago 
On 10/11/2025 12:35, Bryan O'Donoghue wrote:
> On 09/11/2025 09:39, David Heidelberg via B4 Relay wrote:
>> From: David Heidelberg <david@ixit.cz>
>>
>> Read C-PHY from the device-tree bus-type and save it into the csiphy
>> structure for later use.
>>
>> For C-PHY, skip clock line configuration, as there is none.
>>
>> Signed-off-by: David Heidelberg <david@ixit.cz>
>> ---
>>   drivers/media/platform/qcom/camss/camss-csiphy.h | 2 ++
>>   drivers/media/platform/qcom/camss/camss.c        | 8 ++++++--
>>   2 files changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/ 
>> drivers/media/platform/qcom/camss/camss-csiphy.h
>> index 895f80003c441..8f7d0e4c73075 100644
>> --- a/drivers/media/platform/qcom/camss/camss-csiphy.h
>> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.h
>> @@ -28,11 +28,13 @@ struct csiphy_lane {
>>   /**
>>    * struct csiphy_lanes_cfg - CSIPHY lanes configuration
>> + * @cphy:     true if C-PHY is used, false if D-PHY is used
>>    * @num_data: number of data lanes
>>    * @data:     data lanes configuration
>>    * @clk:      clock lane configuration (only for D-PHY)
>>    */
>>   struct csiphy_lanes_cfg {
>> +    bool cphy;
> 
> Should be an integer from
> 
> include/dt-bindings/phy/phy.h
> 
> - PHY_TYPE_DPHY
> - PHY_TYPE_CPHY
> 
> this should be indicated in the dt and latched here.

Would it make sense to rather use the int from:

include/dt-bindings/media/video-interfaces.h

  - MEDIA_BUS_TYPE_CSI2_CPHY
  - MEDIA_BUS_TYPE_CSI2_DPHY
  - ...

?

This one is always used with the endpoint bus-type.

David

> 
> ---
> bod

-- 
David Heidelberg
Re: [PATCH RFC 2/8] media: qcom: camss: csiphy: Introduce C-PHY
Posted by Bryan O'Donoghue 2 months, 4 weeks ago 
On 12/11/2025 16:15, David Heidelberg wrote:
>> Should be an integer from
>>
>> include/dt-bindings/phy/phy.h
>>
>> - PHY_TYPE_DPHY
>> - PHY_TYPE_CPHY
>>
>> this should be indicated in the dt and latched here.
> 
> Would it make sense to rather use the int from:
> 
> include/dt-bindings/media/video-interfaces.h
> 
>   - MEDIA_BUS_TYPE_CSI2_CPHY
>   - MEDIA_BUS_TYPE_CSI2_DPHY
>   - ...
> 
> ?
Maybe, but surely you need to get the mode of the PHY from DT ?

I'm fine with the MEDIA_BUS_TYPE but, I do think the logic must be DT 
driven.

---
bod
Re: [PATCH RFC 2/8] media: qcom: camss: csiphy: Introduce C-PHY
Posted by Casey Connolly 3 months ago 
Hi David,

On 11/9/25 10:39, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <david@ixit.cz>
> 
> Read C-PHY from the device-tree bus-type and save it into the csiphy
> structure for later use.
> 
> For C-PHY, skip clock line configuration, as there is none.
> 
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>   drivers/media/platform/qcom/camss/camss-csiphy.h | 2 ++
>   drivers/media/platform/qcom/camss/camss.c        | 8 ++++++--
>   2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/drivers/media/platform/qcom/camss/camss-csiphy.h
> index 895f80003c441..8f7d0e4c73075 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy.h
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.h
> @@ -28,11 +28,13 @@ struct csiphy_lane {
>   
>   /**
>    * struct csiphy_lanes_cfg - CSIPHY lanes configuration
> + * @cphy:     true if C-PHY is used, false if D-PHY is used
>    * @num_data: number of data lanes
>    * @data:     data lanes configuration
>    * @clk:      clock lane configuration (only for D-PHY)
>    */
>   struct csiphy_lanes_cfg {
> +	bool cphy;

Bit of a nit, but it would read better to use an enum here I think, then 
one doesn't have to infer that "!lncfg->cphy" means dphy mode.

Kind regards,
Casey (she/they)

>   	int num_data;
>   	struct csiphy_lane *data;
>   	struct csiphy_lane clk;
> diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
> index fcc2b2c3cba07..549780f3f948b 100644
> --- a/drivers/media/platform/qcom/camss/camss.c
> +++ b/drivers/media/platform/qcom/camss/camss.c
> @@ -4055,9 +4055,13 @@ static int camss_of_parse_endpoint_node(struct device *dev,
>   	csd->interface.csiphy_id = vep.base.port;
>   
>   	mipi_csi2 = &vep.bus.mipi_csi2;
> -	lncfg->clk.pos = mipi_csi2->clock_lane;
> -	lncfg->clk.pol = mipi_csi2->lane_polarities[0];
>   	lncfg->num_data = mipi_csi2->num_data_lanes;
> +	lncfg->cphy = vep.bus_type == V4L2_MBUS_CSI2_CPHY;
> +
> +	if (!lncfg->cphy) {
> +		lncfg->clk.pos = mipi_csi2->clock_lane;
> +		lncfg->clk.pol = mipi_csi2->lane_polarities[0];
> +	}
>   
>   	lncfg->data = devm_kcalloc(dev,
>   				   lncfg->num_data, sizeof(*lncfg->data),
>

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