diff mbox series

[v4,05/11] media: cadence: csi2rx: Fix stream data configuration

Message ID 20210915120240.21572-6-p.yadav@ti.com
State Superseded
Headers show
Series CSI2RX support on J721E | expand

Commit Message

Pratyush Yadav Sept. 15, 2021, 12:02 p.m. UTC
Firstly, there is no VC_EN bit present in the STREAM_DATA_CFG register.
Bit 31 is part of the VL_SELECT field. Remove it completely.

Secondly, it makes little sense to enable ith virtual channel for ith
stream. Sure, there might be a use-case that demands it. But there might
also be a use case that demands all streams to use the 0th virtual
channel. Prefer this case over the former because it is less arbitrary
and also makes it very clear what the limitations of the current driver
is instead of giving a false impression that multiple virtual channels
are supported.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---

(no changes since v1)

 drivers/media/platform/cadence/cdns-csi2rx.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Laurent Pinchart Oct. 6, 2021, 11:44 p.m. UTC | #1
Hi Pratyush,

Thank you for the patch.

On Wed, Sep 15, 2021 at 05:32:34PM +0530, Pratyush Yadav wrote:
> Firstly, there is no VC_EN bit present in the STREAM_DATA_CFG register.

> Bit 31 is part of the VL_SELECT field. Remove it completely.

> 

> Secondly, it makes little sense to enable ith virtual channel for ith

> stream. Sure, there might be a use-case that demands it. But there might

> also be a use case that demands all streams to use the 0th virtual

> channel. Prefer this case over the former because it is less arbitrary

> and also makes it very clear what the limitations of the current driver

> is instead of giving a false impression that multiple virtual channels

> are supported.


No issue with that. Hopefully we'll support multiple streams for real in
the not too distant future :-)

> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>


Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>


> ---

> 

> (no changes since v1)

> 

>  drivers/media/platform/cadence/cdns-csi2rx.c | 8 +++++---

>  1 file changed, 5 insertions(+), 3 deletions(-)

> 

> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c

> index 3730e8beee48..edd56c5f2e89 100644

> --- a/drivers/media/platform/cadence/cdns-csi2rx.c

> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c

> @@ -48,7 +48,6 @@

>  #define CSI2RX_STREAM_STATUS_RDY			BIT(31)

>  

>  #define CSI2RX_STREAM_DATA_CFG_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x008)

> -#define CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT		BIT(31)

>  #define CSI2RX_STREAM_DATA_CFG_VC_SELECT(n)		BIT((n) + 16)

>  

>  #define CSI2RX_STREAM_CFG_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x00c)

> @@ -286,8 +285,11 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)

>  		writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF,

>  		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));

>  

> -		writel(CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT |

> -		       CSI2RX_STREAM_DATA_CFG_VC_SELECT(i),

> +		/*

> +		 * Enable one virtual channel. When multiple virtual channels

> +		 * are supported this will have to be changed.

> +		 */

> +		writel(CSI2RX_STREAM_DATA_CFG_VC_SELECT(0),

>  		       csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));

>  

>  		writel(CSI2RX_STREAM_CTRL_START,


-- 
Regards,

Laurent Pinchart
diff mbox series

Patch

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 3730e8beee48..edd56c5f2e89 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -48,7 +48,6 @@ 
 #define CSI2RX_STREAM_STATUS_RDY			BIT(31)
 
 #define CSI2RX_STREAM_DATA_CFG_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x008)
-#define CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT		BIT(31)
 #define CSI2RX_STREAM_DATA_CFG_VC_SELECT(n)		BIT((n) + 16)
 
 #define CSI2RX_STREAM_CFG_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x00c)
@@ -286,8 +285,11 @@  static int csi2rx_start(struct csi2rx_priv *csi2rx)
 		writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF,
 		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
 
-		writel(CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT |
-		       CSI2RX_STREAM_DATA_CFG_VC_SELECT(i),
+		/*
+		 * Enable one virtual channel. When multiple virtual channels
+		 * are supported this will have to be changed.
+		 */
+		writel(CSI2RX_STREAM_DATA_CFG_VC_SELECT(0),
 		       csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
 
 		writel(CSI2RX_STREAM_CTRL_START,