[PATCH] media: i2c: adv748x: Fix video standard selection register setting

[PATCH] media: i2c: adv748x: Fix video standard selection register setting

[Kieran Bingham]

From: Koji Matsuoka <koji.matsuoka.xm@renesas.com>

By video decoder user's manual, the bit 2 in Video Standard
Selection register must be reserved with the value of 1.
This driver cleared it with 0 when writing back.
This patch corrects it.

Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
---
 drivers/media/i2c/adv748x/adv748x-afe.c | 3 ++-
 drivers/media/i2c/adv748x/adv748x.h     | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/adv748x/adv748x-afe.c b/drivers/media/i2c/adv748x/adv748x-afe.c
index 71714634efb0..c4d9ffc50702 100644
--- a/drivers/media/i2c/adv748x/adv748x-afe.c
+++ b/drivers/media/i2c/adv748x/adv748x-afe.c
@@ -151,7 +151,8 @@ static void adv748x_afe_set_video_standard(struct adv748x_state *state,
 					  int sdpstd)
 {
 	sdp_clrset(state, ADV748X_SDP_VID_SEL, ADV748X_SDP_VID_SEL_MASK,
-		   (sdpstd & 0xf) << ADV748X_SDP_VID_SEL_SHIFT);
+		   (sdpstd & 0xf) << ADV748X_SDP_VID_SEL_SHIFT |
+		   ADV748X_SDP_VID_RESERVED_BIT);
 }
 
 static int adv748x_afe_s_input(struct adv748x_afe *afe, unsigned int input)
diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
index b482c7fe6957..f1f513f4327b 100644
--- a/drivers/media/i2c/adv748x/adv748x.h
+++ b/drivers/media/i2c/adv748x/adv748x.h
@@ -265,6 +265,7 @@ struct adv748x_state {
 #define ADV748X_SDP_INSEL		0x00	/* user_map_rw_reg_00 */
 
 #define ADV748X_SDP_VID_SEL		0x02	/* user_map_rw_reg_02 */
+#define ADV748X_SDP_VID_RESERVED_BIT	0x04
 #define ADV748X_SDP_VID_SEL_MASK	0xf0
 #define ADV748X_SDP_VID_SEL_SHIFT	4
 
-- 
2.17.1

Re: [PATCH] media: i2c: adv748x: Fix video standard selection register setting

[Kieran Bingham]

Hi Matsuoka-san,

Thank you for the patch,

On 10/12/2018 12:07, Kieran Bingham wrote:
> From: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
> 
> By video decoder user's manual, the bit 2 in Video Standard
> Selection register must be reserved with the value of 1.
> This driver cleared it with 0 when writing back.
> This patch corrects it.

I could not find this reference directly in the decoders hardware manual
- but the bit is present in the user guide shown only as bit set by
default, and otherwise undocumented.

I'll update the commit message here to clarify things.


> Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
> ---
>  drivers/media/i2c/adv748x/adv748x-afe.c | 3 ++-
>  drivers/media/i2c/adv748x/adv748x.h     | 1 +
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/adv748x/adv748x-afe.c b/drivers/media/i2c/adv748x/adv748x-afe.c
> index 71714634efb0..c4d9ffc50702 100644
> --- a/drivers/media/i2c/adv748x/adv748x-afe.c
> +++ b/drivers/media/i2c/adv748x/adv748x-afe.c
> @@ -151,7 +151,8 @@ static void adv748x_afe_set_video_standard(struct adv748x_state *state,
>  					  int sdpstd)
>  {
>  	sdp_clrset(state, ADV748X_SDP_VID_SEL, ADV748X_SDP_VID_SEL_MASK,
> -		   (sdpstd & 0xf) << ADV748X_SDP_VID_SEL_SHIFT);
> +		   (sdpstd & 0xf) << ADV748X_SDP_VID_SEL_SHIFT |
> +		   ADV748X_SDP_VID_RESERVED_BIT);
>  }
>  
>  static int adv748x_afe_s_input(struct adv748x_afe *afe, unsigned int input)
> diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
> index b482c7fe6957..f1f513f4327b 100644
> --- a/drivers/media/i2c/adv748x/adv748x.h
> +++ b/drivers/media/i2c/adv748x/adv748x.h
> @@ -265,6 +265,7 @@ struct adv748x_state {
>  #define ADV748X_SDP_INSEL		0x00	/* user_map_rw_reg_00 */
>  
>  #define ADV748X_SDP_VID_SEL		0x02	/* user_map_rw_reg_02 */
> +#define ADV748X_SDP_VID_RESERVED_BIT	0x04

For a 'bit' I would rather use the BIT(n) macro.

I'll update here, and add a comment stating that this bit is otherwise
undocumented.

>  #define ADV748X_SDP_VID_SEL_MASK	0xf0
>  #define ADV748X_SDP_VID_SEL_SHIFT	4

--
Regards

Kieran