Re: [PATCH] tvp5150: Fix breakage for serial usage

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Mauro,

On Monday 25 January 2016 14:44:56 Mauro Carvalho Chehab wrote:
> changeset 460b6c0831cb ("tvp5150: Add s_stream subdev operation
> support") broke for em28xx-based devices with uses tvp5150. On those
> devices, touching the TVP5150_MISC_CTL register causes em28xx to stop
> streaming.
> 
> I suspect that it uses the 27 MHz clock provided by tvp5150 to feed
> em28xx. So, change the logic to do nothing on s_stream if the tvp5150 is
> not set up to work with V4L2_MBUS_PARALLEL.
> 
> Cc: Javier Martinez Canillas <javier@osg.samsung.com>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> ---
>  drivers/media/i2c/tvp5150.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
> index 437f1a7ecb96..779c6f453cc9 100644
> --- a/drivers/media/i2c/tvp5150.c
> +++ b/drivers/media/i2c/tvp5150.c
> @@ -975,19 +975,18 @@ static int tvp5150_g_mbus_config(struct v4l2_subdev
> *sd, static int tvp5150_s_stream(struct v4l2_subdev *sd, int enable)
>  {
>  	struct tvp5150 *decoder = to_tvp5150(sd);
> -	/* Output format: 8-bit ITU-R BT.656 with embedded syncs */
> -	int val = 0x09;
> 
>  	/* Output format: 8-bit 4:2:2 YUV with discrete sync */
> -	if (decoder->mbus_type == V4L2_MBUS_PARALLEL)
> -		val = 0x0d;
> +	if (decoder->mbus_type != V4L2_MBUS_PARALLEL)
> +		return 0;

This will break TVP5151 operation with the OMAP3 ISP in BT.656 mode. The OMAP3 
requires the TVP5151 to start and stop streaming when requested.

> 
>  	/* Initializes TVP5150 to its default values */
>  	/* # set PCLK (27MHz) */
>  	tvp5150_write(sd, TVP5150_CONF_SHARED_PIN, 0x00);
> 
> +	/* Output format: 8-bit ITU-R BT.656 with embedded syncs */
>  	if (enable)
> -		tvp5150_write(sd, TVP5150_MISC_CTL, val);
> +		tvp5150_write(sd, TVP5150_MISC_CTL, 0x09);
>  	else
>  		tvp5150_write(sd, TVP5150_MISC_CTL, 0x00);

-- 
Regards,

Laurent Pinchart