Re: [PATCH 2/2] staging: media: imx: imx7-mipi-csic: Set PIXEL_MODE for YUV422

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

Hi Jacopo,

Thank you for the patch.

On Wed, Jan 19, 2022 at 12:20:24PM +0100, Jacopo Mondi wrote:
> Bits 13 and 12 of the ISP_CONFIGn register configure the PIXEL_MODE
> which specifies the sampling size, in pixel component units, on the
> CSI-2 output data interface when data are transferred to memory.
> 
> The register description in the chip manual specifies that DUAL mode
> should be used for YUV422 data but does not clarify the reason.
> 
> Todo: verify if other YUV formats require the same setting and what is the
> appropriate setting for RAW and sRGB formats.

I'll also test it on i.MX8MM, I recall I had to *not* set
PIXEL_MODE_DUAL on that platform for YUV to work.

> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> ---
>  drivers/staging/media/imx/imx7-mipi-csis.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
> index cb54bb7491d9..e96989c46479 100644
> --- a/drivers/staging/media/imx/imx7-mipi-csis.c
> +++ b/drivers/staging/media/imx/imx7-mipi-csis.c
> @@ -499,6 +499,10 @@ static void __mipi_csis_set_format(struct csi_state *state)
>  	/* Color format */
>  	val = mipi_csis_read(state, MIPI_CSIS_ISP_CONFIG_CH(0));
>  	val &= ~(MIPI_CSIS_ISPCFG_ALIGN_32BIT | MIPI_CSIS_ISPCFG_FMT_MASK);
> +
> +	if (state->csis_fmt->data_type == MIPI_CSI2_DATA_TYPE_YUV422_8)
> +		val |= MIPI_CSIS_ISPCFG_PIXEL_MODE_DUAL;
> +
>  	val |= MIPI_CSIS_ISPCFG_FMT(state->csis_fmt->data_type);
>  	mipi_csis_write(state, MIPI_CSIS_ISP_CONFIG_CH(0), val);
>  

-- 
Regards,

Laurent Pinchart