[PATCH v13 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver

[CK Hu]

Hi, Bo-Chen:

On Fri, 2022-07-01 at 14:28 +0800, Bo-Chen Chen wrote:
> From: Markus Schneider-Pargmann <msp at baylibre.com>
> 
> This patch adds a embedded displayport driver for the MediaTek mt8195
> SoC.
> 
> It supports the MT8195, the embedded DisplayPort units. It offers
> DisplayPort 1.4 with up to 4 lanes.
> 
> The driver creates a child device for the phy. The child device will
> never exist without the parent being active. As they are sharing a
> register range, the parent passes a regmap pointer to the child so
> that
> both can work with the same register range. The phy driver sets
> device
> data that is read by the parent to get the phy device that can be
> used
> to control the phy properties.
> 
> This driver is based on an initial version by
> Jitao shi <jitao.shi at mediatek.com>
> 
> Signed-off-by: Markus Schneider-Pargmann <msp at baylibre.com>
> Signed-off-by: Guillaume Ranquet <granquet at baylibre.com>
> Signed-off-by: Bo-Chen Chen <rex-bc.chen at mediatek.com>
> ---

[snip]

> +
> +static int mtk_dp_set_color_format(struct mtk_dp *mtk_dp,
> +				   enum dp_pixelformat color_format)
> +{
> +	u32 val;
> +
> +	/* update MISC0 */
> +	mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3034,
> +			   color_format << DP_TEST_COLOR_FORMAT_SHIFT,
> +			   DP_TEST_COLOR_FORMAT_MASK);
> +
> +	switch (color_format) {
> +	case DP_PIXELFORMAT_YUV422:
> +		val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_YCBCR422;
> +		break;
> +	case DP_PIXELFORMAT_RGB:
> +		val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_RGB;
> +		break;
> +	default:

The default case would never happen, remove it.

Regards,
CK

> +		drm_warn(mtk_dp->drm_dev, "Unsupported color format:
> %d\n",
> +			 color_format);
> +		return -EINVAL;
> +	}
> +
> +	mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_303C,
> +			   val, PIXEL_ENCODE_FORMAT_DP_ENC0_P0_MASK);
> +	return 0;
> +}
> +