[PATCH v11 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver

CK Hu ck.hu at mediatek.com
Sun Jun 19 20:12:55 PDT 2022


On Fri, 2022-06-10 at 18:55 +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>
> [Bo-Chen: Cleanup the drivers and modify comments from reviewers]
> Signed-off-by: Bo-Chen Chen <rex-bc.chen at mediatek.com>
> ---

[snip]

> +
> +static void mtk_dp_calculate_pixrate(struct mtk_dp *mtk_dp)
> +{
> +	u8 target_frame_rate = 60;
> +	u32 target_pixel_clk;
> +	struct drm_display_mode mode;
> +	struct mtk_dp_timings *timings = &mtk_dp->info.timings;
> +
> +	drm_display_mode_from_videomode(&timings->vm, &mode);
> +
> +	if (mtk_dp->info.timings.frame_rate > 0) {
> +		target_frame_rate = mtk_dp->info.timings.frame_rate;
> +		target_pixel_clk = mode.htotal * mode.vtotal *
> +				   target_frame_rate;
> +	} else if (mtk_dp->info.timings.pix_rate_khz > 0) {
> +		target_pixel_clk = mtk_dp->info.timings.pix_rate_khz *
> 1000;
> +	} else {
> +		target_pixel_clk = mode.htotal * mode.vtotal *
> +				   target_frame_rate;
> +	}
> +
> +	mtk_dp->info.timings.pix_rate_khz = target_pixel_clk / 1000;

It seems that pix_rate_khz is used only here and does not used in
another place, so pix_rate_khz is useless, remove it.

Regards,
CK

> +}
> +




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