Re: [PATCH v12 11/14] drm/mediatek: dpi: Add tvd_clk enable/disable flow

[CK Hu]

Hi, Bo-Chen:

On Mon, 2022-06-20 at 20:10 +0800, Bo-Chen Chen wrote:
> We should enable/disable tvd_clk when power_on/power_off, so add this
> patch to do this.

Without this patch, what would happen?
It seems this patch is redundant for these SoCs:

static const struct of_device_id mtk_dpi_of_ids[] = {
	{ .compatible = "mediatek,mt2701-dpi",
	  .data = &mt2701_conf,
	},
	{ .compatible = "mediatek,mt8173-dpi",
	  .data = &mt8173_conf,
	},
	{ .compatible = "mediatek,mt8183-dpi",
	  .data = &mt8183_conf,
	},
	{ .compatible = "mediatek,mt8192-dpi",
	  .data = &mt8192_conf,
	},
	{ },
};

Regards,
CK


> 
> Signed-off-by: Bo-Chen Chen <rex-bc.chen@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c
> b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 2717b1741b7a..f83ecb154457 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -455,6 +455,7 @@ static void mtk_dpi_power_off(struct mtk_dpi
> *dpi)
>  	mtk_dpi_disable(dpi);
>  	clk_disable_unprepare(dpi->pixel_clk);
>  	clk_disable_unprepare(dpi->engine_clk);
> +	clk_disable_unprepare(dpi->tvd_clk);
>  }
>  
>  static int mtk_dpi_power_on(struct mtk_dpi *dpi)
> @@ -464,10 +465,16 @@ static int mtk_dpi_power_on(struct mtk_dpi
> *dpi)
>  	if (++dpi->refcount != 1)
>  		return 0;
>  
> +	ret = clk_prepare_enable(dpi->tvd_clk);
> +	if (ret) {
> +		dev_err(dpi->dev, "Failed to enable tvd pll: %d\n",
> ret);
> +		goto err_refcount;
> +	}
> +
>  	ret = clk_prepare_enable(dpi->engine_clk);
>  	if (ret) {
>  		dev_err(dpi->dev, "Failed to enable engine clock:
> %d\n", ret);
> -		goto err_refcount;
> +		goto err_engine;
>  	}
>  
>  	ret = clk_prepare_enable(dpi->pixel_clk);
> @@ -484,6 +491,8 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
>  
>  err_pixel:
>  	clk_disable_unprepare(dpi->engine_clk);
> +err_engine:
> +	clk_disable_unprepare(dpi->tvd_clk);
>  err_refcount:
>  	dpi->refcount--;
>  	return ret;