Re: [PATCH 9/9] drm/mediatek: add dpi dual edge support

Matthias Brugger
2019-01-09T16:58:54Z

On 04/01/2019 08:03, chunhui dai wrote:
> DPI sample on rising and falling edge. It can reduce half data io.
>
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: chunhui dai <chunhui.dai@mediatek.com>
> ---
> drivers/gpu/drm/mediatek/mtk_dpi.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 4a2f4a6..acb4f47 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -117,6 +117,7 @@ struct mtk_dpi_conf {
> unsigned int (*cal_factor)(int clock);
> u32 reg_h_fre_con;
> bool edge_sel_en;
> + bool dual_edge;
> };
>
> static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
> @@ -353,6 +354,15 @@ static void mtk_dpi_config_disable_edge(struct mtk_dpi *dpi)
> mtk_dpi_mask(dpi, dpi->conf->reg_h_fre_con, 0, EDGE_SEL_EN);
> }
>
> +static void mtk_dpi_config_dual_edge(struct mtk_dpi *dpi)

I think it is clearer if you rename the function to something like:
mtk_dpi_enable_dual_edge and call it in mtk_dpi_set_display_mode if
dpi->conf->dual_edge is true.

Regards,
Matthias

> +{
> + if (dpi->conf->dual_edge) {
> + mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN |
> + DDR_4PHASE, DDR_EN | DDR_4PHASE);
> + mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, EDGE_SEL, EDGE_SEL);
> + }
> +}
> +
> static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
> enum mtk_dpi_out_color_format format)
> {
> @@ -509,6 +519,7 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
> mtk_dpi_config_color_format(dpi, dpi->color_format);
> mtk_dpi_config_2n_h_fre(dpi);
> mtk_dpi_config_disable_edge(dpi);
> + mtk_dpi_config_dual_edge(dpi);
> mtk_dpi_sw_reset(dpi, false);
>
> return 0;
> @@ -669,6 +680,16 @@ static unsigned int mt2701_calculate_factor(int clock)
> return 1;
> }
>
> +static unsigned int mt8183_calculate_factor(int clock)
> +{
> + if (clock <= 27000)
> + return 8;
> + else if (clock <= 167000)
> + return 4;
> + else
> + return 2;
> +}
> +
> static const struct mtk_dpi_conf mt8173_conf = {
> .cal_factor = mt8173_calculate_factor,
> .reg_h_fre_con = 0xe0,
> @@ -680,6 +701,12 @@ static unsigned int mt2701_calculate_factor(int clock)
> .edge_sel_en = true,
> };
>
> +static const struct mtk_dpi_conf mt8183_conf = {
> + .cal_factor = mt8183_calculate_factor,
> + .reg_h_fre_con = 0xe0,
> + .dual_edge = true,
> +};
> +
> static int mtk_dpi_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -775,6 +802,9 @@ static int mtk_dpi_remove(struct platform_device *pdev)
> { .compatible = "mediatek,mt8173-dpi",
> .data = &mt8173_conf,
> },
> + { .compatible = "mediatek,mt8183-dpi",
> + .data = &mt8183_conf,
> + },
> { },
> };
>
>