Re: [PATCH v14 3/3] drm/mediatek: set dpi pin mode to gpio low to avoid leakage current

[Chun-Kuang Hu <chunkuang.hu@kernel.org>]

Hi, Jitao:

Jitao Shi <jitao.shi@mediatek.com> 於 2020年4月3日 週五 下午4:04寫道：
>
> Config dpi pins mode to output and pull low when dpi is disabled.
> Aovid leakage current from some dpi pins (Hsync Vsync DE ... ).

Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

>
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 31 ++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 087f5ce732e1..1e01254788d9 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -10,7 +10,9 @@
>  #include <linux/kernel.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/of_gpio.h>
>  #include <linux/of_graph.h>
> +#include <linux/pinctrl/consumer.h>
>  #include <linux/platform_device.h>
>  #include <linux/types.h>
>
> @@ -74,6 +76,9 @@ struct mtk_dpi {
>         enum mtk_dpi_out_yc_map yc_map;
>         enum mtk_dpi_out_bit_num bit_num;
>         enum mtk_dpi_out_channel_swap channel_swap;
> +       struct pinctrl *pinctrl;
> +       struct pinctrl_state *pins_gpio;
> +       struct pinctrl_state *pins_dpi;
>         int refcount;
>  };
>
> @@ -379,6 +384,9 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi)
>         if (--dpi->refcount != 0)
>                 return;
>
> +       if (dpi->pinctrl && dpi->pins_gpio)
> +               pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
> +
>         mtk_dpi_disable(dpi);
>         clk_disable_unprepare(dpi->pixel_clk);
>         clk_disable_unprepare(dpi->engine_clk);
> @@ -403,6 +411,9 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
>                 goto err_pixel;
>         }
>
> +       if (dpi->pinctrl && dpi->pins_dpi)
> +               pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
> +
>         mtk_dpi_enable(dpi);
>         return 0;
>
> @@ -705,6 +716,26 @@ static int mtk_dpi_probe(struct platform_device *pdev)
>         dpi->dev = dev;
>         dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev);
>
> +       dpi->pinctrl = devm_pinctrl_get(&pdev->dev);
> +       if (IS_ERR(dpi->pinctrl)) {
> +               dpi->pinctrl = NULL;
> +               dev_dbg(&pdev->dev, "Cannot find pinctrl!\n");
> +       }
> +       if (dpi->pinctrl) {
> +               dpi->pins_gpio = pinctrl_lookup_state(dpi->pinctrl, "sleep");
> +               if (IS_ERR(dpi->pins_gpio)) {
> +                       dpi->pins_gpio = NULL;
> +                       dev_dbg(&pdev->dev, "Cannot find pinctrl idle!\n");
> +               }
> +               if (dpi->pins_gpio)
> +                       pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
> +
> +               dpi->pins_dpi = pinctrl_lookup_state(dpi->pinctrl, "default");
> +               if (IS_ERR(dpi->pins_dpi)) {
> +                       dpi->pins_dpi = NULL;
> +                       dev_dbg(&pdev->dev, "Cannot find pinctrl active!\n");
> +               }
> +       }
>         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>         dpi->regs = devm_ioremap_resource(dev, mem);
>         if (IS_ERR(dpi->regs)) {
> --
> 2.21.0
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