[PATCH] drm: bridge: samsung-dsim: Add i.MX8M Plus support

Marcel Ziswiler marcel.ziswiler at toradex.com
Wed Nov 2 00:01:18 UTC 2022


Hi Marek

On Sun, 2022-10-16 at 00:07 +0200, Marek Vasut wrote:
> Add extras to support i.MX8M Plus. The main change is the removal of
> HS/VS/DE signal inversion in the LCDIFv3-DSIM glue logic, otherwise
> the implementation of this IP in i.MX8M Plus is very much compatible
> with the i.MX8M Mini/Nano one.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>

Reviewed-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>

I also tried to test it on Verdin iMX8M Plus but so far I was unable to make it work. Either I am still missing
some other pieces or I got the imx8mp.dtsi parts wrong. Do you have them available somewhere by any chance?

Thanks!

Cheers

Marcel

> ---
> Cc: Adam Ford <aford173 at gmail.com>
> Cc: Andrzej Hajda <andrzej.hajda at intel.com>
> Cc: Frieder Schrempf <frieder.schrempf at kontron.de>
> Cc: Inki Dae <inki.dae at samsung.com>
> Cc: Jagan Teki <jagan at amarulasolutions.com>
> Cc: Kyungmin Park <kyungmin.park at samsung.com>
> Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
> Cc: Marek Szyprowski <m.szyprowski at samsung.com>
> Cc: Matteo Lisi <matteo.lisi at engicam.com>
> Cc: Michael Nazzareno Trimarchi <michael at amarulasolutions.com>
> Cc: NXP Linux Team <linux-imx at nxp.com>
> Cc: Robert Foss <robert.foss at linaro.org>
> Cc: Seung-Woo Kim <sw0312.kim at samsung.com>
> Cc: Tim Harvey <tharvey at gateworks.com>
> Cc: Tommaso Merciai <tommaso.merciai at amarulasolutions.com>
> Cc: linux-amarula <linux-amarula at amarulasolutions.com>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-samsung-soc at vger.kernel.org
> To: dri-devel at lists.freedesktop.org
> ---
>  drivers/gpu/drm/bridge/samsung-dsim.c | 55 +++++++++++++++++++++------
>  include/drm/bridge/samsung-dsim.h     |  1 +
>  2 files changed, 44 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 012d8b6463ad6..cf40fd8813ff2 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -465,6 +465,7 @@ samsung_dsim_types[SAMSUNG_DSIM_TYPE_COUNT] = {
>         [SAMSUNG_DSIM_TYPE_EXYNOS5422] = &exynos5422_dsi_driver_data,
>         [SAMSUNG_DSIM_TYPE_EXYNOS5433] = &exynos5433_dsi_driver_data,
>         [SAMSUNG_DSIM_TYPE_IMX8MM] = &imx8mm_dsi_driver_data,
> +       [SAMSUNG_DSIM_TYPE_IMX8MP] = &imx8mm_dsi_driver_data,
>  };
>  
>  static inline struct samsung_dsim *host_to_dsi(struct mipi_dsi_host *h)
> @@ -1404,18 +1405,26 @@ static int samsung_dsim_atomic_check(struct drm_bridge *bridge,
>         struct samsung_dsim *dsi = bridge_to_dsi(bridge);
>         struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
>  
> +       /*
> +        * The i.MX8M Mini/Nano glue logic between LCDIF and DSIM
> +        * inverts HS/VS/DE sync signals polarity, therefore, while
> +        * i.MX 8M Mini Applications Processor Reference Manual Rev. 3, 11/2020
> +        * 13.6.3.5.2 RGB interface
> +        * i.MX 8M Nano Applications Processor Reference Manual Rev. 2, 07/2022
> +        * 13.6.2.7.2 RGB interface
> +        * both claim "Vsync, Hsync, and VDEN are active high signals.", the
> +        * LCDIF must generate inverted HS/VS/DE signals, i.e. active LOW.
> +        *
> +        * The i.MX8M Plus glue logic between LCDIFv3 and DSIM does not
> +        * implement the same behavior, therefore LCDIFv3 must generate
> +        * HS/VS/DE signals active HIGH.
> +        */
>         if (dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MM) {
> -               /**
> -                * FIXME:
> -                * At least LCDIF + DSIM needs active low sync,
> -                * but i.MX 8M Mini Applications Processor Reference Manual,
> -                * Rev. 3, 11/2020 says
> -                *
> -                * 13.6.3.5.2 RGB interface
> -                * Vsync, Hsync, and VDEN are active high signals.
> -                */
>                 adjusted_mode->flags |= (DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
>                 adjusted_mode->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
> +       } else if (dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MP) {
> +               adjusted_mode->flags &= ~(DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
> +               adjusted_mode->flags |= (DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
>         }
>  
>         return 0;
> @@ -1448,7 +1457,8 @@ static int samsung_dsim_attach(struct drm_bridge *bridge,
>          * Passing NULL to the previous bridge makes Exynos DSI drivers
>          * work which is exactly done before.
>          */
> -       if (!(dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MM))
> +       if (dsi->plat_data->hw_type != SAMSUNG_DSIM_TYPE_IMX8MM &&
> +           dsi->plat_data->hw_type != SAMSUNG_DSIM_TYPE_IMX8MP)
>                 previous = NULL;
>  
>         return drm_bridge_attach(bridge->encoder, dsi->out_bridge, previous,
> @@ -1649,7 +1659,11 @@ static const struct samsung_dsim_host_ops samsung_dsim_generic_host_ops = {
>         .unregister_host = samsung_dsim_unregister_host,
>  };
>  
> -static const struct drm_bridge_timings samsung_dsim_bridge_timings = {
> +static const struct drm_bridge_timings samsung_dsim_bridge_timings_de_high = {
> +       .input_bus_flags = DRM_BUS_FLAG_DE_HIGH,
> +};
> +
> +static const struct drm_bridge_timings samsung_dsim_bridge_timings_de_low = {
>         .input_bus_flags = DRM_BUS_FLAG_DE_LOW,
>  };
>  
> @@ -1733,9 +1747,17 @@ int samsung_dsim_probe(struct platform_device *pdev)
>  
>         dsi->bridge.funcs = &samsung_dsim_bridge_funcs;
>         dsi->bridge.of_node = dev->of_node;
> -       dsi->bridge.timings = &samsung_dsim_bridge_timings;
>         dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
>  
> +       /*
> +        * The i.MX8M Mini/Nano LCDIF-DSIM glue logic inverts DE signal
> +        * polarity, see comment in samsung_dsim_atomic_check().
> +        */
> +       if (dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MM)
> +               dsi->bridge.timings = &samsung_dsim_bridge_timings_de_low;
> +       else
> +               dsi->bridge.timings = &samsung_dsim_bridge_timings_de_high;
> +
>         if (dsi->plat_data->host_ops && dsi->plat_data->host_ops->register_host)
>                 ret = dsi->plat_data->host_ops->register_host(dsi);
>  
> @@ -1841,11 +1863,20 @@ static const struct samsung_dsim_plat_data samsung_dsim_imx8mm_pdata = {
>         .host_ops = &samsung_dsim_generic_host_ops,
>  };
>  
> +static const struct samsung_dsim_plat_data samsung_dsim_imx8mp_pdata = {
> +       .hw_type = SAMSUNG_DSIM_TYPE_IMX8MP,
> +       .host_ops = &samsung_dsim_generic_host_ops,
> +};
> +
>  static const struct of_device_id samsung_dsim_of_match[] = {
>         {
>                 .compatible = "fsl,imx8mm-mipi-dsim",
>                 .data = &samsung_dsim_imx8mm_pdata,
>         },
> +       {
> +               .compatible = "fsl,imx8mp-mipi-dsim",
> +               .data = &samsung_dsim_imx8mp_pdata,
> +       },
>         { /* sentinel. */ }
>  };
>  MODULE_DEVICE_TABLE(of, samsung_dsim_of_match);
> diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h
> index df3d030daec6a..3789f9dbb238b 100644
> --- a/include/drm/bridge/samsung-dsim.h
> +++ b/include/drm/bridge/samsung-dsim.h
> @@ -28,6 +28,7 @@ enum samsung_dsim_type {
>         SAMSUNG_DSIM_TYPE_EXYNOS5422,
>         SAMSUNG_DSIM_TYPE_EXYNOS5433,
>         SAMSUNG_DSIM_TYPE_IMX8MM,
> +       SAMSUNG_DSIM_TYPE_IMX8MP,
>         SAMSUNG_DSIM_TYPE_COUNT,
>  };


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