Re: [PATCH v2 7/7] drm/mediatek: mtk_dsi: Create connector for bridges

From: Laurent Pinchart
Date: Thu Apr 16 2020 - 13:35:44 EST


Hi Enric,

Thank you for the patch.

On Thu, Apr 16, 2020 at 05:57:19PM +0200, Enric Balletbo i Serra wrote:
> Use the drm_bridge_connector helper to create a connector for pipelines
> that use drm_bridge. This allows splitting connector operations across
> multiple bridges when necessary, instead of having the last bridge in
> the chain creating the connector and handling all connector operations
> internally.

That's the right direction, but this should be done in the mtk display
controller driver core, not in here. I'm OK with the code being here as
an interim measure if needed to move forward, but that should then be
temporary only.

> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> ---
>
> Changes in v2: None
>
> drivers/gpu/drm/mediatek/mtk_dsi.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 44718fa3d1ca..2f8876c32864 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -17,6 +17,7 @@
>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_bridge.h>
> +#include <drm/drm_bridge_connector.h>
> #include <drm/drm_mipi_dsi.h>
> #include <drm/drm_of.h>
> #include <drm/drm_panel.h>
> @@ -184,6 +185,7 @@ struct mtk_dsi {
> struct drm_bridge bridge;
> struct drm_bridge *panel_bridge;
> struct drm_bridge *next_bridge;
> + struct drm_connector *connector;
> struct phy *phy;
>
> void __iomem *regs;
> @@ -983,10 +985,19 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> */
> dsi->encoder.possible_crtcs = 1;
>
> - ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
> + ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> if (ret)
> goto err_cleanup_encoder;
>
> + dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
> + if (IS_ERR(dsi->connector)) {
> + DRM_ERROR("Unable to create bridge connector\n");
> + ret = PTR_ERR(dsi->connector);
> + goto err_cleanup_encoder;
> + }
> + drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> +
> return 0;
>
> err_cleanup_encoder:
> @@ -1144,6 +1155,7 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>
> dsi->bridge.funcs = &mtk_dsi_bridge_funcs;
> dsi->bridge.of_node = dev->of_node;
> + dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;

I think this line belongs to the patch that adds drm_bridge support to
this driver.

>
> drm_bridge_add(&dsi->bridge);
>

--
Regards,

Laurent Pinchart