Re: [PATCH v5 3/7] drm: sun4i: dsi: Convert to bridge driver

[Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>]

Hi,

On Thu, Nov 25, 2021 at 7:45 PM Maxime Ripard <maxime@xxxxxxxxxx> wrote:
>
> On Wed, Nov 24, 2021 at 12:02:47AM +0530, Jagan Teki wrote:
> > > > > > > +     dsi->panel = of_drm_find_panel(remote);
> > > > > > > +     if (IS_ERR(dsi->panel)) {
> > > > > > > +             dsi->panel = NULL;
> > > > > > > +
> > > > > > > +             dsi->next_bridge = of_drm_find_bridge(remote);
> > > > > > > +             if (IS_ERR(dsi->next_bridge)) {
> > > > > > > +                     dev_err(dsi->dev, "failed to find bridge\n");
> > > > > > > +                     return PTR_ERR(dsi->next_bridge);
> > > > > > > +             }
> > > > > > > +     } else {
> > > > > > > +             dsi->next_bridge = NULL;
> > > > > > > +     }
> > > > > > > +
> > > > > > > +     of_node_put(remote);
> > > > > >
> > > > > > Using devm_drm_of_get_bridge would greatly simplify the driver
> > > > >
> > > > > I'm aware of this and this would break the existing sunxi dsi binding,
> > > > > we are not using ports based pipeline in dsi node. Of-course you have
> > > > > pointed the same before, please check below
> > > > > https://patchwork.kernel.org/project/dri-devel/patch/20210322140152.101709-2-jagan@xxxxxxxxxxxxxxxxxxxx/
> > > >
> > > > Then drm_of_find_panel_or_bridge needs to be adjusted to handle the DSI
> > > > bindings and look for a panel or bridge not only through the OF graph,
> > > > but also on the child nodes
> > >
> > > Okay. I need to check this.
> >
> > devm_drm_of_get_bridge is not working with legacy binding like the one
> > used in sun6i dsi
>
> There's nothing legacy about it.

What I'm mean legacy here with current binding used in sun6i-dsi like this.

&dsi {
          vcc-dsi-supply = <&reg_dcdc1>; /* VCC-DSI */
          status = "okay";

         panel@0 {
                   compatible = "bananapi,s070wv20-ct16-icn6211";
                   reg = <0>;
                   reset-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /*
LCD-RST: PL5 */
                  enable-gpios = <&pio 1 7 GPIO_ACTIVE_HIGH>; /*
LCD-PWR-EN: PB7 */
                  backlight = <&backlight>;
        };
};

devm_drm_of_get_bridge cannot find the device with above binding and
able to find the device with below binding.

&dsi {
       vcc-dsi-supply = <&reg_dcdc1>; /* VCC-DSI */
       status = "okay";

      ports {
            #address-cells = <1>;
            #size-cells = <0>;

           dsi_out: port@0 {
                   reg = <0>;

                  dsi_out_bridge: endpoint {
                            remote-endpoint = <&bridge_out_dsi>;
                  };
           };
      };

      panel@0 {
             compatible = "bananapi,s070wv20-ct16-icn6211";
             reg = <0>;
             reset-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /* LCD-RST: PL5 */
             enable-gpios = <&pio 1 7 GPIO_ACTIVE_HIGH>; /* LCD-PWR-EN: PB7 */
             backlight = <&backlight>;

              port {
                        bridge_out_dsi: endpoint {
                                remote-endpoint = <&dsi_out_bridge>;
                        };
                };
       };
};

>
> > https://patchwork.kernel.org/project/dri-devel/patch/20211122065223.88059-6-jagan@xxxxxxxxxxxxxxxxxxxx/
> >
> > dsi->next_bridge = devm_drm_of_get_bridge(dsi->dev, dsi->dev->of_node, 0, 0);
> > if (IS_ERR(dsi->next_bridge))
> >            return PTR_ERR(dsi->next_bridge);
> >
> > It is only working if we have ports on the pipeline, something like this
> > https://patchwork.kernel.org/project/dri-devel/patch/20210214194102.126146-8-jagan@xxxxxxxxxxxxxxxxxxxx/
> >
> > Please have a look and let me know if I miss anything?
>
> Yes, you're missing the answer you quoted earlier:

Yes, I'm trying to resolve the comment one after another. Will get back.

Thanks,
Jagan.