Hi Rasmus,
Quoting Rasmus Villemoes (2022-07-05 10:08:37)
> Hi
>
> I have an imx8mp board with a sn65dsi86 and a (full-size) DisplayPort
> connector, which I'm trying to get up and running.
>
> The display connector registers itself as a bridge; I do get
> successfully to the end of display_connector_probe(). But
> ti_sn_bridge_probe() only looks for a panel (passing NULL for the
> drm_bridge** argument), so always fails with -EPROBE_DEFER.
>
> This text
>
> At the moment, this binding only handles the eDP case. It is
> possible it will be extended in the future to handle the DP case.
> For DP, presumably a connector would be listed under the DP AUX
> bus instead of a panel.
>
> in dp-aux-bus.yaml suggests that what I'm trying to do is simply not
> supported yet. But then I stumbled on commit 5a6bca1ff7a5 (arm64: dts:
> renesas: falcon-cpu: Add DSI display output), which seems to do exactly
> what I'm trying to, except with a mini dp connector. So I must be
> missing something; maybe ti_sn_bridge_probe() failing is not actually a
> problem and I could be looking at the wrong place.
>
> Snippets from my .dts; the dp connector is currently placed at top
> level, i.e. not within an aux-bus node below the sn65dsi86:
>
> display_port0: connector {
> compatible = "dp-connector";
> label = "DP0";
> type = "full-size";
> dp-pwr-supply = <®_DP_PWR>;
>
> port {
> dp_connector_in: endpoint {
> remote-endpoint = <&sn65dsi86_out>;
> };
> };
> };
>
> &i2c5 {
> ...
> eDP: bridge@2c {
> compatible = "ti,sn65dsi86";
> reg = <0x2c>;
> pinctrl-names = "default";
> pinctrl-0 = <&pinctrl_eDP>;
>
> interrupts-extended = <&gpio3 14 IRQ_TYPE_LEVEL_HIGH>;
> enable-gpios = <&gpio3 9 GPIO_ACTIVE_HIGH>;
>
> vpll-supply = <&VDD_1V8>;
> vccio-supply = <&VDD_1V8>;
> vcca-supply = <®_1V2>;
> vcc-supply = <®_1V2>;
>
> clocks = <&clk_38_4MHz>;
> clock-names = "refclk";
>
> ports {
> #address-cells = <1>;
> #size-cells = <0>;
>
> port@0 {
> reg = <0>;
> sn65dsi86_in_a: endpoint {
> remote-endpoint = <&mipi_dsi_out>;
> };
> };
>
> port@1 {
> reg = <1>;
> sn65dsi86_out: endpoint {
> remote-endpoint = <&dp_connector_in>;
> data-lanes = <3 2 1 0>;
> };
> };
> };
> };
> };
>
> When I manually set the enable-gpio high in U-Boot, I can talk to the
> device and e.g. read out the 8 device_id bytes which match what I expect.
>
> Any hints would be highly appreciated.
If it helps, this is an area I've been working to support one of our
boards. I have a branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/kbingham/rcar.git
kbingham/drm-misc/next/sn65dsi86/hpd
But it's still a work in progress, and now needs rebasing to account for
Sam's latest updates.
I intend to resume this in a few weeks, but hopefully that branch may
have some helpful pointers to get things progressing for you too.
--
Kieran
>
> Thanks,
> Rasmus
