Re: [PATCH V8 09/12] dt-bindings: display: imx: add binding for i.MX8MP HDMI TX

[Alexander Stein]

Am Freitag, 16. Februar 2024, 12:31:12 CET schrieb Adam Ford:
> On Fri, Feb 16, 2024 at 3:05 AM Alexander Stein
> 
> <alexander.stein@xxxxxxxxxxxxxxx> wrote:
> > Hi all,
> > 
> > Am Samstag, 3. Februar 2024, 17:52:49 CET schrieb Adam Ford:
> > > From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> > > 
> > > The HDMI TX controller on the i.MX8MP SoC is a Synopsys designware IP
> > > core with a little bit of SoC integration around it.
> > > 
> > > Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> > > Signed-off-by: Adam Ford <aford173@xxxxxxxxx>
> > > 
> > > ---
> > > V3:  Change name and location to better idenfity as a bridge and
> > > 
> > >      HDMI 2.0a transmitter
> > >      
> > >      Fix typos and feedback from Rob and added ports.
> > > 
> > > ---
> > > 
> > >  .../display/bridge/fsl,imx8mp-hdmi-tx.yaml    | 102 ++++++++++++++++++
> > >  1 file changed, 102 insertions(+)
> > >  create mode 100644
> > > 
> > > Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
> > > 
> > > diff --git
> > > a/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.ya
> > > ml
> > > b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.ya
> > > ml
> > > new file mode 100644
> > > index 000000000000..3791c9f4ebab
> > > --- /dev/null
> > > +++
> > > b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.ya
> > > ml
> > > @@ -0,0 +1,102 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id:
> > > http://devicetree.org/schemas/display/bridge/fsl,imx8mp-hdmi-tx.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Freescale i.MX8MP DWC HDMI TX Encoder
> > > +
> > > +maintainers:
> > > +  - Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> > > +
> > > +description:
> > > +  The i.MX8MP HDMI transmitter is a Synopsys DesignWare
> > > +  HDMI 2.0a TX controller IP.
> > > +
> > > +allOf:
> > > +  - $ref: /schemas/display/bridge/synopsys,dw-hdmi.yaml#
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - fsl,imx8mp-hdmi-tx
> > > +
> > > +  reg-io-width:
> > > +    const: 1
> > > +
> > > +  clocks:
> > > +    maxItems: 4
> > > +
> > > +  clock-names:
> > > +    items:
> > > +      - const: iahb
> > > +      - const: isfr
> > > +      - const: cec
> > > +      - const: pix
> > > +
> > > +  power-domains:
> > > +    maxItems: 1
> > > +
> > > +  ports:
> > > +    $ref: /schemas/graph.yaml#/properties/ports
> > > +
> > > +    properties:
> > > +      port@0:
> > > +        $ref: /schemas/graph.yaml#/properties/port
> > > +        description: Parallel RGB input port
> > > +
> > > +      port@1:
> > > +        $ref: /schemas/graph.yaml#/properties/port
> > > +        description: HDMI output port
> > > +
> > > +    required:
> > > +      - port@0
> > > +      - port@1
> > 
> > Is this really correct that port@1 is required? AFAICS this host already
> > supports HPD and DDC by itself, so there is no need for a dedicated HDMI
> > connector.
> > With the current state of the drivers this output port is completely
> > ignored anyway. Yet it works for a lot of people.
> 
> One of the feedback responses Lucas got was that it was missing the
> reference to the HDMI connector, so I added it as a response to that
> feedback.  I have tried device trees with and without it, and it
> doesn't impact anything, but It seems like there may be a requirement
> for it.

Yes, I noticed as well. A specified connector is completely ignored.
One reason is that dw_hdmi_plat_data.output_port is unsed in drivers/gpu/drm/
bridge/imx/imx8mp-hdmi-tx.c. Another one is that without 
DRM_BRIDGE_ATTACH_NO_CONNECTOR support in drivers/gpu/drm/mxsfb/lcdif_drv.c 
nothing changes.

Best regards,
Alexander

> adam
> 
> > Best regards,
> > Alexander
> > 
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +  - clocks
> > > +  - clock-names
> > > +  - interrupts
> > > +  - power-domains
> > > +  - ports
> > > +
> > > +unevaluatedProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/clock/imx8mp-clock.h>
> > > +    #include <dt-bindings/interrupt-controller/irq.h>
> > > +    #include <dt-bindings/power/imx8mp-power.h>
> > > +
> > > +    hdmi@32fd8000 {
> > > +        compatible = "fsl,imx8mp-hdmi-tx";
> > > +        reg = <0x32fd8000 0x7eff>;
> > > +        interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
> > > +        clocks = <&clk IMX8MP_CLK_HDMI_APB>,
> > > +                 <&clk IMX8MP_CLK_HDMI_REF_266M>,
> > > +                 <&clk IMX8MP_CLK_32K>,
> > > +                 <&hdmi_tx_phy>;
> > > +        clock-names = "iahb", "isfr", "cec", "pix";
> > > +        power-domains = <&hdmi_blk_ctrl IMX8MP_HDMIBLK_PD_HDMI_TX>;
> > > +        reg-io-width = <1>;
> > > +        ports {
> > > +           #address-cells = <1>;
> > > +           #size-cells = <0>;
> > > +           port@0 {
> > > +             reg = <0>;
> > > +
> > > +             hdmi_tx_from_pvi: endpoint {
> > > +               remote-endpoint = <&pvi_to_hdmi_tx>;
> > > +             };
> > > +          };
> > > +
> > > +          port@1 {
> > > +            reg = <1>;
> > > +              hdmi_tx_out: endpoint {
> > > +                remote-endpoint = <&hdmi0_con>;
> > > +              };
> > > +          };
> > > +        };
> > > +    };
> > 
> > --
> > TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
> > Amtsgericht München, HRB 105018
> > Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
> > http://www.tq-group.com/


-- 
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/