On Fri, Feb 16, 2024 at 3:05 AM Alexander Stein
[off-list ref] wrote:

Hi all,

Am Samstag, 3. Februar 2024, 17:52:49 CET schrieb Adam Ford:

quoted

From: Lucas Stach <l.stach@pengutronix.de>

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@pengutronix.de>
Signed-off-by: Adam Ford <redacted>

---
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.yaml
b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
new file mode 100644
index 000000000000..3791c9f4ebab

--- /dev/null
+++

b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml

@@ -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@pengutronix.de>
+
+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.

adam

Best regards,
Alexander

quoted

+
+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>;
+              };
+          };
+        };
+    };

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