[PATCH v2 04/16] dt-bindings: display: ti,am65x-dss: Add ti,dpi-io-ctrl

[Tomi Valkeinen]

The DPI output pipeline in K3 SoCs contains the display subsystem (DSS)
which produces the in-SoC parallel video signal, and a DPI block which
adjusts the signal to the external MIPI DPI output.

The DSS IP has registers to configure whether the data and sync signals
are driven on rising or falling clock edge, and on some SoCs these are
automatically conveyed to the DPI block which needs that configuration
to properly output the MIPI DPI signal.

However, on some SoCs the DPI block configuration has to be done
manually, using an extra register outside the DSS, DPI0_CLK_CTRL in
MAIN_CTRL_MMR_CFG0 block, which controls the DPI block's behavior.

Currently the DPI0_CLK_CTRL is never written, so it's always 0, meaning
the data and sync are always driven on a rising clock edge regardless of
the DSS configuration.

Add 'ti,dpi-io-ctrl' property, which contains phandle to the
MAIN_CTRL_MMR_CFG0 block and the offset to the DPI0_CLK_CTRL register,
so that the DSS driver can configure the data and sync signals
correctly.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
---
 .../devicetree/bindings/display/ti/ti,am65x-dss.yaml          | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
index 588d72d4ec0d..902ae2122d86 100644
--- a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
+++ b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
@@ -113,6 +113,17 @@ properties:
       and OLDI_CLK_IO_CTRL registers. This property is needed for OLDI
       interface to work.
 
+  ti,dpi-io-ctrl:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description:
+      phandle to a syscon device node containing the DPI0_CLK_CTRL register,
+      with the offset to DPI0_CLK_CTRL as an argument.
+    maxItems: 1
+    items:
+      items:
+        - description: phandle to the syscon node
+        - description: DPI0_CLK_CTRL register offset
+
   max-memory-bandwidth:
     $ref: /schemas/types.yaml#/definitions/uint32
     description:

-- 
2.43.0