[PATCH v5 1/2] dt-bindings: display: bridge: add TI TDP158

[Marc Gonzalez]

TDP158 is an AC-coupled DVI / HDMI to TMDS level shifting Redriver.
It supports DVI 1.0, HDMI 1.4b and 2.0b.
It supports 4 TMDS channels, HPD, and a DDC interface.
It supports dual power supply rails (1.1V on VDD, 3.3V on VCC)
for power reduction. Several methods of power management are
implemented to reduce overall power consumption.
It supports fixed receiver EQ gain using I2C or pin strap to
compensate for different lengths input cable or board traces.

Features

- AC-coupled TMDS or DisplayPort dual-mode physical layer input
to HDMI 2.0b TMDS physical layer output supporting up to 6Gbps
data rate, compatible with HDMI 2.0b electrical parameters
- DisplayPort dual-mode standard version 1.1
- Programmable fixed receiver equalizer up to 15.5dB
- Global or independent high speed lane control, pre-emphasis
and transmit swing, and slew rate control
- I2C or pin strap programmable
- Configurable as a DisplayPort redriver through I2C
- Full lane swap on main lanes
- Low power consumption (200 mW at 6Gbps, 8 mW in shutdown)

https://www.ti.com/lit/ds/symlink/tdp158.pdf

Like the TFP410, the TDP158 can be set up in 2 different ways:
1) hard-coding its configuration settings using pin-strapping resistors
2) placing it on an I2C bus, and defer set-up until run-time

The mode is selected via pin 8 = I2C_EN
I2C_EN high = I2C Control Mode
I2C_EN low  = Pin Strap Mode

On our board, I2C_EN is pulled high.

Reviewed-by: Rob Herring (Arm) <robh at kernel.org>
Signed-off-by: Marc Gonzalez <mgonzalez at freebox.fr>
---
 .../bindings/display/bridge/ti,tdp158.yaml         | 57 ++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/ti,tdp158.yaml b/Documentation/devicetree/bindings/display/bridge/ti,tdp158.yaml
new file mode 100644
index 0000000000000..1c522f72c4bae
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/ti,tdp158.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/ti,tdp158.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI TDP158 HDMI to TMDS Redriver
+
+maintainers:
+  - Arnaud Vrac <avrac at freebox.fr>
+  - Pierre-Hugues Husson <phhusson at freebox.fr>
+
+properties:
+  compatible:
+    const: ti,tdp158
+
+# The reg property is required if and only if the device is connected
+# to an I2C bus. In pin strap mode, reg must not be specified.
+  reg:
+    description: I2C address of the device
+
+# Pin 36 = Operation Enable / Reset Pin
+# OE = L: Power Down Mode
+# OE = H: Normal Operation
+# Internal weak pullup - device resets on H to L transitions
+  enable-gpios:
+    description: GPIO controlling bridge enable
+
+  vcc-supply:
+    description: Power supply 3.3V
+
+  vdd-supply:
+    description: Power supply 1.1V
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+
+    properties:
+      port at 0:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: Bridge input
+
+      port at 1:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: Bridge output
+
+    required:
+      - port at 0
+      - port at 1
+
+required:
+  - compatible
+  - vcc-supply
+  - vdd-supply
+  - ports
+
+additionalProperties: false

-- 
2.34.1