[PATCH v9 3/4] dt-bindings: media: i2c: Add bindings for IMI RDACM2x

From: Kieran Bingham
Date: Tue May 12 2020 - 11:51:33 EST


From: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>

The IMI RDACM20 and IMI RDACM21 are Gigabit Multimedia Serial Link (GMSL) camera
capable of transmitting video and I2C control messages on a coax cable
physical link for automotive applications.

Document their device tree bindings.

Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>

---
v2:
- Provide imi vendor prefix
- Fix minor spelling

v3:
- update binding descriptions

v4:
- No change

v5:
- Specify optional third reg address for the MCU

v7:
[Jacopo]
- Rename to imi,rdacm2x-gmsl.yaml
- Exand bindings to describe RDACM21

v9:
[Jacopo]
- Rework 'compatible' property as suggested by Rob
- Re-order vendor prefixes ('g' comes before 'i' ... )
- Add Rob's tag

.../bindings/media/i2c/imi,rdacm2x-gmsl.yaml | 159 ++++++++++++++++++
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
2 files changed, 161 insertions(+)
create mode 100644 Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml b/Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml
new file mode 100644
index 000000000000..fe524490e6a2
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/imi,rdacm2x-gmsl.yaml
@@ -0,0 +1,159 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+# Copyright (C) 2019 Renesas Electronics Corp.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/imi,rdacm2x-gmsl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: IMI D&D RDACM20 and RDACM21 Automotive Camera Platforms
+
+maintainers:
+ - Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
+ - Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
+ - Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
+ - Niklas SÃderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
+
+description: -|
+ The IMI D&D RDACM20 and RDACM21 are GMSL-compatible camera designed for
+ automotive applications.
+
+ The RDACM20 camera module encloses a Maxim Integrated MAX9271 GMSL serializer,
+ coupled with an OV10635 image sensor and an embedded MCU. Both the MCU and
+ the image sensor are connected to the serializer local I2C bus and are
+ accessible by the host SoC by direct addressing.
+
+ The RDACM21 camera module encloses the same serializer, coupled with an
+ OV10640 image sensor and an OV490 ISP. Only the OV490 ISP is interfaced to
+ the serializer local I2C bus while the image sensor is not accessible from
+ the host SoC.
+
+ They both connect to a remote GMSL endpoint through a coaxial cable.
+
+ IMI RDACM20
+ +---------------+ +--------------------------------+
+ | GMSL | <- Video Stream | <- Video--------\ |
+ | |< === GMSL Link ====== >|MAX9271<- I2C bus-> <-->OV10635 |
+ | de-serializer | <- I2C messages -> | \<-->MCU |
+ +---------------+ +--------------------------------+
+
+ IMI RDACM21
+ +---------------+ +--------------------------------+
+ | GMSL | <- Video Stream | <- Video--------\ |
+ | |< === GMSL Link ====== >|MAX9271<- I2C bus-> <-->OV490 |
+ | | <- I2C messages -> | | |
+ | de-serializer | | OV10640 <-------| |
+ +---------------+ +--------------------------------+
+
+ Both camera modules serialize video data generated by the embedded camera
+ sensor on the GMSL serial channel to a remote GMSL de-serializer. They also
+ receive and transmit I2C messages encapsulated and transmitted on the GMSL
+ bidirectional control channel.
+
+ All I2C traffic received on the GMSL link not directed to the serializer is
+ propagated on the local I2C bus to the remote device there connected. All the
+ I2C traffic generated on the local I2C bus not directed to the serializer is
+ propagated to the remote de-serializer encapsulated in the GMSL control
+ channel.
+
+ The RDACM20 and RDACM21 DT node should be a direct child of the GMSL
+ deserializer's I2C bus corresponding to the GMSL link that the camera is
+ attached to.
+
+properties:
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+ compatible:
+ enum:
+ - imi,rdacm20
+ - imi,rdacm21
+
+ reg:
+ description: -|
+ I2C device addresses, the first to be assigned to the serializer, the
+ following ones to be assigned to the remote devices.
+
+ For RDACM20 the second entry of the property is assigned to the
+ OV10635 image sensor and the optional third one to the embedded MCU.
+
+ For RDACM21 the second entry is assigned to the OV490 ISP and the optional
+ third one ignored.
+
+ minItems: 2
+ maxItems: 3
+
+ port:
+ type: object
+ additionalProperties: false
+ description: -|
+ Connection to the remote GMSL endpoint are modelled using the OF graph
+ bindings in accordance with the video interface bindings defined in
+ Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+ The device node contains a single "port" child node with a single
+ "endpoint" sub-device.
+
+ properties:
+ endpoint:
+ type: object
+ additionalProperties: false
+
+ properties:
+ remote-endpoint:
+ description: -|
+ phandle to the remote GMSL endpoint sub-node in the remote node
+ port.
+ maxItems: 1
+
+ required:
+ - remote-endpoint
+
+ required:
+ - endpoint
+
+required:
+ - compatible
+ - reg
+ - port
+
+examples:
+ - |
+ i2c@e66d8000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ reg = <0 0xe66d8000 0 0x40>;
+
+ camera@31 {
+ compatible = "imi,rdacm20";
+ reg = <0x31>, <0x41>, <0x51>;
+
+ port {
+ rdacm20_out0: endpoint {
+ remote-endpoint = <&max9286_in0>;
+ };
+ };
+ };
+ };
+
+ - |
+ i2c@e66d8000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ reg = <0 0xe66d8000 0 0x40>;
+
+ camera@31 {
+ compatible = "imi,rdacm21";
+ reg = <0x31>, <0x41>;
+
+ port {
+ rdacm21_out0: endpoint {
+ remote-endpoint = <&max9286_in0>;
+ };
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index d3891386d671..f0f09a4c23ad 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -455,6 +455,8 @@ patternProperties:
description: ILI Technology Corporation (ILITEK)
"^img,.*":
description: Imagination Technologies Ltd.
+ "^imi,.*":
+ description: Integrated Micro-Electronics Inc.
"^incircuit,.*":
description: In-Circuit GmbH
"^inet-tek,.*":
--
2.25.1