# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright (C) 2019 Renesas Electronics Corp.
%YAML 1.2
---
$id: http://devicetree.org/schemas/media/i2c/maxim,max9286.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Maxim Integrated Quad GMSL Deserializer
maintainers:
- Jacopo Mondi <jacopo+renesas@jmondi.org>
- Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
- Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
- Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
description: |
The MAX9286 deserializer receives video data on up to 4 Gigabit Multimedia
Serial Links (GMSL) and outputs them on a CSI-2 D-PHY port using up to 4 data
lanes.
In addition to video data, the GMSL links carry a bidirectional control
channel that encapsulates I2C messages. The MAX9286 forwards all I2C traffic
not addressed to itself to the other side of the links, where a GMSL
serializer will output it on a local I2C bus. In the other direction all I2C
traffic received over GMSL by the MAX9286 is output on the local I2C bus.
properties:
'#address-cells':
const: 1
'#size-cells':
const: 0
compatible:
const: maxim,max9286
reg:
description: I2C device address
maxItems: 1
poc-supply:
description: Regulator providing Power over Coax to all the ports
enable-gpios:
description: GPIO connected to the \#PWDN pin with inverted polarity
maxItems: 1
gpio-controller: true
'#gpio-cells':
const: 2
maxim,bus-width:
$ref: /schemas/types.yaml#/definitions/uint32
enum: [ 24, 27, 32 ]
description: |
The GMSL serial data bus width. This setting is normally controlled by
the BWS pin, but may be overridden with this property. The value must
match the configuration of the remote serializers.
maxim,i2c-remote-bus-hz:
enum: [ 8470, 28300, 84700, 105000, 173000, 339000, 533000, 837000 ]
default: 105000
description: |
The I2C clock frequency for the remote I2C buses. The value must match
the configuration of the remote serializers.
maxim,reverse-channel-microvolt:
minimum: 30000
maximum: 200000
default: 170000
description: |
Initial amplitude of the reverse control channel, in micro volts.
The initial amplitude shall be adjusted to a value compatible with the
configuration of the connected remote serializer.
Some camera modules (for example RDACM20) include an on-board MCU that
pre-programs the embedded serializer with power supply noise immunity
(high-threshold) enabled. A typical value of the deserializer's reverse
channel amplitude to communicate with pre-programmed serializers is
170000 micro volts.
A typical value for the reverse channel amplitude to communicate with
a remote serializer whose high-threshold noise immunity is not enabled
is 100000 micro volts
maxim,gpio-poc:
$ref: /schemas/types.yaml#/definitions/uint32-array
minItems: 2
maxItems: 2
description: |
Index of the MAX9286 gpio output line (0 or 1) that controls Power over
Coax to the cameras and its associated polarity flag.
The property accepts an array of two unsigned integers, the first being
the gpio line index (0 or 1) and the second being the gpio line polarity
flag (GPIO_ACTIVE_HIGH or GPIO_ACTIVE_LOW) as defined in
<include/dt-bindings/gpio/gpio.h>.
When the remote cameras power is controlled by one of the MAX9286 gpio
lines, this property has to be used to specify which line among the two
available ones controls the remote camera power enablement.
When this property is used it is not possible to register a gpio
controller as the gpio lines are controlled directly by the MAX9286 and
not available for consumers, nor the 'poc-supply' property should be
specified.
ports:
$ref: /schemas/graph.yaml#/properties/ports
properties:
port@0:
$ref: /schemas/graph.yaml#/properties/port
description: GMSL Input 0
port@1:
$ref: /schemas/graph.yaml#/properties/port
description: GMSL Input 1
port@2:
$ref: /schemas/graph.yaml#/properties/port
description: GMSL Input 2
port@3:
$ref: /schemas/graph.yaml#/properties/port
description: GMSL Input 3
port@4:
$ref: /schemas/graph.yaml#/$defs/port-base
unevaluatedProperties: false
description: CSI-2 Output
properties:
endpoint:
$ref: /schemas/media/video-interfaces.yaml#
unevaluatedProperties: false
properties:
data-lanes: true
required:
- data-lanes
required:
- port@4
i2c-mux:
type: object
$ref: /schemas/i2c/i2c-mux.yaml#
unevaluatedProperties: false
description: |
Each GMSL link is modelled as a child bus of an i2c bus multiplexer/switch.
patternProperties:
"^i2c@[0-3]$":
type: object
additionalProperties: false
description: |
Child node of the i2c bus multiplexer which represents a GMSL link.
Each serializer device on the GMSL link remote end is represented with
an i2c-mux child node. The MAX9286 chip supports up to 4 GMSL
channels.
properties:
reg:
description: The index of the GMSL channel.
maxItems: 1
'#address-cells':
const: 1
'#size-cells':
const: 0
patternProperties:
"^camera@[a-f0-9]+$":
type: object
description: |
The remote camera device, composed by a GMSL serializer and a
connected video source.
properties:
compatible:
description: The remote device compatible string.
reg:
minItems: 2
maxItems: 3
description: |
The I2C addresses to be assigned to the remote devices through
address reprogramming. The number of entries depends on the
requirements of the currently connected remote device.
port:
$ref: /schemas/graph.yaml#/properties/port
description: Connection to the MAX9286 sink.
required:
- compatible
- reg
- port
additionalProperties: false
patternProperties:
"^port[0-3]-poc-supply$":
description: Regulator providing Power over Coax for a particular port
required:
- compatible
- reg
- ports
- i2c-mux
allOf:
# Only one way of specifying power supplies is allowed: 'maxim,gpio-poc',
# 'poc-supply' or per-port poc-supply. Additionally, if 'maxim,gpio-poc' is
# present, then 'gpio-controller' isn't allowed.
- if:
required:
- maxim,gpio-poc
then:
properties:
poc-supply: false
gpio-controller: false
patternProperties:
"^port[0-3]-poc-supply$": false
- if:
required:
- poc-supply
then:
patternProperties:
"^port[0-3]-poc-supply$": false
additionalProperties: false
examples:
- |
#include <dt-bindings/gpio/gpio.h>
i2c@e66d8000 {
#address-cells = <1>;
#size-cells = <0>;
reg = <0 0xe66d8000>;
gmsl-deserializer@2c {
compatible = "maxim,max9286";
reg = <0x2c>;
poc-supply = <&camera_poc_12v>;
enable-gpios = <&gpio 13 GPIO_ACTIVE_HIGH>;
gpio-controller;
#gpio-cells = <2>;
maxim,i2c-remote-bus-hz = <339000>;
maxim,reverse-channel-microvolt = <170000>;
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
max9286_in0: endpoint {
remote-endpoint = <&rdacm20_out0>;
};
};
port@1 {
reg = <1>;
max9286_in1: endpoint {
remote-endpoint = <&rdacm20_out1>;
};
};
port@2 {
reg = <2>;
max9286_in2: endpoint {
remote-endpoint = <&rdacm20_out2>;
};
};
port@3 {
reg = <3>;
max9286_in3: endpoint {
remote-endpoint = <&rdacm20_out3>;
};
};
port@4 {
reg = <4>;
max9286_out: endpoint {
data-lanes = <1 2 3 4>;
remote-endpoint = <&csi40_in>;
};
};
};
i2c-mux {
#address-cells = <1>;
#size-cells = <0>;
i2c@0 {
#address-cells = <1>;
#size-cells = <0>;
reg = <0>;
camera@51 {
compatible = "imi,rdacm20";
reg = <0x51>, <0x61>;
port {
rdacm20_out0: endpoint {
remote-endpoint = <&max9286_in0>;
};
};
};
};
i2c@1 {
#address-cells = <1>;
#size-cells = <0>;
reg = <1>;
camera@52 {
compatible = "imi,rdacm20";
reg = <0x52>, <0x62>;
port {
rdacm20_out1: endpoint {
remote-endpoint = <&max9286_in1>;
};
};
};
};
i2c@2 {
#address-cells = <1>;
#size-cells = <0>;
reg = <2>;
camera@53 {
compatible = "imi,rdacm20";
reg = <0x53>, <0x63>;
port {
rdacm20_out2: endpoint {
remote-endpoint = <&max9286_in2>;
};
};
};
};
i2c@3 {
#address-cells = <1>;
#size-cells = <0>;
reg = <3>;
camera@54 {
compatible = "imi,rdacm20";
reg = <0x54>, <0x64>;
port {
rdacm20_out3: endpoint {
remote-endpoint = <&max9286_in3>;
};
};
};
};
};
};
/*
* Example of a deserializer that controls the camera Power over Coax
* through one of its gpio lines.
*/
gmsl-deserializer@6c {
compatible = "maxim,max9286";
reg = <0x6c>;
enable-gpios = <&gpio 14 GPIO_ACTIVE_HIGH>;
/*
* The remote camera power is controlled by MAX9286 GPIO line #0.
* No 'poc-supply' nor 'gpio-controller' are specified.
*/
maxim,gpio-poc = <0 GPIO_ACTIVE_LOW>;
/*
* Do not describe connections as they're the same as in the previous
* example.
*/
ports {
#address-cells = <1>;
#size-cells = <0>;
port@4 {
reg = <4>;
};
};
i2c-mux {
#address-cells = <1>;
#size-cells = <0>;
};
};
};