Re: [RFCv3 4/6] media: dt-bindings: add DS90UB954-Q1 video deserializer

From: Rob Herring
Date: Mon Feb 07 2022 - 14:42:05 EST

On Sun, Feb 06, 2022 at 12:59:37PM +0100, Luca Ceresoli wrote:
> Describe the Texas Instruments DS90UB954-Q1, a 2-input MIPI CSI-2 video
> deserializer with I2C Address Translator and remote GPIOs.
>
> Signed-off-by: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
>
> ---
>
> Changes RFCv2 -> RFCv3:
>
> - rewrite in yaml
> - use new layout based on remote-chips under the main deser node
> - new clock configuration based on common clock framework
>
> Changes RFCv1 -> RFCv2:
>
> - add explicit aliases for the FPD-link RX ports (optional)
> - add proper remote GPIO description
> ---
> .../bindings/media/i2c/ti,ds90ub954-q1.yaml | 235 ++++++++++++++++++
> MAINTAINERS | 6 +
> 2 files changed, 241 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/i2c/ti,ds90ub954-q1.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/i2c/ti,ds90ub954-q1.yaml b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub954-q1.yaml
> new file mode 100644
> index 000000000000..95dc3d22f5d8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub954-q1.yaml
> @@ -0,0 +1,235 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2019 Renesas Electronics Corp.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/i2c/ti,ds90ub954-q1.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments DS90UB954-Q1 dual video deserializer
> +
> +maintainers:
> + - Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
> +
> +description: |
> + The TI DS90UB954-Q1 is a MIPI CSI-2 video deserializer that forwards
> + video streams from up to two FPD-Link 3 connections to a MIPI CSI-2
> + output. It also allows access to remote I2C and GPIO.
> +
> +properties:
> + compatible:
> + const: ti,ds90ub954-q1
> +
> + reg:
> + description: |
> + main I2C slave address; optionally aliases for RX port registers and
> + remote serializers. The main address is mandatory and must be the
> + first, others are optional and fall back to defaults if not
> + specified. See "reg-names".

minItems: 1
maxItems: 5

> +
> + reg-names:
> + description: |
> + Names of I2C address used to communicate with the chip, must match
> + the "reg" values; mandatory if there are 2 or more addresses.
> + "main" is the main I2C address, used to access shared registers.
> + "rxport0" and "rxport1" are the I2C alias to access FPD-link RX
> + port specific registers; must not be used by other slaves on the
> + same bus. "ser0" and "ser1" are the I2C alias to access the remote
> + serializer connected on each FPD-link RX port; must not be used by
> + other slaves on the same bus.
> + minItems: 1
> + maxItems: 5
> + items:
> + - const: main
> + - const: rxport0
> + - const: rxport1
> + - const: ser0
> + - const: ser1
> +
> + clocks:
> + description: provider of the clock on the XIN/REFCLK pin
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + reset-gpios:
> + description: chip reset GPIO connected to PDB pin (active low)

maxItems: 1

> +
> + i2c-alias-pool:

Needs a type.

> + description: |
> + list of I2C addresses that are known to be available on the "local"
> + (SoC-to-deser) I2C bus; they will be picked at runtime and used as
> + aliases to reach remote I2C chips
> +
> + '#clock-cells':
> + description: |
> + the DS90UB954 provides the FPD line rate clock to the serializer
> + const: 0
> +
> + ports:
> + $ref: /schemas/graph.yaml#/properties/ports
> +
> + patternProperties:
> + '^port@[01]$':
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + description: FPD-Link RX port 0 (RIN0+/RIN0- pins)
> +
> + properties:
> + endpoint:
> + $ref: /schemas/media/video-interfaces.yaml#
> + unevaluatedProperties: false
> +
> + '^port@2$':
> + $ref: /schemas/graph.yaml#/properties/port
> + description: MIPI-CSI2 TX port
> +
> + remote-chips:
> + type: object
> +
> + properties:
> + '#address-cells':
> + const: 1
> + '#size-cells':
> + const: 0
> +
> + patternProperties:
> + '^remote-chip@([01]+)$':
> + type: object
> + $ref: /schemas/media/i2c/ti,ds90ub953-q1.yaml#
> +
> + required:
> + - '#address-cells'
> + - '#size-cells'
> +
> + additionalProperties: false
> +
> + i2c-atr:
> + description: |
> + Each child describes the I2C bus on the remote side of an RX port
> + type: object
> +
> + properties:
> + '#address-cells':
> + const: 1
> + '#size-cells':
> + const: 0
> +
> + patternProperties:
> + '^i2c@([01]+)$':

Only 0 or 1 is valid? Then drop the '+'.

This is an i2c bus, so you need:

$ref: /schemas/i2c-controller.yaml#'
unevaluatedProperties: false

> + type: object
> +
> + properties:
> + reg:
> + maxItems: 1

> + '#address-cells':
> + const: 1
> + '#size-cells':
> + const: 0

You can drop these as i2c-controller.yaml covers them.

> + clock-frequency:
> + minimum: 1

1 is already the minimum. (Well, maybe it is 0, but that's not really
useful.)

> + maximum: 1000000
> +
> + additionalProperties: false
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - ports
> + - remote-chips
> + - i2c-atr
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/media/ds90ub953.h>
> +
> + i2c@0 {
> + reg = <0x0 0x100>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + deser: deser@3d {
> + compatible = "ti,ds90ub954-q1";
> + reg-names = "main", "rxport0", "rxport1", "ser0", "ser1";
> + reg = <0x3d>, <0x40>, <0x41>, <0x44>, <0x45>;
> + clocks = <&clk_25M>;
> + interrupt-parent = <&gic>;
> + interrupts = <3 1 IRQ_TYPE_LEVEL_LOW>;
> + reset-gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
> +
> + #clock-cells = <0>;
> +
> + i2c-alias-pool = /bits/ 16 <0x4a 0x4b 0x4c 0x4d 0x4e 0x4f>;
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 {
> + reg = <0>;
> + ds90ub954_fpd3_in0: endpoint {
> + remote-endpoint = <&sensor_0_out>;
> + };
> + };
> +
> + port@2 {
> + reg = <2>;
> + ds90ub954_mipi_out0: endpoint {
> + data-lanes = <1 2 3 4>;
> + link-frequencies = /bits/ 64 <400000000>;
> + remote-endpoint = <&csirx_0_in>;
> + };
> + };
> + };
> +
> + remote-chips {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + des0_ser0: remote-chip@0 {
> + reg = <0>;
> + compatible = "ti,ds90ub953-q1";
> + clocks = <&deser>;
> + ti,gpio-functions =
> + <DS90_GPIO_FUNC_UNUSED
> + DS90_GPIO_FUNC_OUTPUT_REMOTE
> + DS90_GPIO_FUNC_UNUSED
> + DS90_GPIO_FUNC_UNUSED>;
> +
> + gpio-controller;
> + #gpio-cells = <2>;
> + #clock-cells = <0>;
> + };
> + };
> +
> + i2c-atr {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + remote_i2c0: i2c@0 {
> + reg = <0>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + sensor_0@1a {
> + compatible = "sony,imx274";
> + reg = <0x1a>;
> +
> + reset-gpios = <&des0_ser0 1 GPIO_ACTIVE_LOW>;
> +
> + port {
> + sensor_0_out: endpoint {
> + remote-endpoint = <&ds90ub954_fpd3_in0>;
> + };
> + };
> + };
> + };
> + };
> + };
> + };
> +
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4429ce035496..f0156062f788 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19097,6 +19097,12 @@ S: Maintained
> F: Documentation/devicetree/bindings/media/i2c/ti,ds90ub953-q1.yaml
> F: include/dt-bindings/media/ds90ub953.h
>
> +TEXAS INSTRUMENTS DS90UB954 VIDEO DESERIALIZER DRIVER
> +M: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
> +L: linux-media@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: Documentation/devicetree/bindings/media/i2c/ti,ds90ub954-q1.yaml
> +
> TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
> M: Nishanth Menon <nm@xxxxxx>
> M: Tero Kristo <kristo@xxxxxxxxxx>
> --
> 2.25.1
>
>