Hi Marco, On Thu, Sep 15, 2022 at 03:19:33PM +0200, Marco Felsch wrote: > On 22-09-05, Laurent Pinchart wrote: > > On Thu, Aug 18, 2022 at 04:33:06PM +0200, Marco Felsch wrote: > > > Add the bindings for the Toshiba TC358746 Parallel <-> MIPI-CSI bridge > > > driver. > > > > > > Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx> > > > --- > > > .../bindings/media/i2c/toshiba,tc358746.yaml | 157 ++++++++++++++++++ > > > 1 file changed, 157 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml > > > > > > diff --git a/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml b/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml > > > new file mode 100644 > > > index 000000000000..9783cca363c6 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml > > > @@ -0,0 +1,157 @@ > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/media/i2c/toshiba,tc358746.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Toshiba TC358746 Parallel to MIPI CSI2 Bridge > > > + > > > +maintainers: > > > + - Marco Felsch <kernel@xxxxxxxxxxxxxx> > > > + > > > +description: |- > > > + The Toshiba TC358746 converts a parallel video stream into a MIPI CSI-2 > > > + stream. The direction can be either parallel-in -> csi-out or csi-in -> > > > + parallel-out The chip is programmable trough I2C and SPI but the SPI > > > + interface is only supported in parallel-in -> csi-out mode. > > > + > > > + Note that the current device tree bindings only support the > > > + parallel-in -> csi-out path. > > > + > > > +properties: > > > + compatible: > > > + const: toshiba,tc358746 > > > + > > > + reg: > > > + maxItems: 1 > > > + > > > + clocks: > > > + description: > > > + The phandle to the reference clock source. This corresponds to the > > > + hardware pin REFCLK. > > > + maxItems: 1 > > > + > > > + clock-names: > > > + const: refclk > > > > As there's a single clock, should we omit the clock name ? > > Don't know, I would rather keep it to make it explicite. Many other go > that way too. I don't mind either way. > > > +# The bridge can act as clock provider for the sensor. To enable this support > > > +# #clock-cells must be specified. Attention if this feature is used than the > > > > s/than/then/ > > Sure, thanks. > > > > +# mclk rate must be at least: (2 * link-frequency) / 8 > > > +# `------------------´ ^ > > > +# internal PLL rate smallest possible mclk-div > > > > Could this be captured in the description of the property instead of a > > comment ? > > Hm.. a few (1,2) bindings using comments like this but I'm not against > it. If it belongs to the description, which property should I use? Since > there is no: clock-controller property like gpio-controller or > interrupt-controller. The clock provider will be activated based on the > #clock-cells property. But this property has nothing to with the > description since this property specifies the cell size. I would have put it in the description of the #clock-cells property: "#clock-cells": description: | The bridge can act as clock provider for the sensor. To enable this support #clock-cells must be specified. Attention ... const: 0 but if it becomes an issue, I'm OK with the comment too. > > > + "#clock-cells": > > > + const: 0 > > > + > > > + clock-output-names: > > > + description: > > > + The clock name of the MCLK output, the default name is tc358746-mclk. > > > + maxItems: 1 > > > + > > > + vddc-supply: > > > + description: Digital core voltage supply, 1.2 volts > > > + > > > + vddio-supply: > > > + description: Digital I/O voltage supply, 1.8 volts > > > + > > > + vddmipi-supply: > > > + description: MIPI CSI phy voltage supply, 1.2 volts > > > + > > > + reset-gpios: > > > + description: > > > + The phandle and specifier for the GPIO that controls the chip reset. > > > + This corresponds to the hardware pin RESX which is physically active low. > > > + maxItems: 1 > > > + > > > + ports: > > > + $ref: /schemas/graph.yaml#/properties/ports > > > + properties: > > > + port@0: > > > + $ref: /schemas/graph.yaml#/properties/port > > > + description: Input port > > > > Are the H/V sync signal polarities fixed, or should they be specified > > here ? > > At the moment they are fixed. If the hardware supports different polarities, let's add them to the device tree binding, even if the driver only supports a single option at the moment. > I can describe it if you want. Thanks. > > Does the chip support external sync only, or also BT.656 ? In the > > latter case this needs a bus-type. > > Yes, the chip also supports BT.656 but the driver doesn't support it > yet. You're right, that we should make it explicite albeit it would a > bit overhead yet since the only mode is: parallel-in with externa syncs. Let's prepare for BT.656 support in the DT bindings, or we may regret it later :-) > > > + > > > + port@1: > > > + $ref: /schemas/graph.yaml#/$defs/port-base > > > + description: Output port > > > + > > > + properties: > > > + endpoint: > > > + $ref: /schemas/media/video-interfaces.yaml# > > > + unevaluatedProperties: false > > > + > > > + properties: > > > + data-lanes: > > > + minItems: 1 > > > + maxItems: 4 > > > + > > > + clock-noncontinuous: true > > > + link-frequencies: true > > > + > > > + required: > > > + - data-lanes > > > + - link-frequencies > > > + > > > + required: > > > + - port@0 > > > + - port@1 > > > + > > > +required: > > > + - compatible > > > + - reg > > > + - clocks > > > + - clock-names > > > + - vddc-supply > > > + - vddio-supply > > > + - vddmipi-supply > > > + - ports > > > + > > > +additionalProperties: false > > > + > > > +examples: > > > + - | > > > + #include <dt-bindings/gpio/gpio.h> > > > + > > > + i2c { > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + > > > + csi-bridge@e { > > > + compatible = "toshiba,tc358746"; > > > + reg = <0xe>; > > > + > > > + clocks = <&refclk>; > > > + clock-names = "refclk"; > > > + > > > + reset-gpios = <&gpio 2 GPIO_ACTIVE_LOW>; > > > + > > > + vddc-supply = <&v1_2d>; > > > + vddio-supply = <&v1_8d>; > > > + vddmipi-supply = <&v1_2d>; > > > + > > > + /* sensor mclk provider */ > > > + #clock-cells = <0>; > > > + > > > + ports { > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + > > > + /* Input */ > > > + port@0 { > > > + reg = <0>; > > > + tc358746_in: endpoint { > > > + remote-endpoint = <&sensor_out>; > > > + }; > > > > Wrong indentation here. > > Yes, thanks. > > > > + }; > > > + > > > + /* Output */ > > > + port@1 { > > > + reg = <1>; > > > + tc358746_out: endpoint { > > > + remote-endpoint = <&mipi_csi2_in>; > > > + data-lanes = <1 2>; > > > + clock-noncontinuous; > > > + link-frequencies = /bits/ 64 <216000000>; > > > + }; > > > + }; > > > + }; > > > + }; > > > + }; -- Regards, Laurent Pinchart
