On Mon, Sep 19, 2022 at 10:23:55AM +0000, Sakari Ailus wrote: > On Mon, Sep 19, 2022 at 12:08:44PM +0200, Marco Felsch wrote: > > On 22-09-18, Laurent Pinchart wrote: > > > On Fri, Sep 16, 2022 at 03:45:34PM +0200, Marco Felsch wrote: > > > > Add the bindings for the Toshiba TC358746 Parallel <-> MIPI-CSI bridge > > > > driver. > > > > > > > > Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx> > > > > Reviewed-by: Rob Herring <robh@xxxxxxxxxx> > > > > --- > > > > Changelog: > > > > > > > > v2: > > > > - addded Robs r-b > > > > - s/than/then/ > > > > - added hsync/vsync/bus-type, make hsync/vsync required > > > > - fix example indent > > > > > > > > .../bindings/media/i2c/toshiba,tc358746.yaml | 179 ++++++++++++++++++ > > > > 1 file changed, 179 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..1fa574400bc2 > > > > --- /dev/null > > > > +++ b/Documentation/devicetree/bindings/media/i2c/toshiba,tc358746.yaml > > > > @@ -0,0 +1,179 @@ > > > > +# 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 > > > > + > > > > +# 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 then the > > > > +# mclk rate must be at least: (2 * link-frequency) / 8 > > > > +# `------------------´ ^ > > > > +# internal PLL rate smallest possible mclk-div > > > > + "#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: > > > > + $ref: /schemas/graph.yaml#/$defs/port-base > > > > + description: Input port > > > > + > > > > + properties: > > > > + endpoint: > > > > + $ref: /schemas/media/video-interfaces.yaml# > > > > + unevaluatedProperties: false > > > > + > > > > + properties: > > > > + hsync-active: > > > > + enum: > > > > + - 0 # Hvalid active high > > > > + vsync-active: > > > > + enum: > > > > + - 0 # Vvalid active high > > > > + bus-type: > > > > + enum: > > > > + - 5 # Parallel > > > > + > > > > + required: > > > > + - hsync-active > > > > + - vsync-active > > > > > > Let's make bus-type required too, to prepare for BT.656 support. > > > > I would have done it when the BT.656 support is added. Since the BT.656 > > don't require the sync signals I would have made a descision: > > - either: hsync/vsync present -> parallel with external syncs, or > > - bus-type present -> parallel bus with embedded syncs. > > > > So we don't bother the system-integrator with specifying unnecessary > > properties. Also having v/hsync required in place with the bus-type (set > > to bt.656) can cause confusion about the final used mode. > > The V4L2 fwnode framework can guess the type of the bus but it's not > recommended to use the feature. Explicit bus types in DT indeed makes it easier for drivers, so if a device can support multiple bus types (even if not implemented yet in the corresponding drivers), the property should be there. > Why do you have hsync-active and vsync-active if both are always zero? Can > the hardware not support other configuration? -- Regards, Laurent Pinchart
