RE: [PATCH v13 1/2] media: dt-bindings: media: xilinx: Add Xilinx MIPI CSI-2 Rx Subsystem

Vishal Sagar
2020-05-27T11:53:12Z

Hi Laurent,

Thanks for reviewing this series.

> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Sent: Sunday, May 24, 2020 7:32 AM
> To: Vishal Sagar <vsagar@xilinx.com>
> Cc: Hyun Kwon <hyunk@xilinx.com>; mchehab@kernel.org;
> robh+dt@kernel.org; mark.rutland@arm.com; Michal Simek
> <michals@xilinx.com>; linux-media@vger.kernel.org;
> devicetree@vger.kernel.org; hans.verkuil@cisco.com; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Dinesh Kumar
> <dineshk@xilinx.com>; Sandip Kothari <sandipk@xilinx.com>; Luca Ceresoli
> <luca@lucaceresoli.net>; Jacopo Mondi <jacopo@jmondi.org>; Hyun Kwon
> <hyunk@xilinx.com>; Rob Herring <robh@kernel.org>
> Subject: Re: [PATCH v13 1/2] media: dt-bindings: media: xilinx: Add Xilinx MIPI
> CSI-2 Rx Subsystem
>
> Hi Vishal,
>
> Thank you for the patch.
>
> On Tue, May 12, 2020 at 08:49:46PM +0530, Vishal Sagar wrote:
> > Add bindings documentation for Xilinx MIPI CSI-2 Rx Subsystem.
> >
> > The Xilinx MIPI CSI-2 Rx Subsystem consists of a CSI-2 Rx controller,
> > a D-PHY in Rx mode and a Video Format Bridge.
> >
> > Signed-off-by: Vishal Sagar <vishal.sagar@xilinx.com>
> > Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > v13
> > - Based on Laurent's suggestions
> > - Fixed the datatypes values as minimum and maximum
> > - condition added for en-vcx property
> >
> > v12
> > - Moved to yaml format
> > - Update CSI-2 and D-PHY
> > - Mention that bindings for D-PHY not here
> > - reset -> video-reset
> >
> > v11
> > - Modify compatible string from 4.0 to 5.0
> >
> > v10
> > - No changes
> >
> > v9
> > - Fix xlnx,vfb description.
> > - s/Optional/Required endpoint property.
> > - Move data-lanes description from Ports to endpoint property section.
> >
> > v8
> > - Added reset-gpios optional property to assert video_aresetn
> >
> > v7
> > - Removed the control name from dt bindings
> > - Updated the example dt node name to csi2rx
> >
> > v6
> > - Added "control" after V4L2_CID_XILINX_MIPICSISS_ACT_LANES as
> > suggested by Luca
> > - Added reviewed by Rob Herring
> >
> > v5
> > - Incorporated comments by Luca Cersoli
> > - Removed DPHY clock from description and example
> > - Removed bayer pattern from device tree MIPI CSI IP
> > doesn't deal with bayer pattern.
> >
> > v4
> > - Added reviewed by Hyun Kwon
> >
> > v3
> > - removed interrupt parent as suggested by Rob
> > - removed dphy clock
> > - moved vfb to optional properties
> > - Added required and optional port properties section
> > - Added endpoint property section
> >
> > v2
> > - updated the compatible string to latest version supported
> > - removed DPHY related parameters
> > - added CSI v2.0 related property (including VCX for supporting upto 16
> > virtual channels).
> > - modified csi-pxl-format from string to unsigned int type where the value
> > is as per the CSI specification
> > - Defined port 0 and port 1 as sink and source ports.
> > - Removed max-lanes property as suggested by Rob and Sakari
> > .../bindings/media/xilinx/xlnx,csi2rxss.yaml | 226 ++++++++++++++++++
> > 1 file changed, 226 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.yaml
> > b/Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.yaml
> > new file mode 100644
> > index 000000000000..b0885f461785
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.yam
> > +++ l
> > @@ -0,0 +1,226 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/xilinx/xlnx,csi2rxss.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Xilinx MIPI CSI-2 Receiver Subsystem
> > +
> > +maintainers:
> > + - Vishal Sagar <vishal.sagar@xilinx.com>
> > +
> > +description: |
> > + The Xilinx MIPI CSI-2 Receiver Subsystem is used to capture MIPI
> > +CSI-2
> > + traffic from compliant camera sensors and send the output as AXI4
> > +Stream
> > + video data for image processing.
> > + The subsystem consists of a MIPI D-PHY in slave mode which captures
> > +the
> > + data packets. This is passed along the MIPI CSI-2 Rx IP which
> > +extracts the
> > + packet data. The optional Video Format Bridge (VFB) converts this
> > +data to
> > + AXI4 Stream video data.
> > + For more details, please refer to PG232 Xilinx MIPI CSI-2 Receiver
> Subsystem.
> > + Please note that this bindings includes only the MIPI CSI-2 Rx
> > +controller
> > + and Video Format Bridge and not D-PHY.
> > +
> > +properties:
> > + compatible:
> > + items:
> > + - enum:
> > + - xlnx,mipi-csi2-rx-subsystem-5.0
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + interrupts:
> > + maxItems: 1
> > +
> > + clocks:
> > + description: List of clock specifiers
> > + items:
> > + - description: AXI Lite clock
> > + - description: Video clock
> > +
> > + clock-names:
> > + items:
> > + - const: lite_aclk
> > + - const: video_aclk
> > +
> > + xlnx,csi-pxl-format:
> > + description: |
> > + This denotes the CSI Data type selected in hw design.
> > + Packets other than this data type (except for RAW8 and
> > + User defined data types) will be filtered out.
> > + Possible values are as below -
> > + 0x1e - YUV4228B
> > + 0x1f - YUV42210B
> > + 0x20 - RGB444
> > + 0x21 - RGB555
> > + 0x22 - RGB565
> > + 0x23 - RGB666
> > + 0x24 - RGB888
> > + 0x28 - RAW6
> > + 0x29 - RAW7
> > + 0x2a - RAW8
> > + 0x2b - RAW10
> > + 0x2c - RAW12
> > + 0x2d - RAW14
> > + 0x2e - RAW16
> > + 0x2f - RAW20
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - anyOf:
> > + - minimum: 0x1e
> > + - maximum: 0x24
> > + - minimum: 0x28
> > + - maximum: 0x2f
> > +
> > + xlnx,vfb:
> > + type: boolean
> > + description: Present when Video Format Bridge is enabled in IP
> > + configuration
> > +
> > + xlnx,en-csi-v2-0:
> > + type: boolean
> > + description: Present if CSI v2 is enabled in IP configuration.
> > +
> > + xlnx,en-vcx:
> > + type: boolean
> > + description: |
> > + When present, there are maximum 16 virtual channels, else only 4.
> > +
> > + xlnx,en-active-lanes:
> > + type: boolean
> > + description: |
> > + Present if the number of active lanes can be re-configured at
> > + runtime in the Protocol Configuration Register. Otherwise all lanes,
> > + as set in IP configuration, are always active.
> > +
> > + video-reset-gpios:
> > + description: Optional specifier for a GPIO that asserts video_aresetn.
> > + maxItems: 1
> > +
> > + ports:
> > + type: object
> > +
> > + properties:
> > + port@0:
> > + type: object
> > + description: |
> > + Input / sink port node, single endpoint describing the
> > + CSI-2 transmitter.
> > +
> > + properties:
> > + reg:
> > + const: 0
> > +
> > + endpoint:
> > + type: object
> > +
> > + properties:
> > +
> > + data-lanes:
> > + description: |
> > + This is required only in the sink port 0 endpoint which
> > + connects to MIPI CSI-2 source like sensor.
> > + The possible values are -
> > + 1 - For 1 lane enabled in IP.
> > + 1 2 - For 2 lanes enabled in IP.
> > + 1 2 3 - For 3 lanes enabled in IP.
> > + 1 2 3 4 - For 4 lanes enabled in IP.
> > + items:
> > + - const: 1
> > + - const: 2
> > + - const: 3
> > + - const: 4
> > +
> > + remote-endpoint: true
> > +
> > + required:
> > + - data-lanes
> > + - remote-endpoint
> > +
> > + additionalProperties: false
> > +
> > + additionalProperties: false
> > +
> > + port@1:
> > + type: object
> > + description: |
> > + Output / source port node, endpoint describing modules
> > + connected the CSI-2 receiver.
> > +
> > + properties:
> > +
> > + reg:
> > + const: 1
> > +
> > + endpoint:
> > + type: object
> > +
> > + properties:
> > +
> > + remote-endpoint: true
> > +
> > + required:
> > + - remote-endpoint
> > +
> > + additionalProperties: false
> > +
> > + additionalProperties: false
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - interrupts
> > + - clocks
> > + - clock-names
> > + - xlnx,csi-pxl-format
> > + - ports
> > +
> > +if:
> > + not:
> > + required:
> > + - xlnx,en-csi-v2-0
> > +then:
> > + properties:
> > + xlnx,en-vcx: false
>
> As I've just commented on v12, I think we should condition the xlnx,csi-pxl-
> format property to xlnx,vfb being set. xlnx,csi-pxl-format should be removed
> from the required properties above, and the following conditions added:
>
> allOf:
> - if:
> required:
> - xlnx,vfb
> then:
> required:
> - xlnx,csi-pxl-format
> else:
> properties:
> xlnx,csi-pxl-format: false
>
> - if:
> not:
> required:
> - xlnx,en-csi-v2-0
> then:
> properties:
> xlnx,en-vcx: false
>
> The 'allOf' is needed as you can't have two 'if' constructs at the top level.
>
Thanks for sharing the explanation for this.
Can you please share where I can get this info?

> Please however let me know if my understanding is wrong and xlnx,csi-pxl-
> format is needed even when xlnx,vfb is not set. In that case please ignore this
> change (but please add the ... below).
>

Ok. I will add ... in the end.

> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + #include <dt-bindings/gpio/gpio.h>
> > + xcsi2rxss_1: csi2rx@a0020000 {
> > + compatible = "xlnx,mipi-csi2-rx-subsystem-5.0";
> > + reg = <0x0 0xa0020000 0x0 0x10000>;
> > + interrupt-parent = <&gic>;
> > + interrupts = <0 95 4>;
> > + xlnx,csi-pxl-format = <0x2a>;
> > + xlnx,vfb;
> > + xlnx,en-active-lanes;
> > + xlnx,en-csi-v2-0;
> > + xlnx,en-vcx;
> > + clock-names = "lite_aclk", "video_aclk";
> > + clocks = <&misc_clk_0>, <&misc_clk_1>;
> > + video-reset-gpios = <&gpio 86 GPIO_ACTIVE_LOW>;
> > +
> > + ports {
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + port@0 {
> > + /* Sink port */
> > + reg = <0>;
> > + csiss_in: endpoint {
> > + data-lanes = <1 2 3 4>;
> > + /* MIPI CSI-2 Camera handle */
> > + remote-endpoint = <&camera_out>;
> > + };
> > + };
> > + port@1 {
> > + /* Source port */
> > + reg = <1>;
> > + csiss_out: endpoint {
> > + remote-endpoint = <&vproc_in>;
> > + };
> > + };
> > + };
> > + };
>
> YAML files usually end with
>
> ...
>
> on the last line to mark the end of file.
>

Ok I will add this to the end of the file.

> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> --
> Regards,
>
> Laurent Pinchart

Regards
Vishal Sagar