Re: [PATCH v3 07/12] dt-bindings: Document the Rockchip MIPI RX D-PHY bindings

[Jacob Chen <jacob-chen@iotwrt.com>]

Hi all,

2017-12-12 0:45 GMT+08:00 Laurent Pinchart <laurent.pinchart@ideasonboard.com>:
> Hello Jacob,
>
> Thank you for the patch.
>
> On Wednesday, 6 December 2017 13:19:34 EET Jacob Chen wrote:
>> From: Jacob Chen <jacob2.chen@rock-chips.com>
>>
>> Add DT bindings documentation for Rockchip MIPI D-PHY RX
>>
>> Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
>> ---
>>  .../bindings/media/rockchip-mipi-dphy.txt          | 71 +++++++++++++++++++
>>  1 file changed, 71 insertions(+)
>>  create mode 100644
>> Documentation/devicetree/bindings/media/rockchip-mipi-dphy.txt
>>
>> diff --git a/Documentation/devicetree/bindings/media/rockchip-mipi-dphy.txt
>> b/Documentation/devicetree/bindings/media/rockchip-mipi-dphy.txt new file
>> mode 100644
>> index 000000000000..cef9450db051
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/rockchip-mipi-dphy.txt
>> @@ -0,0 +1,71 @@
>> +Rockchip SoC MIPI RX D-PHY
>> +-------------------------------------------------------------
>> +
>> +Required properties:
>> +
>> +- compatible: value should be one of the following
>> +    "rockchip,rk3288-mipi-dphy";
>> +    "rockchip,rk3399-mipi-dphy";
>> +- rockchip,grf: GRF regs.
>> +- bus-width : maximum number of data lanes supported (SoC specific);
>
> Bus width isn't a standard property, should this be rockchip,data-lanes or
> rockchip,#data-lanes ?

I forgot to remove it, it's no unnecessary now.

>
>> +- clocks : list of clock specifiers, corresponding to entries in
>> +                 clock-names property;
>> +- clock-names: required clock name.
>> +
>> +The device node should contain two 'port' child node, according to the
>
> s/child node/child nodes/
>
>> bindings
>> +defined in Documentation/devicetree/bindings/media/video-interfaces.txt.
>> +The first port should be connected to sensor nodes, and the second port
>> should be
>> +connected to isp node. The following are properties specific to those
>> nodes.
>> +
>> +endpoint node
>> +-------------
>> +
>> +- data-lanes : (required) an array specifying active physical MIPI-CSI2
>> +             data input lanes and their mapping to logical lanes; the
>> +             array's content is unused, only its length is meaningful;
>
> I assume this means that the D-PHY can't reroute lanes. I would mention that
> explicitly, and require that the data-lanes values start at one at are
> consecutive instead of ignoring them.
>
>> +Device node example
>> +-------------------
>> +
>> +    mipi_dphy_rx0: mipi-dphy-rx0 {
>> +        compatible = "rockchip,rk3399-mipi-dphy";
>> +        clocks = <&cru SCLK_MIPIDPHY_REF>,
>> +            <&cru SCLK_DPHY_RX0_CFG>,
>> +            <&cru PCLK_VIO_GRF>;
>> +        clock-names = "dphy-ref", "dphy-cfg", "grf";
>> +        power-domains = <&power RK3399_PD_VIO>;
>> +        bus-width = <4>;
>> +
>> +        ports {
>> +            #address-cells = <1>;
>> +            #size-cells = <0>;
>> +
>> +            port@0 {
>> +                reg = <0>;
>> +                #address-cells = <1>;
>> +                #size-cells = <0>;
>> +
>> +                mipi_in_wcam: endpoint@0 {
>> +                    reg = <0>;
>> +                    remote-endpoint = <&wcam_out>;
>> +                    data-lanes = <1 2>;
>> +                };
>> +                mipi_in_ucam: endpoint@1 {
>> +                    reg = <1>;
>> +                    remote-endpoint = <&ucam_out>;
>> +                    data-lanes = <1>;
>> +                };
>
> What do those two camera correspond to ? Can they be active at the same time,
> or do they use the same data lanes ? If they use the same data lanes, how does
> this work, is there a multiplexer on the board ?
>

They can not be active at the same time, and there is no multiplexer.
If they use the same mipi phy, then only one sensor is allowed to be actived.

See "MIPI Details" chapter
http://opensource.rock-chips.com/wiki_Rockchip-isp1

Let me enumerates soime hardware connections that is common in
rockchip tablet desgin.

rk3288:
-
  ISP0 --> mipi TX1/RX1 --> front sensor
           --> mipi RX0 --> rear sensor

-
  ISP0 --> parallel --> front sensor
           --> mipi RX0 --> rear sensor

rk3399
-
  mipi TX1/RX1 , mipi TX0 --> dual-mipi screen
  ISP0 --> mipi RX0 --> front sensor
                                --> rear sensor
-
  ISP1 --> mipi TX1/RX1 --> front sensor
  ISP0 --> mipi RX0 --> rear sensor


Only the last connection allow two sensor work at same time.


>> +            };
>> +
>> +            port@1 {
>> +                reg = <1>;
>> +                #address-cells = <1>;
>> +                #size-cells = <0>;
>> +
>> +                dphy_rx0_out: endpoint@0 {
>> +                    reg = <0>;
>> +                    remote-endpoint = <&isp0_mipi_in>;
>> +                };
>> +            };
>> +        };
>> +    };
>> \ No newline at end of file
>
> --
> Regards,
>
> Laurent Pinchart
>