Re: [V3, 3/4] Documentation: dt-bindings: media: Document bindings for DW MIPI CSI-2 Host

From: Eugen.Hristev
Date: Fri Jan 11 2019 - 10:29:11 EST




On 19.10.2018 15:52, Luis Oliveira wrote:
> Add bindings for Synopsys DesignWare MIPI CSI-2 host.
>
> Signed-off-by: Luis Oliveira <lolivei@xxxxxxxxxxxx>
> ---
> Changelog
> v2-V3
> - removed IPI settings
>
> .../devicetree/bindings/media/snps,dw-csi-plat.txt | 52 ++++++++++++++++++++++
> 1 file changed, 52 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/snps,dw-csi-plat.txt
>
> diff --git a/Documentation/devicetree/bindings/media/snps,dw-csi-plat.txt b/Documentation/devicetree/bindings/media/snps,dw-csi-plat.txt
> new file mode 100644
> index 0000000..be3da05
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/snps,dw-csi-plat.txt
> @@ -0,0 +1,52 @@
> +Synopsys DesignWare CSI-2 Host controller
> +
> +Description
> +-----------
> +
> +This HW block is used to receive image coming from an MIPI CSI-2 compatible
> +camera.
> +
> +Required properties:
> +- compatible: shall be "snps,dw-csi-plat"
> +- reg : physical base address and size of the device memory mapped
> + registers;
> +- interrupts : CSI-2 Host interrupt
> +- snps,output-type : Core output to be used (IPI-> 0 or IDI->1 or BOTH->2)
> + These values choose which of the Core outputs will be used,
> + it can be Image Data Interface or Image Pixel Interface.
> +- phys : List of one PHY specifier (as defined in
> + Documentation/devicetree/bindings/phy/phy-bindings.txt).
> + This PHY is a MIPI DPHY working in RX mode.
> +- resets : Reference to a reset controller (optional)
> +
> +The per-board settings:
> + - port sub-node describing a single endpoint connected to the camera as
> + described in video-interfaces.txt[1].
> +
> +Example:
> +
> + csi2_1: csi2@3000 {
> + compatible = "snps,dw-csi-plat";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + reg = < 0x03000 0x7FF>;
> + interrupts = <2>;
> + output-type = <2>;
> + resets = <&dw_rst 1>;
> + phys = <&mipi_dphy_rx1 0>;
> + phy-names = "csi2-dphy";
> +
> + /* CSI-2 per-board settings */
> + port@1 {
> + reg = <1>;
> + csi1_ep1: endpoint {
> + remote-endpoint = <&camera_1>;
> + data-lanes = <1 2>;
> + };
> + };
> + port@2 {
> + csi1_ep2: endpoint {
> + remote-endpoint = <&vif1_ep>;

Hi again Luis,

Regarding the output endpoint, in your example port@2, if we use the
property snps,output-type=2 for example, so IDI output, which bus-type
you have in mind for this link? IDI is not documented in the
video-interfaces.txt binding.

Since the MIPI CSI-2 DPHY is actually between camera sensor and
csi2host, after this we can use either IDI or IPI if my understanding is
correct, and connect to a different pad/hw block which can further
handle these packets/pixels.

I am interested on how to specify the connection type between this
output pad and the next one (until a /dev/video can be registered by the
last driver for the last hw block).

Thanks,

Eugen

> + };
> + };
> + };
> --
> 2.7.4
>
>