Re: [PATCH v6 2/9] dt-bindings: phy: rockchip,rk3588-mipi-dcphy: Select TX or RX, add phy-type

[Michael Riesch <michael.riesch@collabora.com>]

Hi Jason,

Thanks for the patch.

On 11/10/26 09:18, Jason Yang wrote:
> The Samsung MIPI D-/C-PHY block on RK3588 and RK3576 has a transmitter
> for DSI and a receiver for CSI-2, and the DSI host and the CSI-2 host
> can use the transmitter and the receiver at the same time. The single
> cell of this binding selects the mode and refers to the transmitter, so
> the receiver cannot be described.
> 
> Change the cell to select the transmitter or the receiver. The
> transmitter and the receiver cannot operate in different modes [1], so
> the optional phy-type property of the PHY node sets the mode for the
> whole block, D-PHY by default:
> 
> 	/* the MIPI DSI host, driving the transmitter */
> 	phys = <&mipidcphy0 PHY_DIRECTION_TX>;
> 
> 	/* the MIPI CSI-2 host, driving the receiver */
> 	phys = <&mipidcphy0 PHY_DIRECTION_RX>;
> 
> For C-PHY the consumers stay the same and the PHY node gets:
> 
> 	phy-type = <PHY_TYPE_CPHY>;
> 
> Existing DTs on a newer kernel: PHY_TYPE_DPHY and PHY_TYPE_CPHY remain
> valid as deprecated values. They select the transmitter and imply
> phy-type = <PHY_TYPE_DPHY> or <PHY_TYPE_CPHY> respectively, so nothing
> changes for them.
> 
> New DTs on an older kernel: an ABI break. The older kernel ignores
> phy-type and takes any cell value as the mode of the block. A DSI node
> with PHY_DIRECTION_TX therefore gets no display, and a CSI-2 node with
> PHY_DIRECTION_RX gets no camera.
> 
> [1] RK3588 TRM: section 22.1 (overview): "The TX and RX only support
>     operate in the same PHY mode."
> 
> Suggested-by: Michael Riesch <michael.riesch@collabora.com>
> Link: https://lore.kernel.org/r/94d47cab-10c6-4ec3-84a0-3bddc9d67f5f@collabora.com
> Signed-off-by: Jason Yang <jason98166@gmail.com>

Reviewed-by: Michael Riesch <michael.riesch@collabora.com>

Best regards,
Michael

> ---
>  .../bindings/phy/rockchip,rk3588-mipi-dcphy.yaml       | 18 +++++++++++++++---
>  1 file changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/phy/rockchip,rk3588-mipi-dcphy.yaml b/Documentation/devicetree/bindings/phy/rockchip,rk3588-mipi-dcphy.yaml
> index c8ff5ba22a86..1ea21ab203ba 100644
> --- a/Documentation/devicetree/bindings/phy/rockchip,rk3588-mipi-dcphy.yaml
> +++ b/Documentation/devicetree/bindings/phy/rockchip,rk3588-mipi-dcphy.yaml
> @@ -22,11 +22,23 @@ properties:
>    "#phy-cells":
>      const: 1
>      description: |
> -      Argument is mode to operate in. Supported modes are:
> -        - PHY_TYPE_DPHY
> -        - PHY_TYPE_CPHY
> +      Argument defines whether receiver or transmitter PHY is used.
> +        - PHY_DIRECTION_TX
> +        - PHY_DIRECTION_RX
> +
> +      PHY_TYPE_DPHY and PHY_TYPE_CPHY are deprecated. They select the
> +      transmitter and imply phy-type = <PHY_TYPE_DPHY> or <PHY_TYPE_CPHY>
> +      respectively. Use PHY_DIRECTION_TX and phy-type instead.
> +
>        See include/dt-bindings/phy/phy.h for constants.
>  
> +  phy-type:
> +    description: D-PHY (default) or C-PHY mode
> +    enum:
> +      - 10 # PHY_TYPE_DPHY
> +      - 11 # PHY_TYPE_CPHY
> +    default: 10
> +
>    clocks:
>      maxItems: 2
>  
>