Re: [PATCH v5 2/8] dt-bindings: phy: rockchip,rk3588-mipi-dcphy: Add a cell to select TX or RX

[Bryan O'Donoghue <bryan.odonoghue@linaro.org>]

On 16/10/2026 09:56, 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 two consumers can use them at the
> same time. 

Two consumers use them - which them ? Two consumers use the receivers at 
the same time ?

Its minor but instead of "them" define what the them is.

The single cell of this binding selects the mode and refers
> to the transmitter, so the receiver cannot be described.
> 
> Allow a second cell that selects the transmitter or the receiver. With
> D-PHY:
> 
> 	/* the MIPI DSI host, driving the transmitter */
> 	phys = <&mipidcphy0 PHY_TYPE_DPHY PHY_DIRECTION_TX>;
> 
> 	/* the MIPI CSI-2 host, driving the receiver */
> 	phys = <&mipidcphy0 PHY_TYPE_DPHY PHY_DIRECTION_RX>;
> 
> and with C-PHY:
> 
> 	phys = <&mipidcphy0 PHY_TYPE_CPHY PHY_DIRECTION_TX>;
> 	phys = <&mipidcphy0 PHY_TYPE_CPHY PHY_DIRECTION_RX>;
> 
> The transmitter and the receiver cannot operate in different modes [1],
> so the first cell must match in both consumers.
> 
> Two cells describe the receiver as well. A single cell keeps referring
> to the transmitter, so existing device trees are unaffected.
> 
> [1] RK3588 TRM: section 22.1 (overview): "The TX and RX only support
>      operate in the same PHY mode."
> 
> Signed-off-by: Jason Yang <jason98166@gmail.com>
> ---
>   .../bindings/phy/rockchip,rk3588-mipi-dcphy.yaml     | 20 +++++++++++++++++---
>   1 file changed, 17 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..6e8cc56e4986 100644
> --- a/Documentation/devicetree/bindings/phy/rockchip,rk3588-mipi-dcphy.yaml
> +++ b/Documentation/devicetree/bindings/phy/rockchip,rk3588-mipi-dcphy.yaml
> @@ -20,11 +20,25 @@ properties:
>       maxItems: 1
>   
>     "#phy-cells":
> -    const: 1
> +    enum: [1, 2]
>       description: |
> -      Argument is mode to operate in. Supported modes are:
> +      The first cell selects the mode to operate in:
>           - PHY_TYPE_DPHY
>           - PHY_TYPE_CPHY
> +
> +      A single cell refers to the transmitter and is kept for existing
> +      device trees.
> +
> +      The second cell selects the transmitter or the receiver, so that a

The second cell, if present

-> you want to make clear it is optional.

> +      MIPI DSI host and a MIPI CSI-2 host can be described as independent
> +      consumers of the same PHY node:
> +        - PHY_DIRECTION_TX
> +        - PHY_DIRECTION_RX
> +
> +      The transmitter and the receiver cannot operate in different modes,
> +      so when both are described, the first cell must match in both
> +      consumers.
> +

Not really related to this patch but how do you envision that 
requirement being enforced, per driver ?
>         See include/dt-bindings/phy/phy.h for constants.
>   
>     clocks:
> @@ -82,6 +96,6 @@ examples:
>                    <&cru SRST_S_MIPI_DCPHY0>;
>           reset-names = "m_phy", "apb", "grf", "s_phy";
>           rockchip,grf = <&mipidcphy0_grf>;
> -        #phy-cells = <1>;
> +        #phy-cells = <2>;
>         };
>       };
> 

Looks pretty good to me I'm interested in adding an RB here - please 
include me in CC for next versions so I may do so.

---
bod