Re: [PATCH v5 2/4] Documentation: bindings: add phy_config for Rockchip USB Type-C PHY

From: Heiko Stuebner
Date: Fri May 18 2018 - 11:28:27 EST


Am Donnerstag, 17. Mai 2018, 11:17:58 CEST schrieb Lin Huang:
> If want to do training outside DP Firmware, need phy voltage swing
> and pre_emphasis value.
>
> Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - None
> Changes in v3:
> - modify property description and add this property to Example
> Change in v4:
> - None
> Change in v5:
> - None
>
> .../devicetree/bindings/phy/phy-rockchip-typec.txt | 29 +++++++++++++++++++++-
> 1 file changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/phy/phy-rockchip-typec.txt b/Documentation/devicetree/bindings/phy/phy-rockchip-typec.txt
> index 960da7f..af298f2 100644
> --- a/Documentation/devicetree/bindings/phy/phy-rockchip-typec.txt
> +++ b/Documentation/devicetree/bindings/phy/phy-rockchip-typec.txt
> @@ -17,7 +17,8 @@ Required properties:
>
> Optional properties:
> - extcon : extcon specifier for the Power Delivery
> -
> + - rockchip,phy_config : A list of voltage swing(mv) and pre-emphasis
> + (dB) pairs.

mv -> mV I'd think.

This needs a bit more explanation please. Especially as the multiple "0 0"
lines in the examples suggest some deeper ordering requirements.
Like the 3 blocks of 4 entries as can be seen in the default config in
patch3. The binding should definitly describe what these are.


> Required nodes : a sub-node is required for each port the phy provides.
> The sub-node name is used to identify dp or usb3 port,
> and shall be the following entries:
> @@ -50,6 +51,19 @@ Example:
> <&cru SRST_P_UPHY0_TCPHY>;
> reset-names = "uphy", "uphy-pipe", "uphy-tcphy";
>
> + rockchip,phy_config =<0x2a 0x00
> + 0x1f 0x15
> + 0x14 0x22
> + 0x02 0x2b
> + 0x21 0x00
> + 0x12 0x15
> + 0x02 0x22
> + 0 0
> + 0x15 0x00
> + 0x00 0x15
> + 0 0
> + 0 0>;

I don't think they should be hex-values, as according to the doc above
these are values in mV and dB .


Heiko