[PATCH 1/2] Documentation: phy: introduce new optional property to specify drive impedance

[Rob Herring]

On Thu, Jan 05, 2017 at 05:31:21PM +0800, Shawn Lin wrote:
> We need to modify the drive impedance according to the
> different hardware condition. So let's expose this to
> the DT.
> 
> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
> ---
> 
>  Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> index e3ea557..731aeb9 100644
> --- a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> +++ b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
> @@ -14,6 +14,11 @@ specified by name:
>  		access to it), it is strongly suggested.
>   - clocks: Should have a phandle to the card clock exported by the SDHCI driver.
>  
> +Optional Properties:
> +- drive_impedance: Must be one of 33, 40, 50, 66, 100. This property allows
> +	different boards to specify their own drive impedance depending on the
> +	hardware condition.

Needs a vendor prefix. Don't use '_'. And needs unit suffix (-ohms).

> +
>  Example:
>  
>  
> -- 
> 1.9.1
> 
>