Re: [PATCH net-next] dt-bindings: mdio: Clarify binding document

From: Roger Quadros
Date: Wed Apr 26 2017 - 09:11:06 EST


On 25/04/17 21:33, Florian Fainelli wrote:
> The described GPIO reset property is applicable to *all* child PHYs. If
> we have one reset line per PHY present on the MDIO bus, these
> automatically become properties of the child PHY nodes.
>
> Finally, indicate how the RESET pulse width must be defined, which is
> the maximum value of all individual PHYs RESET pulse widths determined
> by reading their datasheets.
>
> Fixes: 69226896ad63 ("mdio_bus: Issue GPIO RESET to PHYs.")
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>

Reviewed-by: Roger Quadros <rogerq@xxxxxx>

> ---

> Documentation/devicetree/bindings/net/mdio.txt | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/mdio.txt b/Documentation/devicetree/bindings/net/mdio.txt
> index 4ffbbacebda1..96a53f89aa6e 100644
> --- a/Documentation/devicetree/bindings/net/mdio.txt
> +++ b/Documentation/devicetree/bindings/net/mdio.txt
> @@ -3,13 +3,17 @@ Common MDIO bus properties.
> These are generic properties that can apply to any MDIO bus.
>
> Optional properties:
> -- reset-gpios: List of one or more GPIOs that control the RESET lines
> - of the PHYs on that MDIO bus.
> -- reset-delay-us: RESET pulse width in microseconds as per PHY datasheet.
> +- reset-gpios: One GPIO that control the RESET lines of all PHYs on that MDIO
> + bus.
> +- reset-delay-us: RESET pulse width in microseconds.
>
> A list of child nodes, one per device on the bus is expected. These
> should follow the generic phy.txt, or a device specific binding document.
>
> +The 'reset-delay-us' indicates the RESET signal pulse width in microseconds and
> +applies to all PHY devices. It must therefore be appropriately determined based
> +on all PHY requirements (maximum value of all per-PHY RESET pulse widths).
> +
> Example :
> This example shows these optional properties, plus other properties
> required for the TI Davinci MDIO driver.
> @@ -21,7 +25,7 @@ required for the TI Davinci MDIO driver.
> #size-cells = <0>;
>
> reset-gpios = <&gpio2 5 GPIO_ACTIVE_LOW>;
> - reset-delay-us = <2>; /* PHY datasheet states 1us min */
> + reset-delay-us = <2>;
>
> ethphy0: ethernet-phy@1 {
> reg = <1>;
>

--
cheers,
-roger