Re: [PATCH v2] net: fec: add post PHY reset delay DT property

From: Rob Herring
Date: Wed May 31 2017 - 12:44:36 EST


On Tue, May 23, 2017 at 11:48:08AM +0200, Quentin Schulz wrote:
> Some PHY require to wait for a bit after the reset GPIO has been
> toggled. This adds support for the DT property `phy-reset-post-delay`
> which gives the delay in milliseconds to wait after reset.
>
> If the DT property is not given, no delay is observed. Post reset delay
> greater than 1000ms are invalid.
>
> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
> ---
>
> v2:
> - return -EINVAL when phy-reset-post-delay is greater than 1000ms
> instead of defaulting to 1ms,
> - remove `default to 1ms` when phy-reset-post-delay > 1000Ms from DT
> binding doc and commit log,
> - move phy-reset-post-delay property reading before
> devm_gpio_request_one(),
>
> Documentation/devicetree/bindings/net/fsl-fec.txt | 4 ++++
> drivers/net/ethernet/freescale/fec_main.c | 16 +++++++++++++++-
> 2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/net/fsl-fec.txt b/Documentation/devicetree/bindings/net/fsl-fec.txt
> index a1e3693cca16..6f55bdd52f8a 100644
> --- a/Documentation/devicetree/bindings/net/fsl-fec.txt
> +++ b/Documentation/devicetree/bindings/net/fsl-fec.txt
> @@ -15,6 +15,10 @@ Optional properties:
> - phy-reset-active-high : If present then the reset sequence using the GPIO
> specified in the "phy-reset-gpios" property is reversed (H=reset state,
> L=operation state).
> +- phy-reset-post-delay : Post reset delay in milliseconds. If present then

This needs unit suffix minimally. It should also have a vendor prefix or
be made generic.

But really, this is a property of the phy and should be in the phy node
as should phy-reset-gpios, phy-reset-active-high, phy-supply, etc.

> + a delay of phy-reset-post-delay milliseconds will be observed after the
> + phy-reset-gpios has been toggled. Can be omitted thus no delay is
> + observed. Delay is in range of 1ms to 1000ms. Other delays are invalid.
> - phy-supply : regulator that powers the Ethernet PHY.
> - phy-handle : phandle to the PHY device connected to this device.
> - fixed-link : Assume a fixed link. See fixed-link.txt in the same directory.