Re: [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for Allwinner sun8i-emac

From: Maxime Ripard
Date: Thu Jul 28 2016 - 14:49:26 EST


On Thu, Jul 28, 2016 at 03:40:31PM +0200, LABBE Corentin wrote:
> On Thu, Jul 21, 2016 at 09:55:19AM +0200, Maxime Ripard wrote:
> > Hi,
> >
> > On Wed, Jul 20, 2016 at 10:03:18AM +0200, LABBE Corentin wrote:
> > > This patch adds documentation for Device-Tree bindings for the
> > > Allwinner sun8i-emac driver.
> > >
> > > Signed-off-by: LABBE Corentin <clabbe.montjoie@xxxxxxxxx>
> > > ---
> > > .../bindings/net/allwinner,sun8i-emac.txt | 65 ++++++++++++++++++++++
> > > 1 file changed, 65 insertions(+)
> > > create mode 100644 Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > >
> > > diff --git a/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > new file mode 100644
> > > index 0000000..4bf4e53
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/net/allwinner,sun8i-emac.txt
> > > @@ -0,0 +1,65 @@
> > > +* Allwinner sun8i EMAC ethernet controller
> > > +
> > > +Required properties:
> > > +- compatible: "allwinner,sun8i-a83t-emac", "allwinner,sun8i-h3-emac",
> > > + or "allwinner,sun50i-a64-emac"
> > > +- reg: address and length of the register sets for the device.
> > > +- reg-names: should be "emac" and "syscon", matching the register sets
> >
> > Blindly mapping a register of some other device on the SoC doesn't
> > look very reasonable.
>
> As we discuss after this mail on IRC, this register is dedicated to EMAC.

I don't think we did. It's still right in the middle of some other
hardware block register space. You actually have a syscon driver to do
just that, why not use it?

> > > +See ethernet.txt in the same directory for generic bindings for ethernet
> > > +controllers.
> > > +
> > > +The device node referenced by "phy" or "phy-handle" should be a child node
> > > +of this node. See phy.txt for the generic PHY bindings.
> > > +
> > > +Optional properties:
> > > +- phy-supply: phandle to a regulator if the PHY needs one
> > > +- phy-io-supply: phandle to a regulator if the PHY needs a another one for I/O.
> > > + This is sometimes found with RGMII PHYs, which use a second
> > > + regulator for the lower I/O voltage.
> > > +- allwinner,tx-delay: The setting of the TX clock delay chain
> > > +- allwinner,rx-delay: The setting of the RX clock delay chain
> >
> > In which unit? What is the default value?
>
> The unit is unknown to me, but I have added a comment for the
> default and acceptable range value.

That's unfortunate. We'll see how the DT maintainers feel about that.

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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