Subject: Re: [PATCH] DT: add MDIO node for FMan node

From: Scott Wood <[email-masked]>
Date: Thu, 13 Nov 2014 00:16:39 -0600

On Wed, 2014-11-12 at 07:40 -0600, Xie Shaohui-B21989 wrote:
> > -----Original Message-----
> > From: Wood Scott-B07421
> > Sent: Wednesday, November 12, 2014 1:38 AM
> > To: Xie Shaohui-B21989
> > Cc: Liberman Igal-B31950; [email-masked];
> > [email-masked]; Medve Emilian-EMMEDVE1
> > Subject: Re: [PATCH] DT: add MDIO node for FMan node
> > 
> > On Tue, 2014-11-11 at 04:32 -0600, Xie Shaohui-B21989 wrote:
> > > > -----Original Message-----
> > > > From: Wood Scott-B07421
> > > > Sent: Tuesday, November 11, 2014 8:23 AM
> > > > To: [email-masked]
> > > > Cc: [email-masked]; [email-masked]; Medve
> > > > Emilian-EMMEDVE1; Xie Shaohui-B21989
> > > > Subject: Re: [PATCH] DT: add MDIO node for FMan node
> > > >
> > > > On Tue, 2014-11-04 at 19:56 +0800, [email-masked] wrote:
> > > > > From: Shaohui Xie <[email-masked]>
> > > > >
> > > > > This binding is for FMan MDIO, it covers FMan v2 & FMan v3.
> > > > >
> > > > > Signed-off-by: Shaohui Xie <[email-masked]>
> > > > > ---
> > > > > based on http://patchwork.ozlabs.org/patch/390351/
> > > > > for 'next' of
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux.git
> > > >
> > > > Are there any other FMan pieces that are missing from the above patch?
> > > [S.H] I'm adding Igal for this comment.
> > >
> > > >
> > > > > +- bus-frequency
> > > > > +		Usage: optional
> > > > > +		Value type: <u32>
> > > > > +		Definition: Default MDIO bus clock speed.
> > > >
> > > > Use clocks/clock-names
> > > [S.H] The MDIO uses Fman clock and divides it to a proper value which
> > is specified by this property.
> > 
> > Use clocks/clock-names to describe that relationship.
> > 
>
> [S.H] The MDIO node is sub-node and embedded in Fman node, the
> clocks/clock-names is provided by Fman node, should repeat them in MDIO
> node? For the default MDIO bus clock speed, maybe "clock-ranges" should
> be used?

It's a different clock.  You wouldn't be repeating.  If it's derived
from the FMan clock, then maybe you don't need anything here (does the
driver know what the divider is, or would that need to be specified in
the device tree?), but no more clock-frequency/bus-frequency properties.

> [S.H] since Fman V2 & V3 can be differentiated by compatible, a boolean
> property "fsl,fman-internal-mdio" seems better, if defined, it
> indicates an internal MDIO. It looks like below:
> 
> fsl,fman-internal-mdio
> 		Usage: required for internal MDIO
> 		Value type: Boolean
> 		Definition: Fman has internal MDIO for internal PCS(Physical
> 		Coding Sublayer) PHYs and external MDIO for external PHYs.
> 		The settings and programming routines for internal/external
> 		MDIO are different. Must be included for internal MDIO.
> 
> How about this?

This looks better, thanks.

This would be set on fman v2 TBI mdio nodes as well, right?

-Scott