[PATCH] DT: add MDIO node for FMan node

[Shaohui Xie]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Thursday, November 13, 2014 2:17 PM
> To: Xie Shaohui-B21989
> Cc: Liberman Igal-B31950; linuxppc-dev at lists.ozlabs.org;
> devicetree at vger.kernel.org; Medve Emilian-EMMEDVE1
> Subject: Re: [PATCH] DT: add MDIO node for FMan node
> 
> 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; linuxppc-dev at lists.ozlabs.org;
> > > devicetree at vger.kernel.org; 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: shh.xie at gmail.com
> > > > > Cc: linuxppc-dev at lists.ozlabs.org; devicetree at vger.kernel.org;
> > > > > 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, shh.xie at gmail.com wrote:
> > > > > > From: Shaohui Xie <Shaohui.Xie at freescale.com>
> > > > > >
> > > > > > This binding is for FMan MDIO, it covers FMan v2 & FMan v3.
> > > > > >
> > > > > > Signed-off-by: Shaohui Xie <Shaohui.Xie at freescale.com>
> > > > > > ---
> > > > > > 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] The purpose here is to get a specific clock frequency, driver to use it to calculate the divider.
Then the Fman clock can be divided to the frequency.

> > [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?
[S.H] Yes. But it's not used by driver. (I know I should not say this :) )

Thanks.
Shaohui