Re: [PATCH] net/smsc911x: add device tree probe support

[Shawn Guo <shawn.guo@freescale.com>]

On Fri, Jul 29, 2011 at 09:47:23AM -0600, Grant Likely wrote:
> On Fri, Jul 29, 2011 at 10:36:26AM +0800, Shawn Guo wrote:
> > On Mon, Jul 25, 2011 at 10:28:05PM -0400, Nicolas Pitre wrote:
> > > On Tue, 26 Jul 2011, Shawn Guo wrote:
> > > 
> > > > On Mon, Jul 25, 2011 at 09:16:40PM -0400, Nicolas Pitre wrote:
> > > > > On Tue, 26 Jul 2011, Shawn Guo wrote:
> > > > > 
> > > > > > On Mon, Jul 25, 2011 at 03:37:23PM -0600, Grant Likely wrote:
> > > > > > > On Mon, Jul 25, 2011 at 05:44:00PM +0800, Shawn Guo wrote:
> > > > > > > > It adds device tree probe support for smsc911x driver.
> > > > > > > > 
> > > > > > > > Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> > > > > > > > Cc: Grant Likely <grant.likely@secretlab.ca>
> > > > > > > > Cc: Steve Glendinning <steve.glendinning@smsc.com>
> > > > > > > > Cc: David S. Miller <davem@davemloft.net>
> > > > > > > > ---
> > > > > > > >  Documentation/devicetree/bindings/net/smsc.txt |   34 +++++++
> > > > > > > >  drivers/net/smsc911x.c                         |  123 +++++++++++++++++++-----
> > > > > > > >  2 files changed, 132 insertions(+), 25 deletions(-)
> > > > > > > >  create mode 100644 Documentation/devicetree/bindings/net/smsc.txt
> > > > > > > > 
> > > > > > > > diff --git a/Documentation/devicetree/bindings/net/smsc.txt b/Documentation/devicetree/bindings/net/smsc.txt
> > > > > > > > new file mode 100644
> > > > > > > > index 0000000..1920695
> > > > > > > > --- /dev/null
> > > > > > > > +++ b/Documentation/devicetree/bindings/net/smsc.txt
> > > > > > > > @@ -0,0 +1,34 @@
> > > > > > > > +* Smart Mixed-Signal Connectivity (SMSC) LAN Controller
> > > > > > > > +
> > > > > > > > +Required properties:
> > > > > > > > +- compatible : Should be "smsc,lan<model>""smsc,lan"
> > > > > > > 
> > > > > > > Drop "smsc,lan".  That's far too generic.
> > > > > > > 
> > > > > > The following devices are supported by the driver.
> > > > > > 
> > > > > > LAN9115, LAN9116, LAN9117, LAN9118
> > > > > > LAN9215, LAN9216, LAN9217, LAN9218
> > > > > > LAN9210, LAN9211
> > > > > > LAN9220, LAN9221
> > > > > > 
> > > > > > If we only keep specific <model> as the compatible, we will have a
> > > > > > long match table which is actually used nowhere to distinguish the
> > > > > > device.
> > > > > > 
> > > > > > So we need some level generic compatible to save the meaningless
> > > > > > long match table.  What about: 
> > > > > > 
> > > > > > static const struct of_device_id smsc_dt_ids[] = {
> > > > > >         { .compatible = "smsc,lan9", },
> > > > > >         { /* sentinel */ }
> > > > > > };
> > > > > > 
> > > > > > Or:
> > > > > > 
> > > > > > static const struct of_device_id smsc_dt_ids[] = {
> > > > > >         { .compatible = "smsc,lan91", },
> > > > > >         { .compatible = "smsc,lan92", },
> > > > > >         { /* sentinel */ }
> > > > > > };
> > > > > 
> > > > > None of this unambiguously distinguish the devices supported by this 
> > > > > driver and the smc91x driver which supports LAN91C92, LAN91C94, 
> > > > > LAN91C95, LAN91C96, LAN91C100, LAN91C110.
> > > > > 
> > > > So you suggest to make a long list to explicitly tell the device type
> > > > that the driver supports?
> > > 
> > > I'm not suggesting anything.  :-)  I'm merely pointing out that the 
> > > above .compatible = "smsc,lan9" or .compatible = "smsc,lan91" are too 
> > > generic given that there is another driver with different devices to 
> > > which they could also apply.
> > > 
> > Since I do not get any suggestion here, I'm going to follow the driver
> > name to use '911' as the model number.  Please tell me if there is any
> > better one.
> 
> What is the manufacturer part name?  lan9111 or lan91c11?  The
> manufacturer's documented part number is almost always preferred.
> 
I just posted the v2 of the patch, and chose to use 'smsc,lan9115'
which is the first model supported in the driver.  This is the same
approach I used with i.mx device bindings.

-- 
Regards,
Shawn