On Thu, Apr 30, 2009 at 9:04 AM, Kyle Moffett <k...@moffetthome.net> wrote: > On Wed, Apr 22, 2009 at 4:21 AM, Benjamin Herrenschmidt > <b...@kernel.crashing.org> wrote: >> On Mon, 2009-04-20 at 20:10 -0400, Kyle Moffett wrote: >>> > IIRC, Ben had some issues with how phylib and the EMAC would need to >>> > interact. Not sure if he has those written down somewhere or not. >>> > (CC'd). >>> >>> Hmm, yeah, I'd be interested to see those. There's enough similar >>> between phylib and the EMAC and sungem drivers that I'm considering a >>> series of somewhat-mechanical patches to make EMAC and sungem use the >>> "struct phy_device" and "struct mii_bus" from phylib, possibly >>> abstracting out some helper functions along the way. >> >> Yup, emac and sungem predate phylib. >> >> I had a quick look at what it would take to port at least emac over, the >> main issue was that I want to be able to sleep (ie, take a mutex) in my >> mdio read/write functions, and back then, phylib wouldn't let me do that >> due to spinlock and timer/softirq usage. > > Ok, I've made some progress in the port, but right now I'm trying to > puzzle out what the "gpcs" bits in the code are. From the few > publicly available docs and some mailing list posts, the gpcs address > appears to be some kind of integrated virtual PHY used when 460GT-ish > chips are communicating via an SGMII bus. My current plan of action > is to separate the "gpcs" out into a separate PHY device controlled by > the emac code. > > I'm also curious about the intent of the "mdio_instance" pointer (IE: > the "mdio-device" property). Is that used when all the PHY devices > are attached to the MDIO bus of only one of the (multiple) emac > devices? Or is that for when two emac chipsets are connected to the > same MDIO bus wire? (or both?) What keeps the emac_instance pointed > to by the "mdio_instance" from going away while the other emac chipset > is using it? > > In either case, I plan to have the device actually holding the MDIO > bus run the mdiobus_alloc() and mdiobus_register() functions, then the > other emac instance will simply take a reference to that MDIO bus > (which would also pin down the emac instance that owns it).
Just a heads up Kyle; there are changes queued in the netdev tree which add OF helpers for MDIO bus drivers and MAC drivers. See here: http://git.kernel.org/?p=linux/kernel/git/davem/net-next-2.6.git;a=commit;h=8bc487d150b939e69830c39322df4ee486efe381 and here is an example of a driver change: http://git.kernel.org/?p=linux/kernel/git/davem/net-next-2.6.git;a=commit;h=1dd2d06c0459a2f1bffc56765e3cc57427818867 Cheers, g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
