[U-Boot] [PATCH V2 4/5] net: fec: sharing MDIO for two enet controllers

[Peng Fan]

> -----Original Message-----
> From: Jagan Teki [mailto:jagannadh.teki at gmail.com]
> Sent: 2018年3月22日 3:00
> To: Joe Hershberger <joe.hershberger at ni.com>
> Cc: Peng Fan <peng.fan at nxp.com>; Fabio Estevam <fabio.estevam at nxp.com>;
> U-Boot Mailing List <u-boot at lists.denx.de>
> Subject: Re: [U-Boot] [PATCH V2 4/5] net: fec: sharing MDIO for two enet
> controllers
> 
> On Thu, Mar 22, 2018 at 12:09 AM, Joe Hershberger <joe.hershberger at ni.com>
> wrote:
> > On Wed, Mar 21, 2018 at 1:29 PM, Jagan Teki <jagannadh.teki at gmail.com>
> wrote:
> >> On Wed, Mar 21, 2018 at 6:54 PM, Peng Fan <peng.fan at nxp.com> wrote:
> >>>> >> >
> >>>> >> >
> >>>> >> >> -----Original Message-----
> >>>> >> >> From: Jagan Teki [mailto:jagannadh.teki at gmail.com]
> >>>> >> >> Sent: 2018年3月21日 17:19
> >>>> >> >> To: Peng Fan <peng.fan at nxp.com>
> >>>> >> >> Cc: Joe Hershberger <joe.hershberger at ni.com>; Fabio Estevam
> >>>> >> >> <fabio.estevam at nxp.com>; U-Boot Mailing List
> >>>> >> >> <u-boot at lists.denx.de>
> >>>> >> >> Subject: Re: [U-Boot] [PATCH V2 4/5] net: fec: sharing MDIO
> >>>> >> >> for two enet controllers
> >>>> >> >>
> >>>> >> >> On Wed, Mar 21, 2018 at 2:31 PM, Peng Fan <peng.fan at nxp.com>
> >>>> wrote:
> >>>> >> >> > On i.MX6SX, 6UL and 7D, there are two enet controllers each
> >>>> >> >> > has a MDIO port. But Some boards share one MDIO port for the
> two enets.
> >>>> >> >> > So introduce a configuration CONFIG_FEC_MXC_MDIO_BASE to
> >>>> >> >> > indicate the MDIO port for sharing.
> >>>> >> >> >
> >>>> >> >> > To i.MX28, adapt to use the new config
> >>>> >> >> >
> >>>> >> >> > Signed-off-by: Peng Fan <peng.fan at nxp.com>
> >>>> >> >> > Acked-by: Joe Hershberger <joe.hershberger at ni.com>
> >>>> >> >> > Cc: Fabio Estevam <fabio.estevam at nxp.com>
> >>>> >> >> > ---
> >>>> >> >> >
> >>>> >> >> > V2:
> >>>> >> >> >  adapt mx28 to use FEC_MXC_MDIO_BASE
> >>>> >> >> >
> >>>> >> >> >  drivers/net/Kconfig       | 9 ++++++++-
> >>>> >> >> >  drivers/net/fec_mxc.c     | 8 ++++++--
> >>>> >> >> >  include/configs/mx28evk.h | 1 +
> >>>> >> >> >  3 files changed, 15 insertions(+), 3 deletions(-)
> >>>> >> >> >
> >>>> >> >> > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> >>>> >> >> > index de1947ccc1..c5fd6f648a 100644
> >>>> >> >> > --- a/drivers/net/Kconfig
> >>>> >> >> > +++ b/drivers/net/Kconfig
> >>>> >> >> > @@ -147,9 +147,16 @@ config ETHOC
> >>>> >> >> >         help
> >>>> >> >> >           This MAC is present in OpenRISC and Xtensa XTFPGA
> >>>> boards.
> >>>> >> >> >
> >>>> >> >> > +config FEC_MXC_MDIO_BASE
> >>>> >> >> > +       hex "MDIO base address for the FEC controller"
> >>>> >> >> > +       depends on FEC_MXC
> >>>> >> >> > +       help
> >>>> >> >> > +         This specifies the MDIO registers base address.
> >>>> >> >> > +It is used
> >>>> when
> >>>> >> >> > +         two FEC controllers share MDIO bus.
> >>>> >> >>
> >>>> >> >> How about retrieving this from dt? we have board that support
> >>>> >> >> dt along with dm supporting.
> >>>> >> >
> >>>> >> > It's ok to retrieve the info from dt, but we are not only
> >>>> >> > support dt, we also need to support non-dt case. Define
> >>>> >> > FEC_MXC_MDIO_BASE is the simplest method to achieve that I think.
> >>>> >>
> >>>> >> But patch adds the same for DM case which usually retrieve the
> >>>> >> info from dt, point here is to get rid of ifdef and new CONFIG_
> >>>> >> ie where DM and dts play smart atleast.
> >>>> >
> >>>> > The uboot fec_mxc driver or net driver is not that sync with
> >>>> > linux code, Using dt here, need to parse phy-handle =
> >>>> > <&ethphy0>;, then parse ethphy0 parent to get reg, I just think this like
> hack.
> >>>>
> >>>> No, I think we can do this with adding new DM MDIO similar to DM
> >>>> PHY which recently done. May be some sort of efforts but it is permanent.
> >>> We do not have that driver now, so could we first have this patch?
> >>> When DM MDIO ready, this piece code could be removed then?
> >>
> >> ie. up to Joe. Honestly this macro become removed in future, my point
> >> here is why we need to maintain dead macro instead of adding proper
> >> maintainable stuff. I'm pretty sure adding DM_MDIO is straight
> >> forward and as of now just add what we need and rest will implement future.
> >> You may become victim to others to move DM_ETH as soon as possible :)
> >
> > It would be ideal if you wanted to implement DM MDIO, but I can also
> > appreciate that this is not already there for you to use. As I
> > commented when I acked this, the I'm OK with this approach at this
> > time due to the state of the DM support in eth.
> 
> As I said before, its your decision.
> 
> >
> > As a side note, maybe moving other boards that use this NIC to DM_ETH
> > and removing non-DM support would be a better cleanup to start with.
> 
> To be honest this can't be predictable (until you make a note on MIGRATION
> deadline), I still see new boards from i.MX still can't use dt.
For NXP vendor boards, Most boards already migrated to use dt, except the 6sabresd
Or 6sabreauto which use SPL + non-DM U-boot. This will be moved to use
SPL + u-boot FIT DM, but sometimes I bother with nand/spinor/norflash spl + fit uboot.

Thanks,
Peng.