[U-Boot-Board-Maintainers] Raspberry pi 4 - u-boot - genet / scb

[Sascha Dewald]

Hi,

could someone give me a summary which is missing in u-boot and what needs
to be ported ?

I found other broadcom drivers, which are already in u-boot.

How difficult is it, to strip the drivers down, from the linux kernel to
work with u-boot?

Kind Regards,
Sascha





Am Mi., 20. Nov. 2019 um 12:21 Uhr schrieb Andre Przywara <
andre.przywara at arm.com>:

> On Wed, 20 Nov 2019 12:13:55 +0100
> Matthias Brugger <mbrugger at suse.com> wrote:
>
> Hi,
>
> > Adding Andre as he helps in the effort to port the driver. More comments
> inline.
> >
> > On 19/11/2019 22:46, Heinrich Schuchardt wrote:
> > > On 11/19/19 9:48 PM, Simon Glass wrote:
> > >> Hi Sascha,
> > >>
> > >> On Tue, 19 Nov 2019 at 10:10, Sascha Dewald <sascha.dewald at gmail.com>
> wrote:
> > >>>
> > >>> Hi Simon,
> > >>>
> > >>> it uses bcmgenet.
> > >>>
> > >>> Below some information from "hwinfo" and "dmesg"
> > >>>
> > >>
> > >> OK, well I think this is in linux as
> drivers/net/ethernet/broadcom/genet
> > >>
> > >> I'm not sure about the PHY but it looks like there is no driver for
> > >> genet in U-Boot. I suggest poriting it over.
>
> Amit (CC:ed) is working on that. That is still quite rough and not really
> working yet, but as of yesterday he saw the first (empty) packets on the
> line at least.
> I would assume we get something working still this year.
>
> > > In linux-next/next-20191119
> > > arch/arm64/boot/dts/broadcom/bcm2711-rpi-4-b.dtb
> > > there is no network device.
> > >
> > Florian send a new pull request, I think yesterday which adds the genet
> driver
> > to RPi4.
>
> I found the burst length quirk together with the new compatible string in
> David's net-next/master two days ago.
>
> > > On Raspbian you can find for RPi4:
> > >
> > > compatible = "brcm,genet-v5"
> > > relating to Linux drivers/net/ethernet/broadcom/genet/bcmgenet.c
> > > CONFIG_BCMGENET "Broadcom GENET internal MAC support"
> > >
> >
> > RPi4 is a special case as DMA burst size is different from plain genet-v5
> > driver. But that might be of no relevance for U-Boot.
>
> Yeah, since there is no other user, we could just go ahead and fix the
> smaller burst length of 8 in U-Boot. I guess we don't care about the
> performance impact that has.
>
> Cheers,
> Andre.
>
> >
> > > compatible = "ethernet-phy-ieee802.3-c22";
> > > relating to Linux drivers/of/of_mdio.c.
> > > CONFIG_OF_MDIO OpenFirmware MDIO bus (Ethernet PHY) accessors
> > >
> > > compatible = "brcm,genet-mdio-v5";
> > > relating to Linux drivers/net/phy/mdio-bcm-unimac.c
> > > CONFIG_MDIO_BCM_UNIMAC "Broadcom UniMAC MDIO bus controller"
> > >
> > > So wouldn't we need all three drivers?
> > >
> > > Maybe Joe can tell us.
> > >
> > > Best regards
> > >
> > > Heinrich
> > >
> > >
> > >>
> > >> Regards,
> > >> Simon
> > >> _______________________________________________
> > >> U-Boot-Board-Maintainers mailing list
> > >> U-Boot-Board-Maintainers at lists.denx.de
> > >> https://lists.denx.de/listinfo/u-boot-board-maintainers
> > >>
> > >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.denx.de/pipermail/u-boot-board-maintainers/attachments/20191121/297dd407/attachment.html>