dm, serial: problem with using ns16550 driver before relocation on mpc83xx

[Simon Glass]

Hi Heiko,

On Thu, 6 Feb 2020 at 22:53, Heiko Schocher <hs at denx.de> wrote:
>
> Hi Simon,
>
> removed Dirk from cc and added Mario Six
>
> @Mario: Dirk is maintainer of the gazerbeam board:
>
> https://gitlab.denx.de/u-boot/u-boot/blob/master/board/gdsys/mpc8308/MAINTAINERS#L2
>
> but EMail get not delivered to his EMail address ... so I added
> you to cc ... may you have a gazerbeam board? May you can try,
> if current U-Boot mainline works (in special serial console) on it?

BTW I don't have one of these. I can't even find it on the internet!

Regards,
Simon


>
> thanks!
>
> Am 06.02.2020 um 18:46 schrieb Simon Glass:
> > Hi Heiko,
> >
> > On Wed, 5 Feb 2020 at 22:19, Heiko Schocher <hs at denx.de> wrote:
> >>
> >> Hello Simon,
> >>
> >> Am 05.02.2020 um 18:59 schrieb Simon Glass:
> >>> Hi Heiko,
> >>>
> >>> On Wed, 5 Feb 2020 at 02:04, Heiko Schocher <hs at denx.de> wrote:
> >>>>
> >>>> Hello Bin, Simon,
> >>>>
> >>>> I just porting the mpc83xx based kmcoge5ne board support DTS and got
> >>>> problems using the serial ns16550 driver.
> >>>>
> >>>> I need the serial driver before rolcation, so I enabled
> >>>> "u-boot,dm-pre-reloc;" as usual in the device tree, but board does not
> >>>> boot ...
> >>>>
> >>>> I found the commit:
> >>>>
> >>>> commit 4687919684e0e4390b9fc20d1809ecaa9dc3cb81
> >>>> Author: Bin Meng <bmeng.cn at gmail.com>
> >>>> Date:   Wed Oct 24 06:36:36 2018 -0700
> >>>>
> >>>>        serial: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >>>>
> >>>> which added to the ns16550 serial driver:
> >>>>
> >>>> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> >>>> index 04b604fa2c..1e6fc6c668 100644
> >>>> --- a/drivers/serial/ns16550.c
> >>>> +++ b/drivers/serial/ns16550.c
> >>>> @@ -487,7 +487,9 @@ U_BOOT_DRIVER(ns16550_serial) = {
> >>>>            .priv_auto_alloc_size = sizeof(struct NS16550),
> >>>>            .probe = ns16550_serial_probe,
> >>>>            .ops    = &ns16550_serial_ops,
> >>>> +#if !CONFIG_IS_ENABLED(OF_CONTROL)
> >>>>            .flags  = DM_FLAG_PRE_RELOC,
> >>>> +#endif
> >>>>     };
> >>>>     #endif
> >>>>     #endif /* SERIAL_PRESENT */
> >>>>
> >>>> So, as OF_CONTROL is defined for me, the flag "u-boot,dm-pre-reloc" seems
> >>>> not working anymore ...
> >>>>
> >>>> Adding this back:
> >>>>
> >>>> hs at xmglap:u-boot-secu  [20200205-temp] $ git diff
> >>>> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> >>>> index 9851663dc5..386ca9cffa 100644
> >>>> --- a/drivers/serial/ns16550.c
> >>>> +++ b/drivers/serial/ns16550.c
> >>>> @@ -528,7 +528,7 @@ U_BOOT_DRIVER(ns16550_serial) = {
> >>>>            .priv_auto_alloc_size = sizeof(struct NS16550),
> >>>>            .probe = ns16550_serial_probe,
> >>>>            .ops    = &ns16550_serial_ops,
> >>>> -#if !CONFIG_IS_ENABLED(OF_CONTROL)
> >>>> +#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
> >>>>            .flags  = DM_FLAG_PRE_RELOC,
> >>>>     #endif
> >>>>     };
> >>>>
> >>>> and board boots fine with the flag "u-boot,dm-pre-reloc" in DTS ...
> >>>>
> >>>> May I do something wrong here? I found in mainline for example
> >>>> the "arch/powerpc/dts/gdsys/gazerbeam-uboot.dtsi" board, which
> >>>> has the exactly same dts settings than I have now.
> >>>>
> >>>> @Dirk: Can you check, if this board boots with current mainline?
> >>>>
> >>>> Shouldn;t be the logic, that in case OF_CONTROL is enabled and if
> >>>> flag "u-boot,dm-pre-reloc" is set in DTS for the device, the device
> >>>> should be bound before relocation, and we do not need to check, if
> >>>> the driver sets DM_FLAG_PRE_RELOC ?
> >>>>
> >>>> But may I miss here something ...
> >>>>
> >>>> Any hints?
> >>>
> >>> +Tom Rini
> >>>
> >>> I found I needed this for rpi.
> >>>
> >>> http://patchwork.ozlabs.org/patch/1202913/
> >>>
> >>> But I still haven't gone back to figure out why Tom doesn't.
> >>
> >> Hmm... I have added the "u-boot,dm-pre-reloc;" to the uart node.
> >>
> >> Like it is for the gazerbeam board, see [1]
> >>
> >> It works if "DM_FLAG_PRE_RELOC" is set the driver in flags... no
> >> need for a gpio node before relocation like it is inabove patch.
> >>
> >> I wonder if we need DM_FLAG_PRE_RELOC at all in a driver and
> >> OF_CONTROL case. Shouldn't it be enough if the DTB node for the
> >> driver contains the "u-boot,dm-pre-reloc;" property?
> >
> > Well in the rpi case it is the pinctrl that needs that property. I
> > think you should dig into exactly what is going wrong on the board you
> > have. Then it should be possible to see what is missing and add it.
>
> Ok, I try to find out more, thanks!
>
> bye,
> Heiko
> --
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