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

[Heiko Schocher]

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?

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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