From mboxrd@z Thu Jan  1 00:00:00 1970
From: Simon Glass <sjg@chromium.org>
Date: Wed, 5 Feb 2020 10:59:11 -0700
Subject: dm, serial: problem with using ns16550 driver before relocation
 on mpc83xx
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References: <e617f766-083b-0cd2-690a-987fad82aaea@denx.de>
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To: u-boot@lists.denx.de

Hi Heiko,

On Wed, 5 Feb 2020 at 02:04, Heiko Schocher <hs@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@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.

Regards,
Simon