Re: [PATCH 1/4] serial: meson: add Amlogic S4 UART support

Lucas Tanure <[email protected]>
Newsgroups gmane.comp.boot-loaders.u-boot
Message-ID <d2de2aa9-328b-4779-a6a2-bf2f54cca441__11139.3931716279$1786990687$gmane$org@linux.com>
On 16/08/2026 18:41, Ferass El Hafidi wrote:
> (didn't mean for this to be off-list sorry about that)
> 
> On Sun, 16 Aug 2026 10:42, Lucas Tanure <[email protected] mailto:tanure@l=
> inux.com > wrote:
>> On 10/08/2026 15:01, Ferass El Hafidi wrote:
>>> On Thu, 06 Aug 2026 10:18, "Lucas Tanure via groups.io"=C2=A0
>>> <[email protected] mailto:[email protected] > wrote:
>>>> The S4-generation UART (S4, T7, ...) derives its baud rate from the
>>>> 24 MHz crystal divided by 2, selected via the XTAL_DIV2 bit in the
>>>> baud rate register, while older SoCs divide the crystal by 3. Add the
>>>> "amlogic,meson-s4-uart" compatible with driver data selecting the
>>>> div-by-2 scheme, matching the Linux driver (meson_s4_uart_data) and
>>>> the configuration the vendor BL2 programs on T7 hardware.
>>>>
>>>> Older SoCs keep the existing div-by-3 behaviour: Linux also uses
>>>> div-by-2 on G12A, but both modes work there and switching would risk
>>>> regressing boards that have shipped with div-by-3 for years.
>>>>
>>>> Also drain the transmitter before changing the baud rate so in-flight
>>>> characters are not garbled, as the Linux driver does.
>>>>
>>>> Assisted-by: Claude:claude-fable-5
>>> =C2=A0
>>> As I understand it, LLM-assisted patches are not welcome in U-Boot rig=
> ht
>>> now: https://lore.kernel.org/u-boot/20260515220758.GM1858239@bill-the-=
> cat/
>>> =C2=A0
>>> AFAIK there isn't an official AI policy yet, but it seems the concensu=
> s
>>> on that matter is currently "please don't". Sorry.
>>
>> Ok, I will drop this line.
>>
> 
> Please do not drop this line. I appreciate the transparency towards your
> use of AI. I would wait for someone more knowlegable about AI use
> discussions to reply.

Ok, I will reply with v2 with all comments fixes and keeping the Ai 
line. And I wait for the Ai talk.

> Best regards,
> Ferass

Thanks
Lucas
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