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

["Ferass El Hafidi" <funderscore@postmarketos.org>]

(didn't mean for this to be off-list sorry about that)

On Sun, 16 Aug 2026 10:42, Lucas Tanure <tanure@linux.com 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
>> <tanure=3Dlinux.com@groups.io mailto:linux.com@groups.io > 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.

Best regards,
Ferass