From: Maximilian Luz <luzmaximilian@gmail.com>
To: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Wang Hongcheng <annie.wang@amd.com>, Ken Xue <Ken.Xue@amd.com>
Subject: Support for AMDI0022 UART
Date: Fri, 23 Apr 2021 21:57:07 +0200 [thread overview]
Message-ID: <295686a0-240d-71d1-a6a0-f3752cf24477@gmail.com> (raw)
Hi all,
I received a report from a Surface Laptop 4 which has a UART that is
identified as AMDI0022 in ACPI [1] and that does not seem to be
supported by the kernel yet.
From what I can tell via ACPI, this is similar to the AMDI0020 [2] UART
that's already supported by the kernel (well, both are devices with two
MMIO regions and an interrupt as far as I can tell...). So it's possible
that all that's needed is adding it to the respective device ID lists
[3, 4]. Unfortunately, I a) don't have a device to test this myself, b)
haven't found any more details on that online, and c) don't want to tell
others to test this without knowing a bit more about that (potentially
writing random stuff to some unknown MMIO region that I don't know
anything about doesn't sound as safe to me as I'd like).
Does anyone here have some pointers on what it'd take to support this,
or any contacts at AMD that could provide more insight?
Regards
Max
[1]: AMDI0022 in ACPI (Surface Laptop 4)
https://github.com/linux-surface/acpidumps/blob/2e24c80d4c7a99a9295aa0b1b2e5e92df93378b4/surface_laptop_4_amd/dsdt.dsl#L1432
[2]: AMDI0020 in ACPI (Surface Laptop 3)
https://github.com/linux-surface/acpidumps/blob/62972f0d806cef45ca01341e3cfbabc04c6dd583/surface_laptop_3_15/dsdt.dsl#L1806
[3]: ID list for 8250_dw
https://elixir.bootlin.com/linux/v5.12-rc8/source/drivers/tty/serial/8250/8250_dw.c#L715
[4]: ID list for acpi_apd
https://elixir.bootlin.com/linux/v5.12-rc8/source/drivers/acpi/acpi_apd.c#L228
next reply other threads:[~2021-04-23 19:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 19:57 Maximilian Luz [this message]
2021-04-24 10:25 ` Support for AMDI0022 UART Andy Shevchenko
2021-04-30 12:37 ` Maximilian Luz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=295686a0-240d-71d1-a6a0-f3752cf24477@gmail.com \
--to=luzmaximilian@gmail.com \
--cc=Ken.Xue@amd.com \
--cc=andriy.shevchenko@linux.intel.com \
--cc=annie.wang@amd.com \
--cc=gregkh@linuxfoundation.org \
--cc=jirislaby@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).