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From: Ben Walsh <ben@jubnut.com>
To: Tzung-Bi Shih <tzungbi@kernel.org>
Cc: Benson Leung <bleung@chromium.org>, Guenter Roeck <groeck@chromium.org>,
 "Dustin L. Howett" <dustin@howett.net>, Kieran Levin <ktl@frame.work>,
 Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <linux@weissschuh.net>, Mario Limonciello
 <mario.limonciello@amd.com>, chrome-platform@lists.linux.dev,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/6] platform/chrome: cros_ec_lpc: Correct ACPI name for
 Framework Laptop
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References: <20240515055631.5775-1-ben@jubnut.com>
 <20240515055631.5775-6-ben@jubnut.com> <ZkscFnmHeWWma7Nb@google.com>
 <87jzjk1ibr.fsf@jubnut.com> <Zk_63rrDJFhN1Y1q@google.com>
 <87cypb12j9.fsf@jubnut.com> <ZlKPwlF86Oe8OPK9@google.com>
Date: Mon, 27 May 2024 19:06:40 +0100
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Tzung-Bi Shih <tzungbi@kernel.org> writes:

> On Fri, May 24, 2024 at 07:35:22PM +0100, Ben Walsh wrote:

>> I could add a new quirk which provides an alternative ACPI match table
>> to be used instead of the default. In the default case the match_table
>> will contain only "GOOG0004" as before. But in the Framework EC case the
>> match table will be "PNP0C09".
>
> I think it doesn't work as the current quirk is handling in
> cros_ec_lpc_probe() which is after matching.

I was thinking of a new quirk called CROS_EC_LPC_QUIRK_ACPI_MATCH, and
putting it in cros_ec_lpc_init(), not cros_ec_lpc_probe(). Do we have to
do all quirk handling in cros_ec_lpc_probe()?

> My original idea: would it be possible to get the `adev` in cros_ec_lpc_probe()
> via any lookup API?  If yes, it could still use DMI match and get `adev` if
> required.

That works; I've tested it.

In this scenario we're not using the existing PNP0C09 platform device,
which means I can't look at
/sys/bus/acpi/devices/PNP0C09\:00/physical_node/driver and see the
driver. Is this OK?

(Note that ACPI_COMPANION_SET() doesn't fix this. You can use
acpi_bind_one() but that seems more like internal plumbing).