Re: [PATCH v4] platform: x86: Add ACPI driver for ChromeOS

From: Rafael J. Wysocki
Date: Mon Apr 13 2020 - 16:42:08 EST


On Mon, Apr 13, 2020 at 3:46 PM Enric Balletbo i Serra
<enric.balletbo@xxxxxxxxxxxxx> wrote:
>
> This driver attaches to the ChromeOS ACPI device and then exports the values
> reported by the ACPI in a sysfs directory. These values are not exported
> via the standard ACPI tables, hence a specific driver is needed to do
> it.

So how exactly are they exported?

> The ACPI values are presented in the string form (numbers as decimal
> values) or binary blobs, and can be accessed as the contents of the
> appropriate read only files in the standard ACPI devices sysfs directory tree.

My understanding based on a cursory look at the patch is that there is
an ACPI device with _HID equal to "GGL0001" and one or more special
methods under it that return values which you want to export over
sysfs as binary attributes. They appear to be read-only.

I guess that these data are to be consubed by user space?