Re: [PATCH] iio/hid: Add mount_matrix

[srinivas pandruvada <srinivas.pandruvada@linux.intel.com>]

On Mon, 2022-06-27 at 13:23 -0700, Gwendal Grignou wrote:
> On Mon, Jun 27, 2022 at 2:55 AM Bastien Nocera <hadess@hadess.net>
> wrote:
> > 
> 
[...]

> Relying on a quirk file for all standalone sensors is not sustainable
> IMHO. I agree changing existing output in newer kernels is also very
> difficult.
> Should we add a new iio sysfs attribute to indicate the sensors
> report
> data according to either the W3C specification or HID specification?
> If present, and set to W3C, iio-sensor-proxy would invert the axis
> first before applying [new] rotation matrices which will never change
> the basis.

When we added support for HID sensor hub, it was primarily driven for
supporting Linux on systems sold with Windows. This started from USB
external hubs to i2c external hubs to now ISH. Still they all are
designed for Windows primarily as OEMs will test on Windows and will
have to pass Windows compliance tests.

We can export the following fields to user space to do any model
specific quirks:

From HID spec:

Property: Sensor Manufacturer
Property: Sensor Model
Property: Sensor Serial Number
Property: Sensor Description
Property: Sensor Connection Type
Connection Type: PC Integrated
Connection Type: PC Attached
Connection Type: PC External
Property: Sensor Device Path
Property: Hardware Revision
Property: Firmware Version
Property: Release Date

Thanks,
Srinivas