A couple of accelerometers are used to detect the hinge angle in convertible laptops(one for display, one for base/keyboard).

A discussion on the topic is available at [1]

But in my case while DSDT describes two I2C devices (if I interpret it right):

>Device (ACMG)
>        {
>            Name (_ADR, Zero)  // _ADR: Address
>            Name (_HID, "MXC6655")  // _HID: Hardware ID
>            Name (_CID, "MXC6655")  // _CID: Compatible ID
>            Name (_DDN, "Accelerometer with Angle Calculation")  // _DDN: DOS
>            Device Name
>            Name (_UID, One)  // _UID: Unique ID
>            Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource
>            Settings
>            {
>                Name (RBUF, ResourceTemplate ()
>                {
>                    I2cSerialBusV2 (0x0015, ControllerInitiated, 0x00061A80,
>                        AddressingMode7Bit, "\\_SB.PC00.I2C1",
>                        0x00, ResourceConsumer, , Exclusive,
>                        )
>                    I2cSerialBusV2 (0x0015, ControllerInitiated, 0x00061A80,
>                        AddressingMode7Bit, "\\_SB.PC00.I2C2",
>                        0x00, ResourceConsumer, , Exclusive,
>                        )
>                })
>                Return (RBUF) /* \_SB_.PC00.I2C1.ACMG._CRS.RBUF */
>            }

only one of them is detected (display side one, up and running, by the way):

> P: /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-16/i2c-MXC6655:00
> L: 0
> E:
> DEVPATH=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-16/i2c-MXC6655:00
> E: SUBSYSTEM=i2c
> E: DRIVER=mxc4005
> E: MODALIAS=acpi:MXC6655:MXC6655:
>
> P:
> /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-16/i2c-MXC6655:00/iio:device0
> N: iio:device0
> L: 0
> E:
> DEVPATH=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-16/i2c-MXC6655:00/iio:device0
> E: SUBSYSTEM=iio
> E: DEVNAME=/dev/iio:device0
> E: DEVTYPE=iio_device
> E: MAJOR=238
> E: MINOR=0
> E: USEC_INITIALIZED=4954716
> E: IIO_SENSOR_PROXY_TYPE=iio-poll-accel iio-buffer-accel
> E: SYSTEMD_WANTS=iio-sensor-proxy.service
> E: TAGS=:systemd:
> E: CURRENT_TAGS=:systemd:

There should be 2 I2C devices with DRIVER=mxc4005, shouldn't they?

Attaching detailed logs also.

[1] https://gitlab.freedesktop.org/hadess/iio-sensor-proxy/-/merge_requests/338