Re: [PATCH v2] arm64: dts: qcom: x1e80100-dell-xps13-9345: enable onboard accelerometers

[Val Packett]

On 3/31/26 10:36 AM, Aleksandrs Vinarskis wrote:
> Particular laptop comes with two sets of sensors:
> 1. Motherboard: accelerometer
> 2. Display/Camera module: accelerometer, ambient ligth (and more)
>     sensor
>
> Both i2c busses are bound to Snapdragon Sensor Core (SSC) and are
> typically controlled by (A)DSP thus allowing for great power
> efficiency. This however requires DSP libraries matching ADSP firmware,
> sensors descriptions (must be extracted from Windows) and other
> potentially closed-source libraries. Opensource tooling includes
> `libssc` and `hexagonrpcd`, but they were not verified to be working.
>
> Until SSC support for X1E lands, bitbang both i2c busses to enable
> accelerometer functionality. In the future if/when sensors on this
> platform can be used from DSP directly, this commit can be reverted.
>
> [..]

WDYM by "support lands"? It's a userspace setup thing, nothing new 
should be required in the kernel.

It is amazing that this bitbanging works here, I don't think it was 
expected to ever work on anything newer than msm89x7 o.0

But this is likely inefficient… and "stealing" GPIOs from ADSP like this 
sounds rather scary. And would definitely break SSC initialization for 
anyone wanting to bring up hexagonrpcd/iio-sensor-proxy.

~val