feat: support for CRT (Component Retrimming) calibration on BMI270

[maxmclau]

Is your enhancement proposal related to a problem? Please describe.
We manufacture a few boards with BMI270 IMUs and always end up with with major gyroscope trim problems. The BMI270 supports CRT retrimming to "zero out" the gyroscope when it's at rest - saving this calibration offset to flash.

Describe the solution you'd like
We'd like to see an extension of the BMI270 driver with support for SENSOR_ATTR_CALIBRATION (or similar attribute) that completes a CRT calibration procedure. Bosch provides documentation on how this is done in their datasheet (4.14.2 Gyroscope) as well as a sample implementation in their BMI270-Sensor-API.

[nordicjm]

We're offering a $400 bounty for anyone who merges a PR with this functionality

@nashif @kartben this doesn't seem acceptable to be posted here?

[henrikbrixandersen]

The problem with a bounty posted here like this is that even if someone steps up and attempts to solve this issue, there is no guarantee that the resulting patch will be accepted into upstream Zephyr.

[maxmclau]

The problem with a bounty posted here like this is that even if someone steps up and attempts to solve this issue, there is no guarantee that the resulting patch will be accepted into upstream Zephyr.

@abebeos is right - this is standard for bounties. That being said, we would be willing to offer half of the bounty up for a initial functional PR and the other half after merge if that helps. We've been successful with that sponsorship arrangement in the past for other Zephyr contributors.

Up to you guys though. I'll close the issue if Zephyr would rather not encourage bounties.

[carlescufi]

Since there seems to be some controversy regarding the bounty I've added the TSC label.
In the meantime, @maxmclau just a reminder that we also have a #job-postings channel in our Discord that you can use to find a contractor who would do this work for you.

[maxmclau]

Since there seems to be some controversy regarding the bounty I've added the TSC label. In the meantime, @maxmclau just a reminder that we also have a #job-postings channel in our Discord that you can use to find a contractor who would do this work for you.

Thanks for the suggestion - I'll hop over and post it now