This deploys runtime and system PM in the KXSD9 driver:
- Use the force_runtime_suspend/resume callbacks as system PM
operations.
- Add buffer prepare/unprepare callbacks to grab the runtime
PM while we're using buffered reads and put get/put_autosuspend
in these.
- Insert get/put_autosuspend calls anywhere the IO is used from
the raw read/write callbacks.
- Move the fullscale setting to be cached in the state container
so we can restore it properly when coming back from
system/runtime suspend.
- Set the autosuspend delay to two orders of magnitude that of
the sensor start-up time (20ms) so we will autosuspend after
2s.
- Register the callbacks in both the SPI and I2C subdrivers.
Tested with the I2C KXSD9 on the Qualcomm APQ8060 Dragonboard.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
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