iio: accel: kxsd9: Deploy system and runtime PM

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>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/iio/accel/kxsd9-i2c.c b/drivers/iio/accel/kxsd9-i2c.c
index 4aaa27d0aa32..95e20855d2ef 100644
--- a/drivers/iio/accel/kxsd9-i2c.c
+++ b/drivers/iio/accel/kxsd9-i2c.c
@@ -55,6 +55,7 @@ static struct i2c_driver kxsd9_i2c_driver = {
 	.driver = {
 		.name	= "kxsd9",
 		.of_match_table = of_match_ptr(kxsd9_of_match),
+		.pm = &kxsd9_dev_pm_ops,
 	},
 	.probe		= kxsd9_i2c_probe,
 	.remove		= kxsd9_i2c_remove,