Add a timestamping mechanism for buffer that provides accurate
event timestamps when using watermark. This mechanism estimates
device internal clock by comparing FIFO interrupts delta time and
device elapsed time computed by parsing FIFO data.
Take interrupt timestamp in hard irq handler and add IIO device
specific timestamp structures in device private allocation.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add all FIFO parsing and reading functions. Add accel and gyro
kfifo buffer and FIFO data parsing. Use device interrupt for
reading data FIFO and launching accel and gyro parsing.
Support hwfifo watermark by multiplexing gyro and accel settings.
Support hwfifo flush.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>