iio/pressure/zpa2326.c

18  * ZPA2326 hardware supports 2 sampling mode: one shot and continuous.
20  * A complete one shot sampling cycle gets device out of low power mode,
22  * back to low power mode. It is meant for on demand sampling with optimal power
23  * saving at the cost of lower sampling rate and higher software overhead.
35  * - setup hardware sampling period,
38  * - when no longer needed, stop sampling process by putting device into
44  * Note that hardware sampling frequency is taken into account only when
45  * internal hardware trigger is attached as the highest sampling rate seems to
50  *   differential pressure sampling ;
78  * struct zpa2326_frequency - Hardware sampling frequency descriptor
89  * correspond to the highest sampling frequency.
98 /* Return the highest hardware sampling frequency available. */
110  * @result:     Allows sampling logic to get completion status of operations
112  * @data_ready: Interrupt handler uses this to wake user context up at sampling
118  *              DT, in which case sampling logic keeps polling status register
120  * @frequency:  Current hardware sampling frequency.
213  * Required to access complete register space and to perform any sampling
265  * Disable sampling and empty hardware FIFO.
290  * zpa2326_start_oneshot() - Start a single sampling cycle, i.e. in one shot
292  * @indio_dev: The IIO device associated with the sampling hardware.
321  * @indio_dev: The IIO device associated with the sampling hardware.
324  * Sampling will be disabled, preventing strange things from happening in our
371  * @indio_dev: The IIO device associated with the sampling hardware.
387  * @indio_dev: The IIO device associated with the sampling hardware.
434  * @indio_dev: The IIO device associated with the sampling hardware.
505  * @indio_dev: The IIO device associated with the sampling hardware.
574  * @indio_dev: The IIO device associated with the sampling hardware.
658  * @indio_dev: The IIO device associated with the sampling hardware.
691  * @indio_dev: The IIO device associated with the sampling hardware.
742  * @data: The IIO device associated with the sampling hardware.
754 		/* Timestamping needed for buffered sampling only. */  in zpa2326_handle_irq()
765  * @data: The IIO device associated with the sampling hardware.
772  * When device is using its own internal hardware trigger in continuous sampling
779  * hook. This means one of the latter is currently waiting for sampling
798 	 * currently working in continuous sampling mode ?  in zpa2326_handle_threaded_irq()
857  * @indio_dev: The IIO device associated with the sampling hardware.
931  * @indio_dev: The IIO device associated with the sampling hardware.
933  * Loop over registers content to detect end of sampling cycle. Used when DT
1000  * @indio_dev: The IIO device associated with the sampling hardware.
1051  * zpa2326_sample_oneshot() - Perform a complete one shot sampling cycle.
1052  * @indio_dev: The IIO device associated with the sampling hardware.
1079 		 * Sampling operation always generates both temperature and  in zpa2326_sample_oneshot()
1103 	/* Start a sampling cycle in oneshot mode. */  in zpa2326_sample_oneshot()
1108 	/* Wait for sampling cycle to complete. */  in zpa2326_sample_oneshot()
1129  * zpa2326_trigger_handler() - Perform an IIO buffered sampling round in one
1136  * currently attached. Allows us to synchronize this device buffered sampling
1165 	 * hardware sampling mode.  in zpa2326_trigger_handler()
1170 		/* On demand sampling : start a one shot cycle. */  in zpa2326_trigger_handler()
1174 		/* Wait for sampling cycle to complete. */  in zpa2326_trigger_handler()
1194 		/* Don't switch to low power if sampling continuously. */  in zpa2326_trigger_handler()
1205  *                              sampling
1207  * @indio_dev: The IIO device associated with the sampling hardware.
1229  * zpa2326_postenable_buffer() - Configure device for triggered sampling.
1230  * @indio_dev: The IIO device associated with the sampling hardware.
1233  * Otherwise, let internal trigger configure continuous sampling :
1292  * zpa2326_set_trigger_state() - Start / stop continuous sampling.
1293  * @trig:  The trigger being attached to IIO device associated with the sampling
1297  * Basically enable / disable hardware continuous sampling mode.
1328 		 * Disable continuous sampling mode to restore settings for  in zpa2326_set_trigger_state()
1329 		 * one shot / direct sampling operations.  in zpa2326_set_trigger_state()
1355 		 * Switch trigger on : start continuous sampling at required  in zpa2326_set_trigger_state()
1368 		/* Enable continuous sampling at specified frequency. */  in zpa2326_set_trigger_state()
1390  * @parent:    Hardware sampling device @indio_dev is a child of.
1391  * @indio_dev: The IIO device associated with the sampling hardware.
1450 	/* Don't allow changing frequency if buffered sampling is ongoing. */  in zpa2326_set_frequency()
1462 /* Expose supported hardware sampling frequencies (Hz) through sysfs. */
1599 	/* Setup for userspace synchronous on demand sampling. */  in zpa2326_create_managed_iiodev()
1634 	/* Set default hardware sampling frequency to highest rate supported. */  in zpa2326_probe()