2 /* gain-time-scale conversion helpers for IIO light sensors
22  * iio_gts_get_gain - Convert scale to total gain
24  * Internal helper for converting scale to total gain.
26  * @max:	Maximum linearized scale. As an example, when scale is created
27  *		in magnitude of NANOs and max scale is 64.1 - The linearized
28  *		scale is 64 100 000 000.
29  * @scale:	Linearized scale to compute the gain for.
31  * Return:	(floored) gain corresponding to the scale. -EINVAL if scale
34 static int iio_gts_get_gain(const u64 max, const u64 scale)  in iio_gts_get_gain()  argument
39 	if (scale > full || !scale)  in iio_gts_get_gain()
42 	if (U64_MAX - full < scale) {  in iio_gts_get_gain()
44 		if (full - scale < scale)  in iio_gts_get_gain()
47 		full -= scale;  in iio_gts_get_gain()
51 	while (full > scale * (u64)tmp)  in iio_gts_get_gain()
58  * gain_get_scale_fraction - get the gain or time based on scale and known one
60  * @max:	Maximum linearized scale. As an example, when scale is created
61  *		in magnitude of NANOs and max scale is 64.1 - The linearized
62  *		scale is 64 100 000 000.
63  * @scale:	Linearized scale to compute the gain/time for.
68  * Compute either gain or time based on scale and either the gain or time
73 static int gain_get_scale_fraction(const u64 max, u64 scale, int known,  in gain_get_scale_fraction()  argument
78 	tot_gain = iio_gts_get_gain(max, scale);  in gain_get_scale_fraction()
114 	 * Expect scale to be (mostly) NANO or MICRO. Divide divider instead of  in iio_gts_linearize()
127  * iio_gts_total_gain_to_scale - convert gain to scale
128  * @gts:	Gain time scale descriptor
130  * @scale_int:	Pointer to integral part of the scale (typically val1)
131  * @scale_nano:	Pointer to fractional part of the scale (nano or ppb)
133  * Convert the total gain value to scale. NOTE: This does not separate gain
153  * iio_gts_purge_avail_scale_table - free-up the available scale tables
154  * @gts:	Gain time scale descriptor
274  * @gts:	Gain time scale descriptor
353  * @gts:	Gain time scale descriptor
416  * @gts:	Gain time scale descriptor
431  * @gts:	Gain time scale descriptor
471  * @gts:	Gain time scale descriptor
474  * integration time and scale tables.
490  * @gts:	Gain time scale descriptor
596  * devm_iio_init_iio_gts - Initialize the gain-time-scale helper
599  * @max_scale_int:	integer part of the maximum scale value
600  * @max_scale_nano:	fraction part of the maximum scale value
612  * Initialize the gain-time-scale helper for use. Note, gains, times, selectors
637  * @gts:	Gain time scale descriptor
639  * @type:	Type of returned scale values
660  * @gts:	Gain time scale descriptor
663  * @type:	Type of returned scale values
666  * Drivers which do not allow scale setting to change integration time can
694  * @gts:	Gain time scale descriptor
696  * @type:	Type of returned scale values
717  * @gts:	Gain time scale descriptor
737  * @gts:	Gain time scale descriptor
757  * @gts:	Gain time scale descriptor
780  * @gts:	Gain time scale descriptor
852  * iio_gts_find_gain_for_scale_using_time - Find gain by time and scale
853  * @gts:	Gain time scale descriptor
856  * @scale_int:	Integral part of the scale (typically val1)
857  * @scale_nano:	Fractional part of the scale (nano or ppb)
861  * corresponds given scale and integration time. Sensors which fill the
896  * @gts:	Gain time scale descriptor
899  * @scale_int:	Integral part of the scale (typically val1)
900  * @scale_nano:	Fractional part of the scale (nano or ppb)
944 				    u64 *scale)  in iio_gts_get_scale_linear()  argument
957 	*scale = tmp;  in iio_gts_get_scale_linear()
963  * iio_gts_get_scale - get scale based on integration time and HW-gain
964  * @gts:	Gain time scale descriptor
965  * @gain:	HW-gain for which the scale is computed
966  * @time:	Integration time for which the scale is computed
967  * @scale_int:	Integral part of the scale (typically val1)
968  * @scale_nano:	Fractional part of the scale (nano or ppb)
970  * Compute scale matching the integration time and HW-gain given as parameter.
990  * @gts:		Gain time scale descriptor
996  * We may want to mitigate the scale change caused by setting a new integration
998  * new gain value to maintain the scale with new integration time.
1006  * gain required to maintain the scale would not be an integer. In this case,
1015 	u64 scale;  in iio_gts_find_new_gain_sel_by_old_gain_time()  local
1029 				       &scale);  in iio_gts_find_new_gain_sel_by_old_gain_time()
1033 	ret = gain_get_scale_fraction(gts->max_scale, scale, itime_new->mul,  in iio_gts_find_new_gain_sel_by_old_gain_time()
1047  * @gts:		Gain time scale descriptor
1053  * We may want to mitigate the scale change caused by setting a new integration
1055  * new gain value to maintain the scale with new integration time.
1063  * gain required to maintain the scale would not be an integer. In this case,
1072 	u64 scale;  in iio_gts_find_new_gain_by_old_gain_time()  local
1081 	ret = iio_gts_get_scale_linear(gts, old_gain, old_time, &scale);  in iio_gts_find_new_gain_by_old_gain_time()
1085 	ret = gain_get_scale_fraction(gts->max_scale, scale, itime_new->mul,  in iio_gts_find_new_gain_by_old_gain_time()
1099 MODULE_DESCRIPTION("IIO light sensor gain-time-scale helpers");