97  * Available scales with gain 1x - 1024x, timings 55, 100, 200, 400 mS
98  * Time impacts to gain: 1x, 2x, 4x, 8x.
100  * => Max total gain is HWGAIN * gain by integration time (8 * 1024) = 8192
101  * if 1x gain is scale 1, scale for 2x gain is 0.5, 4x => 0.25,
104  * Using NANO precision for scale, we must use scale 16x corresponding gain 1x
109 /* See the data sheet for the "Gain Setting" table */
117 /* Available gain settings */
129  * multiplying impact to the data register values (similar to gain).
132  * the scale is doubled. Eg, time impact to total gain is x1, x2, x4, x8.
198 	 * Protect gain and time during scale adjustment and data reading.
275 static int bu27034_get_gain(struct bu27034_data *data, int chan, int *gain)  in bu27034_get_gain()  argument
287 		dev_err(data->dev, "chan %u: unknown gain value 0x%x\n", chan,  in bu27034_get_gain()
293 	*gain = ret;  in bu27034_get_gain()
313 	int gain, ret;  in _bu27034_get_scale()  local
315 	ret = bu27034_get_gain(data, channel, &gain);  in _bu27034_get_scale()
323 	return iio_gts_get_scale(&data->gts, gain, ret, val, val2);  in _bu27034_get_scale()
361 static int bu27034_set_gain(struct bu27034_data *data, int chan, int gain)  in bu27034_set_gain()  argument
365 	ret = iio_gts_find_sel_by_gain(&data->gts, gain);  in bu27034_set_gain()
387  * given channels by adjusting gain so that it compensates the time change.
450 					"optimal gain out of range for chan %u\n",  in bu27034_try_set_int_time()
455 					 "Total gain increase. Risk of saturation");  in bu27034_try_set_int_time()
463 			dev_dbg(data->dev, "chan %u new gain %u\n",  in bu27034_try_set_int_time()
507 		struct bu27034_gain_check gain;  in bu27034_set_scale()  local
515 			gain.chan = BU27034_CHAN_DATA1;  in bu27034_set_scale()
517 			gain.chan = BU27034_CHAN_DATA0;  in bu27034_set_scale()
519 		ret = bu27034_get_gain(data, gain.chan, &gain.old_gain);  in bu27034_set_scale()
543 				&data->gts, gain.old_gain, time_sel,  in bu27034_set_scale()
544 				new_time_sel, &gain.new_gain);  in bu27034_set_scale()
559 		ret = bu27034_set_gain(data, gain.chan, gain.new_gain);  in bu27034_set_scale()
619 static inline u64 gain_mul_div_helper(u64 val, unsigned int gain,  in gain_mul_div_helper()  argument
623 	 * Max gain for a channel is 4096. The max u64 (0xffffffffffffffffULL)  in gain_mul_div_helper()
626 	 * with the gain, no matter what gain is set.  in gain_mul_div_helper()
628 	 * So, multiplication with max gain may overflow if val is greater than  in gain_mul_div_helper()
634 		val *= gain;  in gain_mul_div_helper()
638 		val *= gain;  in gain_mul_div_helper()
693 				 unsigned int gain)  in bu27034_fixp_calc_t23()  argument
699 		return helper / gain;  in bu27034_fixp_calc_t23()
702 	do_div(helper64, gain);  in bu27034_fixp_calc_t23()
780  * any gain / integration time configuration registers) The bit gets
1205 			 * The maximum Milli lux value we get with gain 1x time  in bu27034_buffer_thread()