98  * Available scales with gain 1x - 1024x, timings 55, 100, 200, 400 mS
99  * Time impacts to gain: 1x, 2x, 4x, 8x.
101  * => Max total gain is HWGAIN * gain by integration time (8 * 1024) = 8192
102  * if 1x gain is scale 1, scale for 2x gain is 0.5, 4x => 0.25,
105  * Using NANO precision for scale, we must use scale 16x corresponding gain 1x
110 /* See the data sheet for the "Gain Setting" table */
118 /* Available gain settings */
130  * multiplying impact to the data register values (similar to gain).
133  * the scale is doubled. Eg, time impact to total gain is x1, x2, x4, x8.
199 	 * Protect gain and time during scale adjustment and data reading.
276 static int bu27034_get_gain(struct bu27034_data *data, int chan, int *gain)  in bu27034_get_gain()  argument
288 		dev_err(data->dev, "chan %u: unknown gain value 0x%x\n", chan,  in bu27034_get_gain()
294 	*gain = ret;  in bu27034_get_gain()
314 	int gain, ret;  in _bu27034_get_scale()  local
316 	ret = bu27034_get_gain(data, channel, &gain);  in _bu27034_get_scale()
324 	return iio_gts_get_scale(&data->gts, gain, ret, val, val2);  in _bu27034_get_scale()
362 static int bu27034_set_gain(struct bu27034_data *data, int chan, int gain)  in bu27034_set_gain()  argument
366 	ret = iio_gts_find_sel_by_gain(&data->gts, gain);  in bu27034_set_gain()
388  * given channels by adjusting gain so that it compensates the time change.
447 					"optimal gain out of range for chan %u\n",  in bu27034_try_set_int_time()
452 					 "Total gain increase. Risk of saturation");  in bu27034_try_set_int_time()
460 			dev_dbg(data->dev, "chan %u new gain %u\n",  in bu27034_try_set_int_time()
499 		struct bu27034_gain_check gain;  in bu27034_set_scale()  local
507 			gain.chan = BU27034_CHAN_DATA1;  in bu27034_set_scale()
509 			gain.chan = BU27034_CHAN_DATA0;  in bu27034_set_scale()
511 		ret = bu27034_get_gain(data, gain.chan, &gain.old_gain);  in bu27034_set_scale()
535 				&data->gts, gain.old_gain, time_sel,  in bu27034_set_scale()
536 				new_time_sel, &gain.new_gain);  in bu27034_set_scale()
549 		ret = bu27034_set_gain(data, gain.chan, gain.new_gain);  in bu27034_set_scale()
605 static inline u64 gain_mul_div_helper(u64 val, unsigned int gain,  in gain_mul_div_helper()  argument
609 	 * Max gain for a channel is 4096. The max u64 (0xffffffffffffffffULL)  in gain_mul_div_helper()
612 	 * with the gain, no matter what gain is set.  in gain_mul_div_helper()
614 	 * So, multiplication with max gain may overflow if val is greater than  in gain_mul_div_helper()
620 		val *= gain;  in gain_mul_div_helper()
624 		val *= gain;  in gain_mul_div_helper()
679 				 unsigned int gain)  in bu27034_fixp_calc_t23()  argument
685 		return helper / gain;  in bu27034_fixp_calc_t23()
688 	do_div(helper64, gain);  in bu27034_fixp_calc_t23()
766  * any gain / integration time configuration registers) The bit gets
1191 			 * The maximum Milli lux value we get with gain 1x time  in bu27034_buffer_thread()