3  * HMC425A and similar Gain Amplifiers
26  * The LTC6373 amplifier supports configuring gain using GPIO's with the following
30  * From here, it is observed that all values are multiples of the '2' gain setting,
56 	int				(*gain_dB_to_code)(int gain, int *code);
64 	u32	gain;  member
71 	int gain;  in gain_dB_to_code()  local
74 		gain = (val * 1000) - (val2 / 1000);  in gain_dB_to_code()
76 		gain = (val * 1000) + (val2 / 1000);  in gain_dB_to_code()
78 	if (gain > inf->gain_max || gain < inf->gain_min)  in gain_dB_to_code()
83 	return st->chip_info->gain_dB_to_code(gain, code);  in gain_dB_to_code()
86 static int hmc425a_gain_dB_to_code(int gain, int *code)  in hmc425a_gain_dB_to_code()  argument
88 	*code = ~((abs(gain) / 500) & 0x3F);  in hmc425a_gain_dB_to_code()
92 static int hmc540s_gain_dB_to_code(int gain, int *code)  in hmc540s_gain_dB_to_code()  argument
94 	*code = ~((abs(gain) / 1000) & 0xF);  in hmc540s_gain_dB_to_code()
98 static int adrf5740_gain_dB_to_code(int gain, int *code)  in adrf5740_gain_dB_to_code()  argument
100 	int temp = (abs(gain) / 2000) & 0xF;  in adrf5740_gain_dB_to_code()
107 static int ltc6373_gain_dB_to_code(int gain, int *code)  in ltc6373_gain_dB_to_code()  argument
109 	*code = ~(DIV_ROUND_CLOSEST(gain, LTC6373_CONVERSION_CONSTANT) + 3)  in ltc6373_gain_dB_to_code()
118 	return st->chip_info->code_to_gain_dB(st->gain, val, val2);  in code_to_gain_dB()
149 	int gain = ((~code & LTC6373_CONVERSION_MASK) - 3) *  in ltc6373_code_to_gain_dB()  local
152 	*val = gain / 1000;  in ltc6373_code_to_gain_dB()
153 	*val2 = (gain % 1000) * 1000;  in ltc6373_code_to_gain_dB()
205 		st->gain = code;  in hmc425a_write_raw()
207 		ret = hmc425a_write(indio_dev, st->gain);  in hmc425a_write_raw()
261 	code = (powerdown) ? LTC6373_SHUTDOWN : st->gain;  in ltc6373_write_powerdown()
312 		.default_gain = -0x40, /* set default gain -31.5db*/
323 		.default_gain = -0x10, /* set default gain -15.0db*/
334 		.default_gain = 0xF, /* set default gain -22.0db*/
343 		.gain_min = -12041, /* gain setting x0.25*/
344 		.gain_max = 24082,  /* gain setting x16  */
369 	st->gain = st->chip_info->default_gain;  in hmc425a_probe()
395 		/* Set default gain */  in hmc425a_probe()
396 		hmc425a_write(indio_dev, st->gain);  in hmc425a_probe()
426 MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO control Gain Amplifiers");