1 // SPDX-License-Identifier: GPL-2.0-only
20 #define ADA4250_REG_GAIN_MUX        0x00
21 #define ADA4250_REG_REFBUF_EN       0x01
22 #define ADA4250_REG_RESET           0x02
23 #define ADA4250_REG_SNSR_CAL_VAL    0x04
24 #define ADA4250_REG_SNSR_CAL_CNFG   0x05
25 #define ADA4250_REG_DIE_REV         0x18
26 #define ADA4250_REG_CHIP_ID         0x19
29 #define ADA4250_GAIN_MUX_MSK        GENMASK(2, 0)
32 #define ADA4250_REFBUF_MSK          BIT(0)
35 #define ADA4250_RESET_MSK           BIT(0)
38 #define ADA4250_CAL_CFG_BIAS_MSK    GENMASK(7, 0)
42 #define ADA4250_RANGE_SET_MSK       GENMASK(1, 0)
45 #define ADA4250_CHIP_ID             0x4250
46 #define ADA4250_RANGE1              0
69 static const int calibbias_table[] = {0, 1, 2};
78 	.max_register = 0x1A,
87 	int i, ret, x[8], max_vos, min_vos, voltage_v, vlsb = 0;  in ada4250_set_offset_uv()
91 	if (st->bias == 0 || st->bias == 3)  in ada4250_set_offset_uv()
92 		return -EINVAL;  in ada4250_set_offset_uv()
94 	voltage_v = regulator_get_voltage(st->reg);  in ada4250_set_offset_uv()
97 	if (st->bias == ADA4250_BIAS_AVDD)  in ada4250_set_offset_uv()
98 		x[0] = voltage_v;  in ada4250_set_offset_uv()
100 		x[0] = 5;  in ada4250_set_offset_uv()
102 	x[1] = 126 * (x[0] - 1);  in ada4250_set_offset_uv()
104 	for (i = 0; i < 6; i++)  in ada4250_set_offset_uv()
107 	if (st->gain == 0)  in ada4250_set_offset_uv()
108 		return -EINVAL;  in ada4250_set_offset_uv()
115 	 *    2     |    X1*127   | X1=0.126(AVDD-1) |   X1*3*127    |  X1*3   |  in ada4250_set_offset_uv()
116 	 *    4     |    X2*127   | X2=X1/1.3333     |   X2*3*127    |  X2*3   |  in ada4250_set_offset_uv()
117 	 *    8     |    X3*127   | X3=X1/2.301      |   X3*3*127    |  X3*3   |  in ada4250_set_offset_uv()
118 	 *    16    |    X4*127   | X4=X1/4.283      |   X4*3*127    |  X4*3   |  in ada4250_set_offset_uv()
119 	 *    32    |    X5*127   | X5=X1/8.289      |   X5*3*127    |  X5*3   |  in ada4250_set_offset_uv()
120 	 *    64    |    X6*127   | X6=X1/16.311     |   X6*3*127    |  X6*3   |  in ada4250_set_offset_uv()
121 	 *    128   |    X7*127   | X7=X1/31.599     |   X7*3*127    |  X7*3   |  in ada4250_set_offset_uv()
124 		max_vos = x[st->gain] *  127 * ((1 << (i + 1)) - 1);  in ada4250_set_offset_uv()
125 		min_vos = -1 * max_vos;  in ada4250_set_offset_uv()
128 			vlsb = x[st->gain] * ((1 << (i + 1)) - 1);  in ada4250_set_offset_uv()
133 	if (vlsb <= 0)  in ada4250_set_offset_uv()
134 		return -EINVAL;  in ada4250_set_offset_uv()
138 	mutex_lock(&st->lock);  in ada4250_set_offset_uv()
139 	ret = regmap_update_bits(st->regmap, ADA4250_REG_SNSR_CAL_CNFG,  in ada4250_set_offset_uv()
145 	st->offset_uv = offset_raw * vlsb;  in ada4250_set_offset_uv()
148 	 * To set the offset calibration value, use bits [6:0] and bit 7 as the  in ada4250_set_offset_uv()
149 	 * polarity bit (set to "0" for a negative offset and "1" for a positive  in ada4250_set_offset_uv()
152 	if (offset_uv < 0) {  in ada4250_set_offset_uv()
154 		st->offset_uv *= (-1);  in ada4250_set_offset_uv()
157 	ret = regmap_write(st->regmap, ADA4250_REG_SNSR_CAL_VAL, offset_raw);  in ada4250_set_offset_uv()
160 	mutex_unlock(&st->lock);  in ada4250_set_offset_uv()
174 		ret = regmap_read(st->regmap, ADA4250_REG_GAIN_MUX, val);  in ada4250_read_raw()
182 		*val = st->offset_uv;  in ada4250_read_raw()
186 		ret = regmap_read(st->regmap, ADA4250_REG_SNSR_CAL_CNFG, val);  in ada4250_read_raw()
199 		return -EINVAL;  in ada4250_read_raw()
212 		ret = regmap_write(st->regmap, ADA4250_REG_GAIN_MUX,  in ada4250_write_raw()
217 		st->gain = ilog2(val);  in ada4250_write_raw()
223 		ret = regmap_update_bits(st->regmap, ADA4250_REG_SNSR_CAL_CNFG,  in ada4250_write_raw()
229 		st->bias = val;  in ada4250_write_raw()
233 		return -EINVAL;  in ada4250_write_raw()
256 		return -EINVAL;  in ada4250_read_avail()
268 		return regmap_read(st->regmap, reg, read_val);  in ada4250_reg_access()
270 		return regmap_write(st->regmap, reg, write_val);  in ada4250_reg_access()
285 		.channel = 0,
305 	struct spi_device *spi = st->spi;  in ada4250_init()
307 	st->refbuf_en = device_property_read_bool(&spi->dev, "adi,refbuf-enable");  in ada4250_init()
309 	st->reg = devm_regulator_get(&spi->dev, "avdd");  in ada4250_init()
310 	if (IS_ERR(st->reg))  in ada4250_init()
311 		return dev_err_probe(&spi->dev, PTR_ERR(st->reg),  in ada4250_init()
314 	ret = regulator_enable(st->reg);  in ada4250_init()
316 		dev_err(&spi->dev, "Failed to enable specified AVDD supply\n");  in ada4250_init()
320 	ret = devm_add_action_or_reset(&spi->dev, ada4250_reg_disable, st->reg);  in ada4250_init()
324 	ret = regmap_write(st->regmap, ADA4250_REG_RESET,  in ada4250_init()
329 	ret = regmap_bulk_read(st->regmap, ADA4250_REG_CHIP_ID, data, 2);  in ada4250_init()
336 		dev_err(&spi->dev, "Invalid chip ID.\n");  in ada4250_init()
337 		return -EINVAL;  in ada4250_init()
340 	return regmap_write(st->regmap, ADA4250_REG_REFBUF_EN,  in ada4250_init()
341 			    FIELD_PREP(ADA4250_REFBUF_MSK, st->refbuf_en));  in ada4250_init()
351 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));  in ada4250_probe()
353 		return -ENOMEM;  in ada4250_probe()
360 	st->regmap = regmap;  in ada4250_probe()
361 	st->spi = spi;  in ada4250_probe()
363 	indio_dev->info = &ada4250_info;  in ada4250_probe()
364 	indio_dev->name = "ada4250";  in ada4250_probe()
365 	indio_dev->channels = ada4250_channels;  in ada4250_probe()
366 	indio_dev->num_channels = ARRAY_SIZE(ada4250_channels);  in ada4250_probe()
368 	mutex_init(&st->lock);  in ada4250_probe()
372 		dev_err(&spi->dev, "ADA4250 init failed\n");  in ada4250_probe()
376 	return devm_iio_device_register(&spi->dev, indio_dev);  in ada4250_probe()
380 	{ "ada4250", 0 },