iio/adc/max11100.c

1 // SPDX-License-Identifier: GPL-2.0
6  * Copyright (C) 2016-17 Renesas Electronics Corporation
7  * Copyright (C) 2016-17 Jacopo Mondi
21  * LSB is the ADC single digital step
22  * 1 LSB = (vref_mv / 2 ^ 16)
24  * LSB is used to calculate analog voltage value
27  * Ain = (count * LSB)
55 	ret = spi_read(state->spi, state->buffer, sizeof(state->buffer));  in max11100_read_single()
57 		dev_err(&indio_dev->dev, "SPI transfer failed\n");  in max11100_read_single()
61 	/* the first 8 bits sent out from ADC must be 0s */  in max11100_read_single()
62 	if (state->buffer[0]) {  in max11100_read_single()
63 		dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n");  in max11100_read_single()
64 		return -EINVAL;  in max11100_read_single()
67 	*val = get_unaligned_be16(&state->buffer[1]);  in max11100_read_single()
88 		vref_uv = regulator_get_voltage(state->vref_reg);  in max11100_read_raw()
90 			/* dummy regulator "get_voltage" returns -EINVAL */  in max11100_read_raw()
91 			return -EINVAL;  in max11100_read_raw()
98 	return -EINVAL;  in max11100_read_raw()
116 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));  in max11100_probe()
118 		return -ENOMEM;  in max11100_probe()
121 	state->spi = spi;  in max11100_probe()
123 	indio_dev->name = "max11100";  in max11100_probe()
124 	indio_dev->info = &max11100_info;  in max11100_probe()
125 	indio_dev->modes = INDIO_DIRECT_MODE;  in max11100_probe()
126 	indio_dev->channels = max11100_channels;  in max11100_probe()
127 	indio_dev->num_channels = ARRAY_SIZE(max11100_channels);  in max11100_probe()
129 	state->vref_reg = devm_regulator_get(&spi->dev, "vref");  in max11100_probe()
130 	if (IS_ERR(state->vref_reg))  in max11100_probe()
131 		return PTR_ERR(state->vref_reg);  in max11100_probe()
133 	ret = regulator_enable(state->vref_reg);  in max11100_probe()
137 	ret = devm_add_action_or_reset(&spi->dev, max11100_regulator_disable,  in max11100_probe()
138 				       state->vref_reg);  in max11100_probe()
142 	return devm_iio_device_register(&spi->dev, indio_dev);  in max11100_probe()