1 // SPDX-License-Identifier: GPL-2.0
6  * Copyright (C) 2016-17 Renesas Electronics Corporation
7  * Copyright (C) 2016-17 Jacopo Mondi
14 #include <linux/spi/spi.h>
20  * LSB is the ADC single digital step
21  * 1 LSB = (vref_mv / 2 ^ 16)
23  * LSB is used to calculate analog voltage value
26  * Ain = (count * LSB)
32 	struct spi_device *spi;  member
54 	ret = spi_read(state->spi, state->buffer, sizeof(state->buffer));  in max11100_read_single()
56 		dev_err(&indio_dev->dev, "SPI transfer failed\n");  in max11100_read_single()
60 	/* the first 8 bits sent out from ADC must be 0s */  in max11100_read_single()
61 	if (state->buffer[0]) {  in max11100_read_single()
62 		dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n");  in max11100_read_single()
63 		return -EINVAL;  in max11100_read_single()
66 	*val = (state->buffer[1] << 8) | state->buffer[2];  in max11100_read_single()
87 		vref_uv = regulator_get_voltage(state->vref_reg);  in max11100_read_raw()
89 			/* dummy regulator "get_voltage" returns -EINVAL */  in max11100_read_raw()
90 			return -EINVAL;  in max11100_read_raw()
97 	return -EINVAL;  in max11100_read_raw()
104 static int max11100_probe(struct spi_device *spi)  in max11100_probe()  argument
110 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));  in max11100_probe()
112 		return -ENOMEM;  in max11100_probe()
114 	spi_set_drvdata(spi, indio_dev);  in max11100_probe()
117 	state->spi = spi;  in max11100_probe()
119 	indio_dev->name = "max11100";  in max11100_probe()
120 	indio_dev->info = &max11100_info;  in max11100_probe()
121 	indio_dev->modes = INDIO_DIRECT_MODE;  in max11100_probe()
122 	indio_dev->channels = max11100_channels;  in max11100_probe()
123 	indio_dev->num_channels = ARRAY_SIZE(max11100_channels);  in max11100_probe()
125 	state->vref_reg = devm_regulator_get(&spi->dev, "vref");  in max11100_probe()
126 	if (IS_ERR(state->vref_reg))  in max11100_probe()
127 		return PTR_ERR(state->vref_reg);  in max11100_probe()
129 	ret = regulator_enable(state->vref_reg);  in max11100_probe()
140 	regulator_disable(state->vref_reg);  in max11100_probe()
145 static int max11100_remove(struct spi_device *spi)  in max11100_remove()  argument
147 	struct iio_dev *indio_dev = spi_get_drvdata(spi);  in max11100_remove()
151 	regulator_disable(state->vref_reg);  in max11100_remove()