Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Jacopo Mondi | 637 | 97.85% | 1 | 25.00% |
Phil Reid | 10 | 1.54% | 1 | 25.00% |
Kuninori Morimoto | 2 | 0.31% | 1 | 25.00% |
Arushi Singhal | 2 | 0.31% | 1 | 25.00% |
Total | 651 | 4 |
// SPDX-License-Identifier: GPL-2.0 /* * iio/adc/max11100.c * Maxim max11100 ADC Driver with IIO interface * * Copyright (C) 2016-17 Renesas Electronics Corporation * Copyright (C) 2016-17 Jacopo Mondi */ #include <linux/delay.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/regulator/consumer.h> #include <linux/spi/spi.h> #include <linux/iio/iio.h> #include <linux/iio/driver.h> /* * LSB is the ADC single digital step * 1 LSB = (vref_mv / 2 ^ 16) * * LSB is used to calculate analog voltage value * from the number of ADC steps count * * Ain = (count * LSB) */ #define MAX11100_LSB_DIV (1 << 16) struct max11100_state { struct regulator *vref_reg; struct spi_device *spi; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. */ u8 buffer[3] ____cacheline_aligned; }; static struct iio_chan_spec max11100_channels[] = { { /* [0] */ .type = IIO_VOLTAGE, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), }, }; static int max11100_read_single(struct iio_dev *indio_dev, int *val) { int ret; struct max11100_state *state = iio_priv(indio_dev); ret = spi_read(state->spi, state->buffer, sizeof(state->buffer)); if (ret) { dev_err(&indio_dev->dev, "SPI transfer failed\n"); return ret; } /* the first 8 bits sent out from ADC must be 0s */ if (state->buffer[0]) { dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n"); return -EINVAL; } *val = (state->buffer[1] << 8) | state->buffer[2]; return 0; } static int max11100_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long info) { int ret, vref_uv; struct max11100_state *state = iio_priv(indio_dev); switch (info) { case IIO_CHAN_INFO_RAW: ret = max11100_read_single(indio_dev, val); if (ret) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: vref_uv = regulator_get_voltage(state->vref_reg); if (vref_uv < 0) /* dummy regulator "get_voltage" returns -EINVAL */ return -EINVAL; *val = vref_uv / 1000; *val2 = MAX11100_LSB_DIV; return IIO_VAL_FRACTIONAL; } return -EINVAL; } static const struct iio_info max11100_info = { .read_raw = max11100_read_raw, }; static int max11100_probe(struct spi_device *spi) { int ret; struct iio_dev *indio_dev; struct max11100_state *state; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state)); if (!indio_dev) return -ENOMEM; spi_set_drvdata(spi, indio_dev); state = iio_priv(indio_dev); state->spi = spi; indio_dev->dev.parent = &spi->dev; indio_dev->dev.of_node = spi->dev.of_node; indio_dev->name = "max11100"; indio_dev->info = &max11100_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = max11100_channels; indio_dev->num_channels = ARRAY_SIZE(max11100_channels); state->vref_reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(state->vref_reg)) return PTR_ERR(state->vref_reg); ret = regulator_enable(state->vref_reg); if (ret) return ret; ret = iio_device_register(indio_dev); if (ret) goto disable_regulator; return 0; disable_regulator: regulator_disable(state->vref_reg); return ret; } static int max11100_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct max11100_state *state = iio_priv(indio_dev); iio_device_unregister(indio_dev); regulator_disable(state->vref_reg); return 0; } static const struct of_device_id max11100_ids[] = { {.compatible = "maxim,max11100"}, { }, }; MODULE_DEVICE_TABLE(of, max11100_ids); static struct spi_driver max11100_driver = { .driver = { .name = "max11100", .of_match_table = of_match_ptr(max11100_ids), }, .probe = max11100_probe, .remove = max11100_remove, }; module_spi_driver(max11100_driver); MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); MODULE_DESCRIPTION("Maxim max11100 ADC Driver"); MODULE_LICENSE("GPL v2");
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