![Angelo Compagnucci](/assets/img/avatar_default.png)
This patch adds support for ADC128S052 from TI. Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
180 lines
3.7 KiB
C
180 lines
3.7 KiB
C
/*
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* Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
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*
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* Driver for Texas Instruments' ADC128S052 ADC chip.
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* Datasheet can be found here:
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* http://www.ti.com/lit/ds/symlink/adc128s052.pdf
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/err.h>
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#include <linux/spi/spi.h>
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#include <linux/module.h>
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#include <linux/iio/iio.h>
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#include <linux/regulator/consumer.h>
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struct adc128 {
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struct spi_device *spi;
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struct regulator *reg;
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struct mutex lock;
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u8 buffer[2] ____cacheline_aligned;
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};
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static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
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{
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int ret;
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mutex_lock(&adc->lock);
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adc->buffer[0] = channel << 3;
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adc->buffer[1] = 0;
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ret = spi_write(adc->spi, &adc->buffer, 2);
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if (ret < 0) {
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mutex_unlock(&adc->lock);
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return ret;
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}
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ret = spi_read(adc->spi, &adc->buffer, 2);
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mutex_unlock(&adc->lock);
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if (ret < 0)
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return ret;
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return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
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}
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static int adc128_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *channel, int *val,
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int *val2, long mask)
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{
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struct adc128 *adc = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = adc128_adc_conversion(adc, channel->channel);
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if (ret < 0)
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return ret;
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*val = ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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ret = regulator_get_voltage(adc->reg);
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if (ret < 0)
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return ret;
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*val = ret / 1000;
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*val2 = 12;
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return IIO_VAL_FRACTIONAL_LOG2;
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default:
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return -EINVAL;
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}
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}
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#define ADC128_VOLTAGE_CHANNEL(num) \
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{ \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.channel = (num), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
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}
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static const struct iio_chan_spec adc128_channels[] = {
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ADC128_VOLTAGE_CHANNEL(0),
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ADC128_VOLTAGE_CHANNEL(1),
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ADC128_VOLTAGE_CHANNEL(2),
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ADC128_VOLTAGE_CHANNEL(3),
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ADC128_VOLTAGE_CHANNEL(4),
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ADC128_VOLTAGE_CHANNEL(5),
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ADC128_VOLTAGE_CHANNEL(6),
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ADC128_VOLTAGE_CHANNEL(7),
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};
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static const struct iio_info adc128_info = {
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.read_raw = adc128_read_raw,
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.driver_module = THIS_MODULE,
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};
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static int adc128_probe(struct spi_device *spi)
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{
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struct iio_dev *indio_dev;
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struct adc128 *adc;
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int ret;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
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if (!indio_dev)
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return -ENOMEM;
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adc = iio_priv(indio_dev);
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adc->spi = spi;
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spi_set_drvdata(spi, indio_dev);
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indio_dev->dev.parent = &spi->dev;
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indio_dev->name = spi_get_device_id(spi)->name;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->info = &adc128_info;
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indio_dev->channels = adc128_channels;
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indio_dev->num_channels = ARRAY_SIZE(adc128_channels);
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adc->reg = devm_regulator_get(&spi->dev, "vref");
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if (IS_ERR(adc->reg))
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return PTR_ERR(adc->reg);
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ret = regulator_enable(adc->reg);
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if (ret < 0)
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return ret;
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mutex_init(&adc->lock);
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ret = iio_device_register(indio_dev);
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return ret;
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}
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static int adc128_remove(struct spi_device *spi)
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{
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struct iio_dev *indio_dev = spi_get_drvdata(spi);
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struct adc128 *adc = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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regulator_disable(adc->reg);
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return 0;
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}
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static const struct spi_device_id adc128_id[] = {
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{ "adc128s052", 0},
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{ }
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};
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MODULE_DEVICE_TABLE(spi, adc128_id);
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static struct spi_driver adc128_driver = {
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.driver = {
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.name = "adc128s052",
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.owner = THIS_MODULE,
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},
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.probe = adc128_probe,
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.remove = adc128_remove,
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.id_table = adc128_id,
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};
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module_spi_driver(adc128_driver);
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MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
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MODULE_DESCRIPTION("Texas Instruments ADC128S052");
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MODULE_LICENSE("GPL v2");
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