256 lines
6.4 KiB
C
256 lines
6.4 KiB
C
/*
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* AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
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*
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* Copyright 2010 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/spi/spi.h>
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#include <linux/regulator/consumer.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include "../iio.h"
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#include "../sysfs.h"
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#include "../buffer.h"
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#include "ad7476.h"
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static int ad7476_scan_direct(struct ad7476_state *st)
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{
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int ret;
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ret = spi_sync(st->spi, &st->msg);
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if (ret)
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return ret;
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return (st->data[0] << 8) | st->data[1];
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}
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static int ad7476_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val,
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int *val2,
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long m)
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{
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int ret;
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struct ad7476_state *st = iio_priv(indio_dev);
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unsigned int scale_uv;
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switch (m) {
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case 0:
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mutex_lock(&indio_dev->mlock);
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if (iio_buffer_enabled(indio_dev))
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ret = -EBUSY;
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else
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ret = ad7476_scan_direct(st);
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mutex_unlock(&indio_dev->mlock);
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if (ret < 0)
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return ret;
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*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
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RES_MASK(st->chip_info->channel[0].scan_type.realbits);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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scale_uv = (st->int_vref_mv * 1000)
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>> st->chip_info->channel[0].scan_type.realbits;
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*val = scale_uv/1000;
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*val2 = (scale_uv%1000)*1000;
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return IIO_VAL_INT_PLUS_MICRO;
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}
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return -EINVAL;
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}
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static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
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[ID_AD7466] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 12, 16, 0), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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},
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[ID_AD7467] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 10, 16, 2), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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},
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[ID_AD7468] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1 , 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 8, 16, 4), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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},
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[ID_AD7475] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 12, 16, 0), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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},
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[ID_AD7476] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 12, 16, 0), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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},
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[ID_AD7477] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 10, 16, 2), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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},
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[ID_AD7478] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 8, 16, 4), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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},
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[ID_AD7495] = {
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.channel[0] = IIO_CHAN(IIO_VOLTAGE, 0, 1, 0, NULL, 0, 0,
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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0, 0, IIO_ST('u', 12, 16, 0), 0),
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.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
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.int_vref_mv = 2500,
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},
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};
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static const struct iio_info ad7476_info = {
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.driver_module = THIS_MODULE,
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.read_raw = &ad7476_read_raw,
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};
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static int __devinit ad7476_probe(struct spi_device *spi)
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{
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struct ad7476_platform_data *pdata = spi->dev.platform_data;
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struct ad7476_state *st;
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struct iio_dev *indio_dev;
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int ret, voltage_uv = 0;
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indio_dev = iio_allocate_device(sizeof(*st));
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if (indio_dev == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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st = iio_priv(indio_dev);
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st->reg = regulator_get(&spi->dev, "vcc");
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if (!IS_ERR(st->reg)) {
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ret = regulator_enable(st->reg);
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if (ret)
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goto error_put_reg;
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voltage_uv = regulator_get_voltage(st->reg);
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}
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st->chip_info =
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&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
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if (st->chip_info->int_vref_mv)
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st->int_vref_mv = st->chip_info->int_vref_mv;
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else if (pdata && pdata->vref_mv)
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st->int_vref_mv = pdata->vref_mv;
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else if (voltage_uv)
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st->int_vref_mv = voltage_uv / 1000;
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else
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dev_warn(&spi->dev, "reference voltage unspecified\n");
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spi_set_drvdata(spi, indio_dev);
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st->spi = spi;
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/* Establish that the iio_dev is a child of the spi device */
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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->channels = st->chip_info->channel;
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indio_dev->num_channels = 2;
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indio_dev->info = &ad7476_info;
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/* Setup default message */
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st->xfer.rx_buf = &st->data;
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st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;
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spi_message_init(&st->msg);
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spi_message_add_tail(&st->xfer, &st->msg);
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ret = ad7476_register_ring_funcs_and_init(indio_dev);
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if (ret)
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goto error_disable_reg;
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ret = iio_buffer_register(indio_dev,
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st->chip_info->channel,
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ARRAY_SIZE(st->chip_info->channel));
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if (ret)
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goto error_cleanup_ring;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_ring_unregister;
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return 0;
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error_ring_unregister:
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iio_buffer_unregister(indio_dev);
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error_cleanup_ring:
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ad7476_ring_cleanup(indio_dev);
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error_disable_reg:
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if (!IS_ERR(st->reg))
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regulator_disable(st->reg);
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error_put_reg:
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if (!IS_ERR(st->reg))
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regulator_put(st->reg);
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iio_free_device(indio_dev);
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error_ret:
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return ret;
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}
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static int ad7476_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 ad7476_state *st = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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iio_buffer_unregister(indio_dev);
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ad7476_ring_cleanup(indio_dev);
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if (!IS_ERR(st->reg)) {
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regulator_disable(st->reg);
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regulator_put(st->reg);
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}
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iio_free_device(indio_dev);
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return 0;
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}
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static const struct spi_device_id ad7476_id[] = {
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{"ad7466", ID_AD7466},
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{"ad7467", ID_AD7467},
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{"ad7468", ID_AD7468},
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{"ad7475", ID_AD7475},
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{"ad7476", ID_AD7476},
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{"ad7476a", ID_AD7476},
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{"ad7477", ID_AD7477},
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{"ad7477a", ID_AD7477},
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{"ad7478", ID_AD7478},
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{"ad7478a", ID_AD7478},
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{"ad7495", ID_AD7495},
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{}
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};
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MODULE_DEVICE_TABLE(spi, ad7476_id);
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static struct spi_driver ad7476_driver = {
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.driver = {
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.name = "ad7476",
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.owner = THIS_MODULE,
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},
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.probe = ad7476_probe,
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.remove = __devexit_p(ad7476_remove),
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.id_table = ad7476_id,
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};
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module_spi_driver(ad7476_driver);
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MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
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MODULE_DESCRIPTION("Analog Devices AD7475/6/7/8(A) AD7466/7/8 ADC");
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MODULE_LICENSE("GPL v2");
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