iio: amplifiers: New driver for AD8366 Dual-Digital Variable Gain Amplifier
Changes since V1: Apply review feedback: Introduce and use IIO_CHAN_INFO_HARDWAREGAIN Introduce and use Use IIO_VAL_INT_PLUS_MICRO_DB Modify out of staging include paths. Convert to new iio core API naming. Changes since V2: more sanity checking in write_raw Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Michael Hennerich
Greg Kroah-Hartman
parent
b65d62122f
commit
e71d42e03c
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@ -48,4 +48,6 @@ config IIO_CONSUMERS_PER_TRIGGER
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This value controls the maximum number of consumers that a
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given trigger may handle. Default is 2.
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source "drivers/iio/amplifiers/Kconfig"
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endif # IIO
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@ -8,3 +8,5 @@ industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
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industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
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obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
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obj-y += amplifiers/
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@ -0,0 +1,17 @@
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#
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# Gain Amplifiers, etc.
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#
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menu "Amplifiers"
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config AD8366
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tristate "Analog Devices AD8366 VGA"
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depends on SPI
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select BITREVERSE
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help
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Say yes here to build support for Analog Devices AD8366
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SPI Dual-Digital Variable Gain Amplifier (VGA).
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To compile this driver as a module, choose M here: the
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module will be called ad8366.
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endmenu
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@ -0,0 +1,5 @@
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#
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# Makefile iio/amplifiers
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#
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obj-$(CONFIG_AD8366) += ad8366.o
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@ -0,0 +1,222 @@
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/*
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* AD8366 SPI Dual-Digital Variable Gain Amplifier (VGA)
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*
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* Copyright 2012 Analog Devices Inc.
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*
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* Licensed under the GPL-2.
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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 <linux/bitrev.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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struct ad8366_state {
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struct spi_device *spi;
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struct regulator *reg;
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unsigned char ch[2];
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/*
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* DMA (thus cache coherency maintenance) requires the
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* transfer buffers to live in their own cache lines.
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*/
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unsigned char data[2] ____cacheline_aligned;
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};
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static int ad8366_write(struct iio_dev *indio_dev,
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unsigned char ch_a, char unsigned ch_b)
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{
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struct ad8366_state *st = iio_priv(indio_dev);
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int ret;
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ch_a = bitrev8(ch_a & 0x3F);
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ch_b = bitrev8(ch_b & 0x3F);
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st->data[0] = ch_b >> 4;
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st->data[1] = (ch_b << 4) | (ch_a >> 2);
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ret = spi_write(st->spi, st->data, ARRAY_SIZE(st->data));
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if (ret < 0)
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dev_err(&indio_dev->dev, "write failed (%d)", ret);
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return ret;
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}
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static int ad8366_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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struct ad8366_state *st = iio_priv(indio_dev);
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int ret;
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unsigned code;
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mutex_lock(&indio_dev->mlock);
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switch (m) {
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case IIO_CHAN_INFO_HARDWAREGAIN:
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code = st->ch[chan->channel];
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/* Values in dB */
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code = code * 253 + 4500;
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*val = code / 1000;
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*val2 = (code % 1000) * 1000;
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ret = IIO_VAL_INT_PLUS_MICRO_DB;
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break;
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default:
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ret = -EINVAL;
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}
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mutex_unlock(&indio_dev->mlock);
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return ret;
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};
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static int ad8366_write_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 mask)
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{
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struct ad8366_state *st = iio_priv(indio_dev);
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unsigned code;
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int ret;
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if (val < 0 || val2 < 0)
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return -EINVAL;
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/* Values in dB */
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code = (((u8)val * 1000) + ((u32)val2 / 1000));
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if (code > 20500 || code < 4500)
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return -EINVAL;
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code = (code - 4500) / 253;
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mutex_lock(&indio_dev->mlock);
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switch (mask) {
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case IIO_CHAN_INFO_HARDWAREGAIN:
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st->ch[chan->channel] = code;
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ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
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break;
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default:
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ret = -EINVAL;
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}
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mutex_unlock(&indio_dev->mlock);
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return ret;
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}
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static const struct iio_info ad8366_info = {
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.read_raw = &ad8366_read_raw,
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.write_raw = &ad8366_write_raw,
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.driver_module = THIS_MODULE,
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};
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#define AD8366_CHAN(_channel) { \
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.type = IIO_VOLTAGE, \
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.output = 1, \
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.indexed = 1, \
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.channel = _channel, \
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.info_mask = IIO_CHAN_INFO_HARDWAREGAIN_SEPARATE_BIT,\
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}
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static const struct iio_chan_spec ad8366_channels[] = {
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AD8366_CHAN(0),
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AD8366_CHAN(1),
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};
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static int __devinit ad8366_probe(struct spi_device *spi)
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{
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struct iio_dev *indio_dev;
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struct ad8366_state *st;
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int ret;
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indio_dev = iio_device_alloc(sizeof(*st));
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if (indio_dev == NULL)
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return -ENOMEM;
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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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}
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spi_set_drvdata(spi, indio_dev);
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st->spi = spi;
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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->info = &ad8366_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = ad8366_channels;
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indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_disable_reg;
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ad8366_write(indio_dev, 0 , 0);
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return 0;
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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_device_free(indio_dev);
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return ret;
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}
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static int __devexit ad8366_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 ad8366_state *st = iio_priv(indio_dev);
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struct regulator *reg = st->reg;
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iio_device_unregister(indio_dev);
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if (!IS_ERR(reg)) {
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regulator_disable(reg);
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regulator_put(reg);
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}
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iio_device_free(indio_dev);
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return 0;
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}
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static const struct spi_device_id ad8366_id[] = {
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{"ad8366", 0},
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{}
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};
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static struct spi_driver ad8366_driver = {
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.driver = {
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.name = KBUILD_MODNAME,
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.owner = THIS_MODULE,
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},
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.probe = ad8366_probe,
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.remove = __devexit_p(ad8366_remove),
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.id_table = ad8366_id,
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};
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module_spi_driver(ad8366_driver);
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MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
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MODULE_DESCRIPTION("Analog Devices AD8366 VGA");
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MODULE_LICENSE("GPL v2");
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