250 lines
5.4 KiB
C
250 lines
5.4 KiB
C
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/*
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* AD5446 SPI DAC 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/interrupt.h>
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#include <linux/workqueue.h>
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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/list.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 "../iio.h"
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#include "../sysfs.h"
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#include "dac.h"
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#include "ad5446.h"
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static ssize_t ad5446_write(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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struct iio_dev *dev_info = dev_get_drvdata(dev);
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struct ad5446_state *st = dev_info->dev_data;
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int ret;
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long val;
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ret = strict_strtol(buf, 10, &val);
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if (ret)
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goto error_ret;
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if (val > RES_MASK(st->chip_info->bits)) {
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ret = -EINVAL;
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goto error_ret;
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}
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mutex_lock(&dev_info->mlock);
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switch (spi_get_device_id(st->spi)->driver_data) {
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case ID_AD5444:
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case ID_AD5446:
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st->data = cpu_to_be16(AD5446_LOAD |
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(val << st->chip_info->left_shift));
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break;
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case ID_AD5542A:
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case ID_AD5512A:
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st->data = cpu_to_be16(val << st->chip_info->left_shift);
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break;
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}
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ret = spi_sync(st->spi, &st->msg);
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mutex_unlock(&dev_info->mlock);
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error_ret:
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return ret ? ret : len;
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}
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static IIO_DEV_ATTR_OUT_RAW(0, ad5446_write, 0);
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static ssize_t ad5446_show_scale(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev *dev_info = dev_get_drvdata(dev);
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struct ad5446_state *st = iio_dev_get_devdata(dev_info);
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/* Corresponds to Vref / 2^(bits) */
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unsigned int scale_uv = (st->vref_mv * 1000) >> st->chip_info->bits;
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return sprintf(buf, "%d.%d\n", scale_uv / 1000, scale_uv % 1000);
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}
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static IIO_DEVICE_ATTR(out_scale, S_IRUGO, ad5446_show_scale, NULL, 0);
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static ssize_t ad5446_show_name(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev *dev_info = dev_get_drvdata(dev);
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struct ad5446_state *st = iio_dev_get_devdata(dev_info);
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return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
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}
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static IIO_DEVICE_ATTR(name, S_IRUGO, ad5446_show_name, NULL, 0);
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static struct attribute *ad5446_attributes[] = {
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&iio_dev_attr_out0_raw.dev_attr.attr,
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&iio_dev_attr_out_scale.dev_attr.attr,
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&iio_dev_attr_name.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group ad5446_attribute_group = {
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.attrs = ad5446_attributes,
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};
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static const struct ad5446_chip_info ad5446_chip_info_tbl[] = {
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[ID_AD5444] = {
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.bits = 12,
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.storagebits = 16,
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.left_shift = 2,
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.sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
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},
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[ID_AD5446] = {
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.bits = 14,
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.storagebits = 16,
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.left_shift = 0,
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.sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
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},
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[ID_AD5542A] = {
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.bits = 16,
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.storagebits = 16,
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.left_shift = 0,
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.sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
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},
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[ID_AD5512A] = {
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.bits = 12,
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.storagebits = 16,
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.left_shift = 4,
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.sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
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},
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};
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static int __devinit ad5446_probe(struct spi_device *spi)
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{
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struct ad5446_state *st;
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int ret, voltage_uv = 0;
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st = kzalloc(sizeof(*st), GFP_KERNEL);
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if (st == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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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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&ad5446_chip_info_tbl[spi_get_device_id(spi)->driver_data];
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spi_set_drvdata(spi, st);
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st->spi = spi;
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st->indio_dev = iio_allocate_device();
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if (st->indio_dev == NULL) {
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ret = -ENOMEM;
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goto error_disable_reg;
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}
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/* Estabilish that the iio_dev is a child of the spi device */
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st->indio_dev->dev.parent = &spi->dev;
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st->indio_dev->attrs = &ad5446_attribute_group;
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st->indio_dev->dev_data = (void *)(st);
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st->indio_dev->driver_module = THIS_MODULE;
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st->indio_dev->modes = INDIO_DIRECT_MODE;
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/* Setup default message */
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st->xfer.tx_buf = &st->data,
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st->xfer.len = 2,
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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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if (voltage_uv)
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st->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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ret = iio_device_register(st->indio_dev);
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if (ret)
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goto error_free_device;
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return 0;
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error_free_device:
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iio_free_device(st->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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kfree(st);
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error_ret:
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return ret;
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}
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static int ad5446_remove(struct spi_device *spi)
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{
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struct ad5446_state *st = spi_get_drvdata(spi);
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struct iio_dev *indio_dev = st->indio_dev;
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iio_device_unregister(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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kfree(st);
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return 0;
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}
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static const struct spi_device_id ad5446_id[] = {
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{"ad5444", ID_AD5444},
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{"ad5446", ID_AD5446},
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{"ad5542a", ID_AD5542A},
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{"ad5512a", ID_AD5512A},
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{}
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};
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static struct spi_driver ad5446_driver = {
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.driver = {
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.name = "ad5446",
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.bus = &spi_bus_type,
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.owner = THIS_MODULE,
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},
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.probe = ad5446_probe,
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.remove = __devexit_p(ad5446_remove),
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.id_table = ad5446_id,
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};
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static int __init ad5446_init(void)
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{
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return spi_register_driver(&ad5446_driver);
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}
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module_init(ad5446_init);
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static void __exit ad5446_exit(void)
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{
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spi_unregister_driver(&ad5446_driver);
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}
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module_exit(ad5446_exit);
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MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
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MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("spi:ad5446");
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