iio: add mcp4725 I2C DAC driver
v5: * fix warnings (Jonathan Cameron) v4: * remove unused indio_dev pointer in mcp4725_data (Jonathan Cameron) * use u16 instead of unsigned short in mcp4725_data (Jonathan Cameron) * #include mcp4725.h from linux/iio/dac/ v3: * move from staging to drivers/iio * switch to chan_spec * dev_get_drvdata() -> dev_to_iio_dev() * annotate probe() and remove() with __devinit and __devexit v2 (based on comments from Jonathan Cameron and Lars-Peter Clausen): * did NOT switch to chan_spec yet * rebase to staging-next tree, update iio header locations * dropped dac.h #include, not needed * strict_strtol() -> kstrtol() * call iio_device_unregister() in remove() * everything in one patch Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Meerwald
Greg Kroah-Hartman
parent
1a135d1ab5
commit
cf35ad61ac
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@ -118,4 +118,15 @@ config MAX517
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This driver can also be built as a module. If so, the module
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will be called max517.
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config MCP4725
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tristate "MCP4725 DAC driver"
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depends on I2C
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---help---
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Say Y here if you want to build a driver for the Microchip
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MCP 4725 12-bit digital-to-analog converter (DAC) with I2C
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interface.
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To compile this driver as a module, choose M here: the module
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will be called mcp4725.
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endmenu
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@ -13,3 +13,4 @@ obj-$(CONFIG_AD5764) += ad5764.o
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obj-$(CONFIG_AD5791) += ad5791.o
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obj-$(CONFIG_AD5686) += ad5686.o
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obj-$(CONFIG_MAX517) += max517.o
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obj-$(CONFIG_MCP4725) += mcp4725.o
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227
drivers/iio/dac/mcp4725.c
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227
drivers/iio/dac/mcp4725.c
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@ -0,0 +1,227 @@
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/*
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* mcp4725.c - Support for Microchip MCP4725
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*
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* Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
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*
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* Based on max517 by Roland Stigge <stigge@antcom.de>
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*
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* This file is subject to the terms and conditions of version 2 of
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* the GNU General Public License. See the file COPYING in the main
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* directory of this archive for more details.
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*
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* driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
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* (7-bit I2C slave address 0x60, the three LSBs can be configured in
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* hardware)
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*
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* writing the DAC value to EEPROM is not supported
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/err.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/dac/mcp4725.h>
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#define MCP4725_DRV_NAME "mcp4725"
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struct mcp4725_data {
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struct i2c_client *client;
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u16 vref_mv;
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u16 dac_value;
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};
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#ifdef CONFIG_PM_SLEEP
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static int mcp4725_suspend(struct device *dev)
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{
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u8 outbuf[2];
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outbuf[0] = 0x3 << 4; /* power-down bits, 500 kOhm resistor */
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outbuf[1] = 0;
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return i2c_master_send(to_i2c_client(dev), outbuf, 2);
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}
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static int mcp4725_resume(struct device *dev)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct mcp4725_data *data = iio_priv(indio_dev);
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u8 outbuf[2];
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/* restore previous DAC value */
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outbuf[0] = (data->dac_value >> 8) & 0xf;
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outbuf[1] = data->dac_value & 0xff;
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return i2c_master_send(to_i2c_client(dev), outbuf, 2);
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}
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static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
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#define MCP4725_PM_OPS (&mcp4725_pm_ops)
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#else
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#define MCP4725_PM_OPS NULL
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#endif
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static const struct iio_chan_spec mcp4725_channel = {
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.type = IIO_VOLTAGE,
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.indexed = 1,
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.output = 1,
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.channel = 0,
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.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
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IIO_CHAN_INFO_SCALE_SHARED_BIT,
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.scan_type = IIO_ST('u', 12, 16, 0),
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};
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static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
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{
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struct mcp4725_data *data = iio_priv(indio_dev);
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u8 outbuf[2];
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int ret;
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if (val >= (1 << 12) || val < 0)
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return -EINVAL;
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outbuf[0] = (val >> 8) & 0xf;
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outbuf[1] = val & 0xff;
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ret = i2c_master_send(data->client, outbuf, 2);
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if (ret < 0)
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return ret;
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else if (ret != 2)
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return -EIO;
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else
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return 0;
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}
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static int mcp4725_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct mcp4725_data *data = iio_priv(indio_dev);
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unsigned long scale_uv;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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*val = data->dac_value;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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scale_uv = (data->vref_mv * 1000) >> 12;
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*val = scale_uv / 1000000;
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*val2 = scale_uv % 1000000;
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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 int mcp4725_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct mcp4725_data *data = 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 = mcp4725_set_value(indio_dev, val);
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data->dac_value = val;
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break;
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default:
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ret = -EINVAL;
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break;
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}
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return ret;
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}
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static const struct iio_info mcp4725_info = {
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.read_raw = mcp4725_read_raw,
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.write_raw = mcp4725_write_raw,
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.driver_module = THIS_MODULE,
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};
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static int __devinit mcp4725_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct mcp4725_data *data;
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struct iio_dev *indio_dev;
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struct mcp4725_platform_data *platform_data = client->dev.platform_data;
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u8 inbuf[3];
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int err;
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if (!platform_data || !platform_data->vref_mv) {
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dev_err(&client->dev, "invalid platform data");
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err = -EINVAL;
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goto exit;
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}
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indio_dev = iio_device_alloc(sizeof(*data));
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if (indio_dev == NULL) {
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err = -ENOMEM;
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goto exit;
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}
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data = iio_priv(indio_dev);
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i2c_set_clientdata(client, indio_dev);
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data->client = client;
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indio_dev->dev.parent = &client->dev;
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indio_dev->info = &mcp4725_info;
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indio_dev->channels = &mcp4725_channel;
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indio_dev->num_channels = 1;
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indio_dev->modes = INDIO_DIRECT_MODE;
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data->vref_mv = platform_data->vref_mv;
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/* read current DAC value */
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err = i2c_master_recv(client, inbuf, 3);
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if (err < 0) {
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dev_err(&client->dev, "failed to read DAC value");
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goto exit_free_device;
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}
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data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
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err = iio_device_register(indio_dev);
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if (err)
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goto exit_free_device;
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dev_info(&client->dev, "MCP4725 DAC registered\n");
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return 0;
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exit_free_device:
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iio_device_free(indio_dev);
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exit:
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return err;
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}
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static int __devexit mcp4725_remove(struct i2c_client *client)
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{
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struct iio_dev *indio_dev = i2c_get_clientdata(client);
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iio_device_unregister(indio_dev);
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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 i2c_device_id mcp4725_id[] = {
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{ "mcp4725", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, mcp4725_id);
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static struct i2c_driver mcp4725_driver = {
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.driver = {
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.name = MCP4725_DRV_NAME,
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.pm = MCP4725_PM_OPS,
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},
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.probe = mcp4725_probe,
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.remove = __devexit_p(mcp4725_remove),
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.id_table = mcp4725_id,
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};
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module_i2c_driver(mcp4725_driver);
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MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
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MODULE_DESCRIPTION("MCP4725 12-bit DAC");
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MODULE_LICENSE("GPL");
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16
include/linux/iio/dac/mcp4725.h
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16
include/linux/iio/dac/mcp4725.h
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@ -0,0 +1,16 @@
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/*
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* MCP4725 DAC driver
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*
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* Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
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*
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* Licensed under the GPL-2 or later.
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*/
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#ifndef IIO_DAC_MCP4725_H_
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#define IIO_DAC_MCP4725_H_
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struct mcp4725_platform_data {
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u16 vref_mv;
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};
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#endif /* IIO_DAC_MCP4725_H_ */
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