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/*
* max517.c - Support for Maxim MAX517, MAX518 and MAX519
*
* Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/dac/max517.h>
#define MAX517_DRV_NAME "max517"
/* Commands */
#define COMMAND_CHANNEL0 0x00
#define COMMAND_CHANNEL1 0x01 /* for MAX518 and MAX519 */
#define COMMAND_PD 0x08 /* Power Down */
enum max517_device_ids {
ID_MAX517,
ID_MAX518,
ID_MAX519,
};
struct max517_data {
struct i2c_client *client;
unsigned short vref_mv[2];
};
/*
* channel: bit 0: channel 1
* bit 1: channel 2
* (this way, it's possible to set both channels at once)
*/
static int max517_set_value(struct iio_dev *indio_dev,
long val, int channel)
{
struct max517_data *data = iio_priv(indio_dev);
struct i2c_client *client = data->client;
u8 outbuf[2];
int res;
if (val < 0 || val > 255)
return -EINVAL;
outbuf[0] = channel;
outbuf[1] = val;
res = i2c_master_send(client, outbuf, 2);
if (res < 0)
return res;
else if (res != 2)
return -EIO;
else
return 0;
}
static int max517_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct max517_data *data = iio_priv(indio_dev);
unsigned int scale_uv;
switch (m) {
case IIO_CHAN_INFO_SCALE:
/* Corresponds to Vref / 2^(bits) */
scale_uv = (data->vref_mv[chan->channel] * 1000) >> 8;
*val = scale_uv / 1000000;
*val2 = scale_uv % 1000000;
return IIO_VAL_INT_PLUS_MICRO;
default:
break;
}
return -EINVAL;
}
static int max517_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long mask)
{
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = max517_set_value(indio_dev, val, chan->channel);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
#ifdef CONFIG_PM_SLEEP
static int max517_suspend(struct device *dev)
{
u8 outbuf = COMMAND_PD;
return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
}
static int max517_resume(struct device *dev)
{
u8 outbuf = 0;
return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
}
static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
#define MAX517_PM_OPS (&max517_pm_ops)
#else
#define MAX517_PM_OPS NULL
#endif
static const struct iio_info max517_info = {
.read_raw = max517_read_raw,
.write_raw = max517_write_raw,
.driver_module = THIS_MODULE,
};
#define MAX517_CHANNEL(chan) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = (chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.scan_type = IIO_ST('u', 8, 8, 0), \
}
static const struct iio_chan_spec max517_channels[] = {
MAX517_CHANNEL(0),
MAX517_CHANNEL(1)
};
static int max517_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct max517_data *data;
struct iio_dev *indio_dev;
struct max517_platform_data *platform_data = client->dev.platform_data;
int err;
indio_dev = iio_device_alloc(sizeof(*data));
if (indio_dev == NULL) {
err = -ENOMEM;
goto exit;
}
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
/* establish that the iio_dev is a child of the i2c device */
indio_dev->dev.parent = &client->dev;
/* reduced channel set for MAX517 */
if (id->driver_data == ID_MAX517)
indio_dev->num_channels = 1;
else
indio_dev->num_channels = 2;
indio_dev->channels = max517_channels;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &max517_info;
/*
* Reference voltage on MAX518 and default is 5V, else take vref_mv
* from platform_data
*/
if (id->driver_data == ID_MAX518 || !platform_data) {
data->vref_mv[0] = data->vref_mv[1] = 5000; /* mV */
} else {
data->vref_mv[0] = platform_data->vref_mv[0];
data->vref_mv[1] = platform_data->vref_mv[1];
}
err = iio_device_register(indio_dev);
if (err)
goto exit_free_device;
dev_info(&client->dev, "DAC registered\n");
return 0;
exit_free_device:
iio_device_free(indio_dev);
exit:
return err;
}
static int max517_remove(struct i2c_client *client)
{
iio_device_unregister(i2c_get_clientdata(client));
iio_device_free(i2c_get_clientdata(client));
return 0;
}
static const struct i2c_device_id max517_id[] = {
{ "max517", ID_MAX517 },
{ "max518", ID_MAX518 },
{ "max519", ID_MAX519 },
{ }
};
MODULE_DEVICE_TABLE(i2c, max517_id);
static struct i2c_driver max517_driver = {
.driver = {
.name = MAX517_DRV_NAME,
.pm = MAX517_PM_OPS,
},
.probe = max517_probe,
.remove = max517_remove,
.id_table = max517_id,
};
module_i2c_driver(max517_driver);
MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
MODULE_DESCRIPTION("MAX517/MAX518/MAX519 8-bit DAC");
MODULE_LICENSE("GPL");
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