2012-06-08 10:06:45 -06:00
|
|
|
/*
|
|
|
|
* mcp4725.c - Support for Microchip MCP4725
|
|
|
|
*
|
|
|
|
* Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
|
|
|
|
*
|
|
|
|
* Based on max517 by Roland Stigge <stigge@antcom.de>
|
|
|
|
*
|
|
|
|
* This file is subject to the terms and conditions of version 2 of
|
|
|
|
* the GNU General Public License. See the file COPYING in the main
|
|
|
|
* directory of this archive for more details.
|
|
|
|
*
|
|
|
|
* driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
|
|
|
|
* (7-bit I2C slave address 0x60, the three LSBs can be configured in
|
|
|
|
* hardware)
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/i2c.h>
|
|
|
|
#include <linux/err.h>
|
2013-06-23 15:30:00 -06:00
|
|
|
#include <linux/delay.h>
|
2012-06-08 10:06:45 -06:00
|
|
|
|
|
|
|
#include <linux/iio/iio.h>
|
|
|
|
#include <linux/iio/sysfs.h>
|
|
|
|
|
|
|
|
#include <linux/iio/dac/mcp4725.h>
|
|
|
|
|
|
|
|
#define MCP4725_DRV_NAME "mcp4725"
|
|
|
|
|
|
|
|
struct mcp4725_data {
|
|
|
|
struct i2c_client *client;
|
|
|
|
u16 vref_mv;
|
|
|
|
u16 dac_value;
|
2013-06-23 15:30:00 -06:00
|
|
|
bool powerdown;
|
|
|
|
unsigned powerdown_mode;
|
2012-06-08 10:06:45 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
static int mcp4725_suspend(struct device *dev)
|
|
|
|
{
|
2013-09-18 15:47:00 -06:00
|
|
|
struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
|
|
|
|
to_i2c_client(dev)));
|
2012-06-08 10:06:45 -06:00
|
|
|
u8 outbuf[2];
|
|
|
|
|
2013-06-23 15:30:00 -06:00
|
|
|
outbuf[0] = (data->powerdown_mode + 1) << 4;
|
2012-06-08 10:06:45 -06:00
|
|
|
outbuf[1] = 0;
|
2013-06-23 15:30:00 -06:00
|
|
|
data->powerdown = true;
|
2012-06-08 10:06:45 -06:00
|
|
|
|
2013-09-18 15:47:00 -06:00
|
|
|
return i2c_master_send(data->client, outbuf, 2);
|
2012-06-08 10:06:45 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static int mcp4725_resume(struct device *dev)
|
|
|
|
{
|
2013-09-18 15:47:00 -06:00
|
|
|
struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
|
|
|
|
to_i2c_client(dev)));
|
2012-06-08 10:06:45 -06:00
|
|
|
u8 outbuf[2];
|
|
|
|
|
|
|
|
/* restore previous DAC value */
|
|
|
|
outbuf[0] = (data->dac_value >> 8) & 0xf;
|
|
|
|
outbuf[1] = data->dac_value & 0xff;
|
2013-06-23 15:30:00 -06:00
|
|
|
data->powerdown = false;
|
2012-06-08 10:06:45 -06:00
|
|
|
|
2013-09-18 15:47:00 -06:00
|
|
|
return i2c_master_send(data->client, outbuf, 2);
|
2012-06-08 10:06:45 -06:00
|
|
|
}
|
|
|
|
|
2013-06-23 15:30:00 -06:00
|
|
|
#ifdef CONFIG_PM_SLEEP
|
2012-06-08 10:06:45 -06:00
|
|
|
static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
|
|
|
|
#define MCP4725_PM_OPS (&mcp4725_pm_ops)
|
|
|
|
#else
|
|
|
|
#define MCP4725_PM_OPS NULL
|
|
|
|
#endif
|
|
|
|
|
2013-07-12 13:54:00 -06:00
|
|
|
static ssize_t mcp4725_store_eeprom(struct device *dev,
|
2013-06-23 15:30:00 -06:00
|
|
|
struct device_attribute *attr, const char *buf, size_t len)
|
|
|
|
{
|
|
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
int tries = 20;
|
|
|
|
u8 inoutbuf[3];
|
|
|
|
bool state;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = strtobool(buf, &state);
|
|
|
|
if (ret < 0)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
if (!state)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
inoutbuf[0] = 0x60; /* write EEPROM */
|
|
|
|
inoutbuf[1] = data->dac_value >> 4;
|
|
|
|
inoutbuf[2] = (data->dac_value & 0xf) << 4;
|
|
|
|
|
|
|
|
ret = i2c_master_send(data->client, inoutbuf, 3);
|
|
|
|
if (ret < 0)
|
|
|
|
return ret;
|
|
|
|
else if (ret != 3)
|
|
|
|
return -EIO;
|
|
|
|
|
|
|
|
/* wait for write complete, takes up to 50ms */
|
|
|
|
while (tries--) {
|
|
|
|
msleep(20);
|
|
|
|
ret = i2c_master_recv(data->client, inoutbuf, 3);
|
|
|
|
if (ret < 0)
|
|
|
|
return ret;
|
|
|
|
else if (ret != 3)
|
|
|
|
return -EIO;
|
|
|
|
|
|
|
|
if (inoutbuf[0] & 0x80)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (tries < 0) {
|
|
|
|
dev_err(&data->client->dev,
|
|
|
|
"mcp4725_store_eeprom() failed, incomplete\n");
|
|
|
|
return -EIO;
|
|
|
|
}
|
|
|
|
|
|
|
|
return len;
|
|
|
|
}
|
|
|
|
|
|
|
|
static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
|
|
|
|
|
|
|
|
static struct attribute *mcp4725_attributes[] = {
|
|
|
|
&iio_dev_attr_store_eeprom.dev_attr.attr,
|
|
|
|
NULL,
|
|
|
|
};
|
|
|
|
|
|
|
|
static const struct attribute_group mcp4725_attribute_group = {
|
|
|
|
.attrs = mcp4725_attributes,
|
|
|
|
};
|
|
|
|
|
2013-06-23 15:30:00 -06:00
|
|
|
static const char * const mcp4725_powerdown_modes[] = {
|
|
|
|
"1kohm_to_gnd",
|
|
|
|
"100kohm_to_gnd",
|
|
|
|
"500kohm_to_gnd"
|
|
|
|
};
|
|
|
|
|
|
|
|
static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
|
|
|
|
const struct iio_chan_spec *chan)
|
|
|
|
{
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
|
|
|
|
return data->powerdown_mode;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
|
|
|
|
const struct iio_chan_spec *chan, unsigned mode)
|
|
|
|
{
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
|
|
|
|
data->powerdown_mode = mode;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
|
|
|
|
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
|
|
|
|
{
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
|
|
|
|
return sprintf(buf, "%d\n", data->powerdown);
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
|
|
|
|
uintptr_t private, const struct iio_chan_spec *chan,
|
|
|
|
const char *buf, size_t len)
|
|
|
|
{
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
bool state;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = strtobool(buf, &state);
|
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
if (state)
|
|
|
|
ret = mcp4725_suspend(&data->client->dev);
|
|
|
|
else
|
|
|
|
ret = mcp4725_resume(&data->client->dev);
|
|
|
|
if (ret < 0)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
return len;
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct iio_enum mcp4725_powerdown_mode_enum = {
|
|
|
|
.items = mcp4725_powerdown_modes,
|
|
|
|
.num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
|
|
|
|
.get = mcp4725_get_powerdown_mode,
|
|
|
|
.set = mcp4725_set_powerdown_mode,
|
|
|
|
};
|
|
|
|
|
|
|
|
static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
|
|
|
|
{
|
|
|
|
.name = "powerdown",
|
|
|
|
.read = mcp4725_read_powerdown,
|
|
|
|
.write = mcp4725_write_powerdown,
|
2013-09-08 07:57:00 -06:00
|
|
|
.shared = IIO_SEPARATE,
|
2013-06-23 15:30:00 -06:00
|
|
|
},
|
2013-09-08 07:57:00 -06:00
|
|
|
IIO_ENUM("powerdown_mode", IIO_SEPARATE, &mcp4725_powerdown_mode_enum),
|
2013-06-23 15:30:00 -06:00
|
|
|
IIO_ENUM_AVAILABLE("powerdown_mode", &mcp4725_powerdown_mode_enum),
|
|
|
|
{ },
|
|
|
|
};
|
|
|
|
|
2012-06-08 10:06:45 -06:00
|
|
|
static const struct iio_chan_spec mcp4725_channel = {
|
|
|
|
.type = IIO_VOLTAGE,
|
|
|
|
.indexed = 1,
|
|
|
|
.output = 1,
|
|
|
|
.channel = 0,
|
2013-02-27 12:28:38 -07:00
|
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
|
|
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
|
2013-06-23 15:30:00 -06:00
|
|
|
.ext_info = mcp4725_ext_info,
|
2012-06-08 10:06:45 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
|
|
|
|
{
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
u8 outbuf[2];
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (val >= (1 << 12) || val < 0)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
outbuf[0] = (val >> 8) & 0xf;
|
|
|
|
outbuf[1] = val & 0xff;
|
|
|
|
|
|
|
|
ret = i2c_master_send(data->client, outbuf, 2);
|
|
|
|
if (ret < 0)
|
|
|
|
return ret;
|
|
|
|
else if (ret != 2)
|
|
|
|
return -EIO;
|
|
|
|
else
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int mcp4725_read_raw(struct iio_dev *indio_dev,
|
|
|
|
struct iio_chan_spec const *chan,
|
|
|
|
int *val, int *val2, long mask)
|
|
|
|
{
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
|
|
|
|
switch (mask) {
|
|
|
|
case IIO_CHAN_INFO_RAW:
|
|
|
|
*val = data->dac_value;
|
|
|
|
return IIO_VAL_INT;
|
|
|
|
case IIO_CHAN_INFO_SCALE:
|
2013-09-28 03:31:00 -06:00
|
|
|
*val = data->vref_mv;
|
|
|
|
*val2 = 12;
|
|
|
|
return IIO_VAL_FRACTIONAL_LOG2;
|
2012-06-08 10:06:45 -06:00
|
|
|
}
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int mcp4725_write_raw(struct iio_dev *indio_dev,
|
|
|
|
struct iio_chan_spec const *chan,
|
|
|
|
int val, int val2, long mask)
|
|
|
|
{
|
|
|
|
struct mcp4725_data *data = iio_priv(indio_dev);
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
switch (mask) {
|
|
|
|
case IIO_CHAN_INFO_RAW:
|
|
|
|
ret = mcp4725_set_value(indio_dev, val);
|
|
|
|
data->dac_value = val;
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
ret = -EINVAL;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct iio_info mcp4725_info = {
|
|
|
|
.read_raw = mcp4725_read_raw,
|
|
|
|
.write_raw = mcp4725_write_raw,
|
2013-06-23 15:30:00 -06:00
|
|
|
.attrs = &mcp4725_attribute_group,
|
2012-06-08 10:06:45 -06:00
|
|
|
.driver_module = THIS_MODULE,
|
|
|
|
};
|
|
|
|
|
2012-12-21 14:21:43 -07:00
|
|
|
static int mcp4725_probe(struct i2c_client *client,
|
|
|
|
const struct i2c_device_id *id)
|
2012-06-08 10:06:45 -06:00
|
|
|
{
|
|
|
|
struct mcp4725_data *data;
|
|
|
|
struct iio_dev *indio_dev;
|
|
|
|
struct mcp4725_platform_data *platform_data = client->dev.platform_data;
|
|
|
|
u8 inbuf[3];
|
2013-06-23 15:30:00 -06:00
|
|
|
u8 pd;
|
2012-06-08 10:06:45 -06:00
|
|
|
int err;
|
|
|
|
|
|
|
|
if (!platform_data || !platform_data->vref_mv) {
|
|
|
|
dev_err(&client->dev, "invalid platform data");
|
2013-07-29 16:18:00 -06:00
|
|
|
return -EINVAL;
|
2012-06-08 10:06:45 -06:00
|
|
|
}
|
|
|
|
|
2013-07-29 16:18:00 -06:00
|
|
|
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
|
|
|
|
if (indio_dev == NULL)
|
|
|
|
return -ENOMEM;
|
2012-06-08 10:06:45 -06:00
|
|
|
data = iio_priv(indio_dev);
|
|
|
|
i2c_set_clientdata(client, indio_dev);
|
|
|
|
data->client = client;
|
|
|
|
|
|
|
|
indio_dev->dev.parent = &client->dev;
|
|
|
|
indio_dev->info = &mcp4725_info;
|
|
|
|
indio_dev->channels = &mcp4725_channel;
|
|
|
|
indio_dev->num_channels = 1;
|
|
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
|
|
|
|
|
|
data->vref_mv = platform_data->vref_mv;
|
|
|
|
|
|
|
|
/* read current DAC value */
|
|
|
|
err = i2c_master_recv(client, inbuf, 3);
|
|
|
|
if (err < 0) {
|
|
|
|
dev_err(&client->dev, "failed to read DAC value");
|
2013-07-29 16:18:00 -06:00
|
|
|
return err;
|
2012-06-08 10:06:45 -06:00
|
|
|
}
|
2013-06-23 15:30:00 -06:00
|
|
|
pd = (inbuf[0] >> 1) & 0x3;
|
|
|
|
data->powerdown = pd > 0 ? true : false;
|
|
|
|
data->powerdown_mode = pd ? pd-1 : 2; /* 500kohm_to_gnd */
|
2012-06-08 10:06:45 -06:00
|
|
|
data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
|
|
|
|
|
2013-10-24 05:53:00 -06:00
|
|
|
return iio_device_register(indio_dev);
|
2012-06-08 10:06:45 -06:00
|
|
|
}
|
|
|
|
|
2012-12-21 14:21:43 -07:00
|
|
|
static int mcp4725_remove(struct i2c_client *client)
|
2012-06-08 10:06:45 -06:00
|
|
|
{
|
2013-07-29 16:18:00 -06:00
|
|
|
iio_device_unregister(i2c_get_clientdata(client));
|
2012-06-08 10:06:45 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct i2c_device_id mcp4725_id[] = {
|
|
|
|
{ "mcp4725", 0 },
|
|
|
|
{ }
|
|
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(i2c, mcp4725_id);
|
|
|
|
|
|
|
|
static struct i2c_driver mcp4725_driver = {
|
|
|
|
.driver = {
|
|
|
|
.name = MCP4725_DRV_NAME,
|
|
|
|
.pm = MCP4725_PM_OPS,
|
|
|
|
},
|
|
|
|
.probe = mcp4725_probe,
|
2012-12-21 14:21:43 -07:00
|
|
|
.remove = mcp4725_remove,
|
2012-06-08 10:06:45 -06:00
|
|
|
.id_table = mcp4725_id,
|
|
|
|
};
|
|
|
|
module_i2c_driver(mcp4725_driver);
|
|
|
|
|
|
|
|
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
|
|
|
|
MODULE_DESCRIPTION("MCP4725 12-bit DAC");
|
|
|
|
MODULE_LICENSE("GPL");
|