- 根目录:
- drivers
- staging
- iio
- dac
- ad5791.c
/*
* AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog
* Converter
*
* Copyright 2011 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
#include "../iio.h"
#include "../sysfs.h"
#include "dac.h"
#include "ad5791.h"
static int ad5791_spi_write(struct spi_device *spi, u8 addr, u32 val)
{
union {
u32 d32;
u8 d8[4];
} data;
data.d32 = cpu_to_be32(AD5791_CMD_WRITE |
AD5791_ADDR(addr) |
(val & AD5791_DAC_MASK));
return spi_write(spi, &data.d8[1], 3);
}
static int ad5791_spi_read(struct spi_device *spi, u8 addr, u32 *val)
{
union {
u32 d32;
u8 d8[4];
} data[3];
int ret;
struct spi_message msg;
struct spi_transfer xfers[] = {
{
.tx_buf = &data[0].d8[1],
.bits_per_word = 8,
.len = 3,
.cs_change = 1,
}, {
.tx_buf = &data[1].d8[1],
.rx_buf = &data[2].d8[1],
.bits_per_word = 8,
.len = 3,
},
};
data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
AD5791_ADDR(addr));
data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
spi_message_init(&msg);
spi_message_add_tail(&xfers[0], &msg);
spi_message_add_tail(&xfers[1], &msg);
ret = spi_sync(spi, &msg);
*val = be32_to_cpu(data[2].d32);
return ret;
}
#define AD5791_CHAN(bits, shift) { \
.type = IIO_VOLTAGE, \
.output = 1, \
.indexed = 1, \
.address = AD5791_ADDR_DAC0, \
.channel = 0, \
.info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT | \
IIO_CHAN_INFO_OFFSET_SHARED_BIT, \
.scan_type = IIO_ST('u', bits, 24, shift) \
}
static const struct iio_chan_spec ad5791_channels[] = {
[ID_AD5760] = AD5791_CHAN(16, 4),
[ID_AD5780] = AD5791_CHAN(18, 2),
[ID_AD5781] = AD5791_CHAN(18, 2),
[ID_AD5791] = AD5791_CHAN(20, 0)
};
static ssize_t ad5791_read_powerdown_mode(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad5791_state *st = iio_priv(indio_dev);
const char mode[][14] = {"6kohm_to_gnd", "three_state"};
return sprintf(buf, "%s\n", mode[st->pwr_down_mode]);
}
static ssize_t ad5791_write_powerdown_mode(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad5791_state *st = iio_priv(indio_dev);
int ret;
if (sysfs_streq(buf, "6kohm_to_gnd"))
st->pwr_down_mode = AD5791_DAC_PWRDN_6K;
else if (sysfs_streq(buf, "three_state"))
st->pwr_down_mode = AD5791_DAC_PWRDN_3STATE;
else
ret = -EINVAL;
return ret ? ret : len;
}
static ssize_t ad5791_read_dac_powerdown(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad5791_state *st = iio_priv(indio_dev);
return sprintf(buf, "%d\n", st->pwr_down);
}
static ssize_t ad5791_write_dac_powerdown(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
long readin;
int ret;
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad5791_state *st = iio_priv(indio_dev);
ret = strict_strtol(buf, 10, &readin);
if (ret)
return ret;
if (readin == 0) {
st->pwr_down = false;
st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
} else if (readin == 1) {
st->pwr_down = true;
if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K)
st->ctrl |= AD5791_CTRL_OPGND;
else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE)
st->ctrl |= AD5791_CTRL_DACTRI;
} else
ret = -EINVAL;
ret = ad5791_spi_write(st->spi, AD5791_ADDR_CTRL, st->ctrl);
return ret ? ret : len;
}
static IIO_DEVICE_ATTR(out_voltage_powerdown_mode, S_IRUGO |
S_IWUSR, ad5791_read_powerdown_mode,
ad5791_write_powerdown_mode, 0);
static IIO_CONST_ATTR(out_voltage_powerdown_mode_available,
"6kohm_to_gnd three_state");
#define IIO_DEV_ATTR_DAC_POWERDOWN(_num, _show, _store, _addr) \
IIO_DEVICE_ATTR(out_voltage##_num##_powerdown, \
S_IRUGO | S_IWUSR, _show, _store, _addr)
static IIO_DEV_ATTR_DAC_POWERDOWN(0, ad5791_read_dac_powerdown,
ad5791_write_dac_powerdown, 0);
static struct attribute *ad5791_attributes[] = {
&iio_dev_attr_out_voltage0_powerdown.dev_attr.attr,
&iio_dev_attr_out_voltage_powerdown_mode.dev_attr.attr,
&iio_const_attr_out_voltage_powerdown_mode_available.dev_attr.attr,
NULL,
};
static const struct attribute_group ad5791_attribute_group = {
.attrs = ad5791_attributes,
};
static int ad5791_get_lin_comp(unsigned int span)
{
if (span <= 10000)
return AD5791_LINCOMP_0_10;
else if (span <= 12000)
return AD5791_LINCOMP_10_12;
else if (span <= 16000)
return AD5791_LINCOMP_12_16;
else if (span <= 19000)
return AD5791_LINCOMP_16_19;
else
return AD5791_LINCOMP_19_20;
}
static int ad5780_get_lin_comp(unsigned int span)
{
if (span <= 10000)
return AD5780_LINCOMP_0_10;
else
return AD5780_LINCOMP_10_20;
}
static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
[ID_AD5760] = {
.get_lin_comp = ad5780_get_lin_comp,
},
[ID_AD5780] = {
.get_lin_comp = ad5780_get_lin_comp,
},
[ID_AD5781] = {
.get_lin_comp = ad5791_get_lin_comp,
},
[ID_AD5791] = {
.get_lin_comp = ad5791_get_lin_comp,
},
};
static int ad5791_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad5791_state *st = iio_priv(indio_dev);
u64 val64;
int ret;
switch (m) {
case 0:
ret = ad5791_spi_read(st->spi, chan->address, val);
if (ret)
return ret;
*val &= AD5791_DAC_MASK;
*val >>= chan->scan_type.shift;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = (((u64)st->vref_mv) * 1000000ULL) >> chan->scan_type.realbits;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_OFFSET:
val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
do_div(val64, st->vref_mv);
*val = -val64;
return IIO_VAL_INT;
default:
return -EINVAL;
}
};
static int ad5791_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad5791_state *st = iio_priv(indio_dev);
switch (mask) {
case 0:
val &= AD5791_RES_MASK(chan->scan_type.realbits);
val <<= chan->scan_type.shift;
return ad5791_spi_write(st->spi, chan->address, val);
default:
return -EINVAL;
}
}
static const struct iio_info ad5791_info = {
.read_raw = &ad5791_read_raw,
.write_raw = &ad5791_write_raw,
.attrs = &ad5791_attribute_group,
.driver_module = THIS_MODULE,
};
static int __devinit ad5791_probe(struct spi_device *spi)
{
struct ad5791_platform_data *pdata = spi->dev.platform_data;
struct iio_dev *indio_dev;
struct ad5791_state *st;
int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
indio_dev = iio_allocate_device(sizeof(*st));
if (indio_dev == NULL) {
ret = -ENOMEM;
goto error_ret;
}
st = iio_priv(indio_dev);
st->reg_vdd = regulator_get(&spi->dev, "vdd");
if (!IS_ERR(st->reg_vdd)) {
ret = regulator_enable(st->reg_vdd);
if (ret)
goto error_put_reg_pos;
pos_voltage_uv = regulator_get_voltage(st->reg_vdd);
}
st->reg_vss = regulator_get(&spi->dev, "vss");
if (!IS_ERR(st->reg_vss)) {
ret = regulator_enable(st->reg_vss);
if (ret)
goto error_put_reg_neg;
neg_voltage_uv = regulator_get_voltage(st->reg_vss);
}
st->pwr_down = true;
st->spi = spi;
if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
st->vref_neg_mv = neg_voltage_uv / 1000;
} else if (pdata) {
st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv;
st->vref_neg_mv = pdata->vref_neg_mv;
} else {
dev_warn(&spi->dev, "reference voltage unspecified\n");
}
ret = ad5791_spi_write(spi, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
if (ret)
goto error_disable_reg_neg;
st->chip_info = &ad5791_chip_info_tbl[spi_get_device_id(spi)
->driver_data];
st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
| ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
AD5791_CTRL_BIN2SC;
ret = ad5791_spi_write(spi, AD5791_ADDR_CTRL, st->ctrl |
AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
if (ret)
goto error_disable_reg_neg;
spi_set_drvdata(spi, indio_dev);
indio_dev->dev.parent = &spi->dev;
indio_dev->info = &ad5791_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels
= &ad5791_channels[spi_get_device_id(spi)->driver_data];
indio_dev->num_channels = 1;
indio_dev->name = spi_get_device_id(st->spi)->name;
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg_neg;
return 0;
error_disable_reg_neg:
if (!IS_ERR(st->reg_vss))
regulator_disable(st->reg_vss);
error_put_reg_neg:
if (!IS_ERR(st->reg_vss))
regulator_put(st->reg_vss);
if (!IS_ERR(st->reg_vdd))
regulator_disable(st->reg_vdd);
error_put_reg_pos:
if (!IS_ERR(st->reg_vdd))
regulator_put(st->reg_vdd);
iio_free_device(indio_dev);
error_ret:
return ret;
}
static int __devexit ad5791_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad5791_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
if (!IS_ERR(st->reg_vdd)) {
regulator_disable(st->reg_vdd);
regulator_put(st->reg_vdd);
}
if (!IS_ERR(st->reg_vss)) {
regulator_disable(st->reg_vss);
regulator_put(st->reg_vss);
}
iio_free_device(indio_dev);
return 0;
}
static const struct spi_device_id ad5791_id[] = {
{"ad5760", ID_AD5760},
{"ad5780", ID_AD5780},
{"ad5781", ID_AD5781},
{"ad5790", ID_AD5791},
{"ad5791", ID_AD5791},
{}
};
MODULE_DEVICE_TABLE(spi, ad5791_id);
static struct spi_driver ad5791_driver = {
.driver = {
.name = "ad5791",
.owner = THIS_MODULE,
},
.probe = ad5791_probe,
.remove = __devexit_p(ad5791_remove),
.id_table = ad5791_id,
};
module_spi_driver(ad5791_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
MODULE_LICENSE("GPL v2");