- 根目录:
- drivers
- iio
- dac
- ad5686.c
/*
* AD5686R, AD5685R, AD5684R Digital to analog converters driver
*
* Copyright 2011 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/module.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/iio/iio.h>
#include <linux/iio/sysfs.h>
#define AD5686_DAC_CHANNELS 4
#define AD5686_ADDR(x) ((x) << 16)
#define AD5686_CMD(x) ((x) << 20)
#define AD5686_ADDR_DAC(chan) (0x1 << (chan))
#define AD5686_ADDR_ALL_DAC 0xF
#define AD5686_CMD_NOOP 0x0
#define AD5686_CMD_WRITE_INPUT_N 0x1
#define AD5686_CMD_UPDATE_DAC_N 0x2
#define AD5686_CMD_WRITE_INPUT_N_UPDATE_N 0x3
#define AD5686_CMD_POWERDOWN_DAC 0x4
#define AD5686_CMD_LDAC_MASK 0x5
#define AD5686_CMD_RESET 0x6
#define AD5686_CMD_INTERNAL_REFER_SETUP 0x7
#define AD5686_CMD_DAISY_CHAIN_ENABLE 0x8
#define AD5686_CMD_READBACK_ENABLE 0x9
#define AD5686_LDAC_PWRDN_NONE 0x0
#define AD5686_LDAC_PWRDN_1K 0x1
#define AD5686_LDAC_PWRDN_100K 0x2
#define AD5686_LDAC_PWRDN_3STATE 0x3
/**
* struct ad5686_chip_info - chip specific information
* @int_vref_mv: AD5620/40/60: the internal reference voltage
* @channel: channel specification
*/
struct ad5686_chip_info {
u16 int_vref_mv;
struct iio_chan_spec channel[AD5686_DAC_CHANNELS];
};
/**
* struct ad5446_state - driver instance specific data
* @spi: spi_device
* @chip_info: chip model specific constants, available modes etc
* @reg: supply regulator
* @vref_mv: actual reference voltage used
* @pwr_down_mask: power down mask
* @pwr_down_mode: current power down mode
* @data: spi transfer buffers
*/
struct ad5686_state {
struct spi_device *spi;
const struct ad5686_chip_info *chip_info;
struct regulator *reg;
unsigned short vref_mv;
unsigned pwr_down_mask;
unsigned pwr_down_mode;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
union {
__be32 d32;
u8 d8[4];
} data[3] ____cacheline_aligned;
};
/**
* ad5686_supported_device_ids:
*/
enum ad5686_supported_device_ids {
ID_AD5684,
ID_AD5685,
ID_AD5686,
};
static int ad5686_spi_write(struct ad5686_state *st,
u8 cmd, u8 addr, u16 val, u8 shift)
{
val <<= shift;
st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
AD5686_ADDR(addr) |
val);
return spi_write(st->spi, &st->data[0].d8[1], 3);
}
static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
{
struct spi_transfer t[] = {
{
.tx_buf = &st->data[0].d8[1],
.len = 3,
.cs_change = 1,
}, {
.tx_buf = &st->data[1].d8[1],
.rx_buf = &st->data[2].d8[1],
.len = 3,
},
};
int ret;
st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_READBACK_ENABLE) |
AD5686_ADDR(addr));
st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));
ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
if (ret < 0)
return ret;
return be32_to_cpu(st->data[2].d32);
}
static const char * const ad5686_powerdown_modes[] = {
"1kohm_to_gnd",
"100kohm_to_gnd",
"three_state"
};
static int ad5686_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ad5686_state *st = iio_priv(indio_dev);
return ((st->pwr_down_mode >> (chan->channel * 2)) & 0x3) - 1;
}
static int ad5686_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int mode)
{
struct ad5686_state *st = iio_priv(indio_dev);
st->pwr_down_mode &= ~(0x3 << (chan->channel * 2));
st->pwr_down_mode |= ((mode + 1) << (chan->channel * 2));
return 0;
}
static const struct iio_enum ad5686_powerdown_mode_enum = {
.items = ad5686_powerdown_modes,
.num_items = ARRAY_SIZE(ad5686_powerdown_modes),
.get = ad5686_get_powerdown_mode,
.set = ad5686_set_powerdown_mode,
};
static ssize_t ad5686_read_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
struct ad5686_state *st = iio_priv(indio_dev);
return sprintf(buf, "%d\n", !!(st->pwr_down_mask &
(0x3 << (chan->channel * 2))));
}
static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
size_t len)
{
bool readin;
int ret;
struct ad5686_state *st = iio_priv(indio_dev);
ret = strtobool(buf, &readin);
if (ret)
return ret;
if (readin)
st->pwr_down_mask |= (0x3 << (chan->channel * 2));
else
st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));
ret = ad5686_spi_write(st, AD5686_CMD_POWERDOWN_DAC, 0,
st->pwr_down_mask & st->pwr_down_mode, 0);
return ret ? ret : len;
}
static int ad5686_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad5686_state *st = iio_priv(indio_dev);
int ret;
switch (m) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&indio_dev->mlock);
ret = ad5686_spi_read(st, chan->address);
mutex_unlock(&indio_dev->mlock);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = st->vref_mv;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
static int ad5686_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad5686_state *st = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val > (1 << chan->scan_type.realbits) || val < 0)
return -EINVAL;
mutex_lock(&indio_dev->mlock);
ret = ad5686_spi_write(st,
AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
chan->address,
val,
chan->scan_type.shift);
mutex_unlock(&indio_dev->mlock);
break;
default:
ret = -EINVAL;
}
return ret;
}
static const struct iio_info ad5686_info = {
.read_raw = ad5686_read_raw,
.write_raw = ad5686_write_raw,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
{
.name = "powerdown",
.read = ad5686_read_dac_powerdown,
.write = ad5686_write_dac_powerdown,
.shared = IIO_SEPARATE,
},
IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5686_powerdown_mode_enum),
IIO_ENUM_AVAILABLE("powerdown_mode", &ad5686_powerdown_mode_enum),
{ },
};
#define AD5868_CHANNEL(chan, bits, _shift) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = chan, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
.address = AD5686_ADDR_DAC(chan), \
.scan_type = { \
.sign = 'u', \
.realbits = (bits), \
.storagebits = 16, \
.shift = (_shift), \
}, \
.ext_info = ad5686_ext_info, \
}
static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
[ID_AD5684] = {
.channel[0] = AD5868_CHANNEL(0, 12, 4),
.channel[1] = AD5868_CHANNEL(1, 12, 4),
.channel[2] = AD5868_CHANNEL(2, 12, 4),
.channel[3] = AD5868_CHANNEL(3, 12, 4),
.int_vref_mv = 2500,
},
[ID_AD5685] = {
.channel[0] = AD5868_CHANNEL(0, 14, 2),
.channel[1] = AD5868_CHANNEL(1, 14, 2),
.channel[2] = AD5868_CHANNEL(2, 14, 2),
.channel[3] = AD5868_CHANNEL(3, 14, 2),
.int_vref_mv = 2500,
},
[ID_AD5686] = {
.channel[0] = AD5868_CHANNEL(0, 16, 0),
.channel[1] = AD5868_CHANNEL(1, 16, 0),
.channel[2] = AD5868_CHANNEL(2, 16, 0),
.channel[3] = AD5868_CHANNEL(3, 16, 0),
.int_vref_mv = 2500,
},
};
static int ad5686_probe(struct spi_device *spi)
{
struct ad5686_state *st;
struct iio_dev *indio_dev;
int ret, voltage_uv = 0;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
spi_set_drvdata(spi, indio_dev);
st->reg = devm_regulator_get_optional(&spi->dev, "vcc");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret)
return ret;
ret = regulator_get_voltage(st->reg);
if (ret < 0)
goto error_disable_reg;
voltage_uv = ret;
}
st->chip_info =
&ad5686_chip_info_tbl[spi_get_device_id(spi)->driver_data];
if (voltage_uv)
st->vref_mv = voltage_uv / 1000;
else
st->vref_mv = st->chip_info->int_vref_mv;
st->spi = spi;
/* Set all the power down mode for all channels to 1K pulldown */
st->pwr_down_mode = 0x55;
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad5686_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = st->chip_info->channel;
indio_dev->num_channels = AD5686_DAC_CHANNELS;
ret = ad5686_spi_write(st, AD5686_CMD_INTERNAL_REFER_SETUP, 0,
!!voltage_uv, 0);
if (ret)
goto error_disable_reg;
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg;
return 0;
error_disable_reg:
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
return ret;
}
static int ad5686_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad5686_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
return 0;
}
static const struct spi_device_id ad5686_id[] = {
{"ad5684", ID_AD5684},
{"ad5685", ID_AD5685},
{"ad5686", ID_AD5686},
{}
};
MODULE_DEVICE_TABLE(spi, ad5686_id);
static struct spi_driver ad5686_driver = {
.driver = {
.name = "ad5686",
.owner = THIS_MODULE,
},
.probe = ad5686_probe,
.remove = ad5686_remove,
.id_table = ad5686_id,
};
module_spi_driver(ad5686_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD5686/85/84 DAC");
MODULE_LICENSE("GPL v2");