- 根目录:
- drivers
- iio
- dac
- ad5755.c
/*
* AD5755, AD5755-1, AD5757, AD5735, AD5737 Digital to analog converters driver
*
* Copyright 2012 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/platform_data/ad5755.h>
#define AD5755_NUM_CHANNELS 4
#define AD5755_ADDR(x) ((x) << 16)
#define AD5755_WRITE_REG_DATA(chan) (chan)
#define AD5755_WRITE_REG_GAIN(chan) (0x08 | (chan))
#define AD5755_WRITE_REG_OFFSET(chan) (0x10 | (chan))
#define AD5755_WRITE_REG_CTRL(chan) (0x1c | (chan))
#define AD5755_READ_REG_DATA(chan) (chan)
#define AD5755_READ_REG_CTRL(chan) (0x4 | (chan))
#define AD5755_READ_REG_GAIN(chan) (0x8 | (chan))
#define AD5755_READ_REG_OFFSET(chan) (0xc | (chan))
#define AD5755_READ_REG_CLEAR(chan) (0x10 | (chan))
#define AD5755_READ_REG_SLEW(chan) (0x14 | (chan))
#define AD5755_READ_REG_STATUS 0x18
#define AD5755_READ_REG_MAIN 0x19
#define AD5755_READ_REG_DC_DC 0x1a
#define AD5755_CTRL_REG_SLEW 0x0
#define AD5755_CTRL_REG_MAIN 0x1
#define AD5755_CTRL_REG_DAC 0x2
#define AD5755_CTRL_REG_DC_DC 0x3
#define AD5755_CTRL_REG_SW 0x4
#define AD5755_READ_FLAG 0x800000
#define AD5755_NOOP 0x1CE000
#define AD5755_DAC_INT_EN BIT(8)
#define AD5755_DAC_CLR_EN BIT(7)
#define AD5755_DAC_OUT_EN BIT(6)
#define AD5755_DAC_INT_CURRENT_SENSE_RESISTOR BIT(5)
#define AD5755_DAC_DC_DC_EN BIT(4)
#define AD5755_DAC_VOLTAGE_OVERRANGE_EN BIT(3)
#define AD5755_DC_DC_MAXV 0
#define AD5755_DC_DC_FREQ_SHIFT 2
#define AD5755_DC_DC_PHASE_SHIFT 4
#define AD5755_EXT_DC_DC_COMP_RES BIT(6)
#define AD5755_SLEW_STEP_SIZE_SHIFT 0
#define AD5755_SLEW_RATE_SHIFT 3
#define AD5755_SLEW_ENABLE BIT(12)
/**
* struct ad5755_chip_info - chip specific information
* @channel_template: channel specification
* @calib_shift: shift for the calibration data registers
* @has_voltage_out: whether the chip has voltage outputs
*/
struct ad5755_chip_info {
const struct iio_chan_spec channel_template;
unsigned int calib_shift;
bool has_voltage_out;
};
/**
* struct ad5755_state - driver instance specific data
* @spi: spi device the driver is attached to
* @chip_info: chip model specific constants, available modes etc
* @pwr_down: bitmask which contains hether a channel is powered down or not
* @ctrl: software shadow of the channel ctrl registers
* @channels: iio channel spec for the device
* @data: spi transfer buffers
*/
struct ad5755_state {
struct spi_device *spi;
const struct ad5755_chip_info *chip_info;
unsigned int pwr_down;
unsigned int ctrl[AD5755_NUM_CHANNELS];
struct iio_chan_spec channels[AD5755_NUM_CHANNELS];
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
union {
u32 d32;
u8 d8[4];
} data[2] ____cacheline_aligned;
};
enum ad5755_type {
ID_AD5755,
ID_AD5757,
ID_AD5735,
ID_AD5737,
};
static int ad5755_write_unlocked(struct iio_dev *indio_dev,
unsigned int reg, unsigned int val)
{
struct ad5755_state *st = iio_priv(indio_dev);
st->data[0].d32 = cpu_to_be32((reg << 16) | val);
return spi_write(st->spi, &st->data[0].d8[1], 3);
}
static int ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev,
unsigned int channel, unsigned int reg, unsigned int val)
{
return ad5755_write_unlocked(indio_dev,
AD5755_WRITE_REG_CTRL(channel), (reg << 13) | val);
}
static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
unsigned int val)
{
int ret;
mutex_lock(&indio_dev->mlock);
ret = ad5755_write_unlocked(indio_dev, reg, val);
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel,
unsigned int reg, unsigned int val)
{
int ret;
mutex_lock(&indio_dev->mlock);
ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val);
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
{
struct ad5755_state *st = iio_priv(indio_dev);
int ret;
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[1].d8[1],
.len = 3,
},
};
mutex_lock(&indio_dev->mlock);
st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16));
st->data[1].d32 = cpu_to_be32(AD5755_NOOP);
ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
if (ret >= 0)
ret = be32_to_cpu(st->data[1].d32) & 0xffff;
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5755_update_dac_ctrl(struct iio_dev *indio_dev,
unsigned int channel, unsigned int set, unsigned int clr)
{
struct ad5755_state *st = iio_priv(indio_dev);
int ret;
st->ctrl[channel] |= set;
st->ctrl[channel] &= ~clr;
ret = ad5755_write_ctrl_unlocked(indio_dev, channel,
AD5755_CTRL_REG_DAC, st->ctrl[channel]);
return ret;
}
static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
unsigned int channel, bool pwr_down)
{
struct ad5755_state *st = iio_priv(indio_dev);
unsigned int mask = BIT(channel);
mutex_lock(&indio_dev->mlock);
if ((bool)(st->pwr_down & mask) == pwr_down)
goto out_unlock;
if (!pwr_down) {
st->pwr_down &= ~mask;
ad5755_update_dac_ctrl(indio_dev, channel,
AD5755_DAC_INT_EN | AD5755_DAC_DC_DC_EN, 0);
udelay(200);
ad5755_update_dac_ctrl(indio_dev, channel,
AD5755_DAC_OUT_EN, 0);
} else {
st->pwr_down |= mask;
ad5755_update_dac_ctrl(indio_dev, channel,
0, AD5755_DAC_INT_EN | AD5755_DAC_OUT_EN |
AD5755_DAC_DC_DC_EN);
}
out_unlock:
mutex_unlock(&indio_dev->mlock);
return 0;
}
static const int ad5755_min_max_table[][2] = {
[AD5755_MODE_VOLTAGE_0V_5V] = { 0, 5000 },
[AD5755_MODE_VOLTAGE_0V_10V] = { 0, 10000 },
[AD5755_MODE_VOLTAGE_PLUSMINUS_5V] = { -5000, 5000 },
[AD5755_MODE_VOLTAGE_PLUSMINUS_10V] = { -10000, 10000 },
[AD5755_MODE_CURRENT_4mA_20mA] = { 4, 20 },
[AD5755_MODE_CURRENT_0mA_20mA] = { 0, 20 },
[AD5755_MODE_CURRENT_0mA_24mA] = { 0, 24 },
};
static void ad5755_get_min_max(struct ad5755_state *st,
struct iio_chan_spec const *chan, int *min, int *max)
{
enum ad5755_mode mode = st->ctrl[chan->channel] & 7;
*min = ad5755_min_max_table[mode][0];
*max = ad5755_min_max_table[mode][1];
}
static inline int ad5755_get_offset(struct ad5755_state *st,
struct iio_chan_spec const *chan)
{
int min, max;
ad5755_get_min_max(st, chan, &min, &max);
return (min * (1 << chan->scan_type.realbits)) / (max - min);
}
static inline int ad5755_get_scale(struct ad5755_state *st,
struct iio_chan_spec const *chan)
{
int min, max;
ad5755_get_min_max(st, chan, &min, &max);
return ((max - min) * 1000000000ULL) >> chan->scan_type.realbits;
}
static int ad5755_chan_reg_info(struct ad5755_state *st,
struct iio_chan_spec const *chan, long info, bool write,
unsigned int *reg, unsigned int *shift, unsigned int *offset)
{
switch (info) {
case IIO_CHAN_INFO_RAW:
if (write)
*reg = AD5755_WRITE_REG_DATA(chan->address);
else
*reg = AD5755_READ_REG_DATA(chan->address);
*shift = chan->scan_type.shift;
*offset = 0;
break;
case IIO_CHAN_INFO_CALIBBIAS:
if (write)
*reg = AD5755_WRITE_REG_OFFSET(chan->address);
else
*reg = AD5755_READ_REG_OFFSET(chan->address);
*shift = st->chip_info->calib_shift;
*offset = 32768;
break;
case IIO_CHAN_INFO_CALIBSCALE:
if (write)
*reg = AD5755_WRITE_REG_GAIN(chan->address);
else
*reg = AD5755_READ_REG_GAIN(chan->address);
*shift = st->chip_info->calib_shift;
*offset = 0;
break;
default:
return -EINVAL;
}
return 0;
}
static int ad5755_read_raw(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, int *val, int *val2, long info)
{
struct ad5755_state *st = iio_priv(indio_dev);
unsigned int reg, shift, offset;
int ret;
switch (info) {
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = ad5755_get_scale(st, chan);
return IIO_VAL_INT_PLUS_NANO;
case IIO_CHAN_INFO_OFFSET:
*val = ad5755_get_offset(st, chan);
return IIO_VAL_INT;
default:
ret = ad5755_chan_reg_info(st, chan, info, false,
®, &shift, &offset);
if (ret)
return ret;
ret = ad5755_read(indio_dev, reg);
if (ret < 0)
return ret;
*val = (ret - offset) >> shift;
return IIO_VAL_INT;
}
return -EINVAL;
}
static int ad5755_write_raw(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, int val, int val2, long info)
{
struct ad5755_state *st = iio_priv(indio_dev);
unsigned int shift, reg, offset;
int ret;
ret = ad5755_chan_reg_info(st, chan, info, true,
®, &shift, &offset);
if (ret)
return ret;
val <<= shift;
val += offset;
if (val < 0 || val > 0xffff)
return -EINVAL;
return ad5755_write(indio_dev, reg, val);
}
static ssize_t ad5755_read_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
const struct iio_chan_spec *chan, char *buf)
{
struct ad5755_state *st = iio_priv(indio_dev);
return sprintf(buf, "%d\n",
(bool)(st->pwr_down & (1 << chan->channel)));
}
static ssize_t ad5755_write_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
struct iio_chan_spec const *chan, const char *buf, size_t len)
{
bool pwr_down;
int ret;
ret = strtobool(buf, &pwr_down);
if (ret)
return ret;
ret = ad5755_set_channel_pwr_down(indio_dev, chan->channel, pwr_down);
return ret ? ret : len;
}
static const struct iio_info ad5755_info = {
.read_raw = ad5755_read_raw,
.write_raw = ad5755_write_raw,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec_ext_info ad5755_ext_info[] = {
{
.name = "powerdown",
.read = ad5755_read_powerdown,
.write = ad5755_write_powerdown,
},
{ },
};
#define AD5755_CHANNEL(_bits) { \
.indexed = 1, \
.output = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_CALIBSCALE) | \
BIT(IIO_CHAN_INFO_CALIBBIAS), \
.scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)), \
.ext_info = ad5755_ext_info, \
}
static const struct ad5755_chip_info ad5755_chip_info_tbl[] = {
[ID_AD5735] = {
.channel_template = AD5755_CHANNEL(14),
.has_voltage_out = true,
.calib_shift = 4,
},
[ID_AD5737] = {
.channel_template = AD5755_CHANNEL(14),
.has_voltage_out = false,
.calib_shift = 4,
},
[ID_AD5755] = {
.channel_template = AD5755_CHANNEL(16),
.has_voltage_out = true,
.calib_shift = 0,
},
[ID_AD5757] = {
.channel_template = AD5755_CHANNEL(16),
.has_voltage_out = false,
.calib_shift = 0,
},
};
static bool ad5755_is_valid_mode(struct ad5755_state *st, enum ad5755_mode mode)
{
switch (mode) {
case AD5755_MODE_VOLTAGE_0V_5V:
case AD5755_MODE_VOLTAGE_0V_10V:
case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
return st->chip_info->has_voltage_out;
case AD5755_MODE_CURRENT_4mA_20mA:
case AD5755_MODE_CURRENT_0mA_20mA:
case AD5755_MODE_CURRENT_0mA_24mA:
return true;
default:
return false;
}
}
static int ad5755_setup_pdata(struct iio_dev *indio_dev,
const struct ad5755_platform_data *pdata)
{
struct ad5755_state *st = iio_priv(indio_dev);
unsigned int val;
unsigned int i;
int ret;
if (pdata->dc_dc_phase > AD5755_DC_DC_PHASE_90_DEGREE ||
pdata->dc_dc_freq > AD5755_DC_DC_FREQ_650kHZ ||
pdata->dc_dc_maxv > AD5755_DC_DC_MAXV_29V5)
return -EINVAL;
val = pdata->dc_dc_maxv << AD5755_DC_DC_MAXV;
val |= pdata->dc_dc_freq << AD5755_DC_DC_FREQ_SHIFT;
val |= pdata->dc_dc_phase << AD5755_DC_DC_PHASE_SHIFT;
if (pdata->ext_dc_dc_compenstation_resistor)
val |= AD5755_EXT_DC_DC_COMP_RES;
ret = ad5755_write_ctrl(indio_dev, 0, AD5755_CTRL_REG_DC_DC, val);
if (ret < 0)
return ret;
for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
val = pdata->dac[i].slew.step_size <<
AD5755_SLEW_STEP_SIZE_SHIFT;
val |= pdata->dac[i].slew.rate <<
AD5755_SLEW_RATE_SHIFT;
if (pdata->dac[i].slew.enable)
val |= AD5755_SLEW_ENABLE;
ret = ad5755_write_ctrl(indio_dev, i,
AD5755_CTRL_REG_SLEW, val);
if (ret < 0)
return ret;
}
for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
if (!ad5755_is_valid_mode(st, pdata->dac[i].mode))
return -EINVAL;
val = 0;
if (!pdata->dac[i].ext_current_sense_resistor)
val |= AD5755_DAC_INT_CURRENT_SENSE_RESISTOR;
if (pdata->dac[i].enable_voltage_overrange)
val |= AD5755_DAC_VOLTAGE_OVERRANGE_EN;
val |= pdata->dac[i].mode;
ret = ad5755_update_dac_ctrl(indio_dev, i, val, 0);
if (ret < 0)
return ret;
}
return 0;
}
static bool ad5755_is_voltage_mode(enum ad5755_mode mode)
{
switch (mode) {
case AD5755_MODE_VOLTAGE_0V_5V:
case AD5755_MODE_VOLTAGE_0V_10V:
case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
return true;
default:
return false;
}
}
static int ad5755_init_channels(struct iio_dev *indio_dev,
const struct ad5755_platform_data *pdata)
{
struct ad5755_state *st = iio_priv(indio_dev);
struct iio_chan_spec *channels = st->channels;
unsigned int i;
for (i = 0; i < AD5755_NUM_CHANNELS; ++i) {
channels[i] = st->chip_info->channel_template;
channels[i].channel = i;
channels[i].address = i;
if (pdata && ad5755_is_voltage_mode(pdata->dac[i].mode))
channels[i].type = IIO_VOLTAGE;
else
channels[i].type = IIO_CURRENT;
}
indio_dev->channels = channels;
return 0;
}
#define AD5755_DEFAULT_DAC_PDATA { \
.mode = AD5755_MODE_CURRENT_4mA_20mA, \
.ext_current_sense_resistor = true, \
.enable_voltage_overrange = false, \
.slew = { \
.enable = false, \
.rate = AD5755_SLEW_RATE_64k, \
.step_size = AD5755_SLEW_STEP_SIZE_1, \
}, \
}
static const struct ad5755_platform_data ad5755_default_pdata = {
.ext_dc_dc_compenstation_resistor = false,
.dc_dc_phase = AD5755_DC_DC_PHASE_ALL_SAME_EDGE,
.dc_dc_freq = AD5755_DC_DC_FREQ_410kHZ,
.dc_dc_maxv = AD5755_DC_DC_MAXV_23V,
.dac = {
[0] = AD5755_DEFAULT_DAC_PDATA,
[1] = AD5755_DEFAULT_DAC_PDATA,
[2] = AD5755_DEFAULT_DAC_PDATA,
[3] = AD5755_DEFAULT_DAC_PDATA,
},
};
static int ad5755_probe(struct spi_device *spi)
{
enum ad5755_type type = spi_get_device_id(spi)->driver_data;
const struct ad5755_platform_data *pdata = dev_get_platdata(&spi->dev);
struct iio_dev *indio_dev;
struct ad5755_state *st;
int ret;
indio_dev = iio_device_alloc(sizeof(*st));
if (indio_dev == NULL) {
dev_err(&spi->dev, "Failed to allocate iio device\n");
return -ENOMEM;
}
st = iio_priv(indio_dev);
spi_set_drvdata(spi, indio_dev);
st->chip_info = &ad5755_chip_info_tbl[type];
st->spi = spi;
st->pwr_down = 0xf;
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad5755_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->num_channels = AD5755_NUM_CHANNELS;
if (!pdata)
pdata = &ad5755_default_pdata;
ret = ad5755_init_channels(indio_dev, pdata);
if (ret)
goto error_free;
ret = ad5755_setup_pdata(indio_dev, pdata);
if (ret)
goto error_free;
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&spi->dev, "Failed to register iio device: %d\n", ret);
goto error_free;
}
return 0;
error_free:
iio_device_free(indio_dev);
return ret;
}
static int ad5755_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
iio_device_unregister(indio_dev);
iio_device_free(indio_dev);
return 0;
}
static const struct spi_device_id ad5755_id[] = {
{ "ad5755", ID_AD5755 },
{ "ad5755-1", ID_AD5755 },
{ "ad5757", ID_AD5757 },
{ "ad5735", ID_AD5735 },
{ "ad5737", ID_AD5737 },
{}
};
MODULE_DEVICE_TABLE(spi, ad5755_id);
static struct spi_driver ad5755_driver = {
.driver = {
.name = "ad5755",
.owner = THIS_MODULE,
},
.probe = ad5755_probe,
.remove = ad5755_remove,
.id_table = ad5755_id,
};
module_spi_driver(ad5755_driver);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Analog Devices AD5755/55-1/57/35/37 DAC");
MODULE_LICENSE("GPL v2");