linux/drivers/iio/dac/ad5504.c

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/*
* AD5504, AD5501 High Voltage 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 <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/dac/ad5504.h>
#define AD5505_BITS 12
#define AD5504_RES_MASK ((1 << (AD5505_BITS)) - 1)
#define AD5504_CMD_READ (1 << 15)
#define AD5504_CMD_WRITE (0 << 15)
#define AD5504_ADDR(addr) ((addr) << 12)
/* Registers */
#define AD5504_ADDR_NOOP 0
#define AD5504_ADDR_DAC(x) ((x) + 1)
#define AD5504_ADDR_ALL_DAC 5
#define AD5504_ADDR_CTRL 7
/* Control Register */
#define AD5504_DAC_PWR(ch) ((ch) << 2)
#define AD5504_DAC_PWRDWN_MODE(mode) ((mode) << 6)
#define AD5504_DAC_PWRDN_20K 0
#define AD5504_DAC_PWRDN_3STATE 1
/**
* struct ad5446_state - driver instance specific data
* @us: spi_device
* @reg: supply regulator
* @vref_mv: actual reference voltage used
* @pwr_down_mask power down mask
* @pwr_down_mode current power down mode
*/
struct ad5504_state {
struct spi_device *spi;
struct regulator *reg;
unsigned short vref_mv;
unsigned pwr_down_mask;
unsigned pwr_down_mode;
};
/**
* ad5504_supported_device_ids:
*/
enum ad5504_supported_device_ids {
ID_AD5504,
ID_AD5501,
};
static int ad5504_spi_write(struct spi_device *spi, u8 addr, u16 val)
{
u16 tmp = cpu_to_be16(AD5504_CMD_WRITE |
AD5504_ADDR(addr) |
(val & AD5504_RES_MASK));
return spi_write(spi, (u8 *)&tmp, 2);
}
static int ad5504_spi_read(struct spi_device *spi, u8 addr)
{
u16 tmp = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
u16 val;
int ret;
struct spi_transfer t = {
.tx_buf = &tmp,
.rx_buf = &val,
.len = 2,
};
ret = spi_sync_transfer(spi, &t, 1);
if (ret < 0)
return ret;
return be16_to_cpu(val) & AD5504_RES_MASK;
}
static int ad5504_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad5504_state *st = iio_priv(indio_dev);
unsigned long scale_uv;
int ret;
switch (m) {
case IIO_CHAN_INFO_RAW:
ret = ad5504_spi_read(st->spi, chan->address);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
*val = scale_uv / 1000;
*val2 = (scale_uv % 1000) * 1000;
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int ad5504_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad5504_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;
return ad5504_spi_write(st->spi, chan->address, val);
default:
ret = -EINVAL;
}
return -EINVAL;
}
static const char * const ad5504_powerdown_modes[] = {
"20kohm_to_gnd",
"three_state",
};
static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ad5504_state *st = iio_priv(indio_dev);
return st->pwr_down_mode;
}
static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int mode)
{
struct ad5504_state *st = iio_priv(indio_dev);
st->pwr_down_mode = mode;
return 0;
}
static const struct iio_enum ad5504_powerdown_mode_enum = {
.items = ad5504_powerdown_modes,
.num_items = ARRAY_SIZE(ad5504_powerdown_modes),
.get = ad5504_get_powerdown_mode,
.set = ad5504_set_powerdown_mode,
};
static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
struct ad5504_state *st = iio_priv(indio_dev);
return sprintf(buf, "%d\n",
!(st->pwr_down_mask & (1 << chan->channel)));
}
static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
size_t len)
{
bool pwr_down;
int ret;
struct ad5504_state *st = iio_priv(indio_dev);
ret = strtobool(buf, &pwr_down);
if (ret)
return ret;
if (pwr_down)
st->pwr_down_mask |= (1 << chan->channel);
else
st->pwr_down_mask &= ~(1 << chan->channel);
ret = ad5504_spi_write(st->spi, AD5504_ADDR_CTRL,
AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
AD5504_DAC_PWR(st->pwr_down_mask));
/* writes to the CTRL register must be followed by a NOOP */
ad5504_spi_write(st->spi, AD5504_ADDR_NOOP, 0);
return ret ? ret : len;
}
static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
static struct attribute *ad5504_ev_attributes[] = {
&iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
&iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
NULL,
};
static struct attribute_group ad5504_ev_attribute_group = {
.attrs = ad5504_ev_attributes,
.name = "events",
};
static irqreturn_t ad5504_event_handler(int irq, void *private)
{
iio_push_event(private,
IIO_UNMOD_EVENT_CODE(IIO_TEMP,
0,
IIO_EV_TYPE_THRESH,
IIO_EV_DIR_RISING),
iio_get_time_ns());
return IRQ_HANDLED;
}
static const struct iio_info ad5504_info = {
.write_raw = ad5504_write_raw,
.read_raw = ad5504_read_raw,
.event_attrs = &ad5504_ev_attribute_group,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
{
.name = "powerdown",
.read = ad5504_read_dac_powerdown,
.write = ad5504_write_dac_powerdown,
},
IIO_ENUM("powerdown_mode", true, &ad5504_powerdown_mode_enum),
IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
{ },
};
#define AD5504_CHANNEL(_chan) { \
.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 = AD5504_ADDR_DAC(_chan), \
.scan_type = IIO_ST('u', 12, 16, 0), \
.ext_info = ad5504_ext_info, \
}
static const struct iio_chan_spec ad5504_channels[] = {
AD5504_CHANNEL(0),
AD5504_CHANNEL(1),
AD5504_CHANNEL(2),
AD5504_CHANNEL(3),
};
static int ad5504_probe(struct spi_device *spi)
{
struct ad5504_platform_data *pdata = spi->dev.platform_data;
struct iio_dev *indio_dev;
struct ad5504_state *st;
struct regulator *reg;
int ret, voltage_uv = 0;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
reg = devm_regulator_get(&spi->dev, "vcc");
if (!IS_ERR(reg)) {
ret = regulator_enable(reg);
if (ret)
return ret;
ret = regulator_get_voltage(reg);
if (ret < 0)
goto error_disable_reg;
voltage_uv = ret;
}
spi_set_drvdata(spi, indio_dev);
st = iio_priv(indio_dev);
if (voltage_uv)
st->vref_mv = voltage_uv / 1000;
else if (pdata)
st->vref_mv = pdata->vref_mv;
else
dev_warn(&spi->dev, "reference voltage unspecified\n");
st->reg = reg;
st->spi = spi;
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(st->spi)->name;
indio_dev->info = &ad5504_info;
if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
indio_dev->num_channels = 1;
else
indio_dev->num_channels = 4;
indio_dev->channels = ad5504_channels;
indio_dev->modes = INDIO_DIRECT_MODE;
if (spi->irq) {
ret = devm_request_threaded_irq(&spi->dev, spi->irq,
NULL,
&ad5504_event_handler,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
spi_get_device_id(st->spi)->name,
indio_dev);
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(reg))
regulator_disable(reg);
return ret;
}
static int ad5504_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad5504_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 ad5504_id[] = {
{"ad5504", ID_AD5504},
{"ad5501", ID_AD5501},
{}
};
MODULE_DEVICE_TABLE(spi, ad5504_id);
static struct spi_driver ad5504_driver = {
.driver = {
.name = "ad5504",
.owner = THIS_MODULE,
},
.probe = ad5504_probe,
.remove = ad5504_remove,
.id_table = ad5504_id,
};
module_spi_driver(ad5504_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
MODULE_LICENSE("GPL v2");