- 根目录:
- drivers
- iio
- dac
- ad5449.c
/*
* AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog
* Converter driver.
*
* Copyright 2012 Analog Devices Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*
* 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/regulator/consumer.h>
#include <asm/unaligned.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/platform_data/ad5449.h>
#define AD5449_MAX_CHANNELS 2
#define AD5449_MAX_VREFS 2
#define AD5449_CMD_NOOP 0x0
#define AD5449_CMD_LOAD_AND_UPDATE(x) (0x1 + (x) * 3)
#define AD5449_CMD_READ(x) (0x2 + (x) * 3)
#define AD5449_CMD_LOAD(x) (0x3 + (x) * 3)
#define AD5449_CMD_CTRL 13
#define AD5449_CTRL_SDO_OFFSET 10
#define AD5449_CTRL_DAISY_CHAIN BIT(9)
#define AD5449_CTRL_HCLR_TO_MIDSCALE BIT(8)
#define AD5449_CTRL_SAMPLE_RISING BIT(7)
/**
* struct ad5449_chip_info - chip specific information
* @channels: Channel specification
* @num_channels: Number of channels
* @has_ctrl: Chip has a control register
*/
struct ad5449_chip_info {
const struct iio_chan_spec *channels;
unsigned int num_channels;
bool has_ctrl;
};
/**
* struct ad5449 - driver instance specific data
* @spi: the SPI device for this driver instance
* @chip_info: chip model specific constants, available modes etc
* @vref_reg: vref supply regulators
* @has_sdo: whether the SDO line is connected
* @dac_cache: Cache for the DAC values
* @data: spi transfer buffers
*/
struct ad5449 {
struct spi_device *spi;
const struct ad5449_chip_info *chip_info;
struct regulator_bulk_data vref_reg[AD5449_MAX_VREFS];
bool has_sdo;
uint16_t dac_cache[AD5449_MAX_CHANNELS];
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
__be16 data[2] ____cacheline_aligned;
};
enum ad5449_type {
ID_AD5426,
ID_AD5429,
ID_AD5432,
ID_AD5439,
ID_AD5443,
ID_AD5449,
};
static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr,
unsigned int val)
{
struct ad5449 *st = iio_priv(indio_dev);
int ret;
mutex_lock(&indio_dev->mlock);
st->data[0] = cpu_to_be16((addr << 12) | val);
ret = spi_write(st->spi, st->data, 2);
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
unsigned int *val)
{
struct ad5449 *st = iio_priv(indio_dev);
int ret;
struct spi_transfer t[] = {
{
.tx_buf = &st->data[0],
.len = 2,
.cs_change = 1,
}, {
.tx_buf = &st->data[1],
.rx_buf = &st->data[1],
.len = 2,
},
};
mutex_lock(&indio_dev->mlock);
st->data[0] = cpu_to_be16(addr << 12);
st->data[1] = cpu_to_be16(AD5449_CMD_NOOP);
ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
if (ret < 0)
goto out_unlock;
*val = be16_to_cpu(st->data[1]);
out_unlock:
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5449_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2, long info)
{
struct ad5449 *st = iio_priv(indio_dev);
struct regulator_bulk_data *reg;
int scale_uv;
int ret;
switch (info) {
case IIO_CHAN_INFO_RAW:
if (st->has_sdo) {
ret = ad5449_read(indio_dev,
AD5449_CMD_READ(chan->address), val);
if (ret)
return ret;
*val &= 0xfff;
} else {
*val = st->dac_cache[chan->address];
}
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
reg = &st->vref_reg[chan->channel];
scale_uv = regulator_get_voltage(reg->consumer);
if (scale_uv < 0)
return scale_uv;
*val = scale_uv / 1000;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
break;
}
return -EINVAL;
}
static int ad5449_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long info)
{
struct ad5449 *st = iio_priv(indio_dev);
int ret;
switch (info) {
case IIO_CHAN_INFO_RAW:
if (val < 0 || val >= (1 << chan->scan_type.realbits))
return -EINVAL;
ret = ad5449_write(indio_dev,
AD5449_CMD_LOAD_AND_UPDATE(chan->address),
val << chan->scan_type.shift);
if (ret == 0)
st->dac_cache[chan->address] = val;
break;
default:
ret = -EINVAL;
}
return ret;
}
static const struct iio_info ad5449_info = {
.read_raw = ad5449_read_raw,
.write_raw = ad5449_write_raw,
.driver_module = THIS_MODULE,
};
#define AD5449_CHANNEL(chan, bits) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = (chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.address = (chan), \
.scan_type = { \
.sign = 'u', \
.realbits = (bits), \
.storagebits = 16, \
.shift = 12 - (bits), \
}, \
}
#define DECLARE_AD5449_CHANNELS(name, bits) \
const struct iio_chan_spec name[] = { \
AD5449_CHANNEL(0, bits), \
AD5449_CHANNEL(1, bits), \
}
static DECLARE_AD5449_CHANNELS(ad5429_channels, 8);
static DECLARE_AD5449_CHANNELS(ad5439_channels, 10);
static DECLARE_AD5449_CHANNELS(ad5449_channels, 12);
static const struct ad5449_chip_info ad5449_chip_info[] = {
[ID_AD5426] = {
.channels = ad5429_channels,
.num_channels = 1,
.has_ctrl = false,
},
[ID_AD5429] = {
.channels = ad5429_channels,
.num_channels = 2,
.has_ctrl = true,
},
[ID_AD5432] = {
.channels = ad5439_channels,
.num_channels = 1,
.has_ctrl = false,
},
[ID_AD5439] = {
.channels = ad5439_channels,
.num_channels = 2,
.has_ctrl = true,
},
[ID_AD5443] = {
.channels = ad5449_channels,
.num_channels = 1,
.has_ctrl = false,
},
[ID_AD5449] = {
.channels = ad5449_channels,
.num_channels = 2,
.has_ctrl = true,
},
};
static const char *ad5449_vref_name(struct ad5449 *st, int n)
{
if (st->chip_info->num_channels == 1)
return "VREF";
if (n == 0)
return "VREFA";
else
return "VREFB";
}
static int ad5449_spi_probe(struct spi_device *spi)
{
struct ad5449_platform_data *pdata = spi->dev.platform_data;
const struct spi_device_id *id = spi_get_device_id(spi);
struct iio_dev *indio_dev;
struct ad5449 *st;
unsigned int i;
int ret;
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->chip_info = &ad5449_chip_info[id->driver_data];
st->spi = spi;
for (i = 0; i < st->chip_info->num_channels; ++i)
st->vref_reg[i].supply = ad5449_vref_name(st, i);
ret = devm_regulator_bulk_get(&spi->dev, st->chip_info->num_channels,
st->vref_reg);
if (ret)
return ret;
ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg);
if (ret)
return ret;
indio_dev->dev.parent = &spi->dev;
indio_dev->name = id->name;
indio_dev->info = &ad5449_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
if (st->chip_info->has_ctrl) {
unsigned int ctrl = 0x00;
if (pdata) {
if (pdata->hardware_clear_to_midscale)
ctrl |= AD5449_CTRL_HCLR_TO_MIDSCALE;
ctrl |= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET;
st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED;
} else {
st->has_sdo = true;
}
ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl);
}
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg;
return 0;
error_disable_reg:
regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
return ret;
}
static int ad5449_spi_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad5449 *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
return 0;
}
static const struct spi_device_id ad5449_spi_ids[] = {
{ "ad5415", ID_AD5449 },
{ "ad5426", ID_AD5426 },
{ "ad5429", ID_AD5429 },
{ "ad5432", ID_AD5432 },
{ "ad5439", ID_AD5439 },
{ "ad5443", ID_AD5443 },
{ "ad5449", ID_AD5449 },
{}
};
MODULE_DEVICE_TABLE(spi, ad5449_spi_ids);
static struct spi_driver ad5449_spi_driver = {
.driver = {
.name = "ad5449",
.owner = THIS_MODULE,
},
.probe = ad5449_spi_probe,
.remove = ad5449_spi_remove,
.id_table = ad5449_spi_ids,
};
module_spi_driver(ad5449_spi_driver);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs");
MODULE_LICENSE("GPL v2");