M7350/kernel/drivers/iio/dac/ad5764.c

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/*
* Analog devices AD5764, AD5764R, AD5744, AD5744R quad-channel
* Digital to Analog Converters driver
*
* Copyright 2011 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/regulator/consumer.h>
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#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
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#define AD5764_REG_SF_NOP 0x0
#define AD5764_REG_SF_CONFIG 0x1
#define AD5764_REG_SF_CLEAR 0x4
#define AD5764_REG_SF_LOAD 0x5
#define AD5764_REG_DATA(x) ((2 << 3) | (x))
#define AD5764_REG_COARSE_GAIN(x) ((3 << 3) | (x))
#define AD5764_REG_FINE_GAIN(x) ((4 << 3) | (x))
#define AD5764_REG_OFFSET(x) ((5 << 3) | (x))
#define AD5764_NUM_CHANNELS 4
/**
* struct ad5764_chip_info - chip specific information
* @int_vref: Value of the internal reference voltage in uV - 0 if external
* reference voltage is used
* @channel channel specification
*/
struct ad5764_chip_info {
unsigned long int_vref;
const struct iio_chan_spec *channels;
};
/**
* struct ad5764_state - driver instance specific data
* @spi: spi_device
* @chip_info: chip info
* @vref_reg: vref supply regulators
* @data: spi transfer buffers
*/
struct ad5764_state {
struct spi_device *spi;
const struct ad5764_chip_info *chip_info;
struct regulator_bulk_data vref_reg[2];
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
union {
__be32 d32;
u8 d8[4];
} data[2] ____cacheline_aligned;
};
enum ad5764_type {
ID_AD5744,
ID_AD5744R,
ID_AD5764,
ID_AD5764R,
};
#define AD5764_CHANNEL(_chan, _bits) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = (_chan), \
.address = (_chan), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_CALIBSCALE) | \
BIT(IIO_CHAN_INFO_CALIBBIAS), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \
.scan_type = { \
.sign = 'u', \
.realbits = (_bits), \
.storagebits = 16, \
.shift = 16 - (_bits), \
}, \
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}
#define DECLARE_AD5764_CHANNELS(_name, _bits) \
const struct iio_chan_spec _name##_channels[] = { \
AD5764_CHANNEL(0, (_bits)), \
AD5764_CHANNEL(1, (_bits)), \
AD5764_CHANNEL(2, (_bits)), \
AD5764_CHANNEL(3, (_bits)), \
};
static DECLARE_AD5764_CHANNELS(ad5764, 16);
static DECLARE_AD5764_CHANNELS(ad5744, 14);
static const struct ad5764_chip_info ad5764_chip_infos[] = {
[ID_AD5744] = {
.int_vref = 0,
.channels = ad5744_channels,
},
[ID_AD5744R] = {
.int_vref = 5000000,
.channels = ad5744_channels,
},
[ID_AD5764] = {
.int_vref = 0,
.channels = ad5764_channels,
},
[ID_AD5764R] = {
.int_vref = 5000000,
.channels = ad5764_channels,
},
};
static int ad5764_write(struct iio_dev *indio_dev, unsigned int reg,
unsigned int val)
{
struct ad5764_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&indio_dev->mlock);
st->data[0].d32 = cpu_to_be32((reg << 16) | val);
ret = spi_write(st->spi, &st->data[0].d8[1], 3);
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5764_read(struct iio_dev *indio_dev, unsigned int reg,
unsigned int *val)
{
struct ad5764_state *st = iio_priv(indio_dev);
int ret;
struct spi_transfer t[] = {
{
.tx_buf = &st->data[0].d8[1],
.len = 3,
.cs_change = 1,
}, {
.rx_buf = &st->data[1].d8[1],
.len = 3,
},
};
mutex_lock(&indio_dev->mlock);
st->data[0].d32 = cpu_to_be32((1 << 23) | (reg << 16));
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ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
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if (ret >= 0)
*val = be32_to_cpu(st->data[1].d32) & 0xffff;
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5764_chan_info_to_reg(struct iio_chan_spec const *chan, long info)
{
switch (info) {
case 0:
return AD5764_REG_DATA(chan->address);
case IIO_CHAN_INFO_CALIBBIAS:
return AD5764_REG_OFFSET(chan->address);
case IIO_CHAN_INFO_CALIBSCALE:
return AD5764_REG_FINE_GAIN(chan->address);
default:
break;
}
return 0;
}
static int ad5764_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long info)
{
const int max_val = (1 << chan->scan_type.realbits);
unsigned int reg;
switch (info) {
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case IIO_CHAN_INFO_RAW:
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if (val >= max_val || val < 0)
return -EINVAL;
val <<= chan->scan_type.shift;
break;
case IIO_CHAN_INFO_CALIBBIAS:
if (val >= 128 || val < -128)
return -EINVAL;
break;
case IIO_CHAN_INFO_CALIBSCALE:
if (val >= 32 || val < -32)
return -EINVAL;
break;
default:
return -EINVAL;
}
reg = ad5764_chan_info_to_reg(chan, info);
return ad5764_write(indio_dev, reg, (u16)val);
}
static int ad5764_get_channel_vref(struct ad5764_state *st,
unsigned int channel)
{
if (st->chip_info->int_vref)
return st->chip_info->int_vref;
else
return regulator_get_voltage(st->vref_reg[channel / 2].consumer);
}
static int ad5764_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2, long info)
{
struct ad5764_state *st = iio_priv(indio_dev);
unsigned int reg;
int vref;
int ret;
switch (info) {
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case IIO_CHAN_INFO_RAW:
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reg = AD5764_REG_DATA(chan->address);
ret = ad5764_read(indio_dev, reg, val);
if (ret < 0)
return ret;
*val >>= chan->scan_type.shift;
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBBIAS:
reg = AD5764_REG_OFFSET(chan->address);
ret = ad5764_read(indio_dev, reg, val);
if (ret < 0)
return ret;
*val = sign_extend32(*val, 7);
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBSCALE:
reg = AD5764_REG_FINE_GAIN(chan->address);
ret = ad5764_read(indio_dev, reg, val);
if (ret < 0)
return ret;
*val = sign_extend32(*val, 5);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
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/* vout = 4 * vref + ((dac_code / 65536) - 0.5) */
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vref = ad5764_get_channel_vref(st, chan->channel);
if (vref < 0)
return vref;
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*val = vref * 4 / 1000;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
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case IIO_CHAN_INFO_OFFSET:
*val = -(1 << chan->scan_type.realbits) / 2;
return IIO_VAL_INT;
}
return -EINVAL;
}
static const struct iio_info ad5764_info = {
.read_raw = ad5764_read_raw,
.write_raw = ad5764_write_raw,
.driver_module = THIS_MODULE,
};
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static int ad5764_probe(struct spi_device *spi)
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{
enum ad5764_type type = spi_get_device_id(spi)->driver_data;
struct iio_dev *indio_dev;
struct ad5764_state *st;
int ret;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
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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->spi = spi;
st->chip_info = &ad5764_chip_infos[type];
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad5764_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->num_channels = AD5764_NUM_CHANNELS;
indio_dev->channels = st->chip_info->channels;
if (st->chip_info->int_vref == 0) {
st->vref_reg[0].supply = "vrefAB";
st->vref_reg[1].supply = "vrefCD";
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ret = devm_regulator_bulk_get(&st->spi->dev,
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ARRAY_SIZE(st->vref_reg), st->vref_reg);
if (ret) {
dev_err(&spi->dev, "Failed to request vref regulators: %d\n",
ret);
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return ret;
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}
ret = regulator_bulk_enable(ARRAY_SIZE(st->vref_reg),
st->vref_reg);
if (ret) {
dev_err(&spi->dev, "Failed to enable vref regulators: %d\n",
ret);
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return ret;
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}
}
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&spi->dev, "Failed to register iio device: %d\n", ret);
goto error_disable_reg;
}
return 0;
error_disable_reg:
if (st->chip_info->int_vref == 0)
regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg);
return ret;
}
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static int ad5764_remove(struct spi_device *spi)
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{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad5764_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
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if (st->chip_info->int_vref == 0)
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regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg);
return 0;
}
static const struct spi_device_id ad5764_ids[] = {
{ "ad5744", ID_AD5744 },
{ "ad5744r", ID_AD5744R },
{ "ad5764", ID_AD5764 },
{ "ad5764r", ID_AD5764R },
{ }
};
MODULE_DEVICE_TABLE(spi, ad5764_ids);
static struct spi_driver ad5764_driver = {
.driver = {
.name = "ad5764",
.owner = THIS_MODULE,
},
.probe = ad5764_probe,
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.remove = ad5764_remove,
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.id_table = ad5764_ids,
};
module_spi_driver(ad5764_driver);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Analog Devices AD5744/AD5744R/AD5764/AD5764R DAC");
MODULE_LICENSE("GPL v2");