// SPDX-License-Identifier: GPL-2.0-only
/*
* Analog Devices AD5766, AD5767
* Digital to Analog Converters driver
* Copyright 2019-2020 Analog Devices Inc.
*/
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <asm/unaligned.h>
#define AD5766_UPPER_WORD_SPI_MASK GENMASK(31, 16)
#define AD5766_LOWER_WORD_SPI_MASK GENMASK(15, 0)
#define AD5766_DITHER_SOURCE_MASK(ch) GENMASK(((2 * ch) + 1), (2 * ch))
#define AD5766_DITHER_SOURCE(ch, source) BIT((ch * 2) + source)
#define AD5766_DITHER_SCALE_MASK(x) AD5766_DITHER_SOURCE_MASK(x)
#define AD5766_DITHER_SCALE(ch, scale) (scale << (ch * 2))
#define AD5766_DITHER_ENABLE_MASK(ch) BIT(ch)
#define AD5766_DITHER_ENABLE(ch, state) ((!state) << ch)
#define AD5766_DITHER_INVERT_MASK(ch) BIT(ch)
#define AD5766_DITHER_INVERT(ch, state) (state << ch)
#define AD5766_CMD_NOP_MUX_OUT 0x00
#define AD5766_CMD_SDO_CNTRL 0x01
#define AD5766_CMD_WR_IN_REG(x) (0x10 | ((x) & GENMASK(3, 0)))
#define AD5766_CMD_WR_DAC_REG(x) (0x20 | ((x) & GENMASK(3, 0)))
#define AD5766_CMD_SW_LDAC 0x30
#define AD5766_CMD_SPAN_REG 0x40
#define AD5766_CMD_WR_PWR_DITHER 0x51
#define AD5766_CMD_WR_DAC_REG_ALL 0x60
#define AD5766_CMD_SW_FULL_RESET 0x70
#define AD5766_CMD_READBACK_REG(x) (0x80 | ((x) & GENMASK(3, 0)))
#define AD5766_CMD_DITHER_SIG_1 0x90
#define AD5766_CMD_DITHER_SIG_2 0xA0
#define AD5766_CMD_INV_DITHER 0xB0
#define AD5766_CMD_DITHER_SCALE_1 0xC0
#define AD5766_CMD_DITHER_SCALE_2 0xD0
#define AD5766_FULL_RESET_CODE 0x1234
enum ad5766_type {
ID_AD5766,
ID_AD5767,
};
enum ad5766_voltage_range {
AD5766_VOLTAGE_RANGE_M20V_0V,
AD5766_VOLTAGE_RANGE_M16V_to_0V,
AD5766_VOLTAGE_RANGE_M10V_to_0V,
AD5766_VOLTAGE_RANGE_M12V_to_14V,
AD5766_VOLTAGE_RANGE_M16V_to_10V,
AD5766_VOLTAGE_RANGE_M10V_to_6V,
AD5766_VOLTAGE_RANGE_M5V_to_5V,
AD5766_VOLTAGE_RANGE_M10V_to_10V,
};
/**
* struct ad5766_chip_info - chip specific information
* @num_channels: number of channels
* @channels: channel specification
*/
struct ad5766_chip_info {
unsigned int num_channels;
const struct iio_chan_spec *channels;
};
enum {
AD5766_DITHER_ENABLE,
AD5766_DITHER_INVERT,
AD5766_DITHER_SOURCE,
};
/*
* Dither signal can also be scaled.
* Available dither scale strings corresponding to "dither_scale" field in
* "struct ad5766_state".
*/
static const char * const ad5766_dither_scales[] = {
"1",
"0.75",
"0.5",
"0.25",
};
/**
* struct ad5766_state - driver instance specific data
* @spi: SPI device
* @lock: Lock used to restrict concurrent access to SPI device
* @chip_info: Chip model specific constants
* @gpio_reset: Reset GPIO, used to reset the device
* @crt_range: Current selected output range
* @dither_enable: Power enable bit for each channel dither block (for
* example, D15 = DAC 15,D8 = DAC 8, and D0 = DAC 0)
* 0 - Normal operation, 1 - Power down
* @dither_invert: Inverts the dither signal applied to the selected DAC
* outputs
* @dither_source: Selects between 2 possible sources:
* 1: N0, 2: N1
* Two bits are used for each channel
* @dither_scale: Two bits are used for each of the 16 channels:
* 0: 1 SCALING, 1: 0.75 SCALING, 2: 0.5 SCALING,
* 3: 0.25 SCALING.
* @data: SPI transfer buffers
*/
struct ad5766_state {
struct spi_device *spi;
struct mutex lock;
const struct ad5766_chip_info *chip_info;
struct gpio_desc *gpio_reset;
enum ad5766_voltage_range crt_range;
u16 dither_enable;
u16 dither_invert;
u32 dither_source;
u32 dither_scale;
union {
u32 d32;
u16 w16[2];
u8 b8[4];
} data[3] ____cacheline_aligned;
};
struct ad5766_span_tbl {
int min;
int max;
};
static const struct ad5766_span_tbl ad5766_span_tbl[] = {
[AD5766_VOLTAGE_RANGE_M20V_0V] = {-20, 0},
[AD5766_VOLTAGE_RANGE_M16V_to_0V] = {-16, 0},
[AD5766_VOLTAGE_RANGE_M10V_to_0V] = {-10, 0},
[AD5766_VOLTAGE_RANGE_M12V_to_14V] = {-12, 14},
[AD5766_VOLTAGE_RANGE_M16V_to_10V] = {-16, 10},
[AD5766_VOLTAGE_RANGE_M10V_to_6V] = {-10, 6},
[AD5766_VOLTAGE_RANGE_M5V_to_5V] = {-5, 5},
[AD5766_VOLTAGE_RANGE_M10V_to_10V] = {-10, 10},
};
static int __ad5766_spi_read(struct ad5766_state *st, u8 dac, int *val)
{
int ret;
struct spi_transfer xfers[] = {
{
.tx_buf = &st->data[0].d32,
.bits_per_word = 8,
.len = 3,
.cs_change = 1,
}, {
.tx_buf = &st->data[1].d32,
.rx_buf = &st->data[2].d32,
.bits_per_word = 8,
.len = 3,
},
};
st->data[0].d32 = AD5766_CMD_READBACK_REG(dac);
st->data[1].d32 = AD5766_CMD_NOP_MUX_OUT;
ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
if (ret)
return ret;
*val = st->data[2].w16[1];
return ret;
}
static int __ad5766_spi_write(struct ad5766_state *st, u8 command, u16 data)
{
st->data[0].b8[0] = command;
put_unaligned_be16(data, &st->data[0].b8[1]);
return spi_write(st->spi, &st->data[0].b8[0], 3);
}
static int ad5766_read(struct iio_dev *indio_dev, u8 dac, int *val)
{
struct ad5766_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->lock);
ret = __ad5766_spi_read(st, dac, val);
mutex_unlock(&st->lock);
return ret;
}
static int ad5766_write(struct iio_dev *indio_dev, u8 dac, u16 data)
{
struct ad5766_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->lock);
ret = __ad5766_spi_write(st, AD5766_CMD_WR_DAC_REG(dac), data);
mutex_unlock(&st->lock);
return ret;
}
static int ad5766_reset(struct ad5766_state *st)
{
int ret;
if (st->gpio_reset) {
gpiod_set_value_cansleep(st->gpio_reset, 1);
ndelay(100); /* t_reset >= 100ns */
gpiod_set_value_cansleep(st->gpio_reset, 0);
} else {
ret = __ad5766_spi_write(st, AD5766_CMD_SW_FULL_RESET,
AD5766_FULL_RESET_CODE);
if (ret < 0)
return ret;
}
/*
* Minimum time between a reset and the subsequent successful write is
* typically 25 ns
*/
ndelay(25);
return 0;
}
static int ad5766_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad5766_state *st = iio_priv(indio_dev);
int ret;
switch (m) {
case IIO_CHAN_INFO_RAW:
ret = ad5766_read(indio_dev, chan->address, val);
if (ret)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OFFSET:
*val = ad5766_span_tbl[st->crt_range].min;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = ad5766_span_tbl[st->crt_range].max -
ad5766_span_tbl[st->crt_range].min;
*val2 = st->chip_info->channels[0].scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
static int ad5766_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long info)
{
switch (info) {
case IIO_CHAN_INFO_RAW:
{
const int max_val = GENMASK(chan->scan_type.realbits - 1, 0);
if (val > max_val || val < 0)
return -EINVAL;
val <<= chan->scan_type.shift;
return ad5766_write(indio_dev, chan->address, val);
}
default:
return -EINVAL;
}
}
static const struct iio_info ad5766_info = {
.read_raw = ad5766_read_raw,
.write_raw = ad5766_write_raw,
};
static int ad5766_get_dither_source(struct iio_dev *dev,
const struct iio_chan_spec *chan)
{
struct ad5766_state *st = iio_priv(dev);
u32 source;
source = st->dither_source & AD5766_DITHER_SOURCE_MASK(chan->channel);
source = source >> (chan->channel * 2);
source -= 1;
return source;
}
static int ad5766_set_dither_source(struct iio_dev *dev,
const struct iio_chan_spec *chan,
unsigned int source)
{
struct ad5766_state *st = iio_priv(dev);
uint16_t val;
int ret;
st->dither_source &= ~AD5766_DITHER_SOURCE_MASK(chan->channel);
st->dither_source |= AD5766_DITHER_SOURCE(chan->channel, source);
val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_source);
ret = ad5766_write(dev, AD5766_CMD_DITHER_SIG_1, val);
if (ret)
return ret;
val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_source);
return ad5766_write(dev, AD5766_CMD_DITHER_SIG_2, val);
}
static int ad5766_get_dither_scale(struct iio_dev *dev,
const struct iio_chan_spec *chan)
{
struct ad5766_state *st = iio_priv(dev);
u32 scale;
scale = st->dither_scale & AD5766_DITHER_SCALE_MASK(chan->channel);
return (scale >> (chan->channel * 2));
}
static int ad5766_set_dither_scale(struct iio_dev *dev,
const struct iio_chan_spec *chan,
unsigned int scale)
{
int ret;
struct ad5766_state *st = iio_priv(dev);
uint16_t val;
st->dither_scale &= ~AD5766_DITHER_SCALE_MASK(chan->channel);
st->dither_scale |= AD5766_DITHER_SCALE(chan->channel, scale);
val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_scale);
ret = ad5766_write(dev, AD5766_CMD_DITHER_SCALE_1, val);
if (ret)
return ret;
val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_scale);
return ad5766_write(dev, AD5766_CMD_DITHER_SCALE_2, val);
}
static const struct iio_enum ad5766_dither_scale_enum = {
.items = ad5766_dither_scales,
.num_items = ARRAY_SIZE(ad5766_dither_scales),
.set = ad5766_set_dither_scale,
.get = ad5766_get_dither_scale,
};
static ssize_t ad5766_read_ext(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
char *buf)
{
struct ad5766_state *st = iio_priv(indio_dev);
switch (private) {
case AD5766_DITHER_ENABLE:
return sprintf(buf, "%u\n",
!(st->dither_enable & BIT(chan->channel)));
break;
case AD5766_DITHER_INVERT:
return sprintf(buf, "%u\n",
!!(st->dither_invert & BIT(chan->channel)));
break;
case AD5766_DITHER_SOURCE:
return sprintf(buf, "%d\n",
ad5766_get_dither_source(indio_dev, chan));
default:
return -EINVAL;
}
}
static ssize_t ad5766_write_ext(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
const char *buf, size_t len)
{
struct ad5766_state *st = iio_priv(indio_dev);
bool readin;
int ret;
ret = kstrtobool(buf, &readin);
if (ret)
return ret;
switch (private) {
case AD5766_DITHER_ENABLE:
st->dither_enable &= ~AD5766_DITHER_ENABLE_MASK(chan->channel);
st->dither_enable |= AD5766_DITHER_ENABLE(chan->channel,
readin);
ret = ad5766_write(indio_dev, AD5766_CMD_WR_PWR_DITHER,
st->dither_enable);
break;
case AD5766_DITHER_INVERT:
st->dither_invert &= ~AD5766_DITHER_INVERT_MASK(chan->channel);
st->dither_invert |= AD5766_DITHER_INVERT(chan->channel,
readin);
ret = ad5766_write(indio_dev, AD5766_CMD_INV_DITHER,
st->dither_invert);
break;
case AD5766_DITHER_SOURCE:
ret = ad5766_set_dither_source(indio_dev, chan, readin);
break;
default:
return -EINVAL;
}
return ret ? ret : len;
}
#define _AD5766_CHAN_EXT_INFO(_name, _what, _shared) { \
.name = _name, \
.read = ad5766_read_ext, \
.write = ad5766_write_ext, \
.private = _what, \
.shared = _shared, \
}
#define IIO_ENUM_AVAILABLE_SHARED(_name, _shared, _e) \
{ \
.name = (_name "_available"), \
.shared = _shared, \
.read = iio_enum_available_read, \
.private = (uintptr_t)(_e), \
}
static const struct iio_chan_spec_ext_info ad5766_ext_info[] = {
_AD5766_CHAN_EXT_INFO("dither_enable", AD5766_DITHER_ENABLE,
IIO_SEPARATE),
_AD5766_CHAN_EXT_INFO("dither_invert", AD5766_DITHER_INVERT,
IIO_SEPARATE),
_AD5766_CHAN_EXT_INFO("dither_source", AD5766_DITHER_SOURCE,
IIO_SEPARATE),
IIO_ENUM("dither_scale", IIO_SEPARATE, &ad5766_dither_scale_enum),
IIO_ENUM_AVAILABLE_SHARED("dither_scale",
IIO_SEPARATE,
&ad5766_dither_scale_enum),
{}
};
#define AD576x_CHANNEL(_chan, _bits) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = (_chan), \
.address = (_chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_SCALE), \
.scan_type = { \
.sign = 'u', \
.realbits = (_bits), \
.storagebits = 16, \
.shift = 16 - (_bits), \
}, \
.ext_info = ad5766_ext_info, \
}
#define DECLARE_AD576x_CHANNELS(_name, _bits) \
const struct iio_chan_spec _name[] = { \
AD576x_CHANNEL(0, (_bits)), \
AD576x_CHANNEL(1, (_bits)), \
AD576x_CHANNEL(2, (_bits)), \
AD576x_CHANNEL(3, (_bits)), \
AD576x_CHANNEL(4, (_bits)), \
AD576x_CHANNEL(5, (_bits)), \
AD576x_CHANNEL(6, (_bits)), \
AD576x_CHANNEL(7, (_bits)), \
AD576x_CHANNEL(8, (_bits)), \
AD576x_CHANNEL(9, (_bits)), \
AD576x_CHANNEL(10, (_bits)), \
AD576x_CHANNEL(11, (_bits)), \
AD576x_CHANNEL(12, (_bits)), \
AD576x_CHANNEL(13, (_bits)), \
AD576x_CHANNEL(14, (_bits)), \
AD576x_CHANNEL(15, (_bits)), \
}
static DECLARE_AD576x_CHANNELS(ad5766_channels, 16);
static DECLARE_AD576x_CHANNELS(ad5767_channels, 12);
static const struct ad5766_chip_info ad5766_chip_infos[] = {
[ID_AD5766] = {
.num_channels = ARRAY_SIZE(ad5766_channels),
.channels = ad5766_channels,
},
[ID_AD5767] = {
.num_channels = ARRAY_SIZE(ad5767_channels),
.channels = ad5767_channels,
},
};
static int ad5766_get_output_range(struct ad5766_state *st)
{
int i, ret, min, max, tmp[2];
ret = device_property_read_u32_array(&st->spi->dev,
"output-range-microvolts",
tmp, 2);
if (ret)
return ret;
min = tmp[0] / 1000000;
max = tmp[1] / 1000000;
for (i = 0; i < ARRAY_SIZE(ad5766_span_tbl); i++) {
if (ad5766_span_tbl[i].min != min ||
ad5766_span_tbl[i].max != max)
continue;
st->crt_range = i;
return 0;
}
return -EINVAL;
}
static int ad5766_default_setup(struct ad5766_state *st)
{
uint16_t val;
int ret, i;
/* Always issue a reset before writing to the span register. */
ret = ad5766_reset(st);
if (ret)
return ret;
ret = ad5766_get_output_range(st);
if (ret)
return ret;
/* Dither power down */
st->dither_enable = GENMASK(15, 0);
ret = __ad5766_spi_write(st, AD5766_CMD_WR_PWR_DITHER,
st->dither_enable);
if (ret)
return ret;
st->dither_source = 0;
for (i = 0; i < ARRAY_SIZE(ad5766_channels); i++)
st->dither_source |= AD5766_DITHER_SOURCE(i, 0);
val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_source);
ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SIG_1, val);
if (ret)
return ret;
val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_source);
ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SIG_2, val);
if (ret)
return ret;
st->dither_scale = 0;
val = FIELD_GET(AD5766_LOWER_WORD_SPI_MASK, st->dither_scale);
ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SCALE_1, val);
if (ret)
return ret;
val = FIELD_GET(AD5766_UPPER_WORD_SPI_MASK, st->dither_scale);
ret = __ad5766_spi_write(st, AD5766_CMD_DITHER_SCALE_2, val);
if (ret)
return ret;
st->dither_invert = 0;
ret = __ad5766_spi_write(st, AD5766_CMD_INV_DITHER, st->dither_invert);
if (ret)
return ret;
return __ad5766_spi_write(st, AD5766_CMD_SPAN_REG, st->crt_range);
}
static int ad5766_probe(struct spi_device *spi)
{
enum ad5766_type type;
struct iio_dev *indio_dev;
struct ad5766_state *st;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
mutex_init(&st->lock);
st->spi = spi;
type = spi_get_device_id(spi)->driver_data;
st->chip_info = &ad5766_chip_infos[type];
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
indio_dev->info = &ad5766_info;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(st->gpio_reset))
return PTR_ERR(st->gpio_reset);
ret = ad5766_default_setup(st);
if (ret)
return ret;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct of_device_id ad5766_dt_match[] = {
{ .compatible = "adi,ad5766" },
{ .compatible = "adi,ad5767" },
{}
};
MODULE_DEVICE_TABLE(of, ad5766_dt_match);
static const struct spi_device_id ad5766_spi_ids[] = {
{ "ad5766", ID_AD5766 },
{ "ad5767", ID_AD5767 },
{}
};
MODULE_DEVICE_TABLE(spi, ad5766_spi_ids);
static struct spi_driver ad5766_driver = {
.driver = {
.name = "ad5766",
.of_match_table = ad5766_dt_match,
},
.probe = ad5766_probe,
.id_table = ad5766_spi_ids,
};
module_spi_driver(ad5766_driver);
MODULE_AUTHOR("Denis-Gabriel Gheorghescu <denis.gheorghescu@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD5766/AD5767 DACs");
MODULE_LICENSE("GPL v2");
