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// SPDX-License-Identifier: GPL-2.0-only
/*
* AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter
*
* Copyright 2016 Qtechnology A/S
* 2016 Ricardo Ribalda <ricardo.ribalda@gmail.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/bitops.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/platform_data/ad5761.h>
#define AD5761_ADDR(addr) ((addr & 0xf) << 16)
#define AD5761_ADDR_NOOP 0x0
#define AD5761_ADDR_DAC_WRITE 0x3
#define AD5761_ADDR_CTRL_WRITE_REG 0x4
#define AD5761_ADDR_SW_DATA_RESET 0x7
#define AD5761_ADDR_DAC_READ 0xb
#define AD5761_ADDR_CTRL_READ_REG 0xc
#define AD5761_ADDR_SW_FULL_RESET 0xf
#define AD5761_CTRL_USE_INTVREF BIT(5)
#define AD5761_CTRL_ETS BIT(6)
/**
* struct ad5761_chip_info - chip specific information
* @int_vref: Value of the internal reference voltage in mV - 0 if external
* reference voltage is used
* @channel: channel specification
*/
struct ad5761_chip_info {
unsigned long int_vref;
const struct iio_chan_spec channel;
};
struct ad5761_range_params {
int m;
int c;
};
enum ad5761_supported_device_ids {
ID_AD5721,
ID_AD5721R,
ID_AD5761,
ID_AD5761R,
};
/**
* struct ad5761_state - driver instance specific data
* @spi: spi_device
* @vref_reg: reference voltage regulator
* @use_intref: true when the internal voltage reference is used
* @vref: actual voltage reference in mVolts
* @range: output range mode used
* @data: cache aligned spi buffer
*/
struct ad5761_state {
struct spi_device *spi;
struct regulator *vref_reg;
bool use_intref;
int vref;
enum ad5761_voltage_range range;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
union {
__be32 d32;
u8 d8[4];
} data[3] ____cacheline_aligned;
};
static const struct ad5761_range_params ad5761_range_params[] = {
[AD5761_VOLTAGE_RANGE_M10V_10V] = {
.m = 80,
.c = 40,
},
[AD5761_VOLTAGE_RANGE_0V_10V] = {
.m = 40,
.c = 0,
},
[AD5761_VOLTAGE_RANGE_M5V_5V] = {
.m = 40,
.c = 20,
},
[AD5761_VOLTAGE_RANGE_0V_5V] = {
.m = 20,
.c = 0,
},
[AD5761_VOLTAGE_RANGE_M2V5_7V5] = {
.m = 40,
.c = 10,
},
[AD5761_VOLTAGE_RANGE_M3V_3V] = {
.m = 24,
.c = 12,
},
[AD5761_VOLTAGE_RANGE_0V_16V] = {
.m = 64,
.c = 0,
},
[AD5761_VOLTAGE_RANGE_0V_20V] = {
.m = 80,
.c = 0,
},
};
static int _ad5761_spi_write(struct ad5761_state *st, u8 addr, u16 val)
{
st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr) | val);
return spi_write(st->spi, &st->data[0].d8[1], 3);
}
static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val)
{
struct ad5761_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&indio_dev->mlock);
ret = _ad5761_spi_write(st, addr, val);
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int _ad5761_spi_read(struct ad5761_state *st, u8 addr, u16 *val)
{
int ret;
struct spi_transfer xfers[] = {
{
.tx_buf = &st->data[0].d8[1],
.bits_per_word = 8,
.len = 3,
.cs_change = true,
}, {
.tx_buf = &st->data[1].d8[1],
.rx_buf = &st->data[2].d8[1],
.bits_per_word = 8,
.len = 3,
},
};
st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr));
st->data[1].d32 = cpu_to_be32(AD5761_ADDR(AD5761_ADDR_NOOP));
ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
*val = be32_to_cpu(st->data[2].d32);
return ret;
}
static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val)
{
struct ad5761_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&indio_dev->mlock);
ret = _ad5761_spi_read(st, addr, val);
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad5761_spi_set_range(struct ad5761_state *st,
enum ad5761_voltage_range range)
{
u16 aux;
int ret;
aux = (range & 0x7) | AD5761_CTRL_ETS;
if (st->use_intref)
aux |= AD5761_CTRL_USE_INTVREF;
ret = _ad5761_spi_write(st, AD5761_ADDR_SW_FULL_RESET, 0);
if (ret)
return ret;
ret = _ad5761_spi_write(st, AD5761_ADDR_CTRL_WRITE_REG, aux);
if (ret)
return ret;
st->range = range;
return 0;
}
static int ad5761_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
struct ad5761_state *st;
int ret;
u16 aux;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = ad5761_spi_read(indio_dev, AD5761_ADDR_DAC_READ, &aux);
if (ret)
return ret;
*val = aux >> chan->scan_type.shift;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
st = iio_priv(indio_dev);
*val = st->vref * ad5761_range_params[st->range].m;
*val /= 10;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
st = iio_priv(indio_dev);
*val = -(1 << chan->scan_type.realbits);
*val *= ad5761_range_params[st->range].c;
*val /= ad5761_range_params[st->range].m;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad5761_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
u16 aux;
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
if (val2 || (val << chan->scan_type.shift) > 0xffff || val < 0)
return -EINVAL;
aux = val << chan->scan_type.shift;
return ad5761_spi_write(indio_dev, AD5761_ADDR_DAC_WRITE, aux);
}
static const struct iio_info ad5761_info = {
.read_raw = &ad5761_read_raw,
.write_raw = &ad5761_write_raw,
};
#define AD5761_CHAN(_bits) { \
.type = IIO_VOLTAGE, \
.output = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.scan_type = { \
.sign = 'u', \
.realbits = (_bits), \
.storagebits = 16, \
.shift = 16 - (_bits), \
}, \
}
static const struct ad5761_chip_info ad5761_chip_infos[] = {
[ID_AD5721] = {
.int_vref = 0,
.channel = AD5761_CHAN(12),
},
[ID_AD5721R] = {
.int_vref = 2500,
.channel = AD5761_CHAN(12),
},
[ID_AD5761] = {
.int_vref = 0,
.channel = AD5761_CHAN(16),
},
[ID_AD5761R] = {
.int_vref = 2500,
.channel = AD5761_CHAN(16),
},
};
static int ad5761_get_vref(struct ad5761_state *st,
const struct ad5761_chip_info *chip_info)
{
int ret;
st->vref_reg = devm_regulator_get_optional(&st->spi->dev, "vref");
if (PTR_ERR(st->vref_reg) == -ENODEV) {
/* Use Internal regulator */
if (!chip_info->int_vref) {
dev_err(&st->spi->dev,
"Voltage reference not found\n");
return -EIO;
}
st->use_intref = true;
st->vref = chip_info->int_vref;
return 0;
}
if (IS_ERR(st->vref_reg)) {
dev_err(&st->spi->dev,
"Error getting voltage reference regulator\n");
return PTR_ERR(st->vref_reg);
}
ret = regulator_enable(st->vref_reg);
if (ret) {
dev_err(&st->spi->dev,
"Failed to enable voltage reference\n");
return ret;
}
ret = regulator_get_voltage(st->vref_reg);
if (ret < 0) {
dev_err(&st->spi->dev,
"Failed to get voltage reference value\n");
goto disable_regulator_vref;
}
if (ret < 2000000 || ret > 3000000) {
dev_warn(&st->spi->dev,
"Invalid external voltage ref. value %d uV\n", ret);
ret = -EIO;
goto disable_regulator_vref;
}
st->vref = ret / 1000;
st->use_intref = false;
return 0;
disable_regulator_vref:
regulator_disable(st->vref_reg);
st->vref_reg = NULL;
return ret;
}
static int ad5761_probe(struct spi_device *spi)
{
struct iio_dev *iio_dev;
struct ad5761_state *st;
int ret;
const struct ad5761_chip_info *chip_info =
&ad5761_chip_infos[spi_get_device_id(spi)->driver_data];
enum ad5761_voltage_range voltage_range = AD5761_VOLTAGE_RANGE_0V_5V;
struct ad5761_platform_data *pdata = dev_get_platdata(&spi->dev);
iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!iio_dev)
return -ENOMEM;
st = iio_priv(iio_dev);
st->spi = spi;
spi_set_drvdata(spi, iio_dev);
ret = ad5761_get_vref(st, chip_info);
if (ret)
return ret;
if (pdata)
voltage_range = pdata->voltage_range;
ret = ad5761_spi_set_range(st, voltage_range);
if (ret)
goto disable_regulator_err;
iio_dev->dev.parent = &spi->dev;
iio_dev->info = &ad5761_info;
iio_dev->modes = INDIO_DIRECT_MODE;
iio_dev->channels = &chip_info->channel;
iio_dev->num_channels = 1;
iio_dev->name = spi_get_device_id(st->spi)->name;
ret = iio_device_register(iio_dev);
if (ret)
goto disable_regulator_err;
return 0;
disable_regulator_err:
if (!IS_ERR_OR_NULL(st->vref_reg))
regulator_disable(st->vref_reg);
return ret;
}
static int ad5761_remove(struct spi_device *spi)
{
struct iio_dev *iio_dev = spi_get_drvdata(spi);
struct ad5761_state *st = iio_priv(iio_dev);
iio_device_unregister(iio_dev);
if (!IS_ERR_OR_NULL(st->vref_reg))
regulator_disable(st->vref_reg);
return 0;
}
static const struct spi_device_id ad5761_id[] = {
{"ad5721", ID_AD5721},
{"ad5721r", ID_AD5721R},
{"ad5761", ID_AD5761},
{"ad5761r", ID_AD5761R},
{}
};
MODULE_DEVICE_TABLE(spi, ad5761_id);
static struct spi_driver ad5761_driver = {
.driver = {
.name = "ad5761",
},
.probe = ad5761_probe,
.remove = ad5761_remove,
.id_table = ad5761_id,
};
module_spi_driver(ad5761_driver);
MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@gmail.com>");
MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver");
MODULE_LICENSE("GPL v2");
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