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// SPDX-License-Identifier: GPL-2.0-only
/*
* Maxim MAX5522
* Dual, Ultra-Low-Power 10-Bit, Voltage-Output DACs
*
* Copyright 2022 Timesys Corp.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#define MAX5522_MAX_ADDR 15
#define MAX5522_CTRL_NONE 0
#define MAX5522_CTRL_LOAD_IN_A 9
#define MAX5522_CTRL_LOAD_IN_B 10
#define MAX5522_REG_DATA(x) ((x) + MAX5522_CTRL_LOAD_IN_A)
struct max5522_chip_info {
const char *name;
const struct iio_chan_spec *channels;
unsigned int num_channels;
};
struct max5522_state {
struct regmap *regmap;
const struct max5522_chip_info *chip_info;
unsigned short dac_cache[2];
struct regulator *vrefin_reg;
};
#define MAX5522_CHANNEL(chan) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = chan, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.scan_type = { \
.sign = 'u', \
.realbits = 10, \
.storagebits = 16, \
.shift = 2, \
} \
}
static const struct iio_chan_spec max5522_channels[] = {
MAX5522_CHANNEL(0),
MAX5522_CHANNEL(1),
};
enum max5522_type {
ID_MAX5522,
};
static const struct max5522_chip_info max5522_chip_info_tbl[] = {
[ID_MAX5522] = {
.name = "max5522",
.channels = max5522_channels,
.num_channels = 2,
},
};
static inline int max5522_info_to_reg(struct iio_chan_spec const *chan)
{
return MAX5522_REG_DATA(chan->channel);
}
static int max5522_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long info)
{
struct max5522_state *state = iio_priv(indio_dev);
int ret;
switch (info) {
case IIO_CHAN_INFO_RAW:
*val = state->dac_cache[chan->channel];
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(state->vrefin_reg);
if (ret < 0)
return -EINVAL;
*val = ret / 1000;
*val2 = 10;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
return -EINVAL;
}
static int max5522_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long info)
{
struct max5522_state *state = iio_priv(indio_dev);
int rval;
if (val > 1023 || val < 0)
return -EINVAL;
rval = regmap_write(state->regmap, max5522_info_to_reg(chan),
val << chan->scan_type.shift);
if (rval < 0)
return rval;
state->dac_cache[chan->channel] = val;
return 0;
}
static const struct iio_info max5522_info = {
.read_raw = max5522_read_raw,
.write_raw = max5522_write_raw,
};
static const struct regmap_config max5522_regmap_config = {
.reg_bits = 4,
.val_bits = 12,
.max_register = MAX5522_MAX_ADDR,
};
static int max5522_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
struct iio_dev *indio_dev;
struct max5522_state *state;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
if (indio_dev == NULL) {
dev_err(&spi->dev, "failed to allocate iio device\n");
return -ENOMEM;
}
state = iio_priv(indio_dev);
state->chip_info = device_get_match_data(&spi->dev);
if (!state->chip_info) {
state->chip_info =
(struct max5522_chip_info *)(id->driver_data);
if (!state->chip_info)
return -EINVAL;
}
state->vrefin_reg = devm_regulator_get(&spi->dev, "vrefin");
if (IS_ERR(state->vrefin_reg))
return dev_err_probe(&spi->dev, PTR_ERR(state->vrefin_reg),
"Vrefin regulator not specified\n");
ret = regulator_enable(state->vrefin_reg);
if (ret) {
return dev_err_probe(&spi->dev, ret,
"Failed to enable vref regulators\n");
}
state->regmap = devm_regmap_init_spi(spi, &max5522_regmap_config);
if (IS_ERR(state->regmap))
return PTR_ERR(state->regmap);
indio_dev->info = &max5522_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = max5522_channels;
indio_dev->num_channels = ARRAY_SIZE(max5522_channels);
indio_dev->name = max5522_chip_info_tbl[ID_MAX5522].name;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct spi_device_id max5522_ids[] = {
{ "max5522", (kernel_ulong_t)&max5522_chip_info_tbl[ID_MAX5522] },
{}
};
MODULE_DEVICE_TABLE(spi, max5522_ids);
static const struct of_device_id max5522_of_match[] = {
{
.compatible = "maxim,max5522",
.data = &max5522_chip_info_tbl[ID_MAX5522],
},
{}
};
MODULE_DEVICE_TABLE(of, max5522_of_match);
static struct spi_driver max5522_spi_driver = {
.driver = {
.name = "max5522",
.of_match_table = max5522_of_match,
},
.probe = max5522_spi_probe,
.id_table = max5522_ids,
};
module_spi_driver(max5522_spi_driver);
MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@timesys.com");
MODULE_DESCRIPTION("MAX5522 DAC driver");
MODULE_LICENSE("GPL");
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