#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/bits.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/adc/ad_sigma_delta.h>
#define AD7780_RDY BIT(7)
#define AD7780_FILTER BIT(6)
#define AD7780_ERR BIT(5)
#define AD7780_ID1 BIT(4)
#define AD7780_ID0 BIT(3)
#define AD7780_GAIN BIT(2)
#define AD7170_ID 0
#define AD7171_ID 1
#define AD7780_ID 1
#define AD7781_ID 0
#define AD7780_ID_MASK (AD7780_ID0 | AD7780_ID1)
#define AD7780_PATTERN_GOOD 1
#define AD7780_PATTERN_MASK GENMASK(1, 0)
#define AD7170_PATTERN_GOOD 5
#define AD7170_PATTERN_MASK GENMASK(2, 0)
#define AD7780_GAIN_MIDPOINT 64
#define AD7780_FILTER_MIDPOINT 13350
static const unsigned int ad778x_gain[2] = { 1, 128 };
static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
struct ad7780_chip_info {
struct iio_chan_spec channel;
unsigned int pattern_mask;
unsigned int pattern;
bool is_ad778x;
};
struct ad7780_state {
const struct ad7780_chip_info *chip_info;
struct regulator *reg;
struct gpio_desc *powerdown_gpio;
struct gpio_desc *gain_gpio;
struct gpio_desc *filter_gpio;
unsigned int gain;
unsigned int odr;
unsigned int int_vref_mv;
struct ad_sigma_delta sd;
};
enum ad7780_supported_device_ids {
ID_AD7170,
ID_AD7171,
ID_AD7780,
ID_AD7781,
};
static struct ad7780_state *ad_sigma_delta_to_ad7780(struct ad_sigma_delta *sd)
{
return container_of(sd, struct ad7780_state, sd);
}
static int ad7780_set_mode(struct ad_sigma_delta *sigma_delta,
enum ad_sigma_delta_mode mode)
{
struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
unsigned int val;
switch (mode) {
case AD_SD_MODE_SINGLE:
case AD_SD_MODE_CONTINUOUS:
val = 1;
break;
default:
val = 0;
break;
}
gpiod_set_value(st->powerdown_gpio, val);
return 0;
}
static int ad7780_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad7780_state *st = iio_priv(indio_dev);
int voltage_uv;
switch (m) {
case IIO_CHAN_INFO_RAW:
return ad_sigma_delta_single_conversion(indio_dev, chan, val);
case IIO_CHAN_INFO_SCALE:
voltage_uv = regulator_get_voltage(st->reg);
if (voltage_uv < 0)
return voltage_uv;
voltage_uv /= 1000;
*val = voltage_uv * st->gain;
*val2 = chan->scan_type.realbits - 1;
st->int_vref_mv = voltage_uv;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
*val = -(1 << (chan->scan_type.realbits - 1));
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = st->odr;
return IIO_VAL_INT;
default:
break;
}
return -EINVAL;
}
static int ad7780_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long m)
{
struct ad7780_state *st = iio_priv(indio_dev);
const struct ad7780_chip_info *chip_info = st->chip_info;
unsigned long long vref;
unsigned int full_scale, gain;
if (!chip_info->is_ad778x)
return -EINVAL;
switch (m) {
case IIO_CHAN_INFO_SCALE:
if (val != 0 || val2 == 0)
return -EINVAL;
vref = st->int_vref_mv * 1000000LL;
full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
gain = DIV_ROUND_CLOSEST_ULL(vref, full_scale);
gain = DIV_ROUND_CLOSEST(gain, val2);
st->gain = gain;
if (gain < AD7780_GAIN_MIDPOINT)
gain = 0;
else
gain = 1;
gpiod_set_value(st->gain_gpio, gain);
break;
case IIO_CHAN_INFO_SAMP_FREQ:
if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
val = 0;
else
val = 1;
st->odr = ad778x_odr_avail[val];
gpiod_set_value(st->filter_gpio, val);
break;
default:
break;
}
return 0;
}
static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
unsigned int raw_sample)
{
struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
const struct ad7780_chip_info *chip_info = st->chip_info;
if ((raw_sample & AD7780_ERR) ||
((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
return -EIO;
if (chip_info->is_ad778x) {
st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
}
return 0;
}
static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
.set_mode = ad7780_set_mode,
.postprocess_sample = ad7780_postprocess_sample,
.has_registers = false,
.irq_flags = IRQF_TRIGGER_FALLING,
};
#define _AD7780_CHANNEL(_bits, _wordsize, _mask_all) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = 0, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.info_mask_shared_by_all = _mask_all, \
.scan_index = 1, \
.scan_type = { \
.sign = 'u', \
.realbits = (_bits), \
.storagebits = 32, \
.shift = (_wordsize) - (_bits), \
.endianness = IIO_BE, \
}, \
}
#define AD7780_CHANNEL(_bits, _wordsize) \
_AD7780_CHANNEL(_bits, _wordsize, BIT(IIO_CHAN_INFO_SAMP_FREQ))
#define AD7170_CHANNEL(_bits, _wordsize) \
_AD7780_CHANNEL(_bits, _wordsize, 0)
static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
[ID_AD7170] = {
.channel = AD7170_CHANNEL(12, 24),
.pattern = AD7170_PATTERN_GOOD,
.pattern_mask = AD7170_PATTERN_MASK,
.is_ad778x = false,
},
[ID_AD7171] = {
.channel = AD7170_CHANNEL(16, 24),
.pattern = AD7170_PATTERN_GOOD,
.pattern_mask = AD7170_PATTERN_MASK,
.is_ad778x = false,
},
[ID_AD7780] = {
.channel = AD7780_CHANNEL(24, 32),
.pattern = AD7780_PATTERN_GOOD,
.pattern_mask = AD7780_PATTERN_MASK,
.is_ad778x = true,
},
[ID_AD7781] = {
.channel = AD7780_CHANNEL(20, 32),
.pattern = AD7780_PATTERN_GOOD,
.pattern_mask = AD7780_PATTERN_MASK,
.is_ad778x = true,
},
};
static const struct iio_info ad7780_info = {
.read_raw = ad7780_read_raw,
.write_raw = ad7780_write_raw,
};
static int ad7780_init_gpios(struct device *dev, struct ad7780_state *st)
{
int ret;
st->powerdown_gpio = devm_gpiod_get_optional(dev,
"powerdown",
GPIOD_OUT_LOW);
if (IS_ERR(st->powerdown_gpio)) {
ret = PTR_ERR(st->powerdown_gpio);
dev_err(dev, "Failed to request powerdown GPIO: %d\n", ret);
return ret;
}
if (!st->chip_info->is_ad778x)
return 0;
st->gain_gpio = devm_gpiod_get_optional(dev,
"adi,gain",
GPIOD_OUT_HIGH);
if (IS_ERR(st->gain_gpio)) {
ret = PTR_ERR(st->gain_gpio);
dev_err(dev, "Failed to request gain GPIO: %d\n", ret);
return ret;
}
st->filter_gpio = devm_gpiod_get_optional(dev,
"adi,filter",
GPIOD_OUT_HIGH);
if (IS_ERR(st->filter_gpio)) {
ret = PTR_ERR(st->filter_gpio);
dev_err(dev, "Failed to request filter GPIO: %d\n", ret);
return ret;
}
return 0;
}
static void ad7780_reg_disable(void *reg)
{
regulator_disable(reg);
}
static int ad7780_probe(struct spi_device *spi)
{
struct ad7780_state *st;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->gain = 1;
ad_sd_init(&st->sd, indio_dev, spi, &ad7780_sigma_delta_info);
st->chip_info =
&ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data];
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = &st->chip_info->channel;
indio_dev->num_channels = 1;
indio_dev->info = &ad7780_info;
ret = ad7780_init_gpios(&spi->dev, st);
if (ret)
return ret;
st->reg = devm_regulator_get(&spi->dev, "avdd");
if (IS_ERR(st->reg))
return PTR_ERR(st->reg);
ret = regulator_enable(st->reg);
if (ret) {
dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
return ret;
}
ret = devm_add_action_or_reset(&spi->dev, ad7780_reg_disable, st->reg);
if (ret)
return ret;
ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
if (ret)
return ret;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct spi_device_id ad7780_id[] = {
{ "ad7170", ID_AD7170 },
{ "ad7171", ID_AD7171 },
{ "ad7780", ID_AD7780 },
{ "ad7781", ID_AD7781 },
{ }
};
MODULE_DEVICE_TABLE(spi, ad7780_id);
static struct spi_driver ad7780_driver = {
.driver = {
.name = "ad7780",
},
.probe = ad7780_probe,
.id_table = ad7780_id,
};
module_spi_driver(ad7780_driver);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7780 and similar ADCs");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("IIO_AD_SIGMA_DELTA");
