377 строки
8.6 KiB
C
377 строки
8.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* AD7170/AD7171 and AD7780/AD7781 SPI ADC driver
|
|
*
|
|
* Copyright 2011 Analog Devices Inc.
|
|
* Copyright 2019 Renato Lui Geh
|
|
*/
|
|
|
|
#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)
|
|
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,
|
|
};
|
|
|
|
#define AD7780_CHANNEL(bits, wordsize) \
|
|
AD_SD_CHANNEL(1, 0, 0, bits, 32, (wordsize) - (bits))
|
|
#define AD7170_CHANNEL(bits, wordsize) \
|
|
AD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, (wordsize) - (bits))
|
|
|
|
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 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];
|
|
|
|
spi_set_drvdata(spi, indio_dev);
|
|
|
|
indio_dev->dev.parent = &spi->dev;
|
|
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)
|
|
goto error_cleanup_buffer_and_trigger;
|
|
|
|
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 = ad_sd_setup_buffer_and_trigger(indio_dev);
|
|
if (ret)
|
|
goto error_disable_reg;
|
|
|
|
ret = iio_device_register(indio_dev);
|
|
if (ret)
|
|
goto error_cleanup_buffer_and_trigger;
|
|
|
|
return 0;
|
|
|
|
error_cleanup_buffer_and_trigger:
|
|
ad_sd_cleanup_buffer_and_trigger(indio_dev);
|
|
error_disable_reg:
|
|
regulator_disable(st->reg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ad7780_remove(struct spi_device *spi)
|
|
{
|
|
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
|
struct ad7780_state *st = iio_priv(indio_dev);
|
|
|
|
iio_device_unregister(indio_dev);
|
|
ad_sd_cleanup_buffer_and_trigger(indio_dev);
|
|
|
|
regulator_disable(st->reg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
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,
|
|
.remove = ad7780_remove,
|
|
.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");
|