// SPDX-License-Identifier: GPL-2.0+
|
/*
|
* AD7816 digital temperature sensor driver supporting AD7816/7/8
|
*
|
* Copyright 2010 Analog Devices Inc.
|
*/
|
|
#include <linux/interrupt.h>
|
#include <linux/gpio/consumer.h>
|
#include <linux/device.h>
|
#include <linux/kernel.h>
|
#include <linux/slab.h>
|
#include <linux/sysfs.h>
|
#include <linux/list.h>
|
#include <linux/spi/spi.h>
|
#include <linux/module.h>
|
|
#include <linux/iio/iio.h>
|
#include <linux/iio/sysfs.h>
|
#include <linux/iio/events.h>
|
|
/*
|
* AD7816 config masks
|
*/
|
#define AD7816_FULL 0x1
|
#define AD7816_PD 0x2
|
#define AD7816_CS_MASK 0x7
|
#define AD7816_CS_MAX 0x4
|
|
/*
|
* AD7816 temperature masks
|
*/
|
#define AD7816_VALUE_OFFSET 6
|
#define AD7816_BOUND_VALUE_BASE 0x8
|
#define AD7816_BOUND_VALUE_MIN -95
|
#define AD7816_BOUND_VALUE_MAX 152
|
#define AD7816_TEMP_FLOAT_OFFSET 2
|
#define AD7816_TEMP_FLOAT_MASK 0x3
|
|
/*
|
* struct ad7816_chip_info - chip specific information
|
*/
|
|
struct ad7816_chip_info {
|
kernel_ulong_t id;
|
struct spi_device *spi_dev;
|
struct gpio_desc *rdwr_pin;
|
struct gpio_desc *convert_pin;
|
struct gpio_desc *busy_pin;
|
u8 oti_data[AD7816_CS_MAX + 1];
|
u8 channel_id; /* 0 always be temperature */
|
u8 mode;
|
};
|
|
enum ad7816_type {
|
ID_AD7816,
|
ID_AD7817,
|
ID_AD7818,
|
};
|
|
/*
|
* ad7816 data access by SPI
|
*/
|
static int ad7816_spi_read(struct ad7816_chip_info *chip, u16 *data)
|
{
|
struct spi_device *spi_dev = chip->spi_dev;
|
int ret;
|
__be16 buf;
|
|
gpiod_set_value(chip->rdwr_pin, 1);
|
gpiod_set_value(chip->rdwr_pin, 0);
|
ret = spi_write(spi_dev, &chip->channel_id, sizeof(chip->channel_id));
|
if (ret < 0) {
|
dev_err(&spi_dev->dev, "SPI channel setting error\n");
|
return ret;
|
}
|
gpiod_set_value(chip->rdwr_pin, 1);
|
|
if (chip->mode == AD7816_PD) { /* operating mode 2 */
|
gpiod_set_value(chip->convert_pin, 1);
|
gpiod_set_value(chip->convert_pin, 0);
|
} else { /* operating mode 1 */
|
gpiod_set_value(chip->convert_pin, 0);
|
gpiod_set_value(chip->convert_pin, 1);
|
}
|
|
if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
|
while (gpiod_get_value(chip->busy_pin))
|
cpu_relax();
|
}
|
|
gpiod_set_value(chip->rdwr_pin, 0);
|
gpiod_set_value(chip->rdwr_pin, 1);
|
ret = spi_read(spi_dev, &buf, sizeof(*data));
|
if (ret < 0) {
|
dev_err(&spi_dev->dev, "SPI data read error\n");
|
return ret;
|
}
|
|
*data = be16_to_cpu(buf);
|
|
return ret;
|
}
|
|
static int ad7816_spi_write(struct ad7816_chip_info *chip, u8 data)
|
{
|
struct spi_device *spi_dev = chip->spi_dev;
|
int ret;
|
|
gpiod_set_value(chip->rdwr_pin, 1);
|
gpiod_set_value(chip->rdwr_pin, 0);
|
ret = spi_write(spi_dev, &data, sizeof(data));
|
if (ret < 0)
|
dev_err(&spi_dev->dev, "SPI oti data write error\n");
|
|
return ret;
|
}
|
|
static ssize_t ad7816_show_mode(struct device *dev,
|
struct device_attribute *attr,
|
char *buf)
|
{
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
struct ad7816_chip_info *chip = iio_priv(indio_dev);
|
|
if (chip->mode)
|
return sprintf(buf, "power-save\n");
|
return sprintf(buf, "full\n");
|
}
|
|
static ssize_t ad7816_store_mode(struct device *dev,
|
struct device_attribute *attr,
|
const char *buf,
|
size_t len)
|
{
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
struct ad7816_chip_info *chip = iio_priv(indio_dev);
|
|
if (strcmp(buf, "full")) {
|
gpiod_set_value(chip->rdwr_pin, 1);
|
chip->mode = AD7816_FULL;
|
} else {
|
gpiod_set_value(chip->rdwr_pin, 0);
|
chip->mode = AD7816_PD;
|
}
|
|
return len;
|
}
|
|
static IIO_DEVICE_ATTR(mode, 0644,
|
ad7816_show_mode,
|
ad7816_store_mode,
|
0);
|
|
static ssize_t ad7816_show_available_modes(struct device *dev,
|
struct device_attribute *attr,
|
char *buf)
|
{
|
return sprintf(buf, "full\npower-save\n");
|
}
|
|
static IIO_DEVICE_ATTR(available_modes, 0444, ad7816_show_available_modes,
|
NULL, 0);
|
|
static ssize_t ad7816_show_channel(struct device *dev,
|
struct device_attribute *attr,
|
char *buf)
|
{
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
struct ad7816_chip_info *chip = iio_priv(indio_dev);
|
|
return sprintf(buf, "%d\n", chip->channel_id);
|
}
|
|
static ssize_t ad7816_store_channel(struct device *dev,
|
struct device_attribute *attr,
|
const char *buf,
|
size_t len)
|
{
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
struct ad7816_chip_info *chip = iio_priv(indio_dev);
|
unsigned long data;
|
int ret;
|
|
ret = kstrtoul(buf, 10, &data);
|
if (ret)
|
return ret;
|
|
if (data > AD7816_CS_MAX && data != AD7816_CS_MASK) {
|
dev_err(&chip->spi_dev->dev, "Invalid channel id %lu for %s.\n",
|
data, indio_dev->name);
|
return -EINVAL;
|
} else if (strcmp(indio_dev->name, "ad7818") == 0 && data > 1) {
|
dev_err(&chip->spi_dev->dev,
|
"Invalid channel id %lu for ad7818.\n", data);
|
return -EINVAL;
|
} else if (strcmp(indio_dev->name, "ad7816") == 0 && data > 0) {
|
dev_err(&chip->spi_dev->dev,
|
"Invalid channel id %lu for ad7816.\n", data);
|
return -EINVAL;
|
}
|
|
chip->channel_id = data;
|
|
return len;
|
}
|
|
static IIO_DEVICE_ATTR(channel, 0644,
|
ad7816_show_channel,
|
ad7816_store_channel,
|
0);
|
|
static ssize_t ad7816_show_value(struct device *dev,
|
struct device_attribute *attr,
|
char *buf)
|
{
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
struct ad7816_chip_info *chip = iio_priv(indio_dev);
|
u16 data;
|
s8 value;
|
int ret;
|
|
ret = ad7816_spi_read(chip, &data);
|
if (ret)
|
return -EIO;
|
|
data >>= AD7816_VALUE_OFFSET;
|
|
if (chip->channel_id == 0) {
|
value = (s8)((data >> AD7816_TEMP_FLOAT_OFFSET) - 103);
|
data &= AD7816_TEMP_FLOAT_MASK;
|
if (value < 0)
|
data = BIT(AD7816_TEMP_FLOAT_OFFSET) - data;
|
return sprintf(buf, "%d.%.2d\n", value, data * 25);
|
}
|
return sprintf(buf, "%u\n", data);
|
}
|
|
static IIO_DEVICE_ATTR(value, 0444, ad7816_show_value, NULL, 0);
|
|
static struct attribute *ad7816_attributes[] = {
|
&iio_dev_attr_available_modes.dev_attr.attr,
|
&iio_dev_attr_mode.dev_attr.attr,
|
&iio_dev_attr_channel.dev_attr.attr,
|
&iio_dev_attr_value.dev_attr.attr,
|
NULL,
|
};
|
|
static const struct attribute_group ad7816_attribute_group = {
|
.attrs = ad7816_attributes,
|
};
|
|
/*
|
* temperature bound events
|
*/
|
|
#define IIO_EVENT_CODE_AD7816_OTI IIO_UNMOD_EVENT_CODE(IIO_TEMP, \
|
0, \
|
IIO_EV_TYPE_THRESH, \
|
IIO_EV_DIR_FALLING)
|
|
static irqreturn_t ad7816_event_handler(int irq, void *private)
|
{
|
iio_push_event(private, IIO_EVENT_CODE_AD7816_OTI,
|
iio_get_time_ns(private));
|
return IRQ_HANDLED;
|
}
|
|
static ssize_t ad7816_show_oti(struct device *dev,
|
struct device_attribute *attr,
|
char *buf)
|
{
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
struct ad7816_chip_info *chip = iio_priv(indio_dev);
|
int value;
|
|
if (chip->channel_id > AD7816_CS_MAX) {
|
dev_err(dev, "Invalid oti channel id %d.\n", chip->channel_id);
|
return -EINVAL;
|
} else if (chip->channel_id == 0) {
|
value = AD7816_BOUND_VALUE_MIN +
|
(chip->oti_data[chip->channel_id] -
|
AD7816_BOUND_VALUE_BASE);
|
return sprintf(buf, "%d\n", value);
|
}
|
return sprintf(buf, "%u\n", chip->oti_data[chip->channel_id]);
|
}
|
|
static inline ssize_t ad7816_set_oti(struct device *dev,
|
struct device_attribute *attr,
|
const char *buf,
|
size_t len)
|
{
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
struct ad7816_chip_info *chip = iio_priv(indio_dev);
|
long value;
|
u8 data;
|
int ret;
|
|
ret = kstrtol(buf, 10, &value);
|
if (ret)
|
return ret;
|
|
if (chip->channel_id > AD7816_CS_MAX) {
|
dev_err(dev, "Invalid oti channel id %d.\n", chip->channel_id);
|
return -EINVAL;
|
} else if (chip->channel_id == 0) {
|
if (value < AD7816_BOUND_VALUE_MIN ||
|
value > AD7816_BOUND_VALUE_MAX)
|
return -EINVAL;
|
|
data = (u8)(value - AD7816_BOUND_VALUE_MIN +
|
AD7816_BOUND_VALUE_BASE);
|
} else {
|
if (value < AD7816_BOUND_VALUE_BASE || value > 255)
|
return -EINVAL;
|
|
data = (u8)value;
|
}
|
|
ret = ad7816_spi_write(chip, data);
|
if (ret)
|
return -EIO;
|
|
chip->oti_data[chip->channel_id] = data;
|
|
return len;
|
}
|
|
static IIO_DEVICE_ATTR(oti, 0644,
|
ad7816_show_oti, ad7816_set_oti, 0);
|
|
static struct attribute *ad7816_event_attributes[] = {
|
&iio_dev_attr_oti.dev_attr.attr,
|
NULL,
|
};
|
|
static const struct attribute_group ad7816_event_attribute_group = {
|
.attrs = ad7816_event_attributes,
|
.name = "events",
|
};
|
|
static const struct iio_info ad7816_info = {
|
.attrs = &ad7816_attribute_group,
|
.event_attrs = &ad7816_event_attribute_group,
|
};
|
|
/*
|
* device probe and remove
|
*/
|
|
static int ad7816_probe(struct spi_device *spi_dev)
|
{
|
struct ad7816_chip_info *chip;
|
struct iio_dev *indio_dev;
|
int i, ret;
|
|
indio_dev = devm_iio_device_alloc(&spi_dev->dev, sizeof(*chip));
|
if (!indio_dev)
|
return -ENOMEM;
|
chip = iio_priv(indio_dev);
|
/* this is only used for device removal purposes */
|
dev_set_drvdata(&spi_dev->dev, indio_dev);
|
|
chip->spi_dev = spi_dev;
|
for (i = 0; i <= AD7816_CS_MAX; i++)
|
chip->oti_data[i] = 203;
|
|
chip->id = spi_get_device_id(spi_dev)->driver_data;
|
chip->rdwr_pin = devm_gpiod_get(&spi_dev->dev, "rdwr", GPIOD_OUT_HIGH);
|
if (IS_ERR(chip->rdwr_pin)) {
|
ret = PTR_ERR(chip->rdwr_pin);
|
dev_err(&spi_dev->dev, "Failed to request rdwr GPIO: %d\n",
|
ret);
|
return ret;
|
}
|
chip->convert_pin = devm_gpiod_get(&spi_dev->dev, "convert",
|
GPIOD_OUT_HIGH);
|
if (IS_ERR(chip->convert_pin)) {
|
ret = PTR_ERR(chip->convert_pin);
|
dev_err(&spi_dev->dev, "Failed to request convert GPIO: %d\n",
|
ret);
|
return ret;
|
}
|
if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
|
chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy",
|
GPIOD_IN);
|
if (IS_ERR(chip->busy_pin)) {
|
ret = PTR_ERR(chip->busy_pin);
|
dev_err(&spi_dev->dev, "Failed to request busy GPIO: %d\n",
|
ret);
|
return ret;
|
}
|
}
|
|
indio_dev->name = spi_get_device_id(spi_dev)->name;
|
indio_dev->info = &ad7816_info;
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
if (spi_dev->irq) {
|
/* Only low trigger is supported in ad7816/7/8 */
|
ret = devm_request_threaded_irq(&spi_dev->dev, spi_dev->irq,
|
NULL,
|
&ad7816_event_handler,
|
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
|
indio_dev->name,
|
indio_dev);
|
if (ret)
|
return ret;
|
}
|
|
ret = devm_iio_device_register(&spi_dev->dev, indio_dev);
|
if (ret)
|
return ret;
|
|
dev_info(&spi_dev->dev, "%s temperature sensor and ADC registered.\n",
|
indio_dev->name);
|
|
return 0;
|
}
|
|
static const struct of_device_id ad7816_of_match[] = {
|
{ .compatible = "adi,ad7816", },
|
{ .compatible = "adi,ad7817", },
|
{ .compatible = "adi,ad7818", },
|
{ }
|
};
|
MODULE_DEVICE_TABLE(of, ad7816_of_match);
|
|
static const struct spi_device_id ad7816_id[] = {
|
{ "ad7816", ID_AD7816 },
|
{ "ad7817", ID_AD7817 },
|
{ "ad7818", ID_AD7818 },
|
{}
|
};
|
|
MODULE_DEVICE_TABLE(spi, ad7816_id);
|
|
static struct spi_driver ad7816_driver = {
|
.driver = {
|
.name = "ad7816",
|
.of_match_table = ad7816_of_match,
|
},
|
.probe = ad7816_probe,
|
.id_table = ad7816_id,
|
};
|
module_spi_driver(ad7816_driver);
|
|
MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
|
MODULE_DESCRIPTION("Analog Devices AD7816/7/8 digital temperature sensor driver");
|
MODULE_LICENSE("GPL v2");
|
