staging: iio: adc: new driver for ADT7310 temperature sensors

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/adc/Kconfig

@@ -120,3 +120,10 @@ config ADT75
 	help
 	  Say yes here to build support for Analog Devices ADT75
 	  temperature sensors.
+
+config ADT7310
+	tristate "Analog Devices ADT7310 temperature sensor driver"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices ADT7310
+	  temperature sensors.

drivers/staging/iio/adc/Makefile

@@ -23,3 +23,4 @@ obj-$(CONFIG_AD7314) += ad7314.o
 obj-$(CONFIG_AD7745) += ad7745.o
 obj-$(CONFIG_AD7816) += ad7816.o
 obj-$(CONFIG_ADT75) += adt75.o
+obj-$(CONFIG_ADT7310) += adt7310.o

drivers/staging/iio/adc/adt7310.c

+/*
+ * ADT7310 digital temperature sensor driver supporting ADT7310
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/workqueue.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/rtc.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+
+/*
+ * ADT7310 registers definition
+ */
+
+#define ADT7310_STATUS			0
+#define ADT7310_CONFIG			1
+#define ADT7310_TEMPERATURE		2
+#define ADT7310_ID			3
+#define ADT7310_T_CRIT			4
+#define ADT7310_T_HYST			5
+#define ADT7310_T_ALARM_HIGH		6
+#define ADT7310_T_ALARM_LOW		7
+
+/*
+ * ADT7310 status
+ */
+#define ADT7310_STAT_T_LOW		0x10
+#define ADT7310_STAT_T_HIGH		0x20
+#define ADT7310_STAT_T_CRIT		0x40
+#define ADT7310_STAT_NOT_RDY		0x80
+
+/*
+ * ADT7310 config
+ */
+#define ADT7310_FAULT_QUEUE_MASK	0x3
+#define ADT7310_CT_POLARITY		0x4
+#define ADT7310_INT_POLARITY		0x8
+#define ADT7310_EVENT_MODE		0x10
+#define ADT7310_MODE_MASK		0x60
+#define ADT7310_ONESHOT			0x20
+#define ADT7310_SPS			0x40
+#define ADT7310_PD			0x60
+#define ADT7310_RESOLUTION		0x80
+
+/*
+ * ADT7310 masks
+ */
+#define ADT7310_T16_VALUE_SIGN			0x8000
+#define ADT7310_T16_VALUE_FLOAT_OFFSET		7
+#define ADT7310_T16_VALUE_FLOAT_MASK		0x7F
+#define ADT7310_T13_VALUE_SIGN			0x1000
+#define ADT7310_T13_VALUE_OFFSET		3
+#define ADT7310_T13_VALUE_FLOAT_OFFSET		4
+#define ADT7310_T13_VALUE_FLOAT_MASK		0xF
+#define ADT7310_T_HYST_MASK			0xF
+#define ADT7310_DEVICE_ID_MASK			0x7
+#define ADT7310_MANUFACTORY_ID_MASK		0xF8
+#define ADT7310_MANUFACTORY_ID_OFFSET		3
+
+
+#define ADT7310_CMD_REG_MASK			0x28
+#define ADT7310_CMD_REG_OFFSET			3
+#define ADT7310_CMD_READ			0x40
+#define ADT7310_CMD_CON_READ			0x4
+
+#define ADT7310_IRQS				2
+
+/*
+ * struct adt7310_chip_info - chip specifc information
+ */
+
+struct adt7310_chip_info {
+	const char *name;
+	struct spi_device *spi_dev;
+	struct iio_dev *indio_dev;
+	struct work_struct thresh_work;
+	s64 last_timestamp;
+	u8  config;
+};
+
+/*
+ * adt7310 register access by SPI
+ */
+
+static int adt7310_spi_read_word(struct adt7310_chip_info *chip, u8 reg, u16 *data)
+{
+	struct spi_device *spi_dev = chip->spi_dev;
+	u8 command = (reg << ADT7310_CMD_REG_OFFSET) & ADT7310_CMD_REG_MASK;
+	int ret = 0;
+
+	command |= ADT7310_CMD_READ;
+	ret = spi_write(spi_dev, &command, sizeof(command));
+	if (ret < 0) {
+		dev_err(&spi_dev->dev, "SPI write command error\n");
+		return ret;
+	}
+
+	ret = spi_read(spi_dev, (u8 *)data, sizeof(*data));
+	if (ret < 0) {
+		dev_err(&spi_dev->dev, "SPI read word error\n");
+		return ret;
+	}
+
+	*data = be16_to_cpu(*data);
+
+	return 0;
+}
+
+static int adt7310_spi_write_word(struct adt7310_chip_info *chip, u8 reg, u16 data)
+{
+	struct spi_device *spi_dev = chip->spi_dev;
+	u8 buf[3];
+	int ret = 0;
+
+	buf[0] = (reg << ADT7310_CMD_REG_OFFSET) & ADT7310_CMD_REG_MASK;
+	buf[1] = (u8)(data >> 8);
+	buf[2] = (u8)(data & 0xFF);
+
+	ret = spi_write(spi_dev, buf, 3);
+	if (ret < 0) {
+		dev_err(&spi_dev->dev, "SPI write word error\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int adt7310_spi_read_byte(struct adt7310_chip_info *chip, u8 reg, u8 *data)
+{
+	struct spi_device *spi_dev = chip->spi_dev;
+	u8 command = (reg << ADT7310_CMD_REG_OFFSET) & ADT7310_CMD_REG_MASK;
+	int ret = 0;
+
+	command |= ADT7310_CMD_READ;
+	ret = spi_write(spi_dev, &command, sizeof(command));
+	if (ret < 0) {
+		dev_err(&spi_dev->dev, "SPI write command error\n");
+		return ret;
+	}
+
+	ret = spi_read(spi_dev, data, sizeof(*data));
+	if (ret < 0) {
+		dev_err(&spi_dev->dev, "SPI read byte error\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int adt7310_spi_write_byte(struct adt7310_chip_info *chip, u8 reg, u8 data)
+{
+	struct spi_device *spi_dev = chip->spi_dev;
+	u8 buf[2];
+	int ret = 0;
+
+	buf[0] = (reg << ADT7310_CMD_REG_OFFSET) & ADT7310_CMD_REG_MASK;
+	buf[1] = data;
+
+	ret = spi_write(spi_dev, buf, 2);
+	if (ret < 0) {
+		dev_err(&spi_dev->dev, "SPI write byte error\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static ssize_t adt7310_show_mode(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	u8 config;
+
+	config = chip->config & ADT7310_MODE_MASK;
+
+	switch (config) {
+	case ADT7310_PD:
+		return sprintf(buf, "power-down\n");
+	case ADT7310_ONESHOT:
+		return sprintf(buf, "one-shot\n");
+	case ADT7310_SPS:
+		return sprintf(buf, "sps\n");
+	default:
+		return sprintf(buf, "full\n");
+	}
+}
+
+static ssize_t adt7310_store_mode(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	u16 config;
+	int ret;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & (~ADT7310_MODE_MASK);
+	if (strcmp(buf, "power-down"))
+		config |= ADT7310_PD;
+	else if (strcmp(buf, "one-shot"))
+		config |= ADT7310_ONESHOT;
+	else if (strcmp(buf, "sps"))
+		config |= ADT7310_SPS;
+
+	ret = adt7310_spi_write_byte(chip, ADT7310_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
+		adt7310_show_mode,
+		adt7310_store_mode,
+		0);
+
+static ssize_t adt7310_show_available_modes(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return sprintf(buf, "full\none-shot\nsps\npower-down\n");
+}
+
+static IIO_DEVICE_ATTR(available_modes, S_IRUGO, adt7310_show_available_modes, NULL, 0);
+
+static ssize_t adt7310_show_resolution(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	int ret;
+	int bits;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	if (chip->config & ADT7310_RESOLUTION)
+		bits = 16;
+	else
+		bits = 13;
+
+	return sprintf(buf, "%d bits\n", bits);
+}
+
+static ssize_t adt7310_store_resolution(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	u16 config;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+	if (ret)
+		return -EINVAL;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & (~ADT7310_RESOLUTION);
+	if (data)
+		config |= ADT7310_RESOLUTION;
+
+	ret = adt7310_spi_write_byte(chip, ADT7310_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR(resolution, S_IRUGO | S_IWUSR,
+		adt7310_show_resolution,
+		adt7310_store_resolution,
+		0);
+
+static ssize_t adt7310_show_id(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	u8 id;
+	int ret;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_ID, &id);
+	if (ret)
+		return -EIO;
+
+	return sprintf(buf, "device id: 0x%x\nmanufactory id: 0x%x\n",
+			id & ADT7310_DEVICE_ID_MASK,
+			(id & ADT7310_MANUFACTORY_ID_MASK) >> ADT7310_MANUFACTORY_ID_OFFSET);
+}
+
+static IIO_DEVICE_ATTR(id, S_IRUGO | S_IWUSR,
+		adt7310_show_id,
+		NULL,
+		0);
+
+static ssize_t adt7310_convert_temperature(struct adt7310_chip_info *chip,
+		u16 data, char *buf)
+{
+	char sign = ' ';
+
+	if (chip->config & ADT7310_RESOLUTION) {
+		if (data & ADT7310_T16_VALUE_SIGN) {
+			/* convert supplement to positive value */
+			data = (u16)((ADT7310_T16_VALUE_SIGN << 1) - (u32)data);
+			sign = '-';
+		}
+		return sprintf(buf, "%c%d.%.7d\n", sign,
+				(data >> ADT7310_T16_VALUE_FLOAT_OFFSET),
+				(data & ADT7310_T16_VALUE_FLOAT_MASK) * 78125);
+	} else {
+		if (data & ADT7310_T13_VALUE_SIGN) {
+			/* convert supplement to positive value */
+			data >>= ADT7310_T13_VALUE_OFFSET;
+			data = (ADT7310_T13_VALUE_SIGN << 1) - data;
+			sign = '-';
+		}
+		return sprintf(buf, "%c%d.%.4d\n", sign,
+				(data >> ADT7310_T13_VALUE_FLOAT_OFFSET),
+				(data & ADT7310_T13_VALUE_FLOAT_MASK) * 625);
+	}
+}
+
+static ssize_t adt7310_show_value(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	u8 status;
+	u16 data;
+	int ret, i = 0;
+
+	do {
+		ret = adt7310_spi_read_byte(chip, ADT7310_STATUS, &status);
+		if (ret)
+			return -EIO;
+		i++;
+		if (i == 10000)
+			return -EIO;
+	} while (status & ADT7310_STAT_NOT_RDY);
+
+	ret = adt7310_spi_read_word(chip, ADT7310_TEMPERATURE, &data);
+	if (ret)
+		return -EIO;
+
+	return adt7310_convert_temperature(chip, data, buf);
+}
+
+static IIO_DEVICE_ATTR(value, S_IRUGO, adt7310_show_value, NULL, 0);
+
+static ssize_t adt7310_show_name(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	return sprintf(buf, "%s\n", chip->name);
+}
+
+static IIO_DEVICE_ATTR(name, S_IRUGO, adt7310_show_name, NULL, 0);
+
+static struct attribute *adt7310_attributes[] = {
+	&iio_dev_attr_available_modes.dev_attr.attr,
+	&iio_dev_attr_mode.dev_attr.attr,
+	&iio_dev_attr_resolution.dev_attr.attr,
+	&iio_dev_attr_id.dev_attr.attr,
+	&iio_dev_attr_value.dev_attr.attr,
+	&iio_dev_attr_name.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group adt7310_attribute_group = {
+	.attrs = adt7310_attributes,
+};
+
+/*
+ * temperature bound events
+ */
+
+#define IIO_EVENT_CODE_ADT7310_ABOVE_ALARM    IIO_BUFFER_EVENT_CODE(0)
+#define IIO_EVENT_CODE_ADT7310_BELLOW_ALARM   IIO_BUFFER_EVENT_CODE(1)
+#define IIO_EVENT_CODE_ADT7310_ABOVE_CRIT     IIO_BUFFER_EVENT_CODE(2)
+
+static void adt7310_interrupt_bh(struct work_struct *work_s)
+{
+	struct adt7310_chip_info *chip =
+		container_of(work_s, struct adt7310_chip_info, thresh_work);
+	u8 status;
+
+	if (adt7310_spi_read_byte(chip, ADT7310_STATUS, &status))
+		return;
+
+	if (status & ADT7310_STAT_T_HIGH)
+		iio_push_event(chip->indio_dev, 0,
+			IIO_EVENT_CODE_ADT7310_ABOVE_ALARM,
+			chip->last_timestamp);
+	if (status & ADT7310_STAT_T_LOW)
+		iio_push_event(chip->indio_dev, 0,
+			IIO_EVENT_CODE_ADT7310_BELLOW_ALARM,
+			chip->last_timestamp);
+	if (status & ADT7310_STAT_T_CRIT)
+		iio_push_event(chip->indio_dev, 0,
+			IIO_EVENT_CODE_ADT7310_ABOVE_CRIT,
+			chip->last_timestamp);
+}
+
+static int adt7310_interrupt(struct iio_dev *dev_info,
+		int index,
+		s64 timestamp,
+		int no_test)
+{
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+
+	chip->last_timestamp = timestamp;
+	schedule_work(&chip->thresh_work);
+
+	return 0;
+}
+
+IIO_EVENT_SH(adt7310, &adt7310_interrupt);
+IIO_EVENT_SH(adt7310_ct, &adt7310_interrupt);
+
+static ssize_t adt7310_show_event_mode(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	int ret;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	if (chip->config & ADT7310_EVENT_MODE)
+		return sprintf(buf, "interrupt\n");
+	else
+		return sprintf(buf, "comparator\n");
+}
+
+static ssize_t adt7310_set_event_mode(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	u16 config;
+	int ret;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config &= ~ADT7310_EVENT_MODE;
+	if (strcmp(buf, "comparator") != 0)
+		config |= ADT7310_EVENT_MODE;
+
+	ret = adt7310_spi_write_byte(chip, ADT7310_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return len;
+}
+
+static ssize_t adt7310_show_available_event_modes(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return sprintf(buf, "comparator\ninterrupt\n");
+}
+
+static ssize_t adt7310_show_fault_queue(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	int ret;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	return sprintf(buf, "%d\n", chip->config & ADT7310_FAULT_QUEUE_MASK);
+}
+
+static ssize_t adt7310_set_fault_queue(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+	u8 config;
+
+	ret = strict_strtoul(buf, 10, &data);
+	if (ret || data > 3)
+		return -EINVAL;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & ~ADT7310_FAULT_QUEUE_MASK;
+	config |= data;
+	ret = adt7310_spi_write_byte(chip, ADT7310_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return len;
+}
+
+static inline ssize_t adt7310_show_t_bound(struct device *dev,
+		struct device_attribute *attr,
+		u8 bound_reg,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	u16 data;
+	int ret;
+
+	ret = adt7310_spi_read_word(chip, bound_reg, &data);
+	if (ret)
+		return -EIO;
+
+	return adt7310_convert_temperature(chip, data, buf);
+}
+
+static inline ssize_t adt7310_set_t_bound(struct device *dev,
+		struct device_attribute *attr,
+		u8 bound_reg,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	long tmp1, tmp2;
+	u16 data;
+	char *pos;
+	int ret;
+
+	pos = strchr(buf, '.');
+
+	ret = strict_strtol(buf, 10, &tmp1);
+
+	if (ret || tmp1 > 127 || tmp1 < -128)
+		return -EINVAL;
+
+	if (pos) {
+		len = strlen(pos);
+
+		if (chip->config & ADT7310_RESOLUTION) {
+			if (len > ADT7310_T16_VALUE_FLOAT_OFFSET)
+				len = ADT7310_T16_VALUE_FLOAT_OFFSET;
+			pos[len] = 0;
+			ret = strict_strtol(pos, 10, &tmp2);
+
+			if (!ret)
+				tmp2 = (tmp2 / 78125) * 78125;
+		} else {
+			if (len > ADT7310_T13_VALUE_FLOAT_OFFSET)
+				len = ADT7310_T13_VALUE_FLOAT_OFFSET;
+			pos[len] = 0;
+			ret = strict_strtol(pos, 10, &tmp2);
+
+			if (!ret)
+				tmp2 = (tmp2 / 625) * 625;
+		}
+	}
+
+	if (tmp1 < 0)
+		data = (u16)(-tmp1);
+	else
+		data = (u16)tmp1;
+
+	if (chip->config & ADT7310_RESOLUTION) {
+		data = (data << ADT7310_T16_VALUE_FLOAT_OFFSET) |
+			(tmp2 & ADT7310_T16_VALUE_FLOAT_MASK);
+
+		if (tmp1 < 0)
+			/* convert positive value to supplyment */
+			data = (u16)((ADT7310_T16_VALUE_SIGN << 1) - (u32)data);
+	} else {
+		data = (data << ADT7310_T13_VALUE_FLOAT_OFFSET) |
+			(tmp2 & ADT7310_T13_VALUE_FLOAT_MASK);
+
+		if (tmp1 < 0)
+			/* convert positive value to supplyment */
+			data = (ADT7310_T13_VALUE_SIGN << 1) - data;
+		data <<= ADT7310_T13_VALUE_OFFSET;
+	}
+
+	ret = adt7310_spi_write_word(chip, bound_reg, data);
+	if (ret)
+		return -EIO;
+
+	return len;
+}
+
+static ssize_t adt7310_show_t_alarm_high(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return adt7310_show_t_bound(dev, attr,
+			ADT7310_T_ALARM_HIGH, buf);
+}
+
+static inline ssize_t adt7310_set_t_alarm_high(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	return adt7310_set_t_bound(dev, attr,
+			ADT7310_T_ALARM_HIGH, buf, len);
+}
+
+static ssize_t adt7310_show_t_alarm_low(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return adt7310_show_t_bound(dev, attr,
+			ADT7310_T_ALARM_LOW, buf);
+}
+
+static inline ssize_t adt7310_set_t_alarm_low(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	return adt7310_set_t_bound(dev, attr,
+			ADT7310_T_ALARM_LOW, buf, len);
+}
+
+static ssize_t adt7310_show_t_crit(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return adt7310_show_t_bound(dev, attr,
+			ADT7310_T_CRIT, buf);
+}
+
+static inline ssize_t adt7310_set_t_crit(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	return adt7310_set_t_bound(dev, attr,
+			ADT7310_T_CRIT, buf, len);
+}
+
+static ssize_t adt7310_show_t_hyst(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	int ret;
+	u8 t_hyst;
+
+	ret = adt7310_spi_read_byte(chip, ADT7310_T_HYST, &t_hyst);
+	if (ret)
+		return -EIO;
+
+	return sprintf(buf, "%d\n", t_hyst & ADT7310_T_HYST_MASK);
+}
+
+static inline ssize_t adt7310_set_t_hyst(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt7310_chip_info *chip = dev_info->dev_data;
+	int ret;
+	unsigned long data;
+	u8 t_hyst;
+
+	ret = strict_strtol(buf, 10, &data);
+
+	if (ret || data > ADT7310_T_HYST_MASK)
+		return -EINVAL;
+
+	t_hyst = (u8)data;
+
+	ret = adt7310_spi_write_byte(chip, ADT7310_T_HYST, t_hyst);
+	if (ret)
+		return -EIO;
+
+	return len;
+}
+
+IIO_EVENT_ATTR_SH(event_mode, iio_event_adt7310,
+		adt7310_show_event_mode, adt7310_set_event_mode, 0);
+IIO_EVENT_ATTR_SH(available_event_modes, iio_event_adt7310,
+		adt7310_show_available_event_modes, NULL, 0);
+IIO_EVENT_ATTR_SH(fault_queue, iio_event_adt7310,
+		adt7310_show_fault_queue, adt7310_set_fault_queue, 0);
+IIO_EVENT_ATTR_SH(t_alarm_high, iio_event_adt7310,
+		adt7310_show_t_alarm_high, adt7310_set_t_alarm_high, 0);
+IIO_EVENT_ATTR_SH(t_alarm_low, iio_event_adt7310,
+		adt7310_show_t_alarm_low, adt7310_set_t_alarm_low, 0);
+IIO_EVENT_ATTR_SH(t_crit, iio_event_adt7310_ct,
+		adt7310_show_t_crit, adt7310_set_t_crit, 0);
+IIO_EVENT_ATTR_SH(t_hyst, iio_event_adt7310,
+		adt7310_show_t_hyst, adt7310_set_t_hyst, 0);
+
+static struct attribute *adt7310_event_int_attributes[] = {
+	&iio_event_attr_event_mode.dev_attr.attr,
+	&iio_event_attr_available_event_modes.dev_attr.attr,
+	&iio_event_attr_fault_queue.dev_attr.attr,
+	&iio_event_attr_t_alarm_high.dev_attr.attr,
+	&iio_event_attr_t_alarm_low.dev_attr.attr,
+	&iio_event_attr_t_hyst.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute *adt7310_event_ct_attributes[] = {
+	&iio_event_attr_event_mode.dev_attr.attr,
+	&iio_event_attr_available_event_modes.dev_attr.attr,
+	&iio_event_attr_fault_queue.dev_attr.attr,
+	&iio_event_attr_t_crit.dev_attr.attr,
+	&iio_event_attr_t_hyst.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group adt7310_event_attribute_group[ADT7310_IRQS] = {
+	{
+		.attrs = adt7310_event_int_attributes,
+	},
+	{
+		.attrs = adt7310_event_ct_attributes,
+	}
+};
+
+/*
+ * device probe and remove
+ */
+
+static int __devinit adt7310_probe(struct spi_device *spi_dev)
+{
+	struct adt7310_chip_info *chip;
+	int ret = 0;
+	unsigned long *adt7310_platform_data = spi_dev->dev.platform_data;
+	unsigned long irq_flags;
+
+	chip = kzalloc(sizeof(struct adt7310_chip_info), GFP_KERNEL);
+
+	if (chip == NULL)
+		return -ENOMEM;
+
+	/* this is only used for device removal purposes */
+	dev_set_drvdata(&spi_dev->dev, chip);
+
+	chip->spi_dev = spi_dev;
+	chip->name = spi_dev->modalias;
+
+	chip->indio_dev = iio_allocate_device();
+	if (chip->indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_free_chip;
+	}
+
+	chip->indio_dev->dev.parent = &spi_dev->dev;
+	chip->indio_dev->attrs = &adt7310_attribute_group;
+	chip->indio_dev->event_attrs = adt7310_event_attribute_group;
+	chip->indio_dev->dev_data = (void *)chip;
+	chip->indio_dev->driver_module = THIS_MODULE;
+	chip->indio_dev->num_interrupt_lines = ADT7310_IRQS;
+	chip->indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = iio_device_register(chip->indio_dev);
+	if (ret)
+		goto error_free_dev;
+
+	/* CT critcal temperature event. line 0 */
+	if (spi_dev->irq) {
+		if (adt7310_platform_data[2])
+			irq_flags = adt7310_platform_data[2];
+		else
+			irq_flags = IRQF_TRIGGER_LOW;
+		ret = iio_register_interrupt_line(spi_dev->irq,
+				chip->indio_dev,
+				0,
+				irq_flags,
+				chip->name);
+		if (ret)
+			goto error_unreg_dev;
+
+		/*
+		 * The event handler list element refer to iio_event_adt7310.
+		 * All event attributes bind to the same event handler.
+		 * One event handler can only be added to one event list.
+		 */
+		iio_add_event_to_list(&iio_event_adt7310,
+				&chip->indio_dev->interrupts[0]->ev_list);
+	}
+
+	/* INT bound temperature alarm event. line 1 */
+	if (adt7310_platform_data[0]) {
+		ret = iio_register_interrupt_line(adt7310_platform_data[0],
+				chip->indio_dev,
+				1,
+				adt7310_platform_data[1],
+				chip->name);
+		if (ret)
+			goto error_unreg_ct_irq;
+
+		/*
+		 * The event handler list element refer to iio_event_adt7310.
+		 * All event attributes bind to the same event handler.
+		 * One event handler can only be added to one event list.
+		 */
+		iio_add_event_to_list(&iio_event_adt7310_ct,
+				&chip->indio_dev->interrupts[1]->ev_list);
+	}
+
+	if (spi_dev->irq && adt7310_platform_data[0]) {
+		INIT_WORK(&chip->thresh_work, adt7310_interrupt_bh);
+
+		ret = adt7310_spi_read_byte(chip, ADT7310_CONFIG, &chip->config);
+		if (ret) {
+			ret = -EIO;
+			goto error_unreg_int_irq;
+		}
+
+		/* set irq polarity low level */
+		chip->config &= ~ADT7310_CT_POLARITY;
+
+		if (adt7310_platform_data[1] & IRQF_TRIGGER_HIGH)
+			chip->config |= ADT7310_INT_POLARITY;
+		else
+			chip->config &= ~ADT7310_INT_POLARITY;
+
+		ret = adt7310_spi_write_byte(chip, ADT7310_CONFIG, chip->config);
+		if (ret) {
+			ret = -EIO;
+			goto error_unreg_int_irq;
+		}
+	}
+
+	dev_info(&spi_dev->dev, "%s temperature sensor registered.\n",
+			chip->name);
+
+	return 0;
+
+error_unreg_int_irq:
+	iio_unregister_interrupt_line(chip->indio_dev, 1);
+error_unreg_ct_irq:
+	iio_unregister_interrupt_line(chip->indio_dev, 0);
+error_unreg_dev:
+	iio_device_unregister(chip->indio_dev);
+error_free_dev:
+	iio_free_device(chip->indio_dev);
+error_free_chip:
+	kfree(chip);
+
+	return ret;
+}
+
+static int __devexit adt7310_remove(struct spi_device *spi_dev)
+{
+	struct adt7310_chip_info *chip = dev_get_drvdata(&spi_dev->dev);
+	struct iio_dev *indio_dev = chip->indio_dev;
+	unsigned long *adt7310_platform_data = spi_dev->dev.platform_data;
+
+	dev_set_drvdata(&spi_dev->dev, NULL);
+	if (adt7310_platform_data[0])
+		iio_unregister_interrupt_line(indio_dev, 1);
+	if (spi_dev->irq)
+		iio_unregister_interrupt_line(indio_dev, 0);
+	iio_device_unregister(indio_dev);
+	iio_free_device(chip->indio_dev);
+	kfree(chip);
+
+	return 0;
+}
+
+static const struct spi_device_id adt7310_id[] = {
+	{ "adt7310", 0 },
+	{}
+};
+
+MODULE_DEVICE_TABLE(spi, adt7310_id);
+
+static struct spi_driver adt7310_driver = {
+	.driver = {
+		.name = "adt7310",
+		.bus = &spi_bus_type,
+		.owner = THIS_MODULE,
+	},
+	.probe = adt7310_probe,
+	.remove = __devexit_p(adt7310_remove),
+	.id_table = adt7310_id,
+};
+
+static __init int adt7310_init(void)
+{
+	return spi_register_driver(&adt7310_driver);
+}
+
+static __exit void adt7310_exit(void)
+{
+	spi_unregister_driver(&adt7310_driver);
+}
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADT7310 digital"
+			" temperature sensor driver");
+MODULE_LICENSE("GPL v2");
+
+module_init(adt7310_init);
+module_exit(adt7310_exit);