staging: iio: adc: new driver for ADT75 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

@@ -113,3 +113,10 @@ config AD7816
 	help
 	  Say yes here to build support for Analog Devices AD7816/7/8
 	  temperature sensors and ADC.
+
+config ADT75
+	tristate "Analog Devices ADT75 temperature sensor driver"
+	depends on I2C
+	help
+	  Say yes here to build support for Analog Devices ADT75
+	  temperature sensors.

drivers/staging/iio/adc/Makefile

@@ -22,3 +22,4 @@ obj-$(CONFIG_AD7298) += ad7298.o
 obj-$(CONFIG_AD7314) += ad7314.o
 obj-$(CONFIG_AD7745) += ad7745.o
 obj-$(CONFIG_AD7816) += ad7816.o
+obj-$(CONFIG_ADT75) += adt75.o

drivers/staging/iio/adc/adt75.c

+/*
+ * ADT75 digital temperature sensor driver supporting ADT75
+ *
+ * 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/i2c.h>
+#include <linux/rtc.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+
+/*
+ * ADT75 registers definition
+ */
+
+#define ADT75_TEMPERATURE		0
+#define ADT75_CONFIG			1
+#define ADT75_T_HYST			2
+#define ADT75_T_OS			3
+#define ADT75_ONESHOT			4
+
+/*
+ * ADT75 config
+ */
+#define ADT75_PD			0x1
+#define ADT75_OS_INT			0x2
+#define ADT75_OS_POLARITY		0x4
+#define ADT75_FAULT_QUEUE_MASK		0x18
+#define ADT75_FAULT_QUEUE_OFFSET	3
+#define ADT75_SMBUS_ALART		0x8
+
+/*
+ * ADT75 masks
+ */
+#define ADT75_VALUE_SIGN		0x800
+#define ADT75_VALUE_OFFSET		4
+#define ADT75_VALUE_FLOAT_OFFSET	4
+#define ADT75_VALUE_FLOAT_MASK		0xF
+
+
+/*
+ * struct adt75_chip_info - chip specifc information
+ */
+
+struct adt75_chip_info {
+	const char *name;
+	struct i2c_client *client;
+	struct iio_dev *indio_dev;
+	struct work_struct thresh_work;
+	s64 last_timestamp;
+	u8  config;
+};
+
+/*
+ * adt75 register access by I2C
+ */
+
+static int adt75_i2c_read(struct adt75_chip_info *chip, u8 reg, u8 *data)
+{
+	struct i2c_client *client = chip->client;
+	int ret = 0, len;
+
+	ret = i2c_smbus_write_byte(client, reg);
+	if (ret < 0) {
+		dev_err(&client->dev, "I2C read register address error\n");
+		return ret;
+	}
+
+	if (reg == ADT75_CONFIG || reg == ADT75_ONESHOT)
+		len = 1;
+	else
+		len = 2;
+
+	ret = i2c_master_recv(client, data, len);
+	if (ret < 0) {
+		dev_err(&client->dev, "I2C read error\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int adt75_i2c_write(struct adt75_chip_info *chip, u8 reg, u8 data)
+{
+	struct i2c_client *client = chip->client;
+	int ret = 0;
+
+	if (reg == ADT75_CONFIG || reg == ADT75_ONESHOT)
+		ret = i2c_smbus_write_byte_data(client, reg, data);
+	else
+		ret = i2c_smbus_write_word_data(client, reg, data);
+
+	if (ret < 0)
+		dev_err(&client->dev, "I2C write error\n");
+
+	return ret;
+}
+
+static ssize_t adt75_show_mode(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+
+	if (chip->config & ADT75_PD)
+		return sprintf(buf, "power-save\n");
+	else
+		return sprintf(buf, "full\n");
+}
+
+static ssize_t adt75_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 adt75_chip_info *chip = dev_info->dev_data;
+	int ret;
+	u8 config;
+
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & ~ADT75_PD;
+	if (!strcmp(buf, "full"))
+		config |= ADT75_PD;
+
+	ret = adt75_i2c_write(chip, ADT75_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return ret;
+}
+
+static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
+		adt75_show_mode,
+		adt75_store_mode,
+		0);
+
+static ssize_t adt75_show_available_modes(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return sprintf(buf, "full\npower-down\n");
+}
+
+static IIO_DEVICE_ATTR(available_modes, S_IRUGO, adt75_show_available_modes, NULL, 0);
+
+static ssize_t adt75_show_oneshot(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%d\n", !!(chip->config & ADT75_ONESHOT));
+}
+
+static ssize_t adt75_store_oneshot(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	unsigned long data = 0;
+	int ret;
+	u8 config;
+
+	ret = strict_strtoul(buf, 10, &data);
+	if (ret)
+		return -EINVAL;
+
+
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & ~ADT75_ONESHOT;
+	if (data)
+		config |= ADT75_ONESHOT;
+
+	ret = adt75_i2c_write(chip, ADT75_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return ret;
+}
+
+static IIO_DEVICE_ATTR(oneshot, S_IRUGO | S_IWUSR,
+		adt75_show_oneshot,
+		adt75_store_oneshot,
+		0);
+
+static ssize_t adt75_show_value(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	u16 data;
+	char sign = ' ';
+	int ret;
+
+	if (chip->config & ADT75_PD) {
+		dev_err(dev, "Can't read value in power-down mode.\n");
+		return -EIO;
+	}
+
+	if (chip->config & ADT75_ONESHOT) {
+		/* write to active converter */
+		ret = i2c_smbus_write_byte(chip->client, ADT75_ONESHOT);
+		if (ret)
+			return -EIO;
+	}
+
+	ret = adt75_i2c_read(chip, ADT75_TEMPERATURE, (u8 *)&data);
+	if (ret)
+		return -EIO;
+
+	data = swab16(data) >> ADT75_VALUE_OFFSET;
+	if (data & ADT75_VALUE_SIGN) {
+		/* convert supplement to positive value */
+		data = (ADT75_VALUE_SIGN << 1) - data;
+		sign = '-';
+	}
+
+	return sprintf(buf, "%c%d.%.4d\n", sign,
+		(data >> ADT75_VALUE_FLOAT_OFFSET),
+		(data & ADT75_VALUE_FLOAT_MASK) * 625);
+}
+
+static IIO_DEVICE_ATTR(value, S_IRUGO, adt75_show_value, NULL, 0);
+
+static ssize_t adt75_show_name(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	return sprintf(buf, "%s\n", chip->name);
+}
+
+static IIO_DEVICE_ATTR(name, S_IRUGO, adt75_show_name, NULL, 0);
+
+static struct attribute *adt75_attributes[] = {
+	&iio_dev_attr_available_modes.dev_attr.attr,
+	&iio_dev_attr_mode.dev_attr.attr,
+	&iio_dev_attr_oneshot.dev_attr.attr,
+	&iio_dev_attr_value.dev_attr.attr,
+	&iio_dev_attr_name.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group adt75_attribute_group = {
+	.attrs = adt75_attributes,
+};
+
+/*
+ * temperature bound events
+ */
+
+#define IIO_EVENT_CODE_ADT75_OTI    IIO_BUFFER_EVENT_CODE(0)
+
+static void adt75_interrupt_bh(struct work_struct *work_s)
+{
+	struct adt75_chip_info *chip =
+		container_of(work_s, struct adt75_chip_info, thresh_work);
+
+	enable_irq(chip->client->irq);
+
+	iio_push_event(chip->indio_dev, 0,
+			IIO_EVENT_CODE_ADT75_OTI,
+			chip->last_timestamp);
+}
+
+static int adt75_interrupt(struct iio_dev *dev_info,
+		int index,
+		s64 timestamp,
+		int no_test)
+{
+	struct adt75_chip_info *chip = dev_info->dev_data;
+
+	chip->last_timestamp = timestamp;
+	schedule_work(&chip->thresh_work);
+
+	return 0;
+}
+
+IIO_EVENT_SH(adt75, &adt75_interrupt);
+
+static ssize_t adt75_show_oti_mode(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	int ret;
+
+	/* retrive ALART status */
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	if (chip->config & ADT75_OS_INT)
+		return sprintf(buf, "interrupt\n");
+	else
+		return sprintf(buf, "comparator\n");
+}
+
+static ssize_t adt75_set_oti_mode(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	int ret;
+	u8 config;
+
+	/* retrive ALART status */
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & ~ADT75_OS_INT;
+	if (strcmp(buf, "comparator") != 0)
+		config |= ADT75_OS_INT;
+
+	ret = adt75_i2c_write(chip, ADT75_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return ret;
+}
+
+static ssize_t adt75_show_available_oti_modes(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return sprintf(buf, "comparator\ninterrupt\n");
+}
+
+static ssize_t adt75_show_smbus_alart(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	int ret;
+
+	/* retrive ALART status */
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	return sprintf(buf, "%d\n", !!(chip->config & ADT75_SMBUS_ALART));
+}
+
+static ssize_t adt75_set_smbus_alart(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	unsigned long data = 0;
+	int ret;
+	u8 config;
+
+	ret = strict_strtoul(buf, 10, &data);
+	if (ret)
+		return -EINVAL;
+
+	/* retrive ALART status */
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & ~ADT75_SMBUS_ALART;
+	if (data)
+		config |= ADT75_SMBUS_ALART;
+
+	ret = adt75_i2c_write(chip, ADT75_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return ret;
+}
+
+static ssize_t adt75_show_fault_queue(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct adt75_chip_info *chip = dev_info->dev_data;
+	int ret;
+
+	/* retrive ALART status */
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	return sprintf(buf, "%d\n", (chip->config & ADT75_FAULT_QUEUE_MASK) >>
+				ADT75_FAULT_QUEUE_OFFSET);
+}
+
+static ssize_t adt75_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 adt75_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;
+
+	/* retrive ALART status */
+	ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+	if (ret)
+		return -EIO;
+
+	config = chip->config & ~ADT75_FAULT_QUEUE_MASK;
+	config |= (data << ADT75_FAULT_QUEUE_OFFSET);
+	ret = adt75_i2c_write(chip, ADT75_CONFIG, config);
+	if (ret)
+		return -EIO;
+
+	chip->config = config;
+
+	return ret;
+}
+static inline ssize_t adt75_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 adt75_chip_info *chip = dev_info->dev_data;
+	u16 data;
+	char sign = ' ';
+	int ret;
+
+	ret = adt75_i2c_read(chip, bound_reg, (u8 *)&data);
+	if (ret)
+		return -EIO;
+
+	data = swab16(data) >> ADT75_VALUE_OFFSET;
+	if (data & ADT75_VALUE_SIGN) {
+		/* convert supplement to positive value */
+		data = (ADT75_VALUE_SIGN << 1) - data;
+		sign = '-';
+	}
+
+	return sprintf(buf, "%c%d.%.4d\n", sign,
+		(data >> ADT75_VALUE_FLOAT_OFFSET),
+		(data & ADT75_VALUE_FLOAT_MASK) * 625);
+}
+
+static inline ssize_t adt75_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 adt75_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 (len > ADT75_VALUE_FLOAT_OFFSET)
+			len = ADT75_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;
+	data = (data << ADT75_VALUE_FLOAT_OFFSET) | (tmp2 & ADT75_VALUE_FLOAT_MASK);
+	if (tmp1 < 0)
+		/* convert positive value to supplyment */
+		data = (ADT75_VALUE_SIGN << 1) - data;
+	data <<= ADT75_VALUE_OFFSET;
+	data = swab16(data);
+
+	ret = adt75_i2c_write(chip, bound_reg, (u8)data);
+	if (ret)
+		return -EIO;
+
+	return ret;
+}
+
+static ssize_t adt75_show_t_os(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return adt75_show_t_bound(dev, attr,
+			ADT75_T_OS, buf);
+}
+
+static inline ssize_t adt75_set_t_os(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	return adt75_set_t_bound(dev, attr,
+			ADT75_T_OS, buf, len);
+}
+
+static ssize_t adt75_show_t_hyst(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return adt75_show_t_bound(dev, attr,
+			ADT75_T_HYST, buf);
+}
+
+static inline ssize_t adt75_set_t_hyst(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	return adt75_set_t_bound(dev, attr,
+			ADT75_T_HYST, buf, len);
+}
+
+IIO_EVENT_ATTR_SH(oti_mode, iio_event_adt75,
+		adt75_show_oti_mode, adt75_set_oti_mode, 0);
+IIO_EVENT_ATTR_SH(available_oti_modes, iio_event_adt75,
+		adt75_show_available_oti_modes, NULL, 0);
+IIO_EVENT_ATTR_SH(smbus_alart, iio_event_adt75,
+		adt75_show_smbus_alart, adt75_set_smbus_alart, 0);
+IIO_EVENT_ATTR_SH(fault_queue, iio_event_adt75,
+		adt75_show_fault_queue, adt75_set_fault_queue, 0);
+IIO_EVENT_ATTR_SH(t_os, iio_event_adt75,
+		adt75_show_t_os, adt75_set_t_os, 0);
+IIO_EVENT_ATTR_SH(t_hyst, iio_event_adt75,
+		adt75_show_t_hyst, adt75_set_t_hyst, 0);
+
+static struct attribute *adt75_event_attributes[] = {
+	&iio_event_attr_oti_mode.dev_attr.attr,
+	&iio_event_attr_available_oti_modes.dev_attr.attr,
+	&iio_event_attr_smbus_alart.dev_attr.attr,
+	&iio_event_attr_fault_queue.dev_attr.attr,
+	&iio_event_attr_t_os.dev_attr.attr,
+	&iio_event_attr_t_hyst.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group adt75_event_attribute_group = {
+	.attrs = adt75_event_attributes,
+};
+
+/*
+ * device probe and remove
+ */
+
+static int __devinit adt75_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct adt75_chip_info *chip;
+	int ret = 0;
+
+	chip = kzalloc(sizeof(struct adt75_chip_info), GFP_KERNEL);
+
+	if (chip == NULL)
+		return -ENOMEM;
+
+	/* this is only used for device removal purposes */
+	i2c_set_clientdata(client, chip);
+
+	chip->client = client;
+	chip->name = id->name;
+
+	chip->indio_dev = iio_allocate_device();
+	if (chip->indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_free_chip;
+	}
+
+	chip->indio_dev->dev.parent = &client->dev;
+	chip->indio_dev->attrs = &adt75_attribute_group;
+	chip->indio_dev->event_attrs = &adt75_event_attribute_group;
+	chip->indio_dev->dev_data = (void *)chip;
+	chip->indio_dev->driver_module = THIS_MODULE;
+	chip->indio_dev->num_interrupt_lines = 1;
+	chip->indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = iio_device_register(chip->indio_dev);
+	if (ret)
+		goto error_free_dev;
+
+	if (client->irq > 0) {
+		ret = iio_register_interrupt_line(client->irq,
+				chip->indio_dev,
+				0,
+				IRQF_TRIGGER_LOW,
+				chip->name);
+		if (ret)
+			goto error_unreg_dev;
+
+		/*
+		 * The event handler list element refer to iio_event_adt75.
+		 * All event attributes bind to the same event handler.
+		 * So, only register event handler once.
+		 */
+		iio_add_event_to_list(&iio_event_adt75,
+				&chip->indio_dev->interrupts[0]->ev_list);
+
+		INIT_WORK(&chip->thresh_work, adt75_interrupt_bh);
+
+		ret = adt75_i2c_read(chip, ADT75_CONFIG, &chip->config);
+		if (ret) {
+			ret = -EIO;
+			goto error_unreg_irq;
+		}
+
+		/* set irq polarity low level */
+		chip->config &= ~ADT75_OS_POLARITY;
+
+		ret = adt75_i2c_write(chip, ADT75_CONFIG, chip->config);
+		if (ret) {
+			ret = -EIO;
+			goto error_unreg_irq;
+		}
+	}
+
+	dev_info(&client->dev, "%s temperature sensor registered.\n",
+			 id->name);
+
+	return 0;
+error_unreg_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 adt75_remove(struct i2c_client *client)
+{
+	struct adt75_chip_info *chip = i2c_get_clientdata(client);
+	struct iio_dev *indio_dev = chip->indio_dev;
+
+	if (client->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 i2c_device_id adt75_id[] = {
+	{ "adt75", 0 },
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, adt75_id);
+
+static struct i2c_driver adt75_driver = {
+	.driver = {
+		.name = "adt75",
+	},
+	.probe = adt75_probe,
+	.remove = __devexit_p(adt75_remove),
+	.id_table = adt75_id,
+};
+
+static __init int adt75_init(void)
+{
+	return i2c_add_driver(&adt75_driver);
+}
+
+static __exit void adt75_exit(void)
+{
+	i2c_del_driver(&adt75_driver);
+}
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADT75 digital"
+			" temperature sensor driver");
+MODULE_LICENSE("GPL v2");
+
+module_init(adt75_init);
+module_exit(adt75_exit);