hwmon: Driver for TI TMP102 temperature sensor

Driver for the TI TMP102.

The TI TMP102 is similar to the LM75.  It differs from the LM75 by
having a 16-bit conf register and the temp registers have a minimum
resolution of 12 bits; the extended conf register can select 13-bit
resolution (which this driver does) and also change the update rate
(which this driver currently doesn't use).

[JD: Fix tmp102_exit tag, must be __exit, not __init.]
Signed-off-by: Steven King <sfking@fdwdc.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Documentation/hwmon/tmp102

+Kernel driver tmp102
+====================
+
+Supported chips:
+  * Texas Instruments TMP102
+    Prefix: 'tmp102'
+    Addresses scanned: I2C 0x48 0x49 0x4a 0x4b
+    Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp102.html
+
+Author:
+	Steven King <sfking@fdwdc.com>
+
+Description
+-----------
+
+The Texas Instruments TMP102 implements one temperature sensor.  Limits can be
+set through the Overtemperature Shutdown register and Hysteresis register.  The
+sensor is accurate to 0.5 degrees over the range of -25 to +85 C, and to 1.0
+degrees from -40 to +125 C. Resolution of the sensor is 0.0625 degree.  The
+operating temperature has a minimum of -55 C and a maximum of +150 C.
+
+The TMP102 has a programmable update rate that can select between 8, 4, 1, and
+0.5 Hz. (Currently the driver only supports the default of 4 Hz).
+
+The driver provides the common sysfs-interface for temperatures (see
+/Documentation/hwmon/sysfs-interface under Temperatures).
+

drivers/hwmon/Kconfig

@@ -842,6 +842,16 @@ config SENSORS_THMC50
 	  This driver can also be built as a module.  If so, the module
 	  will be called thmc50.
 
+config SENSORS_TMP102
+	tristate "Texas Instruments TMP102 and compatibles"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for Texas Instruments TMP102
+	  sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tmp102.
+
 config SENSORS_TMP401
 	tristate "Texas Instruments TMP401 and compatibles"
 	depends on I2C && EXPERIMENTAL

drivers/hwmon/Makefile

@@ -91,6 +91,7 @@ obj-$(CONFIG_SENSORS_SMSC47M1)	+= smsc47m1.o
 obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
 obj-$(CONFIG_SENSORS_AMC6821)	+= amc6821.o
 obj-$(CONFIG_SENSORS_THMC50)	+= thmc50.o
+obj-$(CONFIG_SENSORS_TMP102)	+= tmp102.o
 obj-$(CONFIG_SENSORS_TMP401)	+= tmp401.o
 obj-$(CONFIG_SENSORS_TMP421)	+= tmp421.o
 obj-$(CONFIG_SENSORS_VIA_CPUTEMP)+= via-cputemp.o

drivers/hwmon/tmp102.c

+/* Texas Instruments TMP102 SMBUS temperature sensor driver
+ *
+ * Copyright 2010 Steven King <sfking@fdwdc.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+
+#define	DRIVER_NAME "tmp102"
+
+#define	TMP102_TEMP_REG			0x00
+#define	TMP102_CONF_REG			0x01
+/* note: these bit definitions are byte swapped */
+#define		TMP102_CONF_SD		0x0100
+#define		TMP102_CONF_TM		0x0200
+#define		TMP102_CONF_POL		0x0400
+#define		TMP102_CONF_F0		0x0800
+#define		TMP102_CONF_F1		0x1000
+#define		TMP102_CONF_R0		0x2000
+#define		TMP102_CONF_R1		0x4000
+#define		TMP102_CONF_OS		0x8000
+#define		TMP102_CONF_EM		0x0010
+#define		TMP102_CONF_AL		0x0020
+#define		TMP102_CONF_CR0		0x0040
+#define		TMP102_CONF_CR1		0x0080
+#define	TMP102_TLOW_REG			0x02
+#define	TMP102_THIGH_REG		0x03
+
+struct tmp102 {
+	struct device *hwmon_dev;
+	struct mutex lock;
+	unsigned long last_update;
+	int temp[3];
+};
+
+/* the TMP102 registers are big endian so we have to swab16 the values */
+static int tmp102_read_reg(struct i2c_client *client, u8 reg)
+{
+	int result = i2c_smbus_read_word_data(client, reg);
+	return result < 0 ? result : swab16(result);
+}
+
+static int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
+{
+	return i2c_smbus_write_word_data(client, reg, swab16(val));
+}
+
+/* convert left adjusted 13bit TMP102 register value to miliCelsius */
+static int tmp102_reg_to_mC(s16 val)
+{
+	return (val * 1000) / 128;
+}
+
+/* convert miliCelsius to left adjusted 13bit TMP102 register value */
+static u16 tmp102_mC_to_reg(int val)
+{
+	return (val * 128) / 1000;
+}
+
+static const u8 tmp102_reg[] = {
+	TMP102_TEMP_REG,
+	TMP102_TLOW_REG,
+	TMP102_THIGH_REG,
+};
+
+static struct tmp102 *tmp102_update_device(struct i2c_client *client)
+{
+	struct tmp102 *tmp102 = i2c_get_clientdata(client);
+
+	mutex_lock(&tmp102->lock);
+	if (time_after(jiffies, tmp102->last_update + HZ / 4)) {
+		int i;
+		for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
+			int status = tmp102_read_reg(client, tmp102_reg[i]);
+			if (status > -1)
+				tmp102->temp[i] = tmp102_reg_to_mC(status);
+		}
+		tmp102->last_update = jiffies;
+	}
+	mutex_unlock(&tmp102->lock);
+	return tmp102;
+}
+
+static ssize_t tmp102_show_temp(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
+
+	return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
+}
+
+static ssize_t tmp102_set_temp(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tmp102 *tmp102 = i2c_get_clientdata(client);
+	long val;
+	int status = 0;
+
+	if ((strict_strtol(buf, 10, &val) < 0) || (abs(val) > 150000))
+		return -EINVAL;
+	mutex_lock(&tmp102->lock);
+	if (tmp102->temp[sda->index] != val) {
+		tmp102->temp[sda->index] = val;
+		status = tmp102_write_reg(client, tmp102_reg[sda->index],
+					  tmp102_mC_to_reg(val));
+	}
+	mutex_unlock(&tmp102->lock);
+	return status ? : count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
+
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
+			  tmp102_set_temp, 1);
+
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
+			  tmp102_set_temp, 2);
+
+static struct attribute *tmp102_attributes[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group tmp102_attr_group = {
+	.attrs = tmp102_attributes,
+};
+
+#define TMP102_CONFIG  (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
+#define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
+
+static int __devinit tmp102_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
+{
+	struct tmp102 *tmp102;
+	int status;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WORD_DATA)) {
+		dev_dbg(&client->dev, "adapter doesnt support SMBUS\n");
+		return -ENODEV;
+	}
+
+	tmp102 = kzalloc(sizeof(*tmp102), GFP_KERNEL);
+	if (!tmp102) {
+		dev_dbg(&client->dev, "kzalloc failed\n");
+		return -ENOMEM;
+	}
+	i2c_set_clientdata(client, tmp102);
+
+	tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
+	status = tmp102_read_reg(client, TMP102_CONF_REG);
+	if (status < 0) {
+		dev_dbg(&client->dev, "error reading config register\n");
+		goto fail0;
+	}
+	status &= ~TMP102_CONFIG_RD_ONLY;
+	if (status != TMP102_CONFIG) {
+		dev_dbg(&client->dev, "could not verify config settings\n");
+		status = -EIO;
+		goto fail0;
+	}
+	tmp102->last_update = jiffies - HZ;
+	mutex_init(&tmp102->lock);
+
+	status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
+	if (status) {
+		dev_dbg(&client->dev, "could not create sysfs files\n");
+		goto fail0;
+	}
+	tmp102->hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(tmp102->hwmon_dev)) {
+		dev_dbg(&client->dev, "unable to register hwmon device\n");
+		status = PTR_ERR(tmp102->hwmon_dev);
+		goto fail1;
+	}
+
+	dev_info(&client->dev, "initialized\n");
+
+	return 0;
+fail1:
+	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
+fail0:
+	i2c_set_clientdata(client, NULL);
+	kfree(tmp102);
+
+	return 0;
+}
+
+static int __devexit tmp102_remove(struct i2c_client *client)
+{
+	struct tmp102 *tmp102 = i2c_get_clientdata(client);
+
+	/* shutdown the chip */
+	tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
+
+	hwmon_device_unregister(tmp102->hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
+	i2c_set_clientdata(client, NULL);
+	kfree(tmp102);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int tmp102_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
+
+	return 0;
+}
+
+static int tmp102_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
+
+	return 0;
+}
+
+static const struct dev_pm_ops tmp102_dev_pm_ops = {
+	.suspend	= tmp102_suspend,
+	.resume		= tmp102_resume,
+};
+
+#define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
+#else
+#define	TMP102_DEV_PM_OPS NULL
+#endif /* CONFIG_PM */
+
+static const unsigned short normal_i2c[] = {
+	0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END
+};
+
+static const struct i2c_device_id tmp102_id[] = {
+	{ DRIVER_NAME, 0 },
+	{ }
+};
+
+static struct i2c_driver tmp102_driver = {
+	.driver.name	= DRIVER_NAME,
+	.driver.pm	= TMP102_DEV_PM_OPS,
+	.class		= I2C_CLASS_HWMON,
+	.probe		= tmp102_probe,
+	.remove		= __devexit_p(tmp102_remove),
+	.id_table	= tmp102_id,
+	.address_list	= normal_i2c,
+};
+
+static int __init tmp102_init(void)
+{
+	return i2c_add_driver(&tmp102_driver);
+}
+module_init(tmp102_init);
+
+static void __exit tmp102_exit(void)
+{
+	i2c_del_driver(&tmp102_driver);
+}
+module_exit(tmp102_exit);
+
+
+MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
+MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
+MODULE_LICENSE("GPL");