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>

4 files changed, 335 insertions, 0 deletions

diff --git a/Documentation/hwmon/tmp102 b/Documentation/hwmon/tmp102
new file mode 100644
index 000000000000..239dded8539f
--- /dev/null
+++ b/Documentation/hwmon/tmp102
@@ -0,0 +1,27 @@
+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).
+
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 6dddad81281e..6d87892a6639 100644
--- a/drivers/hwmon/Kconfig
+++ b/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
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 9b1364a4bd85..2138ceb1a713 100644
--- a/drivers/hwmon/Makefile
+++ b/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
diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
new file mode 100644
index 000000000000..e4def62c0ebf
--- /dev/null
+++ b/drivers/hwmon/tmp102.c
@@ -0,0 +1,297 @@
+/* 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");