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-rw-r--r--drivers/hwmon/tmp102.c321
1 files changed, 321 insertions, 0 deletions
diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
new file mode 100644
index 0000000..8013895
--- /dev/null
+++ b/drivers/hwmon/tmp102.c
@@ -0,0 +1,321 @@
+/* Texas Instruments TMP102 SMBus temperature sensor driver
+ *
+ * Copyright (C) 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/device.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;
+ u16 config_orig;
+ unsigned long last_update;
+ int temp[3];
+};
+
+/* SMBus specifies low byte first, but the TMP102 returns high byte first,
+ * so we have to swab16 the values */
+static inline 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 inline 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 13-bit TMP102 register value to milliCelsius */
+static inline int tmp102_reg_to_mC(s16 val)
+{
+ return ((val & ~0x01) * 1000) / 128;
+}
+
+/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
+static inline 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 / 3)) {
+ 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;
+
+ if (strict_strtol(buf, 10, &val) < 0)
+ return -EINVAL;
+ val = SENSORS_LIMIT(val, -256000, 255000);
+
+ mutex_lock(&tmp102->lock);
+ 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_WORD_DATA)) {
+ dev_err(&client->dev, "adapter doesnt support SMBus word "
+ "transactions\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);
+
+ status = tmp102_read_reg(client, TMP102_CONF_REG);
+ if (status < 0) {
+ dev_err(&client->dev, "error reading config register\n");
+ goto fail_free;
+ }
+ tmp102->config_orig = status;
+ status = tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
+ if (status < 0) {
+ dev_err(&client->dev, "error writing config register\n");
+ goto fail_restore_config;
+ }
+ status = tmp102_read_reg(client, TMP102_CONF_REG);
+ if (status < 0) {
+ dev_err(&client->dev, "error reading config register\n");
+ goto fail_restore_config;
+ }
+ status &= ~TMP102_CONFIG_RD_ONLY;
+ if (status != TMP102_CONFIG) {
+ dev_err(&client->dev, "config settings did not stick\n");
+ status = -ENODEV;
+ goto fail_restore_config;
+ }
+ 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 fail_restore_config;
+ }
+ 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 fail_remove_sysfs;
+ }
+
+ dev_info(&client->dev, "initialized\n");
+
+ return 0;
+
+fail_remove_sysfs:
+ sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
+fail_restore_config:
+ tmp102_write_reg(client, TMP102_CONF_REG, tmp102->config_orig);
+fail_free:
+ i2c_set_clientdata(client, NULL);
+ kfree(tmp102);
+
+ return status;
+}
+
+static int __devexit tmp102_remove(struct i2c_client *client)
+{
+ struct tmp102 *tmp102 = i2c_get_clientdata(client);
+
+ hwmon_device_unregister(tmp102->hwmon_dev);
+ sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
+
+ /* Stop monitoring if device was stopped originally */
+ if (tmp102->config_orig & TMP102_CONF_SD) {
+ int config;
+
+ config = tmp102_read_reg(client, TMP102_CONF_REG);
+ if (config >= 0)
+ tmp102_write_reg(client, TMP102_CONF_REG,
+ config | TMP102_CONF_SD);
+ }
+
+ 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);
+ int config;
+
+ config = tmp102_read_reg(client, TMP102_CONF_REG);
+ if (config < 0)
+ return config;
+
+ config |= TMP102_CONF_SD;
+ return tmp102_write_reg(client, TMP102_CONF_REG, config);
+}
+
+static int tmp102_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int config;
+
+ config = tmp102_read_reg(client, TMP102_CONF_REG);
+ if (config < 0)
+ return config;
+
+ config &= ~TMP102_CONF_SD;
+ return tmp102_write_reg(client, TMP102_CONF_REG, config);
+}
+
+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 struct i2c_device_id tmp102_id[] = {
+ { "tmp102", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, tmp102_id);
+
+static struct i2c_driver tmp102_driver = {
+ .driver.name = DRIVER_NAME,
+ .driver.pm = TMP102_DEV_PM_OPS,
+ .probe = tmp102_probe,
+ .remove = __devexit_p(tmp102_remove),
+ .id_table = tmp102_id,
+};
+
+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");
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