diff options
Diffstat (limited to 'drivers/hwmon/tmp102.c')
| -rw-r--r-- | drivers/hwmon/tmp102.c | 321 |
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"); |
