/* Texas Instruments TMP102 SMBUS temperature sensor driver * * Copyright 2010 Steven King * * 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 #include #include #include #include #include #include #include #include #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 "); MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); MODULE_LICENSE("GPL");