/* Texas Instruments TMP102 SMBus temperature sensor driver * * Copyright (C) 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. */ #include #include #include #include #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 #define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \ TMP102_CONF_POL | TMP102_CONF_F0 | \ TMP102_CONF_F1 | TMP102_CONF_OS | \ TMP102_CONF_EM | TMP102_CONF_AL | \ TMP102_CONF_CR0 | TMP102_CONF_CR1) #define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \ TMP102_CONF_CR0) #define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \ TMP102_CONF_CR1) #define CONVERSION_TIME_MS 35 /* in milli-seconds */ struct tmp102 { struct i2c_client *client; struct mutex lock; u16 config_orig; unsigned long last_update; unsigned long ready_time; bool valid; int temp[3]; }; /* 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 void tmp102_update_device(struct device *dev) { struct tmp102 *tmp102 = dev_get_drvdata(dev); struct i2c_client *client = tmp102->client; mutex_lock(&tmp102->lock); if (!tmp102->valid || time_after(jiffies, tmp102->last_update + HZ / 3)) { int i; for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) { int status = i2c_smbus_read_word_swapped(client, tmp102_reg[i]); if (status > -1) tmp102->temp[i] = tmp102_reg_to_mC(status); } tmp102->last_update = jiffies; tmp102->valid = true; } mutex_unlock(&tmp102->lock); } static int tmp102_read_temp(void *dev, int *temp) { struct tmp102 *tmp102 = dev_get_drvdata(dev); if (time_before(jiffies, tmp102->ready_time)) { dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); return -EAGAIN; } tmp102_update_device(dev); *temp = tmp102->temp[0]; return 0; } 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 = dev_get_drvdata(dev); if (time_before(jiffies, tmp102->ready_time)) return -EAGAIN; tmp102_update_device(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 tmp102 *tmp102 = dev_get_drvdata(dev); struct i2c_client *client = tmp102->client; long val; int status; if (kstrtol(buf, 10, &val) < 0) return -EINVAL; val = clamp_val(val, -256000, 255000); mutex_lock(&tmp102->lock); tmp102->temp[sda->index] = val; status = i2c_smbus_write_word_swapped(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_attrs[] = { &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 }; ATTRIBUTE_GROUPS(tmp102); static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = { .get_temp = tmp102_read_temp, }; static void tmp102_restore_config(void *data) { struct tmp102 *tmp102 = data; struct i2c_client *client = tmp102->client; i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, tmp102->config_orig); } static int tmp102_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct device *hwmon_dev; struct tmp102 *tmp102; int status; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) { dev_err(dev, "adapter doesn't support SMBus word transactions\n"); return -ENODEV; } tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); if (!tmp102) return -ENOMEM; i2c_set_clientdata(client, tmp102); tmp102->client = client; status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); if (status < 0) { dev_err(dev, "error reading config register\n"); return status; } if ((status & ~TMP102_CONFREG_MASK) != (TMP102_CONF_R0 | TMP102_CONF_R1)) { dev_err(dev, "unexpected config register value\n"); return -ENODEV; } tmp102->config_orig = status; devm_add_action(dev, tmp102_restore_config, tmp102); status &= ~TMP102_CONFIG_CLEAR; status |= TMP102_CONFIG_SET; status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, status); if (status < 0) { dev_err(dev, "error writing config register\n"); return status; } mutex_init(&tmp102->lock); tmp102->ready_time = jiffies; if (tmp102->config_orig & TMP102_CONF_SD) { /* * Mark that we are not ready with data until the first * conversion is complete */ tmp102->ready_time += msecs_to_jiffies(CONVERSION_TIME_MS); } hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, tmp102, tmp102_groups); if (IS_ERR(hwmon_dev)) { dev_dbg(dev, "unable to register hwmon device\n"); return PTR_ERR(hwmon_dev); } devm_thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev, &tmp102_of_thermal_ops); dev_info(dev, "initialized\n"); return 0; } #ifdef CONFIG_PM_SLEEP static int tmp102_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); int config; config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); if (config < 0) return config; config |= TMP102_CONF_SD; return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); } static int tmp102_resume(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct tmp102 *tmp102 = i2c_get_clientdata(client); int config; config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); if (config < 0) return config; tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); config &= ~TMP102_CONF_SD; return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); } #endif /* CONFIG_PM */ static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 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, .id_table = tmp102_id, }; module_i2c_driver(tmp102_driver); MODULE_AUTHOR("Steven King "); MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); MODULE_LICENSE("GPL");