|  | /* 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> | 
|  | #include <linux/jiffies.h> | 
|  | #include <linux/thermal.h> | 
|  | #include <linux/of.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 i2c_client *client; | 
|  | struct device *hwmon_dev; | 
|  | struct thermal_zone_device *tz; | 
|  | struct mutex lock; | 
|  | u16 config_orig; | 
|  | unsigned long last_update; | 
|  | 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 struct tmp102 *tmp102_update_device(struct device *dev) | 
|  | { | 
|  | struct tmp102 *tmp102 = dev_get_drvdata(dev); | 
|  | struct i2c_client *client = tmp102->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 = i2c_smbus_read_word_swapped(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 int tmp102_read_temp(void *dev, long *temp) | 
|  | { | 
|  | struct tmp102 *tmp102 = 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 = 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); | 
|  |  | 
|  | #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 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; | 
|  | } | 
|  | tmp102->config_orig = status; | 
|  | status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, | 
|  | TMP102_CONFIG); | 
|  | if (status < 0) { | 
|  | dev_err(dev, "error writing config register\n"); | 
|  | goto fail_restore_config; | 
|  | } | 
|  | status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); | 
|  | if (status < 0) { | 
|  | dev_err(dev, "error reading config register\n"); | 
|  | goto fail_restore_config; | 
|  | } | 
|  | status &= ~TMP102_CONFIG_RD_ONLY; | 
|  | if (status != TMP102_CONFIG) { | 
|  | dev_err(dev, "config settings did not stick\n"); | 
|  | status = -ENODEV; | 
|  | goto fail_restore_config; | 
|  | } | 
|  | tmp102->last_update = jiffies - HZ; | 
|  | mutex_init(&tmp102->lock); | 
|  |  | 
|  | hwmon_dev = 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"); | 
|  | status = PTR_ERR(hwmon_dev); | 
|  | goto fail_restore_config; | 
|  | } | 
|  | tmp102->hwmon_dev = hwmon_dev; | 
|  | tmp102->tz = thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev, | 
|  | tmp102_read_temp, NULL); | 
|  | if (IS_ERR(tmp102->tz)) | 
|  | tmp102->tz = NULL; | 
|  |  | 
|  | dev_info(dev, "initialized\n"); | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | fail_restore_config: | 
|  | i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, | 
|  | tmp102->config_orig); | 
|  | return status; | 
|  | } | 
|  |  | 
|  | static int tmp102_remove(struct i2c_client *client) | 
|  | { | 
|  | struct tmp102 *tmp102 = i2c_get_clientdata(client); | 
|  |  | 
|  | thermal_zone_of_sensor_unregister(tmp102->hwmon_dev, tmp102->tz); | 
|  | hwmon_device_unregister(tmp102->hwmon_dev); | 
|  |  | 
|  | /* Stop monitoring if device was stopped originally */ | 
|  | if (tmp102->config_orig & TMP102_CONF_SD) { | 
|  | int config; | 
|  |  | 
|  | config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); | 
|  | if (config >= 0) | 
|  | i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, | 
|  | config | TMP102_CONF_SD); | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_PM | 
|  | 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); | 
|  | 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 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		= tmp102_remove, | 
|  | .id_table	= tmp102_id, | 
|  | }; | 
|  |  | 
|  | module_i2c_driver(tmp102_driver); | 
|  |  | 
|  | MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); | 
|  | MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); | 
|  | MODULE_LICENSE("GPL"); |