|  | /* tmp421.c | 
|  | * | 
|  | * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de> | 
|  | * Preliminary support by: | 
|  | * Melvin Rook, Raymond Ng | 
|  | * | 
|  | * 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., 675 Mass Ave, Cambridge, MA 02139, USA. | 
|  | */ | 
|  |  | 
|  | /* | 
|  | * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC. | 
|  | * Supported models: TMP421, TMP422, TMP423 | 
|  | */ | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/jiffies.h> | 
|  | #include <linux/i2c.h> | 
|  | #include <linux/hwmon.h> | 
|  | #include <linux/hwmon-sysfs.h> | 
|  | #include <linux/err.h> | 
|  | #include <linux/mutex.h> | 
|  | #include <linux/sysfs.h> | 
|  |  | 
|  | /* Addresses to scan */ | 
|  | static unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f, | 
|  | I2C_CLIENT_END }; | 
|  |  | 
|  | enum chips { tmp421, tmp422, tmp423 }; | 
|  |  | 
|  | /* The TMP421 registers */ | 
|  | #define TMP421_CONFIG_REG_1			0x09 | 
|  | #define TMP421_CONVERSION_RATE_REG		0x0B | 
|  | #define TMP421_MANUFACTURER_ID_REG		0xFE | 
|  | #define TMP421_DEVICE_ID_REG			0xFF | 
|  |  | 
|  | static const u8 TMP421_TEMP_MSB[4]		= { 0x00, 0x01, 0x02, 0x03 }; | 
|  | static const u8 TMP421_TEMP_LSB[4]		= { 0x10, 0x11, 0x12, 0x13 }; | 
|  |  | 
|  | /* Flags */ | 
|  | #define TMP421_CONFIG_SHUTDOWN			0x40 | 
|  | #define TMP421_CONFIG_RANGE			0x04 | 
|  |  | 
|  | /* Manufacturer / Device ID's */ | 
|  | #define TMP421_MANUFACTURER_ID			0x55 | 
|  | #define TMP421_DEVICE_ID			0x21 | 
|  | #define TMP422_DEVICE_ID			0x22 | 
|  | #define TMP423_DEVICE_ID			0x23 | 
|  |  | 
|  | static const struct i2c_device_id tmp421_id[] = { | 
|  | { "tmp421", tmp421 }, | 
|  | { "tmp422", tmp422 }, | 
|  | { "tmp423", tmp423 }, | 
|  | { } | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(i2c, tmp421_id); | 
|  |  | 
|  | struct tmp421_data { | 
|  | struct device *hwmon_dev; | 
|  | struct mutex update_lock; | 
|  | char valid; | 
|  | unsigned long last_updated; | 
|  | int kind; | 
|  | u8 config; | 
|  | s16 temp[4]; | 
|  | }; | 
|  |  | 
|  | static int temp_from_s16(s16 reg) | 
|  | { | 
|  | int temp = reg; | 
|  |  | 
|  | return (temp * 1000 + 128) / 256; | 
|  | } | 
|  |  | 
|  | static int temp_from_u16(u16 reg) | 
|  | { | 
|  | int temp = reg; | 
|  |  | 
|  | /* Add offset for extended temperature range. */ | 
|  | temp -= 64 * 256; | 
|  |  | 
|  | return (temp * 1000 + 128) / 256; | 
|  | } | 
|  |  | 
|  | static struct tmp421_data *tmp421_update_device(struct device *dev) | 
|  | { | 
|  | struct i2c_client *client = to_i2c_client(dev); | 
|  | struct tmp421_data *data = i2c_get_clientdata(client); | 
|  | int i; | 
|  |  | 
|  | mutex_lock(&data->update_lock); | 
|  |  | 
|  | if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) { | 
|  | data->config = i2c_smbus_read_byte_data(client, | 
|  | TMP421_CONFIG_REG_1); | 
|  |  | 
|  | for (i = 0; i <= data->kind; i++) { | 
|  | data->temp[i] = i2c_smbus_read_byte_data(client, | 
|  | TMP421_TEMP_MSB[i]) << 8; | 
|  | data->temp[i] |= i2c_smbus_read_byte_data(client, | 
|  | TMP421_TEMP_LSB[i]); | 
|  | } | 
|  | data->last_updated = jiffies; | 
|  | data->valid = 1; | 
|  | } | 
|  |  | 
|  | mutex_unlock(&data->update_lock); | 
|  |  | 
|  | return data; | 
|  | } | 
|  |  | 
|  | static ssize_t show_temp_value(struct device *dev, | 
|  | struct device_attribute *devattr, char *buf) | 
|  | { | 
|  | int index = to_sensor_dev_attr(devattr)->index; | 
|  | struct tmp421_data *data = tmp421_update_device(dev); | 
|  | int temp; | 
|  |  | 
|  | mutex_lock(&data->update_lock); | 
|  | if (data->config & TMP421_CONFIG_RANGE) | 
|  | temp = temp_from_u16(data->temp[index]); | 
|  | else | 
|  | temp = temp_from_s16(data->temp[index]); | 
|  | mutex_unlock(&data->update_lock); | 
|  |  | 
|  | return sprintf(buf, "%d\n", temp); | 
|  | } | 
|  |  | 
|  | static ssize_t show_fault(struct device *dev, | 
|  | struct device_attribute *devattr, char *buf) | 
|  | { | 
|  | int index = to_sensor_dev_attr(devattr)->index; | 
|  | struct tmp421_data *data = tmp421_update_device(dev); | 
|  |  | 
|  | /* | 
|  | * The OPEN bit signals a fault. This is bit 0 of the temperature | 
|  | * register (low byte). | 
|  | */ | 
|  | if (data->temp[index] & 0x01) | 
|  | return sprintf(buf, "1\n"); | 
|  | else | 
|  | return sprintf(buf, "0\n"); | 
|  | } | 
|  |  | 
|  | static mode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a, | 
|  | int n) | 
|  | { | 
|  | struct device *dev = container_of(kobj, struct device, kobj); | 
|  | struct tmp421_data *data = dev_get_drvdata(dev); | 
|  | struct device_attribute *devattr; | 
|  | unsigned int index; | 
|  |  | 
|  | devattr = container_of(a, struct device_attribute, attr); | 
|  | index = to_sensor_dev_attr(devattr)->index; | 
|  |  | 
|  | if (data->kind > index) | 
|  | return a->mode; | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0); | 
|  | static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1); | 
|  | static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1); | 
|  | static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2); | 
|  | static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2); | 
|  | static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3); | 
|  | static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3); | 
|  |  | 
|  | static struct attribute *tmp421_attr[] = { | 
|  | &sensor_dev_attr_temp1_input.dev_attr.attr, | 
|  | &sensor_dev_attr_temp2_input.dev_attr.attr, | 
|  | &sensor_dev_attr_temp2_fault.dev_attr.attr, | 
|  | &sensor_dev_attr_temp3_input.dev_attr.attr, | 
|  | &sensor_dev_attr_temp3_fault.dev_attr.attr, | 
|  | &sensor_dev_attr_temp4_input.dev_attr.attr, | 
|  | &sensor_dev_attr_temp4_fault.dev_attr.attr, | 
|  | NULL | 
|  | }; | 
|  |  | 
|  | static const struct attribute_group tmp421_group = { | 
|  | .attrs = tmp421_attr, | 
|  | .is_visible = tmp421_is_visible, | 
|  | }; | 
|  |  | 
|  | static int tmp421_init_client(struct i2c_client *client) | 
|  | { | 
|  | int config, config_orig; | 
|  |  | 
|  | /* Set the conversion rate to 2 Hz */ | 
|  | i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05); | 
|  |  | 
|  | /* Start conversions (disable shutdown if necessary) */ | 
|  | config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1); | 
|  | if (config < 0) { | 
|  | dev_err(&client->dev, "Could not read configuration" | 
|  | " register (%d)\n", config); | 
|  | return -ENODEV; | 
|  | } | 
|  |  | 
|  | config_orig = config; | 
|  | config &= ~TMP421_CONFIG_SHUTDOWN; | 
|  |  | 
|  | if (config != config_orig) { | 
|  | dev_info(&client->dev, "Enable monitoring chip\n"); | 
|  | i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config); | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int tmp421_detect(struct i2c_client *client, | 
|  | struct i2c_board_info *info) | 
|  | { | 
|  | enum chips kind; | 
|  | struct i2c_adapter *adapter = client->adapter; | 
|  | const char *names[] = { "TMP421", "TMP422", "TMP423" }; | 
|  | u8 reg; | 
|  |  | 
|  | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | 
|  | return -ENODEV; | 
|  |  | 
|  | reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG); | 
|  | if (reg != TMP421_MANUFACTURER_ID) | 
|  | return -ENODEV; | 
|  |  | 
|  | reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG); | 
|  | switch (reg) { | 
|  | case TMP421_DEVICE_ID: | 
|  | kind = tmp421; | 
|  | break; | 
|  | case TMP422_DEVICE_ID: | 
|  | kind = tmp422; | 
|  | break; | 
|  | case TMP423_DEVICE_ID: | 
|  | kind = tmp423; | 
|  | break; | 
|  | default: | 
|  | return -ENODEV; | 
|  | } | 
|  |  | 
|  | strlcpy(info->type, tmp421_id[kind - 1].name, I2C_NAME_SIZE); | 
|  | dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n", | 
|  | names[kind - 1], client->addr); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int tmp421_probe(struct i2c_client *client, | 
|  | const struct i2c_device_id *id) | 
|  | { | 
|  | struct tmp421_data *data; | 
|  | int err; | 
|  |  | 
|  | data = kzalloc(sizeof(struct tmp421_data), GFP_KERNEL); | 
|  | if (!data) | 
|  | return -ENOMEM; | 
|  |  | 
|  | i2c_set_clientdata(client, data); | 
|  | mutex_init(&data->update_lock); | 
|  | data->kind = id->driver_data; | 
|  |  | 
|  | err = tmp421_init_client(client); | 
|  | if (err) | 
|  | goto exit_free; | 
|  |  | 
|  | err = sysfs_create_group(&client->dev.kobj, &tmp421_group); | 
|  | if (err) | 
|  | goto exit_free; | 
|  |  | 
|  | data->hwmon_dev = hwmon_device_register(&client->dev); | 
|  | if (IS_ERR(data->hwmon_dev)) { | 
|  | err = PTR_ERR(data->hwmon_dev); | 
|  | data->hwmon_dev = NULL; | 
|  | goto exit_remove; | 
|  | } | 
|  | return 0; | 
|  |  | 
|  | exit_remove: | 
|  | sysfs_remove_group(&client->dev.kobj, &tmp421_group); | 
|  |  | 
|  | exit_free: | 
|  | i2c_set_clientdata(client, NULL); | 
|  | kfree(data); | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static int tmp421_remove(struct i2c_client *client) | 
|  | { | 
|  | struct tmp421_data *data = i2c_get_clientdata(client); | 
|  |  | 
|  | hwmon_device_unregister(data->hwmon_dev); | 
|  | sysfs_remove_group(&client->dev.kobj, &tmp421_group); | 
|  |  | 
|  | i2c_set_clientdata(client, NULL); | 
|  | kfree(data); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static struct i2c_driver tmp421_driver = { | 
|  | .class = I2C_CLASS_HWMON, | 
|  | .driver = { | 
|  | .name	= "tmp421", | 
|  | }, | 
|  | .probe = tmp421_probe, | 
|  | .remove = tmp421_remove, | 
|  | .id_table = tmp421_id, | 
|  | .detect = tmp421_detect, | 
|  | .address_list = normal_i2c, | 
|  | }; | 
|  |  | 
|  | static int __init tmp421_init(void) | 
|  | { | 
|  | return i2c_add_driver(&tmp421_driver); | 
|  | } | 
|  |  | 
|  | static void __exit tmp421_exit(void) | 
|  | { | 
|  | i2c_del_driver(&tmp421_driver); | 
|  | } | 
|  |  | 
|  | MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>"); | 
|  | MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor" | 
|  | " driver"); | 
|  | MODULE_LICENSE("GPL"); | 
|  |  | 
|  | module_init(tmp421_init); | 
|  | module_exit(tmp421_exit); |