/* tmp421.c * * Copyright (C) 2009 Andre Prendel * 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 #include #include #include #include #include #include #include #include #include /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; enum chips { tmp421, tmp422, tmp423 }; /* The TMP421 registers */ #define TMP421_STATUS_REG 0x08 #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", 2 }, { "tmp422", 3 }, { "tmp423", 4 }, { } }; MODULE_DEVICE_TABLE(i2c, tmp421_id); struct tmp421_data { struct i2c_client *client; struct mutex update_lock; char valid; unsigned long last_updated; int channels; u8 config; s16 temp[4]; }; static int temp_from_s16(s16 reg) { /* Mask out status bits */ int temp = reg & ~0xf; return (temp * 1000 + 128) / 256; } static int temp_from_u16(u16 reg) { /* Mask out status bits */ int temp = reg & ~0xf; /* 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 tmp421_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->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->channels; 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 umode_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 (index < data->channels) 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 const struct attribute_group *tmp421_groups[] = { &tmp421_group, NULL }; 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 config; } 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" }; int addr = client->addr; 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_CONVERSION_RATE_REG); if (reg & 0xf8) return -ENODEV; reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG); if (reg & 0x7f) 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: if (addr == 0x2a) return -ENODEV; kind = tmp422; break; case TMP423_DEVICE_ID: if (addr != 0x4c && addr != 0x4d) return -ENODEV; kind = tmp423; break; default: return -ENODEV; } strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE); dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n", names[kind], client->addr); return 0; } static int tmp421_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct device *hwmon_dev; struct tmp421_data *data; int err; data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL); if (!data) return -ENOMEM; mutex_init(&data->update_lock); data->channels = id->driver_data; data->client = client; err = tmp421_init_client(client); if (err) return err; hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, tmp421_groups); return PTR_ERR_OR_ZERO(hwmon_dev); } static struct i2c_driver tmp421_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "tmp421", }, .probe = tmp421_probe, .id_table = tmp421_id, .detect = tmp421_detect, .address_list = normal_i2c, }; module_i2c_driver(tmp421_driver); MODULE_AUTHOR("Andre Prendel "); MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor driver"); MODULE_LICENSE("GPL");