| /* |
| * lm92 - Hardware monitoring driver |
| * Copyright (C) 2005-2008 Jean Delvare <khali@linux-fr.org> |
| * |
| * Based on the lm90 driver, with some ideas taken from the lm_sensors |
| * lm92 driver as well. |
| * |
| * The LM92 is a sensor chip made by National Semiconductor. It reports |
| * its own temperature with a 0.0625 deg resolution and a 0.33 deg |
| * accuracy. Complete datasheet can be obtained from National's website |
| * at: |
| * http://www.national.com/pf/LM/LM92.html |
| * |
| * This driver also supports the MAX6635 sensor chip made by Maxim. |
| * This chip is compatible with the LM92, but has a lesser accuracy |
| * (1.0 deg). Complete datasheet can be obtained from Maxim's website |
| * at: |
| * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074 |
| * |
| * Since the LM92 was the first chipset supported by this driver, most |
| * comments will refer to this chipset, but are actually general and |
| * concern all supported chipsets, unless mentioned otherwise. |
| * |
| * Support could easily be added for the National Semiconductor LM76 |
| * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible |
| * with the LM92. |
| * |
| * 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. |
| */ |
| |
| #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> |
| |
| /* The LM92 and MAX6635 have 2 two-state pins for address selection, |
| resulting in 4 possible addresses. */ |
| static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
| I2C_CLIENT_END }; |
| |
| /* Insmod parameters */ |
| I2C_CLIENT_INSMOD_1(lm92); |
| |
| /* The LM92 registers */ |
| #define LM92_REG_CONFIG 0x01 /* 8-bit, RW */ |
| #define LM92_REG_TEMP 0x00 /* 16-bit, RO */ |
| #define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */ |
| #define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */ |
| #define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */ |
| #define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */ |
| #define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */ |
| |
| /* The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius, |
| left-justified in 16-bit registers. No rounding is done, with such |
| a resolution it's just not worth it. Note that the MAX6635 doesn't |
| make use of the 4 lower bits for limits (i.e. effective resolution |
| for limits is 1 degree Celsius). */ |
| static inline int TEMP_FROM_REG(s16 reg) |
| { |
| return reg / 8 * 625 / 10; |
| } |
| |
| static inline s16 TEMP_TO_REG(int val) |
| { |
| if (val <= -60000) |
| return -60000 * 10 / 625 * 8; |
| if (val >= 160000) |
| return 160000 * 10 / 625 * 8; |
| return val * 10 / 625 * 8; |
| } |
| |
| /* Alarm flags are stored in the 3 LSB of the temperature register */ |
| static inline u8 ALARMS_FROM_REG(s16 reg) |
| { |
| return reg & 0x0007; |
| } |
| |
| /* Driver data (common to all clients) */ |
| static struct i2c_driver lm92_driver; |
| |
| /* Client data (each client gets its own) */ |
| struct lm92_data { |
| struct device *hwmon_dev; |
| struct mutex update_lock; |
| char valid; /* zero until following fields are valid */ |
| unsigned long last_updated; /* in jiffies */ |
| |
| /* registers values */ |
| s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst; |
| }; |
| |
| |
| /* |
| * Sysfs attributes and callback functions |
| */ |
| |
| static struct lm92_data *lm92_update_device(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct lm92_data *data = i2c_get_clientdata(client); |
| |
| mutex_lock(&data->update_lock); |
| |
| if (time_after(jiffies, data->last_updated + HZ) |
| || !data->valid) { |
| dev_dbg(&client->dev, "Updating lm92 data\n"); |
| data->temp1_input = swab16(i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP)); |
| data->temp1_hyst = swab16(i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_HYST)); |
| data->temp1_crit = swab16(i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_CRIT)); |
| data->temp1_min = swab16(i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_LOW)); |
| data->temp1_max = swab16(i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_HIGH)); |
| |
| data->last_updated = jiffies; |
| data->valid = 1; |
| } |
| |
| mutex_unlock(&data->update_lock); |
| |
| return data; |
| } |
| |
| #define show_temp(value) \ |
| static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
| { \ |
| struct lm92_data *data = lm92_update_device(dev); \ |
| return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \ |
| } |
| show_temp(temp1_input); |
| show_temp(temp1_crit); |
| show_temp(temp1_min); |
| show_temp(temp1_max); |
| |
| #define set_temp(value, reg) \ |
| static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \ |
| size_t count) \ |
| { \ |
| struct i2c_client *client = to_i2c_client(dev); \ |
| struct lm92_data *data = i2c_get_clientdata(client); \ |
| long val = simple_strtol(buf, NULL, 10); \ |
| \ |
| mutex_lock(&data->update_lock); \ |
| data->value = TEMP_TO_REG(val); \ |
| i2c_smbus_write_word_data(client, reg, swab16(data->value)); \ |
| mutex_unlock(&data->update_lock); \ |
| return count; \ |
| } |
| set_temp(temp1_crit, LM92_REG_TEMP_CRIT); |
| set_temp(temp1_min, LM92_REG_TEMP_LOW); |
| set_temp(temp1_max, LM92_REG_TEMP_HIGH); |
| |
| static ssize_t show_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct lm92_data *data = lm92_update_device(dev); |
| return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit) |
| - TEMP_FROM_REG(data->temp1_hyst)); |
| } |
| static ssize_t show_temp1_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct lm92_data *data = lm92_update_device(dev); |
| return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max) |
| - TEMP_FROM_REG(data->temp1_hyst)); |
| } |
| static ssize_t show_temp1_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct lm92_data *data = lm92_update_device(dev); |
| return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min) |
| + TEMP_FROM_REG(data->temp1_hyst)); |
| } |
| |
| static ssize_t set_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, |
| size_t count) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct lm92_data *data = i2c_get_clientdata(client); |
| long val = simple_strtol(buf, NULL, 10); |
| |
| mutex_lock(&data->update_lock); |
| data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val; |
| i2c_smbus_write_word_data(client, LM92_REG_TEMP_HYST, |
| swab16(TEMP_TO_REG(data->temp1_hyst))); |
| mutex_unlock(&data->update_lock); |
| return count; |
| } |
| |
| static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct lm92_data *data = lm92_update_device(dev); |
| return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input)); |
| } |
| |
| static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| int bitnr = to_sensor_dev_attr(attr)->index; |
| struct lm92_data *data = lm92_update_device(dev); |
| return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1); |
| } |
| |
| static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL); |
| static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit, |
| set_temp1_crit); |
| static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst, |
| set_temp1_crit_hyst); |
| static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min, |
| set_temp1_min); |
| static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL); |
| static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max, |
| set_temp1_max); |
| static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL); |
| static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); |
| static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
| static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); |
| static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); |
| |
| |
| /* |
| * Detection and registration |
| */ |
| |
| static void lm92_init_client(struct i2c_client *client) |
| { |
| u8 config; |
| |
| /* Start the conversions if needed */ |
| config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); |
| if (config & 0x01) |
| i2c_smbus_write_byte_data(client, LM92_REG_CONFIG, |
| config & 0xFE); |
| } |
| |
| /* The MAX6635 has no identification register, so we have to use tricks |
| to identify it reliably. This is somewhat slow. |
| Note that we do NOT rely on the 2 MSB of the configuration register |
| always reading 0, as suggested by the datasheet, because it was once |
| reported not to be true. */ |
| static int max6635_check(struct i2c_client *client) |
| { |
| u16 temp_low, temp_high, temp_hyst, temp_crit; |
| u8 conf; |
| int i; |
| |
| /* No manufacturer ID register, so a read from this address will |
| always return the last read value. */ |
| temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW); |
| if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low) |
| return 0; |
| temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH); |
| if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high) |
| return 0; |
| |
| /* Limits are stored as integer values (signed, 9-bit). */ |
| if ((temp_low & 0x7f00) || (temp_high & 0x7f00)) |
| return 0; |
| temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST); |
| temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT); |
| if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00)) |
| return 0; |
| |
| /* Registers addresses were found to cycle over 16-byte boundaries. |
| We don't test all registers with all offsets so as to save some |
| reads and time, but this should still be sufficient to dismiss |
| non-MAX6635 chips. */ |
| conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); |
| for (i=16; i<96; i*=2) { |
| if (temp_hyst != i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_HYST + i - 16) |
| || temp_crit != i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_CRIT + i) |
| || temp_low != i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_LOW + i + 16) |
| || temp_high != i2c_smbus_read_word_data(client, |
| LM92_REG_TEMP_HIGH + i + 32) |
| || conf != i2c_smbus_read_byte_data(client, |
| LM92_REG_CONFIG + i)) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static struct attribute *lm92_attributes[] = { |
| &dev_attr_temp1_input.attr, |
| &dev_attr_temp1_crit.attr, |
| &dev_attr_temp1_crit_hyst.attr, |
| &dev_attr_temp1_min.attr, |
| &dev_attr_temp1_min_hyst.attr, |
| &dev_attr_temp1_max.attr, |
| &dev_attr_temp1_max_hyst.attr, |
| &dev_attr_alarms.attr, |
| &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
| &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, |
| &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, |
| NULL |
| }; |
| |
| static const struct attribute_group lm92_group = { |
| .attrs = lm92_attributes, |
| }; |
| |
| /* Return 0 if detection is successful, -ENODEV otherwise */ |
| static int lm92_detect(struct i2c_client *new_client, |
| struct i2c_board_info *info) |
| { |
| struct i2c_adapter *adapter = new_client->adapter; |
| u8 config; |
| u16 man_id; |
| |
| if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
| | I2C_FUNC_SMBUS_WORD_DATA)) |
| return -ENODEV; |
| |
| config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG); |
| man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID); |
| |
| if ((config & 0xe0) == 0x00 && man_id == 0x0180) |
| pr_info("lm92: Found National Semiconductor LM92 chip\n"); |
| else if (max6635_check(new_client)) |
| pr_info("lm92: Found Maxim MAX6635 chip\n"); |
| else |
| return -ENODEV; |
| |
| strlcpy(info->type, "lm92", I2C_NAME_SIZE); |
| |
| return 0; |
| } |
| |
| static int lm92_probe(struct i2c_client *new_client, |
| const struct i2c_device_id *id) |
| { |
| struct lm92_data *data; |
| int err; |
| |
| data = kzalloc(sizeof(struct lm92_data), GFP_KERNEL); |
| if (!data) { |
| err = -ENOMEM; |
| goto exit; |
| } |
| |
| i2c_set_clientdata(new_client, data); |
| data->valid = 0; |
| mutex_init(&data->update_lock); |
| |
| /* Initialize the chipset */ |
| lm92_init_client(new_client); |
| |
| /* Register sysfs hooks */ |
| if ((err = sysfs_create_group(&new_client->dev.kobj, &lm92_group))) |
| goto exit_free; |
| |
| data->hwmon_dev = hwmon_device_register(&new_client->dev); |
| if (IS_ERR(data->hwmon_dev)) { |
| err = PTR_ERR(data->hwmon_dev); |
| goto exit_remove; |
| } |
| |
| return 0; |
| |
| exit_remove: |
| sysfs_remove_group(&new_client->dev.kobj, &lm92_group); |
| exit_free: |
| kfree(data); |
| exit: |
| return err; |
| } |
| |
| static int lm92_remove(struct i2c_client *client) |
| { |
| struct lm92_data *data = i2c_get_clientdata(client); |
| |
| hwmon_device_unregister(data->hwmon_dev); |
| sysfs_remove_group(&client->dev.kobj, &lm92_group); |
| |
| kfree(data); |
| return 0; |
| } |
| |
| |
| /* |
| * Module and driver stuff |
| */ |
| |
| static const struct i2c_device_id lm92_id[] = { |
| { "lm92", lm92 }, |
| /* max6635 could be added here */ |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, lm92_id); |
| |
| static struct i2c_driver lm92_driver = { |
| .class = I2C_CLASS_HWMON, |
| .driver = { |
| .name = "lm92", |
| }, |
| .probe = lm92_probe, |
| .remove = lm92_remove, |
| .id_table = lm92_id, |
| .detect = lm92_detect, |
| .address_list = normal_i2c, |
| }; |
| |
| static int __init sensors_lm92_init(void) |
| { |
| return i2c_add_driver(&lm92_driver); |
| } |
| |
| static void __exit sensors_lm92_exit(void) |
| { |
| i2c_del_driver(&lm92_driver); |
| } |
| |
| MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); |
| MODULE_DESCRIPTION("LM92/MAX6635 driver"); |
| MODULE_LICENSE("GPL"); |
| |
| module_init(sensors_lm92_init); |
| module_exit(sensors_lm92_exit); |