| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * lm92 - Hardware monitoring driver |
| * Copyright (C) 2005-2008 Jean Delvare <jdelvare@suse.de> |
| * |
| * 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. |
| */ |
| |
| #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/jiffies.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 }; |
| enum chips { lm92, max6635 }; |
| |
| /* 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(long val) |
| { |
| val = clamp_val(val, -60000, 160000); |
| 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; |
| } |
| |
| enum temp_index { |
| t_input, |
| t_crit, |
| t_min, |
| t_max, |
| t_hyst, |
| t_num_regs |
| }; |
| |
| static const u8 regs[t_num_regs] = { |
| [t_input] = LM92_REG_TEMP, |
| [t_crit] = LM92_REG_TEMP_CRIT, |
| [t_min] = LM92_REG_TEMP_LOW, |
| [t_max] = LM92_REG_TEMP_HIGH, |
| [t_hyst] = LM92_REG_TEMP_HYST, |
| }; |
| |
| /* Client data (each client gets its own) */ |
| struct lm92_data { |
| struct i2c_client *client; |
| struct mutex update_lock; |
| bool valid; /* false until following fields are valid */ |
| unsigned long last_updated; /* in jiffies */ |
| |
| /* registers values */ |
| s16 temp[t_num_regs]; /* index with enum temp_index */ |
| }; |
| |
| /* |
| * Sysfs attributes and callback functions |
| */ |
| |
| static struct lm92_data *lm92_update_device(struct device *dev) |
| { |
| struct lm92_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 + HZ) || |
| !data->valid) { |
| dev_dbg(&client->dev, "Updating lm92 data\n"); |
| for (i = 0; i < t_num_regs; i++) { |
| data->temp[i] = |
| i2c_smbus_read_word_swapped(client, regs[i]); |
| } |
| data->last_updated = jiffies; |
| data->valid = true; |
| } |
| |
| mutex_unlock(&data->update_lock); |
| |
| return data; |
| } |
| |
| static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, |
| char *buf) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
| struct lm92_data *data = lm92_update_device(dev); |
| |
| return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])); |
| } |
| |
| static ssize_t temp_store(struct device *dev, |
| struct device_attribute *devattr, const char *buf, |
| size_t count) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
| struct lm92_data *data = dev_get_drvdata(dev); |
| struct i2c_client *client = data->client; |
| int nr = attr->index; |
| long val; |
| int err; |
| |
| err = kstrtol(buf, 10, &val); |
| if (err) |
| return err; |
| |
| mutex_lock(&data->update_lock); |
| data->temp[nr] = TEMP_TO_REG(val); |
| i2c_smbus_write_word_swapped(client, regs[nr], data->temp[nr]); |
| mutex_unlock(&data->update_lock); |
| return count; |
| } |
| |
| static ssize_t temp_hyst_show(struct device *dev, |
| struct device_attribute *devattr, char *buf) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
| struct lm92_data *data = lm92_update_device(dev); |
| |
| return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]) |
| - TEMP_FROM_REG(data->temp[t_hyst])); |
| } |
| |
| static ssize_t temp1_min_hyst_show(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->temp[t_min]) |
| + TEMP_FROM_REG(data->temp[t_hyst])); |
| } |
| |
| static ssize_t temp_hyst_store(struct device *dev, |
| struct device_attribute *devattr, |
| const char *buf, size_t count) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
| struct lm92_data *data = dev_get_drvdata(dev); |
| struct i2c_client *client = data->client; |
| long val; |
| int err; |
| |
| err = kstrtol(buf, 10, &val); |
| if (err) |
| return err; |
| |
| val = clamp_val(val, -120000, 220000); |
| mutex_lock(&data->update_lock); |
| data->temp[t_hyst] = |
| TEMP_TO_REG(TEMP_FROM_REG(data->temp[attr->index]) - val); |
| i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST, |
| data->temp[t_hyst]); |
| mutex_unlock(&data->update_lock); |
| return count; |
| } |
| |
| static ssize_t alarms_show(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->temp[t_input])); |
| } |
| |
| static ssize_t alarm_show(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->temp[t_input] >> bitnr) & 1); |
| } |
| |
| static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input); |
| static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, t_crit); |
| static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit); |
| static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, t_min); |
| static DEVICE_ATTR_RO(temp1_min_hyst); |
| static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max); |
| static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max); |
| static DEVICE_ATTR_RO(alarms); |
| static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 2); |
| static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 0); |
| static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 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); |
| } |
| |
| static struct attribute *lm92_attrs[] = { |
| &sensor_dev_attr_temp1_input.dev_attr.attr, |
| &sensor_dev_attr_temp1_crit.dev_attr.attr, |
| &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, |
| &sensor_dev_attr_temp1_min.dev_attr.attr, |
| &dev_attr_temp1_min_hyst.attr, |
| &sensor_dev_attr_temp1_max.dev_attr.attr, |
| &sensor_dev_attr_temp1_max_hyst.dev_attr.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 |
| }; |
| ATTRIBUTE_GROUPS(lm92); |
| |
| /* 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 |
| return -ENODEV; |
| |
| strlcpy(info->type, "lm92", I2C_NAME_SIZE); |
| |
| return 0; |
| } |
| |
| static int lm92_probe(struct i2c_client *new_client) |
| { |
| struct device *hwmon_dev; |
| struct lm92_data *data; |
| |
| data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data), |
| GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| data->client = new_client; |
| mutex_init(&data->update_lock); |
| |
| /* Initialize the chipset */ |
| lm92_init_client(new_client); |
| |
| hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev, |
| new_client->name, |
| data, lm92_groups); |
| return PTR_ERR_OR_ZERO(hwmon_dev); |
| } |
| |
| /* |
| * Module and driver stuff |
| */ |
| |
| static const struct i2c_device_id lm92_id[] = { |
| { "lm92", lm92 }, |
| { "max6635", max6635 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, lm92_id); |
| |
| static struct i2c_driver lm92_driver = { |
| .class = I2C_CLASS_HWMON, |
| .driver = { |
| .name = "lm92", |
| }, |
| .probe_new = lm92_probe, |
| .id_table = lm92_id, |
| .detect = lm92_detect, |
| .address_list = normal_i2c, |
| }; |
| |
| module_i2c_driver(lm92_driver); |
| |
| MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); |
| MODULE_DESCRIPTION("LM92/MAX6635 driver"); |
| MODULE_LICENSE("GPL"); |