/* * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com> * * The LM95245 is a sensor chip made by National Semiconductors. * It reports up to two temperatures (its own plus an external one). * Complete datasheet can be obtained from National's website at: * http://www.national.com/ds.cgi/LM/LM95245.pdf * * This driver is based on lm95241.c * * 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/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> #define DEVNAME "lm95245" static const unsigned short normal_i2c[] = { 0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END }; /* LM95245 registers */ /* general registers */ #define LM95245_REG_RW_CONFIG1 0x03 #define LM95245_REG_RW_CONVERS_RATE 0x04 #define LM95245_REG_W_ONE_SHOT 0x0F /* diode configuration */ #define LM95245_REG_RW_CONFIG2 0xBF #define LM95245_REG_RW_REMOTE_OFFH 0x11 #define LM95245_REG_RW_REMOTE_OFFL 0x12 /* status registers */ #define LM95245_REG_R_STATUS1 0x02 #define LM95245_REG_R_STATUS2 0x33 /* limit registers */ #define LM95245_REG_RW_REMOTE_OS_LIMIT 0x07 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT 0x20 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT 0x19 #define LM95245_REG_RW_COMMON_HYSTERESIS 0x21 /* temperature signed */ #define LM95245_REG_R_LOCAL_TEMPH_S 0x00 #define LM95245_REG_R_LOCAL_TEMPL_S 0x30 #define LM95245_REG_R_REMOTE_TEMPH_S 0x01 #define LM95245_REG_R_REMOTE_TEMPL_S 0x10 /* temperature unsigned */ #define LM95245_REG_R_REMOTE_TEMPH_U 0x31 #define LM95245_REG_R_REMOTE_TEMPL_U 0x32 /* id registers */ #define LM95245_REG_R_MAN_ID 0xFE #define LM95245_REG_R_CHIP_ID 0xFF /* LM95245 specific bitfields */ #define CFG_STOP 0x40 #define CFG_REMOTE_TCRIT_MASK 0x10 #define CFG_REMOTE_OS_MASK 0x08 #define CFG_LOCAL_TCRIT_MASK 0x04 #define CFG_LOCAL_OS_MASK 0x02 #define CFG2_OS_A0 0x40 #define CFG2_DIODE_FAULT_OS 0x20 #define CFG2_DIODE_FAULT_TCRIT 0x10 #define CFG2_REMOTE_TT 0x08 #define CFG2_REMOTE_FILTER_DIS 0x00 #define CFG2_REMOTE_FILTER_EN 0x06 /* conversation rate in ms */ #define RATE_CR0063 0x00 #define RATE_CR0364 0x01 #define RATE_CR1000 0x02 #define RATE_CR2500 0x03 #define STATUS1_DIODE_FAULT 0x04 #define STATUS1_RTCRIT 0x02 #define STATUS1_LOC 0x01 #define MANUFACTURER_ID 0x01 #define DEFAULT_REVISION 0xB3 static const u8 lm95245_reg_address[] = { LM95245_REG_R_LOCAL_TEMPH_S, LM95245_REG_R_LOCAL_TEMPL_S, LM95245_REG_R_REMOTE_TEMPH_S, LM95245_REG_R_REMOTE_TEMPL_S, LM95245_REG_R_REMOTE_TEMPH_U, LM95245_REG_R_REMOTE_TEMPL_U, LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT, LM95245_REG_RW_REMOTE_TCRIT_LIMIT, LM95245_REG_RW_COMMON_HYSTERESIS, LM95245_REG_R_STATUS1, }; /* Client data (each client gets its own) */ struct lm95245_data { struct device *hwmon_dev; struct mutex update_lock; unsigned long last_updated; /* in jiffies */ unsigned long interval; /* in msecs */ bool valid; /* zero until following fields are valid */ /* registers values */ u8 regs[ARRAY_SIZE(lm95245_reg_address)]; u8 config1, config2; }; /* Conversions */ static int temp_from_reg_unsigned(u8 val_h, u8 val_l) { return val_h * 1000 + val_l * 1000 / 256; } static int temp_from_reg_signed(u8 val_h, u8 val_l) { if (val_h & 0x80) return (val_h - 0x100) * 1000; return temp_from_reg_unsigned(val_h, val_l); } static struct lm95245_data *lm95245_update_device(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct lm95245_data *data = i2c_get_clientdata(client); mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + msecs_to_jiffies(data->interval)) || !data->valid) { int i; dev_dbg(&client->dev, "Updating lm95245 data.\n"); for (i = 0; i < ARRAY_SIZE(lm95245_reg_address); i++) data->regs[i] = i2c_smbus_read_byte_data(client, lm95245_reg_address[i]); data->last_updated = jiffies; data->valid = 1; } mutex_unlock(&data->update_lock); return data; } static unsigned long lm95245_read_conversion_rate(struct i2c_client *client) { int rate; unsigned long interval; rate = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONVERS_RATE); switch (rate) { case RATE_CR0063: interval = 63; break; case RATE_CR0364: interval = 364; break; case RATE_CR1000: interval = 1000; break; case RATE_CR2500: default: interval = 2500; break; } return interval; } static unsigned long lm95245_set_conversion_rate(struct i2c_client *client, unsigned long interval) { int rate; if (interval <= 63) { interval = 63; rate = RATE_CR0063; } else if (interval <= 364) { interval = 364; rate = RATE_CR0364; } else if (interval <= 1000) { interval = 1000; rate = RATE_CR1000; } else { interval = 2500; rate = RATE_CR2500; } i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONVERS_RATE, rate); return interval; } /* Sysfs stuff */ static ssize_t show_input(struct device *dev, struct device_attribute *attr, char *buf) { struct lm95245_data *data = lm95245_update_device(dev); int temp; int index = to_sensor_dev_attr(attr)->index; /* * Index 0 (Local temp) is always signed * Index 2 (Remote temp) has both signed and unsigned data * use signed calculation for remote if signed bit is set */ if (index == 0 || data->regs[index] & 0x80) temp = temp_from_reg_signed(data->regs[index], data->regs[index + 1]); else temp = temp_from_reg_unsigned(data->regs[index + 2], data->regs[index + 3]); return snprintf(buf, PAGE_SIZE - 1, "%d\n", temp); } static ssize_t show_limit(struct device *dev, struct device_attribute *attr, char *buf) { struct lm95245_data *data = lm95245_update_device(dev); int index = to_sensor_dev_attr(attr)->index; return snprintf(buf, PAGE_SIZE - 1, "%d\n", data->regs[index] * 1000); } static ssize_t set_limit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); struct lm95245_data *data = i2c_get_clientdata(client); int index = to_sensor_dev_attr(attr)->index; unsigned long val; if (kstrtoul(buf, 10, &val) < 0) return -EINVAL; val /= 1000; val = clamp_val(val, 0, (index == 6 ? 127 : 255)); mutex_lock(&data->update_lock); data->valid = 0; i2c_smbus_write_byte_data(client, lm95245_reg_address[index], val); mutex_unlock(&data->update_lock); return count; } static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); struct lm95245_data *data = i2c_get_clientdata(client); unsigned long val; if (kstrtoul(buf, 10, &val) < 0) return -EINVAL; val /= 1000; val = clamp_val(val, 0, 31); mutex_lock(&data->update_lock); data->valid = 0; /* shared crit hysteresis */ i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS, val); mutex_unlock(&data->update_lock); return count; } static ssize_t show_type(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); struct lm95245_data *data = i2c_get_clientdata(client); return snprintf(buf, PAGE_SIZE - 1, data->config2 & CFG2_REMOTE_TT ? "1\n" : "2\n"); } static ssize_t set_type(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); struct lm95245_data *data = i2c_get_clientdata(client); unsigned long val; if (kstrtoul(buf, 10, &val) < 0) return -EINVAL; if (val != 1 && val != 2) return -EINVAL; mutex_lock(&data->update_lock); if (val == 1) data->config2 |= CFG2_REMOTE_TT; else data->config2 &= ~CFG2_REMOTE_TT; data->valid = 0; i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2, data->config2); mutex_unlock(&data->update_lock); return count; } static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, char *buf) { struct lm95245_data *data = lm95245_update_device(dev); int index = to_sensor_dev_attr(attr)->index; return snprintf(buf, PAGE_SIZE - 1, "%d\n", !!(data->regs[9] & index)); } static ssize_t show_interval(struct device *dev, struct device_attribute *attr, char *buf) { struct lm95245_data *data = lm95245_update_device(dev); return snprintf(buf, PAGE_SIZE - 1, "%lu\n", data->interval); } static ssize_t set_interval(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); struct lm95245_data *data = i2c_get_clientdata(client); unsigned long val; if (kstrtoul(buf, 10, &val) < 0) return -EINVAL; mutex_lock(&data->update_lock); data->interval = lm95245_set_conversion_rate(client, val); mutex_unlock(&data->update_lock); return count; } static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0); static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit, set_limit, 6); static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_limit, set_crit_hyst, 8); static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, STATUS1_LOC); static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2); static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit, set_limit, 7); static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_limit, set_crit_hyst, 8); static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, STATUS1_RTCRIT); static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type, 0); static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, STATUS1_DIODE_FAULT); static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval, set_interval); static struct attribute *lm95245_attributes[] = { &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_crit_alarm.dev_attr.attr, &sensor_dev_attr_temp2_input.dev_attr.attr, &sensor_dev_attr_temp2_crit.dev_attr.attr, &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr, &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr, &sensor_dev_attr_temp2_type.dev_attr.attr, &sensor_dev_attr_temp2_fault.dev_attr.attr, &dev_attr_update_interval.attr, NULL }; static const struct attribute_group lm95245_group = { .attrs = lm95245_attributes, }; /* Return 0 if detection is successful, -ENODEV otherwise */ static int lm95245_detect(struct i2c_client *new_client, struct i2c_board_info *info) { struct i2c_adapter *adapter = new_client->adapter; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; if (i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID) != MANUFACTURER_ID || i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID) != DEFAULT_REVISION) return -ENODEV; strlcpy(info->type, DEVNAME, I2C_NAME_SIZE); return 0; } static void lm95245_init_client(struct i2c_client *client) { struct lm95245_data *data = i2c_get_clientdata(client); data->valid = 0; data->interval = lm95245_read_conversion_rate(client); data->config1 = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONFIG1); data->config2 = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONFIG2); if (data->config1 & CFG_STOP) { /* Clear the standby bit */ data->config1 &= ~CFG_STOP; i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1, data->config1); } } static int lm95245_probe(struct i2c_client *new_client, const struct i2c_device_id *id) { struct lm95245_data *data; int err; data = devm_kzalloc(&new_client->dev, sizeof(struct lm95245_data), GFP_KERNEL); if (!data) return -ENOMEM; i2c_set_clientdata(new_client, data); mutex_init(&data->update_lock); /* Initialize the LM95245 chip */ lm95245_init_client(new_client); /* Register sysfs hooks */ err = sysfs_create_group(&new_client->dev.kobj, &lm95245_group); if (err) return err; data->hwmon_dev = hwmon_device_register(&new_client->dev); if (IS_ERR(data->hwmon_dev)) { err = PTR_ERR(data->hwmon_dev); goto exit_remove_files; } return 0; exit_remove_files: sysfs_remove_group(&new_client->dev.kobj, &lm95245_group); return err; } static int lm95245_remove(struct i2c_client *client) { struct lm95245_data *data = i2c_get_clientdata(client); hwmon_device_unregister(data->hwmon_dev); sysfs_remove_group(&client->dev.kobj, &lm95245_group); return 0; } /* Driver data (common to all clients) */ static const struct i2c_device_id lm95245_id[] = { { DEVNAME, 0 }, { } }; MODULE_DEVICE_TABLE(i2c, lm95245_id); static struct i2c_driver lm95245_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = DEVNAME, }, .probe = lm95245_probe, .remove = lm95245_remove, .id_table = lm95245_id, .detect = lm95245_detect, .address_list = normal_i2c, }; module_i2c_driver(lm95245_driver); MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); MODULE_DESCRIPTION("LM95245 sensor driver"); MODULE_LICENSE("GPL");