/* * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware * monitoring * Christian W. Zuckschwerdt 2000-11-23 * based on lm75.c by Frodo Looijaard * Ported to Linux 2.6 by Aurelien Jarno with * the help of Jean Delvare * * The DS1621 device is a digital temperature/thermometer with 9-bit * resolution, a thermal alarm output (Tout), and user-defined minimum * and maximum temperature thresholds (TH and TL). * * The DS1625, DS1631, and DS1721 are pin compatible with the DS1621 and * similar in operation, with slight variations as noted in the device * datasheets (please refer to www.maximintegrated.com for specific * device information). * * Since the DS1621 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. * * 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 #include #include #include #include #include #include #include #include #include #include /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; /* Supported devices */ enum chips { ds1621, ds1625, ds1631, ds1721 }; /* Insmod parameters */ static int polarity = -1; module_param(polarity, int, 0); MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); /* * The Configuration/Status register * * - DS1621: * 7 6 5 4 3 2 1 0 * |Done|THF |TLF |NVB | X | X |POL |1SHOT| * * - DS1625: * 7 6 5 4 3 2 1 0 * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT| * * - DS1631: * 7 6 5 4 3 2 1 0 * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT| * * - DS1721: * 7 6 5 4 3 2 1 0 * |Done| X | X | U | R1 | R0 |POL |1SHOT| * * Where: * - 'X' is Reserved * - 'U' is Undefined */ #define DS1621_REG_CONFIG_NVB 0x10 #define DS1621_REG_CONFIG_RESOL 0x0C #define DS1621_REG_CONFIG_POLARITY 0x02 #define DS1621_REG_CONFIG_1SHOT 0x01 #define DS1621_REG_CONFIG_DONE 0x80 #define DS1621_REG_CONFIG_RESOL_SHIFT 2 /* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */ static const unsigned short ds1721_convrates[] = { 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */ 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */ 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */ 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */ }; #define DS1621_CONVERSION_MAX 750 #define DS1625_CONVERSION_MAX 500 #define DS1621_TEMP_MAX 125000 #define DS1621_TEMP_MIN (-55000) /* The DS1621 temperature registers */ static const u8 DS1621_REG_TEMP[3] = { 0xAA, /* input, word, RO */ 0xA2, /* min, word, RW */ 0xA1, /* max, word, RW */ }; #define DS1621_REG_CONF 0xAC /* byte, RW */ #define DS1621_COM_START 0xEE /* no data */ #define DS1721_COM_START 0x51 /* no data */ #define DS1621_COM_STOP 0x22 /* no data */ /* The DS1621 configuration register */ #define DS1621_ALARM_TEMP_HIGH 0x40 #define DS1621_ALARM_TEMP_LOW 0x20 /* Conversions */ #define ALARMS_FROM_REG(val) ((val) & \ (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) /* Each client has this additional data */ struct ds1621_data { struct device *hwmon_dev; struct mutex update_lock; char valid; /* !=0 if following fields are valid */ unsigned long last_updated; /* In jiffies */ enum chips kind; /* device type */ u16 temp[3]; /* Register values, word */ u8 conf; /* Register encoding, combined */ u16 update_interval; /* Conversion rate in milliseconds */ }; static inline int DS1621_TEMP_FROM_REG(u16 reg) { return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10); } /* * TEMP: 0.001C/bit (-55C to +125C) * REG: * - 1621, 1625: 0.5C/bit * - 1631, 1721: 0.0625C/bit * Assume highest resolution and let the bits fall where they may.. */ static inline u16 DS1621_TEMP_TO_REG(long temp) { int ntemp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX); ntemp += (ntemp < 0 ? -31 : 31); ntemp = DIV_ROUND_CLOSEST(ntemp * 10, 625) << 4; return (u16)ntemp; } static void ds1621_init_client(struct i2c_client *client) { u8 conf, new_conf, sreg, resol; struct ds1621_data *data = i2c_get_clientdata(client); new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); /* switch to continuous conversion mode */ new_conf &= ~DS1621_REG_CONFIG_1SHOT; /* setup output polarity */ if (polarity == 0) new_conf &= ~DS1621_REG_CONFIG_POLARITY; else if (polarity == 1) new_conf |= DS1621_REG_CONFIG_POLARITY; if (conf != new_conf) i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); switch (data->kind) { case ds1625: data->update_interval = DS1625_CONVERSION_MAX; sreg = DS1621_COM_START; break; case ds1631: case ds1721: resol = (new_conf & DS1621_REG_CONFIG_RESOL) >> DS1621_REG_CONFIG_RESOL_SHIFT; data->update_interval = ds1721_convrates[resol]; sreg = DS1721_COM_START; break; default: data->update_interval = DS1621_CONVERSION_MAX; sreg = DS1621_COM_START; break; } /* start conversion */ i2c_smbus_write_byte(client, sreg); } static struct ds1621_data *ds1621_update_client(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct ds1621_data *data = i2c_get_clientdata(client); u8 new_conf; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + data->update_interval) || !data->valid) { int i; dev_dbg(&client->dev, "Starting ds1621 update\n"); data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); for (i = 0; i < ARRAY_SIZE(data->temp); i++) data->temp[i] = i2c_smbus_read_word_swapped(client, DS1621_REG_TEMP[i]); /* reset alarms if necessary */ new_conf = data->conf; if (data->temp[0] > data->temp[1]) /* input > min */ new_conf &= ~DS1621_ALARM_TEMP_LOW; if (data->temp[0] < data->temp[2]) /* input < max */ new_conf &= ~DS1621_ALARM_TEMP_HIGH; if (data->conf != new_conf) i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); data->last_updated = jiffies; data->valid = 1; } mutex_unlock(&data->update_lock); return data; } static ssize_t show_temp(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ds1621_data *data = ds1621_update_client(dev); return sprintf(buf, "%d\n", DS1621_TEMP_FROM_REG(data->temp[attr->index])); } static ssize_t set_temp(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct i2c_client *client = to_i2c_client(dev); struct ds1621_data *data = i2c_get_clientdata(client); long val; int err; err = kstrtol(buf, 10, &val); if (err) return err; mutex_lock(&data->update_lock); data->temp[attr->index] = DS1621_TEMP_TO_REG(val); i2c_smbus_write_word_swapped(client, DS1621_REG_TEMP[attr->index], data->temp[attr->index]); mutex_unlock(&data->update_lock); return count; } static ssize_t show_alarms(struct device *dev, struct device_attribute *da, char *buf) { struct ds1621_data *data = ds1621_update_client(dev); return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); } static ssize_t show_alarm(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ds1621_data *data = ds1621_update_client(dev); return sprintf(buf, "%d\n", !!(data->conf & attr->index)); } static ssize_t show_convrate(struct device *dev, struct device_attribute *da, char *buf) { struct i2c_client *client = to_i2c_client(dev); struct ds1621_data *data = i2c_get_clientdata(client); return scnprintf(buf, PAGE_SIZE, "%hu\n", data->update_interval); } static ssize_t set_convrate(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); struct ds1621_data *data = i2c_get_clientdata(client); unsigned long convrate; s32 err; int resol = 0; err = kstrtoul(buf, 10, &convrate); if (err) return err; /* Convert rate into resolution bits */ while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) && convrate > ds1721_convrates[resol]) resol++; mutex_lock(&data->update_lock); data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); data->conf &= ~DS1621_REG_CONFIG_RESOL; data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT); i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf); data->update_interval = ds1721_convrates[resol]; mutex_unlock(&data->update_lock); return count; } static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_convrate, set_convrate); static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, DS1621_ALARM_TEMP_LOW); static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, DS1621_ALARM_TEMP_HIGH); static struct attribute *ds1621_attributes[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_temp1_min.dev_attr.attr, &sensor_dev_attr_temp1_max.dev_attr.attr, &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, &dev_attr_alarms.attr, &dev_attr_update_interval.attr, NULL }; static umode_t ds1621_attribute_visible(struct kobject *kobj, struct attribute *attr, int index) { struct device *dev = container_of(kobj, struct device, kobj); struct i2c_client *client = to_i2c_client(dev); struct ds1621_data *data = i2c_get_clientdata(client); if (attr == &dev_attr_update_interval.attr) if (data->kind == ds1621 || data->kind == ds1625) /* shhh, we're hiding update_interval */ return 0; return attr->mode; } static const struct attribute_group ds1621_group = { .attrs = ds1621_attributes, .is_visible = ds1621_attribute_visible }; /* Return 0 if detection is successful, -ENODEV otherwise */ static int ds1621_detect(struct i2c_client *client, struct i2c_board_info *info) { struct i2c_adapter *adapter = client->adapter; int conf, temp; int i; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_WRITE_BYTE)) return -ENODEV; /* * Now, we do the remaining detection. It is lousy. * * The NVB bit should be low if no EEPROM write has been requested * during the latest 10ms, which is highly improbable in our case. */ conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); if (conf < 0 || conf & DS1621_REG_CONFIG_NVB) return -ENODEV; /* * The ds1621 & ds1625 use 9-bit resolution, so the 7 lowest bits * of the temperature should always be 0 (NOTE: The other chips * have multi-resolution support, so if they have 9-bit resolution * configured and the min/max temperature values set accordingly, * then if not explicitly instantiated, they *will* appear as and * emulate a ds1621 device). */ for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) { temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]); if (temp < 0 || (temp & 0x7f00)) return -ENODEV; } strlcpy(info->type, "ds1621", I2C_NAME_SIZE); return 0; } static int ds1621_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct ds1621_data *data; int err; data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data), GFP_KERNEL); if (!data) return -ENOMEM; i2c_set_clientdata(client, data); mutex_init(&data->update_lock); data->kind = id->driver_data; /* Initialize the DS1621 chip */ ds1621_init_client(client); /* Register sysfs hooks */ err = sysfs_create_group(&client->dev.kobj, &ds1621_group); if (err) return err; data->hwmon_dev = hwmon_device_register(&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(&client->dev.kobj, &ds1621_group); return err; } static int ds1621_remove(struct i2c_client *client) { struct ds1621_data *data = i2c_get_clientdata(client); hwmon_device_unregister(data->hwmon_dev); sysfs_remove_group(&client->dev.kobj, &ds1621_group); return 0; } static const struct i2c_device_id ds1621_id[] = { { "ds1621", ds1621 }, { "ds1625", ds1625 }, { "ds1631", ds1631 }, { "ds1721", ds1721 }, { } }; MODULE_DEVICE_TABLE(i2c, ds1621_id); /* This is the driver that will be inserted */ static struct i2c_driver ds1621_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "ds1621", }, .probe = ds1621_probe, .remove = ds1621_remove, .id_table = ds1621_id, .detect = ds1621_detect, .address_list = normal_i2c, }; module_i2c_driver(ds1621_driver); MODULE_AUTHOR("Christian W. Zuckschwerdt "); MODULE_DESCRIPTION("DS1621 driver"); MODULE_LICENSE("GPL");