1 /* 2 ds1621.c - Part of lm_sensors, Linux kernel modules for hardware 3 monitoring 4 Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23 5 based on lm75.c by Frodo Looijaard <frodol@dds.nl> 6 Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with 7 the help of Jean Delvare <khali@linux-fr.org> 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 2 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 22 */ 23 24 #include <linux/module.h> 25 #include <linux/init.h> 26 #include <linux/slab.h> 27 #include <linux/jiffies.h> 28 #include <linux/i2c.h> 29 #include <linux/hwmon.h> 30 #include <linux/hwmon-sysfs.h> 31 #include <linux/err.h> 32 #include <linux/mutex.h> 33 #include <linux/sysfs.h> 34 #include "lm75.h" 35 36 /* Addresses to scan */ 37 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 38 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; 39 40 /* Insmod parameters */ 41 static int polarity = -1; 42 module_param(polarity, int, 0); 43 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 44 45 /* Many DS1621 constants specified below */ 46 /* Config register used for detection */ 47 /* 7 6 5 4 3 2 1 0 */ 48 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ 49 #define DS1621_REG_CONFIG_NVB 0x10 50 #define DS1621_REG_CONFIG_POLARITY 0x02 51 #define DS1621_REG_CONFIG_1SHOT 0x01 52 #define DS1621_REG_CONFIG_DONE 0x80 53 54 /* The DS1621 registers */ 55 static const u8 DS1621_REG_TEMP[3] = { 56 0xAA, /* input, word, RO */ 57 0xA2, /* min, word, RW */ 58 0xA1, /* max, word, RW */ 59 }; 60 #define DS1621_REG_CONF 0xAC /* byte, RW */ 61 #define DS1621_COM_START 0xEE /* no data */ 62 #define DS1621_COM_STOP 0x22 /* no data */ 63 64 /* The DS1621 configuration register */ 65 #define DS1621_ALARM_TEMP_HIGH 0x40 66 #define DS1621_ALARM_TEMP_LOW 0x20 67 68 /* Conversions */ 69 #define ALARMS_FROM_REG(val) ((val) & \ 70 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) 71 72 /* Each client has this additional data */ 73 struct ds1621_data { 74 struct device *hwmon_dev; 75 struct mutex update_lock; 76 char valid; /* !=0 if following fields are valid */ 77 unsigned long last_updated; /* In jiffies */ 78 79 u16 temp[3]; /* Register values, word */ 80 u8 conf; /* Register encoding, combined */ 81 }; 82 83 /* Temperature registers are word-sized. 84 DS1621 uses a high-byte first convention, which is exactly opposite to 85 the SMBus standard. */ 86 static int ds1621_read_temp(struct i2c_client *client, u8 reg) 87 { 88 int ret; 89 90 ret = i2c_smbus_read_word_data(client, reg); 91 if (ret < 0) 92 return ret; 93 return swab16(ret); 94 } 95 96 static int ds1621_write_temp(struct i2c_client *client, u8 reg, u16 value) 97 { 98 return i2c_smbus_write_word_data(client, reg, swab16(value)); 99 } 100 101 static void ds1621_init_client(struct i2c_client *client) 102 { 103 u8 conf, new_conf; 104 105 new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 106 /* switch to continuous conversion mode */ 107 new_conf &= ~DS1621_REG_CONFIG_1SHOT; 108 109 /* setup output polarity */ 110 if (polarity == 0) 111 new_conf &= ~DS1621_REG_CONFIG_POLARITY; 112 else if (polarity == 1) 113 new_conf |= DS1621_REG_CONFIG_POLARITY; 114 115 if (conf != new_conf) 116 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); 117 118 /* start conversion */ 119 i2c_smbus_write_byte(client, DS1621_COM_START); 120 } 121 122 static struct ds1621_data *ds1621_update_client(struct device *dev) 123 { 124 struct i2c_client *client = to_i2c_client(dev); 125 struct ds1621_data *data = i2c_get_clientdata(client); 126 u8 new_conf; 127 128 mutex_lock(&data->update_lock); 129 130 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 131 || !data->valid) { 132 int i; 133 134 dev_dbg(&client->dev, "Starting ds1621 update\n"); 135 136 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 137 138 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 139 data->temp[i] = ds1621_read_temp(client, 140 DS1621_REG_TEMP[i]); 141 142 /* reset alarms if necessary */ 143 new_conf = data->conf; 144 if (data->temp[0] > data->temp[1]) /* input > min */ 145 new_conf &= ~DS1621_ALARM_TEMP_LOW; 146 if (data->temp[0] < data->temp[2]) /* input < max */ 147 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 148 if (data->conf != new_conf) 149 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, 150 new_conf); 151 152 data->last_updated = jiffies; 153 data->valid = 1; 154 } 155 156 mutex_unlock(&data->update_lock); 157 158 return data; 159 } 160 161 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 162 char *buf) 163 { 164 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 165 struct ds1621_data *data = ds1621_update_client(dev); 166 return sprintf(buf, "%d\n", 167 LM75_TEMP_FROM_REG(data->temp[attr->index])); 168 } 169 170 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 171 const char *buf, size_t count) 172 { 173 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 174 struct i2c_client *client = to_i2c_client(dev); 175 struct ds1621_data *data = i2c_get_clientdata(client); 176 u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10)); 177 178 mutex_lock(&data->update_lock); 179 data->temp[attr->index] = val; 180 ds1621_write_temp(client, DS1621_REG_TEMP[attr->index], 181 data->temp[attr->index]); 182 mutex_unlock(&data->update_lock); 183 return count; 184 } 185 186 static ssize_t show_alarms(struct device *dev, struct device_attribute *da, 187 char *buf) 188 { 189 struct ds1621_data *data = ds1621_update_client(dev); 190 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 191 } 192 193 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 194 char *buf) 195 { 196 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 197 struct ds1621_data *data = ds1621_update_client(dev); 198 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 199 } 200 201 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 202 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 203 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 204 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 205 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 206 DS1621_ALARM_TEMP_LOW); 207 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 208 DS1621_ALARM_TEMP_HIGH); 209 210 static struct attribute *ds1621_attributes[] = { 211 &sensor_dev_attr_temp1_input.dev_attr.attr, 212 &sensor_dev_attr_temp1_min.dev_attr.attr, 213 &sensor_dev_attr_temp1_max.dev_attr.attr, 214 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 215 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 216 &dev_attr_alarms.attr, 217 NULL 218 }; 219 220 static const struct attribute_group ds1621_group = { 221 .attrs = ds1621_attributes, 222 }; 223 224 225 /* Return 0 if detection is successful, -ENODEV otherwise */ 226 static int ds1621_detect(struct i2c_client *client, 227 struct i2c_board_info *info) 228 { 229 struct i2c_adapter *adapter = client->adapter; 230 int conf, temp; 231 int i; 232 233 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 234 | I2C_FUNC_SMBUS_WORD_DATA 235 | I2C_FUNC_SMBUS_WRITE_BYTE)) 236 return -ENODEV; 237 238 /* Now, we do the remaining detection. It is lousy. */ 239 /* The NVB bit should be low if no EEPROM write has been requested 240 during the latest 10ms, which is highly improbable in our case. */ 241 conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 242 if (conf < 0 || conf & DS1621_REG_CONFIG_NVB) 243 return -ENODEV; 244 /* The 7 lowest bits of a temperature should always be 0. */ 245 for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) { 246 temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]); 247 if (temp < 0 || (temp & 0x7f00)) 248 return -ENODEV; 249 } 250 251 strlcpy(info->type, "ds1621", I2C_NAME_SIZE); 252 253 return 0; 254 } 255 256 static int ds1621_probe(struct i2c_client *client, 257 const struct i2c_device_id *id) 258 { 259 struct ds1621_data *data; 260 int err; 261 262 data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL); 263 if (!data) { 264 err = -ENOMEM; 265 goto exit; 266 } 267 268 i2c_set_clientdata(client, data); 269 mutex_init(&data->update_lock); 270 271 /* Initialize the DS1621 chip */ 272 ds1621_init_client(client); 273 274 /* Register sysfs hooks */ 275 if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group))) 276 goto exit_free; 277 278 data->hwmon_dev = hwmon_device_register(&client->dev); 279 if (IS_ERR(data->hwmon_dev)) { 280 err = PTR_ERR(data->hwmon_dev); 281 goto exit_remove_files; 282 } 283 284 return 0; 285 286 exit_remove_files: 287 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 288 exit_free: 289 kfree(data); 290 exit: 291 return err; 292 } 293 294 static int ds1621_remove(struct i2c_client *client) 295 { 296 struct ds1621_data *data = i2c_get_clientdata(client); 297 298 hwmon_device_unregister(data->hwmon_dev); 299 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 300 301 kfree(data); 302 303 return 0; 304 } 305 306 static const struct i2c_device_id ds1621_id[] = { 307 { "ds1621", 0 }, 308 { "ds1625", 0 }, 309 { } 310 }; 311 MODULE_DEVICE_TABLE(i2c, ds1621_id); 312 313 /* This is the driver that will be inserted */ 314 static struct i2c_driver ds1621_driver = { 315 .class = I2C_CLASS_HWMON, 316 .driver = { 317 .name = "ds1621", 318 }, 319 .probe = ds1621_probe, 320 .remove = ds1621_remove, 321 .id_table = ds1621_id, 322 .detect = ds1621_detect, 323 .address_list = normal_i2c, 324 }; 325 326 static int __init ds1621_init(void) 327 { 328 return i2c_add_driver(&ds1621_driver); 329 } 330 331 static void __exit ds1621_exit(void) 332 { 333 i2c_del_driver(&ds1621_driver); 334 } 335 336 337 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 338 MODULE_DESCRIPTION("DS1621 driver"); 339 MODULE_LICENSE("GPL"); 340 341 module_init(ds1621_init); 342 module_exit(ds1621_exit); 343