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 I2C_CLIENT_INSMOD_1(ds1621); 42 static int polarity = -1; 43 module_param(polarity, int, 0); 44 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 45 46 /* Many DS1621 constants specified below */ 47 /* Config register used for detection */ 48 /* 7 6 5 4 3 2 1 0 */ 49 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ 50 #define DS1621_REG_CONFIG_NVB 0x10 51 #define DS1621_REG_CONFIG_POLARITY 0x02 52 #define DS1621_REG_CONFIG_1SHOT 0x01 53 #define DS1621_REG_CONFIG_DONE 0x80 54 55 /* The DS1621 registers */ 56 static const u8 DS1621_REG_TEMP[3] = { 57 0xAA, /* input, word, RO */ 58 0xA2, /* min, word, RW */ 59 0xA1, /* max, word, RW */ 60 }; 61 #define DS1621_REG_CONF 0xAC /* byte, RW */ 62 #define DS1621_COM_START 0xEE /* no data */ 63 #define DS1621_COM_STOP 0x22 /* no data */ 64 65 /* The DS1621 configuration register */ 66 #define DS1621_ALARM_TEMP_HIGH 0x40 67 #define DS1621_ALARM_TEMP_LOW 0x20 68 69 /* Conversions */ 70 #define ALARMS_FROM_REG(val) ((val) & \ 71 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) 72 73 /* Each client has this additional data */ 74 struct ds1621_data { 75 struct device *hwmon_dev; 76 struct mutex update_lock; 77 char valid; /* !=0 if following fields are valid */ 78 unsigned long last_updated; /* In jiffies */ 79 80 u16 temp[3]; /* Register values, word */ 81 u8 conf; /* Register encoding, combined */ 82 }; 83 84 static int ds1621_probe(struct i2c_client *client, 85 const struct i2c_device_id *id); 86 static int ds1621_detect(struct i2c_client *client, int kind, 87 struct i2c_board_info *info); 88 static void ds1621_init_client(struct i2c_client *client); 89 static int ds1621_remove(struct i2c_client *client); 90 static struct ds1621_data *ds1621_update_client(struct device *dev); 91 92 static const struct i2c_device_id ds1621_id[] = { 93 { "ds1621", ds1621 }, 94 { "ds1625", ds1621 }, 95 { } 96 }; 97 MODULE_DEVICE_TABLE(i2c, ds1621_id); 98 99 /* This is the driver that will be inserted */ 100 static struct i2c_driver ds1621_driver = { 101 .class = I2C_CLASS_HWMON, 102 .driver = { 103 .name = "ds1621", 104 }, 105 .probe = ds1621_probe, 106 .remove = ds1621_remove, 107 .id_table = ds1621_id, 108 .detect = ds1621_detect, 109 .address_data = &addr_data, 110 }; 111 112 /* All registers are word-sized, except for the configuration register. 113 DS1621 uses a high-byte first convention, which is exactly opposite to 114 the SMBus standard. */ 115 static int ds1621_read_value(struct i2c_client *client, u8 reg) 116 { 117 if (reg == DS1621_REG_CONF) 118 return i2c_smbus_read_byte_data(client, reg); 119 else 120 return swab16(i2c_smbus_read_word_data(client, reg)); 121 } 122 123 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) 124 { 125 if (reg == DS1621_REG_CONF) 126 return i2c_smbus_write_byte_data(client, reg, value); 127 else 128 return i2c_smbus_write_word_data(client, reg, swab16(value)); 129 } 130 131 static void ds1621_init_client(struct i2c_client *client) 132 { 133 int reg = ds1621_read_value(client, DS1621_REG_CONF); 134 /* switch to continuous conversion mode */ 135 reg &= ~ DS1621_REG_CONFIG_1SHOT; 136 137 /* setup output polarity */ 138 if (polarity == 0) 139 reg &= ~DS1621_REG_CONFIG_POLARITY; 140 else if (polarity == 1) 141 reg |= DS1621_REG_CONFIG_POLARITY; 142 143 ds1621_write_value(client, DS1621_REG_CONF, reg); 144 145 /* start conversion */ 146 i2c_smbus_write_byte(client, DS1621_COM_START); 147 } 148 149 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 150 char *buf) 151 { 152 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 153 struct ds1621_data *data = ds1621_update_client(dev); 154 return sprintf(buf, "%d\n", 155 LM75_TEMP_FROM_REG(data->temp[attr->index])); 156 } 157 158 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 159 const char *buf, size_t count) 160 { 161 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 162 struct i2c_client *client = to_i2c_client(dev); 163 struct ds1621_data *data = ds1621_update_client(dev); 164 u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10)); 165 166 mutex_lock(&data->update_lock); 167 data->temp[attr->index] = val; 168 ds1621_write_value(client, DS1621_REG_TEMP[attr->index], 169 data->temp[attr->index]); 170 mutex_unlock(&data->update_lock); 171 return count; 172 } 173 174 static ssize_t show_alarms(struct device *dev, struct device_attribute *da, 175 char *buf) 176 { 177 struct ds1621_data *data = ds1621_update_client(dev); 178 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 179 } 180 181 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 182 char *buf) 183 { 184 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 185 struct ds1621_data *data = ds1621_update_client(dev); 186 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 187 } 188 189 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 190 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 191 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 192 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 193 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 194 DS1621_ALARM_TEMP_LOW); 195 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 196 DS1621_ALARM_TEMP_HIGH); 197 198 static struct attribute *ds1621_attributes[] = { 199 &sensor_dev_attr_temp1_input.dev_attr.attr, 200 &sensor_dev_attr_temp1_min.dev_attr.attr, 201 &sensor_dev_attr_temp1_max.dev_attr.attr, 202 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 203 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 204 &dev_attr_alarms.attr, 205 NULL 206 }; 207 208 static const struct attribute_group ds1621_group = { 209 .attrs = ds1621_attributes, 210 }; 211 212 213 /* Return 0 if detection is successful, -ENODEV otherwise */ 214 static int ds1621_detect(struct i2c_client *client, int kind, 215 struct i2c_board_info *info) 216 { 217 struct i2c_adapter *adapter = client->adapter; 218 int conf, temp; 219 int i; 220 221 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 222 | I2C_FUNC_SMBUS_WORD_DATA 223 | I2C_FUNC_SMBUS_WRITE_BYTE)) 224 return -ENODEV; 225 226 /* Now, we do the remaining detection. It is lousy. */ 227 if (kind < 0) { 228 /* The NVB bit should be low if no EEPROM write has been 229 requested during the latest 10ms, which is highly 230 improbable in our case. */ 231 conf = ds1621_read_value(client, DS1621_REG_CONF); 232 if (conf & DS1621_REG_CONFIG_NVB) 233 return -ENODEV; 234 /* The 7 lowest bits of a temperature should always be 0. */ 235 for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) { 236 temp = ds1621_read_value(client, DS1621_REG_TEMP[i]); 237 if (temp & 0x007f) 238 return -ENODEV; 239 } 240 } 241 242 strlcpy(info->type, "ds1621", I2C_NAME_SIZE); 243 244 return 0; 245 } 246 247 static int ds1621_probe(struct i2c_client *client, 248 const struct i2c_device_id *id) 249 { 250 struct ds1621_data *data; 251 int err; 252 253 data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL); 254 if (!data) { 255 err = -ENOMEM; 256 goto exit; 257 } 258 259 i2c_set_clientdata(client, data); 260 mutex_init(&data->update_lock); 261 262 /* Initialize the DS1621 chip */ 263 ds1621_init_client(client); 264 265 /* Register sysfs hooks */ 266 if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group))) 267 goto exit_free; 268 269 data->hwmon_dev = hwmon_device_register(&client->dev); 270 if (IS_ERR(data->hwmon_dev)) { 271 err = PTR_ERR(data->hwmon_dev); 272 goto exit_remove_files; 273 } 274 275 return 0; 276 277 exit_remove_files: 278 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 279 exit_free: 280 kfree(data); 281 exit: 282 return err; 283 } 284 285 static int ds1621_remove(struct i2c_client *client) 286 { 287 struct ds1621_data *data = i2c_get_clientdata(client); 288 289 hwmon_device_unregister(data->hwmon_dev); 290 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 291 292 kfree(data); 293 294 return 0; 295 } 296 297 298 static struct ds1621_data *ds1621_update_client(struct device *dev) 299 { 300 struct i2c_client *client = to_i2c_client(dev); 301 struct ds1621_data *data = i2c_get_clientdata(client); 302 u8 new_conf; 303 304 mutex_lock(&data->update_lock); 305 306 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 307 || !data->valid) { 308 int i; 309 310 dev_dbg(&client->dev, "Starting ds1621 update\n"); 311 312 data->conf = ds1621_read_value(client, DS1621_REG_CONF); 313 314 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 315 data->temp[i] = ds1621_read_value(client, 316 DS1621_REG_TEMP[i]); 317 318 /* reset alarms if necessary */ 319 new_conf = data->conf; 320 if (data->temp[0] > data->temp[1]) /* input > min */ 321 new_conf &= ~DS1621_ALARM_TEMP_LOW; 322 if (data->temp[0] < data->temp[2]) /* input < max */ 323 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 324 if (data->conf != new_conf) 325 ds1621_write_value(client, DS1621_REG_CONF, 326 new_conf); 327 328 data->last_updated = jiffies; 329 data->valid = 1; 330 } 331 332 mutex_unlock(&data->update_lock); 333 334 return data; 335 } 336 337 static int __init ds1621_init(void) 338 { 339 return i2c_add_driver(&ds1621_driver); 340 } 341 342 static void __exit ds1621_exit(void) 343 { 344 i2c_del_driver(&ds1621_driver); 345 } 346 347 348 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 349 MODULE_DESCRIPTION("DS1621 driver"); 350 MODULE_LICENSE("GPL"); 351 352 module_init(ds1621_init); 353 module_exit(ds1621_exit); 354