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 /* Temperature registers are word-sized. 85 DS1621 uses a high-byte first convention, which is exactly opposite to 86 the SMBus standard. */ 87 static int ds1621_read_temp(struct i2c_client *client, u8 reg) 88 { 89 int ret; 90 91 ret = i2c_smbus_read_word_data(client, reg); 92 if (ret < 0) 93 return ret; 94 return swab16(ret); 95 } 96 97 static int ds1621_write_temp(struct i2c_client *client, u8 reg, u16 value) 98 { 99 return i2c_smbus_write_word_data(client, reg, swab16(value)); 100 } 101 102 static void ds1621_init_client(struct i2c_client *client) 103 { 104 u8 conf, new_conf; 105 106 new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 107 /* switch to continuous conversion mode */ 108 new_conf &= ~DS1621_REG_CONFIG_1SHOT; 109 110 /* setup output polarity */ 111 if (polarity == 0) 112 new_conf &= ~DS1621_REG_CONFIG_POLARITY; 113 else if (polarity == 1) 114 new_conf |= DS1621_REG_CONFIG_POLARITY; 115 116 if (conf != new_conf) 117 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); 118 119 /* start conversion */ 120 i2c_smbus_write_byte(client, DS1621_COM_START); 121 } 122 123 static struct ds1621_data *ds1621_update_client(struct device *dev) 124 { 125 struct i2c_client *client = to_i2c_client(dev); 126 struct ds1621_data *data = i2c_get_clientdata(client); 127 u8 new_conf; 128 129 mutex_lock(&data->update_lock); 130 131 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 132 || !data->valid) { 133 int i; 134 135 dev_dbg(&client->dev, "Starting ds1621 update\n"); 136 137 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 138 139 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 140 data->temp[i] = ds1621_read_temp(client, 141 DS1621_REG_TEMP[i]); 142 143 /* reset alarms if necessary */ 144 new_conf = data->conf; 145 if (data->temp[0] > data->temp[1]) /* input > min */ 146 new_conf &= ~DS1621_ALARM_TEMP_LOW; 147 if (data->temp[0] < data->temp[2]) /* input < max */ 148 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 149 if (data->conf != new_conf) 150 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, 151 new_conf); 152 153 data->last_updated = jiffies; 154 data->valid = 1; 155 } 156 157 mutex_unlock(&data->update_lock); 158 159 return data; 160 } 161 162 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 163 char *buf) 164 { 165 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 166 struct ds1621_data *data = ds1621_update_client(dev); 167 return sprintf(buf, "%d\n", 168 LM75_TEMP_FROM_REG(data->temp[attr->index])); 169 } 170 171 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 172 const char *buf, size_t count) 173 { 174 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 175 struct i2c_client *client = to_i2c_client(dev); 176 struct ds1621_data *data = i2c_get_clientdata(client); 177 u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10)); 178 179 mutex_lock(&data->update_lock); 180 data->temp[attr->index] = val; 181 ds1621_write_temp(client, DS1621_REG_TEMP[attr->index], 182 data->temp[attr->index]); 183 mutex_unlock(&data->update_lock); 184 return count; 185 } 186 187 static ssize_t show_alarms(struct device *dev, struct device_attribute *da, 188 char *buf) 189 { 190 struct ds1621_data *data = ds1621_update_client(dev); 191 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 192 } 193 194 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 195 char *buf) 196 { 197 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 198 struct ds1621_data *data = ds1621_update_client(dev); 199 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 200 } 201 202 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 203 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 204 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 205 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 206 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 207 DS1621_ALARM_TEMP_LOW); 208 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 209 DS1621_ALARM_TEMP_HIGH); 210 211 static struct attribute *ds1621_attributes[] = { 212 &sensor_dev_attr_temp1_input.dev_attr.attr, 213 &sensor_dev_attr_temp1_min.dev_attr.attr, 214 &sensor_dev_attr_temp1_max.dev_attr.attr, 215 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 216 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 217 &dev_attr_alarms.attr, 218 NULL 219 }; 220 221 static const struct attribute_group ds1621_group = { 222 .attrs = ds1621_attributes, 223 }; 224 225 226 /* Return 0 if detection is successful, -ENODEV otherwise */ 227 static int ds1621_detect(struct i2c_client *client, int kind, 228 struct i2c_board_info *info) 229 { 230 struct i2c_adapter *adapter = client->adapter; 231 int conf, temp; 232 int i; 233 234 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 235 | I2C_FUNC_SMBUS_WORD_DATA 236 | I2C_FUNC_SMBUS_WRITE_BYTE)) 237 return -ENODEV; 238 239 /* Now, we do the remaining detection. It is lousy. */ 240 if (kind < 0) { 241 /* The NVB bit should be low if no EEPROM write has been 242 requested during the latest 10ms, which is highly 243 improbable in our case. */ 244 conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 245 if (conf < 0 || conf & DS1621_REG_CONFIG_NVB) 246 return -ENODEV; 247 /* The 7 lowest bits of a temperature should always be 0. */ 248 for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) { 249 temp = i2c_smbus_read_word_data(client, 250 DS1621_REG_TEMP[i]); 251 if (temp < 0 || (temp & 0x7f00)) 252 return -ENODEV; 253 } 254 } 255 256 strlcpy(info->type, "ds1621", I2C_NAME_SIZE); 257 258 return 0; 259 } 260 261 static int ds1621_probe(struct i2c_client *client, 262 const struct i2c_device_id *id) 263 { 264 struct ds1621_data *data; 265 int err; 266 267 data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL); 268 if (!data) { 269 err = -ENOMEM; 270 goto exit; 271 } 272 273 i2c_set_clientdata(client, data); 274 mutex_init(&data->update_lock); 275 276 /* Initialize the DS1621 chip */ 277 ds1621_init_client(client); 278 279 /* Register sysfs hooks */ 280 if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group))) 281 goto exit_free; 282 283 data->hwmon_dev = hwmon_device_register(&client->dev); 284 if (IS_ERR(data->hwmon_dev)) { 285 err = PTR_ERR(data->hwmon_dev); 286 goto exit_remove_files; 287 } 288 289 return 0; 290 291 exit_remove_files: 292 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 293 exit_free: 294 kfree(data); 295 exit: 296 return err; 297 } 298 299 static int ds1621_remove(struct i2c_client *client) 300 { 301 struct ds1621_data *data = i2c_get_clientdata(client); 302 303 hwmon_device_unregister(data->hwmon_dev); 304 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 305 306 kfree(data); 307 308 return 0; 309 } 310 311 static const struct i2c_device_id ds1621_id[] = { 312 { "ds1621", ds1621 }, 313 { "ds1625", ds1621 }, 314 { } 315 }; 316 MODULE_DEVICE_TABLE(i2c, ds1621_id); 317 318 /* This is the driver that will be inserted */ 319 static struct i2c_driver ds1621_driver = { 320 .class = I2C_CLASS_HWMON, 321 .driver = { 322 .name = "ds1621", 323 }, 324 .probe = ds1621_probe, 325 .remove = ds1621_remove, 326 .id_table = ds1621_id, 327 .detect = ds1621_detect, 328 .address_data = &addr_data, 329 }; 330 331 static int __init ds1621_init(void) 332 { 333 return i2c_add_driver(&ds1621_driver); 334 } 335 336 static void __exit ds1621_exit(void) 337 { 338 i2c_del_driver(&ds1621_driver); 339 } 340 341 342 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 343 MODULE_DESCRIPTION("DS1621 driver"); 344 MODULE_LICENSE("GPL"); 345 346 module_init(ds1621_init); 347 module_exit(ds1621_exit); 348