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 <jdelvare@suse.de> 8 * 9 * The DS1621 device is a digital temperature/thermometer with 9-bit 10 * resolution, a thermal alarm output (Tout), and user-defined minimum 11 * and maximum temperature thresholds (TH and TL). 12 * 13 * The DS1625, DS1631, DS1721, and DS1731 are pin compatible with the DS1621 14 * and similar in operation, with slight variations as noted in the device 15 * datasheets (please refer to www.maximintegrated.com for specific 16 * device information). 17 * 18 * Since the DS1621 was the first chipset supported by this driver, 19 * most comments will refer to this chipset, but are actually general 20 * and concern all supported chipsets, unless mentioned otherwise. 21 * 22 * This program is free software; you can redistribute it and/or modify 23 * it under the terms of the GNU General Public License as published by 24 * the Free Software Foundation; either version 2 of the License, or 25 * (at your option) any later version. 26 * 27 * This program is distributed in the hope that it will be useful, 28 * but WITHOUT ANY WARRANTY; without even the implied warranty of 29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 30 * GNU General Public License for more details. 31 * 32 * You should have received a copy of the GNU General Public License 33 * along with this program; if not, write to the Free Software 34 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 35 */ 36 37 #include <linux/module.h> 38 #include <linux/init.h> 39 #include <linux/slab.h> 40 #include <linux/jiffies.h> 41 #include <linux/i2c.h> 42 #include <linux/hwmon.h> 43 #include <linux/hwmon-sysfs.h> 44 #include <linux/err.h> 45 #include <linux/mutex.h> 46 #include <linux/sysfs.h> 47 #include <linux/kernel.h> 48 49 /* Supported devices */ 50 enum chips { ds1621, ds1625, ds1631, ds1721, ds1731 }; 51 52 /* Insmod parameters */ 53 static int polarity = -1; 54 module_param(polarity, int, 0); 55 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 56 57 /* 58 * The Configuration/Status register 59 * 60 * - DS1621: 61 * 7 6 5 4 3 2 1 0 62 * |Done|THF |TLF |NVB | X | X |POL |1SHOT| 63 * 64 * - DS1625: 65 * 7 6 5 4 3 2 1 0 66 * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT| 67 * 68 * - DS1631, DS1731: 69 * 7 6 5 4 3 2 1 0 70 * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT| 71 * 72 * - DS1721: 73 * 7 6 5 4 3 2 1 0 74 * |Done| X | X | U | R1 | R0 |POL |1SHOT| 75 * 76 * Where: 77 * - 'X' is Reserved 78 * - 'U' is Undefined 79 */ 80 #define DS1621_REG_CONFIG_NVB 0x10 81 #define DS1621_REG_CONFIG_RESOL 0x0C 82 #define DS1621_REG_CONFIG_POLARITY 0x02 83 #define DS1621_REG_CONFIG_1SHOT 0x01 84 #define DS1621_REG_CONFIG_DONE 0x80 85 86 #define DS1621_REG_CONFIG_RESOL_SHIFT 2 87 88 /* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */ 89 static const unsigned short ds1721_convrates[] = { 90 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */ 91 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */ 92 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */ 93 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */ 94 }; 95 96 #define DS1621_CONVERSION_MAX 750 97 #define DS1625_CONVERSION_MAX 500 98 99 #define DS1621_TEMP_MAX 125000 100 #define DS1621_TEMP_MIN (-55000) 101 102 /* The DS1621 temperature registers */ 103 static const u8 DS1621_REG_TEMP[3] = { 104 0xAA, /* input, word, RO */ 105 0xA2, /* min, word, RW */ 106 0xA1, /* max, word, RW */ 107 }; 108 #define DS1621_REG_CONF 0xAC /* byte, RW */ 109 #define DS1621_COM_START 0xEE /* no data */ 110 #define DS1721_COM_START 0x51 /* no data */ 111 #define DS1621_COM_STOP 0x22 /* no data */ 112 113 /* The DS1621 configuration register */ 114 #define DS1621_ALARM_TEMP_HIGH 0x40 115 #define DS1621_ALARM_TEMP_LOW 0x20 116 117 /* Conversions */ 118 #define ALARMS_FROM_REG(val) ((val) & \ 119 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) 120 121 /* Each client has this additional data */ 122 struct ds1621_data { 123 struct i2c_client *client; 124 struct mutex update_lock; 125 char valid; /* !=0 if following fields are valid */ 126 unsigned long last_updated; /* In jiffies */ 127 enum chips kind; /* device type */ 128 129 u16 temp[3]; /* Register values, word */ 130 u8 conf; /* Register encoding, combined */ 131 u8 zbits; /* Resolution encoded as number of 132 * zero bits */ 133 u16 update_interval; /* Conversion rate in milliseconds */ 134 }; 135 136 static inline int DS1621_TEMP_FROM_REG(u16 reg) 137 { 138 return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10); 139 } 140 141 /* 142 * TEMP: 0.001C/bit (-55C to +125C) 143 * REG: 144 * - 1621, 1625: 0.5C/bit, 7 zero-bits 145 * - 1631, 1721, 1731: 0.0625C/bit, 4 zero-bits 146 */ 147 static inline u16 DS1621_TEMP_TO_REG(long temp, u8 zbits) 148 { 149 temp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX); 150 temp = DIV_ROUND_CLOSEST(temp * (1 << (8 - zbits)), 1000) << zbits; 151 return temp; 152 } 153 154 static void ds1621_init_client(struct ds1621_data *data, 155 struct i2c_client *client) 156 { 157 u8 conf, new_conf, sreg, resol; 158 159 new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 160 /* switch to continuous conversion mode */ 161 new_conf &= ~DS1621_REG_CONFIG_1SHOT; 162 163 /* setup output polarity */ 164 if (polarity == 0) 165 new_conf &= ~DS1621_REG_CONFIG_POLARITY; 166 else if (polarity == 1) 167 new_conf |= DS1621_REG_CONFIG_POLARITY; 168 169 if (conf != new_conf) 170 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); 171 172 switch (data->kind) { 173 case ds1625: 174 data->update_interval = DS1625_CONVERSION_MAX; 175 data->zbits = 7; 176 sreg = DS1621_COM_START; 177 break; 178 case ds1631: 179 case ds1721: 180 case ds1731: 181 resol = (new_conf & DS1621_REG_CONFIG_RESOL) >> 182 DS1621_REG_CONFIG_RESOL_SHIFT; 183 data->update_interval = ds1721_convrates[resol]; 184 data->zbits = 7 - resol; 185 sreg = DS1721_COM_START; 186 break; 187 default: 188 data->update_interval = DS1621_CONVERSION_MAX; 189 data->zbits = 7; 190 sreg = DS1621_COM_START; 191 break; 192 } 193 194 /* start conversion */ 195 i2c_smbus_write_byte(client, sreg); 196 } 197 198 static struct ds1621_data *ds1621_update_client(struct device *dev) 199 { 200 struct ds1621_data *data = dev_get_drvdata(dev); 201 struct i2c_client *client = data->client; 202 u8 new_conf; 203 204 mutex_lock(&data->update_lock); 205 206 if (time_after(jiffies, data->last_updated + data->update_interval) || 207 !data->valid) { 208 int i; 209 210 dev_dbg(&client->dev, "Starting ds1621 update\n"); 211 212 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 213 214 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 215 data->temp[i] = i2c_smbus_read_word_swapped(client, 216 DS1621_REG_TEMP[i]); 217 218 /* reset alarms if necessary */ 219 new_conf = data->conf; 220 if (data->temp[0] > data->temp[1]) /* input > min */ 221 new_conf &= ~DS1621_ALARM_TEMP_LOW; 222 if (data->temp[0] < data->temp[2]) /* input < max */ 223 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 224 if (data->conf != new_conf) 225 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, 226 new_conf); 227 228 data->last_updated = jiffies; 229 data->valid = 1; 230 } 231 232 mutex_unlock(&data->update_lock); 233 234 return data; 235 } 236 237 static ssize_t temp_show(struct device *dev, struct device_attribute *da, 238 char *buf) 239 { 240 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 241 struct ds1621_data *data = ds1621_update_client(dev); 242 return sprintf(buf, "%d\n", 243 DS1621_TEMP_FROM_REG(data->temp[attr->index])); 244 } 245 246 static ssize_t temp_store(struct device *dev, struct device_attribute *da, 247 const char *buf, size_t count) 248 { 249 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 250 struct ds1621_data *data = dev_get_drvdata(dev); 251 long val; 252 int err; 253 254 err = kstrtol(buf, 10, &val); 255 if (err) 256 return err; 257 258 mutex_lock(&data->update_lock); 259 data->temp[attr->index] = DS1621_TEMP_TO_REG(val, data->zbits); 260 i2c_smbus_write_word_swapped(data->client, DS1621_REG_TEMP[attr->index], 261 data->temp[attr->index]); 262 mutex_unlock(&data->update_lock); 263 return count; 264 } 265 266 static ssize_t alarms_show(struct device *dev, struct device_attribute *da, 267 char *buf) 268 { 269 struct ds1621_data *data = ds1621_update_client(dev); 270 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 271 } 272 273 static ssize_t alarm_show(struct device *dev, struct device_attribute *da, 274 char *buf) 275 { 276 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 277 struct ds1621_data *data = ds1621_update_client(dev); 278 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 279 } 280 281 static ssize_t update_interval_show(struct device *dev, 282 struct device_attribute *da, char *buf) 283 { 284 struct ds1621_data *data = dev_get_drvdata(dev); 285 return scnprintf(buf, PAGE_SIZE, "%hu\n", data->update_interval); 286 } 287 288 static ssize_t update_interval_store(struct device *dev, 289 struct device_attribute *da, 290 const char *buf, size_t count) 291 { 292 struct ds1621_data *data = dev_get_drvdata(dev); 293 struct i2c_client *client = data->client; 294 unsigned long convrate; 295 s32 err; 296 int resol = 0; 297 298 err = kstrtoul(buf, 10, &convrate); 299 if (err) 300 return err; 301 302 /* Convert rate into resolution bits */ 303 while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) && 304 convrate > ds1721_convrates[resol]) 305 resol++; 306 307 mutex_lock(&data->update_lock); 308 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 309 data->conf &= ~DS1621_REG_CONFIG_RESOL; 310 data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT); 311 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf); 312 data->update_interval = ds1721_convrates[resol]; 313 data->zbits = 7 - resol; 314 mutex_unlock(&data->update_lock); 315 316 return count; 317 } 318 319 static DEVICE_ATTR_RO(alarms); 320 static DEVICE_ATTR_RW(update_interval); 321 322 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0); 323 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1); 324 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2); 325 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS1621_ALARM_TEMP_LOW); 326 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS1621_ALARM_TEMP_HIGH); 327 328 static struct attribute *ds1621_attributes[] = { 329 &sensor_dev_attr_temp1_input.dev_attr.attr, 330 &sensor_dev_attr_temp1_min.dev_attr.attr, 331 &sensor_dev_attr_temp1_max.dev_attr.attr, 332 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 333 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 334 &dev_attr_alarms.attr, 335 &dev_attr_update_interval.attr, 336 NULL 337 }; 338 339 static umode_t ds1621_attribute_visible(struct kobject *kobj, 340 struct attribute *attr, int index) 341 { 342 struct device *dev = container_of(kobj, struct device, kobj); 343 struct ds1621_data *data = dev_get_drvdata(dev); 344 345 if (attr == &dev_attr_update_interval.attr) 346 if (data->kind == ds1621 || data->kind == ds1625) 347 /* shhh, we're hiding update_interval */ 348 return 0; 349 return attr->mode; 350 } 351 352 static const struct attribute_group ds1621_group = { 353 .attrs = ds1621_attributes, 354 .is_visible = ds1621_attribute_visible 355 }; 356 __ATTRIBUTE_GROUPS(ds1621); 357 358 static int ds1621_probe(struct i2c_client *client, 359 const struct i2c_device_id *id) 360 { 361 struct ds1621_data *data; 362 struct device *hwmon_dev; 363 364 data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data), 365 GFP_KERNEL); 366 if (!data) 367 return -ENOMEM; 368 369 mutex_init(&data->update_lock); 370 371 data->kind = id->driver_data; 372 data->client = client; 373 374 /* Initialize the DS1621 chip */ 375 ds1621_init_client(data, client); 376 377 hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev, 378 client->name, data, 379 ds1621_groups); 380 return PTR_ERR_OR_ZERO(hwmon_dev); 381 } 382 383 static const struct i2c_device_id ds1621_id[] = { 384 { "ds1621", ds1621 }, 385 { "ds1625", ds1625 }, 386 { "ds1631", ds1631 }, 387 { "ds1721", ds1721 }, 388 { "ds1731", ds1731 }, 389 { } 390 }; 391 MODULE_DEVICE_TABLE(i2c, ds1621_id); 392 393 /* This is the driver that will be inserted */ 394 static struct i2c_driver ds1621_driver = { 395 .class = I2C_CLASS_HWMON, 396 .driver = { 397 .name = "ds1621", 398 }, 399 .probe = ds1621_probe, 400 .id_table = ds1621_id, 401 }; 402 403 module_i2c_driver(ds1621_driver); 404 405 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 406 MODULE_DESCRIPTION("DS1621 driver"); 407 MODULE_LICENSE("GPL"); 408