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/err.h> 31 #include <linux/mutex.h> 32 #include <linux/sysfs.h> 33 #include "lm75.h" 34 35 /* Addresses to scan */ 36 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 37 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; 38 39 /* Insmod parameters */ 40 I2C_CLIENT_INSMOD_1(ds1621); 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 #define DS1621_REG_TEMP 0xAA /* word, RO */ 56 #define DS1621_REG_TEMP_MIN 0xA2 /* word, RW */ 57 #define DS1621_REG_TEMP_MAX 0xA1 /* word, RW */ 58 #define DS1621_REG_CONF 0xAC /* byte, RW */ 59 #define DS1621_COM_START 0xEE /* no data */ 60 #define DS1621_COM_STOP 0x22 /* no data */ 61 62 /* The DS1621 configuration register */ 63 #define DS1621_ALARM_TEMP_HIGH 0x40 64 #define DS1621_ALARM_TEMP_LOW 0x20 65 66 /* Conversions. Rounding and limit checking is only done on the TO_REG 67 variants. Note that you should be a bit careful with which arguments 68 these macros are called: arguments may be evaluated more than once. 69 Fixing this is just not worth it. */ 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 i2c_client client; 76 struct class_device *class_dev; 77 struct mutex update_lock; 78 char valid; /* !=0 if following fields are valid */ 79 unsigned long last_updated; /* In jiffies */ 80 81 u16 temp, temp_min, temp_max; /* Register values, word */ 82 u8 conf; /* Register encoding, combined */ 83 }; 84 85 static int ds1621_attach_adapter(struct i2c_adapter *adapter); 86 static int ds1621_detect(struct i2c_adapter *adapter, int address, 87 int kind); 88 static void ds1621_init_client(struct i2c_client *client); 89 static int ds1621_detach_client(struct i2c_client *client); 90 static struct ds1621_data *ds1621_update_client(struct device *dev); 91 92 /* This is the driver that will be inserted */ 93 static struct i2c_driver ds1621_driver = { 94 .driver = { 95 .name = "ds1621", 96 }, 97 .id = I2C_DRIVERID_DS1621, 98 .attach_adapter = ds1621_attach_adapter, 99 .detach_client = ds1621_detach_client, 100 }; 101 102 /* All registers are word-sized, except for the configuration register. 103 DS1621 uses a high-byte first convention, which is exactly opposite to 104 the usual practice. */ 105 static int ds1621_read_value(struct i2c_client *client, u8 reg) 106 { 107 if (reg == DS1621_REG_CONF) 108 return i2c_smbus_read_byte_data(client, reg); 109 else 110 return swab16(i2c_smbus_read_word_data(client, reg)); 111 } 112 113 /* All registers are word-sized, except for the configuration register. 114 DS1621 uses a high-byte first convention, which is exactly opposite to 115 the usual practice. */ 116 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) 117 { 118 if (reg == DS1621_REG_CONF) 119 return i2c_smbus_write_byte_data(client, reg, value); 120 else 121 return i2c_smbus_write_word_data(client, reg, swab16(value)); 122 } 123 124 static void ds1621_init_client(struct i2c_client *client) 125 { 126 int reg = ds1621_read_value(client, DS1621_REG_CONF); 127 /* switch to continuous conversion mode */ 128 reg &= ~ DS1621_REG_CONFIG_1SHOT; 129 130 /* setup output polarity */ 131 if (polarity == 0) 132 reg &= ~DS1621_REG_CONFIG_POLARITY; 133 else if (polarity == 1) 134 reg |= DS1621_REG_CONFIG_POLARITY; 135 136 ds1621_write_value(client, DS1621_REG_CONF, reg); 137 138 /* start conversion */ 139 i2c_smbus_write_byte(client, DS1621_COM_START); 140 } 141 142 #define show(value) \ 143 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ 144 { \ 145 struct ds1621_data *data = ds1621_update_client(dev); \ 146 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \ 147 } 148 149 show(temp); 150 show(temp_min); 151 show(temp_max); 152 153 #define set_temp(suffix, value, reg) \ 154 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \ 155 size_t count) \ 156 { \ 157 struct i2c_client *client = to_i2c_client(dev); \ 158 struct ds1621_data *data = ds1621_update_client(dev); \ 159 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \ 160 \ 161 mutex_lock(&data->update_lock); \ 162 data->value = val; \ 163 ds1621_write_value(client, reg, data->value); \ 164 mutex_unlock(&data->update_lock); \ 165 return count; \ 166 } 167 168 set_temp(min, temp_min, DS1621_REG_TEMP_MIN); 169 set_temp(max, temp_max, DS1621_REG_TEMP_MAX); 170 171 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) 172 { 173 struct ds1621_data *data = ds1621_update_client(dev); 174 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 175 } 176 177 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 178 static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL); 179 static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min); 180 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max); 181 182 static struct attribute *ds1621_attributes[] = { 183 &dev_attr_temp1_input.attr, 184 &dev_attr_temp1_min.attr, 185 &dev_attr_temp1_max.attr, 186 &dev_attr_alarms.attr, 187 NULL 188 }; 189 190 static const struct attribute_group ds1621_group = { 191 .attrs = ds1621_attributes, 192 }; 193 194 195 static int ds1621_attach_adapter(struct i2c_adapter *adapter) 196 { 197 if (!(adapter->class & I2C_CLASS_HWMON)) 198 return 0; 199 return i2c_probe(adapter, &addr_data, ds1621_detect); 200 } 201 202 /* This function is called by i2c_probe */ 203 static int ds1621_detect(struct i2c_adapter *adapter, int address, 204 int kind) 205 { 206 int conf, temp; 207 struct i2c_client *new_client; 208 struct ds1621_data *data; 209 int err = 0; 210 211 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 212 | I2C_FUNC_SMBUS_WORD_DATA 213 | I2C_FUNC_SMBUS_WRITE_BYTE)) 214 goto exit; 215 216 /* OK. For now, we presume we have a valid client. We now create the 217 client structure, even though we cannot fill it completely yet. 218 But it allows us to access ds1621_{read,write}_value. */ 219 if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) { 220 err = -ENOMEM; 221 goto exit; 222 } 223 224 new_client = &data->client; 225 i2c_set_clientdata(new_client, data); 226 new_client->addr = address; 227 new_client->adapter = adapter; 228 new_client->driver = &ds1621_driver; 229 new_client->flags = 0; 230 231 232 /* Now, we do the remaining detection. It is lousy. */ 233 if (kind < 0) { 234 /* The NVB bit should be low if no EEPROM write has been 235 requested during the latest 10ms, which is highly 236 improbable in our case. */ 237 conf = ds1621_read_value(new_client, DS1621_REG_CONF); 238 if (conf & DS1621_REG_CONFIG_NVB) 239 goto exit_free; 240 /* The 7 lowest bits of a temperature should always be 0. */ 241 temp = ds1621_read_value(new_client, DS1621_REG_TEMP); 242 if (temp & 0x007f) 243 goto exit_free; 244 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN); 245 if (temp & 0x007f) 246 goto exit_free; 247 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX); 248 if (temp & 0x007f) 249 goto exit_free; 250 } 251 252 /* Determine the chip type - only one kind supported! */ 253 if (kind <= 0) 254 kind = ds1621; 255 256 /* Fill in remaining client fields and put it into the global list */ 257 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE); 258 data->valid = 0; 259 mutex_init(&data->update_lock); 260 261 /* Tell the I2C layer a new client has arrived */ 262 if ((err = i2c_attach_client(new_client))) 263 goto exit_free; 264 265 /* Initialize the DS1621 chip */ 266 ds1621_init_client(new_client); 267 268 /* Register sysfs hooks */ 269 if ((err = sysfs_create_group(&new_client->dev.kobj, &ds1621_group))) 270 goto exit_detach; 271 272 data->class_dev = hwmon_device_register(&new_client->dev); 273 if (IS_ERR(data->class_dev)) { 274 err = PTR_ERR(data->class_dev); 275 goto exit_remove_files; 276 } 277 278 return 0; 279 280 exit_remove_files: 281 sysfs_remove_group(&new_client->dev.kobj, &ds1621_group); 282 exit_detach: 283 i2c_detach_client(new_client); 284 exit_free: 285 kfree(data); 286 exit: 287 return err; 288 } 289 290 static int ds1621_detach_client(struct i2c_client *client) 291 { 292 struct ds1621_data *data = i2c_get_clientdata(client); 293 int err; 294 295 hwmon_device_unregister(data->class_dev); 296 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 297 298 if ((err = i2c_detach_client(client))) 299 return err; 300 301 kfree(data); 302 303 return 0; 304 } 305 306 307 static struct ds1621_data *ds1621_update_client(struct device *dev) 308 { 309 struct i2c_client *client = to_i2c_client(dev); 310 struct ds1621_data *data = i2c_get_clientdata(client); 311 u8 new_conf; 312 313 mutex_lock(&data->update_lock); 314 315 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 316 || !data->valid) { 317 318 dev_dbg(&client->dev, "Starting ds1621 update\n"); 319 320 data->conf = ds1621_read_value(client, DS1621_REG_CONF); 321 322 data->temp = ds1621_read_value(client, DS1621_REG_TEMP); 323 324 data->temp_min = ds1621_read_value(client, 325 DS1621_REG_TEMP_MIN); 326 data->temp_max = ds1621_read_value(client, 327 DS1621_REG_TEMP_MAX); 328 329 /* reset alarms if necessary */ 330 new_conf = data->conf; 331 if (data->temp > data->temp_min) 332 new_conf &= ~DS1621_ALARM_TEMP_LOW; 333 if (data->temp < data->temp_max) 334 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 335 if (data->conf != new_conf) 336 ds1621_write_value(client, DS1621_REG_CONF, 337 new_conf); 338 339 data->last_updated = jiffies; 340 data->valid = 1; 341 } 342 343 mutex_unlock(&data->update_lock); 344 345 return data; 346 } 347 348 static int __init ds1621_init(void) 349 { 350 return i2c_add_driver(&ds1621_driver); 351 } 352 353 static void __exit ds1621_exit(void) 354 { 355 i2c_del_driver(&ds1621_driver); 356 } 357 358 359 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 360 MODULE_DESCRIPTION("DS1621 driver"); 361 MODULE_LICENSE("GPL"); 362 363 module_init(ds1621_init); 364 module_exit(ds1621_exit); 365