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 "lm75.h" 33 34 /* Addresses to scan */ 35 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 36 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; 37 38 /* Insmod parameters */ 39 I2C_CLIENT_INSMOD_1(ds1621); 40 static int polarity = -1; 41 module_param(polarity, int, 0); 42 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 43 44 /* Many DS1621 constants specified below */ 45 /* Config register used for detection */ 46 /* 7 6 5 4 3 2 1 0 */ 47 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ 48 #define DS1621_REG_CONFIG_NVB 0x10 49 #define DS1621_REG_CONFIG_POLARITY 0x02 50 #define DS1621_REG_CONFIG_1SHOT 0x01 51 #define DS1621_REG_CONFIG_DONE 0x80 52 53 /* The DS1621 registers */ 54 #define DS1621_REG_TEMP 0xAA /* word, RO */ 55 #define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */ 56 #define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */ 57 #define DS1621_REG_CONF 0xAC /* byte, RW */ 58 #define DS1621_COM_START 0xEE /* no data */ 59 #define DS1621_COM_STOP 0x22 /* no data */ 60 61 /* The DS1621 configuration register */ 62 #define DS1621_ALARM_TEMP_HIGH 0x40 63 #define DS1621_ALARM_TEMP_LOW 0x20 64 65 /* Conversions. Rounding and limit checking is only done on the TO_REG 66 variants. Note that you should be a bit careful with which arguments 67 these macros are called: arguments may be evaluated more than once. 68 Fixing this is just not worth it. */ 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 i2c_client client; 75 struct class_device *class_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, temp_min, temp_max; /* Register values, word */ 81 u8 conf; /* Register encoding, combined */ 82 }; 83 84 static int ds1621_attach_adapter(struct i2c_adapter *adapter); 85 static int ds1621_detect(struct i2c_adapter *adapter, int address, 86 int kind); 87 static void ds1621_init_client(struct i2c_client *client); 88 static int ds1621_detach_client(struct i2c_client *client); 89 static struct ds1621_data *ds1621_update_client(struct device *dev); 90 91 /* This is the driver that will be inserted */ 92 static struct i2c_driver ds1621_driver = { 93 .driver = { 94 .name = "ds1621", 95 }, 96 .id = I2C_DRIVERID_DS1621, 97 .attach_adapter = ds1621_attach_adapter, 98 .detach_client = ds1621_detach_client, 99 }; 100 101 /* All registers are word-sized, except for the configuration register. 102 DS1621 uses a high-byte first convention, which is exactly opposite to 103 the usual practice. */ 104 static int ds1621_read_value(struct i2c_client *client, u8 reg) 105 { 106 if (reg == DS1621_REG_CONF) 107 return i2c_smbus_read_byte_data(client, reg); 108 else 109 return swab16(i2c_smbus_read_word_data(client, reg)); 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 usual practice. */ 115 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) 116 { 117 if (reg == DS1621_REG_CONF) 118 return i2c_smbus_write_byte_data(client, reg, value); 119 else 120 return i2c_smbus_write_word_data(client, reg, swab16(value)); 121 } 122 123 static void ds1621_init_client(struct i2c_client *client) 124 { 125 int reg = ds1621_read_value(client, DS1621_REG_CONF); 126 /* switch to continuous conversion mode */ 127 reg &= ~ DS1621_REG_CONFIG_1SHOT; 128 129 /* setup output polarity */ 130 if (polarity == 0) 131 reg &= ~DS1621_REG_CONFIG_POLARITY; 132 else if (polarity == 1) 133 reg |= DS1621_REG_CONFIG_POLARITY; 134 135 ds1621_write_value(client, DS1621_REG_CONF, reg); 136 137 /* start conversion */ 138 i2c_smbus_write_byte(client, DS1621_COM_START); 139 } 140 141 #define show(value) \ 142 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ 143 { \ 144 struct ds1621_data *data = ds1621_update_client(dev); \ 145 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \ 146 } 147 148 show(temp); 149 show(temp_min); 150 show(temp_max); 151 152 #define set_temp(suffix, value, reg) \ 153 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \ 154 size_t count) \ 155 { \ 156 struct i2c_client *client = to_i2c_client(dev); \ 157 struct ds1621_data *data = ds1621_update_client(dev); \ 158 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \ 159 \ 160 mutex_lock(&data->update_lock); \ 161 data->value = val; \ 162 ds1621_write_value(client, reg, data->value); \ 163 mutex_unlock(&data->update_lock); \ 164 return count; \ 165 } 166 167 set_temp(min, temp_min, DS1621_REG_TEMP_MIN); 168 set_temp(max, temp_max, DS1621_REG_TEMP_MAX); 169 170 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) 171 { 172 struct ds1621_data *data = ds1621_update_client(dev); 173 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 174 } 175 176 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 177 static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL); 178 static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min); 179 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max); 180 181 182 static int ds1621_attach_adapter(struct i2c_adapter *adapter) 183 { 184 if (!(adapter->class & I2C_CLASS_HWMON)) 185 return 0; 186 return i2c_probe(adapter, &addr_data, ds1621_detect); 187 } 188 189 /* This function is called by i2c_probe */ 190 static int ds1621_detect(struct i2c_adapter *adapter, int address, 191 int kind) 192 { 193 int conf, temp; 194 struct i2c_client *new_client; 195 struct ds1621_data *data; 196 int err = 0; 197 198 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 199 | I2C_FUNC_SMBUS_WORD_DATA 200 | I2C_FUNC_SMBUS_WRITE_BYTE)) 201 goto exit; 202 203 /* OK. For now, we presume we have a valid client. We now create the 204 client structure, even though we cannot fill it completely yet. 205 But it allows us to access ds1621_{read,write}_value. */ 206 if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) { 207 err = -ENOMEM; 208 goto exit; 209 } 210 211 new_client = &data->client; 212 i2c_set_clientdata(new_client, data); 213 new_client->addr = address; 214 new_client->adapter = adapter; 215 new_client->driver = &ds1621_driver; 216 new_client->flags = 0; 217 218 219 /* Now, we do the remaining detection. It is lousy. */ 220 if (kind < 0) { 221 /* The NVB bit should be low if no EEPROM write has been 222 requested during the latest 10ms, which is highly 223 improbable in our case. */ 224 conf = ds1621_read_value(new_client, DS1621_REG_CONF); 225 if (conf & DS1621_REG_CONFIG_NVB) 226 goto exit_free; 227 /* The 7 lowest bits of a temperature should always be 0. */ 228 temp = ds1621_read_value(new_client, DS1621_REG_TEMP); 229 if (temp & 0x007f) 230 goto exit_free; 231 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN); 232 if (temp & 0x007f) 233 goto exit_free; 234 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX); 235 if (temp & 0x007f) 236 goto exit_free; 237 } 238 239 /* Determine the chip type - only one kind supported! */ 240 if (kind <= 0) 241 kind = ds1621; 242 243 /* Fill in remaining client fields and put it into the global list */ 244 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE); 245 data->valid = 0; 246 mutex_init(&data->update_lock); 247 248 /* Tell the I2C layer a new client has arrived */ 249 if ((err = i2c_attach_client(new_client))) 250 goto exit_free; 251 252 /* Initialize the DS1621 chip */ 253 ds1621_init_client(new_client); 254 255 /* Register sysfs hooks */ 256 data->class_dev = hwmon_device_register(&new_client->dev); 257 if (IS_ERR(data->class_dev)) { 258 err = PTR_ERR(data->class_dev); 259 goto exit_detach; 260 } 261 262 device_create_file(&new_client->dev, &dev_attr_alarms); 263 device_create_file(&new_client->dev, &dev_attr_temp1_input); 264 device_create_file(&new_client->dev, &dev_attr_temp1_min); 265 device_create_file(&new_client->dev, &dev_attr_temp1_max); 266 267 return 0; 268 269 /* OK, this is not exactly good programming practice, usually. But it is 270 very code-efficient in this case. */ 271 exit_detach: 272 i2c_detach_client(new_client); 273 exit_free: 274 kfree(data); 275 exit: 276 return err; 277 } 278 279 static int ds1621_detach_client(struct i2c_client *client) 280 { 281 struct ds1621_data *data = i2c_get_clientdata(client); 282 int err; 283 284 hwmon_device_unregister(data->class_dev); 285 286 if ((err = i2c_detach_client(client))) 287 return err; 288 289 kfree(data); 290 291 return 0; 292 } 293 294 295 static struct ds1621_data *ds1621_update_client(struct device *dev) 296 { 297 struct i2c_client *client = to_i2c_client(dev); 298 struct ds1621_data *data = i2c_get_clientdata(client); 299 u8 new_conf; 300 301 mutex_lock(&data->update_lock); 302 303 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 304 || !data->valid) { 305 306 dev_dbg(&client->dev, "Starting ds1621 update\n"); 307 308 data->conf = ds1621_read_value(client, DS1621_REG_CONF); 309 310 data->temp = ds1621_read_value(client, DS1621_REG_TEMP); 311 312 data->temp_min = ds1621_read_value(client, 313 DS1621_REG_TEMP_MIN); 314 data->temp_max = ds1621_read_value(client, 315 DS1621_REG_TEMP_MAX); 316 317 /* reset alarms if necessary */ 318 new_conf = data->conf; 319 if (data->temp < data->temp_min) 320 new_conf &= ~DS1621_ALARM_TEMP_LOW; 321 if (data->temp > data->temp_max) 322 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 323 if (data->conf != new_conf) 324 ds1621_write_value(client, DS1621_REG_CONF, 325 new_conf); 326 327 data->last_updated = jiffies; 328 data->valid = 1; 329 } 330 331 mutex_unlock(&data->update_lock); 332 333 return data; 334 } 335 336 static int __init ds1621_init(void) 337 { 338 return i2c_add_driver(&ds1621_driver); 339 } 340 341 static void __exit ds1621_exit(void) 342 { 343 i2c_del_driver(&ds1621_driver); 344 } 345 346 347 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 348 MODULE_DESCRIPTION("DS1621 driver"); 349 MODULE_LICENSE("GPL"); 350 351 module_init(ds1621_init); 352 module_exit(ds1621_exit); 353