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 "lm75.h" 32 33 /* Addresses to scan */ 34 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 35 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; 36 37 /* Insmod parameters */ 38 I2C_CLIENT_INSMOD_1(ds1621); 39 static int polarity = -1; 40 module_param(polarity, int, 0); 41 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 42 43 /* Many DS1621 constants specified below */ 44 /* Config register used for detection */ 45 /* 7 6 5 4 3 2 1 0 */ 46 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ 47 #define DS1621_REG_CONFIG_NVB 0x10 48 #define DS1621_REG_CONFIG_POLARITY 0x02 49 #define DS1621_REG_CONFIG_1SHOT 0x01 50 #define DS1621_REG_CONFIG_DONE 0x80 51 52 /* The DS1621 registers */ 53 #define DS1621_REG_TEMP 0xAA /* word, RO */ 54 #define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */ 55 #define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */ 56 #define DS1621_REG_CONF 0xAC /* byte, RW */ 57 #define DS1621_COM_START 0xEE /* no data */ 58 #define DS1621_COM_STOP 0x22 /* no data */ 59 60 /* The DS1621 configuration register */ 61 #define DS1621_ALARM_TEMP_HIGH 0x40 62 #define DS1621_ALARM_TEMP_LOW 0x20 63 64 /* Conversions. Rounding and limit checking is only done on the TO_REG 65 variants. Note that you should be a bit careful with which arguments 66 these macros are called: arguments may be evaluated more than once. 67 Fixing this is just not worth it. */ 68 #define ALARMS_FROM_REG(val) ((val) & \ 69 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) 70 71 /* Each client has this additional data */ 72 struct ds1621_data { 73 struct i2c_client client; 74 struct class_device *class_dev; 75 struct semaphore update_lock; 76 char valid; /* !=0 if following fields are valid */ 77 unsigned long last_updated; /* In jiffies */ 78 79 u16 temp, temp_min, temp_max; /* Register values, word */ 80 u8 conf; /* Register encoding, combined */ 81 }; 82 83 static int ds1621_attach_adapter(struct i2c_adapter *adapter); 84 static int ds1621_detect(struct i2c_adapter *adapter, int address, 85 int kind); 86 static void ds1621_init_client(struct i2c_client *client); 87 static int ds1621_detach_client(struct i2c_client *client); 88 static struct ds1621_data *ds1621_update_client(struct device *dev); 89 90 /* This is the driver that will be inserted */ 91 static struct i2c_driver ds1621_driver = { 92 .owner = THIS_MODULE, 93 .name = "ds1621", 94 .id = I2C_DRIVERID_DS1621, 95 .flags = I2C_DF_NOTIFY, 96 .attach_adapter = ds1621_attach_adapter, 97 .detach_client = ds1621_detach_client, 98 }; 99 100 /* All registers are word-sized, except for the configuration register. 101 DS1621 uses a high-byte first convention, which is exactly opposite to 102 the usual practice. */ 103 static int ds1621_read_value(struct i2c_client *client, u8 reg) 104 { 105 if (reg == DS1621_REG_CONF) 106 return i2c_smbus_read_byte_data(client, reg); 107 else 108 return swab16(i2c_smbus_read_word_data(client, reg)); 109 } 110 111 /* All registers are word-sized, except for the configuration register. 112 DS1621 uses a high-byte first convention, which is exactly opposite to 113 the usual practice. */ 114 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) 115 { 116 if (reg == DS1621_REG_CONF) 117 return i2c_smbus_write_byte_data(client, reg, value); 118 else 119 return i2c_smbus_write_word_data(client, reg, swab16(value)); 120 } 121 122 static void ds1621_init_client(struct i2c_client *client) 123 { 124 int reg = ds1621_read_value(client, DS1621_REG_CONF); 125 /* switch to continuous conversion mode */ 126 reg &= ~ DS1621_REG_CONFIG_1SHOT; 127 128 /* setup output polarity */ 129 if (polarity == 0) 130 reg &= ~DS1621_REG_CONFIG_POLARITY; 131 else if (polarity == 1) 132 reg |= DS1621_REG_CONFIG_POLARITY; 133 134 ds1621_write_value(client, DS1621_REG_CONF, reg); 135 136 /* start conversion */ 137 i2c_smbus_write_byte(client, DS1621_COM_START); 138 } 139 140 #define show(value) \ 141 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ 142 { \ 143 struct ds1621_data *data = ds1621_update_client(dev); \ 144 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \ 145 } 146 147 show(temp); 148 show(temp_min); 149 show(temp_max); 150 151 #define set_temp(suffix, value, reg) \ 152 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \ 153 size_t count) \ 154 { \ 155 struct i2c_client *client = to_i2c_client(dev); \ 156 struct ds1621_data *data = ds1621_update_client(dev); \ 157 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \ 158 \ 159 down(&data->update_lock); \ 160 data->value = val; \ 161 ds1621_write_value(client, reg, data->value); \ 162 up(&data->update_lock); \ 163 return count; \ 164 } 165 166 set_temp(min, temp_min, DS1621_REG_TEMP_MIN); 167 set_temp(max, temp_max, DS1621_REG_TEMP_MAX); 168 169 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) 170 { 171 struct ds1621_data *data = ds1621_update_client(dev); 172 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 173 } 174 175 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 176 static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL); 177 static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min); 178 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max); 179 180 181 static int ds1621_attach_adapter(struct i2c_adapter *adapter) 182 { 183 return i2c_probe(adapter, &addr_data, ds1621_detect); 184 } 185 186 /* This function is called by i2c_probe */ 187 int ds1621_detect(struct i2c_adapter *adapter, int address, 188 int kind) 189 { 190 int conf, temp; 191 struct i2c_client *new_client; 192 struct ds1621_data *data; 193 int err = 0; 194 195 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 196 | I2C_FUNC_SMBUS_WORD_DATA 197 | I2C_FUNC_SMBUS_WRITE_BYTE)) 198 goto exit; 199 200 /* OK. For now, we presume we have a valid client. We now create the 201 client structure, even though we cannot fill it completely yet. 202 But it allows us to access ds1621_{read,write}_value. */ 203 if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) { 204 err = -ENOMEM; 205 goto exit; 206 } 207 memset(data, 0, sizeof(struct ds1621_data)); 208 209 new_client = &data->client; 210 i2c_set_clientdata(new_client, data); 211 new_client->addr = address; 212 new_client->adapter = adapter; 213 new_client->driver = &ds1621_driver; 214 new_client->flags = 0; 215 216 217 /* Now, we do the remaining detection. It is lousy. */ 218 if (kind < 0) { 219 /* The NVB bit should be low if no EEPROM write has been 220 requested during the latest 10ms, which is highly 221 improbable in our case. */ 222 conf = ds1621_read_value(new_client, DS1621_REG_CONF); 223 if (conf & DS1621_REG_CONFIG_NVB) 224 goto exit_free; 225 /* The 7 lowest bits of a temperature should always be 0. */ 226 temp = ds1621_read_value(new_client, DS1621_REG_TEMP); 227 if (temp & 0x007f) 228 goto exit_free; 229 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN); 230 if (temp & 0x007f) 231 goto exit_free; 232 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX); 233 if (temp & 0x007f) 234 goto exit_free; 235 } 236 237 /* Determine the chip type - only one kind supported! */ 238 if (kind <= 0) 239 kind = ds1621; 240 241 /* Fill in remaining client fields and put it into the global list */ 242 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE); 243 data->valid = 0; 244 init_MUTEX(&data->update_lock); 245 246 /* Tell the I2C layer a new client has arrived */ 247 if ((err = i2c_attach_client(new_client))) 248 goto exit_free; 249 250 /* Initialize the DS1621 chip */ 251 ds1621_init_client(new_client); 252 253 /* Register sysfs hooks */ 254 data->class_dev = hwmon_device_register(&new_client->dev); 255 if (IS_ERR(data->class_dev)) { 256 err = PTR_ERR(data->class_dev); 257 goto exit_detach; 258 } 259 260 device_create_file(&new_client->dev, &dev_attr_alarms); 261 device_create_file(&new_client->dev, &dev_attr_temp1_input); 262 device_create_file(&new_client->dev, &dev_attr_temp1_min); 263 device_create_file(&new_client->dev, &dev_attr_temp1_max); 264 265 return 0; 266 267 /* OK, this is not exactly good programming practice, usually. But it is 268 very code-efficient in this case. */ 269 exit_detach: 270 i2c_detach_client(new_client); 271 exit_free: 272 kfree(data); 273 exit: 274 return err; 275 } 276 277 static int ds1621_detach_client(struct i2c_client *client) 278 { 279 struct ds1621_data *data = i2c_get_clientdata(client); 280 int err; 281 282 hwmon_device_unregister(data->class_dev); 283 284 if ((err = i2c_detach_client(client))) 285 return err; 286 287 kfree(data); 288 289 return 0; 290 } 291 292 293 static struct ds1621_data *ds1621_update_client(struct device *dev) 294 { 295 struct i2c_client *client = to_i2c_client(dev); 296 struct ds1621_data *data = i2c_get_clientdata(client); 297 u8 new_conf; 298 299 down(&data->update_lock); 300 301 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 302 || !data->valid) { 303 304 dev_dbg(&client->dev, "Starting ds1621 update\n"); 305 306 data->conf = ds1621_read_value(client, DS1621_REG_CONF); 307 308 data->temp = ds1621_read_value(client, DS1621_REG_TEMP); 309 310 data->temp_min = ds1621_read_value(client, 311 DS1621_REG_TEMP_MIN); 312 data->temp_max = ds1621_read_value(client, 313 DS1621_REG_TEMP_MAX); 314 315 /* reset alarms if necessary */ 316 new_conf = data->conf; 317 if (data->temp < data->temp_min) 318 new_conf &= ~DS1621_ALARM_TEMP_LOW; 319 if (data->temp > data->temp_max) 320 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 321 if (data->conf != new_conf) 322 ds1621_write_value(client, DS1621_REG_CONF, 323 new_conf); 324 325 data->last_updated = jiffies; 326 data->valid = 1; 327 } 328 329 up(&data->update_lock); 330 331 return data; 332 } 333 334 static int __init ds1621_init(void) 335 { 336 return i2c_add_driver(&ds1621_driver); 337 } 338 339 static void __exit ds1621_exit(void) 340 { 341 i2c_del_driver(&ds1621_driver); 342 } 343 344 345 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 346 MODULE_DESCRIPTION("DS1621 driver"); 347 MODULE_LICENSE("GPL"); 348 349 module_init(ds1621_init); 350 module_exit(ds1621_exit); 351