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 i2c_client client; 76 struct device *hwmon_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[3]; /* 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 .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 SMBus standard. */ 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 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) 113 { 114 if (reg == DS1621_REG_CONF) 115 return i2c_smbus_write_byte_data(client, reg, value); 116 else 117 return i2c_smbus_write_word_data(client, reg, swab16(value)); 118 } 119 120 static void ds1621_init_client(struct i2c_client *client) 121 { 122 int reg = ds1621_read_value(client, DS1621_REG_CONF); 123 /* switch to continuous conversion mode */ 124 reg &= ~ DS1621_REG_CONFIG_1SHOT; 125 126 /* setup output polarity */ 127 if (polarity == 0) 128 reg &= ~DS1621_REG_CONFIG_POLARITY; 129 else if (polarity == 1) 130 reg |= DS1621_REG_CONFIG_POLARITY; 131 132 ds1621_write_value(client, DS1621_REG_CONF, reg); 133 134 /* start conversion */ 135 i2c_smbus_write_byte(client, DS1621_COM_START); 136 } 137 138 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 139 char *buf) 140 { 141 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 142 struct ds1621_data *data = ds1621_update_client(dev); 143 return sprintf(buf, "%d\n", 144 LM75_TEMP_FROM_REG(data->temp[attr->index])); 145 } 146 147 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 148 const char *buf, size_t count) 149 { 150 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 151 struct i2c_client *client = to_i2c_client(dev); 152 struct ds1621_data *data = ds1621_update_client(dev); 153 u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10)); 154 155 mutex_lock(&data->update_lock); 156 data->temp[attr->index] = val; 157 ds1621_write_value(client, DS1621_REG_TEMP[attr->index], 158 data->temp[attr->index]); 159 mutex_unlock(&data->update_lock); 160 return count; 161 } 162 163 static ssize_t show_alarms(struct device *dev, struct device_attribute *da, 164 char *buf) 165 { 166 struct ds1621_data *data = ds1621_update_client(dev); 167 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 168 } 169 170 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 171 char *buf) 172 { 173 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 174 struct ds1621_data *data = ds1621_update_client(dev); 175 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 176 } 177 178 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 179 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 180 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 181 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 182 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 183 DS1621_ALARM_TEMP_LOW); 184 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 185 DS1621_ALARM_TEMP_HIGH); 186 187 static struct attribute *ds1621_attributes[] = { 188 &sensor_dev_attr_temp1_input.dev_attr.attr, 189 &sensor_dev_attr_temp1_min.dev_attr.attr, 190 &sensor_dev_attr_temp1_max.dev_attr.attr, 191 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 192 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 193 &dev_attr_alarms.attr, 194 NULL 195 }; 196 197 static const struct attribute_group ds1621_group = { 198 .attrs = ds1621_attributes, 199 }; 200 201 202 static int ds1621_attach_adapter(struct i2c_adapter *adapter) 203 { 204 if (!(adapter->class & I2C_CLASS_HWMON)) 205 return 0; 206 return i2c_probe(adapter, &addr_data, ds1621_detect); 207 } 208 209 /* This function is called by i2c_probe */ 210 static int ds1621_detect(struct i2c_adapter *adapter, int address, 211 int kind) 212 { 213 int conf, temp; 214 struct i2c_client *client; 215 struct ds1621_data *data; 216 int i, err = 0; 217 218 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 219 | I2C_FUNC_SMBUS_WORD_DATA 220 | I2C_FUNC_SMBUS_WRITE_BYTE)) 221 goto exit; 222 223 /* OK. For now, we presume we have a valid client. We now create the 224 client structure, even though we cannot fill it completely yet. 225 But it allows us to access ds1621_{read,write}_value. */ 226 if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) { 227 err = -ENOMEM; 228 goto exit; 229 } 230 231 client = &data->client; 232 i2c_set_clientdata(client, data); 233 client->addr = address; 234 client->adapter = adapter; 235 client->driver = &ds1621_driver; 236 237 /* Now, we do the remaining detection. It is lousy. */ 238 if (kind < 0) { 239 /* The NVB bit should be low if no EEPROM write has been 240 requested during the latest 10ms, which is highly 241 improbable in our case. */ 242 conf = ds1621_read_value(client, DS1621_REG_CONF); 243 if (conf & DS1621_REG_CONFIG_NVB) 244 goto exit_free; 245 /* The 7 lowest bits of a temperature should always be 0. */ 246 for (i = 0; i < ARRAY_SIZE(data->temp); i++) { 247 temp = ds1621_read_value(client, DS1621_REG_TEMP[i]); 248 if (temp & 0x007f) 249 goto exit_free; 250 } 251 } 252 253 /* Fill in remaining client fields and put it into the global list */ 254 strlcpy(client->name, "ds1621", I2C_NAME_SIZE); 255 mutex_init(&data->update_lock); 256 257 /* Tell the I2C layer a new client has arrived */ 258 if ((err = i2c_attach_client(client))) 259 goto exit_free; 260 261 /* Initialize the DS1621 chip */ 262 ds1621_init_client(client); 263 264 /* Register sysfs hooks */ 265 if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group))) 266 goto exit_detach; 267 268 data->hwmon_dev = hwmon_device_register(&client->dev); 269 if (IS_ERR(data->hwmon_dev)) { 270 err = PTR_ERR(data->hwmon_dev); 271 goto exit_remove_files; 272 } 273 274 return 0; 275 276 exit_remove_files: 277 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 278 exit_detach: 279 i2c_detach_client(client); 280 exit_free: 281 kfree(data); 282 exit: 283 return err; 284 } 285 286 static int ds1621_detach_client(struct i2c_client *client) 287 { 288 struct ds1621_data *data = i2c_get_clientdata(client); 289 int err; 290 291 hwmon_device_unregister(data->hwmon_dev); 292 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 293 294 if ((err = i2c_detach_client(client))) 295 return err; 296 297 kfree(data); 298 299 return 0; 300 } 301 302 303 static struct ds1621_data *ds1621_update_client(struct device *dev) 304 { 305 struct i2c_client *client = to_i2c_client(dev); 306 struct ds1621_data *data = i2c_get_clientdata(client); 307 u8 new_conf; 308 309 mutex_lock(&data->update_lock); 310 311 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 312 || !data->valid) { 313 int i; 314 315 dev_dbg(&client->dev, "Starting ds1621 update\n"); 316 317 data->conf = ds1621_read_value(client, DS1621_REG_CONF); 318 319 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 320 data->temp[i] = ds1621_read_value(client, 321 DS1621_REG_TEMP[i]); 322 323 /* reset alarms if necessary */ 324 new_conf = data->conf; 325 if (data->temp[0] > data->temp[1]) /* input > min */ 326 new_conf &= ~DS1621_ALARM_TEMP_LOW; 327 if (data->temp[0] < data->temp[2]) /* input < max */ 328 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 329 if (data->conf != new_conf) 330 ds1621_write_value(client, DS1621_REG_CONF, 331 new_conf); 332 333 data->last_updated = jiffies; 334 data->valid = 1; 335 } 336 337 mutex_unlock(&data->update_lock); 338 339 return data; 340 } 341 342 static int __init ds1621_init(void) 343 { 344 return i2c_add_driver(&ds1621_driver); 345 } 346 347 static void __exit ds1621_exit(void) 348 { 349 i2c_del_driver(&ds1621_driver); 350 } 351 352 353 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 354 MODULE_DESCRIPTION("DS1621 driver"); 355 MODULE_LICENSE("GPL"); 356 357 module_init(ds1621_init); 358 module_exit(ds1621_exit); 359