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 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 .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 SMBus standard. */ 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 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) 114 { 115 if (reg == DS1621_REG_CONF) 116 return i2c_smbus_write_byte_data(client, reg, value); 117 else 118 return i2c_smbus_write_word_data(client, reg, swab16(value)); 119 } 120 121 static void ds1621_init_client(struct i2c_client *client) 122 { 123 int reg = ds1621_read_value(client, DS1621_REG_CONF); 124 /* switch to continuous conversion mode */ 125 reg &= ~ DS1621_REG_CONFIG_1SHOT; 126 127 /* setup output polarity */ 128 if (polarity == 0) 129 reg &= ~DS1621_REG_CONFIG_POLARITY; 130 else if (polarity == 1) 131 reg |= DS1621_REG_CONFIG_POLARITY; 132 133 ds1621_write_value(client, DS1621_REG_CONF, reg); 134 135 /* start conversion */ 136 i2c_smbus_write_byte(client, DS1621_COM_START); 137 } 138 139 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 140 char *buf) 141 { 142 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 143 struct ds1621_data *data = ds1621_update_client(dev); 144 return sprintf(buf, "%d\n", 145 LM75_TEMP_FROM_REG(data->temp[attr->index])); 146 } 147 148 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 149 const char *buf, size_t count) 150 { 151 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 152 struct i2c_client *client = to_i2c_client(dev); 153 struct ds1621_data *data = ds1621_update_client(dev); 154 u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10)); 155 156 mutex_lock(&data->update_lock); 157 data->temp[attr->index] = val; 158 ds1621_write_value(client, DS1621_REG_TEMP[attr->index], 159 data->temp[attr->index]); 160 mutex_unlock(&data->update_lock); 161 return count; 162 } 163 164 static ssize_t show_alarms(struct device *dev, struct device_attribute *da, 165 char *buf) 166 { 167 struct ds1621_data *data = ds1621_update_client(dev); 168 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 169 } 170 171 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 172 char *buf) 173 { 174 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 175 struct ds1621_data *data = ds1621_update_client(dev); 176 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 177 } 178 179 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 180 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 181 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 182 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 183 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 184 DS1621_ALARM_TEMP_LOW); 185 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 186 DS1621_ALARM_TEMP_HIGH); 187 188 static struct attribute *ds1621_attributes[] = { 189 &sensor_dev_attr_temp1_input.dev_attr.attr, 190 &sensor_dev_attr_temp1_min.dev_attr.attr, 191 &sensor_dev_attr_temp1_max.dev_attr.attr, 192 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 193 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 194 &dev_attr_alarms.attr, 195 NULL 196 }; 197 198 static const struct attribute_group ds1621_group = { 199 .attrs = ds1621_attributes, 200 }; 201 202 203 static int ds1621_attach_adapter(struct i2c_adapter *adapter) 204 { 205 if (!(adapter->class & I2C_CLASS_HWMON)) 206 return 0; 207 return i2c_probe(adapter, &addr_data, ds1621_detect); 208 } 209 210 /* This function is called by i2c_probe */ 211 static int ds1621_detect(struct i2c_adapter *adapter, int address, 212 int kind) 213 { 214 int conf, temp; 215 struct i2c_client *client; 216 struct ds1621_data *data; 217 int i, err = 0; 218 219 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 220 | I2C_FUNC_SMBUS_WORD_DATA 221 | I2C_FUNC_SMBUS_WRITE_BYTE)) 222 goto exit; 223 224 /* OK. For now, we presume we have a valid client. We now create the 225 client structure, even though we cannot fill it completely yet. 226 But it allows us to access ds1621_{read,write}_value. */ 227 if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) { 228 err = -ENOMEM; 229 goto exit; 230 } 231 232 client = &data->client; 233 i2c_set_clientdata(client, data); 234 client->addr = address; 235 client->adapter = adapter; 236 client->driver = &ds1621_driver; 237 238 /* Now, we do the remaining detection. It is lousy. */ 239 if (kind < 0) { 240 /* The NVB bit should be low if no EEPROM write has been 241 requested during the latest 10ms, which is highly 242 improbable in our case. */ 243 conf = ds1621_read_value(client, DS1621_REG_CONF); 244 if (conf & DS1621_REG_CONFIG_NVB) 245 goto exit_free; 246 /* The 7 lowest bits of a temperature should always be 0. */ 247 for (i = 0; i < ARRAY_SIZE(data->temp); i++) { 248 temp = ds1621_read_value(client, DS1621_REG_TEMP[i]); 249 if (temp & 0x007f) 250 goto exit_free; 251 } 252 } 253 254 /* Fill in remaining client fields and put it into the global list */ 255 strlcpy(client->name, "ds1621", I2C_NAME_SIZE); 256 mutex_init(&data->update_lock); 257 258 /* Tell the I2C layer a new client has arrived */ 259 if ((err = i2c_attach_client(client))) 260 goto exit_free; 261 262 /* Initialize the DS1621 chip */ 263 ds1621_init_client(client); 264 265 /* Register sysfs hooks */ 266 if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group))) 267 goto exit_detach; 268 269 data->hwmon_dev = hwmon_device_register(&client->dev); 270 if (IS_ERR(data->hwmon_dev)) { 271 err = PTR_ERR(data->hwmon_dev); 272 goto exit_remove_files; 273 } 274 275 return 0; 276 277 exit_remove_files: 278 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 279 exit_detach: 280 i2c_detach_client(client); 281 exit_free: 282 kfree(data); 283 exit: 284 return err; 285 } 286 287 static int ds1621_detach_client(struct i2c_client *client) 288 { 289 struct ds1621_data *data = i2c_get_clientdata(client); 290 int err; 291 292 hwmon_device_unregister(data->hwmon_dev); 293 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 294 295 if ((err = i2c_detach_client(client))) 296 return err; 297 298 kfree(data); 299 300 return 0; 301 } 302 303 304 static struct ds1621_data *ds1621_update_client(struct device *dev) 305 { 306 struct i2c_client *client = to_i2c_client(dev); 307 struct ds1621_data *data = i2c_get_clientdata(client); 308 u8 new_conf; 309 310 mutex_lock(&data->update_lock); 311 312 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 313 || !data->valid) { 314 int i; 315 316 dev_dbg(&client->dev, "Starting ds1621 update\n"); 317 318 data->conf = ds1621_read_value(client, DS1621_REG_CONF); 319 320 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 321 data->temp[i] = ds1621_read_value(client, 322 DS1621_REG_TEMP[i]); 323 324 /* reset alarms if necessary */ 325 new_conf = data->conf; 326 if (data->temp[0] > data->temp[1]) /* input > min */ 327 new_conf &= ~DS1621_ALARM_TEMP_LOW; 328 if (data->temp[0] < data->temp[2]) /* input < max */ 329 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 330 if (data->conf != new_conf) 331 ds1621_write_value(client, DS1621_REG_CONF, 332 new_conf); 333 334 data->last_updated = jiffies; 335 data->valid = 1; 336 } 337 338 mutex_unlock(&data->update_lock); 339 340 return data; 341 } 342 343 static int __init ds1621_init(void) 344 { 345 return i2c_add_driver(&ds1621_driver); 346 } 347 348 static void __exit ds1621_exit(void) 349 { 350 i2c_del_driver(&ds1621_driver); 351 } 352 353 354 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 355 MODULE_DESCRIPTION("DS1621 driver"); 356 MODULE_LICENSE("GPL"); 357 358 module_init(ds1621_init); 359 module_exit(ds1621_exit); 360