1 /* 2 * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware 3 * monitoring 4 * Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org> 5 * 6 * Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made 7 * by Winbond. It reports a single external temperature with a 1 deg 8 * resolution and a 3 deg accuracy. Datasheet can be obtained from 9 * Winbond's website at: 10 * http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf 11 * 12 * Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare 13 * <khali@linux-fr.org>. 14 * 15 * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read 16 * error handling mechanism. 17 * 18 * This program is free software; you can redistribute it and/or modify 19 * it under the terms of the GNU General Public License as published by 20 * the Free Software Foundation; either version 2 of the License, or 21 * (at your option) any later version. 22 * 23 * This program is distributed in the hope that it will be useful, 24 * but WITHOUT ANY WARRANTY; without even the implied warranty of 25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 26 * GNU General Public License for more details. 27 * 28 * You should have received a copy of the GNU General Public License 29 * along with this program; if not, write to the Free Software 30 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 31 */ 32 33 #include <linux/module.h> 34 #include <linux/delay.h> 35 #include <linux/init.h> 36 #include <linux/slab.h> 37 #include <linux/jiffies.h> 38 #include <linux/i2c.h> 39 #include <linux/hwmon.h> 40 #include <linux/hwmon-sysfs.h> 41 #include <linux/err.h> 42 #include <linux/mutex.h> 43 44 /* How many retries on register read error */ 45 #define MAX_RETRIES 5 46 47 /* 48 * Address to scan 49 * Address is fully defined internally and cannot be changed. 50 */ 51 52 static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END }; 53 54 /* 55 * Insmod parameters 56 */ 57 58 I2C_CLIENT_INSMOD_1(w83l785ts); 59 60 /* 61 * The W83L785TS-S registers 62 * Manufacturer ID is 0x5CA3 for Winbond. 63 */ 64 65 #define W83L785TS_REG_MAN_ID1 0x4D 66 #define W83L785TS_REG_MAN_ID2 0x4C 67 #define W83L785TS_REG_CHIP_ID 0x4E 68 #define W83L785TS_REG_CONFIG 0x40 69 #define W83L785TS_REG_TYPE 0x52 70 #define W83L785TS_REG_TEMP 0x27 71 #define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */ 72 73 /* 74 * Conversions 75 * The W83L785TS-S uses signed 8-bit values. 76 */ 77 78 #define TEMP_FROM_REG(val) ((val) * 1000) 79 80 /* 81 * Functions declaration 82 */ 83 84 static int w83l785ts_probe(struct i2c_client *client, 85 const struct i2c_device_id *id); 86 static int w83l785ts_detect(struct i2c_client *client, int kind, 87 struct i2c_board_info *info); 88 static int w83l785ts_remove(struct i2c_client *client); 89 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval); 90 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev); 91 92 /* 93 * Driver data (common to all clients) 94 */ 95 96 static const struct i2c_device_id w83l785ts_id[] = { 97 { "w83l785ts", w83l785ts }, 98 { } 99 }; 100 MODULE_DEVICE_TABLE(i2c, w83l785ts_id); 101 102 static struct i2c_driver w83l785ts_driver = { 103 .class = I2C_CLASS_HWMON, 104 .driver = { 105 .name = "w83l785ts", 106 }, 107 .probe = w83l785ts_probe, 108 .remove = w83l785ts_remove, 109 .id_table = w83l785ts_id, 110 .detect = w83l785ts_detect, 111 .address_data = &addr_data, 112 }; 113 114 /* 115 * Client data (each client gets its own) 116 */ 117 118 struct w83l785ts_data { 119 struct device *hwmon_dev; 120 struct mutex update_lock; 121 char valid; /* zero until following fields are valid */ 122 unsigned long last_updated; /* in jiffies */ 123 124 /* registers values */ 125 s8 temp[2]; /* 0: input 126 1: critical limit */ 127 }; 128 129 /* 130 * Sysfs stuff 131 */ 132 133 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, 134 char *buf) 135 { 136 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 137 struct w83l785ts_data *data = w83l785ts_update_device(dev); 138 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])); 139 } 140 141 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 142 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1); 143 144 /* 145 * Real code 146 */ 147 148 /* Return 0 if detection is successful, -ENODEV otherwise */ 149 static int w83l785ts_detect(struct i2c_client *new_client, int kind, 150 struct i2c_board_info *info) 151 { 152 struct i2c_adapter *adapter = new_client->adapter; 153 154 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 155 return -ENODEV; 156 157 /* 158 * Now we do the remaining detection. A negative kind means that 159 * the driver was loaded with no force parameter (default), so we 160 * must both detect and identify the chip (actually there is only 161 * one possible kind of chip for now, W83L785TS-S). A zero kind means 162 * that the driver was loaded with the force parameter, the detection 163 * step shall be skipped. A positive kind means that the driver 164 * was loaded with the force parameter and a given kind of chip is 165 * requested, so both the detection and the identification steps 166 * are skipped. 167 */ 168 if (kind < 0) { /* detection */ 169 if (((w83l785ts_read_value(new_client, 170 W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00) 171 || ((w83l785ts_read_value(new_client, 172 W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) { 173 dev_dbg(&adapter->dev, 174 "W83L785TS-S detection failed at 0x%02x.\n", 175 new_client->addr); 176 return -ENODEV; 177 } 178 } 179 180 if (kind <= 0) { /* identification */ 181 u16 man_id; 182 u8 chip_id; 183 184 man_id = (w83l785ts_read_value(new_client, 185 W83L785TS_REG_MAN_ID1, 0) << 8) + 186 w83l785ts_read_value(new_client, 187 W83L785TS_REG_MAN_ID2, 0); 188 chip_id = w83l785ts_read_value(new_client, 189 W83L785TS_REG_CHIP_ID, 0); 190 191 if (man_id == 0x5CA3) { /* Winbond */ 192 if (chip_id == 0x70) { /* W83L785TS-S */ 193 kind = w83l785ts; 194 } 195 } 196 197 if (kind <= 0) { /* identification failed */ 198 dev_info(&adapter->dev, 199 "Unsupported chip (man_id=0x%04X, " 200 "chip_id=0x%02X).\n", man_id, chip_id); 201 return -ENODEV; 202 } 203 } 204 205 strlcpy(info->type, "w83l785ts", I2C_NAME_SIZE); 206 207 return 0; 208 } 209 210 static int w83l785ts_probe(struct i2c_client *new_client, 211 const struct i2c_device_id *id) 212 { 213 struct w83l785ts_data *data; 214 int err = 0; 215 216 data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL); 217 if (!data) { 218 err = -ENOMEM; 219 goto exit; 220 } 221 222 i2c_set_clientdata(new_client, data); 223 data->valid = 0; 224 mutex_init(&data->update_lock); 225 226 /* Default values in case the first read fails (unlikely). */ 227 data->temp[1] = data->temp[0] = 0; 228 229 /* 230 * Initialize the W83L785TS chip 231 * Nothing yet, assume it is already started. 232 */ 233 234 err = device_create_file(&new_client->dev, 235 &sensor_dev_attr_temp1_input.dev_attr); 236 if (err) 237 goto exit_remove; 238 239 err = device_create_file(&new_client->dev, 240 &sensor_dev_attr_temp1_max.dev_attr); 241 if (err) 242 goto exit_remove; 243 244 /* Register sysfs hooks */ 245 data->hwmon_dev = hwmon_device_register(&new_client->dev); 246 if (IS_ERR(data->hwmon_dev)) { 247 err = PTR_ERR(data->hwmon_dev); 248 goto exit_remove; 249 } 250 251 return 0; 252 253 exit_remove: 254 device_remove_file(&new_client->dev, 255 &sensor_dev_attr_temp1_input.dev_attr); 256 device_remove_file(&new_client->dev, 257 &sensor_dev_attr_temp1_max.dev_attr); 258 kfree(data); 259 exit: 260 return err; 261 } 262 263 static int w83l785ts_remove(struct i2c_client *client) 264 { 265 struct w83l785ts_data *data = i2c_get_clientdata(client); 266 267 hwmon_device_unregister(data->hwmon_dev); 268 device_remove_file(&client->dev, 269 &sensor_dev_attr_temp1_input.dev_attr); 270 device_remove_file(&client->dev, 271 &sensor_dev_attr_temp1_max.dev_attr); 272 273 kfree(data); 274 return 0; 275 } 276 277 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval) 278 { 279 int value, i; 280 struct device *dev; 281 const char *prefix; 282 283 /* We might be called during detection, at which point the client 284 isn't yet fully initialized, so we can't use dev_dbg on it */ 285 if (i2c_get_clientdata(client)) { 286 dev = &client->dev; 287 prefix = ""; 288 } else { 289 dev = &client->adapter->dev; 290 prefix = "w83l785ts: "; 291 } 292 293 /* Frequent read errors have been reported on Asus boards, so we 294 * retry on read errors. If it still fails (unlikely), return the 295 * default value requested by the caller. */ 296 for (i = 1; i <= MAX_RETRIES; i++) { 297 value = i2c_smbus_read_byte_data(client, reg); 298 if (value >= 0) { 299 dev_dbg(dev, "%sRead 0x%02x from register 0x%02x.\n", 300 prefix, value, reg); 301 return value; 302 } 303 dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i); 304 msleep(i); 305 } 306 307 dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix, 308 reg); 309 return defval; 310 } 311 312 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev) 313 { 314 struct i2c_client *client = to_i2c_client(dev); 315 struct w83l785ts_data *data = i2c_get_clientdata(client); 316 317 mutex_lock(&data->update_lock); 318 319 if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) { 320 dev_dbg(&client->dev, "Updating w83l785ts data.\n"); 321 data->temp[0] = w83l785ts_read_value(client, 322 W83L785TS_REG_TEMP, data->temp[0]); 323 data->temp[1] = w83l785ts_read_value(client, 324 W83L785TS_REG_TEMP_OVER, data->temp[1]); 325 326 data->last_updated = jiffies; 327 data->valid = 1; 328 } 329 330 mutex_unlock(&data->update_lock); 331 332 return data; 333 } 334 335 static int __init sensors_w83l785ts_init(void) 336 { 337 return i2c_add_driver(&w83l785ts_driver); 338 } 339 340 static void __exit sensors_w83l785ts_exit(void) 341 { 342 i2c_del_driver(&w83l785ts_driver); 343 } 344 345 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); 346 MODULE_DESCRIPTION("W83L785TS-S driver"); 347 MODULE_LICENSE("GPL"); 348 349 module_init(sensors_w83l785ts_init); 350 module_exit(sensors_w83l785ts_exit); 351