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_attach_adapter(struct i2c_adapter *adapter); 85 static int w83l785ts_detect(struct i2c_adapter *adapter, int address, 86 int kind); 87 static int w83l785ts_detach_client(struct i2c_client *client); 88 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval); 89 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev); 90 91 /* 92 * Driver data (common to all clients) 93 */ 94 95 static struct i2c_driver w83l785ts_driver = { 96 .driver = { 97 .name = "w83l785ts", 98 }, 99 .attach_adapter = w83l785ts_attach_adapter, 100 .detach_client = w83l785ts_detach_client, 101 }; 102 103 /* 104 * Client data (each client gets its own) 105 */ 106 107 struct w83l785ts_data { 108 struct i2c_client client; 109 struct device *hwmon_dev; 110 struct mutex update_lock; 111 char valid; /* zero until following fields are valid */ 112 unsigned long last_updated; /* in jiffies */ 113 114 /* registers values */ 115 s8 temp[2]; /* 0: input 116 1: critical limit */ 117 }; 118 119 /* 120 * Sysfs stuff 121 */ 122 123 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, 124 char *buf) 125 { 126 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 127 struct w83l785ts_data *data = w83l785ts_update_device(dev); 128 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])); 129 } 130 131 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 132 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1); 133 134 /* 135 * Real code 136 */ 137 138 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter) 139 { 140 if (!(adapter->class & I2C_CLASS_HWMON)) 141 return 0; 142 return i2c_probe(adapter, &addr_data, w83l785ts_detect); 143 } 144 145 /* 146 * The following function does more than just detection. If detection 147 * succeeds, it also registers the new chip. 148 */ 149 static int w83l785ts_detect(struct i2c_adapter *adapter, int address, int kind) 150 { 151 struct i2c_client *new_client; 152 struct w83l785ts_data *data; 153 int err = 0; 154 155 156 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 157 goto exit; 158 159 if (!(data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) { 160 err = -ENOMEM; 161 goto exit; 162 } 163 164 /* The common I2C client data is placed right before the 165 * W83L785TS-specific data. */ 166 new_client = &data->client; 167 i2c_set_clientdata(new_client, data); 168 new_client->addr = address; 169 new_client->adapter = adapter; 170 new_client->driver = &w83l785ts_driver; 171 new_client->flags = 0; 172 173 /* 174 * Now we do the remaining detection. A negative kind means that 175 * the driver was loaded with no force parameter (default), so we 176 * must both detect and identify the chip (actually there is only 177 * one possible kind of chip for now, W83L785TS-S). A zero kind means 178 * that the driver was loaded with the force parameter, the detection 179 * step shall be skipped. A positive kind means that the driver 180 * was loaded with the force parameter and a given kind of chip is 181 * requested, so both the detection and the identification steps 182 * are skipped. 183 */ 184 if (kind < 0) { /* detection */ 185 if (((w83l785ts_read_value(new_client, 186 W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00) 187 || ((w83l785ts_read_value(new_client, 188 W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) { 189 dev_dbg(&adapter->dev, 190 "W83L785TS-S detection failed at 0x%02x.\n", 191 address); 192 goto exit_free; 193 } 194 } 195 196 if (kind <= 0) { /* identification */ 197 u16 man_id; 198 u8 chip_id; 199 200 man_id = (w83l785ts_read_value(new_client, 201 W83L785TS_REG_MAN_ID1, 0) << 8) + 202 w83l785ts_read_value(new_client, 203 W83L785TS_REG_MAN_ID2, 0); 204 chip_id = w83l785ts_read_value(new_client, 205 W83L785TS_REG_CHIP_ID, 0); 206 207 if (man_id == 0x5CA3) { /* Winbond */ 208 if (chip_id == 0x70) { /* W83L785TS-S */ 209 kind = w83l785ts; 210 } 211 } 212 213 if (kind <= 0) { /* identification failed */ 214 dev_info(&adapter->dev, 215 "Unsupported chip (man_id=0x%04X, " 216 "chip_id=0x%02X).\n", man_id, chip_id); 217 goto exit_free; 218 } 219 } 220 221 /* We can fill in the remaining client fields. */ 222 strlcpy(new_client->name, "w83l785ts", I2C_NAME_SIZE); 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 /* Tell the I2C layer a new client has arrived. */ 230 if ((err = i2c_attach_client(new_client))) 231 goto exit_free; 232 233 /* 234 * Initialize the W83L785TS chip 235 * Nothing yet, assume it is already started. 236 */ 237 238 err = device_create_file(&new_client->dev, 239 &sensor_dev_attr_temp1_input.dev_attr); 240 if (err) 241 goto exit_remove; 242 243 err = device_create_file(&new_client->dev, 244 &sensor_dev_attr_temp1_max.dev_attr); 245 if (err) 246 goto exit_remove; 247 248 /* Register sysfs hooks */ 249 data->hwmon_dev = hwmon_device_register(&new_client->dev); 250 if (IS_ERR(data->hwmon_dev)) { 251 err = PTR_ERR(data->hwmon_dev); 252 goto exit_remove; 253 } 254 255 return 0; 256 257 exit_remove: 258 device_remove_file(&new_client->dev, 259 &sensor_dev_attr_temp1_input.dev_attr); 260 device_remove_file(&new_client->dev, 261 &sensor_dev_attr_temp1_max.dev_attr); 262 i2c_detach_client(new_client); 263 exit_free: 264 kfree(data); 265 exit: 266 return err; 267 } 268 269 static int w83l785ts_detach_client(struct i2c_client *client) 270 { 271 struct w83l785ts_data *data = i2c_get_clientdata(client); 272 int err; 273 274 hwmon_device_unregister(data->hwmon_dev); 275 device_remove_file(&client->dev, 276 &sensor_dev_attr_temp1_input.dev_attr); 277 device_remove_file(&client->dev, 278 &sensor_dev_attr_temp1_max.dev_attr); 279 if ((err = i2c_detach_client(client))) 280 return err; 281 282 kfree(data); 283 return 0; 284 } 285 286 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval) 287 { 288 int value, i; 289 290 /* Frequent read errors have been reported on Asus boards, so we 291 * retry on read errors. If it still fails (unlikely), return the 292 * default value requested by the caller. */ 293 for (i = 1; i <= MAX_RETRIES; i++) { 294 value = i2c_smbus_read_byte_data(client, reg); 295 if (value >= 0) { 296 dev_dbg(&client->dev, "Read 0x%02x from register " 297 "0x%02x.\n", value, reg); 298 return value; 299 } 300 dev_dbg(&client->dev, "Read failed, will retry in %d.\n", i); 301 msleep(i); 302 } 303 304 dev_err(&client->dev, "Couldn't read value from register 0x%02x. " 305 "Please report.\n", reg); 306 return defval; 307 } 308 309 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev) 310 { 311 struct i2c_client *client = to_i2c_client(dev); 312 struct w83l785ts_data *data = i2c_get_clientdata(client); 313 314 mutex_lock(&data->update_lock); 315 316 if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) { 317 dev_dbg(&client->dev, "Updating w83l785ts data.\n"); 318 data->temp[0] = w83l785ts_read_value(client, 319 W83L785TS_REG_TEMP, data->temp[0]); 320 data->temp[1] = w83l785ts_read_value(client, 321 W83L785TS_REG_TEMP_OVER, data->temp[1]); 322 323 data->last_updated = jiffies; 324 data->valid = 1; 325 } 326 327 mutex_unlock(&data->update_lock); 328 329 return data; 330 } 331 332 static int __init sensors_w83l785ts_init(void) 333 { 334 return i2c_add_driver(&w83l785ts_driver); 335 } 336 337 static void __exit sensors_w83l785ts_exit(void) 338 { 339 i2c_del_driver(&w83l785ts_driver); 340 } 341 342 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); 343 MODULE_DESCRIPTION("W83L785TS-S driver"); 344 MODULE_LICENSE("GPL"); 345 346 module_init(sensors_w83l785ts_init); 347 module_exit(sensors_w83l785ts_exit); 348