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/i2c-sensor.h> 40 41 /* How many retries on register read error */ 42 #define MAX_RETRIES 5 43 44 /* 45 * Address to scan 46 * Address is fully defined internally and cannot be changed. 47 */ 48 49 static unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END }; 50 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; 51 52 /* 53 * Insmod parameters 54 */ 55 56 SENSORS_INSMOD_1(w83l785ts); 57 58 /* 59 * The W83L785TS-S registers 60 * Manufacturer ID is 0x5CA3 for Winbond. 61 */ 62 63 #define W83L785TS_REG_MAN_ID1 0x4D 64 #define W83L785TS_REG_MAN_ID2 0x4C 65 #define W83L785TS_REG_CHIP_ID 0x4E 66 #define W83L785TS_REG_CONFIG 0x40 67 #define W83L785TS_REG_TYPE 0x52 68 #define W83L785TS_REG_TEMP 0x27 69 #define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */ 70 71 /* 72 * Conversions 73 * The W83L785TS-S uses signed 8-bit values. 74 */ 75 76 #define TEMP_FROM_REG(val) ((val & 0x80 ? val-0x100 : val) * 1000) 77 78 /* 79 * Functions declaration 80 */ 81 82 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter); 83 static int w83l785ts_detect(struct i2c_adapter *adapter, int address, 84 int kind); 85 static int w83l785ts_detach_client(struct i2c_client *client); 86 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval); 87 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev); 88 89 /* 90 * Driver data (common to all clients) 91 */ 92 93 static struct i2c_driver w83l785ts_driver = { 94 .owner = THIS_MODULE, 95 .name = "w83l785ts", 96 .id = I2C_DRIVERID_W83L785TS, 97 .flags = I2C_DF_NOTIFY, 98 .attach_adapter = w83l785ts_attach_adapter, 99 .detach_client = w83l785ts_detach_client, 100 }; 101 102 /* 103 * Client data (each client gets its own) 104 */ 105 106 struct w83l785ts_data { 107 struct i2c_client client; 108 struct semaphore update_lock; 109 char valid; /* zero until following fields are valid */ 110 unsigned long last_updated; /* in jiffies */ 111 112 /* registers values */ 113 u8 temp, temp_over; 114 }; 115 116 /* 117 * Sysfs stuff 118 */ 119 120 static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf) 121 { 122 struct w83l785ts_data *data = w83l785ts_update_device(dev); 123 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp)); 124 } 125 126 static ssize_t show_temp_over(struct device *dev, struct device_attribute *attr, char *buf) 127 { 128 struct w83l785ts_data *data = w83l785ts_update_device(dev); 129 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over)); 130 } 131 132 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL); 133 static DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_over, NULL); 134 135 /* 136 * Real code 137 */ 138 139 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter) 140 { 141 if (!(adapter->class & I2C_CLASS_HWMON)) 142 return 0; 143 return i2c_detect(adapter, &addr_data, w83l785ts_detect); 144 } 145 146 /* 147 * The following function does more than just detection. If detection 148 * succeeds, it also registers the new chip. 149 */ 150 static int w83l785ts_detect(struct i2c_adapter *adapter, int address, int kind) 151 { 152 struct i2c_client *new_client; 153 struct w83l785ts_data *data; 154 int err = 0; 155 156 157 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 158 goto exit; 159 160 if (!(data = kmalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) { 161 err = -ENOMEM; 162 goto exit; 163 } 164 memset(data, 0, sizeof(struct w83l785ts_data)); 165 166 167 /* The common I2C client data is placed right before the 168 * W83L785TS-specific data. */ 169 new_client = &data->client; 170 i2c_set_clientdata(new_client, data); 171 new_client->addr = address; 172 new_client->adapter = adapter; 173 new_client->driver = &w83l785ts_driver; 174 new_client->flags = 0; 175 176 /* 177 * Now we do the remaining detection. A negative kind means that 178 * the driver was loaded with no force parameter (default), so we 179 * must both detect and identify the chip (actually there is only 180 * one possible kind of chip for now, W83L785TS-S). A zero kind means 181 * that the driver was loaded with the force parameter, the detection 182 * step shall be skipped. A positive kind means that the driver 183 * was loaded with the force parameter and a given kind of chip is 184 * requested, so both the detection and the identification steps 185 * are skipped. 186 */ 187 if (kind < 0) { /* detection */ 188 if (((w83l785ts_read_value(new_client, 189 W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00) 190 || ((w83l785ts_read_value(new_client, 191 W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) { 192 dev_dbg(&adapter->dev, 193 "W83L785TS-S detection failed at 0x%02x.\n", 194 address); 195 goto exit_free; 196 } 197 } 198 199 if (kind <= 0) { /* identification */ 200 u16 man_id; 201 u8 chip_id; 202 203 man_id = (w83l785ts_read_value(new_client, 204 W83L785TS_REG_MAN_ID1, 0) << 8) + 205 w83l785ts_read_value(new_client, 206 W83L785TS_REG_MAN_ID2, 0); 207 chip_id = w83l785ts_read_value(new_client, 208 W83L785TS_REG_CHIP_ID, 0); 209 210 if (man_id == 0x5CA3) { /* Winbond */ 211 if (chip_id == 0x70) { /* W83L785TS-S */ 212 kind = w83l785ts; 213 } 214 } 215 216 if (kind <= 0) { /* identification failed */ 217 dev_info(&adapter->dev, 218 "Unsupported chip (man_id=0x%04X, " 219 "chip_id=0x%02X).\n", man_id, chip_id); 220 goto exit_free; 221 } 222 } 223 224 /* We can fill in the remaining client fields. */ 225 strlcpy(new_client->name, "w83l785ts", I2C_NAME_SIZE); 226 data->valid = 0; 227 init_MUTEX(&data->update_lock); 228 229 /* Default values in case the first read fails (unlikely). */ 230 data->temp_over = data->temp = 0; 231 232 /* Tell the I2C layer a new client has arrived. */ 233 if ((err = i2c_attach_client(new_client))) 234 goto exit_free; 235 236 /* 237 * Initialize the W83L785TS chip 238 * Nothing yet, assume it is already started. 239 */ 240 241 /* Register sysfs hooks */ 242 device_create_file(&new_client->dev, &dev_attr_temp1_input); 243 device_create_file(&new_client->dev, &dev_attr_temp1_max); 244 245 return 0; 246 247 exit_free: 248 kfree(data); 249 exit: 250 return err; 251 } 252 253 static int w83l785ts_detach_client(struct i2c_client *client) 254 { 255 int err; 256 257 if ((err = i2c_detach_client(client))) { 258 dev_err(&client->dev, "Client deregistration failed, " 259 "client not detached.\n"); 260 return err; 261 } 262 263 kfree(i2c_get_clientdata(client)); 264 return 0; 265 } 266 267 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval) 268 { 269 int value, i; 270 271 /* Frequent read errors have been reported on Asus boards, so we 272 * retry on read errors. If it still fails (unlikely), return the 273 * default value requested by the caller. */ 274 for (i = 1; i <= MAX_RETRIES; i++) { 275 value = i2c_smbus_read_byte_data(client, reg); 276 if (value >= 0) { 277 dev_dbg(&client->dev, "Read 0x%02x from register " 278 "0x%02x.\n", value, reg); 279 return value; 280 } 281 dev_dbg(&client->dev, "Read failed, will retry in %d.\n", i); 282 msleep(i); 283 } 284 285 dev_err(&client->dev, "Couldn't read value from register 0x%02x. " 286 "Please report.\n", reg); 287 return defval; 288 } 289 290 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev) 291 { 292 struct i2c_client *client = to_i2c_client(dev); 293 struct w83l785ts_data *data = i2c_get_clientdata(client); 294 295 down(&data->update_lock); 296 297 if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) { 298 dev_dbg(&client->dev, "Updating w83l785ts data.\n"); 299 data->temp = w83l785ts_read_value(client, 300 W83L785TS_REG_TEMP, data->temp); 301 data->temp_over = w83l785ts_read_value(client, 302 W83L785TS_REG_TEMP_OVER, data->temp_over); 303 304 data->last_updated = jiffies; 305 data->valid = 1; 306 } 307 308 up(&data->update_lock); 309 310 return data; 311 } 312 313 static int __init sensors_w83l785ts_init(void) 314 { 315 return i2c_add_driver(&w83l785ts_driver); 316 } 317 318 static void __exit sensors_w83l785ts_exit(void) 319 { 320 i2c_del_driver(&w83l785ts_driver); 321 } 322 323 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); 324 MODULE_DESCRIPTION("W83L785TS-S driver"); 325 MODULE_LICENSE("GPL"); 326 327 module_init(sensors_w83l785ts_init); 328 module_exit(sensors_w83l785ts_exit); 329