drivers/hwmon/w83l785ts.c

   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 <<<<<<< HEAD:drivers/hwmon/w83l785ts.c
  53 static unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };
  54 =======
  55 static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };
  56 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/hwmon/w83l785ts.c
  57
  58 /*
  59  * Insmod parameters
  60  */
  61
  62 I2C_CLIENT_INSMOD_1(w83l785ts);
  63
  64 /*
  65  * The W83L785TS-S registers
  66  * Manufacturer ID is 0x5CA3 for Winbond.
  67  */
  68
  69 #define W83L785TS_REG_MAN_ID1           0x4D
  70 #define W83L785TS_REG_MAN_ID2           0x4C
  71 #define W83L785TS_REG_CHIP_ID           0x4E
  72 #define W83L785TS_REG_CONFIG            0x40
  73 #define W83L785TS_REG_TYPE              0x52
  74 #define W83L785TS_REG_TEMP              0x27
  75 #define W83L785TS_REG_TEMP_OVER         0x53 /* not sure about this one */
  76
  77 /*
  78  * Conversions
  79  * The W83L785TS-S uses signed 8-bit values.
  80  */
  81
  82 #define TEMP_FROM_REG(val)      ((val) * 1000)
  83
  84 /*
  85  * Functions declaration
  86  */
  87
  88 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter);
  89 static int w83l785ts_detect(struct i2c_adapter *adapter, int address,
  90         int kind);
  91 static int w83l785ts_detach_client(struct i2c_client *client);
  92 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
  93 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);
  94
  95 /*
  96  * Driver data (common to all clients)
  97  */
  98
  99 static struct i2c_driver w83l785ts_driver = {
 100         .driver = {
 101                 .name   = "w83l785ts",
 102         },
 103         .attach_adapter = w83l785ts_attach_adapter,
 104         .detach_client  = w83l785ts_detach_client,
 105 };
 106
 107 /*
 108  * Client data (each client gets its own)
 109  */
 110
 111 struct w83l785ts_data {
 112         struct i2c_client client;
 113         struct device *hwmon_dev;
 114         struct mutex update_lock;
 115         char valid; /* zero until following fields are valid */
 116         unsigned long last_updated; /* in jiffies */
 117
 118         /* registers values */
 119         s8 temp[2]; /* 0: input
 120                        1: critical limit */
 121 };
 122
 123 /*
 124  * Sysfs stuff
 125  */
 126
 127 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 128         char *buf)
 129 {
 130         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 131         struct w83l785ts_data *data = w83l785ts_update_device(dev);
 132         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 133 }
 134
 135 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 136 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);
 137
 138 /*
 139  * Real code
 140  */
 141
 142 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter)
 143 {
 144         if (!(adapter->class & I2C_CLASS_HWMON))
 145                 return 0;
 146         return i2c_probe(adapter, &addr_data, w83l785ts_detect);
 147 }
 148
 149 /*
 150  * The following function does more than just detection. If detection
 151  * succeeds, it also registers the new chip.
 152  */
 153 static int w83l785ts_detect(struct i2c_adapter *adapter, int address, int kind)
 154 {
 155         struct i2c_client *new_client;
 156         struct w83l785ts_data *data;
 157         int err = 0;
 158
 159
 160         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 161                 goto exit;
 162
 163         if (!(data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) {
 164                 err = -ENOMEM;
 165                 goto exit;
 166         }
 167
 168         /* The common I2C client data is placed right before the
 169          * W83L785TS-specific data. */
 170         new_client = &data->client;
 171         i2c_set_clientdata(new_client, data);
 172         new_client->addr = address;
 173         new_client->adapter = adapter;
 174         new_client->driver = &w83l785ts_driver;
 175         new_client->flags = 0;
 176
 177         /*
 178          * Now we do the remaining detection. A negative kind means that
 179          * the driver was loaded with no force parameter (default), so we
 180          * must both detect and identify the chip (actually there is only
 181          * one possible kind of chip for now, W83L785TS-S). A zero kind means
 182          * that the driver was loaded with the force parameter, the detection
 183          * step shall be skipped. A positive kind means that the driver
 184          * was loaded with the force parameter and a given kind of chip is
 185          * requested, so both the detection and the identification steps
 186          * are skipped.
 187          */
 188         if (kind < 0) { /* detection */
 189                 if (((w83l785ts_read_value(new_client,
 190                       W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00)
 191                  || ((w83l785ts_read_value(new_client,
 192                       W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) {
 193                         dev_dbg(&adapter->dev,
 194                                 "W83L785TS-S detection failed at 0x%02x.\n",
 195                                 address);
 196                         goto exit_free;
 197                 }
 198         }
 199
 200         if (kind <= 0) { /* identification */
 201                 u16 man_id;
 202                 u8 chip_id;
 203
 204                 man_id = (w83l785ts_read_value(new_client,
 205                          W83L785TS_REG_MAN_ID1, 0) << 8) +
 206                          w83l785ts_read_value(new_client,
 207                          W83L785TS_REG_MAN_ID2, 0);
 208                 chip_id = w83l785ts_read_value(new_client,
 209                           W83L785TS_REG_CHIP_ID, 0);
 210
 211                 if (man_id == 0x5CA3) { /* Winbond */
 212                         if (chip_id == 0x70) { /* W83L785TS-S */
 213                                 kind = w83l785ts;
 214                         }
 215                 }
 216
 217                 if (kind <= 0) { /* identification failed */
 218                         dev_info(&adapter->dev,
 219                                  "Unsupported chip (man_id=0x%04X, "
 220                                  "chip_id=0x%02X).\n", man_id, chip_id);
 221                         goto exit_free;
 222                 }
 223         }
 224
 225         /* We can fill in the remaining client fields. */
 226         strlcpy(new_client->name, "w83l785ts", I2C_NAME_SIZE);
 227         data->valid = 0;
 228         mutex_init(&data->update_lock);
 229
 230         /* Default values in case the first read fails (unlikely). */
 231         data->temp[1] = data->temp[0] = 0;
 232
 233         /* Tell the I2C layer a new client has arrived. */
 234         if ((err = i2c_attach_client(new_client)))
 235                 goto exit_free;
 236
 237         /*
 238          * Initialize the W83L785TS chip
 239          * Nothing yet, assume it is already started.
 240          */
 241
 242         err = device_create_file(&new_client->dev,
 243                                  &sensor_dev_attr_temp1_input.dev_attr);
 244         if (err)
 245                 goto exit_remove;
 246
 247         err = device_create_file(&new_client->dev,
 248                                  &sensor_dev_attr_temp1_max.dev_attr);
 249         if (err)
 250                 goto exit_remove;
 251
 252         /* Register sysfs hooks */
 253         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 254         if (IS_ERR(data->hwmon_dev)) {
 255                 err = PTR_ERR(data->hwmon_dev);
 256                 goto exit_remove;
 257         }
 258
 259         return 0;
 260
 261 exit_remove:
 262         device_remove_file(&new_client->dev,
 263                            &sensor_dev_attr_temp1_input.dev_attr);
 264         device_remove_file(&new_client->dev,
 265                            &sensor_dev_attr_temp1_max.dev_attr);
 266         i2c_detach_client(new_client);
 267 exit_free:
 268         kfree(data);
 269 exit:
 270         return err;
 271 }
 272
 273 static int w83l785ts_detach_client(struct i2c_client *client)
 274 {
 275         struct w83l785ts_data *data = i2c_get_clientdata(client);
 276         int err;
 277
 278         hwmon_device_unregister(data->hwmon_dev);
 279         device_remove_file(&client->dev,
 280                            &sensor_dev_attr_temp1_input.dev_attr);
 281         device_remove_file(&client->dev,
 282                            &sensor_dev_attr_temp1_max.dev_attr);
 283         if ((err = i2c_detach_client(client)))
 284                 return err;
 285
 286         kfree(data);
 287         return 0;
 288 }
 289
 290 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
 291 {
 292         int value, i;
 293
 294         /* Frequent read errors have been reported on Asus boards, so we
 295          * retry on read errors. If it still fails (unlikely), return the
 296          * default value requested by the caller. */
 297         for (i = 1; i <= MAX_RETRIES; i++) {
 298                 value = i2c_smbus_read_byte_data(client, reg);
 299                 if (value >= 0) {
 300                         dev_dbg(&client->dev, "Read 0x%02x from register "
 301                                 "0x%02x.\n", value, reg);
 302                         return value;
 303                 }
 304                 dev_dbg(&client->dev, "Read failed, will retry in %d.\n", i);
 305                 msleep(i);
 306         }
 307
 308         dev_err(&client->dev, "Couldn't read value from register 0x%02x. "
 309                 "Please report.\n", reg);
 310         return defval;
 311 }
 312
 313 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev)
 314 {
 315         struct i2c_client *client = to_i2c_client(dev);
 316         struct w83l785ts_data *data = i2c_get_clientdata(client);
 317
 318         mutex_lock(&data->update_lock);
 319
 320         if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) {
 321                 dev_dbg(&client->dev, "Updating w83l785ts data.\n");
 322                 data->temp[0] = w83l785ts_read_value(client,
 323                                 W83L785TS_REG_TEMP, data->temp[0]);
 324                 data->temp[1] = w83l785ts_read_value(client,
 325                                 W83L785TS_REG_TEMP_OVER, data->temp[1]);
 326
 327                 data->last_updated = jiffies;
 328                 data->valid = 1;
 329         }
 330
 331         mutex_unlock(&data->update_lock);
 332
 333         return data;
 334 }
 335
 336 static int __init sensors_w83l785ts_init(void)
 337 {
 338         return i2c_add_driver(&w83l785ts_driver);
 339 }
 340
 341 static void __exit sensors_w83l785ts_exit(void)
 342 {
 343         i2c_del_driver(&w83l785ts_driver);
 344 }
 345
 346 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 347 MODULE_DESCRIPTION("W83L785TS-S driver");
 348 MODULE_LICENSE("GPL");
 349
 350 module_init(sensors_w83l785ts_init);
 351 module_exit(sensors_w83l785ts_exit);