drivers/hwmon/jc42.c

   1 /*
   2  * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
   3  *
   4  * Copyright (c) 2010  Ericsson AB.
   5  *
   6  * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
   7  *
   8  * JC42.4 compliant temperature sensors are typically used on memory modules.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/i2c.h>
  30 #include <linux/hwmon.h>
  31 #include <linux/hwmon-sysfs.h>
  32 #include <linux/err.h>
  33 #include <linux/mutex.h>
  34
  35 /* Addresses to scan */
  36 static const unsigned short normal_i2c[] = {
  37         0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
  38
  39 /* JC42 registers. All registers are 16 bit. */
  40 #define JC42_REG_CAP            0x00
  41 #define JC42_REG_CONFIG         0x01
  42 #define JC42_REG_TEMP_UPPER     0x02
  43 #define JC42_REG_TEMP_LOWER     0x03
  44 #define JC42_REG_TEMP_CRITICAL  0x04
  45 #define JC42_REG_TEMP           0x05
  46 #define JC42_REG_MANID          0x06
  47 #define JC42_REG_DEVICEID       0x07
  48
  49 /* Status bits in temperature register */
  50 #define JC42_ALARM_CRIT_BIT     15
  51 #define JC42_ALARM_MAX_BIT      14
  52 #define JC42_ALARM_MIN_BIT      13
  53
  54 /* Configuration register defines */
  55 #define JC42_CFG_CRIT_ONLY      (1 << 2)
  56 #define JC42_CFG_TCRIT_LOCK     (1 << 6)
  57 #define JC42_CFG_EVENT_LOCK     (1 << 7)
  58 #define JC42_CFG_SHUTDOWN       (1 << 8)
  59 #define JC42_CFG_HYST_SHIFT     9
  60 #define JC42_CFG_HYST_MASK      (0x03 << 9)
  61
  62 /* Capabilities */
  63 #define JC42_CAP_RANGE          (1 << 2)
  64
  65 /* Manufacturer IDs */
  66 #define ADT_MANID               0x11d4  /* Analog Devices */
  67 #define ATMEL_MANID             0x001f  /* Atmel */
  68 #define ATMEL_MANID2            0x1114  /* Atmel */
  69 #define MAX_MANID               0x004d  /* Maxim */
  70 #define IDT_MANID               0x00b3  /* IDT */
  71 #define MCP_MANID               0x0054  /* Microchip */
  72 #define NXP_MANID               0x1131  /* NXP Semiconductors */
  73 #define ONS_MANID               0x1b09  /* ON Semiconductor */
  74 #define STM_MANID               0x104a  /* ST Microelectronics */
  75
  76 /* Supported chips */
  77
  78 /* Analog Devices */
  79 #define ADT7408_DEVID           0x0801
  80 #define ADT7408_DEVID_MASK      0xffff
  81
  82 /* Atmel */
  83 #define AT30TS00_DEVID          0x8201
  84 #define AT30TS00_DEVID_MASK     0xffff
  85
  86 #define AT30TSE004_DEVID        0x2200
  87 #define AT30TSE004_DEVID_MASK   0xffff
  88
  89 /* IDT */
  90 #define TS3000B3_DEVID          0x2903  /* Also matches TSE2002B3 */
  91 #define TS3000B3_DEVID_MASK     0xffff
  92
  93 #define TS3000GB2_DEVID         0x2912  /* Also matches TSE2002GB2 */
  94 #define TS3000GB2_DEVID_MASK    0xffff
  95
  96 /* Maxim */
  97 #define MAX6604_DEVID           0x3e00
  98 #define MAX6604_DEVID_MASK      0xffff
  99
 100 /* Microchip */
 101 #define MCP9804_DEVID           0x0200
 102 #define MCP9804_DEVID_MASK      0xfffc
 103
 104 #define MCP98242_DEVID          0x2000
 105 #define MCP98242_DEVID_MASK     0xfffc
 106
 107 #define MCP98243_DEVID          0x2100
 108 #define MCP98243_DEVID_MASK     0xfffc
 109
 110 #define MCP98244_DEVID          0x2200
 111 #define MCP98244_DEVID_MASK     0xfffc
 112
 113 #define MCP9843_DEVID           0x0000  /* Also matches mcp9805 */
 114 #define MCP9843_DEVID_MASK      0xfffe
 115
 116 /* NXP */
 117 #define SE97_DEVID              0xa200
 118 #define SE97_DEVID_MASK         0xfffc
 119
 120 #define SE98_DEVID              0xa100
 121 #define SE98_DEVID_MASK         0xfffc
 122
 123 /* ON Semiconductor */
 124 #define CAT6095_DEVID           0x0800  /* Also matches CAT34TS02 */
 125 #define CAT6095_DEVID_MASK      0xffe0
 126
 127 /* ST Microelectronics */
 128 #define STTS424_DEVID           0x0101
 129 #define STTS424_DEVID_MASK      0xffff
 130
 131 #define STTS424E_DEVID          0x0000
 132 #define STTS424E_DEVID_MASK     0xfffe
 133
 134 #define STTS2002_DEVID          0x0300
 135 #define STTS2002_DEVID_MASK     0xffff
 136
 137 #define STTS2004_DEVID          0x2201
 138 #define STTS2004_DEVID_MASK     0xffff
 139
 140 #define STTS3000_DEVID          0x0200
 141 #define STTS3000_DEVID_MASK     0xffff
 142
 143 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
 144
 145 struct jc42_chips {
 146         u16 manid;
 147         u16 devid;
 148         u16 devid_mask;
 149 };
 150
 151 static struct jc42_chips jc42_chips[] = {
 152         { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
 153         { ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
 154         { ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
 155         { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
 156         { IDT_MANID, TS3000GB2_DEVID, TS3000GB2_DEVID_MASK },
 157         { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
 158         { MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
 159         { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
 160         { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
 161         { MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
 162         { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
 163         { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
 164         { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
 165         { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
 166         { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
 167         { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
 168         { STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
 169         { STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
 170         { STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
 171 };
 172
 173 enum temp_index {
 174         t_input = 0,
 175         t_crit,
 176         t_min,
 177         t_max,
 178         t_num_temp
 179 };
 180
 181 static const u8 temp_regs[t_num_temp] = {
 182         [t_input] = JC42_REG_TEMP,
 183         [t_crit] = JC42_REG_TEMP_CRITICAL,
 184         [t_min] = JC42_REG_TEMP_LOWER,
 185         [t_max] = JC42_REG_TEMP_UPPER,
 186 };
 187
 188 /* Each client has this additional data */
 189 struct jc42_data {
 190         struct i2c_client *client;
 191         struct mutex    update_lock;    /* protect register access */
 192         bool            extended;       /* true if extended range supported */
 193         bool            valid;
 194         unsigned long   last_updated;   /* In jiffies */
 195         u16             orig_config;    /* original configuration */
 196         u16             config;         /* current configuration */
 197         u16             temp[t_num_temp];/* Temperatures */
 198 };
 199
 200 #define JC42_TEMP_MIN_EXTENDED  (-40000)
 201 #define JC42_TEMP_MIN           0
 202 #define JC42_TEMP_MAX           125000
 203
 204 static u16 jc42_temp_to_reg(long temp, bool extended)
 205 {
 206         int ntemp = clamp_val(temp,
 207                               extended ? JC42_TEMP_MIN_EXTENDED :
 208                               JC42_TEMP_MIN, JC42_TEMP_MAX);
 209
 210         /* convert from 0.001 to 0.0625 resolution */
 211         return (ntemp * 2 / 125) & 0x1fff;
 212 }
 213
 214 static int jc42_temp_from_reg(s16 reg)
 215 {
 216         reg = sign_extend32(reg, 12);
 217
 218         /* convert from 0.0625 to 0.001 resolution */
 219         return reg * 125 / 2;
 220 }
 221
 222 static struct jc42_data *jc42_update_device(struct device *dev)
 223 {
 224         struct jc42_data *data = dev_get_drvdata(dev);
 225         struct i2c_client *client = data->client;
 226         struct jc42_data *ret = data;
 227         int i, val;
 228
 229         mutex_lock(&data->update_lock);
 230
 231         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 232                 for (i = 0; i < t_num_temp; i++) {
 233                         val = i2c_smbus_read_word_swapped(client, temp_regs[i]);
 234                         if (val < 0) {
 235                                 ret = ERR_PTR(val);
 236                                 goto abort;
 237                         }
 238                         data->temp[i] = val;
 239                 }
 240                 data->last_updated = jiffies;
 241                 data->valid = true;
 242         }
 243 abort:
 244         mutex_unlock(&data->update_lock);
 245         return ret;
 246 }
 247
 248 /* sysfs functions */
 249
 250 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 251                          char *buf)
 252 {
 253         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 254         struct jc42_data *data = jc42_update_device(dev);
 255         if (IS_ERR(data))
 256                 return PTR_ERR(data);
 257         return sprintf(buf, "%d\n",
 258                        jc42_temp_from_reg(data->temp[attr->index]));
 259 }
 260
 261 static ssize_t show_temp_hyst(struct device *dev,
 262                               struct device_attribute *devattr, char *buf)
 263 {
 264         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 265         struct jc42_data *data = jc42_update_device(dev);
 266         int temp, hyst;
 267
 268         if (IS_ERR(data))
 269                 return PTR_ERR(data);
 270
 271         temp = jc42_temp_from_reg(data->temp[attr->index]);
 272         hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
 273                                >> JC42_CFG_HYST_SHIFT];
 274         return sprintf(buf, "%d\n", temp - hyst);
 275 }
 276
 277 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 278                         const char *buf, size_t count)
 279 {
 280         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 281         struct jc42_data *data = dev_get_drvdata(dev);
 282         int err, ret = count;
 283         int nr = attr->index;
 284         long val;
 285
 286         if (kstrtol(buf, 10, &val) < 0)
 287                 return -EINVAL;
 288         mutex_lock(&data->update_lock);
 289         data->temp[nr] = jc42_temp_to_reg(val, data->extended);
 290         err = i2c_smbus_write_word_swapped(data->client, temp_regs[nr],
 291                                            data->temp[nr]);
 292         if (err < 0)
 293                 ret = err;
 294         mutex_unlock(&data->update_lock);
 295         return ret;
 296 }
 297
 298 /*
 299  * JC42.4 compliant chips only support four hysteresis values.
 300  * Pick best choice and go from there.
 301  */
 302 static ssize_t set_temp_crit_hyst(struct device *dev,
 303                                   struct device_attribute *attr,
 304                                   const char *buf, size_t count)
 305 {
 306         struct jc42_data *data = dev_get_drvdata(dev);
 307         long val;
 308         int diff, hyst;
 309         int err;
 310         int ret = count;
 311
 312         if (kstrtol(buf, 10, &val) < 0)
 313                 return -EINVAL;
 314
 315         val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED :
 316                               JC42_TEMP_MIN) - 6000, JC42_TEMP_MAX);
 317         diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
 318
 319         hyst = 0;
 320         if (diff > 0) {
 321                 if (diff < 2250)
 322                         hyst = 1;       /* 1.5 degrees C */
 323                 else if (diff < 4500)
 324                         hyst = 2;       /* 3.0 degrees C */
 325                 else
 326                         hyst = 3;       /* 6.0 degrees C */
 327         }
 328
 329         mutex_lock(&data->update_lock);
 330         data->config = (data->config & ~JC42_CFG_HYST_MASK)
 331           | (hyst << JC42_CFG_HYST_SHIFT);
 332         err = i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 333                                            data->config);
 334         if (err < 0)
 335                 ret = err;
 336         mutex_unlock(&data->update_lock);
 337         return ret;
 338 }
 339
 340 static ssize_t show_alarm(struct device *dev,
 341                           struct device_attribute *attr, char *buf)
 342 {
 343         u16 bit = to_sensor_dev_attr(attr)->index;
 344         struct jc42_data *data = jc42_update_device(dev);
 345         u16 val;
 346
 347         if (IS_ERR(data))
 348                 return PTR_ERR(data);
 349
 350         val = data->temp[t_input];
 351         if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
 352                 val = 0;
 353         return sprintf(buf, "%u\n", (val >> bit) & 1);
 354 }
 355
 356 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input);
 357 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, set_temp, t_crit);
 358 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp, set_temp, t_min);
 359 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, set_temp, t_max);
 360
 361 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO, show_temp_hyst,
 362                           set_temp_crit_hyst, t_crit);
 363 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max);
 364
 365 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 366                           JC42_ALARM_CRIT_BIT);
 367 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 368                           JC42_ALARM_MIN_BIT);
 369 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 370                           JC42_ALARM_MAX_BIT);
 371
 372 static struct attribute *jc42_attributes[] = {
 373         &sensor_dev_attr_temp1_input.dev_attr.attr,
 374         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 375         &sensor_dev_attr_temp1_min.dev_attr.attr,
 376         &sensor_dev_attr_temp1_max.dev_attr.attr,
 377         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 378         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 379         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 380         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 381         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 382         NULL
 383 };
 384
 385 static umode_t jc42_attribute_mode(struct kobject *kobj,
 386                                   struct attribute *attr, int index)
 387 {
 388         struct device *dev = container_of(kobj, struct device, kobj);
 389         struct jc42_data *data = dev_get_drvdata(dev);
 390         unsigned int config = data->config;
 391         bool readonly;
 392
 393         if (attr == &sensor_dev_attr_temp1_crit.dev_attr.attr)
 394                 readonly = config & JC42_CFG_TCRIT_LOCK;
 395         else if (attr == &sensor_dev_attr_temp1_min.dev_attr.attr ||
 396                  attr == &sensor_dev_attr_temp1_max.dev_attr.attr)
 397                 readonly = config & JC42_CFG_EVENT_LOCK;
 398         else if (attr == &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr)
 399                 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
 400         else
 401                 readonly = true;
 402
 403         return S_IRUGO | (readonly ? 0 : S_IWUSR);
 404 }
 405
 406 static const struct attribute_group jc42_group = {
 407         .attrs = jc42_attributes,
 408         .is_visible = jc42_attribute_mode,
 409 };
 410 __ATTRIBUTE_GROUPS(jc42);
 411
 412 /* Return 0 if detection is successful, -ENODEV otherwise */
 413 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
 414 {
 415         struct i2c_adapter *adapter = client->adapter;
 416         int i, config, cap, manid, devid;
 417
 418         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 419                                      I2C_FUNC_SMBUS_WORD_DATA))
 420                 return -ENODEV;
 421
 422         cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
 423         config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
 424         manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
 425         devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
 426
 427         if (cap < 0 || config < 0 || manid < 0 || devid < 0)
 428                 return -ENODEV;
 429
 430         if ((cap & 0xff00) || (config & 0xf800))
 431                 return -ENODEV;
 432
 433         for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
 434                 struct jc42_chips *chip = &jc42_chips[i];
 435                 if (manid == chip->manid &&
 436                     (devid & chip->devid_mask) == chip->devid) {
 437                         strlcpy(info->type, "jc42", I2C_NAME_SIZE);
 438                         return 0;
 439                 }
 440         }
 441         return -ENODEV;
 442 }
 443
 444 static int jc42_probe(struct i2c_client *client, const struct i2c_device_id *id)
 445 {
 446         struct device *dev = &client->dev;
 447         struct device *hwmon_dev;
 448         struct jc42_data *data;
 449         int config, cap;
 450
 451         data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
 452         if (!data)
 453                 return -ENOMEM;
 454
 455         data->client = client;
 456         i2c_set_clientdata(client, data);
 457         mutex_init(&data->update_lock);
 458
 459         cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
 460         if (cap < 0)
 461                 return cap;
 462
 463         data->extended = !!(cap & JC42_CAP_RANGE);
 464
 465         config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
 466         if (config < 0)
 467                 return config;
 468
 469         data->orig_config = config;
 470         if (config & JC42_CFG_SHUTDOWN) {
 471                 config &= ~JC42_CFG_SHUTDOWN;
 472                 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
 473         }
 474         data->config = config;
 475
 476         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 477                                                            data,
 478                                                            jc42_groups);
 479         return PTR_ERR_OR_ZERO(hwmon_dev);
 480 }
 481
 482 static int jc42_remove(struct i2c_client *client)
 483 {
 484         struct jc42_data *data = i2c_get_clientdata(client);
 485
 486         /* Restore original configuration except hysteresis */
 487         if ((data->config & ~JC42_CFG_HYST_MASK) !=
 488             (data->orig_config & ~JC42_CFG_HYST_MASK)) {
 489                 int config;
 490
 491                 config = (data->orig_config & ~JC42_CFG_HYST_MASK)
 492                   | (data->config & JC42_CFG_HYST_MASK);
 493                 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
 494         }
 495         return 0;
 496 }
 497
 498 #ifdef CONFIG_PM
 499
 500 static int jc42_suspend(struct device *dev)
 501 {
 502         struct jc42_data *data = dev_get_drvdata(dev);
 503
 504         data->config |= JC42_CFG_SHUTDOWN;
 505         i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 506                                      data->config);
 507         return 0;
 508 }
 509
 510 static int jc42_resume(struct device *dev)
 511 {
 512         struct jc42_data *data = dev_get_drvdata(dev);
 513
 514         data->config &= ~JC42_CFG_SHUTDOWN;
 515         i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 516                                      data->config);
 517         return 0;
 518 }
 519
 520 static const struct dev_pm_ops jc42_dev_pm_ops = {
 521         .suspend = jc42_suspend,
 522         .resume = jc42_resume,
 523 };
 524
 525 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
 526 #else
 527 #define JC42_DEV_PM_OPS NULL
 528 #endif /* CONFIG_PM */
 529
 530 static const struct i2c_device_id jc42_id[] = {
 531         { "jc42", 0 },
 532         { }
 533 };
 534 MODULE_DEVICE_TABLE(i2c, jc42_id);
 535
 536 static struct i2c_driver jc42_driver = {
 537         .class          = I2C_CLASS_SPD,
 538         .driver = {
 539                 .name   = "jc42",
 540                 .pm = JC42_DEV_PM_OPS,
 541         },
 542         .probe          = jc42_probe,
 543         .remove         = jc42_remove,
 544         .id_table       = jc42_id,
 545         .detect         = jc42_detect,
 546         .address_list   = normal_i2c,
 547 };
 548
 549 module_i2c_driver(jc42_driver);
 550
 551 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
 552 MODULE_DESCRIPTION("JC42 driver");
 553 MODULE_LICENSE("GPL");