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 TSE2004_DEVID           0x2200
  91 #define TSE2004_DEVID_MASK      0xff00
  92
  93 #define TS3000_DEVID            0x2900  /* Also matches TSE2002 */
  94 #define TS3000_DEVID_MASK       0xff00
  95
  96 #define TS3001_DEVID            0x3000
  97 #define TS3001_DEVID_MASK       0xff00
  98
  99 /* Maxim */
 100 #define MAX6604_DEVID           0x3e00
 101 #define MAX6604_DEVID_MASK      0xffff
 102
 103 /* Microchip */
 104 #define MCP9804_DEVID           0x0200
 105 #define MCP9804_DEVID_MASK      0xfffc
 106
 107 #define MCP98242_DEVID          0x2000
 108 #define MCP98242_DEVID_MASK     0xfffc
 109
 110 #define MCP98243_DEVID          0x2100
 111 #define MCP98243_DEVID_MASK     0xfffc
 112
 113 #define MCP98244_DEVID          0x2200
 114 #define MCP98244_DEVID_MASK     0xfffc
 115
 116 #define MCP9843_DEVID           0x0000  /* Also matches mcp9805 */
 117 #define MCP9843_DEVID_MASK      0xfffe
 118
 119 /* NXP */
 120 #define SE97_DEVID              0xa200
 121 #define SE97_DEVID_MASK         0xfffc
 122
 123 #define SE98_DEVID              0xa100
 124 #define SE98_DEVID_MASK         0xfffc
 125
 126 /* ON Semiconductor */
 127 #define CAT6095_DEVID           0x0800  /* Also matches CAT34TS02 */
 128 #define CAT6095_DEVID_MASK      0xffe0
 129
 130 /* ST Microelectronics */
 131 #define STTS424_DEVID           0x0101
 132 #define STTS424_DEVID_MASK      0xffff
 133
 134 #define STTS424E_DEVID          0x0000
 135 #define STTS424E_DEVID_MASK     0xfffe
 136
 137 #define STTS2002_DEVID          0x0300
 138 #define STTS2002_DEVID_MASK     0xffff
 139
 140 #define STTS2004_DEVID          0x2201
 141 #define STTS2004_DEVID_MASK     0xffff
 142
 143 #define STTS3000_DEVID          0x0200
 144 #define STTS3000_DEVID_MASK     0xffff
 145
 146 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
 147
 148 struct jc42_chips {
 149         u16 manid;
 150         u16 devid;
 151         u16 devid_mask;
 152 };
 153
 154 static struct jc42_chips jc42_chips[] = {
 155         { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
 156         { ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
 157         { ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
 158         { IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
 159         { IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
 160         { IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
 161         { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
 162         { MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
 163         { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
 164         { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
 165         { MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
 166         { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
 167         { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
 168         { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
 169         { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
 170         { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
 171         { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
 172         { STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
 173         { STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
 174         { STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
 175 };
 176
 177 enum temp_index {
 178         t_input = 0,
 179         t_crit,
 180         t_min,
 181         t_max,
 182         t_num_temp
 183 };
 184
 185 static const u8 temp_regs[t_num_temp] = {
 186         [t_input] = JC42_REG_TEMP,
 187         [t_crit] = JC42_REG_TEMP_CRITICAL,
 188         [t_min] = JC42_REG_TEMP_LOWER,
 189         [t_max] = JC42_REG_TEMP_UPPER,
 190 };
 191
 192 /* Each client has this additional data */
 193 struct jc42_data {
 194         struct i2c_client *client;
 195         struct mutex    update_lock;    /* protect register access */
 196         bool            extended;       /* true if extended range supported */
 197         bool            valid;
 198         unsigned long   last_updated;   /* In jiffies */
 199         u16             orig_config;    /* original configuration */
 200         u16             config;         /* current configuration */
 201         u16             temp[t_num_temp];/* Temperatures */
 202 };
 203
 204 #define JC42_TEMP_MIN_EXTENDED  (-40000)
 205 #define JC42_TEMP_MIN           0
 206 #define JC42_TEMP_MAX           125000
 207
 208 static u16 jc42_temp_to_reg(long temp, bool extended)
 209 {
 210         int ntemp = clamp_val(temp,
 211                               extended ? JC42_TEMP_MIN_EXTENDED :
 212                               JC42_TEMP_MIN, JC42_TEMP_MAX);
 213
 214         /* convert from 0.001 to 0.0625 resolution */
 215         return (ntemp * 2 / 125) & 0x1fff;
 216 }
 217
 218 static int jc42_temp_from_reg(s16 reg)
 219 {
 220         reg = sign_extend32(reg, 12);
 221
 222         /* convert from 0.0625 to 0.001 resolution */
 223         return reg * 125 / 2;
 224 }
 225
 226 static struct jc42_data *jc42_update_device(struct device *dev)
 227 {
 228         struct jc42_data *data = dev_get_drvdata(dev);
 229         struct i2c_client *client = data->client;
 230         struct jc42_data *ret = data;
 231         int i, val;
 232
 233         mutex_lock(&data->update_lock);
 234
 235         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 236                 for (i = 0; i < t_num_temp; i++) {
 237                         val = i2c_smbus_read_word_swapped(client, temp_regs[i]);
 238                         if (val < 0) {
 239                                 ret = ERR_PTR(val);
 240                                 goto abort;
 241                         }
 242                         data->temp[i] = val;
 243                 }
 244                 data->last_updated = jiffies;
 245                 data->valid = true;
 246         }
 247 abort:
 248         mutex_unlock(&data->update_lock);
 249         return ret;
 250 }
 251
 252 /* sysfs functions */
 253
 254 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 255                          char *buf)
 256 {
 257         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 258         struct jc42_data *data = jc42_update_device(dev);
 259         if (IS_ERR(data))
 260                 return PTR_ERR(data);
 261         return sprintf(buf, "%d\n",
 262                        jc42_temp_from_reg(data->temp[attr->index]));
 263 }
 264
 265 static ssize_t show_temp_hyst(struct device *dev,
 266                               struct device_attribute *devattr, char *buf)
 267 {
 268         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 269         struct jc42_data *data = jc42_update_device(dev);
 270         int temp, hyst;
 271
 272         if (IS_ERR(data))
 273                 return PTR_ERR(data);
 274
 275         temp = jc42_temp_from_reg(data->temp[attr->index]);
 276         hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
 277                                >> JC42_CFG_HYST_SHIFT];
 278         return sprintf(buf, "%d\n", temp - hyst);
 279 }
 280
 281 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 282                         const char *buf, size_t count)
 283 {
 284         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 285         struct jc42_data *data = dev_get_drvdata(dev);
 286         int err, ret = count;
 287         int nr = attr->index;
 288         long val;
 289
 290         if (kstrtol(buf, 10, &val) < 0)
 291                 return -EINVAL;
 292         mutex_lock(&data->update_lock);
 293         data->temp[nr] = jc42_temp_to_reg(val, data->extended);
 294         err = i2c_smbus_write_word_swapped(data->client, temp_regs[nr],
 295                                            data->temp[nr]);
 296         if (err < 0)
 297                 ret = err;
 298         mutex_unlock(&data->update_lock);
 299         return ret;
 300 }
 301
 302 /*
 303  * JC42.4 compliant chips only support four hysteresis values.
 304  * Pick best choice and go from there.
 305  */
 306 static ssize_t set_temp_crit_hyst(struct device *dev,
 307                                   struct device_attribute *attr,
 308                                   const char *buf, size_t count)
 309 {
 310         struct jc42_data *data = dev_get_drvdata(dev);
 311         long val;
 312         int diff, hyst;
 313         int err;
 314         int ret = count;
 315
 316         if (kstrtol(buf, 10, &val) < 0)
 317                 return -EINVAL;
 318
 319         val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED :
 320                               JC42_TEMP_MIN) - 6000, JC42_TEMP_MAX);
 321         diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
 322
 323         hyst = 0;
 324         if (diff > 0) {
 325                 if (diff < 2250)
 326                         hyst = 1;       /* 1.5 degrees C */
 327                 else if (diff < 4500)
 328                         hyst = 2;       /* 3.0 degrees C */
 329                 else
 330                         hyst = 3;       /* 6.0 degrees C */
 331         }
 332
 333         mutex_lock(&data->update_lock);
 334         data->config = (data->config & ~JC42_CFG_HYST_MASK)
 335           | (hyst << JC42_CFG_HYST_SHIFT);
 336         err = i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 337                                            data->config);
 338         if (err < 0)
 339                 ret = err;
 340         mutex_unlock(&data->update_lock);
 341         return ret;
 342 }
 343
 344 static ssize_t show_alarm(struct device *dev,
 345                           struct device_attribute *attr, char *buf)
 346 {
 347         u16 bit = to_sensor_dev_attr(attr)->index;
 348         struct jc42_data *data = jc42_update_device(dev);
 349         u16 val;
 350
 351         if (IS_ERR(data))
 352                 return PTR_ERR(data);
 353
 354         val = data->temp[t_input];
 355         if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
 356                 val = 0;
 357         return sprintf(buf, "%u\n", (val >> bit) & 1);
 358 }
 359
 360 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input);
 361 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, set_temp, t_crit);
 362 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp, set_temp, t_min);
 363 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, set_temp, t_max);
 364
 365 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO, show_temp_hyst,
 366                           set_temp_crit_hyst, t_crit);
 367 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max);
 368
 369 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 370                           JC42_ALARM_CRIT_BIT);
 371 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 372                           JC42_ALARM_MIN_BIT);
 373 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 374                           JC42_ALARM_MAX_BIT);
 375
 376 static struct attribute *jc42_attributes[] = {
 377         &sensor_dev_attr_temp1_input.dev_attr.attr,
 378         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 379         &sensor_dev_attr_temp1_min.dev_attr.attr,
 380         &sensor_dev_attr_temp1_max.dev_attr.attr,
 381         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 382         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 383         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 384         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 385         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 386         NULL
 387 };
 388
 389 static umode_t jc42_attribute_mode(struct kobject *kobj,
 390                                   struct attribute *attr, int index)
 391 {
 392         struct device *dev = container_of(kobj, struct device, kobj);
 393         struct jc42_data *data = dev_get_drvdata(dev);
 394         unsigned int config = data->config;
 395         bool readonly;
 396
 397         if (attr == &sensor_dev_attr_temp1_crit.dev_attr.attr)
 398                 readonly = config & JC42_CFG_TCRIT_LOCK;
 399         else if (attr == &sensor_dev_attr_temp1_min.dev_attr.attr ||
 400                  attr == &sensor_dev_attr_temp1_max.dev_attr.attr)
 401                 readonly = config & JC42_CFG_EVENT_LOCK;
 402         else if (attr == &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr)
 403                 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
 404         else
 405                 readonly = true;
 406
 407         return S_IRUGO | (readonly ? 0 : S_IWUSR);
 408 }
 409
 410 static const struct attribute_group jc42_group = {
 411         .attrs = jc42_attributes,
 412         .is_visible = jc42_attribute_mode,
 413 };
 414 __ATTRIBUTE_GROUPS(jc42);
 415
 416 /* Return 0 if detection is successful, -ENODEV otherwise */
 417 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
 418 {
 419         struct i2c_adapter *adapter = client->adapter;
 420         int i, config, cap, manid, devid;
 421
 422         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 423                                      I2C_FUNC_SMBUS_WORD_DATA))
 424                 return -ENODEV;
 425
 426         cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
 427         config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
 428         manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
 429         devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
 430
 431         if (cap < 0 || config < 0 || manid < 0 || devid < 0)
 432                 return -ENODEV;
 433
 434         if ((cap & 0xff00) || (config & 0xf800))
 435                 return -ENODEV;
 436
 437         for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
 438                 struct jc42_chips *chip = &jc42_chips[i];
 439                 if (manid == chip->manid &&
 440                     (devid & chip->devid_mask) == chip->devid) {
 441                         strlcpy(info->type, "jc42", I2C_NAME_SIZE);
 442                         return 0;
 443                 }
 444         }
 445         return -ENODEV;
 446 }
 447
 448 static int jc42_probe(struct i2c_client *client, const struct i2c_device_id *id)
 449 {
 450         struct device *dev = &client->dev;
 451         struct device *hwmon_dev;
 452         struct jc42_data *data;
 453         int config, cap;
 454
 455         data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
 456         if (!data)
 457                 return -ENOMEM;
 458
 459         data->client = client;
 460         i2c_set_clientdata(client, data);
 461         mutex_init(&data->update_lock);
 462
 463         cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
 464         if (cap < 0)
 465                 return cap;
 466
 467         data->extended = !!(cap & JC42_CAP_RANGE);
 468
 469         config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
 470         if (config < 0)
 471                 return config;
 472
 473         data->orig_config = config;
 474         if (config & JC42_CFG_SHUTDOWN) {
 475                 config &= ~JC42_CFG_SHUTDOWN;
 476                 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
 477         }
 478         data->config = config;
 479
 480         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 481                                                            data,
 482                                                            jc42_groups);
 483         return PTR_ERR_OR_ZERO(hwmon_dev);
 484 }
 485
 486 static int jc42_remove(struct i2c_client *client)
 487 {
 488         struct jc42_data *data = i2c_get_clientdata(client);
 489
 490         /* Restore original configuration except hysteresis */
 491         if ((data->config & ~JC42_CFG_HYST_MASK) !=
 492             (data->orig_config & ~JC42_CFG_HYST_MASK)) {
 493                 int config;
 494
 495                 config = (data->orig_config & ~JC42_CFG_HYST_MASK)
 496                   | (data->config & JC42_CFG_HYST_MASK);
 497                 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
 498         }
 499         return 0;
 500 }
 501
 502 #ifdef CONFIG_PM
 503
 504 static int jc42_suspend(struct device *dev)
 505 {
 506         struct jc42_data *data = dev_get_drvdata(dev);
 507
 508         data->config |= JC42_CFG_SHUTDOWN;
 509         i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 510                                      data->config);
 511         return 0;
 512 }
 513
 514 static int jc42_resume(struct device *dev)
 515 {
 516         struct jc42_data *data = dev_get_drvdata(dev);
 517
 518         data->config &= ~JC42_CFG_SHUTDOWN;
 519         i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 520                                      data->config);
 521         return 0;
 522 }
 523
 524 static const struct dev_pm_ops jc42_dev_pm_ops = {
 525         .suspend = jc42_suspend,
 526         .resume = jc42_resume,
 527 };
 528
 529 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
 530 #else
 531 #define JC42_DEV_PM_OPS NULL
 532 #endif /* CONFIG_PM */
 533
 534 static const struct i2c_device_id jc42_id[] = {
 535         { "jc42", 0 },
 536         { }
 537 };
 538 MODULE_DEVICE_TABLE(i2c, jc42_id);
 539
 540 static struct i2c_driver jc42_driver = {
 541         .class          = I2C_CLASS_SPD,
 542         .driver = {
 543                 .name   = "jc42",
 544                 .pm = JC42_DEV_PM_OPS,
 545         },
 546         .probe          = jc42_probe,
 547         .remove         = jc42_remove,
 548         .id_table       = jc42_id,
 549         .detect         = jc42_detect,
 550         .address_list   = normal_i2c,
 551 };
 552
 553 module_i2c_driver(jc42_driver);
 554
 555 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
 556 MODULE_DESCRIPTION("JC42 driver");
 557 MODULE_LICENSE("GPL");