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(int 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 &= 0x1fff;
 217
 218         /* sign extend register */
 219         if (reg & 0x1000)
 220                 reg |= 0xf000;
 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         unsigned long val;
 312         int diff, hyst;
 313         int err;
 314         int ret = count;
 315
 316         if (kstrtoul(buf, 10, &val) < 0)
 317                 return -EINVAL;
 318
 319         diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
 320         hyst = 0;
 321         if (diff > 0) {
 322                 if (diff < 2250)
 323                         hyst = 1;       /* 1.5 degrees C */
 324                 else if (diff < 4500)
 325                         hyst = 2;       /* 3.0 degrees C */
 326                 else
 327                         hyst = 3;       /* 6.0 degrees C */
 328         }
 329
 330         mutex_lock(&data->update_lock);
 331         data->config = (data->config & ~JC42_CFG_HYST_MASK)
 332           | (hyst << JC42_CFG_HYST_SHIFT);
 333         err = i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 334                                            data->config);
 335         if (err < 0)
 336                 ret = err;
 337         mutex_unlock(&data->update_lock);
 338         return ret;
 339 }
 340
 341 static ssize_t show_alarm(struct device *dev,
 342                           struct device_attribute *attr, char *buf)
 343 {
 344         u16 bit = to_sensor_dev_attr(attr)->index;
 345         struct jc42_data *data = jc42_update_device(dev);
 346         u16 val;
 347
 348         if (IS_ERR(data))
 349                 return PTR_ERR(data);
 350
 351         val = data->temp[t_input];
 352         if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
 353                 val = 0;
 354         return sprintf(buf, "%u\n", (val >> bit) & 1);
 355 }
 356
 357 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input);
 358 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, set_temp, t_crit);
 359 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp, set_temp, t_min);
 360 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, set_temp, t_max);
 361
 362 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO, show_temp_hyst,
 363                           set_temp_crit_hyst, t_crit);
 364 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max);
 365
 366 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 367                           JC42_ALARM_CRIT_BIT);
 368 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 369                           JC42_ALARM_MIN_BIT);
 370 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 371                           JC42_ALARM_MAX_BIT);
 372
 373 static struct attribute *jc42_attributes[] = {
 374         &sensor_dev_attr_temp1_input.dev_attr.attr,
 375         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 376         &sensor_dev_attr_temp1_min.dev_attr.attr,
 377         &sensor_dev_attr_temp1_max.dev_attr.attr,
 378         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 379         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 380         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 381         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 382         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 383         NULL
 384 };
 385
 386 static umode_t jc42_attribute_mode(struct kobject *kobj,
 387                                   struct attribute *attr, int index)
 388 {
 389         struct device *dev = container_of(kobj, struct device, kobj);
 390         struct jc42_data *data = dev_get_drvdata(dev);
 391         unsigned int config = data->config;
 392         bool readonly;
 393
 394         if (attr == &sensor_dev_attr_temp1_crit.dev_attr.attr)
 395                 readonly = config & JC42_CFG_TCRIT_LOCK;
 396         else if (attr == &sensor_dev_attr_temp1_min.dev_attr.attr ||
 397                  attr == &sensor_dev_attr_temp1_max.dev_attr.attr)
 398                 readonly = config & JC42_CFG_EVENT_LOCK;
 399         else if (attr == &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr)
 400                 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
 401         else
 402                 readonly = true;
 403
 404         return S_IRUGO | (readonly ? 0 : S_IWUSR);
 405 }
 406
 407 static const struct attribute_group jc42_group = {
 408         .attrs = jc42_attributes,
 409         .is_visible = jc42_attribute_mode,
 410 };
 411 __ATTRIBUTE_GROUPS(jc42);
 412
 413 /* Return 0 if detection is successful, -ENODEV otherwise */
 414 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
 415 {
 416         struct i2c_adapter *adapter = client->adapter;
 417         int i, config, cap, manid, devid;
 418
 419         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 420                                      I2C_FUNC_SMBUS_WORD_DATA))
 421                 return -ENODEV;
 422
 423         cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
 424         config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
 425         manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
 426         devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
 427
 428         if (cap < 0 || config < 0 || manid < 0 || devid < 0)
 429                 return -ENODEV;
 430
 431         if ((cap & 0xff00) || (config & 0xf800))
 432                 return -ENODEV;
 433
 434         for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
 435                 struct jc42_chips *chip = &jc42_chips[i];
 436                 if (manid == chip->manid &&
 437                     (devid & chip->devid_mask) == chip->devid) {
 438                         strlcpy(info->type, "jc42", I2C_NAME_SIZE);
 439                         return 0;
 440                 }
 441         }
 442         return -ENODEV;
 443 }
 444
 445 static int jc42_probe(struct i2c_client *client, const struct i2c_device_id *id)
 446 {
 447         struct device *dev = &client->dev;
 448         struct device *hwmon_dev;
 449         struct jc42_data *data;
 450         int config, cap;
 451
 452         data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
 453         if (!data)
 454                 return -ENOMEM;
 455
 456         data->client = client;
 457         i2c_set_clientdata(client, data);
 458         mutex_init(&data->update_lock);
 459
 460         cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
 461         if (cap < 0)
 462                 return cap;
 463
 464         data->extended = !!(cap & JC42_CAP_RANGE);
 465
 466         config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
 467         if (config < 0)
 468                 return config;
 469
 470         data->orig_config = config;
 471         if (config & JC42_CFG_SHUTDOWN) {
 472                 config &= ~JC42_CFG_SHUTDOWN;
 473                 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
 474         }
 475         data->config = config;
 476
 477         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 478                                                            data,
 479                                                            jc42_groups);
 480         return PTR_ERR_OR_ZERO(hwmon_dev);
 481 }
 482
 483 static int jc42_remove(struct i2c_client *client)
 484 {
 485         struct jc42_data *data = i2c_get_clientdata(client);
 486
 487         /* Restore original configuration except hysteresis */
 488         if ((data->config & ~JC42_CFG_HYST_MASK) !=
 489             (data->orig_config & ~JC42_CFG_HYST_MASK)) {
 490                 int config;
 491
 492                 config = (data->orig_config & ~JC42_CFG_HYST_MASK)
 493                   | (data->config & JC42_CFG_HYST_MASK);
 494                 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
 495         }
 496         return 0;
 497 }
 498
 499 #ifdef CONFIG_PM
 500
 501 static int jc42_suspend(struct device *dev)
 502 {
 503         struct jc42_data *data = dev_get_drvdata(dev);
 504
 505         data->config |= JC42_CFG_SHUTDOWN;
 506         i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 507                                      data->config);
 508         return 0;
 509 }
 510
 511 static int jc42_resume(struct device *dev)
 512 {
 513         struct jc42_data *data = dev_get_drvdata(dev);
 514
 515         data->config &= ~JC42_CFG_SHUTDOWN;
 516         i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
 517                                      data->config);
 518         return 0;
 519 }
 520
 521 static const struct dev_pm_ops jc42_dev_pm_ops = {
 522         .suspend = jc42_suspend,
 523         .resume = jc42_resume,
 524 };
 525
 526 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
 527 #else
 528 #define JC42_DEV_PM_OPS NULL
 529 #endif /* CONFIG_PM */
 530
 531 static const struct i2c_device_id jc42_id[] = {
 532         { "jc42", 0 },
 533         { }
 534 };
 535 MODULE_DEVICE_TABLE(i2c, jc42_id);
 536
 537 static struct i2c_driver jc42_driver = {
 538         .class          = I2C_CLASS_SPD,
 539         .driver = {
 540                 .name   = "jc42",
 541                 .pm = JC42_DEV_PM_OPS,
 542         },
 543         .probe          = jc42_probe,
 544         .remove         = jc42_remove,
 545         .id_table       = jc42_id,
 546         .detect         = jc42_detect,
 547         .address_list   = normal_i2c,
 548 };
 549
 550 module_i2c_driver(jc42_driver);
 551
 552 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
 553 MODULE_DESCRIPTION("JC42 driver");
 554 MODULE_LICENSE("GPL");