1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors 4 * 5 * Copyright (c) 2010 Ericsson AB. 6 * 7 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>. 8 * 9 * JC42.4 compliant temperature sensors are typically used on memory modules. 10 */ 11 12 #include <linux/bitops.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/slab.h> 16 #include <linux/jiffies.h> 17 #include <linux/i2c.h> 18 #include <linux/hwmon.h> 19 #include <linux/err.h> 20 #include <linux/mutex.h> 21 #include <linux/of.h> 22 23 /* Addresses to scan */ 24 static const unsigned short normal_i2c[] = { 25 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END }; 26 27 /* JC42 registers. All registers are 16 bit. */ 28 #define JC42_REG_CAP 0x00 29 #define JC42_REG_CONFIG 0x01 30 #define JC42_REG_TEMP_UPPER 0x02 31 #define JC42_REG_TEMP_LOWER 0x03 32 #define JC42_REG_TEMP_CRITICAL 0x04 33 #define JC42_REG_TEMP 0x05 34 #define JC42_REG_MANID 0x06 35 #define JC42_REG_DEVICEID 0x07 36 #define JC42_REG_SMBUS 0x22 /* NXP and Atmel, possibly others? */ 37 38 /* Status bits in temperature register */ 39 #define JC42_ALARM_CRIT_BIT 15 40 #define JC42_ALARM_MAX_BIT 14 41 #define JC42_ALARM_MIN_BIT 13 42 43 /* Configuration register defines */ 44 #define JC42_CFG_CRIT_ONLY (1 << 2) 45 #define JC42_CFG_TCRIT_LOCK (1 << 6) 46 #define JC42_CFG_EVENT_LOCK (1 << 7) 47 #define JC42_CFG_SHUTDOWN (1 << 8) 48 #define JC42_CFG_HYST_SHIFT 9 49 #define JC42_CFG_HYST_MASK (0x03 << 9) 50 51 /* Capabilities */ 52 #define JC42_CAP_RANGE (1 << 2) 53 54 /* Manufacturer IDs */ 55 #define ADT_MANID 0x11d4 /* Analog Devices */ 56 #define ATMEL_MANID 0x001f /* Atmel */ 57 #define ATMEL_MANID2 0x1114 /* Atmel */ 58 #define MAX_MANID 0x004d /* Maxim */ 59 #define IDT_MANID 0x00b3 /* IDT */ 60 #define MCP_MANID 0x0054 /* Microchip */ 61 #define NXP_MANID 0x1131 /* NXP Semiconductors */ 62 #define ONS_MANID 0x1b09 /* ON Semiconductor */ 63 #define STM_MANID 0x104a /* ST Microelectronics */ 64 #define GT_MANID 0x1c68 /* Giantec */ 65 #define GT_MANID2 0x132d /* Giantec, 2nd mfg ID */ 66 #define SI_MANID 0x1c85 /* Seiko Instruments */ 67 68 /* SMBUS register */ 69 #define SMBUS_STMOUT BIT(7) /* SMBus time-out, active low */ 70 71 /* Supported chips */ 72 73 /* Analog Devices */ 74 #define ADT7408_DEVID 0x0801 75 #define ADT7408_DEVID_MASK 0xffff 76 77 /* Atmel */ 78 #define AT30TS00_DEVID 0x8201 79 #define AT30TS00_DEVID_MASK 0xffff 80 81 #define AT30TSE004_DEVID 0x2200 82 #define AT30TSE004_DEVID_MASK 0xffff 83 84 /* Giantec */ 85 #define GT30TS00_DEVID 0x2200 86 #define GT30TS00_DEVID_MASK 0xff00 87 88 #define GT34TS02_DEVID 0x3300 89 #define GT34TS02_DEVID_MASK 0xff00 90 91 /* IDT */ 92 #define TSE2004_DEVID 0x2200 93 #define TSE2004_DEVID_MASK 0xff00 94 95 #define TS3000_DEVID 0x2900 /* Also matches TSE2002 */ 96 #define TS3000_DEVID_MASK 0xff00 97 98 #define TS3001_DEVID 0x3000 99 #define TS3001_DEVID_MASK 0xff00 100 101 /* Maxim */ 102 #define MAX6604_DEVID 0x3e00 103 #define MAX6604_DEVID_MASK 0xffff 104 105 /* Microchip */ 106 #define MCP9804_DEVID 0x0200 107 #define MCP9804_DEVID_MASK 0xfffc 108 109 #define MCP9808_DEVID 0x0400 110 #define MCP9808_DEVID_MASK 0xfffc 111 112 #define MCP98242_DEVID 0x2000 113 #define MCP98242_DEVID_MASK 0xfffc 114 115 #define MCP98243_DEVID 0x2100 116 #define MCP98243_DEVID_MASK 0xfffc 117 118 #define MCP98244_DEVID 0x2200 119 #define MCP98244_DEVID_MASK 0xfffc 120 121 #define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */ 122 #define MCP9843_DEVID_MASK 0xfffe 123 124 /* NXP */ 125 #define SE97_DEVID 0xa200 126 #define SE97_DEVID_MASK 0xfffc 127 128 #define SE98_DEVID 0xa100 129 #define SE98_DEVID_MASK 0xfffc 130 131 /* ON Semiconductor */ 132 #define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */ 133 #define CAT6095_DEVID_MASK 0xffe0 134 135 #define CAT34TS02C_DEVID 0x0a00 136 #define CAT34TS02C_DEVID_MASK 0xfff0 137 138 #define CAT34TS04_DEVID 0x2200 139 #define CAT34TS04_DEVID_MASK 0xfff0 140 141 #define N34TS04_DEVID 0x2230 142 #define N34TS04_DEVID_MASK 0xfff0 143 144 /* ST Microelectronics */ 145 #define STTS424_DEVID 0x0101 146 #define STTS424_DEVID_MASK 0xffff 147 148 #define STTS424E_DEVID 0x0000 149 #define STTS424E_DEVID_MASK 0xfffe 150 151 #define STTS2002_DEVID 0x0300 152 #define STTS2002_DEVID_MASK 0xffff 153 154 #define STTS2004_DEVID 0x2201 155 #define STTS2004_DEVID_MASK 0xffff 156 157 #define STTS3000_DEVID 0x0200 158 #define STTS3000_DEVID_MASK 0xffff 159 160 /* Seiko Instruments */ 161 #define S34TS04A_DEVID 0x2221 162 #define S34TS04A_DEVID_MASK 0xffff 163 164 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 }; 165 166 struct jc42_chips { 167 u16 manid; 168 u16 devid; 169 u16 devid_mask; 170 }; 171 172 static struct jc42_chips jc42_chips[] = { 173 { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK }, 174 { ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK }, 175 { ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK }, 176 { GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK }, 177 { GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK }, 178 { IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK }, 179 { IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK }, 180 { IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK }, 181 { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK }, 182 { MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK }, 183 { MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK }, 184 { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK }, 185 { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK }, 186 { MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK }, 187 { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK }, 188 { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK }, 189 { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK }, 190 { ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK }, 191 { ONS_MANID, CAT34TS04_DEVID, CAT34TS04_DEVID_MASK }, 192 { ONS_MANID, N34TS04_DEVID, N34TS04_DEVID_MASK }, 193 { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK }, 194 { SI_MANID, S34TS04A_DEVID, S34TS04A_DEVID_MASK }, 195 { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK }, 196 { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK }, 197 { STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK }, 198 { STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK }, 199 { STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK }, 200 }; 201 202 enum temp_index { 203 t_input = 0, 204 t_crit, 205 t_min, 206 t_max, 207 t_num_temp 208 }; 209 210 static const u8 temp_regs[t_num_temp] = { 211 [t_input] = JC42_REG_TEMP, 212 [t_crit] = JC42_REG_TEMP_CRITICAL, 213 [t_min] = JC42_REG_TEMP_LOWER, 214 [t_max] = JC42_REG_TEMP_UPPER, 215 }; 216 217 /* Each client has this additional data */ 218 struct jc42_data { 219 struct i2c_client *client; 220 struct mutex update_lock; /* protect register access */ 221 bool extended; /* true if extended range supported */ 222 bool valid; 223 unsigned long last_updated; /* In jiffies */ 224 u16 orig_config; /* original configuration */ 225 u16 config; /* current configuration */ 226 u16 temp[t_num_temp];/* Temperatures */ 227 }; 228 229 #define JC42_TEMP_MIN_EXTENDED (-40000) 230 #define JC42_TEMP_MIN 0 231 #define JC42_TEMP_MAX 125000 232 233 static u16 jc42_temp_to_reg(long temp, bool extended) 234 { 235 int ntemp = clamp_val(temp, 236 extended ? JC42_TEMP_MIN_EXTENDED : 237 JC42_TEMP_MIN, JC42_TEMP_MAX); 238 239 /* convert from 0.001 to 0.0625 resolution */ 240 return (ntemp * 2 / 125) & 0x1fff; 241 } 242 243 static int jc42_temp_from_reg(s16 reg) 244 { 245 reg = sign_extend32(reg, 12); 246 247 /* convert from 0.0625 to 0.001 resolution */ 248 return reg * 125 / 2; 249 } 250 251 static struct jc42_data *jc42_update_device(struct device *dev) 252 { 253 struct jc42_data *data = dev_get_drvdata(dev); 254 struct i2c_client *client = data->client; 255 struct jc42_data *ret = data; 256 int i, val; 257 258 mutex_lock(&data->update_lock); 259 260 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 261 for (i = 0; i < t_num_temp; i++) { 262 val = i2c_smbus_read_word_swapped(client, temp_regs[i]); 263 if (val < 0) { 264 ret = ERR_PTR(val); 265 goto abort; 266 } 267 data->temp[i] = val; 268 } 269 data->last_updated = jiffies; 270 data->valid = true; 271 } 272 abort: 273 mutex_unlock(&data->update_lock); 274 return ret; 275 } 276 277 static int jc42_read(struct device *dev, enum hwmon_sensor_types type, 278 u32 attr, int channel, long *val) 279 { 280 struct jc42_data *data = jc42_update_device(dev); 281 int temp, hyst; 282 283 if (IS_ERR(data)) 284 return PTR_ERR(data); 285 286 switch (attr) { 287 case hwmon_temp_input: 288 *val = jc42_temp_from_reg(data->temp[t_input]); 289 return 0; 290 case hwmon_temp_min: 291 *val = jc42_temp_from_reg(data->temp[t_min]); 292 return 0; 293 case hwmon_temp_max: 294 *val = jc42_temp_from_reg(data->temp[t_max]); 295 return 0; 296 case hwmon_temp_crit: 297 *val = jc42_temp_from_reg(data->temp[t_crit]); 298 return 0; 299 case hwmon_temp_max_hyst: 300 temp = jc42_temp_from_reg(data->temp[t_max]); 301 hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK) 302 >> JC42_CFG_HYST_SHIFT]; 303 *val = temp - hyst; 304 return 0; 305 case hwmon_temp_crit_hyst: 306 temp = jc42_temp_from_reg(data->temp[t_crit]); 307 hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK) 308 >> JC42_CFG_HYST_SHIFT]; 309 *val = temp - hyst; 310 return 0; 311 case hwmon_temp_min_alarm: 312 *val = (data->temp[t_input] >> JC42_ALARM_MIN_BIT) & 1; 313 return 0; 314 case hwmon_temp_max_alarm: 315 *val = (data->temp[t_input] >> JC42_ALARM_MAX_BIT) & 1; 316 return 0; 317 case hwmon_temp_crit_alarm: 318 *val = (data->temp[t_input] >> JC42_ALARM_CRIT_BIT) & 1; 319 return 0; 320 default: 321 return -EOPNOTSUPP; 322 } 323 } 324 325 static int jc42_write(struct device *dev, enum hwmon_sensor_types type, 326 u32 attr, int channel, long val) 327 { 328 struct jc42_data *data = dev_get_drvdata(dev); 329 struct i2c_client *client = data->client; 330 int diff, hyst; 331 int ret; 332 333 mutex_lock(&data->update_lock); 334 335 switch (attr) { 336 case hwmon_temp_min: 337 data->temp[t_min] = jc42_temp_to_reg(val, data->extended); 338 ret = i2c_smbus_write_word_swapped(client, temp_regs[t_min], 339 data->temp[t_min]); 340 break; 341 case hwmon_temp_max: 342 data->temp[t_max] = jc42_temp_to_reg(val, data->extended); 343 ret = i2c_smbus_write_word_swapped(client, temp_regs[t_max], 344 data->temp[t_max]); 345 break; 346 case hwmon_temp_crit: 347 data->temp[t_crit] = jc42_temp_to_reg(val, data->extended); 348 ret = i2c_smbus_write_word_swapped(client, temp_regs[t_crit], 349 data->temp[t_crit]); 350 break; 351 case hwmon_temp_crit_hyst: 352 /* 353 * JC42.4 compliant chips only support four hysteresis values. 354 * Pick best choice and go from there. 355 */ 356 val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED 357 : JC42_TEMP_MIN) - 6000, 358 JC42_TEMP_MAX); 359 diff = jc42_temp_from_reg(data->temp[t_crit]) - val; 360 hyst = 0; 361 if (diff > 0) { 362 if (diff < 2250) 363 hyst = 1; /* 1.5 degrees C */ 364 else if (diff < 4500) 365 hyst = 2; /* 3.0 degrees C */ 366 else 367 hyst = 3; /* 6.0 degrees C */ 368 } 369 data->config = (data->config & ~JC42_CFG_HYST_MASK) | 370 (hyst << JC42_CFG_HYST_SHIFT); 371 ret = i2c_smbus_write_word_swapped(data->client, 372 JC42_REG_CONFIG, 373 data->config); 374 break; 375 default: 376 ret = -EOPNOTSUPP; 377 break; 378 } 379 380 mutex_unlock(&data->update_lock); 381 382 return ret; 383 } 384 385 static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type, 386 u32 attr, int channel) 387 { 388 const struct jc42_data *data = _data; 389 unsigned int config = data->config; 390 umode_t mode = 0444; 391 392 switch (attr) { 393 case hwmon_temp_min: 394 case hwmon_temp_max: 395 if (!(config & JC42_CFG_EVENT_LOCK)) 396 mode |= 0200; 397 break; 398 case hwmon_temp_crit: 399 if (!(config & JC42_CFG_TCRIT_LOCK)) 400 mode |= 0200; 401 break; 402 case hwmon_temp_crit_hyst: 403 if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK))) 404 mode |= 0200; 405 break; 406 case hwmon_temp_input: 407 case hwmon_temp_max_hyst: 408 case hwmon_temp_min_alarm: 409 case hwmon_temp_max_alarm: 410 case hwmon_temp_crit_alarm: 411 break; 412 default: 413 mode = 0; 414 break; 415 } 416 return mode; 417 } 418 419 /* Return 0 if detection is successful, -ENODEV otherwise */ 420 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info) 421 { 422 struct i2c_adapter *adapter = client->adapter; 423 int i, config, cap, manid, devid; 424 425 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 426 I2C_FUNC_SMBUS_WORD_DATA)) 427 return -ENODEV; 428 429 cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP); 430 config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG); 431 manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID); 432 devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID); 433 434 if (cap < 0 || config < 0 || manid < 0 || devid < 0) 435 return -ENODEV; 436 437 if ((cap & 0xff00) || (config & 0xf800)) 438 return -ENODEV; 439 440 for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) { 441 struct jc42_chips *chip = &jc42_chips[i]; 442 if (manid == chip->manid && 443 (devid & chip->devid_mask) == chip->devid) { 444 strscpy(info->type, "jc42", I2C_NAME_SIZE); 445 return 0; 446 } 447 } 448 return -ENODEV; 449 } 450 451 static const struct hwmon_channel_info *jc42_info[] = { 452 HWMON_CHANNEL_INFO(chip, 453 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL), 454 HWMON_CHANNEL_INFO(temp, 455 HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | 456 HWMON_T_CRIT | HWMON_T_MAX_HYST | 457 HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM | 458 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM), 459 NULL 460 }; 461 462 static const struct hwmon_ops jc42_hwmon_ops = { 463 .is_visible = jc42_is_visible, 464 .read = jc42_read, 465 .write = jc42_write, 466 }; 467 468 static const struct hwmon_chip_info jc42_chip_info = { 469 .ops = &jc42_hwmon_ops, 470 .info = jc42_info, 471 }; 472 473 static int jc42_probe(struct i2c_client *client) 474 { 475 struct device *dev = &client->dev; 476 struct device *hwmon_dev; 477 struct jc42_data *data; 478 int config, cap; 479 480 data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL); 481 if (!data) 482 return -ENOMEM; 483 484 data->client = client; 485 i2c_set_clientdata(client, data); 486 mutex_init(&data->update_lock); 487 488 cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP); 489 if (cap < 0) 490 return cap; 491 492 data->extended = !!(cap & JC42_CAP_RANGE); 493 494 if (device_property_read_bool(dev, "smbus-timeout-disable")) { 495 int smbus; 496 497 /* 498 * Not all chips support this register, but from a 499 * quick read of various datasheets no chip appears 500 * incompatible with the below attempt to disable 501 * the timeout. And the whole thing is opt-in... 502 */ 503 smbus = i2c_smbus_read_word_swapped(client, JC42_REG_SMBUS); 504 if (smbus < 0) 505 return smbus; 506 i2c_smbus_write_word_swapped(client, JC42_REG_SMBUS, 507 smbus | SMBUS_STMOUT); 508 } 509 510 config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG); 511 if (config < 0) 512 return config; 513 514 data->orig_config = config; 515 if (config & JC42_CFG_SHUTDOWN) { 516 config &= ~JC42_CFG_SHUTDOWN; 517 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config); 518 } 519 data->config = config; 520 521 hwmon_dev = devm_hwmon_device_register_with_info(dev, "jc42", 522 data, &jc42_chip_info, 523 NULL); 524 return PTR_ERR_OR_ZERO(hwmon_dev); 525 } 526 527 static void jc42_remove(struct i2c_client *client) 528 { 529 struct jc42_data *data = i2c_get_clientdata(client); 530 531 /* Restore original configuration except hysteresis */ 532 if ((data->config & ~JC42_CFG_HYST_MASK) != 533 (data->orig_config & ~JC42_CFG_HYST_MASK)) { 534 int config; 535 536 config = (data->orig_config & ~JC42_CFG_HYST_MASK) 537 | (data->config & JC42_CFG_HYST_MASK); 538 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config); 539 } 540 } 541 542 #ifdef CONFIG_PM 543 544 static int jc42_suspend(struct device *dev) 545 { 546 struct jc42_data *data = dev_get_drvdata(dev); 547 548 data->config |= JC42_CFG_SHUTDOWN; 549 i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG, 550 data->config); 551 return 0; 552 } 553 554 static int jc42_resume(struct device *dev) 555 { 556 struct jc42_data *data = dev_get_drvdata(dev); 557 558 data->config &= ~JC42_CFG_SHUTDOWN; 559 i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG, 560 data->config); 561 return 0; 562 } 563 564 static const struct dev_pm_ops jc42_dev_pm_ops = { 565 .suspend = jc42_suspend, 566 .resume = jc42_resume, 567 }; 568 569 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops) 570 #else 571 #define JC42_DEV_PM_OPS NULL 572 #endif /* CONFIG_PM */ 573 574 static const struct i2c_device_id jc42_id[] = { 575 { "jc42", 0 }, 576 { } 577 }; 578 MODULE_DEVICE_TABLE(i2c, jc42_id); 579 580 #ifdef CONFIG_OF 581 static const struct of_device_id jc42_of_ids[] = { 582 { .compatible = "jedec,jc-42.4-temp", }, 583 { } 584 }; 585 MODULE_DEVICE_TABLE(of, jc42_of_ids); 586 #endif 587 588 static struct i2c_driver jc42_driver = { 589 .class = I2C_CLASS_SPD | I2C_CLASS_HWMON, 590 .driver = { 591 .name = "jc42", 592 .pm = JC42_DEV_PM_OPS, 593 .of_match_table = of_match_ptr(jc42_of_ids), 594 }, 595 .probe_new = jc42_probe, 596 .remove = jc42_remove, 597 .id_table = jc42_id, 598 .detect = jc42_detect, 599 .address_list = normal_i2c, 600 }; 601 602 module_i2c_driver(jc42_driver); 603 604 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); 605 MODULE_DESCRIPTION("JC42 driver"); 606 MODULE_LICENSE("GPL"); 607