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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 | // SPDX-License-Identifier: GPL-2.0+ /* * Hardware monitoring driver for EMC2305 fan controller * * Copyright (C) 2022 Nvidia Technologies Ltd. */ #include <linux/err.h> #include <linux/hwmon.h> #include <linux/i2c.h> #include <linux/module.h> #include <linux/platform_data/emc2305.h> #include <linux/thermal.h> static const unsigned short emc2305_normal_i2c[] = { 0x27, 0x2c, 0x2d, 0x2e, 0x2f, 0x4c, 0x4d, I2C_CLIENT_END }; #define EMC2305_REG_DRIVE_FAIL_STATUS 0x27 #define EMC2305_REG_VENDOR 0xfe #define EMC2305_FAN_MAX 0xff #define EMC2305_FAN_MIN 0x00 #define EMC2305_FAN_MAX_STATE 10 #define EMC2305_DEVICE 0x34 #define EMC2305_VENDOR 0x5d #define EMC2305_REG_PRODUCT_ID 0xfd #define EMC2305_TACH_REGS_UNUSE_BITS 3 #define EMC2305_TACH_CNT_MULTIPLIER 0x02 #define EMC2305_TACH_RANGE_MIN 480 #define EMC2305_PWM_DUTY2STATE(duty, max_state, pwm_max) \ DIV_ROUND_CLOSEST((duty) * (max_state), (pwm_max)) #define EMC2305_PWM_STATE2DUTY(state, max_state, pwm_max) \ DIV_ROUND_CLOSEST((state) * (pwm_max), (max_state)) /* * Factor by equations [2] and [3] from data sheet; valid for fans where the number of edges * equal (poles * 2 + 1). */ #define EMC2305_RPM_FACTOR 3932160 #define EMC2305_REG_FAN_DRIVE(n) (0x30 + 0x10 * (n)) #define EMC2305_REG_FAN_MIN_DRIVE(n) (0x38 + 0x10 * (n)) #define EMC2305_REG_FAN_TACH(n) (0x3e + 0x10 * (n)) enum emc230x_product_id { EMC2305 = 0x34, EMC2303 = 0x35, EMC2302 = 0x36, EMC2301 = 0x37, }; static const struct i2c_device_id emc2305_ids[] = { { "emc2305", 0 }, { "emc2303", 0 }, { "emc2302", 0 }, { "emc2301", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, emc2305_ids); /** * struct emc2305_cdev_data - device-specific cooling device state * @cdev: cooling device * @cur_state: cooling current state * @last_hwmon_state: last cooling state updated by hwmon subsystem * @last_thermal_state: last cooling state updated by thermal subsystem * * The 'last_hwmon_state' and 'last_thermal_state' fields are provided to support fan low limit * speed feature. The purpose of this feature is to provides ability to limit fan speed * according to some system wise considerations, like absence of some replaceable units (PSU or * line cards), high system ambient temperature, unreliable transceivers temperature sensing or * some other factors which indirectly impacts system's airflow * Fan low limit feature is supported through 'hwmon' interface: 'hwmon' 'pwm' attribute is * used for setting low limit for fan speed in case 'thermal' subsystem is configured in * kernel. In this case setting fan speed through 'hwmon' will never let the 'thermal' * subsystem to select a lower duty cycle than the duty cycle selected with the 'pwm' * attribute. * From other side, fan speed is to be updated in hardware through 'pwm' only in case the * requested fan speed is above last speed set by 'thermal' subsystem, otherwise requested fan * speed will be just stored with no PWM update. */ struct emc2305_cdev_data { struct thermal_cooling_device *cdev; unsigned int cur_state; unsigned long last_hwmon_state; unsigned long last_thermal_state; }; /** * struct emc2305_data - device-specific data * @client: i2c client * @hwmon_dev: hwmon device * @max_state: maximum cooling state of the cooling device * @pwm_num: number of PWM channels * @pwm_separate: separate PWM settings for every channel * @pwm_min: array of minimum PWM per channel * @cdev_data: array of cooling devices data */ struct emc2305_data { struct i2c_client *client; struct device *hwmon_dev; u8 max_state; u8 pwm_num; bool pwm_separate; u8 pwm_min[EMC2305_PWM_MAX]; struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX]; }; static char *emc2305_fan_name[] = { "emc2305_fan", "emc2305_fan1", "emc2305_fan2", "emc2305_fan3", "emc2305_fan4", "emc2305_fan5", }; static void emc2305_unset_tz(struct device *dev); static int emc2305_get_max_channel(const struct emc2305_data *data) { return data->pwm_num; } static int emc2305_get_cdev_idx(struct thermal_cooling_device *cdev) { struct emc2305_data *data = cdev->devdata; size_t len = strlen(cdev->type); int ret; if (len <= 0) return -EINVAL; /* * Returns index of cooling device 0..4 in case of separate PWM setting. * Zero index is used in case of one common PWM setting. * If the mode is not set as pwm_separate, all PWMs are to be bound * to the common thermal zone and should work at the same speed * to perform cooling for the same thermal junction. * Otherwise, return specific channel that will be used in bound * related PWM to the thermal zone. */ if (!data->pwm_separate) return 0; ret = cdev->type[len - 1]; switch (ret) { case '1' ... '5': return ret - '1'; default: break; } return -EINVAL; } static int emc2305_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state) { int cdev_idx; struct emc2305_data *data = cdev->devdata; cdev_idx = emc2305_get_cdev_idx(cdev); if (cdev_idx < 0) return cdev_idx; *state = data->cdev_data[cdev_idx].cur_state; return 0; } static int emc2305_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state) { struct emc2305_data *data = cdev->devdata; *state = data->max_state; return 0; } static int __emc2305_set_cur_state(struct emc2305_data *data, int cdev_idx, unsigned long state) { int ret; struct i2c_client *client = data->client; u8 val, i; state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state); val = EMC2305_PWM_STATE2DUTY(state, data->max_state, EMC2305_FAN_MAX); data->cdev_data[cdev_idx].cur_state = state; if (data->pwm_separate) { ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val); if (ret < 0) return ret; } else { /* * Set the same PWM value in all channels * if common PWM channel is used. */ for (i = 0; i < data->pwm_num; i++) { ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val); if (ret < 0) return ret; } } return 0; } static int emc2305_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) { int cdev_idx, ret; struct emc2305_data *data = cdev->devdata; if (state > data->max_state) return -EINVAL; cdev_idx = emc2305_get_cdev_idx(cdev); if (cdev_idx < 0) return cdev_idx; /* Save thermal state. */ data->cdev_data[cdev_idx].last_thermal_state = state; ret = __emc2305_set_cur_state(data, cdev_idx, state); if (ret < 0) return ret; return 0; } static const struct thermal_cooling_device_ops emc2305_cooling_ops = { .get_max_state = emc2305_get_max_state, .get_cur_state = emc2305_get_cur_state, .set_cur_state = emc2305_set_cur_state, }; static int emc2305_show_fault(struct device *dev, int channel) { struct emc2305_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int status_reg; status_reg = i2c_smbus_read_byte_data(client, EMC2305_REG_DRIVE_FAIL_STATUS); if (status_reg < 0) return status_reg; return status_reg & (1 << channel) ? 1 : 0; } static int emc2305_show_fan(struct device *dev, int channel) { struct emc2305_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int ret; ret = i2c_smbus_read_word_swapped(client, EMC2305_REG_FAN_TACH(channel)); if (ret <= 0) return ret; ret = ret >> EMC2305_TACH_REGS_UNUSE_BITS; ret = EMC2305_RPM_FACTOR / ret; if (ret <= EMC2305_TACH_RANGE_MIN) return 0; return ret * EMC2305_TACH_CNT_MULTIPLIER; } static int emc2305_show_pwm(struct device *dev, int channel) { struct emc2305_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; return i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_DRIVE(channel)); } static int emc2305_set_pwm(struct device *dev, long val, int channel) { struct emc2305_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int ret; if (val < data->pwm_min[channel] || val > EMC2305_FAN_MAX) return -EINVAL; ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val); if (ret < 0) return ret; data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state, EMC2305_FAN_MAX); return 0; } static int emc2305_set_single_tz(struct device *dev, int idx) { struct emc2305_data *data = dev_get_drvdata(dev); long pwm; int i, cdev_idx, ret; cdev_idx = (idx) ? idx - 1 : 0; pwm = data->pwm_min[cdev_idx]; data->cdev_data[cdev_idx].cdev = thermal_cooling_device_register(emc2305_fan_name[idx], data, &emc2305_cooling_ops); if (IS_ERR(data->cdev_data[cdev_idx].cdev)) { dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]); return PTR_ERR(data->cdev_data[cdev_idx].cdev); } /* Set minimal PWM speed. */ if (data->pwm_separate) { ret = emc2305_set_pwm(dev, pwm, cdev_idx); if (ret < 0) return ret; } else { for (i = 0; i < data->pwm_num; i++) { ret = emc2305_set_pwm(dev, pwm, i); if (ret < 0) return ret; } } data->cdev_data[cdev_idx].cur_state = EMC2305_PWM_DUTY2STATE(data->pwm_min[cdev_idx], data->max_state, EMC2305_FAN_MAX); data->cdev_data[cdev_idx].last_hwmon_state = EMC2305_PWM_DUTY2STATE(data->pwm_min[cdev_idx], data->max_state, EMC2305_FAN_MAX); return 0; } static int emc2305_set_tz(struct device *dev) { struct emc2305_data *data = dev_get_drvdata(dev); int i, ret; if (!data->pwm_separate) return emc2305_set_single_tz(dev, 0); for (i = 0; i < data->pwm_num; i++) { ret = emc2305_set_single_tz(dev, i + 1); if (ret) goto thermal_cooling_device_register_fail; } return 0; thermal_cooling_device_register_fail: emc2305_unset_tz(dev); return ret; } static void emc2305_unset_tz(struct device *dev) { struct emc2305_data *data = dev_get_drvdata(dev); int i; /* Unregister cooling device. */ for (i = 0; i < EMC2305_PWM_MAX; i++) if (data->cdev_data[i].cdev) thermal_cooling_device_unregister(data->cdev_data[i].cdev); } static umode_t emc2305_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { int max_channel = emc2305_get_max_channel(data); /* Don't show channels which are not physically connected. */ if (channel >= max_channel) return 0; switch (type) { case hwmon_fan: switch (attr) { case hwmon_fan_input: return 0444; case hwmon_fan_fault: return 0444; default: break; } break; case hwmon_pwm: switch (attr) { case hwmon_pwm_input: return 0644; default: break; } break; default: break; } return 0; }; static int emc2305_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val) { struct emc2305_data *data = dev_get_drvdata(dev); int cdev_idx; switch (type) { case hwmon_pwm: switch (attr) { case hwmon_pwm_input: /* If thermal is configured - handle PWM limit setting. */ if (IS_REACHABLE(CONFIG_THERMAL)) { if (data->pwm_separate) cdev_idx = channel; else cdev_idx = 0; data->cdev_data[cdev_idx].last_hwmon_state = EMC2305_PWM_DUTY2STATE(val, data->max_state, EMC2305_FAN_MAX); /* * Update PWM only in case requested state is not less than the * last thermal state. */ if (data->cdev_data[cdev_idx].last_hwmon_state >= data->cdev_data[cdev_idx].last_thermal_state) return __emc2305_set_cur_state(data, cdev_idx, data->cdev_data[cdev_idx].last_hwmon_state); return 0; } return emc2305_set_pwm(dev, val, channel); default: break; } break; default: break; } return -EOPNOTSUPP; }; static int emc2305_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { int ret; switch (type) { case hwmon_fan: switch (attr) { case hwmon_fan_input: ret = emc2305_show_fan(dev, channel); if (ret < 0) return ret; *val = ret; return 0; case hwmon_fan_fault: ret = emc2305_show_fault(dev, channel); if (ret < 0) return ret; *val = ret; return 0; default: break; } break; case hwmon_pwm: switch (attr) { case hwmon_pwm_input: ret = emc2305_show_pwm(dev, channel); if (ret < 0) return ret; *val = ret; return 0; default: break; } break; default: break; } return -EOPNOTSUPP; }; static const struct hwmon_ops emc2305_ops = { .is_visible = emc2305_is_visible, .read = emc2305_read, .write = emc2305_write, }; static const struct hwmon_channel_info *emc2305_info[] = { HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_FAULT, HWMON_F_INPUT | HWMON_F_FAULT, HWMON_F_INPUT | HWMON_F_FAULT, HWMON_F_INPUT | HWMON_F_FAULT, HWMON_F_INPUT | HWMON_F_FAULT), HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT, HWMON_PWM_INPUT, HWMON_PWM_INPUT, HWMON_PWM_INPUT, HWMON_PWM_INPUT), NULL }; static const struct hwmon_chip_info emc2305_chip_info = { .ops = &emc2305_ops, .info = emc2305_info, }; static int emc2305_identify(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct emc2305_data *data = i2c_get_clientdata(client); int ret; ret = i2c_smbus_read_byte_data(client, EMC2305_REG_PRODUCT_ID); if (ret < 0) return ret; switch (ret) { case EMC2305: data->pwm_num = 5; break; case EMC2303: data->pwm_num = 3; break; case EMC2302: data->pwm_num = 2; break; case EMC2301: data->pwm_num = 1; break; default: return -ENODEV; } return 0; } static int emc2305_probe(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; struct device *dev = &client->dev; struct emc2305_data *data; struct emc2305_platform_data *pdata; int vendor; int ret; int i; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; vendor = i2c_smbus_read_byte_data(client, EMC2305_REG_VENDOR); if (vendor != EMC2305_VENDOR) return -ENODEV; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; i2c_set_clientdata(client, data); data->client = client; ret = emc2305_identify(dev); if (ret) return ret; pdata = dev_get_platdata(&client->dev); if (pdata) { if (!pdata->max_state || pdata->max_state > EMC2305_FAN_MAX_STATE) return -EINVAL; data->max_state = pdata->max_state; /* * Validate a number of active PWM channels. Note that * configured number can be less than the actual maximum * supported by the device. */ if (!pdata->pwm_num || pdata->pwm_num > EMC2305_PWM_MAX) return -EINVAL; data->pwm_num = pdata->pwm_num; data->pwm_separate = pdata->pwm_separate; for (i = 0; i < EMC2305_PWM_MAX; i++) data->pwm_min[i] = pdata->pwm_min[i]; } else { data->max_state = EMC2305_FAN_MAX_STATE; data->pwm_separate = false; for (i = 0; i < EMC2305_PWM_MAX; i++) data->pwm_min[i] = EMC2305_FAN_MIN; } data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data, &emc2305_chip_info, NULL); if (IS_ERR(data->hwmon_dev)) return PTR_ERR(data->hwmon_dev); if (IS_REACHABLE(CONFIG_THERMAL)) { ret = emc2305_set_tz(dev); if (ret != 0) return ret; } for (i = 0; i < data->pwm_num; i++) { ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i), data->pwm_min[i]); if (ret < 0) return ret; } return 0; } static void emc2305_remove(struct i2c_client *client) { struct device *dev = &client->dev; if (IS_REACHABLE(CONFIG_THERMAL)) emc2305_unset_tz(dev); } static struct i2c_driver emc2305_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "emc2305", }, .probe_new = emc2305_probe, .remove = emc2305_remove, .id_table = emc2305_ids, .address_list = emc2305_normal_i2c, }; module_i2c_driver(emc2305_driver); MODULE_AUTHOR("Nvidia"); MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver"); MODULE_LICENSE("GPL"); |