1 /* 2 * Copyright 2013 Freescale Semiconductor, Inc. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 */ 9 10 #include <linux/clk.h> 11 #include <linux/cpu_cooling.h> 12 #include <linux/cpufreq.h> 13 #include <linux/delay.h> 14 #include <linux/device.h> 15 #include <linux/init.h> 16 #include <linux/interrupt.h> 17 #include <linux/io.h> 18 #include <linux/kernel.h> 19 #include <linux/mfd/syscon.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/platform_device.h> 23 #include <linux/regmap.h> 24 #include <linux/slab.h> 25 #include <linux/thermal.h> 26 #include <linux/types.h> 27 28 #define REG_SET 0x4 29 #define REG_CLR 0x8 30 #define REG_TOG 0xc 31 32 #define MISC0 0x0150 33 #define MISC0_REFTOP_SELBIASOFF (1 << 3) 34 35 #define TEMPSENSE0 0x0180 36 #define TEMPSENSE0_ALARM_VALUE_SHIFT 20 37 #define TEMPSENSE0_ALARM_VALUE_MASK (0xfff << TEMPSENSE0_ALARM_VALUE_SHIFT) 38 #define TEMPSENSE0_TEMP_CNT_SHIFT 8 39 #define TEMPSENSE0_TEMP_CNT_MASK (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT) 40 #define TEMPSENSE0_FINISHED (1 << 2) 41 #define TEMPSENSE0_MEASURE_TEMP (1 << 1) 42 #define TEMPSENSE0_POWER_DOWN (1 << 0) 43 44 #define TEMPSENSE1 0x0190 45 #define TEMPSENSE1_MEASURE_FREQ 0xffff 46 47 #define OCOTP_ANA1 0x04e0 48 49 /* The driver supports 1 passive trip point and 1 critical trip point */ 50 enum imx_thermal_trip { 51 IMX_TRIP_PASSIVE, 52 IMX_TRIP_CRITICAL, 53 IMX_TRIP_NUM, 54 }; 55 56 /* 57 * It defines the temperature in millicelsius for passive trip point 58 * that will trigger cooling action when crossed. 59 */ 60 #define IMX_TEMP_PASSIVE 85000 61 62 #define IMX_POLLING_DELAY 2000 /* millisecond */ 63 #define IMX_PASSIVE_DELAY 1000 64 65 #define FACTOR0 10000000 66 #define FACTOR1 15976 67 #define FACTOR2 4297157 68 69 struct imx_thermal_data { 70 struct thermal_zone_device *tz; 71 struct thermal_cooling_device *cdev; 72 enum thermal_device_mode mode; 73 struct regmap *tempmon; 74 u32 c1, c2; /* See formula in imx_get_sensor_data() */ 75 unsigned long temp_passive; 76 unsigned long temp_critical; 77 unsigned long alarm_temp; 78 unsigned long last_temp; 79 bool irq_enabled; 80 int irq; 81 struct clk *thermal_clk; 82 }; 83 84 static void imx_set_alarm_temp(struct imx_thermal_data *data, 85 signed long alarm_temp) 86 { 87 struct regmap *map = data->tempmon; 88 int alarm_value; 89 90 data->alarm_temp = alarm_temp; 91 alarm_value = (data->c2 - alarm_temp) / data->c1; 92 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK); 93 regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value << 94 TEMPSENSE0_ALARM_VALUE_SHIFT); 95 } 96 97 static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp) 98 { 99 struct imx_thermal_data *data = tz->devdata; 100 struct regmap *map = data->tempmon; 101 unsigned int n_meas; 102 bool wait; 103 u32 val; 104 105 if (data->mode == THERMAL_DEVICE_ENABLED) { 106 /* Check if a measurement is currently in progress */ 107 regmap_read(map, TEMPSENSE0, &val); 108 wait = !(val & TEMPSENSE0_FINISHED); 109 } else { 110 /* 111 * Every time we measure the temperature, we will power on the 112 * temperature sensor, enable measurements, take a reading, 113 * disable measurements, power off the temperature sensor. 114 */ 115 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); 116 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); 117 118 wait = true; 119 } 120 121 /* 122 * According to the temp sensor designers, it may require up to ~17us 123 * to complete a measurement. 124 */ 125 if (wait) 126 usleep_range(20, 50); 127 128 regmap_read(map, TEMPSENSE0, &val); 129 130 if (data->mode != THERMAL_DEVICE_ENABLED) { 131 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP); 132 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); 133 } 134 135 if ((val & TEMPSENSE0_FINISHED) == 0) { 136 dev_dbg(&tz->device, "temp measurement never finished\n"); 137 return -EAGAIN; 138 } 139 140 n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT; 141 142 /* See imx_get_sensor_data() for formula derivation */ 143 *temp = data->c2 - n_meas * data->c1; 144 145 /* Update alarm value to next higher trip point */ 146 if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive) 147 imx_set_alarm_temp(data, data->temp_critical); 148 if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) { 149 imx_set_alarm_temp(data, data->temp_passive); 150 dev_dbg(&tz->device, "thermal alarm off: T < %lu\n", 151 data->alarm_temp / 1000); 152 } 153 154 if (*temp != data->last_temp) { 155 dev_dbg(&tz->device, "millicelsius: %ld\n", *temp); 156 data->last_temp = *temp; 157 } 158 159 /* Reenable alarm IRQ if temperature below alarm temperature */ 160 if (!data->irq_enabled && *temp < data->alarm_temp) { 161 data->irq_enabled = true; 162 enable_irq(data->irq); 163 } 164 165 return 0; 166 } 167 168 static int imx_get_mode(struct thermal_zone_device *tz, 169 enum thermal_device_mode *mode) 170 { 171 struct imx_thermal_data *data = tz->devdata; 172 173 *mode = data->mode; 174 175 return 0; 176 } 177 178 static int imx_set_mode(struct thermal_zone_device *tz, 179 enum thermal_device_mode mode) 180 { 181 struct imx_thermal_data *data = tz->devdata; 182 struct regmap *map = data->tempmon; 183 184 if (mode == THERMAL_DEVICE_ENABLED) { 185 tz->polling_delay = IMX_POLLING_DELAY; 186 tz->passive_delay = IMX_PASSIVE_DELAY; 187 188 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); 189 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); 190 191 if (!data->irq_enabled) { 192 data->irq_enabled = true; 193 enable_irq(data->irq); 194 } 195 } else { 196 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP); 197 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); 198 199 tz->polling_delay = 0; 200 tz->passive_delay = 0; 201 202 if (data->irq_enabled) { 203 disable_irq(data->irq); 204 data->irq_enabled = false; 205 } 206 } 207 208 data->mode = mode; 209 thermal_zone_device_update(tz); 210 211 return 0; 212 } 213 214 static int imx_get_trip_type(struct thermal_zone_device *tz, int trip, 215 enum thermal_trip_type *type) 216 { 217 *type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE : 218 THERMAL_TRIP_CRITICAL; 219 return 0; 220 } 221 222 static int imx_get_crit_temp(struct thermal_zone_device *tz, 223 unsigned long *temp) 224 { 225 struct imx_thermal_data *data = tz->devdata; 226 227 *temp = data->temp_critical; 228 return 0; 229 } 230 231 static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip, 232 unsigned long *temp) 233 { 234 struct imx_thermal_data *data = tz->devdata; 235 236 *temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive : 237 data->temp_critical; 238 return 0; 239 } 240 241 static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip, 242 unsigned long temp) 243 { 244 struct imx_thermal_data *data = tz->devdata; 245 246 if (trip == IMX_TRIP_CRITICAL) 247 return -EPERM; 248 249 if (temp > IMX_TEMP_PASSIVE) 250 return -EINVAL; 251 252 data->temp_passive = temp; 253 254 imx_set_alarm_temp(data, temp); 255 256 return 0; 257 } 258 259 static int imx_bind(struct thermal_zone_device *tz, 260 struct thermal_cooling_device *cdev) 261 { 262 int ret; 263 264 ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev, 265 THERMAL_NO_LIMIT, 266 THERMAL_NO_LIMIT); 267 if (ret) { 268 dev_err(&tz->device, 269 "binding zone %s with cdev %s failed:%d\n", 270 tz->type, cdev->type, ret); 271 return ret; 272 } 273 274 return 0; 275 } 276 277 static int imx_unbind(struct thermal_zone_device *tz, 278 struct thermal_cooling_device *cdev) 279 { 280 int ret; 281 282 ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev); 283 if (ret) { 284 dev_err(&tz->device, 285 "unbinding zone %s with cdev %s failed:%d\n", 286 tz->type, cdev->type, ret); 287 return ret; 288 } 289 290 return 0; 291 } 292 293 static struct thermal_zone_device_ops imx_tz_ops = { 294 .bind = imx_bind, 295 .unbind = imx_unbind, 296 .get_temp = imx_get_temp, 297 .get_mode = imx_get_mode, 298 .set_mode = imx_set_mode, 299 .get_trip_type = imx_get_trip_type, 300 .get_trip_temp = imx_get_trip_temp, 301 .get_crit_temp = imx_get_crit_temp, 302 .set_trip_temp = imx_set_trip_temp, 303 }; 304 305 static int imx_get_sensor_data(struct platform_device *pdev) 306 { 307 struct imx_thermal_data *data = platform_get_drvdata(pdev); 308 struct regmap *map; 309 int t1, n1; 310 int ret; 311 u32 val; 312 u64 temp64; 313 314 map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, 315 "fsl,tempmon-data"); 316 if (IS_ERR(map)) { 317 ret = PTR_ERR(map); 318 dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret); 319 return ret; 320 } 321 322 ret = regmap_read(map, OCOTP_ANA1, &val); 323 if (ret) { 324 dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret); 325 return ret; 326 } 327 328 if (val == 0 || val == ~0) { 329 dev_err(&pdev->dev, "invalid sensor calibration data\n"); 330 return -EINVAL; 331 } 332 333 /* 334 * Sensor data layout: 335 * [31:20] - sensor value @ 25C 336 * Use universal formula now and only need sensor value @ 25C 337 * slope = 0.4297157 - (0.0015976 * 25C fuse) 338 */ 339 n1 = val >> 20; 340 t1 = 25; /* t1 always 25C */ 341 342 /* 343 * Derived from linear interpolation: 344 * slope = 0.4297157 - (0.0015976 * 25C fuse) 345 * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0 346 * (Nmeas - n1) / (Tmeas - t1) = slope 347 * We want to reduce this down to the minimum computation necessary 348 * for each temperature read. Also, we want Tmeas in millicelsius 349 * and we don't want to lose precision from integer division. So... 350 * Tmeas = (Nmeas - n1) / slope + t1 351 * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1 352 * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1 353 * Let constant c1 = (-1000 / slope) 354 * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1 355 * Let constant c2 = n1 *c1 + 1000 * t1 356 * milli_Tmeas = c2 - Nmeas * c1 357 */ 358 temp64 = FACTOR0; 359 temp64 *= 1000; 360 do_div(temp64, FACTOR1 * n1 - FACTOR2); 361 data->c1 = temp64; 362 data->c2 = n1 * data->c1 + 1000 * t1; 363 364 /* 365 * Set the default passive cooling trip point, 366 * can be changed from userspace. 367 */ 368 data->temp_passive = IMX_TEMP_PASSIVE; 369 370 /* 371 * The maximum die temperature set to 20 C higher than 372 * IMX_TEMP_PASSIVE. 373 */ 374 data->temp_critical = 1000 * 20 + data->temp_passive; 375 376 return 0; 377 } 378 379 static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev) 380 { 381 struct imx_thermal_data *data = dev; 382 383 disable_irq_nosync(irq); 384 data->irq_enabled = false; 385 386 return IRQ_WAKE_THREAD; 387 } 388 389 static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev) 390 { 391 struct imx_thermal_data *data = dev; 392 393 dev_dbg(&data->tz->device, "THERMAL ALARM: T > %lu\n", 394 data->alarm_temp / 1000); 395 396 thermal_zone_device_update(data->tz); 397 398 return IRQ_HANDLED; 399 } 400 401 static int imx_thermal_probe(struct platform_device *pdev) 402 { 403 struct imx_thermal_data *data; 404 struct cpumask clip_cpus; 405 struct regmap *map; 406 int measure_freq; 407 int ret; 408 409 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 410 if (!data) 411 return -ENOMEM; 412 413 map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon"); 414 if (IS_ERR(map)) { 415 ret = PTR_ERR(map); 416 dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret); 417 return ret; 418 } 419 data->tempmon = map; 420 421 data->irq = platform_get_irq(pdev, 0); 422 if (data->irq < 0) 423 return data->irq; 424 425 ret = devm_request_threaded_irq(&pdev->dev, data->irq, 426 imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread, 427 0, "imx_thermal", data); 428 if (ret < 0) { 429 dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret); 430 return ret; 431 } 432 433 platform_set_drvdata(pdev, data); 434 435 ret = imx_get_sensor_data(pdev); 436 if (ret) { 437 dev_err(&pdev->dev, "failed to get sensor data\n"); 438 return ret; 439 } 440 441 /* Make sure sensor is in known good state for measurements */ 442 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); 443 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP); 444 regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ); 445 regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF); 446 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); 447 448 cpumask_set_cpu(0, &clip_cpus); 449 data->cdev = cpufreq_cooling_register(&clip_cpus); 450 if (IS_ERR(data->cdev)) { 451 ret = PTR_ERR(data->cdev); 452 dev_err(&pdev->dev, 453 "failed to register cpufreq cooling device: %d\n", ret); 454 return ret; 455 } 456 457 data->tz = thermal_zone_device_register("imx_thermal_zone", 458 IMX_TRIP_NUM, 459 BIT(IMX_TRIP_PASSIVE), data, 460 &imx_tz_ops, NULL, 461 IMX_PASSIVE_DELAY, 462 IMX_POLLING_DELAY); 463 if (IS_ERR(data->tz)) { 464 ret = PTR_ERR(data->tz); 465 dev_err(&pdev->dev, 466 "failed to register thermal zone device %d\n", ret); 467 cpufreq_cooling_unregister(data->cdev); 468 return ret; 469 } 470 471 data->thermal_clk = devm_clk_get(&pdev->dev, NULL); 472 if (IS_ERR(data->thermal_clk)) { 473 dev_warn(&pdev->dev, "failed to get thermal clk!\n"); 474 } else { 475 /* 476 * Thermal sensor needs clk on to get correct value, normally 477 * we should enable its clk before taking measurement and disable 478 * clk after measurement is done, but if alarm function is enabled, 479 * hardware will auto measure the temperature periodically, so we 480 * need to keep the clk always on for alarm function. 481 */ 482 ret = clk_prepare_enable(data->thermal_clk); 483 if (ret) 484 dev_warn(&pdev->dev, "failed to enable thermal clk: %d\n", ret); 485 } 486 487 /* Enable measurements at ~ 10 Hz */ 488 regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ); 489 measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */ 490 regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq); 491 imx_set_alarm_temp(data, data->temp_passive); 492 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); 493 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); 494 495 data->irq_enabled = true; 496 data->mode = THERMAL_DEVICE_ENABLED; 497 498 return 0; 499 } 500 501 static int imx_thermal_remove(struct platform_device *pdev) 502 { 503 struct imx_thermal_data *data = platform_get_drvdata(pdev); 504 struct regmap *map = data->tempmon; 505 506 /* Disable measurements */ 507 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); 508 if (!IS_ERR(data->thermal_clk)) 509 clk_disable_unprepare(data->thermal_clk); 510 511 thermal_zone_device_unregister(data->tz); 512 cpufreq_cooling_unregister(data->cdev); 513 514 return 0; 515 } 516 517 #ifdef CONFIG_PM_SLEEP 518 static int imx_thermal_suspend(struct device *dev) 519 { 520 struct imx_thermal_data *data = dev_get_drvdata(dev); 521 struct regmap *map = data->tempmon; 522 523 /* 524 * Need to disable thermal sensor, otherwise, when thermal core 525 * try to get temperature before thermal sensor resume, a wrong 526 * temperature will be read as the thermal sensor is powered 527 * down. 528 */ 529 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP); 530 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); 531 data->mode = THERMAL_DEVICE_DISABLED; 532 533 return 0; 534 } 535 536 static int imx_thermal_resume(struct device *dev) 537 { 538 struct imx_thermal_data *data = dev_get_drvdata(dev); 539 struct regmap *map = data->tempmon; 540 541 /* Enabled thermal sensor after resume */ 542 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); 543 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); 544 data->mode = THERMAL_DEVICE_ENABLED; 545 546 return 0; 547 } 548 #endif 549 550 static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops, 551 imx_thermal_suspend, imx_thermal_resume); 552 553 static const struct of_device_id of_imx_thermal_match[] = { 554 { .compatible = "fsl,imx6q-tempmon", }, 555 { /* end */ } 556 }; 557 MODULE_DEVICE_TABLE(of, of_imx_thermal_match); 558 559 static struct platform_driver imx_thermal = { 560 .driver = { 561 .name = "imx_thermal", 562 .owner = THIS_MODULE, 563 .pm = &imx_thermal_pm_ops, 564 .of_match_table = of_imx_thermal_match, 565 }, 566 .probe = imx_thermal_probe, 567 .remove = imx_thermal_remove, 568 }; 569 module_platform_driver(imx_thermal); 570 571 MODULE_AUTHOR("Freescale Semiconductor, Inc."); 572 MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs"); 573 MODULE_LICENSE("GPL v2"); 574 MODULE_ALIAS("platform:imx-thermal"); 575