1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * A devfreq driver for NVIDIA Tegra SoCs 4 * 5 * Copyright (c) 2014 NVIDIA CORPORATION. All rights reserved. 6 * Copyright (C) 2014 Google, Inc 7 */ 8 9 #include <linux/clk.h> 10 #include <linux/cpufreq.h> 11 #include <linux/devfreq.h> 12 #include <linux/interrupt.h> 13 #include <linux/io.h> 14 #include <linux/irq.h> 15 #include <linux/module.h> 16 #include <linux/of.h> 17 #include <linux/platform_device.h> 18 #include <linux/pm_opp.h> 19 #include <linux/reset.h> 20 #include <linux/workqueue.h> 21 22 #include <soc/tegra/fuse.h> 23 24 #include "governor.h" 25 26 #define ACTMON_GLB_STATUS 0x0 27 #define ACTMON_GLB_PERIOD_CTRL 0x4 28 29 #define ACTMON_DEV_CTRL 0x0 30 #define ACTMON_DEV_CTRL_K_VAL_SHIFT 10 31 #define ACTMON_DEV_CTRL_ENB_PERIODIC BIT(18) 32 #define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN BIT(20) 33 #define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN BIT(21) 34 #define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT 23 35 #define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT 26 36 #define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN BIT(29) 37 #define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN BIT(30) 38 #define ACTMON_DEV_CTRL_ENB BIT(31) 39 40 #define ACTMON_DEV_CTRL_STOP 0x00000000 41 42 #define ACTMON_DEV_UPPER_WMARK 0x4 43 #define ACTMON_DEV_LOWER_WMARK 0x8 44 #define ACTMON_DEV_INIT_AVG 0xc 45 #define ACTMON_DEV_AVG_UPPER_WMARK 0x10 46 #define ACTMON_DEV_AVG_LOWER_WMARK 0x14 47 #define ACTMON_DEV_COUNT_WEIGHT 0x18 48 #define ACTMON_DEV_AVG_COUNT 0x20 49 #define ACTMON_DEV_INTR_STATUS 0x24 50 51 #define ACTMON_INTR_STATUS_CLEAR 0xffffffff 52 53 #define ACTMON_DEV_INTR_CONSECUTIVE_UPPER BIT(31) 54 #define ACTMON_DEV_INTR_CONSECUTIVE_LOWER BIT(30) 55 56 #define ACTMON_ABOVE_WMARK_WINDOW 1 57 #define ACTMON_BELOW_WMARK_WINDOW 3 58 #define ACTMON_BOOST_FREQ_STEP 16000 59 60 /* 61 * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which 62 * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128 63 */ 64 #define ACTMON_AVERAGE_WINDOW_LOG2 6 65 #define ACTMON_SAMPLING_PERIOD 12 /* ms */ 66 #define ACTMON_DEFAULT_AVG_BAND 6 /* 1/10 of % */ 67 68 #define KHZ 1000 69 70 #define KHZ_MAX (ULONG_MAX / KHZ) 71 72 /* Assume that the bus is saturated if the utilization is 25% */ 73 #define BUS_SATURATION_RATIO 25 74 75 /** 76 * struct tegra_devfreq_device_config - configuration specific to an ACTMON 77 * device 78 * 79 * Coefficients and thresholds are percentages unless otherwise noted 80 */ 81 struct tegra_devfreq_device_config { 82 u32 offset; 83 u32 irq_mask; 84 85 /* Factors applied to boost_freq every consecutive watermark breach */ 86 unsigned int boost_up_coeff; 87 unsigned int boost_down_coeff; 88 89 /* Define the watermark bounds when applied to the current avg */ 90 unsigned int boost_up_threshold; 91 unsigned int boost_down_threshold; 92 93 /* 94 * Threshold of activity (cycles translated to kHz) below which the 95 * CPU frequency isn't to be taken into account. This is to avoid 96 * increasing the EMC frequency when the CPU is very busy but not 97 * accessing the bus often. 98 */ 99 u32 avg_dependency_threshold; 100 }; 101 102 enum tegra_actmon_device { 103 MCALL = 0, 104 MCCPU, 105 }; 106 107 static const struct tegra_devfreq_device_config tegra124_device_configs[] = { 108 { 109 /* MCALL: All memory accesses (including from the CPUs) */ 110 .offset = 0x1c0, 111 .irq_mask = 1 << 26, 112 .boost_up_coeff = 200, 113 .boost_down_coeff = 50, 114 .boost_up_threshold = 60, 115 .boost_down_threshold = 40, 116 }, 117 { 118 /* MCCPU: memory accesses from the CPUs */ 119 .offset = 0x200, 120 .irq_mask = 1 << 25, 121 .boost_up_coeff = 800, 122 .boost_down_coeff = 40, 123 .boost_up_threshold = 27, 124 .boost_down_threshold = 10, 125 .avg_dependency_threshold = 16000, /* 16MHz in kHz units */ 126 }, 127 }; 128 129 static const struct tegra_devfreq_device_config tegra30_device_configs[] = { 130 { 131 /* MCALL: All memory accesses (including from the CPUs) */ 132 .offset = 0x1c0, 133 .irq_mask = 1 << 26, 134 .boost_up_coeff = 200, 135 .boost_down_coeff = 50, 136 .boost_up_threshold = 20, 137 .boost_down_threshold = 10, 138 }, 139 { 140 /* MCCPU: memory accesses from the CPUs */ 141 .offset = 0x200, 142 .irq_mask = 1 << 25, 143 .boost_up_coeff = 800, 144 .boost_down_coeff = 40, 145 .boost_up_threshold = 27, 146 .boost_down_threshold = 10, 147 .avg_dependency_threshold = 16000, /* 16MHz in kHz units */ 148 }, 149 }; 150 151 /** 152 * struct tegra_devfreq_device - state specific to an ACTMON device 153 * 154 * Frequencies are in kHz. 155 */ 156 struct tegra_devfreq_device { 157 const struct tegra_devfreq_device_config *config; 158 void __iomem *regs; 159 160 /* Average event count sampled in the last interrupt */ 161 u32 avg_count; 162 163 /* 164 * Extra frequency to increase the target by due to consecutive 165 * watermark breaches. 166 */ 167 unsigned long boost_freq; 168 169 /* Optimal frequency calculated from the stats for this device */ 170 unsigned long target_freq; 171 }; 172 173 struct tegra_devfreq_soc_data { 174 const struct tegra_devfreq_device_config *configs; 175 /* Weight value for count measurements */ 176 unsigned int count_weight; 177 }; 178 179 struct tegra_devfreq { 180 struct devfreq *devfreq; 181 182 struct reset_control *reset; 183 struct clk *clock; 184 void __iomem *regs; 185 186 struct clk *emc_clock; 187 unsigned long max_freq; 188 unsigned long cur_freq; 189 struct notifier_block clk_rate_change_nb; 190 191 struct delayed_work cpufreq_update_work; 192 struct notifier_block cpu_rate_change_nb; 193 194 struct tegra_devfreq_device devices[2]; 195 196 unsigned int irq; 197 198 bool started; 199 200 const struct tegra_devfreq_soc_data *soc; 201 }; 202 203 struct tegra_actmon_emc_ratio { 204 unsigned long cpu_freq; 205 unsigned long emc_freq; 206 }; 207 208 static const struct tegra_actmon_emc_ratio actmon_emc_ratios[] = { 209 { 1400000, KHZ_MAX }, 210 { 1200000, 750000 }, 211 { 1100000, 600000 }, 212 { 1000000, 500000 }, 213 { 800000, 375000 }, 214 { 500000, 200000 }, 215 { 250000, 100000 }, 216 }; 217 218 static u32 actmon_readl(struct tegra_devfreq *tegra, u32 offset) 219 { 220 return readl_relaxed(tegra->regs + offset); 221 } 222 223 static void actmon_writel(struct tegra_devfreq *tegra, u32 val, u32 offset) 224 { 225 writel_relaxed(val, tegra->regs + offset); 226 } 227 228 static u32 device_readl(struct tegra_devfreq_device *dev, u32 offset) 229 { 230 return readl_relaxed(dev->regs + offset); 231 } 232 233 static void device_writel(struct tegra_devfreq_device *dev, u32 val, 234 u32 offset) 235 { 236 writel_relaxed(val, dev->regs + offset); 237 } 238 239 static unsigned long do_percent(unsigned long long val, unsigned int pct) 240 { 241 val = val * pct; 242 do_div(val, 100); 243 244 /* 245 * High freq + high boosting percent + large polling interval are 246 * resulting in integer overflow when watermarks are calculated. 247 */ 248 return min_t(u64, val, U32_MAX); 249 } 250 251 static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, 252 struct tegra_devfreq_device *dev) 253 { 254 u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ; 255 u32 band = avg_band_freq * tegra->devfreq->profile->polling_ms; 256 u32 avg; 257 258 avg = min(dev->avg_count, U32_MAX - band); 259 device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK); 260 261 avg = max(dev->avg_count, band); 262 device_writel(dev, avg - band, ACTMON_DEV_AVG_LOWER_WMARK); 263 } 264 265 static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra, 266 struct tegra_devfreq_device *dev) 267 { 268 u32 val = tegra->cur_freq * tegra->devfreq->profile->polling_ms; 269 270 device_writel(dev, do_percent(val, dev->config->boost_up_threshold), 271 ACTMON_DEV_UPPER_WMARK); 272 273 device_writel(dev, do_percent(val, dev->config->boost_down_threshold), 274 ACTMON_DEV_LOWER_WMARK); 275 } 276 277 static void actmon_isr_device(struct tegra_devfreq *tegra, 278 struct tegra_devfreq_device *dev) 279 { 280 u32 intr_status, dev_ctrl; 281 282 dev->avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); 283 tegra_devfreq_update_avg_wmark(tegra, dev); 284 285 intr_status = device_readl(dev, ACTMON_DEV_INTR_STATUS); 286 dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL); 287 288 if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) { 289 /* 290 * new_boost = min(old_boost * up_coef + step, max_freq) 291 */ 292 dev->boost_freq = do_percent(dev->boost_freq, 293 dev->config->boost_up_coeff); 294 dev->boost_freq += ACTMON_BOOST_FREQ_STEP; 295 296 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 297 298 if (dev->boost_freq >= tegra->max_freq) { 299 dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 300 dev->boost_freq = tegra->max_freq; 301 } 302 } else if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) { 303 /* 304 * new_boost = old_boost * down_coef 305 * or 0 if (old_boost * down_coef < step / 2) 306 */ 307 dev->boost_freq = do_percent(dev->boost_freq, 308 dev->config->boost_down_coeff); 309 310 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 311 312 if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1)) { 313 dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 314 dev->boost_freq = 0; 315 } 316 } 317 318 device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL); 319 320 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS); 321 } 322 323 static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra, 324 unsigned long cpu_freq) 325 { 326 unsigned int i; 327 const struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios; 328 329 for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) { 330 if (cpu_freq >= ratio->cpu_freq) { 331 if (ratio->emc_freq >= tegra->max_freq) 332 return tegra->max_freq; 333 else 334 return ratio->emc_freq; 335 } 336 } 337 338 return 0; 339 } 340 341 static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra, 342 struct tegra_devfreq_device *dev) 343 { 344 unsigned int avg_sustain_coef; 345 unsigned long target_freq; 346 347 target_freq = dev->avg_count / tegra->devfreq->profile->polling_ms; 348 avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold; 349 target_freq = do_percent(target_freq, avg_sustain_coef); 350 351 return target_freq; 352 } 353 354 static void actmon_update_target(struct tegra_devfreq *tegra, 355 struct tegra_devfreq_device *dev) 356 { 357 unsigned long cpu_freq = 0; 358 unsigned long static_cpu_emc_freq = 0; 359 360 dev->target_freq = actmon_device_target_freq(tegra, dev); 361 362 if (dev->config->avg_dependency_threshold && 363 dev->config->avg_dependency_threshold <= dev->target_freq) { 364 cpu_freq = cpufreq_quick_get(0); 365 static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq); 366 367 dev->target_freq += dev->boost_freq; 368 dev->target_freq = max(dev->target_freq, static_cpu_emc_freq); 369 } else { 370 dev->target_freq += dev->boost_freq; 371 } 372 } 373 374 static irqreturn_t actmon_thread_isr(int irq, void *data) 375 { 376 struct tegra_devfreq *tegra = data; 377 bool handled = false; 378 unsigned int i; 379 u32 val; 380 381 mutex_lock(&tegra->devfreq->lock); 382 383 val = actmon_readl(tegra, ACTMON_GLB_STATUS); 384 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 385 if (val & tegra->devices[i].config->irq_mask) { 386 actmon_isr_device(tegra, tegra->devices + i); 387 handled = true; 388 } 389 } 390 391 if (handled) 392 update_devfreq(tegra->devfreq); 393 394 mutex_unlock(&tegra->devfreq->lock); 395 396 return handled ? IRQ_HANDLED : IRQ_NONE; 397 } 398 399 static int tegra_actmon_clk_notify_cb(struct notifier_block *nb, 400 unsigned long action, void *ptr) 401 { 402 struct clk_notifier_data *data = ptr; 403 struct tegra_devfreq *tegra; 404 struct tegra_devfreq_device *dev; 405 unsigned int i; 406 407 if (action != POST_RATE_CHANGE) 408 return NOTIFY_OK; 409 410 tegra = container_of(nb, struct tegra_devfreq, clk_rate_change_nb); 411 412 tegra->cur_freq = data->new_rate / KHZ; 413 414 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 415 dev = &tegra->devices[i]; 416 417 tegra_devfreq_update_wmark(tegra, dev); 418 } 419 420 return NOTIFY_OK; 421 } 422 423 static void tegra_actmon_delayed_update(struct work_struct *work) 424 { 425 struct tegra_devfreq *tegra = container_of(work, struct tegra_devfreq, 426 cpufreq_update_work.work); 427 428 mutex_lock(&tegra->devfreq->lock); 429 update_devfreq(tegra->devfreq); 430 mutex_unlock(&tegra->devfreq->lock); 431 } 432 433 static unsigned long 434 tegra_actmon_cpufreq_contribution(struct tegra_devfreq *tegra, 435 unsigned int cpu_freq) 436 { 437 struct tegra_devfreq_device *actmon_dev = &tegra->devices[MCCPU]; 438 unsigned long static_cpu_emc_freq, dev_freq; 439 440 dev_freq = actmon_device_target_freq(tegra, actmon_dev); 441 442 /* check whether CPU's freq is taken into account at all */ 443 if (dev_freq < actmon_dev->config->avg_dependency_threshold) 444 return 0; 445 446 static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq); 447 448 if (dev_freq + actmon_dev->boost_freq >= static_cpu_emc_freq) 449 return 0; 450 451 return static_cpu_emc_freq; 452 } 453 454 static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb, 455 unsigned long action, void *ptr) 456 { 457 struct cpufreq_freqs *freqs = ptr; 458 struct tegra_devfreq *tegra; 459 unsigned long old, new, delay; 460 461 if (action != CPUFREQ_POSTCHANGE) 462 return NOTIFY_OK; 463 464 tegra = container_of(nb, struct tegra_devfreq, cpu_rate_change_nb); 465 466 /* 467 * Quickly check whether CPU frequency should be taken into account 468 * at all, without blocking CPUFreq's core. 469 */ 470 if (mutex_trylock(&tegra->devfreq->lock)) { 471 old = tegra_actmon_cpufreq_contribution(tegra, freqs->old); 472 new = tegra_actmon_cpufreq_contribution(tegra, freqs->new); 473 mutex_unlock(&tegra->devfreq->lock); 474 475 /* 476 * If CPU's frequency shouldn't be taken into account at 477 * the moment, then there is no need to update the devfreq's 478 * state because ISR will re-check CPU's frequency on the 479 * next interrupt. 480 */ 481 if (old == new) 482 return NOTIFY_OK; 483 } 484 485 /* 486 * CPUFreq driver should support CPUFREQ_ASYNC_NOTIFICATION in order 487 * to allow asynchronous notifications. This means we can't block 488 * here for too long, otherwise CPUFreq's core will complain with a 489 * warning splat. 490 */ 491 delay = msecs_to_jiffies(ACTMON_SAMPLING_PERIOD); 492 schedule_delayed_work(&tegra->cpufreq_update_work, delay); 493 494 return NOTIFY_OK; 495 } 496 497 static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, 498 struct tegra_devfreq_device *dev) 499 { 500 u32 val = 0; 501 502 /* reset boosting on governor's restart */ 503 dev->boost_freq = 0; 504 505 dev->target_freq = tegra->cur_freq; 506 507 dev->avg_count = tegra->cur_freq * tegra->devfreq->profile->polling_ms; 508 device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG); 509 510 tegra_devfreq_update_avg_wmark(tegra, dev); 511 tegra_devfreq_update_wmark(tegra, dev); 512 513 device_writel(dev, tegra->soc->count_weight, ACTMON_DEV_COUNT_WEIGHT); 514 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS); 515 516 val |= ACTMON_DEV_CTRL_ENB_PERIODIC; 517 val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1) 518 << ACTMON_DEV_CTRL_K_VAL_SHIFT; 519 val |= (ACTMON_BELOW_WMARK_WINDOW - 1) 520 << ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT; 521 val |= (ACTMON_ABOVE_WMARK_WINDOW - 1) 522 << ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT; 523 val |= ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN; 524 val |= ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN; 525 val |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 526 val |= ACTMON_DEV_CTRL_ENB; 527 528 device_writel(dev, val, ACTMON_DEV_CTRL); 529 } 530 531 static void tegra_actmon_stop_devices(struct tegra_devfreq *tegra) 532 { 533 struct tegra_devfreq_device *dev = tegra->devices; 534 unsigned int i; 535 536 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++, dev++) { 537 device_writel(dev, ACTMON_DEV_CTRL_STOP, ACTMON_DEV_CTRL); 538 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, 539 ACTMON_DEV_INTR_STATUS); 540 } 541 } 542 543 static int tegra_actmon_resume(struct tegra_devfreq *tegra) 544 { 545 unsigned int i; 546 int err; 547 548 if (!tegra->devfreq->profile->polling_ms || !tegra->started) 549 return 0; 550 551 actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1, 552 ACTMON_GLB_PERIOD_CTRL); 553 554 /* 555 * CLK notifications are needed in order to reconfigure the upper 556 * consecutive watermark in accordance to the actual clock rate 557 * to avoid unnecessary upper interrupts. 558 */ 559 err = clk_notifier_register(tegra->emc_clock, 560 &tegra->clk_rate_change_nb); 561 if (err) { 562 dev_err(tegra->devfreq->dev.parent, 563 "Failed to register rate change notifier\n"); 564 return err; 565 } 566 567 tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ; 568 569 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) 570 tegra_actmon_configure_device(tegra, &tegra->devices[i]); 571 572 /* 573 * We are estimating CPU's memory bandwidth requirement based on 574 * amount of memory accesses and system's load, judging by CPU's 575 * frequency. We also don't want to receive events about CPU's 576 * frequency transaction when governor is stopped, hence notifier 577 * is registered dynamically. 578 */ 579 err = cpufreq_register_notifier(&tegra->cpu_rate_change_nb, 580 CPUFREQ_TRANSITION_NOTIFIER); 581 if (err) { 582 dev_err(tegra->devfreq->dev.parent, 583 "Failed to register rate change notifier: %d\n", err); 584 goto err_stop; 585 } 586 587 enable_irq(tegra->irq); 588 589 return 0; 590 591 err_stop: 592 tegra_actmon_stop_devices(tegra); 593 594 clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); 595 596 return err; 597 } 598 599 static int tegra_actmon_start(struct tegra_devfreq *tegra) 600 { 601 int ret = 0; 602 603 if (!tegra->started) { 604 tegra->started = true; 605 606 ret = tegra_actmon_resume(tegra); 607 if (ret) 608 tegra->started = false; 609 } 610 611 return ret; 612 } 613 614 static void tegra_actmon_pause(struct tegra_devfreq *tegra) 615 { 616 if (!tegra->devfreq->profile->polling_ms || !tegra->started) 617 return; 618 619 disable_irq(tegra->irq); 620 621 cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb, 622 CPUFREQ_TRANSITION_NOTIFIER); 623 624 cancel_delayed_work_sync(&tegra->cpufreq_update_work); 625 626 tegra_actmon_stop_devices(tegra); 627 628 clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); 629 } 630 631 static void tegra_actmon_stop(struct tegra_devfreq *tegra) 632 { 633 tegra_actmon_pause(tegra); 634 tegra->started = false; 635 } 636 637 static int tegra_devfreq_target(struct device *dev, unsigned long *freq, 638 u32 flags) 639 { 640 struct dev_pm_opp *opp; 641 int ret; 642 643 opp = devfreq_recommended_opp(dev, freq, flags); 644 if (IS_ERR(opp)) { 645 dev_err(dev, "Failed to find opp for %lu Hz\n", *freq); 646 return PTR_ERR(opp); 647 } 648 649 ret = dev_pm_opp_set_opp(dev, opp); 650 dev_pm_opp_put(opp); 651 652 return ret; 653 } 654 655 static int tegra_devfreq_get_dev_status(struct device *dev, 656 struct devfreq_dev_status *stat) 657 { 658 struct tegra_devfreq *tegra = dev_get_drvdata(dev); 659 struct tegra_devfreq_device *actmon_dev; 660 unsigned long cur_freq; 661 662 cur_freq = READ_ONCE(tegra->cur_freq); 663 664 /* To be used by the tegra governor */ 665 stat->private_data = tegra; 666 667 /* The below are to be used by the other governors */ 668 stat->current_frequency = cur_freq * KHZ; 669 670 actmon_dev = &tegra->devices[MCALL]; 671 672 /* Number of cycles spent on memory access */ 673 stat->busy_time = device_readl(actmon_dev, ACTMON_DEV_AVG_COUNT); 674 675 /* The bus can be considered to be saturated way before 100% */ 676 stat->busy_time *= 100 / BUS_SATURATION_RATIO; 677 678 /* Number of cycles in a sampling period */ 679 stat->total_time = tegra->devfreq->profile->polling_ms * cur_freq; 680 681 stat->busy_time = min(stat->busy_time, stat->total_time); 682 683 return 0; 684 } 685 686 static struct devfreq_dev_profile tegra_devfreq_profile = { 687 .polling_ms = ACTMON_SAMPLING_PERIOD, 688 .target = tegra_devfreq_target, 689 .get_dev_status = tegra_devfreq_get_dev_status, 690 .is_cooling_device = true, 691 }; 692 693 static int tegra_governor_get_target(struct devfreq *devfreq, 694 unsigned long *freq) 695 { 696 struct devfreq_dev_status *stat; 697 struct tegra_devfreq *tegra; 698 struct tegra_devfreq_device *dev; 699 unsigned long target_freq = 0; 700 unsigned int i; 701 int err; 702 703 err = devfreq_update_stats(devfreq); 704 if (err) 705 return err; 706 707 stat = &devfreq->last_status; 708 709 tegra = stat->private_data; 710 711 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 712 dev = &tegra->devices[i]; 713 714 actmon_update_target(tegra, dev); 715 716 target_freq = max(target_freq, dev->target_freq); 717 } 718 719 /* 720 * tegra-devfreq driver operates with KHz units, while OPP table 721 * entries use Hz units. Hence we need to convert the units for the 722 * devfreq core. 723 */ 724 *freq = target_freq * KHZ; 725 726 return 0; 727 } 728 729 static int tegra_governor_event_handler(struct devfreq *devfreq, 730 unsigned int event, void *data) 731 { 732 struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent); 733 unsigned int *new_delay = data; 734 int ret = 0; 735 736 /* 737 * Couple devfreq-device with the governor early because it is 738 * needed at the moment of governor's start (used by ISR). 739 */ 740 tegra->devfreq = devfreq; 741 742 switch (event) { 743 case DEVFREQ_GOV_START: 744 devfreq_monitor_start(devfreq); 745 ret = tegra_actmon_start(tegra); 746 break; 747 748 case DEVFREQ_GOV_STOP: 749 tegra_actmon_stop(tegra); 750 devfreq_monitor_stop(devfreq); 751 break; 752 753 case DEVFREQ_GOV_UPDATE_INTERVAL: 754 /* 755 * ACTMON hardware supports up to 256 milliseconds for the 756 * sampling period. 757 */ 758 if (*new_delay > 256) { 759 ret = -EINVAL; 760 break; 761 } 762 763 tegra_actmon_pause(tegra); 764 devfreq_update_interval(devfreq, new_delay); 765 ret = tegra_actmon_resume(tegra); 766 break; 767 768 case DEVFREQ_GOV_SUSPEND: 769 tegra_actmon_stop(tegra); 770 devfreq_monitor_suspend(devfreq); 771 break; 772 773 case DEVFREQ_GOV_RESUME: 774 devfreq_monitor_resume(devfreq); 775 ret = tegra_actmon_start(tegra); 776 break; 777 } 778 779 return ret; 780 } 781 782 static struct devfreq_governor tegra_devfreq_governor = { 783 .name = "tegra_actmon", 784 .attrs = DEVFREQ_GOV_ATTR_POLLING_INTERVAL, 785 .flags = DEVFREQ_GOV_FLAG_IMMUTABLE 786 | DEVFREQ_GOV_FLAG_IRQ_DRIVEN, 787 .get_target_freq = tegra_governor_get_target, 788 .event_handler = tegra_governor_event_handler, 789 }; 790 791 static void devm_tegra_devfreq_deinit_hw(void *data) 792 { 793 struct tegra_devfreq *tegra = data; 794 795 reset_control_reset(tegra->reset); 796 clk_disable_unprepare(tegra->clock); 797 } 798 799 static int devm_tegra_devfreq_init_hw(struct device *dev, 800 struct tegra_devfreq *tegra) 801 { 802 int err; 803 804 err = clk_prepare_enable(tegra->clock); 805 if (err) { 806 dev_err(dev, "Failed to prepare and enable ACTMON clock\n"); 807 return err; 808 } 809 810 err = devm_add_action_or_reset(dev, devm_tegra_devfreq_deinit_hw, 811 tegra); 812 if (err) 813 return err; 814 815 err = reset_control_reset(tegra->reset); 816 if (err) { 817 dev_err(dev, "Failed to reset hardware: %d\n", err); 818 return err; 819 } 820 821 return err; 822 } 823 824 static int tegra_devfreq_config_clks_nop(struct device *dev, 825 struct opp_table *opp_table, 826 struct dev_pm_opp *opp, void *data, 827 bool scaling_down) 828 { 829 /* We want to skip clk configuration via dev_pm_opp_set_opp() */ 830 return 0; 831 } 832 833 static int tegra_devfreq_probe(struct platform_device *pdev) 834 { 835 u32 hw_version = BIT(tegra_sku_info.soc_speedo_id); 836 struct tegra_devfreq_device *dev; 837 struct tegra_devfreq *tegra; 838 struct devfreq *devfreq; 839 unsigned int i; 840 long rate; 841 int err; 842 const char *clk_names[] = { "actmon", NULL }; 843 struct dev_pm_opp_config config = { 844 .supported_hw = &hw_version, 845 .supported_hw_count = 1, 846 .clk_names = clk_names, 847 .config_clks = tegra_devfreq_config_clks_nop, 848 }; 849 850 tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL); 851 if (!tegra) 852 return -ENOMEM; 853 854 tegra->soc = of_device_get_match_data(&pdev->dev); 855 856 tegra->regs = devm_platform_ioremap_resource(pdev, 0); 857 if (IS_ERR(tegra->regs)) 858 return PTR_ERR(tegra->regs); 859 860 tegra->reset = devm_reset_control_get(&pdev->dev, "actmon"); 861 if (IS_ERR(tegra->reset)) { 862 dev_err(&pdev->dev, "Failed to get reset\n"); 863 return PTR_ERR(tegra->reset); 864 } 865 866 tegra->clock = devm_clk_get(&pdev->dev, "actmon"); 867 if (IS_ERR(tegra->clock)) { 868 dev_err(&pdev->dev, "Failed to get actmon clock\n"); 869 return PTR_ERR(tegra->clock); 870 } 871 872 tegra->emc_clock = devm_clk_get(&pdev->dev, "emc"); 873 if (IS_ERR(tegra->emc_clock)) 874 return dev_err_probe(&pdev->dev, PTR_ERR(tegra->emc_clock), 875 "Failed to get emc clock\n"); 876 877 err = platform_get_irq(pdev, 0); 878 if (err < 0) 879 return err; 880 881 tegra->irq = err; 882 883 irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN); 884 885 err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL, 886 actmon_thread_isr, IRQF_ONESHOT, 887 "tegra-devfreq", tegra); 888 if (err) { 889 dev_err(&pdev->dev, "Interrupt request failed: %d\n", err); 890 return err; 891 } 892 893 err = devm_pm_opp_set_config(&pdev->dev, &config); 894 if (err) { 895 dev_err(&pdev->dev, "Failed to set OPP config: %d\n", err); 896 return err; 897 } 898 899 err = devm_pm_opp_of_add_table_indexed(&pdev->dev, 0); 900 if (err) { 901 dev_err(&pdev->dev, "Failed to add OPP table: %d\n", err); 902 return err; 903 } 904 905 err = devm_tegra_devfreq_init_hw(&pdev->dev, tegra); 906 if (err) 907 return err; 908 909 rate = clk_round_rate(tegra->emc_clock, ULONG_MAX); 910 if (rate <= 0) { 911 dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate); 912 return rate ?: -EINVAL; 913 } 914 915 tegra->max_freq = rate / KHZ; 916 917 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 918 dev = tegra->devices + i; 919 dev->config = tegra->soc->configs + i; 920 dev->regs = tegra->regs + dev->config->offset; 921 } 922 923 platform_set_drvdata(pdev, tegra); 924 925 tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb; 926 tegra->cpu_rate_change_nb.notifier_call = tegra_actmon_cpu_notify_cb; 927 928 INIT_DELAYED_WORK(&tegra->cpufreq_update_work, 929 tegra_actmon_delayed_update); 930 931 err = devm_devfreq_add_governor(&pdev->dev, &tegra_devfreq_governor); 932 if (err) { 933 dev_err(&pdev->dev, "Failed to add governor: %d\n", err); 934 return err; 935 } 936 937 tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock); 938 939 devfreq = devm_devfreq_add_device(&pdev->dev, &tegra_devfreq_profile, 940 "tegra_actmon", NULL); 941 if (IS_ERR(devfreq)) { 942 dev_err(&pdev->dev, "Failed to add device: %pe\n", devfreq); 943 return PTR_ERR(devfreq); 944 } 945 946 return 0; 947 } 948 949 static const struct tegra_devfreq_soc_data tegra124_soc = { 950 .configs = tegra124_device_configs, 951 952 /* 953 * Activity counter is incremented every 256 memory transactions, 954 * and each transaction takes 4 EMC clocks. 955 */ 956 .count_weight = 4 * 256, 957 }; 958 959 static const struct tegra_devfreq_soc_data tegra30_soc = { 960 .configs = tegra30_device_configs, 961 .count_weight = 2 * 256, 962 }; 963 964 static const struct of_device_id tegra_devfreq_of_match[] = { 965 { .compatible = "nvidia,tegra30-actmon", .data = &tegra30_soc, }, 966 { .compatible = "nvidia,tegra124-actmon", .data = &tegra124_soc, }, 967 { }, 968 }; 969 970 MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match); 971 972 static struct platform_driver tegra_devfreq_driver = { 973 .probe = tegra_devfreq_probe, 974 .driver = { 975 .name = "tegra-devfreq", 976 .of_match_table = tegra_devfreq_of_match, 977 }, 978 }; 979 module_platform_driver(tegra_devfreq_driver); 980 981 MODULE_LICENSE("GPL v2"); 982 MODULE_DESCRIPTION("Tegra devfreq driver"); 983 MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>"); 984