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