1/* 2 * A devfreq driver for NVIDIA Tegra SoCs 3 * 4 * Copyright (c) 2014 NVIDIA CORPORATION. All rights reserved. 5 * Copyright (C) 2014 Google, Inc 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 * 19 */ 20 21#include <linux/clk.h> 22#include <linux/cpufreq.h> 23#include <linux/devfreq.h> 24#include <linux/interrupt.h> 25#include <linux/io.h> 26#include <linux/module.h> 27#include <linux/platform_device.h> 28#include <linux/pm_opp.h> 29#include <linux/reset.h> 30 31#include "governor.h" 32 33#define ACTMON_GLB_STATUS 0x0 34#define ACTMON_GLB_PERIOD_CTRL 0x4 35 36#define ACTMON_DEV_CTRL 0x0 37#define ACTMON_DEV_CTRL_K_VAL_SHIFT 10 38#define ACTMON_DEV_CTRL_ENB_PERIODIC BIT(18) 39#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN BIT(20) 40#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN BIT(21) 41#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT 23 42#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT 26 43#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN BIT(29) 44#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN BIT(30) 45#define ACTMON_DEV_CTRL_ENB BIT(31) 46 47#define ACTMON_DEV_UPPER_WMARK 0x4 48#define ACTMON_DEV_LOWER_WMARK 0x8 49#define ACTMON_DEV_INIT_AVG 0xc 50#define ACTMON_DEV_AVG_UPPER_WMARK 0x10 51#define ACTMON_DEV_AVG_LOWER_WMARK 0x14 52#define ACTMON_DEV_COUNT_WEIGHT 0x18 53#define ACTMON_DEV_AVG_COUNT 0x20 54#define ACTMON_DEV_INTR_STATUS 0x24 55 56#define ACTMON_INTR_STATUS_CLEAR 0xffffffff 57 58#define ACTMON_DEV_INTR_CONSECUTIVE_UPPER BIT(31) 59#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER BIT(30) 60 61#define ACTMON_ABOVE_WMARK_WINDOW 1 62#define ACTMON_BELOW_WMARK_WINDOW 3 63#define ACTMON_BOOST_FREQ_STEP 16000 64 65/* 66 * Activity counter is incremented every 256 memory transactions, and each 67 * transaction takes 4 EMC clocks for Tegra124; So the COUNT_WEIGHT is 68 * 4 * 256 = 1024. 69 */ 70#define ACTMON_COUNT_WEIGHT 0x400 71 72/* 73 * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which 74 * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128 75 */ 76#define ACTMON_AVERAGE_WINDOW_LOG2 6 77#define ACTMON_SAMPLING_PERIOD 12 /* ms */ 78#define ACTMON_DEFAULT_AVG_BAND 6 /* 1/10 of % */ 79 80#define KHZ 1000 81 82/* Assume that the bus is saturated if the utilization is 25% */ 83#define BUS_SATURATION_RATIO 25 84 85/** 86 * struct tegra_devfreq_device_config - configuration specific to an ACTMON 87 * device 88 * 89 * Coefficients and thresholds are percentages unless otherwise noted 90 */ 91struct tegra_devfreq_device_config { 92 u32 offset; 93 u32 irq_mask; 94 95 /* Factors applied to boost_freq every consecutive watermark breach */ 96 unsigned int boost_up_coeff; 97 unsigned int boost_down_coeff; 98 99 /* Define the watermark bounds when applied to the current avg */ 100 unsigned int boost_up_threshold; 101 unsigned int boost_down_threshold; 102 103 /* 104 * Threshold of activity (cycles) below which the CPU frequency isn't 105 * to be taken into account. This is to avoid increasing the EMC 106 * frequency when the CPU is very busy but not accessing the bus often. 107 */ 108 u32 avg_dependency_threshold; 109}; 110 111enum tegra_actmon_device { 112 MCALL = 0, 113 MCCPU, 114}; 115 116static struct tegra_devfreq_device_config actmon_device_configs[] = { 117 { 118 /* MCALL: All memory accesses (including from the CPUs) */ 119 .offset = 0x1c0, 120 .irq_mask = 1 << 26, 121 .boost_up_coeff = 200, 122 .boost_down_coeff = 50, 123 .boost_up_threshold = 60, 124 .boost_down_threshold = 40, 125 }, 126 { 127 /* MCCPU: memory accesses from the CPUs */ 128 .offset = 0x200, 129 .irq_mask = 1 << 25, 130 .boost_up_coeff = 800, 131 .boost_down_coeff = 90, 132 .boost_up_threshold = 27, 133 .boost_down_threshold = 10, 134 .avg_dependency_threshold = 50000, 135 }, 136}; 137 138/** 139 * struct tegra_devfreq_device - state specific to an ACTMON device 140 * 141 * Frequencies are in kHz. 142 */ 143struct tegra_devfreq_device { 144 const struct tegra_devfreq_device_config *config; 145 void __iomem *regs; 146 spinlock_t lock; 147 148 /* Average event count sampled in the last interrupt */ 149 u32 avg_count; 150 151 /* 152 * Extra frequency to increase the target by due to consecutive 153 * watermark breaches. 154 */ 155 unsigned long boost_freq; 156 157 /* Optimal frequency calculated from the stats for this device */ 158 unsigned long target_freq; 159}; 160 161struct tegra_devfreq { 162 struct devfreq *devfreq; 163 164 struct reset_control *reset; 165 struct clk *clock; 166 void __iomem *regs; 167 168 struct clk *emc_clock; 169 unsigned long max_freq; 170 unsigned long cur_freq; 171 struct notifier_block rate_change_nb; 172 173 struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)]; 174}; 175 176struct tegra_actmon_emc_ratio { 177 unsigned long cpu_freq; 178 unsigned long emc_freq; 179}; 180 181static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = { 182 { 1400000, ULONG_MAX }, 183 { 1200000, 750000 }, 184 { 1100000, 600000 }, 185 { 1000000, 500000 }, 186 { 800000, 375000 }, 187 { 500000, 200000 }, 188 { 250000, 100000 }, 189}; 190 191static u32 actmon_readl(struct tegra_devfreq *tegra, u32 offset) 192{ 193 return readl(tegra->regs + offset); 194} 195 196static void actmon_writel(struct tegra_devfreq *tegra, u32 val, u32 offset) 197{ 198 writel(val, tegra->regs + offset); 199} 200 201static u32 device_readl(struct tegra_devfreq_device *dev, u32 offset) 202{ 203 return readl(dev->regs + offset); 204} 205 206static void device_writel(struct tegra_devfreq_device *dev, u32 val, 207 u32 offset) 208{ 209 writel(val, dev->regs + offset); 210} 211 212static unsigned long do_percent(unsigned long val, unsigned int pct) 213{ 214 return val * pct / 100; 215} 216 217static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, 218 struct tegra_devfreq_device *dev) 219{ 220 u32 avg = dev->avg_count; 221 u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ; 222 u32 band = avg_band_freq * ACTMON_SAMPLING_PERIOD; 223 224 device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK); 225 226 avg = max(dev->avg_count, band); 227 device_writel(dev, avg - band, ACTMON_DEV_AVG_LOWER_WMARK); 228} 229 230static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra, 231 struct tegra_devfreq_device *dev) 232{ 233 u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD; 234 235 device_writel(dev, do_percent(val, dev->config->boost_up_threshold), 236 ACTMON_DEV_UPPER_WMARK); 237 238 device_writel(dev, do_percent(val, dev->config->boost_down_threshold), 239 ACTMON_DEV_LOWER_WMARK); 240} 241 242static void actmon_write_barrier(struct tegra_devfreq *tegra) 243{ 244 /* ensure the update has reached the ACTMON */ 245 wmb(); 246 actmon_readl(tegra, ACTMON_GLB_STATUS); 247} 248 249static void actmon_isr_device(struct tegra_devfreq *tegra, 250 struct tegra_devfreq_device *dev) 251{ 252 unsigned long flags; 253 u32 intr_status, dev_ctrl; 254 255 spin_lock_irqsave(&dev->lock, flags); 256 257 dev->avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); 258 tegra_devfreq_update_avg_wmark(tegra, dev); 259 260 intr_status = device_readl(dev, ACTMON_DEV_INTR_STATUS); 261 dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL); 262 263 if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) { 264 /* 265 * new_boost = min(old_boost * up_coef + step, max_freq) 266 */ 267 dev->boost_freq = do_percent(dev->boost_freq, 268 dev->config->boost_up_coeff); 269 dev->boost_freq += ACTMON_BOOST_FREQ_STEP; 270 271 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 272 273 if (dev->boost_freq >= tegra->max_freq) 274 dev->boost_freq = tegra->max_freq; 275 else 276 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 277 } else if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) { 278 /* 279 * new_boost = old_boost * down_coef 280 * or 0 if (old_boost * down_coef < step / 2) 281 */ 282 dev->boost_freq = do_percent(dev->boost_freq, 283 dev->config->boost_down_coeff); 284 285 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 286 287 if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1)) 288 dev->boost_freq = 0; 289 else 290 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 291 } 292 293 if (dev->config->avg_dependency_threshold) { 294 if (dev->avg_count >= dev->config->avg_dependency_threshold) 295 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 296 else if (dev->boost_freq == 0) 297 dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 298 } 299 300 device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL); 301 302 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS); 303 304 actmon_write_barrier(tegra); 305 306 spin_unlock_irqrestore(&dev->lock, flags); 307} 308 309static irqreturn_t actmon_isr(int irq, void *data) 310{ 311 struct tegra_devfreq *tegra = data; 312 bool handled = false; 313 unsigned int i; 314 u32 val; 315 316 val = actmon_readl(tegra, ACTMON_GLB_STATUS); 317 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 318 if (val & tegra->devices[i].config->irq_mask) { 319 actmon_isr_device(tegra, tegra->devices + i); 320 handled = true; 321 } 322 } 323 324 return handled ? IRQ_WAKE_THREAD : IRQ_NONE; 325} 326 327static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra, 328 unsigned long cpu_freq) 329{ 330 unsigned int i; 331 struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios; 332 333 for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) { 334 if (cpu_freq >= ratio->cpu_freq) { 335 if (ratio->emc_freq >= tegra->max_freq) 336 return tegra->max_freq; 337 else 338 return ratio->emc_freq; 339 } 340 } 341 342 return 0; 343} 344 345static void actmon_update_target(struct tegra_devfreq *tegra, 346 struct tegra_devfreq_device *dev) 347{ 348 unsigned long cpu_freq = 0; 349 unsigned long static_cpu_emc_freq = 0; 350 unsigned int avg_sustain_coef; 351 unsigned long flags; 352 353 if (dev->config->avg_dependency_threshold) { 354 cpu_freq = cpufreq_get(0); 355 static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq); 356 } 357 358 spin_lock_irqsave(&dev->lock, flags); 359 360 dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD; 361 avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold; 362 dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef); 363 dev->target_freq += dev->boost_freq; 364 365 if (dev->avg_count >= dev->config->avg_dependency_threshold) 366 dev->target_freq = max(dev->target_freq, static_cpu_emc_freq); 367 368 spin_unlock_irqrestore(&dev->lock, flags); 369} 370 371static irqreturn_t actmon_thread_isr(int irq, void *data) 372{ 373 struct tegra_devfreq *tegra = data; 374 375 mutex_lock(&tegra->devfreq->lock); 376 update_devfreq(tegra->devfreq); 377 mutex_unlock(&tegra->devfreq->lock); 378 379 return IRQ_HANDLED; 380} 381 382static int tegra_actmon_rate_notify_cb(struct notifier_block *nb, 383 unsigned long action, void *ptr) 384{ 385 struct clk_notifier_data *data = ptr; 386 struct tegra_devfreq *tegra; 387 struct tegra_devfreq_device *dev; 388 unsigned int i; 389 unsigned long flags; 390 391 if (action != POST_RATE_CHANGE) 392 return NOTIFY_OK; 393 394 tegra = container_of(nb, struct tegra_devfreq, rate_change_nb); 395 396 tegra->cur_freq = data->new_rate / KHZ; 397 398 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 399 dev = &tegra->devices[i]; 400 401 spin_lock_irqsave(&dev->lock, flags); 402 tegra_devfreq_update_wmark(tegra, dev); 403 spin_unlock_irqrestore(&dev->lock, flags); 404 } 405 406 actmon_write_barrier(tegra); 407 408 return NOTIFY_OK; 409} 410 411static void tegra_actmon_enable_interrupts(struct tegra_devfreq *tegra) 412{ 413 struct tegra_devfreq_device *dev; 414 u32 val; 415 unsigned int i; 416 417 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 418 dev = &tegra->devices[i]; 419 420 val = device_readl(dev, ACTMON_DEV_CTRL); 421 val |= ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN; 422 val |= ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN; 423 val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 424 val |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 425 426 device_writel(dev, val, ACTMON_DEV_CTRL); 427 } 428 429 actmon_write_barrier(tegra); 430} 431 432static void tegra_actmon_disable_interrupts(struct tegra_devfreq *tegra) 433{ 434 struct tegra_devfreq_device *dev; 435 u32 val; 436 unsigned int i; 437 438 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 439 dev = &tegra->devices[i]; 440 441 val = device_readl(dev, ACTMON_DEV_CTRL); 442 val &= ~ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN; 443 val &= ~ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN; 444 val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 445 val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 446 447 device_writel(dev, val, ACTMON_DEV_CTRL); 448 } 449 450 actmon_write_barrier(tegra); 451} 452 453static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, 454 struct tegra_devfreq_device *dev) 455{ 456 u32 val = 0; 457 458 dev->target_freq = tegra->cur_freq; 459 460 dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD; 461 device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG); 462 463 tegra_devfreq_update_avg_wmark(tegra, dev); 464 tegra_devfreq_update_wmark(tegra, dev); 465 466 device_writel(dev, ACTMON_COUNT_WEIGHT, ACTMON_DEV_COUNT_WEIGHT); 467 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS); 468 469 val |= ACTMON_DEV_CTRL_ENB_PERIODIC; 470 val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1) 471 << ACTMON_DEV_CTRL_K_VAL_SHIFT; 472 val |= (ACTMON_BELOW_WMARK_WINDOW - 1) 473 << ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT; 474 val |= (ACTMON_ABOVE_WMARK_WINDOW - 1) 475 << ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT; 476 val |= ACTMON_DEV_CTRL_ENB; 477 478 device_writel(dev, val, ACTMON_DEV_CTRL); 479 480 actmon_write_barrier(tegra); 481} 482 483static int tegra_devfreq_target(struct device *dev, unsigned long *freq, 484 u32 flags) 485{ 486 struct tegra_devfreq *tegra = dev_get_drvdata(dev); 487 struct dev_pm_opp *opp; 488 unsigned long rate = *freq * KHZ; 489 490 rcu_read_lock(); 491 opp = devfreq_recommended_opp(dev, &rate, flags); 492 if (IS_ERR(opp)) { 493 rcu_read_unlock(); 494 dev_err(dev, "Failed to find opp for %lu KHz\n", *freq); 495 return PTR_ERR(opp); 496 } 497 rate = dev_pm_opp_get_freq(opp); 498 rcu_read_unlock(); 499 500 clk_set_min_rate(tegra->emc_clock, rate); 501 clk_set_rate(tegra->emc_clock, 0); 502 503 return 0; 504} 505 506static int tegra_devfreq_get_dev_status(struct device *dev, 507 struct devfreq_dev_status *stat) 508{ 509 struct tegra_devfreq *tegra = dev_get_drvdata(dev); 510 struct tegra_devfreq_device *actmon_dev; 511 512 stat->current_frequency = tegra->cur_freq; 513 514 /* To be used by the tegra governor */ 515 stat->private_data = tegra; 516 517 /* The below are to be used by the other governors */ 518 519 actmon_dev = &tegra->devices[MCALL]; 520 521 /* Number of cycles spent on memory access */ 522 stat->busy_time = device_readl(actmon_dev, ACTMON_DEV_AVG_COUNT); 523 524 /* The bus can be considered to be saturated way before 100% */ 525 stat->busy_time *= 100 / BUS_SATURATION_RATIO; 526 527 /* Number of cycles in a sampling period */ 528 stat->total_time = ACTMON_SAMPLING_PERIOD * tegra->cur_freq; 529 530 stat->busy_time = min(stat->busy_time, stat->total_time); 531 532 return 0; 533} 534 535static struct devfreq_dev_profile tegra_devfreq_profile = { 536 .polling_ms = 0, 537 .target = tegra_devfreq_target, 538 .get_dev_status = tegra_devfreq_get_dev_status, 539}; 540 541static int tegra_governor_get_target(struct devfreq *devfreq, 542 unsigned long *freq) 543{ 544 struct devfreq_dev_status stat; 545 struct tegra_devfreq *tegra; 546 struct tegra_devfreq_device *dev; 547 unsigned long target_freq = 0; 548 unsigned int i; 549 int err; 550 551 err = devfreq->profile->get_dev_status(devfreq->dev.parent, &stat); 552 if (err) 553 return err; 554 555 tegra = stat.private_data; 556 557 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) { 558 dev = &tegra->devices[i]; 559 560 actmon_update_target(tegra, dev); 561 562 target_freq = max(target_freq, dev->target_freq); 563 } 564 565 *freq = target_freq; 566 567 return 0; 568} 569 570static int tegra_governor_event_handler(struct devfreq *devfreq, 571 unsigned int event, void *data) 572{ 573 struct tegra_devfreq *tegra; 574 int ret = 0; 575 576 tegra = dev_get_drvdata(devfreq->dev.parent); 577 578 switch (event) { 579 case DEVFREQ_GOV_START: 580 devfreq_monitor_start(devfreq); 581 tegra_actmon_enable_interrupts(tegra); 582 break; 583 584 case DEVFREQ_GOV_STOP: 585 tegra_actmon_disable_interrupts(tegra); 586 devfreq_monitor_stop(devfreq); 587 break; 588 589 case DEVFREQ_GOV_SUSPEND: 590 tegra_actmon_disable_interrupts(tegra); 591 devfreq_monitor_suspend(devfreq); 592 break; 593 594 case DEVFREQ_GOV_RESUME: 595 devfreq_monitor_resume(devfreq); 596 tegra_actmon_enable_interrupts(tegra); 597 break; 598 } 599 600 return ret; 601} 602 603static struct devfreq_governor tegra_devfreq_governor = { 604 .name = "tegra_actmon", 605 .get_target_freq = tegra_governor_get_target, 606 .event_handler = tegra_governor_event_handler, 607}; 608 609static int tegra_devfreq_probe(struct platform_device *pdev) 610{ 611 struct tegra_devfreq *tegra; 612 struct tegra_devfreq_device *dev; 613 struct resource *res; 614 unsigned int i; 615 unsigned long rate; 616 int irq; 617 int err; 618 619 tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL); 620 if (!tegra) 621 return -ENOMEM; 622 623 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 624 625 tegra->regs = devm_ioremap_resource(&pdev->dev, res); 626 if (IS_ERR(tegra->regs)) 627 return PTR_ERR(tegra->regs); 628 629 tegra->reset = devm_reset_control_get(&pdev->dev, "actmon"); 630 if (IS_ERR(tegra->reset)) { 631 dev_err(&pdev->dev, "Failed to get reset\n"); 632 return PTR_ERR(tegra->reset); 633 } 634 635 tegra->clock = devm_clk_get(&pdev->dev, "actmon"); 636 if (IS_ERR(tegra->clock)) { 637 dev_err(&pdev->dev, "Failed to get actmon clock\n"); 638 return PTR_ERR(tegra->clock); 639 } 640 641 tegra->emc_clock = devm_clk_get(&pdev->dev, "emc"); 642 if (IS_ERR(tegra->emc_clock)) { 643 dev_err(&pdev->dev, "Failed to get emc clock\n"); 644 return PTR_ERR(tegra->emc_clock); 645 } 646 647 clk_set_rate(tegra->emc_clock, ULONG_MAX); 648 649 tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb; 650 err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb); 651 if (err) { 652 dev_err(&pdev->dev, 653 "Failed to register rate change notifier\n"); 654 return err; 655 } 656 657 reset_control_assert(tegra->reset); 658 659 err = clk_prepare_enable(tegra->clock); 660 if (err) { 661 dev_err(&pdev->dev, 662 "Failed to prepare and enable ACTMON clock\n"); 663 return err; 664 } 665 666 reset_control_deassert(tegra->reset); 667 668 tegra->max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX) / KHZ; 669 tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ; 670 671 actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, 672 ACTMON_GLB_PERIOD_CTRL); 673 674 for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) { 675 dev = tegra->devices + i; 676 dev->config = actmon_device_configs + i; 677 dev->regs = tegra->regs + dev->config->offset; 678 spin_lock_init(&dev->lock); 679 680 tegra_actmon_configure_device(tegra, dev); 681 } 682 683 for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) { 684 rate = clk_round_rate(tegra->emc_clock, rate); 685 dev_pm_opp_add(&pdev->dev, rate, 0); 686 } 687 688 irq = platform_get_irq(pdev, 0); 689 if (irq <= 0) { 690 dev_err(&pdev->dev, "Failed to get IRQ\n"); 691 return -ENODEV; 692 } 693 694 platform_set_drvdata(pdev, tegra); 695 696 err = devm_request_threaded_irq(&pdev->dev, irq, actmon_isr, 697 actmon_thread_isr, IRQF_SHARED, 698 "tegra-devfreq", tegra); 699 if (err) { 700 dev_err(&pdev->dev, "Interrupt request failed\n"); 701 return err; 702 } 703 704 tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock); 705 tegra->devfreq = devm_devfreq_add_device(&pdev->dev, 706 &tegra_devfreq_profile, 707 "tegra_actmon", 708 NULL); 709 710 return 0; 711} 712 713static int tegra_devfreq_remove(struct platform_device *pdev) 714{ 715 struct tegra_devfreq *tegra = platform_get_drvdata(pdev); 716 int irq = platform_get_irq(pdev, 0); 717 u32 val; 718 unsigned int i; 719 720 for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) { 721 val = device_readl(&tegra->devices[i], ACTMON_DEV_CTRL); 722 val &= ~ACTMON_DEV_CTRL_ENB; 723 device_writel(&tegra->devices[i], val, ACTMON_DEV_CTRL); 724 } 725 726 actmon_write_barrier(tegra); 727 728 devm_free_irq(&pdev->dev, irq, tegra); 729 730 clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb); 731 732 clk_disable_unprepare(tegra->clock); 733 734 return 0; 735} 736 737static const struct of_device_id tegra_devfreq_of_match[] = { 738 { .compatible = "nvidia,tegra124-actmon" }, 739 { }, 740}; 741 742MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match); 743 744static struct platform_driver tegra_devfreq_driver = { 745 .probe = tegra_devfreq_probe, 746 .remove = tegra_devfreq_remove, 747 .driver = { 748 .name = "tegra-devfreq", 749 .of_match_table = tegra_devfreq_of_match, 750 }, 751}; 752 753static int __init tegra_devfreq_init(void) 754{ 755 int ret = 0; 756 757 ret = devfreq_add_governor(&tegra_devfreq_governor); 758 if (ret) { 759 pr_err("%s: failed to add governor: %d\n", __func__, ret); 760 return ret; 761 } 762 763 ret = platform_driver_register(&tegra_devfreq_driver); 764 if (ret) 765 devfreq_remove_governor(&tegra_devfreq_governor); 766 767 return ret; 768} 769module_init(tegra_devfreq_init) 770 771static void __exit tegra_devfreq_exit(void) 772{ 773 int ret = 0; 774 775 platform_driver_unregister(&tegra_devfreq_driver); 776 777 ret = devfreq_remove_governor(&tegra_devfreq_governor); 778 if (ret) 779 pr_err("%s: failed to remove governor: %d\n", __func__, ret); 780} 781module_exit(tegra_devfreq_exit) 782 783MODULE_LICENSE("GPL v2"); 784MODULE_DESCRIPTION("Tegra devfreq driver"); 785MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>"); 786