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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 "governor.h"
23
24#define ACTMON_GLB_STATUS 0x0
25#define ACTMON_GLB_PERIOD_CTRL 0x4
26
27#define ACTMON_DEV_CTRL 0x0
28#define ACTMON_DEV_CTRL_K_VAL_SHIFT 10
29#define ACTMON_DEV_CTRL_ENB_PERIODIC BIT(18)
30#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN BIT(20)
31#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN BIT(21)
32#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT 23
33#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT 26
34#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN BIT(29)
35#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN BIT(30)
36#define ACTMON_DEV_CTRL_ENB BIT(31)
37
38#define ACTMON_DEV_CTRL_STOP 0x00000000
39
40#define ACTMON_DEV_UPPER_WMARK 0x4
41#define ACTMON_DEV_LOWER_WMARK 0x8
42#define ACTMON_DEV_INIT_AVG 0xc
43#define ACTMON_DEV_AVG_UPPER_WMARK 0x10
44#define ACTMON_DEV_AVG_LOWER_WMARK 0x14
45#define ACTMON_DEV_COUNT_WEIGHT 0x18
46#define ACTMON_DEV_AVG_COUNT 0x20
47#define ACTMON_DEV_INTR_STATUS 0x24
48
49#define ACTMON_INTR_STATUS_CLEAR 0xffffffff
50
51#define ACTMON_DEV_INTR_CONSECUTIVE_UPPER BIT(31)
52#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER BIT(30)
53
54#define ACTMON_ABOVE_WMARK_WINDOW 1
55#define ACTMON_BELOW_WMARK_WINDOW 3
56#define ACTMON_BOOST_FREQ_STEP 16000
57
58/*
59 * Activity counter is incremented every 256 memory transactions, and each
60 * transaction takes 4 EMC clocks for Tegra124; So the COUNT_WEIGHT is
61 * 4 * 256 = 1024.
62 */
63#define ACTMON_COUNT_WEIGHT 0x400
64
65/*
66 * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which
67 * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128
68 */
69#define ACTMON_AVERAGE_WINDOW_LOG2 6
70#define ACTMON_SAMPLING_PERIOD 12 /* ms */
71#define ACTMON_DEFAULT_AVG_BAND 6 /* 1/10 of % */
72
73#define KHZ 1000
74
75#define KHZ_MAX (ULONG_MAX / KHZ)
76
77/* Assume that the bus is saturated if the utilization is 25% */
78#define BUS_SATURATION_RATIO 25
79
80/**
81 * struct tegra_devfreq_device_config - configuration specific to an ACTMON
82 * device
83 *
84 * Coefficients and thresholds are percentages unless otherwise noted
85 */
86struct tegra_devfreq_device_config {
87 u32 offset;
88 u32 irq_mask;
89
90 /* Factors applied to boost_freq every consecutive watermark breach */
91 unsigned int boost_up_coeff;
92 unsigned int boost_down_coeff;
93
94 /* Define the watermark bounds when applied to the current avg */
95 unsigned int boost_up_threshold;
96 unsigned int boost_down_threshold;
97
98 /*
99 * Threshold of activity (cycles translated to kHz) below which the
100 * CPU frequency isn't to be taken into account. This is to avoid
101 * increasing the EMC frequency when the CPU is very busy but not
102 * accessing the bus often.
103 */
104 u32 avg_dependency_threshold;
105};
106
107enum tegra_actmon_device {
108 MCALL = 0,
109 MCCPU,
110};
111
112static const struct tegra_devfreq_device_config actmon_device_configs[] = {
113 {
114 /* MCALL: All memory accesses (including from the CPUs) */
115 .offset = 0x1c0,
116 .irq_mask = 1 << 26,
117 .boost_up_coeff = 200,
118 .boost_down_coeff = 50,
119 .boost_up_threshold = 60,
120 .boost_down_threshold = 40,
121 },
122 {
123 /* MCCPU: memory accesses from the CPUs */
124 .offset = 0x200,
125 .irq_mask = 1 << 25,
126 .boost_up_coeff = 800,
127 .boost_down_coeff = 40,
128 .boost_up_threshold = 27,
129 .boost_down_threshold = 10,
130 .avg_dependency_threshold = 16000, /* 16MHz in kHz units */
131 },
132};
133
134/**
135 * struct tegra_devfreq_device - state specific to an ACTMON device
136 *
137 * Frequencies are in kHz.
138 */
139struct tegra_devfreq_device {
140 const struct tegra_devfreq_device_config *config;
141 void __iomem *regs;
142
143 /* Average event count sampled in the last interrupt */
144 u32 avg_count;
145
146 /*
147 * Extra frequency to increase the target by due to consecutive
148 * watermark breaches.
149 */
150 unsigned long boost_freq;
151
152 /* Optimal frequency calculated from the stats for this device */
153 unsigned long target_freq;
154};
155
156struct tegra_devfreq {
157 struct devfreq *devfreq;
158
159 struct reset_control *reset;
160 struct clk *clock;
161 void __iomem *regs;
162
163 struct clk *emc_clock;
164 unsigned long max_freq;
165 unsigned long cur_freq;
166 struct notifier_block clk_rate_change_nb;
167
168 struct delayed_work cpufreq_update_work;
169 struct notifier_block cpu_rate_change_nb;
170
171 struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];
172
173 unsigned int irq;
174
175 bool started;
176};
177
178struct tegra_actmon_emc_ratio {
179 unsigned long cpu_freq;
180 unsigned long emc_freq;
181};
182
183static const struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
184 { 1400000, KHZ_MAX },
185 { 1200000, 750000 },
186 { 1100000, 600000 },
187 { 1000000, 500000 },
188 { 800000, 375000 },
189 { 500000, 200000 },
190 { 250000, 100000 },
191};
192
193static u32 actmon_readl(struct tegra_devfreq *tegra, u32 offset)
194{
195 return readl_relaxed(tegra->regs + offset);
196}
197
198static void actmon_writel(struct tegra_devfreq *tegra, u32 val, u32 offset)
199{
200 writel_relaxed(val, tegra->regs + offset);
201}
202
203static u32 device_readl(struct tegra_devfreq_device *dev, u32 offset)
204{
205 return readl_relaxed(dev->regs + offset);
206}
207
208static void device_writel(struct tegra_devfreq_device *dev, u32 val,
209 u32 offset)
210{
211 writel_relaxed(val, dev->regs + offset);
212}
213
214static unsigned long do_percent(unsigned long long val, unsigned int pct)
215{
216 val = val * pct;
217 do_div(val, 100);
218
219 /*
220 * High freq + high boosting percent + large polling interval are
221 * resulting in integer overflow when watermarks are calculated.
222 */
223 return min_t(u64, val, U32_MAX);
224}
225
226static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra,
227 struct tegra_devfreq_device *dev)
228{
229 u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;
230 u32 band = avg_band_freq * tegra->devfreq->profile->polling_ms;
231 u32 avg;
232
233 avg = min(dev->avg_count, U32_MAX - band);
234 device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK);
235
236 avg = max(dev->avg_count, band);
237 device_writel(dev, avg - band, ACTMON_DEV_AVG_LOWER_WMARK);
238}
239
240static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,
241 struct tegra_devfreq_device *dev)
242{
243 u32 val = tegra->cur_freq * tegra->devfreq->profile->polling_ms;
244
245 device_writel(dev, do_percent(val, dev->config->boost_up_threshold),
246 ACTMON_DEV_UPPER_WMARK);
247
248 device_writel(dev, do_percent(val, dev->config->boost_down_threshold),
249 ACTMON_DEV_LOWER_WMARK);
250}
251
252static void actmon_isr_device(struct tegra_devfreq *tegra,
253 struct tegra_devfreq_device *dev)
254{
255 u32 intr_status, dev_ctrl;
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_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
275 dev->boost_freq = tegra->max_freq;
276 }
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_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
289 dev->boost_freq = 0;
290 }
291 }
292
293 device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL);
294
295 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
296}
297
298static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
299 unsigned long cpu_freq)
300{
301 unsigned int i;
302 const struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
303
304 for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {
305 if (cpu_freq >= ratio->cpu_freq) {
306 if (ratio->emc_freq >= tegra->max_freq)
307 return tegra->max_freq;
308 else
309 return ratio->emc_freq;
310 }
311 }
312
313 return 0;
314}
315
316static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra,
317 struct tegra_devfreq_device *dev)
318{
319 unsigned int avg_sustain_coef;
320 unsigned long target_freq;
321
322 target_freq = dev->avg_count / tegra->devfreq->profile->polling_ms;
323 avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
324 target_freq = do_percent(target_freq, avg_sustain_coef);
325
326 return target_freq;
327}
328
329static void actmon_update_target(struct tegra_devfreq *tegra,
330 struct tegra_devfreq_device *dev)
331{
332 unsigned long cpu_freq = 0;
333 unsigned long static_cpu_emc_freq = 0;
334
335 dev->target_freq = actmon_device_target_freq(tegra, dev);
336
337 if (dev->config->avg_dependency_threshold &&
338 dev->config->avg_dependency_threshold <= dev->target_freq) {
339 cpu_freq = cpufreq_quick_get(0);
340 static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
341
342 dev->target_freq += dev->boost_freq;
343 dev->target_freq = max(dev->target_freq, static_cpu_emc_freq);
344 } else {
345 dev->target_freq += dev->boost_freq;
346 }
347}
348
349static irqreturn_t actmon_thread_isr(int irq, void *data)
350{
351 struct tegra_devfreq *tegra = data;
352 bool handled = false;
353 unsigned int i;
354 u32 val;
355
356 mutex_lock(&tegra->devfreq->lock);
357
358 val = actmon_readl(tegra, ACTMON_GLB_STATUS);
359 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
360 if (val & tegra->devices[i].config->irq_mask) {
361 actmon_isr_device(tegra, tegra->devices + i);
362 handled = true;
363 }
364 }
365
366 if (handled)
367 update_devfreq(tegra->devfreq);
368
369 mutex_unlock(&tegra->devfreq->lock);
370
371 return handled ? IRQ_HANDLED : IRQ_NONE;
372}
373
374static int tegra_actmon_clk_notify_cb(struct notifier_block *nb,
375 unsigned long action, void *ptr)
376{
377 struct clk_notifier_data *data = ptr;
378 struct tegra_devfreq *tegra;
379 struct tegra_devfreq_device *dev;
380 unsigned int i;
381
382 if (action != POST_RATE_CHANGE)
383 return NOTIFY_OK;
384
385 tegra = container_of(nb, struct tegra_devfreq, clk_rate_change_nb);
386
387 tegra->cur_freq = data->new_rate / KHZ;
388
389 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
390 dev = &tegra->devices[i];
391
392 tegra_devfreq_update_wmark(tegra, dev);
393 }
394
395 return NOTIFY_OK;
396}
397
398static void tegra_actmon_delayed_update(struct work_struct *work)
399{
400 struct tegra_devfreq *tegra = container_of(work, struct tegra_devfreq,
401 cpufreq_update_work.work);
402
403 mutex_lock(&tegra->devfreq->lock);
404 update_devfreq(tegra->devfreq);
405 mutex_unlock(&tegra->devfreq->lock);
406}
407
408static unsigned long
409tegra_actmon_cpufreq_contribution(struct tegra_devfreq *tegra,
410 unsigned int cpu_freq)
411{
412 struct tegra_devfreq_device *actmon_dev = &tegra->devices[MCCPU];
413 unsigned long static_cpu_emc_freq, dev_freq;
414
415 dev_freq = actmon_device_target_freq(tegra, actmon_dev);
416
417 /* check whether CPU's freq is taken into account at all */
418 if (dev_freq < actmon_dev->config->avg_dependency_threshold)
419 return 0;
420
421 static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
422
423 if (dev_freq + actmon_dev->boost_freq >= static_cpu_emc_freq)
424 return 0;
425
426 return static_cpu_emc_freq;
427}
428
429static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb,
430 unsigned long action, void *ptr)
431{
432 struct cpufreq_freqs *freqs = ptr;
433 struct tegra_devfreq *tegra;
434 unsigned long old, new, delay;
435
436 if (action != CPUFREQ_POSTCHANGE)
437 return NOTIFY_OK;
438
439 tegra = container_of(nb, struct tegra_devfreq, cpu_rate_change_nb);
440
441 /*
442 * Quickly check whether CPU frequency should be taken into account
443 * at all, without blocking CPUFreq's core.
444 */
445 if (mutex_trylock(&tegra->devfreq->lock)) {
446 old = tegra_actmon_cpufreq_contribution(tegra, freqs->old);
447 new = tegra_actmon_cpufreq_contribution(tegra, freqs->new);
448 mutex_unlock(&tegra->devfreq->lock);
449
450 /*
451 * If CPU's frequency shouldn't be taken into account at
452 * the moment, then there is no need to update the devfreq's
453 * state because ISR will re-check CPU's frequency on the
454 * next interrupt.
455 */
456 if (old == new)
457 return NOTIFY_OK;
458 }
459
460 /*
461 * CPUFreq driver should support CPUFREQ_ASYNC_NOTIFICATION in order
462 * to allow asynchronous notifications. This means we can't block
463 * here for too long, otherwise CPUFreq's core will complain with a
464 * warning splat.
465 */
466 delay = msecs_to_jiffies(ACTMON_SAMPLING_PERIOD);
467 schedule_delayed_work(&tegra->cpufreq_update_work, delay);
468
469 return NOTIFY_OK;
470}
471
472static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
473 struct tegra_devfreq_device *dev)
474{
475 u32 val = 0;
476
477 /* reset boosting on governor's restart */
478 dev->boost_freq = 0;
479
480 dev->target_freq = tegra->cur_freq;
481
482 dev->avg_count = tegra->cur_freq * tegra->devfreq->profile->polling_ms;
483 device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG);
484
485 tegra_devfreq_update_avg_wmark(tegra, dev);
486 tegra_devfreq_update_wmark(tegra, dev);
487
488 device_writel(dev, ACTMON_COUNT_WEIGHT, ACTMON_DEV_COUNT_WEIGHT);
489 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
490
491 val |= ACTMON_DEV_CTRL_ENB_PERIODIC;
492 val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1)
493 << ACTMON_DEV_CTRL_K_VAL_SHIFT;
494 val |= (ACTMON_BELOW_WMARK_WINDOW - 1)
495 << ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT;
496 val |= (ACTMON_ABOVE_WMARK_WINDOW - 1)
497 << ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT;
498 val |= ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN;
499 val |= ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;
500 val |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
501 val |= ACTMON_DEV_CTRL_ENB;
502
503 device_writel(dev, val, ACTMON_DEV_CTRL);
504}
505
506static void tegra_actmon_stop_devices(struct tegra_devfreq *tegra)
507{
508 struct tegra_devfreq_device *dev = tegra->devices;
509 unsigned int i;
510
511 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++, dev++) {
512 device_writel(dev, ACTMON_DEV_CTRL_STOP, ACTMON_DEV_CTRL);
513 device_writel(dev, ACTMON_INTR_STATUS_CLEAR,
514 ACTMON_DEV_INTR_STATUS);
515 }
516}
517
518static int tegra_actmon_resume(struct tegra_devfreq *tegra)
519{
520 unsigned int i;
521 int err;
522
523 if (!tegra->devfreq->profile->polling_ms || !tegra->started)
524 return 0;
525
526 actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1,
527 ACTMON_GLB_PERIOD_CTRL);
528
529 /*
530 * CLK notifications are needed in order to reconfigure the upper
531 * consecutive watermark in accordance to the actual clock rate
532 * to avoid unnecessary upper interrupts.
533 */
534 err = clk_notifier_register(tegra->emc_clock,
535 &tegra->clk_rate_change_nb);
536 if (err) {
537 dev_err(tegra->devfreq->dev.parent,
538 "Failed to register rate change notifier\n");
539 return err;
540 }
541
542 tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
543
544 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++)
545 tegra_actmon_configure_device(tegra, &tegra->devices[i]);
546
547 /*
548 * We are estimating CPU's memory bandwidth requirement based on
549 * amount of memory accesses and system's load, judging by CPU's
550 * frequency. We also don't want to receive events about CPU's
551 * frequency transaction when governor is stopped, hence notifier
552 * is registered dynamically.
553 */
554 err = cpufreq_register_notifier(&tegra->cpu_rate_change_nb,
555 CPUFREQ_TRANSITION_NOTIFIER);
556 if (err) {
557 dev_err(tegra->devfreq->dev.parent,
558 "Failed to register rate change notifier: %d\n", err);
559 goto err_stop;
560 }
561
562 enable_irq(tegra->irq);
563
564 return 0;
565
566err_stop:
567 tegra_actmon_stop_devices(tegra);
568
569 clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb);
570
571 return err;
572}
573
574static int tegra_actmon_start(struct tegra_devfreq *tegra)
575{
576 int ret = 0;
577
578 if (!tegra->started) {
579 tegra->started = true;
580
581 ret = tegra_actmon_resume(tegra);
582 if (ret)
583 tegra->started = false;
584 }
585
586 return ret;
587}
588
589static void tegra_actmon_pause(struct tegra_devfreq *tegra)
590{
591 if (!tegra->devfreq->profile->polling_ms || !tegra->started)
592 return;
593
594 disable_irq(tegra->irq);
595
596 cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb,
597 CPUFREQ_TRANSITION_NOTIFIER);
598
599 cancel_delayed_work_sync(&tegra->cpufreq_update_work);
600
601 tegra_actmon_stop_devices(tegra);
602
603 clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb);
604}
605
606static void tegra_actmon_stop(struct tegra_devfreq *tegra)
607{
608 tegra_actmon_pause(tegra);
609 tegra->started = false;
610}
611
612static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
613 u32 flags)
614{
615 struct tegra_devfreq *tegra = dev_get_drvdata(dev);
616 struct devfreq *devfreq = tegra->devfreq;
617 struct dev_pm_opp *opp;
618 unsigned long rate;
619 int err;
620
621 opp = devfreq_recommended_opp(dev, freq, flags);
622 if (IS_ERR(opp)) {
623 dev_err(dev, "Failed to find opp for %lu Hz\n", *freq);
624 return PTR_ERR(opp);
625 }
626 rate = dev_pm_opp_get_freq(opp);
627 dev_pm_opp_put(opp);
628
629 err = clk_set_min_rate(tegra->emc_clock, rate * KHZ);
630 if (err)
631 return err;
632
633 err = clk_set_rate(tegra->emc_clock, 0);
634 if (err)
635 goto restore_min_rate;
636
637 return 0;
638
639restore_min_rate:
640 clk_set_min_rate(tegra->emc_clock, devfreq->previous_freq);
641
642 return err;
643}
644
645static int tegra_devfreq_get_dev_status(struct device *dev,
646 struct devfreq_dev_status *stat)
647{
648 struct tegra_devfreq *tegra = dev_get_drvdata(dev);
649 struct tegra_devfreq_device *actmon_dev;
650 unsigned long cur_freq;
651
652 cur_freq = READ_ONCE(tegra->cur_freq);
653
654 /* To be used by the tegra governor */
655 stat->private_data = tegra;
656
657 /* The below are to be used by the other governors */
658 stat->current_frequency = cur_freq;
659
660 actmon_dev = &tegra->devices[MCALL];
661
662 /* Number of cycles spent on memory access */
663 stat->busy_time = device_readl(actmon_dev, ACTMON_DEV_AVG_COUNT);
664
665 /* The bus can be considered to be saturated way before 100% */
666 stat->busy_time *= 100 / BUS_SATURATION_RATIO;
667
668 /* Number of cycles in a sampling period */
669 stat->total_time = tegra->devfreq->profile->polling_ms * cur_freq;
670
671 stat->busy_time = min(stat->busy_time, stat->total_time);
672
673 return 0;
674}
675
676static struct devfreq_dev_profile tegra_devfreq_profile = {
677 .polling_ms = ACTMON_SAMPLING_PERIOD,
678 .target = tegra_devfreq_target,
679 .get_dev_status = tegra_devfreq_get_dev_status,
680};
681
682static int tegra_governor_get_target(struct devfreq *devfreq,
683 unsigned long *freq)
684{
685 struct devfreq_dev_status *stat;
686 struct tegra_devfreq *tegra;
687 struct tegra_devfreq_device *dev;
688 unsigned long target_freq = 0;
689 unsigned int i;
690 int err;
691
692 err = devfreq_update_stats(devfreq);
693 if (err)
694 return err;
695
696 stat = &devfreq->last_status;
697
698 tegra = stat->private_data;
699
700 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
701 dev = &tegra->devices[i];
702
703 actmon_update_target(tegra, dev);
704
705 target_freq = max(target_freq, dev->target_freq);
706 }
707
708 *freq = target_freq;
709
710 return 0;
711}
712
713static int tegra_governor_event_handler(struct devfreq *devfreq,
714 unsigned int event, void *data)
715{
716 struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);
717 unsigned int *new_delay = data;
718 int ret = 0;
719
720 /*
721 * Couple devfreq-device with the governor early because it is
722 * needed at the moment of governor's start (used by ISR).
723 */
724 tegra->devfreq = devfreq;
725
726 switch (event) {
727 case DEVFREQ_GOV_START:
728 devfreq_monitor_start(devfreq);
729 ret = tegra_actmon_start(tegra);
730 break;
731
732 case DEVFREQ_GOV_STOP:
733 tegra_actmon_stop(tegra);
734 devfreq_monitor_stop(devfreq);
735 break;
736
737 case DEVFREQ_GOV_UPDATE_INTERVAL:
738 /*
739 * ACTMON hardware supports up to 256 milliseconds for the
740 * sampling period.
741 */
742 if (*new_delay > 256) {
743 ret = -EINVAL;
744 break;
745 }
746
747 tegra_actmon_pause(tegra);
748 devfreq_update_interval(devfreq, new_delay);
749 ret = tegra_actmon_resume(tegra);
750 break;
751
752 case DEVFREQ_GOV_SUSPEND:
753 tegra_actmon_stop(tegra);
754 devfreq_monitor_suspend(devfreq);
755 break;
756
757 case DEVFREQ_GOV_RESUME:
758 devfreq_monitor_resume(devfreq);
759 ret = tegra_actmon_start(tegra);
760 break;
761 }
762
763 return ret;
764}
765
766static struct devfreq_governor tegra_devfreq_governor = {
767 .name = "tegra_actmon",
768 .get_target_freq = tegra_governor_get_target,
769 .event_handler = tegra_governor_event_handler,
770 .immutable = true,
771 .interrupt_driven = true,
772};
773
774static int tegra_devfreq_probe(struct platform_device *pdev)
775{
776 struct tegra_devfreq_device *dev;
777 struct tegra_devfreq *tegra;
778 struct devfreq *devfreq;
779 unsigned int i;
780 long rate;
781 int err;
782
783 tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
784 if (!tegra)
785 return -ENOMEM;
786
787 tegra->regs = devm_platform_ioremap_resource(pdev, 0);
788 if (IS_ERR(tegra->regs))
789 return PTR_ERR(tegra->regs);
790
791 tegra->reset = devm_reset_control_get(&pdev->dev, "actmon");
792 if (IS_ERR(tegra->reset)) {
793 dev_err(&pdev->dev, "Failed to get reset\n");
794 return PTR_ERR(tegra->reset);
795 }
796
797 tegra->clock = devm_clk_get(&pdev->dev, "actmon");
798 if (IS_ERR(tegra->clock)) {
799 dev_err(&pdev->dev, "Failed to get actmon clock\n");
800 return PTR_ERR(tegra->clock);
801 }
802
803 tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
804 if (IS_ERR(tegra->emc_clock)) {
805 dev_err(&pdev->dev, "Failed to get emc clock\n");
806 return PTR_ERR(tegra->emc_clock);
807 }
808
809 err = platform_get_irq(pdev, 0);
810 if (err < 0)
811 return err;
812
813 tegra->irq = err;
814
815 irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN);
816
817 err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
818 actmon_thread_isr, IRQF_ONESHOT,
819 "tegra-devfreq", tegra);
820 if (err) {
821 dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
822 return err;
823 }
824
825 reset_control_assert(tegra->reset);
826
827 err = clk_prepare_enable(tegra->clock);
828 if (err) {
829 dev_err(&pdev->dev,
830 "Failed to prepare and enable ACTMON clock\n");
831 return err;
832 }
833
834 reset_control_deassert(tegra->reset);
835
836 rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
837 if (rate < 0) {
838 dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
839 err = rate;
840 goto disable_clk;
841 }
842
843 tegra->max_freq = rate / KHZ;
844
845 for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
846 dev = tegra->devices + i;
847 dev->config = actmon_device_configs + i;
848 dev->regs = tegra->regs + dev->config->offset;
849 }
850
851 for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
852 rate = clk_round_rate(tegra->emc_clock, rate);
853
854 if (rate < 0) {
855 dev_err(&pdev->dev,
856 "Failed to round clock rate: %ld\n", rate);
857 err = rate;
858 goto remove_opps;
859 }
860
861 err = dev_pm_opp_add(&pdev->dev, rate / KHZ, 0);
862 if (err) {
863 dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
864 goto remove_opps;
865 }
866 }
867
868 platform_set_drvdata(pdev, tegra);
869
870 tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb;
871 tegra->cpu_rate_change_nb.notifier_call = tegra_actmon_cpu_notify_cb;
872
873 INIT_DELAYED_WORK(&tegra->cpufreq_update_work,
874 tegra_actmon_delayed_update);
875
876 err = devfreq_add_governor(&tegra_devfreq_governor);
877 if (err) {
878 dev_err(&pdev->dev, "Failed to add governor: %d\n", err);
879 goto remove_opps;
880 }
881
882 tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
883 tegra_devfreq_profile.initial_freq /= KHZ;
884
885 devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
886 "tegra_actmon", NULL);
887 if (IS_ERR(devfreq)) {
888 err = PTR_ERR(devfreq);
889 goto remove_governor;
890 }
891
892 return 0;
893
894remove_governor:
895 devfreq_remove_governor(&tegra_devfreq_governor);
896
897remove_opps:
898 dev_pm_opp_remove_all_dynamic(&pdev->dev);
899
900 reset_control_reset(tegra->reset);
901disable_clk:
902 clk_disable_unprepare(tegra->clock);
903
904 return err;
905}
906
907static int tegra_devfreq_remove(struct platform_device *pdev)
908{
909 struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
910
911 devfreq_remove_device(tegra->devfreq);
912 devfreq_remove_governor(&tegra_devfreq_governor);
913
914 dev_pm_opp_remove_all_dynamic(&pdev->dev);
915
916 reset_control_reset(tegra->reset);
917 clk_disable_unprepare(tegra->clock);
918
919 return 0;
920}
921
922static const struct of_device_id tegra_devfreq_of_match[] = {
923 { .compatible = "nvidia,tegra30-actmon" },
924 { .compatible = "nvidia,tegra124-actmon" },
925 { },
926};
927
928MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match);
929
930static struct platform_driver tegra_devfreq_driver = {
931 .probe = tegra_devfreq_probe,
932 .remove = tegra_devfreq_remove,
933 .driver = {
934 .name = "tegra-devfreq",
935 .of_match_table = tegra_devfreq_of_match,
936 },
937};
938module_platform_driver(tegra_devfreq_driver);
939
940MODULE_LICENSE("GPL v2");
941MODULE_DESCRIPTION("Tegra devfreq driver");
942MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>");