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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/module.h>
15#include <linux/mod_devicetable.h>
16#include <linux/platform_device.h>
17#include <linux/pm_opp.h>
18#include <linux/reset.h>
19
20#include "governor.h"
21
22#define ACTMON_GLB_STATUS 0x0
23#define ACTMON_GLB_PERIOD_CTRL 0x4
24
25#define ACTMON_DEV_CTRL 0x0
26#define ACTMON_DEV_CTRL_K_VAL_SHIFT 10
27#define ACTMON_DEV_CTRL_ENB_PERIODIC BIT(18)
28#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN BIT(20)
29#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN BIT(21)
30#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT 23
31#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT 26
32#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN BIT(29)
33#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN BIT(30)
34#define ACTMON_DEV_CTRL_ENB BIT(31)
35
36#define ACTMON_DEV_UPPER_WMARK 0x4
37#define ACTMON_DEV_LOWER_WMARK 0x8
38#define ACTMON_DEV_INIT_AVG 0xc
39#define ACTMON_DEV_AVG_UPPER_WMARK 0x10
40#define ACTMON_DEV_AVG_LOWER_WMARK 0x14
41#define ACTMON_DEV_COUNT_WEIGHT 0x18
42#define ACTMON_DEV_AVG_COUNT 0x20
43#define ACTMON_DEV_INTR_STATUS 0x24
44
45#define ACTMON_INTR_STATUS_CLEAR 0xffffffff
46
47#define ACTMON_DEV_INTR_CONSECUTIVE_UPPER BIT(31)
48#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER BIT(30)
49
50#define ACTMON_ABOVE_WMARK_WINDOW 1
51#define ACTMON_BELOW_WMARK_WINDOW 3
52#define ACTMON_BOOST_FREQ_STEP 16000
53
54/*
55 * Activity counter is incremented every 256 memory transactions, and each
56 * transaction takes 4 EMC clocks for Tegra124; So the COUNT_WEIGHT is
57 * 4 * 256 = 1024.
58 */
59#define ACTMON_COUNT_WEIGHT 0x400
60
61/*
62 * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which
63 * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128
64 */
65#define ACTMON_AVERAGE_WINDOW_LOG2 6
66#define ACTMON_SAMPLING_PERIOD 12 /* ms */
67#define ACTMON_DEFAULT_AVG_BAND 6 /* 1/10 of % */
68
69#define KHZ 1000
70
71/* Assume that the bus is saturated if the utilization is 25% */
72#define BUS_SATURATION_RATIO 25
73
74/**
75 * struct tegra_devfreq_device_config - configuration specific to an ACTMON
76 * device
77 *
78 * Coefficients and thresholds are percentages unless otherwise noted
79 */
80struct tegra_devfreq_device_config {
81 u32 offset;
82 u32 irq_mask;
83
84 /* Factors applied to boost_freq every consecutive watermark breach */
85 unsigned int boost_up_coeff;
86 unsigned int boost_down_coeff;
87
88 /* Define the watermark bounds when applied to the current avg */
89 unsigned int boost_up_threshold;
90 unsigned int boost_down_threshold;
91
92 /*
93 * Threshold of activity (cycles) below which the CPU frequency isn't
94 * to be taken into account. This is to avoid increasing the EMC
95 * frequency when the CPU is very busy but not accessing the bus often.
96 */
97 u32 avg_dependency_threshold;
98};
99
100enum tegra_actmon_device {
101 MCALL = 0,
102 MCCPU,
103};
104
105static struct tegra_devfreq_device_config actmon_device_configs[] = {
106 {
107 /* MCALL: All memory accesses (including from the CPUs) */
108 .offset = 0x1c0,
109 .irq_mask = 1 << 26,
110 .boost_up_coeff = 200,
111 .boost_down_coeff = 50,
112 .boost_up_threshold = 60,
113 .boost_down_threshold = 40,
114 },
115 {
116 /* MCCPU: memory accesses from the CPUs */
117 .offset = 0x200,
118 .irq_mask = 1 << 25,
119 .boost_up_coeff = 800,
120 .boost_down_coeff = 90,
121 .boost_up_threshold = 27,
122 .boost_down_threshold = 10,
123 .avg_dependency_threshold = 50000,
124 },
125};
126
127/**
128 * struct tegra_devfreq_device - state specific to an ACTMON device
129 *
130 * Frequencies are in kHz.
131 */
132struct tegra_devfreq_device {
133 const struct tegra_devfreq_device_config *config;
134 void __iomem *regs;
135
136 /* Average event count sampled in the last interrupt */
137 u32 avg_count;
138
139 /*
140 * Extra frequency to increase the target by due to consecutive
141 * watermark breaches.
142 */
143 unsigned long boost_freq;
144
145 /* Optimal frequency calculated from the stats for this device */
146 unsigned long target_freq;
147};
148
149struct tegra_devfreq {
150 struct devfreq *devfreq;
151
152 struct reset_control *reset;
153 struct clk *clock;
154 void __iomem *regs;
155
156 struct clk *emc_clock;
157 unsigned long max_freq;
158 unsigned long cur_freq;
159 struct notifier_block rate_change_nb;
160
161 struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];
162
163 int irq;
164};
165
166struct tegra_actmon_emc_ratio {
167 unsigned long cpu_freq;
168 unsigned long emc_freq;
169};
170
171static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
172 { 1400000, ULONG_MAX },
173 { 1200000, 750000 },
174 { 1100000, 600000 },
175 { 1000000, 500000 },
176 { 800000, 375000 },
177 { 500000, 200000 },
178 { 250000, 100000 },
179};
180
181static u32 actmon_readl(struct tegra_devfreq *tegra, u32 offset)
182{
183 return readl_relaxed(tegra->regs + offset);
184}
185
186static void actmon_writel(struct tegra_devfreq *tegra, u32 val, u32 offset)
187{
188 writel_relaxed(val, tegra->regs + offset);
189}
190
191static u32 device_readl(struct tegra_devfreq_device *dev, u32 offset)
192{
193 return readl_relaxed(dev->regs + offset);
194}
195
196static void device_writel(struct tegra_devfreq_device *dev, u32 val,
197 u32 offset)
198{
199 writel_relaxed(val, dev->regs + offset);
200}
201
202static unsigned long do_percent(unsigned long val, unsigned int pct)
203{
204 return val * pct / 100;
205}
206
207static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra,
208 struct tegra_devfreq_device *dev)
209{
210 u32 avg = dev->avg_count;
211 u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;
212 u32 band = avg_band_freq * ACTMON_SAMPLING_PERIOD;
213
214 device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK);
215
216 avg = max(dev->avg_count, band);
217 device_writel(dev, avg - band, ACTMON_DEV_AVG_LOWER_WMARK);
218}
219
220static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,
221 struct tegra_devfreq_device *dev)
222{
223 u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
224
225 device_writel(dev, do_percent(val, dev->config->boost_up_threshold),
226 ACTMON_DEV_UPPER_WMARK);
227
228 device_writel(dev, do_percent(val, dev->config->boost_down_threshold),
229 ACTMON_DEV_LOWER_WMARK);
230}
231
232static void actmon_write_barrier(struct tegra_devfreq *tegra)
233{
234 /* ensure the update has reached the ACTMON */
235 readl(tegra->regs + ACTMON_GLB_STATUS);
236}
237
238static void actmon_isr_device(struct tegra_devfreq *tegra,
239 struct tegra_devfreq_device *dev)
240{
241 u32 intr_status, dev_ctrl;
242
243 dev->avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT);
244 tegra_devfreq_update_avg_wmark(tegra, dev);
245
246 intr_status = device_readl(dev, ACTMON_DEV_INTR_STATUS);
247 dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL);
248
249 if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) {
250 /*
251 * new_boost = min(old_boost * up_coef + step, max_freq)
252 */
253 dev->boost_freq = do_percent(dev->boost_freq,
254 dev->config->boost_up_coeff);
255 dev->boost_freq += ACTMON_BOOST_FREQ_STEP;
256
257 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
258
259 if (dev->boost_freq >= tegra->max_freq)
260 dev->boost_freq = tegra->max_freq;
261 else
262 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
263 } else if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) {
264 /*
265 * new_boost = old_boost * down_coef
266 * or 0 if (old_boost * down_coef < step / 2)
267 */
268 dev->boost_freq = do_percent(dev->boost_freq,
269 dev->config->boost_down_coeff);
270
271 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
272
273 if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1))
274 dev->boost_freq = 0;
275 else
276 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
277 }
278
279 if (dev->config->avg_dependency_threshold) {
280 if (dev->avg_count >= dev->config->avg_dependency_threshold)
281 dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
282 else if (dev->boost_freq == 0)
283 dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
284 }
285
286 device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL);
287
288 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
289
290 actmon_write_barrier(tegra);
291}
292
293static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
294 unsigned long cpu_freq)
295{
296 unsigned int i;
297 struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
298
299 for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {
300 if (cpu_freq >= ratio->cpu_freq) {
301 if (ratio->emc_freq >= tegra->max_freq)
302 return tegra->max_freq;
303 else
304 return ratio->emc_freq;
305 }
306 }
307
308 return 0;
309}
310
311static void actmon_update_target(struct tegra_devfreq *tegra,
312 struct tegra_devfreq_device *dev)
313{
314 unsigned long cpu_freq = 0;
315 unsigned long static_cpu_emc_freq = 0;
316 unsigned int avg_sustain_coef;
317
318 if (dev->config->avg_dependency_threshold) {
319 cpu_freq = cpufreq_get(0);
320 static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
321 }
322
323 dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
324 avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
325 dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef);
326 dev->target_freq += dev->boost_freq;
327
328 if (dev->avg_count >= dev->config->avg_dependency_threshold)
329 dev->target_freq = max(dev->target_freq, static_cpu_emc_freq);
330}
331
332static irqreturn_t actmon_thread_isr(int irq, void *data)
333{
334 struct tegra_devfreq *tegra = data;
335 bool handled = false;
336 unsigned int i;
337 u32 val;
338
339 mutex_lock(&tegra->devfreq->lock);
340
341 val = actmon_readl(tegra, ACTMON_GLB_STATUS);
342 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
343 if (val & tegra->devices[i].config->irq_mask) {
344 actmon_isr_device(tegra, tegra->devices + i);
345 handled = true;
346 }
347 }
348
349 if (handled)
350 update_devfreq(tegra->devfreq);
351
352 mutex_unlock(&tegra->devfreq->lock);
353
354 return handled ? IRQ_HANDLED : IRQ_NONE;
355}
356
357static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,
358 unsigned long action, void *ptr)
359{
360 struct clk_notifier_data *data = ptr;
361 struct tegra_devfreq *tegra;
362 struct tegra_devfreq_device *dev;
363 unsigned int i;
364
365 if (action != POST_RATE_CHANGE)
366 return NOTIFY_OK;
367
368 tegra = container_of(nb, struct tegra_devfreq, rate_change_nb);
369
370 tegra->cur_freq = data->new_rate / KHZ;
371
372 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
373 dev = &tegra->devices[i];
374
375 tegra_devfreq_update_wmark(tegra, dev);
376 }
377
378 actmon_write_barrier(tegra);
379
380 return NOTIFY_OK;
381}
382
383static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
384 struct tegra_devfreq_device *dev)
385{
386 u32 val = 0;
387
388 dev->target_freq = tegra->cur_freq;
389
390 dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
391 device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG);
392
393 tegra_devfreq_update_avg_wmark(tegra, dev);
394 tegra_devfreq_update_wmark(tegra, dev);
395
396 device_writel(dev, ACTMON_COUNT_WEIGHT, ACTMON_DEV_COUNT_WEIGHT);
397 device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
398
399 val |= ACTMON_DEV_CTRL_ENB_PERIODIC;
400 val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1)
401 << ACTMON_DEV_CTRL_K_VAL_SHIFT;
402 val |= (ACTMON_BELOW_WMARK_WINDOW - 1)
403 << ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT;
404 val |= (ACTMON_ABOVE_WMARK_WINDOW - 1)
405 << ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT;
406 val |= ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN;
407 val |= ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;
408 val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
409 val |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
410 val |= ACTMON_DEV_CTRL_ENB;
411
412 device_writel(dev, val, ACTMON_DEV_CTRL);
413}
414
415static void tegra_actmon_start(struct tegra_devfreq *tegra)
416{
417 unsigned int i;
418
419 disable_irq(tegra->irq);
420
421 actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
422 ACTMON_GLB_PERIOD_CTRL);
423
424 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++)
425 tegra_actmon_configure_device(tegra, &tegra->devices[i]);
426
427 actmon_write_barrier(tegra);
428
429 enable_irq(tegra->irq);
430}
431
432static void tegra_actmon_stop(struct tegra_devfreq *tegra)
433{
434 unsigned int i;
435
436 disable_irq(tegra->irq);
437
438 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
439 device_writel(&tegra->devices[i], 0x00000000, ACTMON_DEV_CTRL);
440 device_writel(&tegra->devices[i], ACTMON_INTR_STATUS_CLEAR,
441 ACTMON_DEV_INTR_STATUS);
442 }
443
444 actmon_write_barrier(tegra);
445
446 enable_irq(tegra->irq);
447}
448
449static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
450 u32 flags)
451{
452 struct tegra_devfreq *tegra = dev_get_drvdata(dev);
453 struct devfreq *devfreq = tegra->devfreq;
454 struct dev_pm_opp *opp;
455 unsigned long rate;
456 int err;
457
458 opp = devfreq_recommended_opp(dev, freq, flags);
459 if (IS_ERR(opp)) {
460 dev_err(dev, "Failed to find opp for %lu Hz\n", *freq);
461 return PTR_ERR(opp);
462 }
463 rate = dev_pm_opp_get_freq(opp);
464 dev_pm_opp_put(opp);
465
466 err = clk_set_min_rate(tegra->emc_clock, rate);
467 if (err)
468 return err;
469
470 err = clk_set_rate(tegra->emc_clock, 0);
471 if (err)
472 goto restore_min_rate;
473
474 return 0;
475
476restore_min_rate:
477 clk_set_min_rate(tegra->emc_clock, devfreq->previous_freq);
478
479 return err;
480}
481
482static int tegra_devfreq_get_dev_status(struct device *dev,
483 struct devfreq_dev_status *stat)
484{
485 struct tegra_devfreq *tegra = dev_get_drvdata(dev);
486 struct tegra_devfreq_device *actmon_dev;
487 unsigned long cur_freq;
488
489 cur_freq = READ_ONCE(tegra->cur_freq);
490
491 /* To be used by the tegra governor */
492 stat->private_data = tegra;
493
494 /* The below are to be used by the other governors */
495 stat->current_frequency = cur_freq * KHZ;
496
497 actmon_dev = &tegra->devices[MCALL];
498
499 /* Number of cycles spent on memory access */
500 stat->busy_time = device_readl(actmon_dev, ACTMON_DEV_AVG_COUNT);
501
502 /* The bus can be considered to be saturated way before 100% */
503 stat->busy_time *= 100 / BUS_SATURATION_RATIO;
504
505 /* Number of cycles in a sampling period */
506 stat->total_time = ACTMON_SAMPLING_PERIOD * cur_freq;
507
508 stat->busy_time = min(stat->busy_time, stat->total_time);
509
510 return 0;
511}
512
513static struct devfreq_dev_profile tegra_devfreq_profile = {
514 .polling_ms = 0,
515 .target = tegra_devfreq_target,
516 .get_dev_status = tegra_devfreq_get_dev_status,
517};
518
519static int tegra_governor_get_target(struct devfreq *devfreq,
520 unsigned long *freq)
521{
522 struct devfreq_dev_status *stat;
523 struct tegra_devfreq *tegra;
524 struct tegra_devfreq_device *dev;
525 unsigned long target_freq = 0;
526 unsigned int i;
527 int err;
528
529 err = devfreq_update_stats(devfreq);
530 if (err)
531 return err;
532
533 stat = &devfreq->last_status;
534
535 tegra = stat->private_data;
536
537 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
538 dev = &tegra->devices[i];
539
540 actmon_update_target(tegra, dev);
541
542 target_freq = max(target_freq, dev->target_freq);
543 }
544
545 *freq = target_freq * KHZ;
546
547 return 0;
548}
549
550static int tegra_governor_event_handler(struct devfreq *devfreq,
551 unsigned int event, void *data)
552{
553 struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);
554
555 switch (event) {
556 case DEVFREQ_GOV_START:
557 devfreq_monitor_start(devfreq);
558 tegra_actmon_start(tegra);
559 break;
560
561 case DEVFREQ_GOV_STOP:
562 tegra_actmon_stop(tegra);
563 devfreq_monitor_stop(devfreq);
564 break;
565
566 case DEVFREQ_GOV_SUSPEND:
567 tegra_actmon_stop(tegra);
568 devfreq_monitor_suspend(devfreq);
569 break;
570
571 case DEVFREQ_GOV_RESUME:
572 devfreq_monitor_resume(devfreq);
573 tegra_actmon_start(tegra);
574 break;
575 }
576
577 return 0;
578}
579
580static struct devfreq_governor tegra_devfreq_governor = {
581 .name = "tegra_actmon",
582 .get_target_freq = tegra_governor_get_target,
583 .event_handler = tegra_governor_event_handler,
584 .immutable = true,
585};
586
587static int tegra_devfreq_probe(struct platform_device *pdev)
588{
589 struct tegra_devfreq *tegra;
590 struct tegra_devfreq_device *dev;
591 unsigned int i;
592 unsigned long rate;
593 int err;
594
595 tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
596 if (!tegra)
597 return -ENOMEM;
598
599 tegra->regs = devm_platform_ioremap_resource(pdev, 0);
600 if (IS_ERR(tegra->regs))
601 return PTR_ERR(tegra->regs);
602
603 tegra->reset = devm_reset_control_get(&pdev->dev, "actmon");
604 if (IS_ERR(tegra->reset)) {
605 dev_err(&pdev->dev, "Failed to get reset\n");
606 return PTR_ERR(tegra->reset);
607 }
608
609 tegra->clock = devm_clk_get(&pdev->dev, "actmon");
610 if (IS_ERR(tegra->clock)) {
611 dev_err(&pdev->dev, "Failed to get actmon clock\n");
612 return PTR_ERR(tegra->clock);
613 }
614
615 tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
616 if (IS_ERR(tegra->emc_clock)) {
617 dev_err(&pdev->dev, "Failed to get emc clock\n");
618 return PTR_ERR(tegra->emc_clock);
619 }
620
621 tegra->irq = platform_get_irq(pdev, 0);
622 if (tegra->irq < 0) {
623 err = tegra->irq;
624 dev_err(&pdev->dev, "Failed to get IRQ: %d\n", err);
625 return err;
626 }
627
628 reset_control_assert(tegra->reset);
629
630 err = clk_prepare_enable(tegra->clock);
631 if (err) {
632 dev_err(&pdev->dev,
633 "Failed to prepare and enable ACTMON clock\n");
634 return err;
635 }
636
637 reset_control_deassert(tegra->reset);
638
639 tegra->max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX) / KHZ;
640 tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
641
642 for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
643 dev = tegra->devices + i;
644 dev->config = actmon_device_configs + i;
645 dev->regs = tegra->regs + dev->config->offset;
646 }
647
648 for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
649 rate = clk_round_rate(tegra->emc_clock, rate);
650
651 err = dev_pm_opp_add(&pdev->dev, rate, 0);
652 if (err) {
653 dev_err(&pdev->dev, "Failed to add OPP: %d\n", err);
654 goto remove_opps;
655 }
656 }
657
658 platform_set_drvdata(pdev, tegra);
659
660 tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb;
661 err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb);
662 if (err) {
663 dev_err(&pdev->dev,
664 "Failed to register rate change notifier\n");
665 goto remove_opps;
666 }
667
668 err = devfreq_add_governor(&tegra_devfreq_governor);
669 if (err) {
670 dev_err(&pdev->dev, "Failed to add governor: %d\n", err);
671 goto unreg_notifier;
672 }
673
674 tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
675 tegra->devfreq = devfreq_add_device(&pdev->dev,
676 &tegra_devfreq_profile,
677 "tegra_actmon",
678 NULL);
679 if (IS_ERR(tegra->devfreq)) {
680 err = PTR_ERR(tegra->devfreq);
681 goto remove_governor;
682 }
683
684 err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
685 actmon_thread_isr, IRQF_ONESHOT,
686 "tegra-devfreq", tegra);
687 if (err) {
688 dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
689 goto remove_devfreq;
690 }
691
692 return 0;
693
694remove_devfreq:
695 devfreq_remove_device(tegra->devfreq);
696
697remove_governor:
698 devfreq_remove_governor(&tegra_devfreq_governor);
699
700unreg_notifier:
701 clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb);
702
703remove_opps:
704 dev_pm_opp_remove_all_dynamic(&pdev->dev);
705
706 reset_control_reset(tegra->reset);
707 clk_disable_unprepare(tegra->clock);
708
709 return err;
710}
711
712static int tegra_devfreq_remove(struct platform_device *pdev)
713{
714 struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
715
716 devfreq_remove_device(tegra->devfreq);
717 devfreq_remove_governor(&tegra_devfreq_governor);
718
719 clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb);
720 dev_pm_opp_remove_all_dynamic(&pdev->dev);
721
722 reset_control_reset(tegra->reset);
723 clk_disable_unprepare(tegra->clock);
724
725 return 0;
726}
727
728static const struct of_device_id tegra_devfreq_of_match[] = {
729 { .compatible = "nvidia,tegra30-actmon" },
730 { .compatible = "nvidia,tegra124-actmon" },
731 { },
732};
733
734MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match);
735
736static struct platform_driver tegra_devfreq_driver = {
737 .probe = tegra_devfreq_probe,
738 .remove = tegra_devfreq_remove,
739 .driver = {
740 .name = "tegra-devfreq",
741 .of_match_table = tegra_devfreq_of_match,
742 },
743};
744module_platform_driver(tegra_devfreq_driver);
745
746MODULE_LICENSE("GPL v2");
747MODULE_DESCRIPTION("Tegra devfreq driver");
748MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>");