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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 opp = devfreq_recommended_opp(dev, &rate, flags);
491 if (IS_ERR(opp)) {
492 dev_err(dev, "Failed to find opp for %lu KHz\n", *freq);
493 return PTR_ERR(opp);
494 }
495 rate = dev_pm_opp_get_freq(opp);
496 dev_pm_opp_put(opp);
497
498 clk_set_min_rate(tegra->emc_clock, rate);
499 clk_set_rate(tegra->emc_clock, 0);
500
501 *freq = rate;
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_update_stats(devfreq);
552 if (err)
553 return err;
554
555 stat = &devfreq->last_status;
556
557 tegra = stat->private_data;
558
559 for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
560 dev = &tegra->devices[i];
561
562 actmon_update_target(tegra, dev);
563
564 target_freq = max(target_freq, dev->target_freq);
565 }
566
567 *freq = target_freq;
568
569 return 0;
570}
571
572static int tegra_governor_event_handler(struct devfreq *devfreq,
573 unsigned int event, void *data)
574{
575 struct tegra_devfreq *tegra;
576 int ret = 0;
577
578 tegra = dev_get_drvdata(devfreq->dev.parent);
579
580 switch (event) {
581 case DEVFREQ_GOV_START:
582 devfreq_monitor_start(devfreq);
583 tegra_actmon_enable_interrupts(tegra);
584 break;
585
586 case DEVFREQ_GOV_STOP:
587 tegra_actmon_disable_interrupts(tegra);
588 devfreq_monitor_stop(devfreq);
589 break;
590
591 case DEVFREQ_GOV_SUSPEND:
592 tegra_actmon_disable_interrupts(tegra);
593 devfreq_monitor_suspend(devfreq);
594 break;
595
596 case DEVFREQ_GOV_RESUME:
597 devfreq_monitor_resume(devfreq);
598 tegra_actmon_enable_interrupts(tegra);
599 break;
600 }
601
602 return ret;
603}
604
605static struct devfreq_governor tegra_devfreq_governor = {
606 .name = "tegra_actmon",
607 .get_target_freq = tegra_governor_get_target,
608 .event_handler = tegra_governor_event_handler,
609};
610
611static int tegra_devfreq_probe(struct platform_device *pdev)
612{
613 struct tegra_devfreq *tegra;
614 struct tegra_devfreq_device *dev;
615 struct resource *res;
616 unsigned int i;
617 unsigned long rate;
618 int irq;
619 int err;
620
621 tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
622 if (!tegra)
623 return -ENOMEM;
624
625 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
626
627 tegra->regs = devm_ioremap_resource(&pdev->dev, res);
628 if (IS_ERR(tegra->regs))
629 return PTR_ERR(tegra->regs);
630
631 tegra->reset = devm_reset_control_get(&pdev->dev, "actmon");
632 if (IS_ERR(tegra->reset)) {
633 dev_err(&pdev->dev, "Failed to get reset\n");
634 return PTR_ERR(tegra->reset);
635 }
636
637 tegra->clock = devm_clk_get(&pdev->dev, "actmon");
638 if (IS_ERR(tegra->clock)) {
639 dev_err(&pdev->dev, "Failed to get actmon clock\n");
640 return PTR_ERR(tegra->clock);
641 }
642
643 tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
644 if (IS_ERR(tegra->emc_clock)) {
645 dev_err(&pdev->dev, "Failed to get emc clock\n");
646 return PTR_ERR(tegra->emc_clock);
647 }
648
649 clk_set_rate(tegra->emc_clock, ULONG_MAX);
650
651 tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb;
652 err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb);
653 if (err) {
654 dev_err(&pdev->dev,
655 "Failed to register rate change notifier\n");
656 return err;
657 }
658
659 reset_control_assert(tegra->reset);
660
661 err = clk_prepare_enable(tegra->clock);
662 if (err) {
663 dev_err(&pdev->dev,
664 "Failed to prepare and enable ACTMON clock\n");
665 return err;
666 }
667
668 reset_control_deassert(tegra->reset);
669
670 tegra->max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX) / KHZ;
671 tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
672
673 actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
674 ACTMON_GLB_PERIOD_CTRL);
675
676 for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
677 dev = tegra->devices + i;
678 dev->config = actmon_device_configs + i;
679 dev->regs = tegra->regs + dev->config->offset;
680 spin_lock_init(&dev->lock);
681
682 tegra_actmon_configure_device(tegra, dev);
683 }
684
685 for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
686 rate = clk_round_rate(tegra->emc_clock, rate);
687 dev_pm_opp_add(&pdev->dev, rate, 0);
688 }
689
690 irq = platform_get_irq(pdev, 0);
691 if (irq < 0) {
692 dev_err(&pdev->dev, "Failed to get IRQ: %d\n", irq);
693 return irq;
694 }
695
696 platform_set_drvdata(pdev, tegra);
697
698 err = devm_request_threaded_irq(&pdev->dev, irq, actmon_isr,
699 actmon_thread_isr, IRQF_SHARED,
700 "tegra-devfreq", tegra);
701 if (err) {
702 dev_err(&pdev->dev, "Interrupt request failed\n");
703 return err;
704 }
705
706 tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
707 tegra->devfreq = devm_devfreq_add_device(&pdev->dev,
708 &tegra_devfreq_profile,
709 "tegra_actmon",
710 NULL);
711
712 return 0;
713}
714
715static int tegra_devfreq_remove(struct platform_device *pdev)
716{
717 struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
718 int irq = platform_get_irq(pdev, 0);
719 u32 val;
720 unsigned int i;
721
722 for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
723 val = device_readl(&tegra->devices[i], ACTMON_DEV_CTRL);
724 val &= ~ACTMON_DEV_CTRL_ENB;
725 device_writel(&tegra->devices[i], val, ACTMON_DEV_CTRL);
726 }
727
728 actmon_write_barrier(tegra);
729
730 devm_free_irq(&pdev->dev, irq, tegra);
731
732 clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb);
733
734 clk_disable_unprepare(tegra->clock);
735
736 return 0;
737}
738
739static const struct of_device_id tegra_devfreq_of_match[] = {
740 { .compatible = "nvidia,tegra124-actmon" },
741 { },
742};
743
744MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match);
745
746static struct platform_driver tegra_devfreq_driver = {
747 .probe = tegra_devfreq_probe,
748 .remove = tegra_devfreq_remove,
749 .driver = {
750 .name = "tegra-devfreq",
751 .of_match_table = tegra_devfreq_of_match,
752 },
753};
754
755static int __init tegra_devfreq_init(void)
756{
757 int ret = 0;
758
759 ret = devfreq_add_governor(&tegra_devfreq_governor);
760 if (ret) {
761 pr_err("%s: failed to add governor: %d\n", __func__, ret);
762 return ret;
763 }
764
765 ret = platform_driver_register(&tegra_devfreq_driver);
766 if (ret)
767 devfreq_remove_governor(&tegra_devfreq_governor);
768
769 return ret;
770}
771module_init(tegra_devfreq_init)
772
773static void __exit tegra_devfreq_exit(void)
774{
775 int ret = 0;
776
777 platform_driver_unregister(&tegra_devfreq_driver);
778
779 ret = devfreq_remove_governor(&tegra_devfreq_governor);
780 if (ret)
781 pr_err("%s: failed to remove governor: %d\n", __func__, ret);
782}
783module_exit(tegra_devfreq_exit)
784
785MODULE_LICENSE("GPL v2");
786MODULE_DESCRIPTION("Tegra devfreq driver");
787MODULE_AUTHOR("Tomeu Vizoso <[email protected]>");