1// SPDX-License-Identifier: GPL-2.0
2/* Copyright 2019 Collabora ltd. */
3
4#include <linux/clk.h>
5#include <linux/devfreq.h>
6#include <linux/devfreq_cooling.h>
7#include <linux/platform_device.h>
8#include <linux/pm_opp.h>
9
10#include "panfrost_device.h"
11#include "panfrost_devfreq.h"
12
13static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfreq)
14{
15	ktime_t now, last;
16
17	now = ktime_get();
18	last = pfdevfreq->time_last_update;
19
20	if (pfdevfreq->busy_count > 0)
21		pfdevfreq->busy_time += ktime_sub(now, last);
22	else
23		pfdevfreq->idle_time += ktime_sub(now, last);
24
25	pfdevfreq->time_last_update = now;
26}
27
28static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
29				   u32 flags)
30{
31	struct dev_pm_opp *opp;
32	int err;
33
34	opp = devfreq_recommended_opp(dev, freq, flags);
35	if (IS_ERR(opp))
36		return PTR_ERR(opp);
37	dev_pm_opp_put(opp);
38
39	err = dev_pm_opp_set_rate(dev, *freq);
40	if (err)
41		return err;
42
43	return 0;
44}
45
46static void panfrost_devfreq_reset(struct panfrost_devfreq *pfdevfreq)
47{
48	pfdevfreq->busy_time = 0;
49	pfdevfreq->idle_time = 0;
50	pfdevfreq->time_last_update = ktime_get();
51}
52
53static int panfrost_devfreq_get_dev_status(struct device *dev,
54					   struct devfreq_dev_status *status)
55{
56	struct panfrost_device *pfdev = dev_get_drvdata(dev);
57	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
58	unsigned long irqflags;
59
60	status->current_frequency = clk_get_rate(pfdev->clock);
61
62	spin_lock_irqsave(&pfdevfreq->lock, irqflags);
63
64	panfrost_devfreq_update_utilization(pfdevfreq);
65
66	status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time,
67						   pfdevfreq->idle_time));
68
69	status->busy_time = ktime_to_ns(pfdevfreq->busy_time);
70
71	panfrost_devfreq_reset(pfdevfreq);
72
73	spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
74
75	dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n",
76		status->busy_time, status->total_time,
77		status->busy_time / (status->total_time / 100),
78		status->current_frequency / 1000 / 1000);
79
80	return 0;
81}
82
83static struct devfreq_dev_profile panfrost_devfreq_profile = {
84	.polling_ms = 50, /* ~3 frames */
85	.target = panfrost_devfreq_target,
86	.get_dev_status = panfrost_devfreq_get_dev_status,
87};
88
89int panfrost_devfreq_init(struct panfrost_device *pfdev)
90{
91	int ret;
92	struct dev_pm_opp *opp;
93	unsigned long cur_freq;
94	struct device *dev = &pfdev->pdev->dev;
95	struct devfreq *devfreq;
96	struct opp_table *opp_table;
97	struct thermal_cooling_device *cooling;
98	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
99
100	opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
101					      pfdev->comp->num_supplies);
102	if (IS_ERR(opp_table)) {
103		ret = PTR_ERR(opp_table);
104		/* Continue if the optional regulator is missing */
105		if (ret != -ENODEV) {
106			DRM_DEV_ERROR(dev, "Couldn't set OPP regulators\n");
107			goto err_fini;
108		}
109	} else {
110		pfdevfreq->regulators_opp_table = opp_table;
111	}
112
113	ret = dev_pm_opp_of_add_table(dev);
114	if (ret) {
115		/* Optional, continue without devfreq */
116		if (ret == -ENODEV)
117			ret = 0;
118		goto err_fini;
119	}
120	pfdevfreq->opp_of_table_added = true;
121
122	spin_lock_init(&pfdevfreq->lock);
123
124	panfrost_devfreq_reset(pfdevfreq);
125
126	cur_freq = clk_get_rate(pfdev->clock);
127
128	opp = devfreq_recommended_opp(dev, &cur_freq, 0);
129	if (IS_ERR(opp)) {
130		ret = PTR_ERR(opp);
131		goto err_fini;
132	}
133
134	panfrost_devfreq_profile.initial_freq = cur_freq;
135	dev_pm_opp_put(opp);
136
137	devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile,
138					  DEVFREQ_GOV_SIMPLE_ONDEMAND, NULL);
139	if (IS_ERR(devfreq)) {
140		DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n");
141		ret = PTR_ERR(devfreq);
142		goto err_fini;
143	}
144	pfdevfreq->devfreq = devfreq;
145
146	cooling = of_devfreq_cooling_register(dev->of_node, devfreq);
147	if (IS_ERR(cooling))
148		DRM_DEV_INFO(dev, "Failed to register cooling device\n");
149	else
150		pfdevfreq->cooling = cooling;
151
152	return 0;
153
154err_fini:
155	panfrost_devfreq_fini(pfdev);
156	return ret;
157}
158
159void panfrost_devfreq_fini(struct panfrost_device *pfdev)
160{
161	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
162
163	if (pfdevfreq->cooling) {
164		devfreq_cooling_unregister(pfdevfreq->cooling);
165		pfdevfreq->cooling = NULL;
166	}
167
168	if (pfdevfreq->opp_of_table_added) {
169		dev_pm_opp_of_remove_table(&pfdev->pdev->dev);
170		pfdevfreq->opp_of_table_added = false;
171	}
172
173	if (pfdevfreq->regulators_opp_table) {
174		dev_pm_opp_put_regulators(pfdevfreq->regulators_opp_table);
175		pfdevfreq->regulators_opp_table = NULL;
176	}
177}
178
179void panfrost_devfreq_resume(struct panfrost_device *pfdev)
180{
181	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
182
183	if (!pfdevfreq->devfreq)
184		return;
185
186	panfrost_devfreq_reset(pfdevfreq);
187
188	devfreq_resume_device(pfdevfreq->devfreq);
189}
190
191void panfrost_devfreq_suspend(struct panfrost_device *pfdev)
192{
193	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
194
195	if (!pfdevfreq->devfreq)
196		return;
197
198	devfreq_suspend_device(pfdevfreq->devfreq);
199}
200
201void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq)
202{
203	unsigned long irqflags;
204
205	if (!pfdevfreq->devfreq)
206		return;
207
208	spin_lock_irqsave(&pfdevfreq->lock, irqflags);
209
210	panfrost_devfreq_update_utilization(pfdevfreq);
211
212	pfdevfreq->busy_count++;
213
214	spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
215}
216
217void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq)
218{
219	unsigned long irqflags;
220
221	if (!pfdevfreq->devfreq)
222		return;
223
224	spin_lock_irqsave(&pfdevfreq->lock, irqflags);
225
226	panfrost_devfreq_update_utilization(pfdevfreq);
227
228	WARN_ON(--pfdevfreq->busy_count < 0);
229
230	spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
231}
232