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