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
panfrost_devfreq_update_utilization(struct panfrost_devfreq * pfdevfreq)13 static 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
panfrost_devfreq_target(struct device * dev,unsigned long * freq,u32 flags)28 static 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
panfrost_devfreq_reset(struct panfrost_devfreq * pfdevfreq)46 static 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
panfrost_devfreq_get_dev_status(struct device * dev,struct devfreq_dev_status * status)53 static 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
83 static 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
panfrost_devfreq_init(struct panfrost_device * pfdev)89 int 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
154 err_fini:
155 panfrost_devfreq_fini(pfdev);
156 return ret;
157 }
158
panfrost_devfreq_fini(struct panfrost_device * pfdev)159 void 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
panfrost_devfreq_resume(struct panfrost_device * pfdev)179 void 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
panfrost_devfreq_suspend(struct panfrost_device * pfdev)191 void 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
panfrost_devfreq_record_busy(struct panfrost_devfreq * pfdevfreq)201 void 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
panfrost_devfreq_record_idle(struct panfrost_devfreq * pfdevfreq)217 void 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