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
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
panfrost_devfreq_reset(struct panfrost_devfreq * pfdevfreq)41 static 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
panfrost_devfreq_get_dev_status(struct device * dev,struct devfreq_dev_status * status)48 static 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
78 static 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
panfrost_devfreq_init(struct panfrost_device * pfdev)85 int 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 thermal_cooling_device *cooling;
93 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
94
95 if (pfdev->comp->num_supplies > 1) {
96 /*
97 * GPUs with more than 1 supply require platform-specific handling:
98 * continue without devfreq
99 */
100 DRM_DEV_INFO(dev, "More than 1 supply is not supported yet\n");
101 return 0;
102 }
103
104 ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
105 pfdev->comp->num_supplies);
106 if (ret) {
107 /* Continue if the optional regulator is missing */
108 if (ret != -ENODEV) {
109 if (ret != -EPROBE_DEFER)
110 DRM_DEV_ERROR(dev, "Couldn't set OPP regulators\n");
111 return ret;
112 }
113 }
114
115 ret = devm_pm_opp_of_add_table(dev);
116 if (ret) {
117 /* Optional, continue without devfreq */
118 if (ret == -ENODEV)
119 ret = 0;
120 return ret;
121 }
122 pfdevfreq->opp_of_table_added = true;
123
124 spin_lock_init(&pfdevfreq->lock);
125
126 panfrost_devfreq_reset(pfdevfreq);
127
128 cur_freq = clk_get_rate(pfdev->clock);
129
130 opp = devfreq_recommended_opp(dev, &cur_freq, 0);
131 if (IS_ERR(opp))
132 return PTR_ERR(opp);
133
134 panfrost_devfreq_profile.initial_freq = cur_freq;
135
136 /*
137 * Set the recommend OPP this will enable and configure the regulator
138 * if any and will avoid a switch off by regulator_late_cleanup()
139 */
140 ret = dev_pm_opp_set_opp(dev, opp);
141 if (ret) {
142 DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
143 return ret;
144 }
145
146 dev_pm_opp_put(opp);
147
148 /*
149 * Setup default thresholds for the simple_ondemand governor.
150 * The values are chosen based on experiments.
151 */
152 pfdevfreq->gov_data.upthreshold = 45;
153 pfdevfreq->gov_data.downdifferential = 5;
154
155 devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile,
156 DEVFREQ_GOV_SIMPLE_ONDEMAND,
157 &pfdevfreq->gov_data);
158 if (IS_ERR(devfreq)) {
159 DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n");
160 return PTR_ERR(devfreq);
161 }
162 pfdevfreq->devfreq = devfreq;
163
164 cooling = devfreq_cooling_em_register(devfreq, NULL);
165 if (IS_ERR(cooling))
166 DRM_DEV_INFO(dev, "Failed to register cooling device\n");
167 else
168 pfdevfreq->cooling = cooling;
169
170 return 0;
171 }
172
panfrost_devfreq_fini(struct panfrost_device * pfdev)173 void panfrost_devfreq_fini(struct panfrost_device *pfdev)
174 {
175 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
176
177 if (pfdevfreq->cooling) {
178 devfreq_cooling_unregister(pfdevfreq->cooling);
179 pfdevfreq->cooling = NULL;
180 }
181 }
182
panfrost_devfreq_resume(struct panfrost_device * pfdev)183 void panfrost_devfreq_resume(struct panfrost_device *pfdev)
184 {
185 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
186
187 if (!pfdevfreq->devfreq)
188 return;
189
190 panfrost_devfreq_reset(pfdevfreq);
191
192 devfreq_resume_device(pfdevfreq->devfreq);
193 }
194
panfrost_devfreq_suspend(struct panfrost_device * pfdev)195 void panfrost_devfreq_suspend(struct panfrost_device *pfdev)
196 {
197 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
198
199 if (!pfdevfreq->devfreq)
200 return;
201
202 devfreq_suspend_device(pfdevfreq->devfreq);
203 }
204
panfrost_devfreq_record_busy(struct panfrost_devfreq * pfdevfreq)205 void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq)
206 {
207 unsigned long irqflags;
208
209 if (!pfdevfreq->devfreq)
210 return;
211
212 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
213
214 panfrost_devfreq_update_utilization(pfdevfreq);
215
216 pfdevfreq->busy_count++;
217
218 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
219 }
220
panfrost_devfreq_record_idle(struct panfrost_devfreq * pfdevfreq)221 void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq)
222 {
223 unsigned long irqflags;
224
225 if (!pfdevfreq->devfreq)
226 return;
227
228 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
229
230 panfrost_devfreq_update_utilization(pfdevfreq);
231
232 WARN_ON(--pfdevfreq->busy_count < 0);
233
234 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
235 }
236