1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2019 Collabora ltd. */
5 #include <linux/devfreq.h>
6 #include <linux/devfreq_cooling.h>
7 #include <linux/platform_device.h>
8 #include <linux/pm_opp.h>
10 #include "panfrost_device.h"
11 #include "panfrost_devfreq.h"
13 static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfreq)
18 last = pfdevfreq->time_last_update;
20 if (pfdevfreq->busy_count > 0)
21 pfdevfreq->busy_time += ktime_sub(now, last);
23 pfdevfreq->idle_time += ktime_sub(now, last);
25 pfdevfreq->time_last_update = now;
28 static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
31 struct dev_pm_opp *opp;
33 opp = devfreq_recommended_opp(dev, freq, flags);
38 return dev_pm_opp_set_rate(dev, *freq);
41 static void panfrost_devfreq_reset(struct panfrost_devfreq *pfdevfreq)
43 pfdevfreq->busy_time = 0;
44 pfdevfreq->idle_time = 0;
45 pfdevfreq->time_last_update = ktime_get();
48 static int panfrost_devfreq_get_dev_status(struct device *dev,
49 struct devfreq_dev_status *status)
51 struct panfrost_device *pfdev = dev_get_drvdata(dev);
52 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
53 unsigned long irqflags;
55 status->current_frequency = clk_get_rate(pfdev->clock);
57 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
59 panfrost_devfreq_update_utilization(pfdevfreq);
61 status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time,
62 pfdevfreq->idle_time));
64 status->busy_time = ktime_to_ns(pfdevfreq->busy_time);
66 panfrost_devfreq_reset(pfdevfreq);
68 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
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);
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,
85 int panfrost_devfreq_init(struct panfrost_device *pfdev)
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;
95 if (pfdev->comp->num_supplies > 1) {
97 * GPUs with more than 1 supply require platform-specific handling:
98 * continue without devfreq
100 DRM_DEV_INFO(dev, "More than 1 supply is not supported yet\n");
104 ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
105 pfdev->comp->num_supplies);
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");
115 ret = devm_pm_opp_of_add_table(dev);
117 /* Optional, continue without devfreq */
122 pfdevfreq->opp_of_table_added = true;
124 spin_lock_init(&pfdevfreq->lock);
126 panfrost_devfreq_reset(pfdevfreq);
128 cur_freq = clk_get_rate(pfdev->clock);
130 opp = devfreq_recommended_opp(dev, &cur_freq, 0);
134 panfrost_devfreq_profile.initial_freq = cur_freq;
138 * Setup default thresholds for the simple_ondemand governor.
139 * The values are chosen based on experiments.
141 pfdevfreq->gov_data.upthreshold = 45;
142 pfdevfreq->gov_data.downdifferential = 5;
144 devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile,
145 DEVFREQ_GOV_SIMPLE_ONDEMAND,
146 &pfdevfreq->gov_data);
147 if (IS_ERR(devfreq)) {
148 DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n");
149 return PTR_ERR(devfreq);
151 pfdevfreq->devfreq = devfreq;
153 cooling = devfreq_cooling_em_register(devfreq, NULL);
155 DRM_DEV_INFO(dev, "Failed to register cooling device\n");
157 pfdevfreq->cooling = cooling;
162 void panfrost_devfreq_fini(struct panfrost_device *pfdev)
164 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
166 if (pfdevfreq->cooling) {
167 devfreq_cooling_unregister(pfdevfreq->cooling);
168 pfdevfreq->cooling = NULL;
172 void panfrost_devfreq_resume(struct panfrost_device *pfdev)
174 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
176 if (!pfdevfreq->devfreq)
179 panfrost_devfreq_reset(pfdevfreq);
181 devfreq_resume_device(pfdevfreq->devfreq);
184 void panfrost_devfreq_suspend(struct panfrost_device *pfdev)
186 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
188 if (!pfdevfreq->devfreq)
191 devfreq_suspend_device(pfdevfreq->devfreq);
194 void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq)
196 unsigned long irqflags;
198 if (!pfdevfreq->devfreq)
201 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
203 panfrost_devfreq_update_utilization(pfdevfreq);
205 pfdevfreq->busy_count++;
207 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
210 void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq)
212 unsigned long irqflags;
214 if (!pfdevfreq->devfreq)
217 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
219 panfrost_devfreq_update_utilization(pfdevfreq);
221 WARN_ON(--pfdevfreq->busy_count < 0);
223 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);