xref: /openbmc/linux/drivers/gpu/drm/lima/lima_devfreq.c (revision f066af882b3755c5cdd2574e860433750c6bce1e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2020 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
4  *
5  * Based on panfrost_devfreq.c:
6  *   Copyright 2019 Collabora ltd.
7  */
8 #include <linux/clk.h>
9 #include <linux/devfreq.h>
10 #include <linux/devfreq_cooling.h>
11 #include <linux/device.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm_opp.h>
14 #include <linux/property.h>
15 
16 #include "lima_device.h"
17 #include "lima_devfreq.h"
18 
19 static void lima_devfreq_update_utilization(struct lima_devfreq *devfreq)
20 {
21 	ktime_t now, last;
22 
23 	now = ktime_get();
24 	last = devfreq->time_last_update;
25 
26 	if (devfreq->busy_count > 0)
27 		devfreq->busy_time += ktime_sub(now, last);
28 	else
29 		devfreq->idle_time += ktime_sub(now, last);
30 
31 	devfreq->time_last_update = now;
32 }
33 
34 static int lima_devfreq_target(struct device *dev, unsigned long *freq,
35 			       u32 flags)
36 {
37 	struct dev_pm_opp *opp;
38 
39 	opp = devfreq_recommended_opp(dev, freq, flags);
40 	if (IS_ERR(opp))
41 		return PTR_ERR(opp);
42 	dev_pm_opp_put(opp);
43 
44 	return dev_pm_opp_set_rate(dev, *freq);
45 }
46 
47 static void lima_devfreq_reset(struct lima_devfreq *devfreq)
48 {
49 	devfreq->busy_time = 0;
50 	devfreq->idle_time = 0;
51 	devfreq->time_last_update = ktime_get();
52 }
53 
54 static int lima_devfreq_get_dev_status(struct device *dev,
55 				       struct devfreq_dev_status *status)
56 {
57 	struct lima_device *ldev = dev_get_drvdata(dev);
58 	struct lima_devfreq *devfreq = &ldev->devfreq;
59 	unsigned long irqflags;
60 
61 	status->current_frequency = clk_get_rate(ldev->clk_gpu);
62 
63 	spin_lock_irqsave(&devfreq->lock, irqflags);
64 
65 	lima_devfreq_update_utilization(devfreq);
66 
67 	status->total_time = ktime_to_ns(ktime_add(devfreq->busy_time,
68 						   devfreq->idle_time));
69 	status->busy_time = ktime_to_ns(devfreq->busy_time);
70 
71 	lima_devfreq_reset(devfreq);
72 
73 	spin_unlock_irqrestore(&devfreq->lock, irqflags);
74 
75 	dev_dbg(ldev->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 lima_devfreq_profile = {
84 	.timer = DEVFREQ_TIMER_DELAYED,
85 	.polling_ms = 50, /* ~3 frames */
86 	.target = lima_devfreq_target,
87 	.get_dev_status = lima_devfreq_get_dev_status,
88 };
89 
90 void lima_devfreq_fini(struct lima_device *ldev)
91 {
92 	struct lima_devfreq *devfreq = &ldev->devfreq;
93 
94 	if (devfreq->cooling) {
95 		devfreq_cooling_unregister(devfreq->cooling);
96 		devfreq->cooling = NULL;
97 	}
98 
99 	if (devfreq->devfreq) {
100 		devm_devfreq_remove_device(ldev->dev, devfreq->devfreq);
101 		devfreq->devfreq = NULL;
102 	}
103 
104 	dev_pm_opp_of_remove_table(ldev->dev);
105 
106 	dev_pm_opp_put_regulators(devfreq->regulators_opp_table);
107 	dev_pm_opp_put_clkname(devfreq->clkname_opp_table);
108 	devfreq->regulators_opp_table = NULL;
109 	devfreq->clkname_opp_table = NULL;
110 }
111 
112 int lima_devfreq_init(struct lima_device *ldev)
113 {
114 	struct thermal_cooling_device *cooling;
115 	struct device *dev = ldev->dev;
116 	struct opp_table *opp_table;
117 	struct devfreq *devfreq;
118 	struct lima_devfreq *ldevfreq = &ldev->devfreq;
119 	struct dev_pm_opp *opp;
120 	unsigned long cur_freq;
121 	int ret;
122 
123 	if (!device_property_present(dev, "operating-points-v2"))
124 		/* Optional, continue without devfreq */
125 		return 0;
126 
127 	spin_lock_init(&ldevfreq->lock);
128 
129 	opp_table = dev_pm_opp_set_clkname(dev, "core");
130 	if (IS_ERR(opp_table)) {
131 		ret = PTR_ERR(opp_table);
132 		goto err_fini;
133 	}
134 
135 	ldevfreq->clkname_opp_table = opp_table;
136 
137 	opp_table = dev_pm_opp_set_regulators(dev,
138 					      (const char *[]){ "mali" },
139 					      1);
140 	if (IS_ERR(opp_table)) {
141 		ret = PTR_ERR(opp_table);
142 
143 		/* Continue if the optional regulator is missing */
144 		if (ret != -ENODEV)
145 			goto err_fini;
146 	} else {
147 		ldevfreq->regulators_opp_table = opp_table;
148 	}
149 
150 	ret = dev_pm_opp_of_add_table(dev);
151 	if (ret)
152 		goto err_fini;
153 
154 	lima_devfreq_reset(ldevfreq);
155 
156 	cur_freq = clk_get_rate(ldev->clk_gpu);
157 
158 	opp = devfreq_recommended_opp(dev, &cur_freq, 0);
159 	if (IS_ERR(opp)) {
160 		ret = PTR_ERR(opp);
161 		goto err_fini;
162 	}
163 
164 	lima_devfreq_profile.initial_freq = cur_freq;
165 	dev_pm_opp_put(opp);
166 
167 	/*
168 	 * Setup default thresholds for the simple_ondemand governor.
169 	 * The values are chosen based on experiments.
170 	 */
171 	ldevfreq->gov_data.upthreshold = 30;
172 	ldevfreq->gov_data.downdifferential = 5;
173 
174 	devfreq = devm_devfreq_add_device(dev, &lima_devfreq_profile,
175 					  DEVFREQ_GOV_SIMPLE_ONDEMAND,
176 					  &ldevfreq->gov_data);
177 	if (IS_ERR(devfreq)) {
178 		dev_err(dev, "Couldn't initialize GPU devfreq\n");
179 		ret = PTR_ERR(devfreq);
180 		goto err_fini;
181 	}
182 
183 	ldevfreq->devfreq = devfreq;
184 
185 	cooling = of_devfreq_cooling_register(dev->of_node, devfreq);
186 	if (IS_ERR(cooling))
187 		dev_info(dev, "Failed to register cooling device\n");
188 	else
189 		ldevfreq->cooling = cooling;
190 
191 	return 0;
192 
193 err_fini:
194 	lima_devfreq_fini(ldev);
195 	return ret;
196 }
197 
198 void lima_devfreq_record_busy(struct lima_devfreq *devfreq)
199 {
200 	unsigned long irqflags;
201 
202 	if (!devfreq->devfreq)
203 		return;
204 
205 	spin_lock_irqsave(&devfreq->lock, irqflags);
206 
207 	lima_devfreq_update_utilization(devfreq);
208 
209 	devfreq->busy_count++;
210 
211 	spin_unlock_irqrestore(&devfreq->lock, irqflags);
212 }
213 
214 void lima_devfreq_record_idle(struct lima_devfreq *devfreq)
215 {
216 	unsigned long irqflags;
217 
218 	if (!devfreq->devfreq)
219 		return;
220 
221 	spin_lock_irqsave(&devfreq->lock, irqflags);
222 
223 	lima_devfreq_update_utilization(devfreq);
224 
225 	WARN_ON(--devfreq->busy_count < 0);
226 
227 	spin_unlock_irqrestore(&devfreq->lock, irqflags);
228 }
229 
230 int lima_devfreq_resume(struct lima_devfreq *devfreq)
231 {
232 	unsigned long irqflags;
233 
234 	if (!devfreq->devfreq)
235 		return 0;
236 
237 	spin_lock_irqsave(&devfreq->lock, irqflags);
238 
239 	lima_devfreq_reset(devfreq);
240 
241 	spin_unlock_irqrestore(&devfreq->lock, irqflags);
242 
243 	return devfreq_resume_device(devfreq->devfreq);
244 }
245 
246 int lima_devfreq_suspend(struct lima_devfreq *devfreq)
247 {
248 	if (!devfreq->devfreq)
249 		return 0;
250 
251 	return devfreq_suspend_device(devfreq->devfreq);
252 }
253