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
19static 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
34static 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(ptr: opp))
41 return PTR_ERR(ptr: opp);
42 dev_pm_opp_put(opp);
43
44 return dev_pm_opp_set_rate(dev, target_freq: *freq);
45}
46
47static 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
54static 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(clk: 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(kt: devfreq->busy_time);
70
71 lima_devfreq_reset(devfreq);
72
73 spin_unlock_irqrestore(lock: &devfreq->lock, flags: 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
83static 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
90void lima_devfreq_fini(struct lima_device *ldev)
91{
92 struct lima_devfreq *devfreq = &ldev->devfreq;
93
94 if (devfreq->cooling) {
95 devfreq_cooling_unregister(dfc: devfreq->cooling);
96 devfreq->cooling = NULL;
97 }
98
99 if (devfreq->devfreq) {
100 devm_devfreq_remove_device(dev: ldev->dev, devfreq: devfreq->devfreq);
101 devfreq->devfreq = NULL;
102 }
103}
104
105int lima_devfreq_init(struct lima_device *ldev)
106{
107 struct thermal_cooling_device *cooling;
108 struct device *dev = ldev->dev;
109 struct devfreq *devfreq;
110 struct lima_devfreq *ldevfreq = &ldev->devfreq;
111 struct dev_pm_opp *opp;
112 unsigned long cur_freq;
113 int ret;
114 const char *regulator_names[] = { "mali", NULL };
115
116 if (!device_property_present(dev, propname: "operating-points-v2"))
117 /* Optional, continue without devfreq */
118 return 0;
119
120 spin_lock_init(&ldevfreq->lock);
121
122 /*
123 * clkname is set separately so it is not affected by the optional
124 * regulator setting which may return error.
125 */
126 ret = devm_pm_opp_set_clkname(dev, name: "core");
127 if (ret)
128 return ret;
129
130 ret = devm_pm_opp_set_regulators(dev, names: regulator_names);
131 if (ret) {
132 /* Continue if the optional regulator is missing */
133 if (ret != -ENODEV)
134 return ret;
135 }
136
137 ret = devm_pm_opp_of_add_table(dev);
138 if (ret)
139 return ret;
140
141 lima_devfreq_reset(devfreq: ldevfreq);
142
143 cur_freq = clk_get_rate(clk: ldev->clk_gpu);
144
145 opp = devfreq_recommended_opp(dev, freq: &cur_freq, flags: 0);
146 if (IS_ERR(ptr: opp))
147 return PTR_ERR(ptr: opp);
148
149 lima_devfreq_profile.initial_freq = cur_freq;
150 dev_pm_opp_put(opp);
151
152 /*
153 * Setup default thresholds for the simple_ondemand governor.
154 * The values are chosen based on experiments.
155 */
156 ldevfreq->gov_data.upthreshold = 30;
157 ldevfreq->gov_data.downdifferential = 5;
158
159 devfreq = devm_devfreq_add_device(dev, profile: &lima_devfreq_profile,
160 DEVFREQ_GOV_SIMPLE_ONDEMAND,
161 data: &ldevfreq->gov_data);
162 if (IS_ERR(ptr: devfreq)) {
163 dev_err(dev, "Couldn't initialize GPU devfreq\n");
164 return PTR_ERR(ptr: devfreq);
165 }
166
167 ldevfreq->devfreq = devfreq;
168
169 cooling = of_devfreq_cooling_register(np: dev->of_node, df: devfreq);
170 if (IS_ERR(ptr: cooling))
171 dev_info(dev, "Failed to register cooling device\n");
172 else
173 ldevfreq->cooling = cooling;
174
175 return 0;
176}
177
178void lima_devfreq_record_busy(struct lima_devfreq *devfreq)
179{
180 unsigned long irqflags;
181
182 if (!devfreq->devfreq)
183 return;
184
185 spin_lock_irqsave(&devfreq->lock, irqflags);
186
187 lima_devfreq_update_utilization(devfreq);
188
189 devfreq->busy_count++;
190
191 spin_unlock_irqrestore(lock: &devfreq->lock, flags: irqflags);
192}
193
194void lima_devfreq_record_idle(struct lima_devfreq *devfreq)
195{
196 unsigned long irqflags;
197
198 if (!devfreq->devfreq)
199 return;
200
201 spin_lock_irqsave(&devfreq->lock, irqflags);
202
203 lima_devfreq_update_utilization(devfreq);
204
205 WARN_ON(--devfreq->busy_count < 0);
206
207 spin_unlock_irqrestore(lock: &devfreq->lock, flags: irqflags);
208}
209
210int lima_devfreq_resume(struct lima_devfreq *devfreq)
211{
212 unsigned long irqflags;
213
214 if (!devfreq->devfreq)
215 return 0;
216
217 spin_lock_irqsave(&devfreq->lock, irqflags);
218
219 lima_devfreq_reset(devfreq);
220
221 spin_unlock_irqrestore(lock: &devfreq->lock, flags: irqflags);
222
223 return devfreq_resume_device(devfreq: devfreq->devfreq);
224}
225
226int lima_devfreq_suspend(struct lima_devfreq *devfreq)
227{
228 if (!devfreq->devfreq)
229 return 0;
230
231 return devfreq_suspend_device(devfreq: devfreq->devfreq);
232}
233

source code of linux/drivers/gpu/drm/lima/lima_devfreq.c