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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/nvmem-consumer.h>
8#include <linux/platform_device.h>
9#include <linux/pm_opp.h>
10
11#include "panfrost_device.h"
12#include "panfrost_devfreq.h"
13
14static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfreq)
15{
16 ktime_t now, last;
17
18 now = ktime_get();
19 last = pfdevfreq->time_last_update;
20
21 if (pfdevfreq->busy_count > 0)
22 pfdevfreq->busy_time += ktime_sub(now, last);
23 else
24 pfdevfreq->idle_time += ktime_sub(now, last);
25
26 pfdevfreq->time_last_update = now;
27}
28
29static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
30 u32 flags)
31{
32 struct panfrost_device *ptdev = dev_get_drvdata(dev);
33 struct dev_pm_opp *opp;
34 int err;
35
36 opp = devfreq_recommended_opp(dev, freq, flags);
37 if (IS_ERR(opp))
38 return PTR_ERR(opp);
39 dev_pm_opp_put(opp);
40
41 err = dev_pm_opp_set_rate(dev, *freq);
42 if (!err)
43 ptdev->pfdevfreq.current_frequency = *freq;
44
45 return err;
46}
47
48static void panfrost_devfreq_reset(struct panfrost_devfreq *pfdevfreq)
49{
50 pfdevfreq->busy_time = 0;
51 pfdevfreq->idle_time = 0;
52 pfdevfreq->time_last_update = ktime_get();
53}
54
55static int panfrost_devfreq_get_dev_status(struct device *dev,
56 struct devfreq_dev_status *status)
57{
58 struct panfrost_device *pfdev = dev_get_drvdata(dev);
59 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
60 unsigned long irqflags;
61
62 status->current_frequency = clk_get_rate(pfdev->clock);
63
64 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
65
66 panfrost_devfreq_update_utilization(pfdevfreq);
67
68 status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time,
69 pfdevfreq->idle_time));
70
71 status->busy_time = ktime_to_ns(pfdevfreq->busy_time);
72
73 panfrost_devfreq_reset(pfdevfreq);
74
75 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
76
77 dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n",
78 status->busy_time, status->total_time,
79 status->busy_time / (status->total_time / 100),
80 status->current_frequency / 1000 / 1000);
81
82 return 0;
83}
84
85static struct devfreq_dev_profile panfrost_devfreq_profile = {
86 .timer = DEVFREQ_TIMER_DELAYED,
87 .polling_ms = 50, /* ~3 frames */
88 .target = panfrost_devfreq_target,
89 .get_dev_status = panfrost_devfreq_get_dev_status,
90};
91
92static int panfrost_read_speedbin(struct device *dev)
93{
94 u32 val;
95 int ret;
96
97 ret = nvmem_cell_read_variable_le_u32(dev, "speed-bin", &val);
98 if (ret) {
99 /*
100 * -ENOENT means that this platform doesn't support speedbins
101 * as it didn't declare any speed-bin nvmem: in this case, we
102 * keep going without it; any other error means that we are
103 * supposed to read the bin value, but we failed doing so.
104 */
105 if (ret != -ENOENT && ret != -EOPNOTSUPP) {
106 DRM_DEV_ERROR(dev, "Cannot read speed-bin (%d).", ret);
107 return ret;
108 }
109
110 return 0;
111 }
112 DRM_DEV_DEBUG(dev, "Using speed-bin = 0x%x\n", val);
113
114 return devm_pm_opp_set_supported_hw(dev, &val, 1);
115}
116
117int panfrost_devfreq_init(struct panfrost_device *pfdev)
118{
119 int ret;
120 struct dev_pm_opp *opp;
121 unsigned long cur_freq;
122 struct device *dev = &pfdev->pdev->dev;
123 struct devfreq *devfreq;
124 struct thermal_cooling_device *cooling;
125 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
126 unsigned long freq = ULONG_MAX;
127
128 if (pfdev->comp->num_supplies > 1) {
129 /*
130 * GPUs with more than 1 supply require platform-specific handling:
131 * continue without devfreq
132 */
133 DRM_DEV_INFO(dev, "More than 1 supply is not supported yet\n");
134 return 0;
135 }
136
137 ret = panfrost_read_speedbin(dev);
138 if (ret)
139 return ret;
140
141 ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names);
142 if (ret) {
143 /* Continue if the optional regulator is missing */
144 if (ret != -ENODEV) {
145 if (ret != -EPROBE_DEFER)
146 DRM_DEV_ERROR(dev, "Couldn't set OPP regulators\n");
147 return ret;
148 }
149 }
150
151 ret = devm_pm_opp_of_add_table(dev);
152 if (ret) {
153 /* Optional, continue without devfreq */
154 if (ret == -ENODEV)
155 ret = 0;
156 return ret;
157 }
158 pfdevfreq->opp_of_table_added = true;
159
160 spin_lock_init(&pfdevfreq->lock);
161
162 panfrost_devfreq_reset(pfdevfreq);
163
164 cur_freq = clk_get_rate(pfdev->clock);
165
166 opp = devfreq_recommended_opp(dev, &cur_freq, 0);
167 if (IS_ERR(opp))
168 return PTR_ERR(opp);
169
170 panfrost_devfreq_profile.initial_freq = cur_freq;
171
172 /*
173 * We could wait until panfrost_devfreq_target() to set this value, but
174 * since the simple_ondemand governor works asynchronously, there's a
175 * chance by the time someone opens the device's fdinfo file, current
176 * frequency hasn't been updated yet, so let's just do an early set.
177 */
178 pfdevfreq->current_frequency = cur_freq;
179
180 /*
181 * Set the recommend OPP this will enable and configure the regulator
182 * if any and will avoid a switch off by regulator_late_cleanup()
183 */
184 ret = dev_pm_opp_set_opp(dev, opp);
185 dev_pm_opp_put(opp);
186 if (ret) {
187 DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
188 return ret;
189 }
190
191 /* Find the fastest defined rate */
192 opp = dev_pm_opp_find_freq_floor(dev, &freq);
193 if (IS_ERR(opp))
194 return PTR_ERR(opp);
195 pfdevfreq->fast_rate = freq;
196
197 dev_pm_opp_put(opp);
198
199 /*
200 * Setup default thresholds for the simple_ondemand governor.
201 * The values are chosen based on experiments.
202 */
203 pfdevfreq->gov_data.upthreshold = 45;
204 pfdevfreq->gov_data.downdifferential = 5;
205
206 devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile,
207 DEVFREQ_GOV_SIMPLE_ONDEMAND,
208 &pfdevfreq->gov_data);
209 if (IS_ERR(devfreq)) {
210 DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n");
211 return PTR_ERR(devfreq);
212 }
213 pfdevfreq->devfreq = devfreq;
214
215 cooling = devfreq_cooling_em_register(devfreq, NULL);
216 if (IS_ERR(cooling))
217 DRM_DEV_INFO(dev, "Failed to register cooling device\n");
218 else
219 pfdevfreq->cooling = cooling;
220
221 return 0;
222}
223
224void panfrost_devfreq_fini(struct panfrost_device *pfdev)
225{
226 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
227
228 if (pfdevfreq->cooling) {
229 devfreq_cooling_unregister(pfdevfreq->cooling);
230 pfdevfreq->cooling = NULL;
231 }
232}
233
234void panfrost_devfreq_resume(struct panfrost_device *pfdev)
235{
236 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
237
238 if (!pfdevfreq->devfreq)
239 return;
240
241 panfrost_devfreq_reset(pfdevfreq);
242
243 devfreq_resume_device(pfdevfreq->devfreq);
244}
245
246void panfrost_devfreq_suspend(struct panfrost_device *pfdev)
247{
248 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
249
250 if (!pfdevfreq->devfreq)
251 return;
252
253 devfreq_suspend_device(pfdevfreq->devfreq);
254}
255
256void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq)
257{
258 unsigned long irqflags;
259
260 if (!pfdevfreq->devfreq)
261 return;
262
263 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
264
265 panfrost_devfreq_update_utilization(pfdevfreq);
266
267 pfdevfreq->busy_count++;
268
269 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
270}
271
272void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq)
273{
274 unsigned long irqflags;
275
276 if (!pfdevfreq->devfreq)
277 return;
278
279 spin_lock_irqsave(&pfdevfreq->lock, irqflags);
280
281 panfrost_devfreq_update_utilization(pfdevfreq);
282
283 WARN_ON(--pfdevfreq->busy_count < 0);
284
285 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);
286}
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright 2019 Collabora ltd. */
3#include <linux/devfreq.h>
4#include <linux/devfreq_cooling.h>
5#include <linux/platform_device.h>
6#include <linux/pm_opp.h>
7#include <linux/clk.h>
8#include <linux/regulator/consumer.h>
9
10#include "panfrost_device.h"
11#include "panfrost_devfreq.h"
12#include "panfrost_features.h"
13#include "panfrost_issues.h"
14#include "panfrost_gpu.h"
15#include "panfrost_regs.h"
16
17static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev);
18
19static int panfrost_devfreq_target(struct device *dev, unsigned long *freq,
20 u32 flags)
21{
22 struct dev_pm_opp *opp;
23 int err;
24
25 opp = devfreq_recommended_opp(dev, freq, flags);
26 if (IS_ERR(opp))
27 return PTR_ERR(opp);
28 dev_pm_opp_put(opp);
29
30 err = dev_pm_opp_set_rate(dev, *freq);
31 if (err)
32 return err;
33
34 return 0;
35}
36
37static void panfrost_devfreq_reset(struct panfrost_device *pfdev)
38{
39 pfdev->devfreq.busy_time = 0;
40 pfdev->devfreq.idle_time = 0;
41 pfdev->devfreq.time_last_update = ktime_get();
42}
43
44static int panfrost_devfreq_get_dev_status(struct device *dev,
45 struct devfreq_dev_status *status)
46{
47 struct panfrost_device *pfdev = dev_get_drvdata(dev);
48
49 panfrost_devfreq_update_utilization(pfdev);
50
51 status->current_frequency = clk_get_rate(pfdev->clock);
52 status->total_time = ktime_to_ns(ktime_add(pfdev->devfreq.busy_time,
53 pfdev->devfreq.idle_time));
54
55 status->busy_time = ktime_to_ns(pfdev->devfreq.busy_time);
56
57 panfrost_devfreq_reset(pfdev);
58
59 dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n", status->busy_time,
60 status->total_time,
61 status->busy_time / (status->total_time / 100),
62 status->current_frequency / 1000 / 1000);
63
64 return 0;
65}
66
67static struct devfreq_dev_profile panfrost_devfreq_profile = {
68 .polling_ms = 50, /* ~3 frames */
69 .target = panfrost_devfreq_target,
70 .get_dev_status = panfrost_devfreq_get_dev_status,
71};
72
73int panfrost_devfreq_init(struct panfrost_device *pfdev)
74{
75 int ret;
76 struct dev_pm_opp *opp;
77 unsigned long cur_freq;
78 struct device *dev = &pfdev->pdev->dev;
79 struct devfreq *devfreq;
80 struct thermal_cooling_device *cooling;
81
82 ret = dev_pm_opp_of_add_table(dev);
83 if (ret == -ENODEV) /* Optional, continue without devfreq */
84 return 0;
85 else if (ret)
86 return ret;
87
88 panfrost_devfreq_reset(pfdev);
89
90 cur_freq = clk_get_rate(pfdev->clock);
91
92 opp = devfreq_recommended_opp(dev, &cur_freq, 0);
93 if (IS_ERR(opp))
94 return PTR_ERR(opp);
95
96 panfrost_devfreq_profile.initial_freq = cur_freq;
97 dev_pm_opp_put(opp);
98
99 devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile,
100 DEVFREQ_GOV_SIMPLE_ONDEMAND, NULL);
101 if (IS_ERR(devfreq)) {
102 DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n");
103 dev_pm_opp_of_remove_table(dev);
104 return PTR_ERR(devfreq);
105 }
106 pfdev->devfreq.devfreq = devfreq;
107
108 cooling = of_devfreq_cooling_register(dev->of_node, devfreq);
109 if (IS_ERR(cooling))
110 DRM_DEV_INFO(dev, "Failed to register cooling device\n");
111 else
112 pfdev->devfreq.cooling = cooling;
113
114 return 0;
115}
116
117void panfrost_devfreq_fini(struct panfrost_device *pfdev)
118{
119 if (pfdev->devfreq.cooling)
120 devfreq_cooling_unregister(pfdev->devfreq.cooling);
121 dev_pm_opp_of_remove_table(&pfdev->pdev->dev);
122}
123
124void panfrost_devfreq_resume(struct panfrost_device *pfdev)
125{
126 if (!pfdev->devfreq.devfreq)
127 return;
128
129 panfrost_devfreq_reset(pfdev);
130
131 devfreq_resume_device(pfdev->devfreq.devfreq);
132}
133
134void panfrost_devfreq_suspend(struct panfrost_device *pfdev)
135{
136 if (!pfdev->devfreq.devfreq)
137 return;
138
139 devfreq_suspend_device(pfdev->devfreq.devfreq);
140}
141
142static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev)
143{
144 ktime_t now;
145 ktime_t last;
146
147 if (!pfdev->devfreq.devfreq)
148 return;
149
150 now = ktime_get();
151 last = pfdev->devfreq.time_last_update;
152
153 if (atomic_read(&pfdev->devfreq.busy_count) > 0)
154 pfdev->devfreq.busy_time += ktime_sub(now, last);
155 else
156 pfdev->devfreq.idle_time += ktime_sub(now, last);
157
158 pfdev->devfreq.time_last_update = now;
159}
160
161void panfrost_devfreq_record_busy(struct panfrost_device *pfdev)
162{
163 panfrost_devfreq_update_utilization(pfdev);
164 atomic_inc(&pfdev->devfreq.busy_count);
165}
166
167void panfrost_devfreq_record_idle(struct panfrost_device *pfdev)
168{
169 int count;
170
171 panfrost_devfreq_update_utilization(pfdev);
172 count = atomic_dec_if_positive(&pfdev->devfreq.busy_count);
173 WARN_ON(count < 0);
174}