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(opp))
41		return PTR_ERR(opp);
42	dev_pm_opp_put(opp);
43
44	return dev_pm_opp_set_rate(dev, *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(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
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(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
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, "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, "core");
127	if (ret)
128		return ret;
129
130	ret = devm_pm_opp_set_regulators(dev, 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(ldevfreq);
142
143	cur_freq = clk_get_rate(ldev->clk_gpu);
144
145	opp = devfreq_recommended_opp(dev, &cur_freq, 0);
146	if (IS_ERR(opp))
147		return PTR_ERR(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, &lima_devfreq_profile,
160					  DEVFREQ_GOV_SIMPLE_ONDEMAND,
161					  &ldevfreq->gov_data);
162	if (IS_ERR(devfreq)) {
163		dev_err(dev, "Couldn't initialize GPU devfreq\n");
164		return PTR_ERR(devfreq);
165	}
166
167	ldevfreq->devfreq = devfreq;
168
169	cooling = of_devfreq_cooling_register(dev->of_node, devfreq);
170	if (IS_ERR(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(&devfreq->lock, 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(&devfreq->lock, 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(&devfreq->lock, irqflags);
222
223	return devfreq_resume_device(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);
232}
233