drivers/gpu/drm/lima/lima_devfreq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2020 Martin Blumenstingl <[email protected]>
   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 }