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/platform_device.h> 8 #include <linux/pm_opp.h> 9 10 #include "panfrost_device.h" 11 #include "panfrost_devfreq.h" 12 13 static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfreq) 14 { 15 ktime_t now, last; 16 17 now = ktime_get(); 18 last = pfdevfreq->time_last_update; 19 20 if (pfdevfreq->busy_count > 0) 21 pfdevfreq->busy_time += ktime_sub(now, last); 22 else 23 pfdevfreq->idle_time += ktime_sub(now, last); 24 25 pfdevfreq->time_last_update = now; 26 } 27 28 static int panfrost_devfreq_target(struct device *dev, unsigned long *freq, 29 u32 flags) 30 { 31 struct dev_pm_opp *opp; 32 33 opp = devfreq_recommended_opp(dev, freq, flags); 34 if (IS_ERR(opp)) 35 return PTR_ERR(opp); 36 dev_pm_opp_put(opp); 37 38 return dev_pm_opp_set_rate(dev, *freq); 39 } 40 41 static void panfrost_devfreq_reset(struct panfrost_devfreq *pfdevfreq) 42 { 43 pfdevfreq->busy_time = 0; 44 pfdevfreq->idle_time = 0; 45 pfdevfreq->time_last_update = ktime_get(); 46 } 47 48 static int panfrost_devfreq_get_dev_status(struct device *dev, 49 struct devfreq_dev_status *status) 50 { 51 struct panfrost_device *pfdev = dev_get_drvdata(dev); 52 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; 53 unsigned long irqflags; 54 55 status->current_frequency = clk_get_rate(pfdev->clock); 56 57 spin_lock_irqsave(&pfdevfreq->lock, irqflags); 58 59 panfrost_devfreq_update_utilization(pfdevfreq); 60 61 status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time, 62 pfdevfreq->idle_time)); 63 64 status->busy_time = ktime_to_ns(pfdevfreq->busy_time); 65 66 panfrost_devfreq_reset(pfdevfreq); 67 68 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); 69 70 dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n", 71 status->busy_time, status->total_time, 72 status->busy_time / (status->total_time / 100), 73 status->current_frequency / 1000 / 1000); 74 75 return 0; 76 } 77 78 static struct devfreq_dev_profile panfrost_devfreq_profile = { 79 .timer = DEVFREQ_TIMER_DELAYED, 80 .polling_ms = 50, /* ~3 frames */ 81 .target = panfrost_devfreq_target, 82 .get_dev_status = panfrost_devfreq_get_dev_status, 83 }; 84 85 int panfrost_devfreq_init(struct panfrost_device *pfdev) 86 { 87 int ret; 88 struct dev_pm_opp *opp; 89 unsigned long cur_freq; 90 struct device *dev = &pfdev->pdev->dev; 91 struct devfreq *devfreq; 92 struct opp_table *opp_table; 93 struct thermal_cooling_device *cooling; 94 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; 95 96 opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names, 97 pfdev->comp->num_supplies); 98 if (IS_ERR(opp_table)) { 99 ret = PTR_ERR(opp_table); 100 /* Continue if the optional regulator is missing */ 101 if (ret != -ENODEV) { 102 DRM_DEV_ERROR(dev, "Couldn't set OPP regulators\n"); 103 goto err_fini; 104 } 105 } else { 106 pfdevfreq->regulators_opp_table = opp_table; 107 } 108 109 ret = dev_pm_opp_of_add_table(dev); 110 if (ret) { 111 /* Optional, continue without devfreq */ 112 if (ret == -ENODEV) 113 ret = 0; 114 goto err_fini; 115 } 116 pfdevfreq->opp_of_table_added = true; 117 118 spin_lock_init(&pfdevfreq->lock); 119 120 panfrost_devfreq_reset(pfdevfreq); 121 122 cur_freq = clk_get_rate(pfdev->clock); 123 124 opp = devfreq_recommended_opp(dev, &cur_freq, 0); 125 if (IS_ERR(opp)) { 126 ret = PTR_ERR(opp); 127 goto err_fini; 128 } 129 130 panfrost_devfreq_profile.initial_freq = cur_freq; 131 dev_pm_opp_put(opp); 132 133 /* 134 * Setup default thresholds for the simple_ondemand governor. 135 * The values are chosen based on experiments. 136 */ 137 pfdevfreq->gov_data.upthreshold = 45; 138 pfdevfreq->gov_data.downdifferential = 5; 139 140 devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile, 141 DEVFREQ_GOV_SIMPLE_ONDEMAND, 142 &pfdevfreq->gov_data); 143 if (IS_ERR(devfreq)) { 144 DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n"); 145 ret = PTR_ERR(devfreq); 146 goto err_fini; 147 } 148 pfdevfreq->devfreq = devfreq; 149 150 cooling = devfreq_cooling_em_register(devfreq, NULL); 151 if (IS_ERR(cooling)) 152 DRM_DEV_INFO(dev, "Failed to register cooling device\n"); 153 else 154 pfdevfreq->cooling = cooling; 155 156 return 0; 157 158 err_fini: 159 panfrost_devfreq_fini(pfdev); 160 return ret; 161 } 162 163 void panfrost_devfreq_fini(struct panfrost_device *pfdev) 164 { 165 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; 166 167 if (pfdevfreq->cooling) { 168 devfreq_cooling_unregister(pfdevfreq->cooling); 169 pfdevfreq->cooling = NULL; 170 } 171 172 if (pfdevfreq->opp_of_table_added) { 173 dev_pm_opp_of_remove_table(&pfdev->pdev->dev); 174 pfdevfreq->opp_of_table_added = false; 175 } 176 177 dev_pm_opp_put_regulators(pfdevfreq->regulators_opp_table); 178 pfdevfreq->regulators_opp_table = NULL; 179 } 180 181 void panfrost_devfreq_resume(struct panfrost_device *pfdev) 182 { 183 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; 184 185 if (!pfdevfreq->devfreq) 186 return; 187 188 panfrost_devfreq_reset(pfdevfreq); 189 190 devfreq_resume_device(pfdevfreq->devfreq); 191 } 192 193 void panfrost_devfreq_suspend(struct panfrost_device *pfdev) 194 { 195 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; 196 197 if (!pfdevfreq->devfreq) 198 return; 199 200 devfreq_suspend_device(pfdevfreq->devfreq); 201 } 202 203 void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq) 204 { 205 unsigned long irqflags; 206 207 if (!pfdevfreq->devfreq) 208 return; 209 210 spin_lock_irqsave(&pfdevfreq->lock, irqflags); 211 212 panfrost_devfreq_update_utilization(pfdevfreq); 213 214 pfdevfreq->busy_count++; 215 216 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); 217 } 218 219 void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq) 220 { 221 unsigned long irqflags; 222 223 if (!pfdevfreq->devfreq) 224 return; 225 226 spin_lock_irqsave(&pfdevfreq->lock, irqflags); 227 228 panfrost_devfreq_update_utilization(pfdevfreq); 229 230 WARN_ON(--pfdevfreq->busy_count < 0); 231 232 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); 233 } 234