1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright 2019 Collabora ltd. */ 3 #include <linux/devfreq.h> 4 #include <linux/platform_device.h> 5 #include <linux/pm_opp.h> 6 #include <linux/clk.h> 7 #include <linux/regulator/consumer.h> 8 9 #include "panfrost_device.h" 10 #include "panfrost_devfreq.h" 11 #include "panfrost_features.h" 12 #include "panfrost_issues.h" 13 #include "panfrost_gpu.h" 14 #include "panfrost_regs.h" 15 16 static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev, int slot); 17 18 static int panfrost_devfreq_target(struct device *dev, unsigned long *freq, 19 u32 flags) 20 { 21 struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev)); 22 struct dev_pm_opp *opp; 23 unsigned long old_clk_rate = pfdev->devfreq.cur_freq; 24 unsigned long target_volt, target_rate; 25 int err; 26 27 opp = devfreq_recommended_opp(dev, freq, flags); 28 if (IS_ERR(opp)) 29 return PTR_ERR(opp); 30 31 target_rate = dev_pm_opp_get_freq(opp); 32 target_volt = dev_pm_opp_get_voltage(opp); 33 dev_pm_opp_put(opp); 34 35 if (old_clk_rate == target_rate) 36 return 0; 37 38 /* 39 * If frequency scaling from low to high, adjust voltage first. 40 * If frequency scaling from high to low, adjust frequency first. 41 */ 42 if (old_clk_rate < target_rate) { 43 err = regulator_set_voltage(pfdev->regulator, target_volt, 44 target_volt); 45 if (err) { 46 dev_err(dev, "Cannot set voltage %lu uV\n", 47 target_volt); 48 return err; 49 } 50 } 51 52 err = clk_set_rate(pfdev->clock, target_rate); 53 if (err) { 54 dev_err(dev, "Cannot set frequency %lu (%d)\n", target_rate, 55 err); 56 regulator_set_voltage(pfdev->regulator, pfdev->devfreq.cur_volt, 57 pfdev->devfreq.cur_volt); 58 return err; 59 } 60 61 if (old_clk_rate > target_rate) { 62 err = regulator_set_voltage(pfdev->regulator, target_volt, 63 target_volt); 64 if (err) 65 dev_err(dev, "Cannot set voltage %lu uV\n", target_volt); 66 } 67 68 pfdev->devfreq.cur_freq = target_rate; 69 pfdev->devfreq.cur_volt = target_volt; 70 71 return 0; 72 } 73 74 static void panfrost_devfreq_reset(struct panfrost_device *pfdev) 75 { 76 ktime_t now = ktime_get(); 77 int i; 78 79 for (i = 0; i < NUM_JOB_SLOTS; i++) { 80 pfdev->devfreq.slot[i].busy_time = 0; 81 pfdev->devfreq.slot[i].idle_time = 0; 82 pfdev->devfreq.slot[i].time_last_update = now; 83 } 84 } 85 86 static int panfrost_devfreq_get_dev_status(struct device *dev, 87 struct devfreq_dev_status *status) 88 { 89 struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev)); 90 int i; 91 92 for (i = 0; i < NUM_JOB_SLOTS; i++) { 93 panfrost_devfreq_update_utilization(pfdev, i); 94 } 95 96 status->current_frequency = clk_get_rate(pfdev->clock); 97 status->total_time = ktime_to_ns(ktime_add(pfdev->devfreq.slot[0].busy_time, 98 pfdev->devfreq.slot[0].idle_time)); 99 100 status->busy_time = 0; 101 for (i = 0; i < NUM_JOB_SLOTS; i++) { 102 status->busy_time += ktime_to_ns(pfdev->devfreq.slot[i].busy_time); 103 } 104 105 /* We're scheduling only to one core atm, so don't divide for now */ 106 /* status->busy_time /= NUM_JOB_SLOTS; */ 107 108 panfrost_devfreq_reset(pfdev); 109 110 dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n", status->busy_time, 111 status->total_time, 112 status->busy_time / (status->total_time / 100), 113 status->current_frequency / 1000 / 1000); 114 115 return 0; 116 } 117 118 static int panfrost_devfreq_get_cur_freq(struct device *dev, unsigned long *freq) 119 { 120 struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev)); 121 122 *freq = pfdev->devfreq.cur_freq; 123 124 return 0; 125 } 126 127 static struct devfreq_dev_profile panfrost_devfreq_profile = { 128 .polling_ms = 50, /* ~3 frames */ 129 .target = panfrost_devfreq_target, 130 .get_dev_status = panfrost_devfreq_get_dev_status, 131 .get_cur_freq = panfrost_devfreq_get_cur_freq, 132 }; 133 134 int panfrost_devfreq_init(struct panfrost_device *pfdev) 135 { 136 int ret; 137 struct dev_pm_opp *opp; 138 139 if (!pfdev->regulator) 140 return 0; 141 142 ret = dev_pm_opp_of_add_table(&pfdev->pdev->dev); 143 if (ret == -ENODEV) /* Optional, continue without devfreq */ 144 return 0; 145 else if (ret) 146 return ret; 147 148 panfrost_devfreq_reset(pfdev); 149 150 pfdev->devfreq.cur_freq = clk_get_rate(pfdev->clock); 151 152 opp = devfreq_recommended_opp(&pfdev->pdev->dev, &pfdev->devfreq.cur_freq, 0); 153 if (IS_ERR(opp)) 154 return PTR_ERR(opp); 155 156 panfrost_devfreq_profile.initial_freq = pfdev->devfreq.cur_freq; 157 dev_pm_opp_put(opp); 158 159 pfdev->devfreq.devfreq = devm_devfreq_add_device(&pfdev->pdev->dev, 160 &panfrost_devfreq_profile, "simple_ondemand", NULL); 161 if (IS_ERR(pfdev->devfreq.devfreq)) { 162 DRM_DEV_ERROR(&pfdev->pdev->dev, "Couldn't initialize GPU devfreq\n"); 163 ret = PTR_ERR(pfdev->devfreq.devfreq); 164 pfdev->devfreq.devfreq = NULL; 165 return ret; 166 } 167 168 return 0; 169 } 170 171 void panfrost_devfreq_resume(struct panfrost_device *pfdev) 172 { 173 int i; 174 175 if (!pfdev->devfreq.devfreq) 176 return; 177 178 panfrost_devfreq_reset(pfdev); 179 for (i = 0; i < NUM_JOB_SLOTS; i++) 180 pfdev->devfreq.slot[i].busy = false; 181 182 devfreq_resume_device(pfdev->devfreq.devfreq); 183 } 184 185 void panfrost_devfreq_suspend(struct panfrost_device *pfdev) 186 { 187 if (!pfdev->devfreq.devfreq) 188 return; 189 190 devfreq_suspend_device(pfdev->devfreq.devfreq); 191 } 192 193 static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev, int slot) 194 { 195 struct panfrost_devfreq_slot *devfreq_slot = &pfdev->devfreq.slot[slot]; 196 ktime_t now; 197 ktime_t last; 198 199 if (!pfdev->devfreq.devfreq) 200 return; 201 202 now = ktime_get(); 203 last = pfdev->devfreq.slot[slot].time_last_update; 204 205 /* If we last recorded a transition to busy, we have been idle since */ 206 if (devfreq_slot->busy) 207 pfdev->devfreq.slot[slot].busy_time += ktime_sub(now, last); 208 else 209 pfdev->devfreq.slot[slot].idle_time += ktime_sub(now, last); 210 211 pfdev->devfreq.slot[slot].time_last_update = now; 212 } 213 214 /* The job scheduler is expected to call this at every transition busy <-> idle */ 215 void panfrost_devfreq_record_transition(struct panfrost_device *pfdev, int slot) 216 { 217 struct panfrost_devfreq_slot *devfreq_slot = &pfdev->devfreq.slot[slot]; 218 219 panfrost_devfreq_update_utilization(pfdev, slot); 220 devfreq_slot->busy = !devfreq_slot->busy; 221 } 222