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1// SPDX-License-Identifier: GPL-2.02/* 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 else24 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 speedbins101 * as it didn't declare any speed-bin nvmem: in this case, we102 * keep going without it; any other error means that we are103 * 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 devfreq132 */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, but174 * since the simple_ondemand governor works asynchronously, there's a175 * chance by the time someone opens the device's fdinfo file, current176 * 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 regulator182 * if any and will avoid a switch off by regulator_late_cleanup()183 */184 ret = dev_pm_opp_set_opp(dev, opp);185 if (ret) {186 DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");187 return ret;188 }189 190 /* Find the fastest defined rate */191 opp = dev_pm_opp_find_freq_floor(dev, &freq);192 if (IS_ERR(opp))193 return PTR_ERR(opp);194 pfdevfreq->fast_rate = freq;195 196 dev_pm_opp_put(opp);197 198 /*199 * Setup default thresholds for the simple_ondemand governor.200 * The values are chosen based on experiments.201 */202 pfdevfreq->gov_data.upthreshold = 45;203 pfdevfreq->gov_data.downdifferential = 5;204 205 devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile,206 DEVFREQ_GOV_SIMPLE_ONDEMAND,207 &pfdevfreq->gov_data);208 if (IS_ERR(devfreq)) {209 DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n");210 return PTR_ERR(devfreq);211 }212 pfdevfreq->devfreq = devfreq;213 214 cooling = devfreq_cooling_em_register(devfreq, NULL);215 if (IS_ERR(cooling))216 DRM_DEV_INFO(dev, "Failed to register cooling device\n");217 else218 pfdevfreq->cooling = cooling;219 220 return 0;221}222 223void panfrost_devfreq_fini(struct panfrost_device *pfdev)224{225 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;226 227 if (pfdevfreq->cooling) {228 devfreq_cooling_unregister(pfdevfreq->cooling);229 pfdevfreq->cooling = NULL;230 }231}232 233void panfrost_devfreq_resume(struct panfrost_device *pfdev)234{235 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;236 237 if (!pfdevfreq->devfreq)238 return;239 240 panfrost_devfreq_reset(pfdevfreq);241 242 devfreq_resume_device(pfdevfreq->devfreq);243}244 245void panfrost_devfreq_suspend(struct panfrost_device *pfdev)246{247 struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;248 249 if (!pfdevfreq->devfreq)250 return;251 252 devfreq_suspend_device(pfdevfreq->devfreq);253}254 255void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq)256{257 unsigned long irqflags;258 259 if (!pfdevfreq->devfreq)260 return;261 262 spin_lock_irqsave(&pfdevfreq->lock, irqflags);263 264 panfrost_devfreq_update_utilization(pfdevfreq);265 266 pfdevfreq->busy_count++;267 268 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);269}270 271void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq)272{273 unsigned long irqflags;274 275 if (!pfdevfreq->devfreq)276 return;277 278 spin_lock_irqsave(&pfdevfreq->lock, irqflags);279 280 panfrost_devfreq_update_utilization(pfdevfreq);281 282 WARN_ON(--pfdevfreq->busy_count < 0);283 284 spin_unlock_irqrestore(&pfdevfreq->lock, irqflags);285}286