diff options
Diffstat (limited to 'drivers/gpu/drm/panfrost/panfrost_devfreq.c')
| -rw-r--r-- | drivers/gpu/drm/panfrost/panfrost_devfreq.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c new file mode 100644 index 000000000..fe5f12f16 --- /dev/null +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c @@ -0,0 +1,234 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright 2019 Collabora ltd. */ + +#include <linux/clk.h> +#include <linux/devfreq.h> +#include <linux/devfreq_cooling.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> + +#include "panfrost_device.h" +#include "panfrost_devfreq.h" + +static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfreq) +{ + ktime_t now, last; + + now = ktime_get(); + last = pfdevfreq->time_last_update; + + if (pfdevfreq->busy_count > 0) + pfdevfreq->busy_time += ktime_sub(now, last); + else + pfdevfreq->idle_time += ktime_sub(now, last); + + pfdevfreq->time_last_update = now; +} + +static int panfrost_devfreq_target(struct device *dev, unsigned long *freq, + u32 flags) +{ + struct dev_pm_opp *opp; + + opp = devfreq_recommended_opp(dev, freq, flags); + if (IS_ERR(opp)) + return PTR_ERR(opp); + dev_pm_opp_put(opp); + + return dev_pm_opp_set_rate(dev, *freq); +} + +static void panfrost_devfreq_reset(struct panfrost_devfreq *pfdevfreq) +{ + pfdevfreq->busy_time = 0; + pfdevfreq->idle_time = 0; + pfdevfreq->time_last_update = ktime_get(); +} + +static int panfrost_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *status) +{ + struct panfrost_device *pfdev = dev_get_drvdata(dev); + struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; + unsigned long irqflags; + + status->current_frequency = clk_get_rate(pfdev->clock); + + spin_lock_irqsave(&pfdevfreq->lock, irqflags); + + panfrost_devfreq_update_utilization(pfdevfreq); + + status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time, + pfdevfreq->idle_time)); + + status->busy_time = ktime_to_ns(pfdevfreq->busy_time); + + panfrost_devfreq_reset(pfdevfreq); + + spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); + + dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n", + status->busy_time, status->total_time, + status->busy_time / (status->total_time / 100), + status->current_frequency / 1000 / 1000); + + return 0; +} + +static struct devfreq_dev_profile panfrost_devfreq_profile = { + .timer = DEVFREQ_TIMER_DELAYED, + .polling_ms = 50, /* ~3 frames */ + .target = panfrost_devfreq_target, + .get_dev_status = panfrost_devfreq_get_dev_status, +}; + +int panfrost_devfreq_init(struct panfrost_device *pfdev) +{ + int ret; + struct dev_pm_opp *opp; + unsigned long cur_freq; + struct device *dev = &pfdev->pdev->dev; + struct devfreq *devfreq; + struct thermal_cooling_device *cooling; + struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; + + if (pfdev->comp->num_supplies > 1) { + /* + * GPUs with more than 1 supply require platform-specific handling: + * continue without devfreq + */ + DRM_DEV_INFO(dev, "More than 1 supply is not supported yet\n"); + return 0; + } + + ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names); + if (ret) { + /* Continue if the optional regulator is missing */ + if (ret != -ENODEV) { + if (ret != -EPROBE_DEFER) + DRM_DEV_ERROR(dev, "Couldn't set OPP regulators\n"); + return ret; + } + } + + ret = devm_pm_opp_of_add_table(dev); + if (ret) { + /* Optional, continue without devfreq */ + if (ret == -ENODEV) + ret = 0; + return ret; + } + pfdevfreq->opp_of_table_added = true; + + spin_lock_init(&pfdevfreq->lock); + + panfrost_devfreq_reset(pfdevfreq); + + cur_freq = clk_get_rate(pfdev->clock); + + opp = devfreq_recommended_opp(dev, &cur_freq, 0); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + panfrost_devfreq_profile.initial_freq = cur_freq; + + /* + * Set the recommend OPP this will enable and configure the regulator + * if any and will avoid a switch off by regulator_late_cleanup() + */ + ret = dev_pm_opp_set_opp(dev, opp); + if (ret) { + DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n"); + return ret; + } + + dev_pm_opp_put(opp); + + /* + * Setup default thresholds for the simple_ondemand governor. + * The values are chosen based on experiments. + */ + pfdevfreq->gov_data.upthreshold = 45; + pfdevfreq->gov_data.downdifferential = 5; + + devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile, + DEVFREQ_GOV_SIMPLE_ONDEMAND, + &pfdevfreq->gov_data); + if (IS_ERR(devfreq)) { + DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n"); + return PTR_ERR(devfreq); + } + pfdevfreq->devfreq = devfreq; + + cooling = devfreq_cooling_em_register(devfreq, NULL); + if (IS_ERR(cooling)) + DRM_DEV_INFO(dev, "Failed to register cooling device\n"); + else + pfdevfreq->cooling = cooling; + + return 0; +} + +void panfrost_devfreq_fini(struct panfrost_device *pfdev) +{ + struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; + + if (pfdevfreq->cooling) { + devfreq_cooling_unregister(pfdevfreq->cooling); + pfdevfreq->cooling = NULL; + } +} + +void panfrost_devfreq_resume(struct panfrost_device *pfdev) +{ + struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; + + if (!pfdevfreq->devfreq) + return; + + panfrost_devfreq_reset(pfdevfreq); + + devfreq_resume_device(pfdevfreq->devfreq); +} + +void panfrost_devfreq_suspend(struct panfrost_device *pfdev) +{ + struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; + + if (!pfdevfreq->devfreq) + return; + + devfreq_suspend_device(pfdevfreq->devfreq); +} + +void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq) +{ + unsigned long irqflags; + + if (!pfdevfreq->devfreq) + return; + + spin_lock_irqsave(&pfdevfreq->lock, irqflags); + + panfrost_devfreq_update_utilization(pfdevfreq); + + pfdevfreq->busy_count++; + + spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); +} + +void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq) +{ + unsigned long irqflags; + + if (!pfdevfreq->devfreq) + return; + + spin_lock_irqsave(&pfdevfreq->lock, irqflags); + + panfrost_devfreq_update_utilization(pfdevfreq); + + WARN_ON(--pfdevfreq->busy_count < 0); + + spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); +} |