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path: root/drivers/gpu/drm/panfrost/panfrost_devfreq.c
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Diffstat (limited to 'drivers/gpu/drm/panfrost/panfrost_devfreq.c')
-rw-r--r--drivers/gpu/drm/panfrost/panfrost_devfreq.c234
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);
+}