diff options
Diffstat (limited to 'drivers/gpu/drm/panfrost/panfrost_devfreq.c')
| -rw-r--r-- | drivers/gpu/drm/panfrost/panfrost_devfreq.c | 218 |
1 files changed, 218 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 000000000000..a8121ae67ee3 --- /dev/null +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright 2019 Collabora ltd. */ +#include <linux/devfreq.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/clk.h> +#include <linux/regulator/consumer.h> + +#include "panfrost_device.h" +#include "panfrost_features.h" +#include "panfrost_issues.h" +#include "panfrost_gpu.h" +#include "panfrost_regs.h" + +static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev, int slot); + +static int panfrost_devfreq_target(struct device *dev, unsigned long *freq, + u32 flags) +{ + struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev)); + struct dev_pm_opp *opp; + unsigned long old_clk_rate = pfdev->devfreq.cur_freq; + unsigned long target_volt, target_rate; + int err; + + opp = devfreq_recommended_opp(dev, freq, flags); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + target_rate = dev_pm_opp_get_freq(opp); + target_volt = dev_pm_opp_get_voltage(opp); + dev_pm_opp_put(opp); + + if (old_clk_rate == target_rate) + return 0; + + /* + * If frequency scaling from low to high, adjust voltage first. + * If frequency scaling from high to low, adjust frequency first. + */ + if (old_clk_rate < target_rate) { + err = regulator_set_voltage(pfdev->regulator, target_volt, + target_volt); + if (err) { + dev_err(dev, "Cannot set voltage %lu uV\n", + target_volt); + return err; + } + } + + err = clk_set_rate(pfdev->clock, target_rate); + if (err) { + dev_err(dev, "Cannot set frequency %lu (%d)\n", target_rate, + err); + regulator_set_voltage(pfdev->regulator, pfdev->devfreq.cur_volt, + pfdev->devfreq.cur_volt); + return err; + } + + if (old_clk_rate > target_rate) { + err = regulator_set_voltage(pfdev->regulator, target_volt, + target_volt); + if (err) + dev_err(dev, "Cannot set voltage %lu uV\n", target_volt); + } + + pfdev->devfreq.cur_freq = target_rate; + pfdev->devfreq.cur_volt = target_volt; + + return 0; +} + +static void panfrost_devfreq_reset(struct panfrost_device *pfdev) +{ + ktime_t now = ktime_get(); + int i; + + for (i = 0; i < NUM_JOB_SLOTS; i++) { + pfdev->devfreq.slot[i].busy_time = 0; + pfdev->devfreq.slot[i].idle_time = 0; + pfdev->devfreq.slot[i].time_last_update = now; + } +} + +static int panfrost_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *status) +{ + struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev)); + int i; + + for (i = 0; i < NUM_JOB_SLOTS; i++) { + panfrost_devfreq_update_utilization(pfdev, i); + } + + status->current_frequency = clk_get_rate(pfdev->clock); + status->total_time = ktime_to_ns(ktime_add(pfdev->devfreq.slot[0].busy_time, + pfdev->devfreq.slot[0].idle_time)); + + status->busy_time = 0; + for (i = 0; i < NUM_JOB_SLOTS; i++) { + status->busy_time += ktime_to_ns(pfdev->devfreq.slot[i].busy_time); + } + + /* We're scheduling only to one core atm, so don't divide for now */ + /* status->busy_time /= NUM_JOB_SLOTS; */ + + panfrost_devfreq_reset(pfdev); + + 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 int panfrost_devfreq_get_cur_freq(struct device *dev, unsigned long *freq) +{ + struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev)); + + *freq = pfdev->devfreq.cur_freq; + + return 0; +} + +static struct devfreq_dev_profile panfrost_devfreq_profile = { + .polling_ms = 50, /* ~3 frames */ + .target = panfrost_devfreq_target, + .get_dev_status = panfrost_devfreq_get_dev_status, + .get_cur_freq = panfrost_devfreq_get_cur_freq, +}; + +int panfrost_devfreq_init(struct panfrost_device *pfdev) +{ + int ret; + struct dev_pm_opp *opp; + + if (!pfdev->regulator) + return 0; + + ret = dev_pm_opp_of_add_table(&pfdev->pdev->dev); + if (ret == -ENODEV) /* Optional, continue without devfreq */ + return 0; + + panfrost_devfreq_reset(pfdev); + + pfdev->devfreq.cur_freq = clk_get_rate(pfdev->clock); + + opp = devfreq_recommended_opp(&pfdev->pdev->dev, &pfdev->devfreq.cur_freq, 0); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + panfrost_devfreq_profile.initial_freq = pfdev->devfreq.cur_freq; + dev_pm_opp_put(opp); + + pfdev->devfreq.devfreq = devm_devfreq_add_device(&pfdev->pdev->dev, + &panfrost_devfreq_profile, "simple_ondemand", NULL); + if (IS_ERR(pfdev->devfreq.devfreq)) { + DRM_DEV_ERROR(&pfdev->pdev->dev, "Couldn't initialize GPU devfreq\n"); + ret = PTR_ERR(pfdev->devfreq.devfreq); + pfdev->devfreq.devfreq = NULL; + return ret; + } + + return 0; +} + +void panfrost_devfreq_resume(struct panfrost_device *pfdev) +{ + int i; + + if (!pfdev->devfreq.devfreq) + return; + + panfrost_devfreq_reset(pfdev); + for (i = 0; i < NUM_JOB_SLOTS; i++) + pfdev->devfreq.slot[i].busy = false; + + devfreq_resume_device(pfdev->devfreq.devfreq); +} + +void panfrost_devfreq_suspend(struct panfrost_device *pfdev) +{ + if (!pfdev->devfreq.devfreq) + return; + + devfreq_suspend_device(pfdev->devfreq.devfreq); +} + +static void panfrost_devfreq_update_utilization(struct panfrost_device *pfdev, int slot) +{ + struct panfrost_devfreq_slot *devfreq_slot = &pfdev->devfreq.slot[slot]; + ktime_t now; + ktime_t last; + + if (!pfdev->devfreq.devfreq) + return; + + now = ktime_get(); + last = pfdev->devfreq.slot[slot].time_last_update; + + /* If we last recorded a transition to busy, we have been idle since */ + if (devfreq_slot->busy) + pfdev->devfreq.slot[slot].busy_time += ktime_sub(now, last); + else + pfdev->devfreq.slot[slot].idle_time += ktime_sub(now, last); + + pfdev->devfreq.slot[slot].time_last_update = now; +} + +/* The job scheduler is expected to call this at every transition busy <-> idle */ +void panfrost_devfreq_record_transition(struct panfrost_device *pfdev, int slot) +{ + struct panfrost_devfreq_slot *devfreq_slot = &pfdev->devfreq.slot[slot]; + + panfrost_devfreq_update_utilization(pfdev, slot); + devfreq_slot->busy = !devfreq_slot->busy; +} |