The ACTMON governor is interrupt-driven and currently hardware's polling interval is fixed to 16ms in the driver. Devfreq supports variable polling interval by the generic governors, let's re-use the generic interface for changing of the polling interval. Now the polling interval can be changed dynamically via /sys/class/devfreq/devfreq0/polling_interval.
Signed-off-by: Dmitry Osipenko <[email protected]> --- drivers/devfreq/tegra30-devfreq.c | 71 ++++++++++++++++++++++--------- 1 file changed, 50 insertions(+), 21 deletions(-) diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c index 8adc0ff48b45..e30314bd571a 100644 --- a/drivers/devfreq/tegra30-devfreq.c +++ b/drivers/devfreq/tegra30-devfreq.c @@ -12,6 +12,7 @@ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h> +#include <linux/jiffies.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/platform_device.h> @@ -236,7 +237,7 @@ tegra_actmon_dev_avg_dependency_freq(struct tegra_devfreq *tegra, struct tegra_devfreq_device *dev) { return dev->config->avg_dependency_threshold / - ACTMON_SAMPLING_PERIOD; + tegra->devfreq->profile->polling_ms; } static unsigned long @@ -314,8 +315,8 @@ static void tegra_actmon_get_lower_upper(struct tegra_devfreq *tegra, */ *upper = tegra_actmon_account_cpu_freq(tegra, dev, *upper); - *lower *= ACTMON_SAMPLING_PERIOD; - *upper *= ACTMON_SAMPLING_PERIOD; + *lower *= tegra->devfreq->profile->polling_ms; + *upper *= tegra->devfreq->profile->polling_ms; } static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, @@ -341,8 +342,8 @@ static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, * result, but this one is probably the least churning, although * it may look a bit convoluted. */ - if (freq * ACTMON_SAMPLING_PERIOD > upper) - upper = freq * ACTMON_SAMPLING_PERIOD; + if (freq * tegra->devfreq->profile->polling_ms > upper) + upper = freq * tegra->devfreq->profile->polling_ms; /* * We want to get interrupts when MCCPU client crosses the @@ -420,7 +421,7 @@ static void actmon_isr_device(struct tegra_devfreq *tegra, avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL); - dev->avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; + dev->avg_freq = avg_count / tegra->devfreq->profile->polling_ms; avg_intr_mask = ACTMON_DEV_INTR_AVG_BELOW_WMARK | ACTMON_DEV_INTR_AVG_ABOVE_WMARK; @@ -499,7 +500,7 @@ static unsigned long actmon_update_target(struct tegra_devfreq *tegra, * outdated. */ avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); - avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; + avg_freq = avg_count / tegra->devfreq->profile->polling_ms; old_upper = tegra_actmon_upper_freq(tegra, dev->avg_freq); new_upper = tegra_actmon_upper_freq(tegra, avg_freq); @@ -675,7 +676,7 @@ static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb, * here for too long, otherwise CPUFreq's core will complain with a * warning splat. */ - delay = msecs_to_jiffies(ACTMON_SAMPLING_PERIOD); + delay = msecs_to_jiffies(tegra->devfreq->profile->polling_ms); schedule_delayed_work(&tegra->cpufreq_update_work, delay); return NOTIFY_OK; @@ -690,7 +691,7 @@ static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, dev->boost_freq = 0; dev->avg_freq = clk_get_rate(tegra->emc_clock) / KHZ; - device_writel(dev, dev->avg_freq * ACTMON_SAMPLING_PERIOD, + device_writel(dev, dev->avg_freq * tegra->devfreq->profile->polling_ms, ACTMON_DEV_INIT_AVG); tegra_devfreq_update_avg_wmark(tegra, dev, dev->avg_freq); @@ -725,7 +726,14 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) unsigned int i; int err; - actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, + if (!tegra->devfreq->stop_polling) + return 0; + + tegra->devfreq->previous_freq = clk_get_rate(tegra->emc_clock) / KHZ; + tegra->devfreq->last_stat_updated = jiffies; + tegra->devfreq->stop_polling = false; + + actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1, ACTMON_GLB_PERIOD_CTRL); /* @@ -776,6 +784,11 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) { unsigned int i; + if (tegra->devfreq->stop_polling) + return; + + mutex_unlock(&tegra->devfreq->lock); + disable_irq(tegra->irq); cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb, @@ -783,10 +796,16 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) cancel_delayed_work_sync(&tegra->cpufreq_update_work); + mutex_lock(&tegra->devfreq->lock); + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) tegra_actmon_stop_device(&tegra->devices[i]); clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); + + devfreq_update_status(tegra->devfreq, tegra->devfreq->previous_freq); + + tegra->devfreq->stop_polling = true; } static int tegra_devfreq_target(struct device *dev, unsigned long *freq, @@ -846,7 +865,7 @@ static int tegra_devfreq_get_dev_status(struct device *dev, stat->busy_time *= 100 / BUS_SATURATION_RATIO; /* Number of cycles in a sampling period */ - stat->total_time = cur_freq * ACTMON_SAMPLING_PERIOD; + stat->total_time = cur_freq * tegra->devfreq->profile->polling_ms; stat->busy_time = min(stat->busy_time, stat->total_time); @@ -854,7 +873,7 @@ static int tegra_devfreq_get_dev_status(struct device *dev, } static struct devfreq_dev_profile tegra_devfreq_profile = { - .polling_ms = 0, + .polling_ms = ACTMON_SAMPLING_PERIOD, .target = tegra_devfreq_target, .get_dev_status = tegra_devfreq_get_dev_status, }; @@ -895,8 +914,11 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, unsigned int event, void *data) { struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent); + unsigned int new_delay, *delay_ptr = data; int ret = 0; + mutex_lock(&devfreq->lock); + /* * Couple device with the governor early as it is needed at * the moment of governor's start (used by ISR). @@ -905,26 +927,33 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, switch (event) { case DEVFREQ_GOV_START: - devfreq_monitor_start(devfreq); + devfreq->stop_polling = true; + /* fall through */ + case DEVFREQ_GOV_RESUME: ret = tegra_actmon_start(tegra); break; case DEVFREQ_GOV_STOP: - tegra_actmon_stop(tegra); - devfreq_monitor_stop(devfreq); - break; - + /* fall through */ case DEVFREQ_GOV_SUSPEND: tegra_actmon_stop(tegra); - devfreq_monitor_suspend(devfreq); break; - case DEVFREQ_GOV_RESUME: - devfreq_monitor_resume(devfreq); - ret = tegra_actmon_start(tegra); + case DEVFREQ_GOV_INTERVAL: + new_delay = *delay_ptr; + + if (!new_delay || new_delay > 256) { + ret = -EINVAL; + } else { + tegra_actmon_stop(tegra); + devfreq->profile->polling_ms = new_delay; + ret = tegra_actmon_start(tegra); + } break; } + mutex_unlock(&devfreq->lock); + return ret; } -- 2.22.0
