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 <digetx@xxxxxxxxx>
---
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
