Commit f61ee201 authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Chanwoo Choi

PM / devfreq: tegra30: Support variable polling interval

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: default avatarDmitry Osipenko <digetx@gmail.com>
Reviewed-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
parent 5c0f6c79
......@@ -171,6 +171,8 @@ struct tegra_devfreq {
struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];
unsigned int irq;
bool started;
};
struct tegra_actmon_emc_ratio {
......@@ -209,18 +211,26 @@ static void device_writel(struct tegra_devfreq_device *dev, u32 val,
writel_relaxed(val, dev->regs + offset);
}
static unsigned long do_percent(unsigned long val, unsigned int pct)
static unsigned long do_percent(unsigned long long val, unsigned int pct)
{
return val * pct / 100;
val = val * pct;
do_div(val, 100);
/*
* High freq + high boosting percent + large polling interval are
* resulting in integer overflow when watermarks are calculated.
*/
return min_t(u64, val, U32_MAX);
}
static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra,
struct tegra_devfreq_device *dev)
{
u32 avg = dev->avg_count;
u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;
u32 band = avg_band_freq * ACTMON_SAMPLING_PERIOD;
u32 band = avg_band_freq * tegra->devfreq->profile->polling_ms;
u32 avg;
avg = min(dev->avg_count, U32_MAX - band);
device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK);
avg = max(dev->avg_count, band);
......@@ -230,7 +240,7 @@ static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra,
static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,
struct tegra_devfreq_device *dev)
{
u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
u32 val = tegra->cur_freq * tegra->devfreq->profile->polling_ms;
device_writel(dev, do_percent(val, dev->config->boost_up_threshold),
ACTMON_DEV_UPPER_WMARK);
......@@ -309,7 +319,7 @@ static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra,
unsigned int avg_sustain_coef;
unsigned long target_freq;
target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
target_freq = dev->avg_count / tegra->devfreq->profile->polling_ms;
avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
target_freq = do_percent(target_freq, avg_sustain_coef);
......@@ -469,7 +479,7 @@ static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
dev->target_freq = tegra->cur_freq;
dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
dev->avg_count = tegra->cur_freq * tegra->devfreq->profile->polling_ms;
device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG);
tegra_devfreq_update_avg_wmark(tegra, dev);
......@@ -505,12 +515,15 @@ static void tegra_actmon_stop_devices(struct tegra_devfreq *tegra)
}
}
static int tegra_actmon_start(struct tegra_devfreq *tegra)
static int tegra_actmon_resume(struct tegra_devfreq *tegra)
{
unsigned int i;
int err;
actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
if (!tegra->devfreq->profile->polling_ms || !tegra->started)
return 0;
actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1,
ACTMON_GLB_PERIOD_CTRL);
/*
......@@ -558,8 +571,26 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra)
return err;
}
static void tegra_actmon_stop(struct tegra_devfreq *tegra)
static int tegra_actmon_start(struct tegra_devfreq *tegra)
{
int ret = 0;
if (!tegra->started) {
tegra->started = true;
ret = tegra_actmon_resume(tegra);
if (ret)
tegra->started = false;
}
return ret;
}
static void tegra_actmon_pause(struct tegra_devfreq *tegra)
{
if (!tegra->devfreq->profile->polling_ms || !tegra->started)
return;
disable_irq(tegra->irq);
cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb,
......@@ -572,6 +603,12 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb);
}
static void tegra_actmon_stop(struct tegra_devfreq *tegra)
{
tegra_actmon_pause(tegra);
tegra->started = false;
}
static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
u32 flags)
{
......@@ -629,7 +666,7 @@ 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 = ACTMON_SAMPLING_PERIOD * cur_freq;
stat->total_time = tegra->devfreq->profile->polling_ms * cur_freq;
stat->busy_time = min(stat->busy_time, stat->total_time);
......@@ -637,7 +674,7 @@ 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,
};
......@@ -677,6 +714,7 @@ 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 = data;
int ret = 0;
/*
......@@ -696,6 +734,21 @@ static int tegra_governor_event_handler(struct devfreq *devfreq,
devfreq_monitor_stop(devfreq);
break;
case DEVFREQ_GOV_INTERVAL:
/*
* ACTMON hardware supports up to 256 milliseconds for the
* sampling period.
*/
if (*new_delay > 256) {
ret = -EINVAL;
break;
}
tegra_actmon_pause(tegra);
devfreq_interval_update(devfreq, new_delay);
ret = tegra_actmon_resume(tegra);
break;
case DEVFREQ_GOV_SUSPEND:
tegra_actmon_stop(tegra);
devfreq_monitor_suspend(devfreq);
......@@ -715,6 +768,7 @@ static struct devfreq_governor tegra_devfreq_governor = {
.get_target_freq = tegra_governor_get_target,
.event_handler = tegra_governor_event_handler,
.immutable = true,
.interrupt_driven = true,
};
static int tegra_devfreq_probe(struct platform_device *pdev)
......
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