From ed62d9017801b3b6822b29a5c2a2ac8c4df693e3 Mon Sep 17 00:00:00 2001 From: Sahitya Tummala Date: Mon, 21 Oct 2013 11:27:13 +0530 Subject: [PATCH] PM / devfreq: Add new flag to do simple clock scaling Add new flag "simple_scaling" to on demand governor so that the clocks can be scaled up only when the load is more than up threshold and can be scaled down only when the load is less than down differential data as provided within struct devfreq_simple_ondemand_data. Change-Id: Ibc6ab6297c1b64b6e6eaaa76d735d0b9ae0f6477 Signed-off-by: Sahitya Tummala --- drivers/devfreq/governor_simpleondemand.c | 25 +++++++++++++++++------ include/linux/devfreq.h | 4 ++++ 2 files changed, 23 insertions(+), 6 deletions(-) diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c index bb2936051ccc..d37997da89b1 100644 --- a/drivers/devfreq/governor_simpleondemand.c +++ b/drivers/devfreq/governor_simpleondemand.c @@ -29,6 +29,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL; struct devfreq_simple_ondemand_data *data = df->data; unsigned long max = (df->max_freq) ? df->max_freq : UINT_MAX; + unsigned long min = (df->min_freq) ? df->min_freq : 0; if (err) return err; @@ -43,18 +44,30 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, dfso_upthreshold < dfso_downdifferential) return -EINVAL; - /* Assume MAX if it is going to be divided by zero */ - if (stat.total_time == 0) { - *freq = max; - return 0; - } - /* Prevent overflow */ if (stat.busy_time >= (1 << 24) || stat.total_time >= (1 << 24)) { stat.busy_time >>= 7; stat.total_time >>= 7; } + if (data && data->simple_scaling) { + if (stat.busy_time * 100 > + stat.total_time * dfso_upthreshold) + *freq = max; + else if (stat.busy_time * 100 < + stat.total_time * dfso_downdifferential) + *freq = min; + else + *freq = df->previous_freq; + return 0; + } + + /* Assume MAX if it is going to be divided by zero */ + if (stat.total_time == 0) { + *freq = max; + return 0; + } + /* Set MAX if it's busy enough */ if (stat.busy_time * 100 > stat.total_time * dfso_upthreshold) { diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 7d97c45e7f96..ff0e371aac06 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -228,6 +228,9 @@ extern int devfreq_unregister_opp_notifier(struct device *dev, * the governor may consider slowing the frequency down. * Specify 0 to use the default. Valid value = 0 to 100. * downdifferential < upthreshold must hold. + * @simple_scaling: Setting this flag will scale the clocks up only if the + * load is above @upthreshold and will scale the clocks + * down only if the load is below @downdifferential. * * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor, * the governor uses the default values. @@ -235,6 +238,7 @@ extern int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq_simple_ondemand_data { unsigned int upthreshold; unsigned int downdifferential; + unsigned int simple_scaling; }; #endif