From 6530b9dea1b7f33eaf79ba625e3a99f2455f3eb1 Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Fri, 9 Dec 2011 16:42:19 +0900 Subject: PM / devfreq: add min/max_freq limit requested by users. The frequency requested to devfreq device driver from devfreq governors is restricted by min_freq and max_freq input. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park --- drivers/devfreq/devfreq.c | 70 +++++++++++++++++++++++++++++++ drivers/devfreq/governor_performance.c | 5 ++- drivers/devfreq/governor_powersave.c | 2 +- drivers/devfreq/governor_simpleondemand.c | 12 ++++-- drivers/devfreq/governor_userspace.c | 15 +++++-- include/linux/devfreq.h | 5 +++ 6 files changed, 101 insertions(+), 8 deletions(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index c189b82f5ece..a129a7b6bfd1 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -501,12 +501,82 @@ static ssize_t show_central_polling(struct device *dev, !to_devfreq(dev)->governor->no_central_polling); } +static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct devfreq *df = to_devfreq(dev); + unsigned long value; + int ret; + unsigned long max; + + ret = sscanf(buf, "%lu", &value); + if (ret != 1) + goto out; + + mutex_lock(&df->lock); + max = df->max_freq; + if (value && max && value > max) { + ret = -EINVAL; + goto unlock; + } + + df->min_freq = value; + update_devfreq(df); + ret = count; +unlock: + mutex_unlock(&df->lock); +out: + return ret; +} + +static ssize_t show_min_freq(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); +} + +static ssize_t store_max_freq(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct devfreq *df = to_devfreq(dev); + unsigned long value; + int ret; + unsigned long min; + + ret = sscanf(buf, "%lu", &value); + if (ret != 1) + goto out; + + mutex_lock(&df->lock); + min = df->min_freq; + if (value && min && value < min) { + ret = -EINVAL; + goto unlock; + } + + df->max_freq = value; + update_devfreq(df); + ret = count; +unlock: + mutex_unlock(&df->lock); +out: + return ret; +} + +static ssize_t show_max_freq(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); +} + static struct device_attribute devfreq_attrs[] = { __ATTR(governor, S_IRUGO, show_governor, NULL), __ATTR(cur_freq, S_IRUGO, show_freq, NULL), __ATTR(central_polling, S_IRUGO, show_central_polling, NULL), __ATTR(polling_interval, S_IRUGO | S_IWUSR, show_polling_interval, store_polling_interval), + __ATTR(min_freq, S_IRUGO | S_IWUSR, show_min_freq, store_min_freq), + __ATTR(max_freq, S_IRUGO | S_IWUSR, show_max_freq, store_max_freq), { }, }; diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c index c0596b291761..574a06b1b1de 100644 --- a/drivers/devfreq/governor_performance.c +++ b/drivers/devfreq/governor_performance.c @@ -18,7 +18,10 @@ static int devfreq_performance_func(struct devfreq *df, * target callback should be able to get floor value as * said in devfreq.h */ - *freq = UINT_MAX; + if (!df->max_freq) + *freq = UINT_MAX; + else + *freq = df->max_freq; return 0; } diff --git a/drivers/devfreq/governor_powersave.c b/drivers/devfreq/governor_powersave.c index 2483a85a266f..d742d4a82d6a 100644 --- a/drivers/devfreq/governor_powersave.c +++ b/drivers/devfreq/governor_powersave.c @@ -18,7 +18,7 @@ static int devfreq_powersave_func(struct devfreq *df, * target callback should be able to get ceiling value as * said in devfreq.h */ - *freq = 0; + *freq = df->min_freq; return 0; } diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c index efad8dcf9028..a2e3eae79011 100644 --- a/drivers/devfreq/governor_simpleondemand.c +++ b/drivers/devfreq/governor_simpleondemand.c @@ -25,6 +25,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD; 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; if (err) return err; @@ -41,7 +42,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, /* Assume MAX if it is going to be divided by zero */ if (stat.total_time == 0) { - *freq = UINT_MAX; + *freq = max; return 0; } @@ -54,13 +55,13 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, /* Set MAX if it's busy enough */ if (stat.busy_time * 100 > stat.total_time * dfso_upthreshold) { - *freq = UINT_MAX; + *freq = max; return 0; } /* Set MAX if we do not know the initial frequency */ if (stat.current_frequency == 0) { - *freq = UINT_MAX; + *freq = max; return 0; } @@ -79,6 +80,11 @@ static int devfreq_simple_ondemand_func(struct devfreq *df, b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2)); *freq = (unsigned long) b; + if (df->min_freq && *freq < df->min_freq) + *freq = df->min_freq; + if (df->max_freq && *freq > df->max_freq) + *freq = df->max_freq; + return 0; } diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c index 4f8b563da782..0681246fc89d 100644 --- a/drivers/devfreq/governor_userspace.c +++ b/drivers/devfreq/governor_userspace.c @@ -25,10 +25,19 @@ static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq) { struct userspace_data *data = df->data; - if (!data->valid) + if (data->valid) { + unsigned long adjusted_freq = data->user_frequency; + + if (df->max_freq && adjusted_freq > df->max_freq) + adjusted_freq = df->max_freq; + + if (df->min_freq && adjusted_freq < df->min_freq) + adjusted_freq = df->min_freq; + + *freq = adjusted_freq; + } else { *freq = df->previous_freq; /* No user freq specified yet */ - else - *freq = data->user_frequency; + } return 0; } diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index f7eb7d06df7e..5862475d05f8 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -124,6 +124,8 @@ struct devfreq_governor { * touch this. * @being_removed a flag to mark that this object is being removed in * order to prevent trying to remove the object multiple times. + * @min_freq Limit minimum frequency requested by user (0: none) + * @max_freq Limit maximum frequency requested by user (0: none) * * This structure stores the devfreq information for a give device. * @@ -149,6 +151,9 @@ struct devfreq { void *data; /* private data for governors */ bool being_removed; + + unsigned long min_freq; + unsigned long max_freq; }; #if defined(CONFIG_PM_DEVFREQ) -- cgit v1.2.3