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authorMyungJoo Ham <myungjoo.ham@samsung.com>2011-12-09 16:42:19 +0900
committerMyungJoo Ham <myungjoo.ham@samsung.com>2012-01-20 10:12:38 +0900
commit6530b9dea1b7f33eaf79ba625e3a99f2455f3eb1 (patch)
tree70beddf04779d5941ba6ef851b30e02c7fa0c86c /drivers/devfreq/devfreq.c
parenta95e1f5dbca385908aa4087bb98470b0e0ac58d8 (diff)
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 <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index c189b82f5ec..a129a7b6bfd 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),
{ },
};