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authorMyungJoo Ham <myungjoo.ham@samsung.com>2011-10-02 02:19:28 +0400
committerRafael J. Wysocki <rjw@sisk.pl>2011-10-02 02:19:28 +0400
commit9005b65099ee4f14b6be691c4574612fe947531a (patch)
tree5066aa8189dd6614d3418b56a9483db0f8a57aa2 /drivers/devfreq/devfreq.c
parenta3c98b8b2ede1f4230f49f9af7135cd902e71e83 (diff)
downloadlinux-9005b65099ee4f14b6be691c4574612fe947531a.tar.xz
PM / devfreq: Add common sysfs interfaces
Device specific sysfs interface /sys/devices/.../power/devfreq_* - governor R: name of governor - cur_freq R: current frequency - polling_interval R: polling interval in ms given with devfreq profile W: update polling interval. - central_polling R: 1 if polling is managed by devfreq framework Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mike Turquette <mturquette@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> -- Documentation/ABI/testing/sysfs-class-devfreq | 44 ++++++++++++++++ drivers/devfreq/devfreq.c | 69 ++++++++++++++++++++++++++ 2 files changed, 113 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-devfreq
Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index f3100b19f798..5d15b812377b 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -437,6 +437,74 @@ int devfreq_remove_device(struct devfreq *devfreq)
return 0;
}
+static ssize_t show_governor(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name);
+}
+
+static ssize_t show_freq(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
+}
+
+static ssize_t show_polling_interval(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms);
+}
+
+static ssize_t store_polling_interval(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct devfreq *df = to_devfreq(dev);
+ unsigned int value;
+ int ret;
+
+ ret = sscanf(buf, "%u", &value);
+ if (ret != 1)
+ goto out;
+
+ mutex_lock(&df->lock);
+ df->profile->polling_ms = value;
+ df->next_polling = df->polling_jiffies
+ = msecs_to_jiffies(value);
+ mutex_unlock(&df->lock);
+
+ ret = count;
+
+ if (df->governor->no_central_polling)
+ goto out;
+
+ mutex_lock(&devfreq_list_lock);
+ if (df->next_polling > 0 && !polling) {
+ polling = true;
+ queue_delayed_work(devfreq_wq, &devfreq_work,
+ df->next_polling);
+ }
+ mutex_unlock(&devfreq_list_lock);
+out:
+ return ret;
+}
+
+static ssize_t show_central_polling(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n",
+ !to_devfreq(dev)->governor->no_central_polling);
+}
+
+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),
+ { },
+};
+
/**
* devfreq_start_polling() - Initialize data structure for devfreq framework and
* start polling registered devfreq devices.
@@ -461,6 +529,7 @@ static int __init devfreq_init(void)
pr_err("%s: couldn't create class\n", __FILE__);
return PTR_ERR(devfreq_class);
}
+ devfreq_class->dev_attrs = devfreq_attrs;
return 0;
}
subsys_initcall(devfreq_init);