PM / devfreq: Simplify the sysfs name of devfreq-event device

This patch just removes '.' character from the sysfs name of devfreq-event
device as following. Usually, the subsystem uses the similiar naming style
such as {framework name}{Number}.
- old : /sys/class/devfreq-event/event.(X)
- new : /sys/class/devfreq-event/event(X)

And this patch initializes the value of 'event_no' with -1
in order to remove the unneeded operation (-1) when calling
the atomic_inc_return(&event_no).

Lastly, this patch adds the ABI document for devfreq-event class.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/Documentation/ABI/testing/sysfs-class-devfreq-event b/Documentation/ABI/testing/sysfs-class-devfreq-event
new file mode 100644 (file)
index 0000000..ceaf0f6
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-devfreq-event
@@ -0,0 +1,25 @@
+What:          /sys/class/devfreq-event/event(x)/
+Date:          January 2017
+Contact:       Chanwoo Choi <cw00.choi@samsung.com>
+Description:
+               Provide a place in sysfs for the devfreq-event objects.
+               This allows accessing various devfreq-event specific variables.
+               The name of devfreq-event object denoted as 'event(x)' which
+               includes the unique number of 'x' for each devfreq-event object.
+
+What:          /sys/class/devfreq-event/event(x)/name
+Date:          January 2017
+Contact:       Chanwoo Choi <cw00.choi@samsung.com>
+Description:
+               The /sys/class/devfreq-event/event(x)/name attribute contains
+               the name of the devfreq-event object. This attribute is
+               read-only.
+
+What:          /sys/class/devfreq-event/event(x)/enable_count
+Date:          January 2017
+Contact:       Chanwoo Choi <cw00.choi@samsung.com>
+Description:
+               The /sys/class/devfreq-event/event(x)/enable_count attribute
+               contains the reference count to enable the devfreq-event
+               object. If the device is enabled, the value of attribute is
+               greater than zero.

diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
index 9aea2c7ecbe6ec3cba2802502ca54181df0f3935..8648b32ebc8906c123561eaca53af6e48f655a1a 100644 (file)
--- a/drivers/devfreq/devfreq-event.c
+++ b/drivers/devfreq/devfreq-event.c
@@ -306,7 +306,7 @@ struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
                                                struct devfreq_event_desc *desc)
 {
        struct devfreq_event_dev *edev;
-       static atomic_t event_no = ATOMIC_INIT(0);
+       static atomic_t event_no = ATOMIC_INIT(-1);
        int ret;
 
        if (!dev || !desc)
@@ -329,7 +329,7 @@ struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
        edev->dev.class = devfreq_event_class;
        edev->dev.release = devfreq_event_release_edev;
 
-       dev_set_name(&edev->dev, "event.%d", atomic_inc_return(&event_no) - 1);
+       dev_set_name(&edev->dev, "event%d", atomic_inc_return(&event_no));
        ret = device_register(&edev->dev);
        if (ret < 0) {
                put_device(&edev->dev);