V4L/DVB (8787): v4l2-dev: cleanups and add video_drvdata helper function

Cleanup v4l2-dev.[ch], add/improve comments and add a new helper
function: video_drvdata() that can get the private driver data from
a file struct.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index ff219df4b72..1ec0a1a8fb7 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -42,6 +42,7 @@ static ssize_t show_index(struct device *cd,
                          struct device_attribute *attr, char *buf)
 {
         struct video_device *vfd = container_of(cd, struct video_device, dev);
+
         return sprintf(buf, "%i\n", vfd->index);
 }
 
@@ -49,6 +50,7 @@ static ssize_t show_name(struct device *cd,
                          struct device_attribute *attr, char *buf)
 {
         struct video_device *vfd = container_of(cd, struct video_device, dev);
+
         return sprintf(buf, "%.*s\n", (int)sizeof(vfd->name), vfd->name);
 }
 
@@ -60,10 +62,7 @@ static struct device_attribute video_device_attrs[] = {
 
 struct video_device *video_device_alloc(void)
 {
-        struct video_device *vfd;
-
-        vfd = kzalloc(sizeof(*vfd), GFP_KERNEL);
-        return vfd;
+        return kzalloc(sizeof(struct video_device), GFP_KERNEL);
 }
 EXPORT_SYMBOL(video_device_alloc);
 
@@ -263,7 +262,7 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
 
         /* pick a minor number */
         mutex_lock(&videodev_lock);
-        if (nr >= 0  &&  nr < end-base) {
+        if (nr >= 0 && nr < end-base) {
                 /* use the one the driver asked for */
                 i = base + nr;
                 if (NULL != video_device[i]) {
@@ -295,7 +294,7 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
         }
 
         /* sysfs class */
-        memset(&vfd->dev, 0x00, sizeof(vfd->dev));
+        memset(&vfd->dev, 0, sizeof(vfd->dev));
         vfd->dev.class = &video_class;
         vfd->dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
         if (vfd->parent)
@@ -312,8 +311,8 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
 fail_minor:
         mutex_lock(&videodev_lock);
         video_device[vfd->minor] = NULL;
-        vfd->minor = -1;
         mutex_unlock(&videodev_lock);
+        vfd->minor = -1;
         return ret;
 }
 EXPORT_SYMBOL(video_register_device_index);