V4L/DVB (11242): allow v4l2 drivers to provide a get_unmapped_area ha…

…ndler Shared memory mappings on nommu machines require a get_unmapped_area file operation that suggests an address for the mapping. This patch adds a way for v4l2 drivers to provide this callback. Signed-off-by: Daniel Glöckner <[email protected]> Signed-off-by: Mauro Carvalho Chehab <[email protected]>
yshchan · Mar 30, 2009 · c01f1a5 · c01f1a5
1 parent 8737f66
commit c01f1a5
Show file tree

Hide file tree

Showing 2 changed files with 21 additions and 0 deletions.
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
@@ -198,6 +198,23 @@ static long v4l2_unlocked_ioctl(struct file *filp,
 	return vdev->fops->unlocked_ioctl(filp, cmd, arg);
 }
 
+#ifdef CONFIG_MMU
+#define v4l2_get_unmapped_area NULL
+#else
+static unsigned long v4l2_get_unmapped_area(struct file *filp,
+		unsigned long addr, unsigned long len, unsigned long pgoff,
+		unsigned long flags)
+{
+	struct video_device *vdev = video_devdata(filp);
+
+	if (!vdev->fops->get_unmapped_area)
+		return -ENOSYS;
+	if (video_is_unregistered(vdev))
+		return -ENODEV;
+	return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
+}
+#endif
+
 static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
 {
 	struct video_device *vdev = video_devdata(filp);
@@ -250,6 +267,7 @@ static const struct file_operations v4l2_unlocked_fops = {
 	.read = v4l2_read,
 	.write = v4l2_write,
 	.open = v4l2_open,
+	.get_unmapped_area = v4l2_get_unmapped_area,
 	.mmap = v4l2_mmap,
 	.unlocked_ioctl = v4l2_unlocked_ioctl,
 #ifdef CONFIG_COMPAT
@@ -265,6 +283,7 @@ static const struct file_operations v4l2_fops = {
 	.read = v4l2_read,
 	.write = v4l2_write,
 	.open = v4l2_open,
+	.get_unmapped_area = v4l2_get_unmapped_area,
 	.mmap = v4l2_mmap,
 	.ioctl = v4l2_ioctl,
 #ifdef CONFIG_COMPAT

diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
@@ -40,6 +40,8 @@ struct v4l2_file_operations {
 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 	long (*ioctl) (struct file *, unsigned int, unsigned long);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
+	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
+				unsigned long, unsigned long, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
 	int (*open) (struct file *);
 	int (*release) (struct file *);