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path: root/drivers/media/video/v4l2-dev.c
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Diffstat (limited to 'drivers/media/video/v4l2-dev.c')
-rw-r--r--drivers/media/video/v4l2-dev.c54
1 files changed, 37 insertions, 17 deletions
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 13f87c22e78d..91228b3df07d 100644
--- 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
@@ -288,37 +307,38 @@ static const struct file_operations v4l2_fops = {
*/
static int get_index(struct video_device *vdev, int num)
{
- u32 used = 0;
- const int max_index = sizeof(used) * 8 - 1;
+ /* This can be static since this function is called with the global
+ videodev_lock held. */
+ static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
int i;
- /* Currently a single v4l driver instance cannot create more than
- 32 devices.
- Increase to u64 or an array of u32 if more are needed. */
- if (num > max_index) {
+ if (num >= VIDEO_NUM_DEVICES) {
printk(KERN_ERR "videodev: %s num is too large\n", __func__);
return -EINVAL;
}
- /* Some drivers do not set the parent. In that case always return 0. */
+ /* Some drivers do not set the parent. In that case always return
+ num or 0. */
if (vdev->parent == NULL)
- return 0;
+ return num >= 0 ? num : 0;
+
+ bitmap_zero(used, VIDEO_NUM_DEVICES);
for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
if (video_device[i] != NULL &&
video_device[i]->parent == vdev->parent) {
- used |= 1 << video_device[i]->index;
+ set_bit(video_device[i]->index, used);
}
}
if (num >= 0) {
- if (used & (1 << num))
+ if (test_bit(num, used))
return -ENFILE;
return num;
}
- i = ffz(used);
- return i > max_index ? -ENFILE : i;
+ i = find_first_zero_bit(used, VIDEO_NUM_DEVICES);
+ return i == VIDEO_NUM_DEVICES ? -ENFILE : i;
}
int video_register_device(struct video_device *vdev, int type, int nr)
@@ -365,12 +385,11 @@ int video_register_device_index(struct video_device *vdev, int type, int nr,
/* A minor value of -1 marks this video device as never
having been registered */
- if (vdev)
- vdev->minor = -1;
+ vdev->minor = -1;
/* the release callback MUST be present */
- WARN_ON(!vdev || !vdev->release);
- if (!vdev || !vdev->release)
+ WARN_ON(!vdev->release);
+ if (!vdev->release)
return -EINVAL;
/* Part 1: check device type */
@@ -395,7 +414,7 @@ int video_register_device_index(struct video_device *vdev, int type, int nr,
vdev->vfl_type = type;
vdev->cdev = NULL;
- if (vdev->v4l2_dev)
+ if (vdev->v4l2_dev && vdev->v4l2_dev->dev)
vdev->parent = vdev->v4l2_dev->dev;
/* Part 2: find a free minor, kernel number and device index. */
@@ -582,6 +601,7 @@ module_exit(videodev_exit)
MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
/*