Add two new functions: v4l2_fh_open allocates and initializes a struct v4l2_fh
based on a struct file pointer and v4l2_fh_release releases and frees a struct
v4l2_fh.
These functions are also called if the v4l2_file_operations struct provides
neither open nor release functions.
Signed-off-by: Hans Verkuil <hverkuil@xxxxxxxxx>
---
drivers/media/video/v4l2-dev.c | 19 +++++++++++++++----
drivers/media/video/v4l2-fh.c | 26 ++++++++++++++++++++++++++
include/media/v4l2-fh.h | 16 ++++++++++++++++
3 files changed, 57 insertions(+), 4 deletions(-)
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index c8f6ae1..e4fe644 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -31,6 +31,7 @@
#include <media/v4l2-common.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
+#include <media/v4l2-fh.h>
#define VIDEO_NUM_DEVICES 256
#define VIDEO_NAME "video4linux"
@@ -367,6 +368,7 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
static int v4l2_open(struct inode *inode, struct file *filp)
{
struct video_device *vdev;
+ int (*open)(struct file *);
int ret = 0;
/* Check if the video device is available */
@@ -380,13 +382,17 @@ static int v4l2_open(struct inode *inode, struct file *filp)
/* and increase the device refcount */
video_get(vdev);
mutex_unlock(&videodev_lock);
- if (vdev->fops->open) {
+ if (vdev->fops->open)
+ open = vdev->fops->open;
+ else if (!vdev->fops->release)
+ open = v4l2_fh_open;
+ if (open) {
if (vdev->lock && mutex_lock_interruptible(vdev->lock)) {
ret = -ERESTARTSYS;
goto err;
}
if (video_is_registered(vdev))
- ret = vdev->fops->open(filp);
+ ret = open(filp);
else
ret = -ENODEV;
if (vdev->lock)
@@ -404,12 +410,17 @@ err:
static int v4l2_release(struct inode *inode, struct file *filp)
{
struct video_device *vdev = video_devdata(filp);
+ int (*release)(struct file *);
int ret = 0;
- if (vdev->fops->release) {
+ if (vdev->fops->release)
+ release = vdev->fops->release;
+ else if (!vdev->fops->open)
+ release = v4l2_fh_release;
+ if (release) {
if (vdev->lock)
mutex_lock(vdev->lock);
- vdev->fops->release(filp);
+ release(filp);
if (vdev->lock)
mutex_unlock(vdev->lock);
}
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
index 78a1608..133c68d 100644
--- a/drivers/media/video/v4l2-fh.c
+++ b/drivers/media/video/v4l2-fh.c
@@ -23,6 +23,7 @@
*/
#include <linux/bitops.h>
+#include <linux/slab.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
@@ -60,6 +61,20 @@ void v4l2_fh_add(struct v4l2_fh *fh)
}
EXPORT_SYMBOL_GPL(v4l2_fh_add);
+int v4l2_fh_open(struct file *filp)
+{
+ struct video_device *vdev = video_devdata(filp);
+ struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
+
+ if (fh == NULL)
+ return -ENOMEM;
+ filp->private_data = fh;
+ v4l2_fh_init(fh, vdev);
+ v4l2_fh_add(fh);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_fh_open);
+
void v4l2_fh_del(struct v4l2_fh *fh)
{
unsigned long flags;
@@ -81,3 +96,14 @@ void v4l2_fh_exit(struct v4l2_fh *fh)
v4l2_event_free(fh);
}
EXPORT_SYMBOL_GPL(v4l2_fh_exit);
+
+int v4l2_fh_release(struct file *filp)
+{
+ struct v4l2_fh *fh = filp->private_data;
+
+ v4l2_fh_del(fh);
+ v4l2_fh_exit(fh);
+ kfree(fh);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_fh_release);
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
index 5fc5ba9..e80a101 100644
--- a/include/media/v4l2-fh.h
+++ b/include/media/v4l2-fh.h
@@ -51,8 +51,16 @@ int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
*/
void v4l2_fh_add(struct v4l2_fh *fh);
/*
+ * Can be used as the open() op of v4l2_file_operations.
+ * It allocates a v4l2_fh and inits and adds it to the video_device associated
+ * with the file pointer.
+ */
+int v4l2_fh_open(struct file *filp);
+/*
* Remove file handle from the list of file handles. Must be called in
* v4l2_file_operations->release() handler if the driver uses v4l2_fh.
+ * The core will call this also if neither open() nor release() was
+ * specified in v4l2_file_operations.
*/
void v4l2_fh_del(struct v4l2_fh *fh);
/*
@@ -62,5 +70,13 @@ void v4l2_fh_del(struct v4l2_fh *fh);
* driver uses v4l2_fh.
*/
void v4l2_fh_exit(struct v4l2_fh *fh);
+/*
+ * Can be used as the release() op of v4l2_file_operations.
+ * It deletes and exits the v4l2_fh associated with the file pointer and
+ * frees it.
+ * The core will call this also if neither open() nor release() was
+ * specified in v4l2_file_operations.
+ */
+int v4l2_fh_release(struct file *filp);
#endif /* V4L2_EVENT_H */
--
1.7.0.4
--
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