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-rw-r--r--Documentation/video4linux/v4l2-framework.txt19
1 files changed, 10 insertions, 9 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index eeae76c22a93..ff124374e9ba 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -184,7 +184,7 @@ may be NULL if the subdev driver does not support anything from that category.
184It looks like this: 184It looks like this:
185 185
186struct v4l2_subdev_core_ops { 186struct v4l2_subdev_core_ops {
187 int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_chip_ident *chip); 187 int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip);
188 int (*log_status)(struct v4l2_subdev *sd); 188 int (*log_status)(struct v4l2_subdev *sd);
189 int (*init)(struct v4l2_subdev *sd, u32 val); 189 int (*init)(struct v4l2_subdev *sd, u32 val);
190 ... 190 ...
@@ -390,16 +390,18 @@ allocated memory.
390 390
391You should also set these fields: 391You should also set these fields:
392 392
393- parent: set to the parent device (same device as was used to register 393- v4l2_dev: set to the v4l2_device parent device.
394 v4l2_device).
395- name: set to something descriptive and unique. 394- name: set to something descriptive and unique.
396- fops: set to the file_operations struct. 395- fops: set to the v4l2_file_operations struct.
397- ioctl_ops: if you use the v4l2_ioctl_ops to simplify ioctl maintenance 396- ioctl_ops: if you use the v4l2_ioctl_ops to simplify ioctl maintenance
398 (highly recommended to use this and it might become compulsory in the 397 (highly recommended to use this and it might become compulsory in the
399 future!), then set this to your v4l2_ioctl_ops struct. 398 future!), then set this to your v4l2_ioctl_ops struct.
400 399
401If you use v4l2_ioctl_ops, then you should set .unlocked_ioctl to 400If you use v4l2_ioctl_ops, then you should set either .unlocked_ioctl or
402__video_ioctl2 or .ioctl to video_ioctl2 in your file_operations struct. 401.ioctl to video_ioctl2 in your v4l2_file_operations struct.
402
403The v4l2_file_operations struct is a subset of file_operations. The main
404difference is that the inode argument is omitted since it is never used.
403 405
404 406
405video_device registration 407video_device registration
@@ -410,7 +412,7 @@ for you.
410 412
411 err = video_register_device(vdev, VFL_TYPE_GRABBER, -1); 413 err = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
412 if (err) { 414 if (err) {
413 video_device_release(vdev); // or kfree(my_vdev); 415 video_device_release(vdev); /* or kfree(my_vdev); */
414 return err; 416 return err;
415 } 417 }
416 418
@@ -516,5 +518,4 @@ void *video_drvdata(struct file *file);
516 518
517You can go from a video_device struct to the v4l2_device struct using: 519You can go from a video_device struct to the v4l2_device struct using:
518 520
519struct v4l2_device *v4l2_dev = dev_get_drvdata(vdev->parent); 521struct v4l2_device *v4l2_dev = vdev->v4l2_dev;
520