diff options
Diffstat (limited to 'Documentation/video4linux/v4l2-framework.txt')
| -rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index cc350624237..73f9b642392 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -134,7 +134,7 @@ The recommended approach is as follows: static atomic_t drv_instance = ATOMIC_INIT(0); -static int __devinit drv_probe(struct pci_dev *dev, +static int __devinit drv_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id) { ... @@ -218,7 +218,7 @@ to add new ops and categories. A sub-device driver initializes the v4l2_subdev struct using: - v4l2_subdev_init(subdev, &ops); + v4l2_subdev_init(sd, &ops); Afterwards you need to initialize subdev->name with a unique name and set the module owner. This is done for you if you use the i2c helper functions. @@ -226,7 +226,7 @@ module owner. This is done for you if you use the i2c helper functions. A device (bridge) driver needs to register the v4l2_subdev with the v4l2_device: - int err = v4l2_device_register_subdev(device, subdev); + int err = v4l2_device_register_subdev(v4l2_dev, sd); This can fail if the subdev module disappeared before it could be registered. After this function was called successfully the subdev->dev field points to @@ -234,17 +234,17 @@ the v4l2_device. You can unregister a sub-device using: - v4l2_device_unregister_subdev(subdev); + v4l2_device_unregister_subdev(sd); -Afterwards the subdev module can be unloaded and subdev->dev == NULL. +Afterwards the subdev module can be unloaded and sd->dev == NULL. You can call an ops function either directly: - err = subdev->ops->core->g_chip_ident(subdev, &chip); + err = sd->ops->core->g_chip_ident(sd, &chip); but it is better and easier to use this macro: - err = v4l2_subdev_call(subdev, core, g_chip_ident, &chip); + err = v4l2_subdev_call(sd, core, g_chip_ident, &chip); The macro will to the right NULL pointer checks and returns -ENODEV if subdev is NULL, -ENOIOCTLCMD if either subdev->core or subdev->core->g_chip_ident is @@ -252,12 +252,12 @@ NULL, or the actual result of the subdev->ops->core->g_chip_ident ops. It is also possible to call all or a subset of the sub-devices: - v4l2_device_call_all(dev, 0, core, g_chip_ident, &chip); + v4l2_device_call_all(v4l2_dev, 0, core, g_chip_ident, &chip); Any subdev that does not support this ops is skipped and error results are ignored. If you want to check for errors use this: - err = v4l2_device_call_until_err(dev, 0, core, g_chip_ident, &chip); + err = v4l2_device_call_until_err(v4l2_dev, 0, core, g_chip_ident, &chip); Any error except -ENOIOCTLCMD will exit the loop with that error. If no errors (except -ENOIOCTLCMD) occured, then 0 is returned. @@ -505,8 +505,8 @@ There are a few useful helper functions: You can set/get driver private data in the video_device struct using: -void *video_get_drvdata(struct video_device *dev); -void video_set_drvdata(struct video_device *dev, void *data); +void *video_get_drvdata(struct video_device *vdev); +void video_set_drvdata(struct video_device *vdev, void *data); Note that you can safely call video_set_drvdata() before calling video_register_device(). |