Drivers may need to initialize the video device state with default
values, such as setting a default pixelformat and resolution.
Introduce an optional callback that drivers can populate. The framework
calls this callback during state allocation to allow driver-specific
initialization.
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
--
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Hans Verkuil <hverkuil@kernel.org>
Cc: Ricardo Ribalda <ribalda@chromium.org>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Jai Luthra <jai.luthra@ideasonboard.com>
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ma Ke <make24@iscas.ac.cn>
Cc: linux-media@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
drivers/media/v4l2-core/v4l2-dev.c | 13 +++++++++++++
include/media/v4l2-dev.h | 11 +++++++++++
2 files changed, 24 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index 26b6b2f37ca55ce981aa17a28a875dc3cf253d9b..dff23c6a0b56fb3d29e1c04e386bb445fa8773bb 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -169,6 +169,7 @@ __video_device_state_alloc(struct video_device *vdev,
{
struct video_device_state *state =
kzalloc(sizeof(struct video_device_state), GFP_KERNEL);
+ int ret;
if (!state)
return ERR_PTR(-ENOMEM);
@@ -176,7 +177,19 @@ __video_device_state_alloc(struct video_device *vdev,
state->which = which;
state->vdev = vdev;
+ if (vdev->vdev_ops && vdev->vdev_ops->init_state) {
+ ret = vdev->vdev_ops->init_state(state);
+
+ if (ret)
+ goto err;
+ }
+
return state;
+
+err:
+ kfree(state);
+
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(__video_device_state_alloc);
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 5ca04a1674e0bf7016537e6fb461d790fc0a958f..d327be16f6def70554a7d92d10436a29384ae32a 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -244,6 +244,15 @@ struct video_device_state {
enum video_device_state_whence which;
};
+/**
+ * struct video_device_internal_ops - Callbacks for video device management.
+ *
+ * @init_state: pointer to a function that initializes the video device state.
+ */
+struct video_device_internal_ops {
+ int (*init_state)(struct video_device_state *state);
+};
+
/*
* Newer version of video_device, handled by videodev2.c
* This version moves redundant code from video device code to
@@ -284,6 +293,7 @@ struct video_device_state {
*
* @release: video device release() callback
* @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks
+ * @vdev_ops: pointer to &struct video_device_internal_ops
*
* @valid_ioctls: bitmap with the valid ioctls for this device
* @lock: pointer to &struct mutex serialization lock
@@ -336,6 +346,7 @@ struct video_device {
/* callbacks */
void (*release)(struct video_device *vdev);
const struct v4l2_ioctl_ops *ioctl_ops;
+ const struct video_device_internal_ops *vdev_ops;
DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
struct mutex *lock;
--
2.51.0