Videobuf is a moderately complex API which most V4L2 drivers should use,
but its documentation is...sparse. This document attempts to improve the
situation.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Many drivers access the device number (video_device::v4l2_devnode::num)
in order to print the video device node name. Add and use a helper
function to retrieve the video_device node name.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Warn when the desired device node number is already in use, except when
the new video_register_device_no_warn function is called since in some
use-cases that warning is not relevant.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The term 'kernel number' is very vague, so replace it with the somewhat more
descriptive term 'device node number'.
In one place the local variable 'nr' was used to create the device node number
of the new device name. This has been replaced with the vdev->num field to
more clearly mark this as being the device node number and not the minor
number.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
video_register_device_index is never actually called, instead the
stream index number is always calculated automatically.
This patch removes this function and simplifies the internal get_index
function since that can now always just return the first free index.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Rewrite v4l2_i2c_new_subdev as a simplified version of v4l2_i2c_new_subdev_cfg
and remove v4l2_i2c_new_probed_subdev and v4l2_i2c_new_probed_subdev_addr.
This simplifies this API substantially.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Add a utility function that can be used to setup the v4l2_device's name
field in a standard manner.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The functions v4l2_i2c_new_subdev and v4l2_i2c_new_probed_subdev relied on
i2c_get_adapdata to return the v4l2_device. However, this is not always
possible on embedded platforms. So modify the API to pass the v4l2_device
pointer explicitly.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Now that all drivers are converted to v4l2_subdev we can remove legacy code
in v4l2-common. Also move the documentation of the internal API to
v4l2-subdev.h where it really belongs.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
If usb_interface.dev is used as dev parameter for v4l2_device_register
v4l2_dev.name contains the v4l driver/module name and usb device and
interface instead of a simple "usb x-y".
It also matches the recommendation to set the parent devices for usb
drivers.
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Call v4l2_device_disconnect when the parent of a hotpluggable device
disconnects. This ensures that you do not have a pointer to a device that
is no longer present.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Add a notify callback to v4l2_device to let sub-devices notify their
parent of special events.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Normally the parent device of v4l2_device is used as the video device
node's parent. But if it was not set, then use the parent field in the
video_device struct.
This is needed in the cx88 driver, which has one core v4l2_device but
creates multiple pci devices (one each for raw and mpeg video).
So you cannot associate the core v4l2_device with a particular PCI device,
but you can do that for each video_device.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Emphasize the need to call i2c_set_adapdata and clarify the use of the
chipid in v4l2_i2c_new_(probed_)device().
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Remain consistent in the naming: fields pointing to v4l2_device should
be called v4l2_dev. There are too many device-like entities without
adding to the confusion by mixing naming conventions.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Some drivers (e.g. for ISA devices) have no parent device because there
is no associated bus driver. Allow the parent device to be NULL in
those cases when registering v4l2_device.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Documents the driver usage functions, instead of the generic one used
by the videobuf specific handlers.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Since the i2c driver ID will be removed in the near future we have to
modify the v4l2 debugging API to use the driver name instead of driver ID.
Note that this API is not used in applications other than v4l2-dbg.cpp
as it is for debugging and testing only.
Should anyone use the old VIDIOC_G_CHIP_IDENT, then this will be logged
with a warning that it is deprecated and will be removed in 2.6.30.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Mention the new v4l2_file_operations struct.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Update the documentation now that the v4l2_dev field is in.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
