1 .. -*- coding: utf-8; mode: rst -*-
3 .. _media_ioc_device_info:
5 ***************************
6 ioctl MEDIA_IOC_DEVICE_INFO
7 ***************************
12 MEDIA_IOC_DEVICE_INFO - Query device information
18 .. c:function:: int ioctl( int fd, MEDIA_IOC_DEVICE_INFO, struct media_device_info *argp )
19 :name: MEDIA_IOC_DEVICE_INFO
26 File descriptor returned by :ref:`open() <media-func-open>`.
34 All media devices must support the ``MEDIA_IOC_DEVICE_INFO`` ioctl. To
35 query device information, applications call the ioctl with a pointer to
36 a struct :c:type:`media_device_info`. The driver
37 fills the structure and returns the information to the application. The
41 .. c:type:: media_device_info
43 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
45 .. flat-table:: struct media_device_info
53 - Name of the driver implementing the media API as a NUL-terminated
54 ASCII string. The driver version is stored in the
55 ``driver_version`` field.
57 Driver specific applications can use this information to verify
58 the driver identity. It is also useful to work around known bugs,
59 or to identify drivers in error reports.
63 - Device model name as a NUL-terminated UTF-8 string. The device
64 version is stored in the ``device_version`` field and is not be
65 appended to the model name.
69 - Serial number as a NUL-terminated ASCII string.
73 - Location of the device in the system as a NUL-terminated ASCII
74 string. This includes the bus type name (PCI, USB, ...) and a
75 bus-specific identifier.
79 - Media API version, formatted with the ``KERNEL_VERSION()`` macro.
83 - Hardware device revision in a driver-specific format.
87 - Media device driver version, formatted with the
88 ``KERNEL_VERSION()`` macro. Together with the ``driver`` field
89 this identifies a particular driver.
93 - Reserved for future extensions. Drivers and applications must set
97 The ``serial`` and ``bus_info`` fields can be used to distinguish
98 between multiple instances of otherwise identical hardware. The serial
99 number takes precedence when provided and can be assumed to be unique.
100 If the serial number is an empty string, the ``bus_info`` field can be
101 used instead. The ``bus_info`` field is guaranteed to be unique, but can
102 vary across reboots or device unplug/replug.
108 On success 0 is returned, on error -1 and the ``errno`` variable is set
109 appropriately. The generic error codes are described at the
110 :ref:`Generic Error Codes <gen-errors>` chapter.