MEDIA_IOC_DEVICE_INFO — Query device information


int ioctl(int fd,
 int request,
 struct media_device_info *argp);



File descriptor returned by open().





All media devices must support the MEDIA_IOC_DEVICE_INFO ioctl. To query device information, applications call the ioctl with a pointer to a struct media_device_info. The driver fills the structure and returns the information to the application. The ioctl never fails.

Table L.1. struct media_device_info


Name of the driver implementing the media API as a NUL-terminated ASCII string. The driver version is stored in the driver_version field.

Driver specific applications can use this information to verify the driver identity. It is also useful to work around known bugs, or to identify drivers in error reports.

charmodel[32]Device model name as a NUL-terminated UTF-8 string. The device version is stored in the device_version field and is not be appended to the model name.
charserial[40]Serial number as a NUL-terminated ASCII string.
charbus_info[32]Location of the device in the system as a NUL-terminated ASCII string. This includes the bus type name (PCI, USB, ...) and a bus-specific identifier.
__u32media_versionMedia API version, formatted with the KERNEL_VERSION() macro.
__u32hw_revisionHardware device revision in a driver-specific format.
__u32driver_versionMedia device driver version, formatted with the KERNEL_VERSION() macro. Together with the driver field this identifies a particular driver.
__u32reserved[31]Reserved for future extensions. Drivers and applications must set this array to zero.

The serial and bus_info fields can be used to distinguish between multiple instances of otherwise identical hardware. The serial number takes precedence when provided and can be assumed to be unique. If the serial number is an empty string, the bus_info field can be used instead. The bus_info field is guaranteed to be unique, but can vary across reboots or device unplug/replug.

Return Value

On success 0 is returned, on error -1 and the errno variable is set appropriately. The generic error codes are described at the Generic Error Codes chapter.