osfmk/man/device_get_status.html
Function - Return the current device status.
**#include< device/device.h>**** kern\_return\_t device\_get\_status****(mach\_port\_t**device, **dev\_flavor\_t** flavor, **dev\_status\_t** status, **mach\_msg\_type\_number\_t** \*status\_count**);**
device[in device send right] A device port to the device to be interrogated.
flavor[in scalar] The type of status information requested.
status[out array of natural-sized units] The returned device status.
status_count[pointer to in/out scalar] On input, the reserved size of status; on output, the size of the returned device status (in natural-sized units).
The device_get_status function returns status information pertaining to an open device. The possible values for flavor as well as the meaning of the returned status information is device dependent.
D_DEVICE_DOWN Device has been shut down
D_NO_SUCH_DEVICE No device with that name, or the device is not operational.
D_OUT_OF_BAND Out-of-band condition occurred on device (such as typing *L-C*O)
Functions: device_set_status.