osfmk/man/device_close.html
Function - De-establish a connection to a device.
**#include< device/device.h>**** kern\_return\_t device\_close****(mach\_port\_t**device**);**
device[in device send right] A device port to the device to be closed.
The device_close function destroys the associated device port. The open count for the named device is decremented. If this count reaches zero, the close operation of the device driver is invoked, closing the device.
device_close will destroy any mapped device windows obtained through this device port.
D_NO_SUCH_DEVICE No device with that name, or the device is not operational.
Functions: device_open.