usb_get_status — issues a GET_STATUS call
int usb_get_status (
struct usb_device * dev, int type, int target, void * data)
;
dev
the device whose status is being checked
type
USB_RECIP_*; for device, interface, or endpoint
target
zero (for device), else interface or endpoint number
data
pointer to two bytes of bitmap data
Returns device, interface, or endpoint status. Normally only of interest to see if the device is self powered, or has enabled the remote wakeup facility; or whether a bulk or interrupt endpoint is halted (“stalled”).
Bits in these status bitmaps are set using the SET_FEATURE request,
and cleared using the CLEAR_FEATURE request. The usb_clear_halt
function should be used to clear halt (“stall”) status.
This call is synchronous, and may not be used in an interrupt context.
Returns the number of bytes received on success, or else the status code
returned by the underlying usb_control_msg
call.