openusb_ctrl_xfer, openusb_intr_xfer, openusb_bulk_xfer, openusb_isoc_xferopenusb_ctrl_xfer, openusb_intr_xfer, openusb_bulk_xfer, openusb_isoc_xfer -- Issue synchronous Control, Interrupt, Bulk, Isochronous request int32_t openusb_ctrl_xfer(openusb_dev_handle_t dev, uint8_t ifc, uint8_t ept, openusb_ctrl_request_t *ctrl);
int32_t openusb_intr_xfer(openusb_dev_handle_t dev, uint8_t ifc, uint8_t ept, openusb_intr_request_t *intr);
int32_t openusb_bulk_xfer(openusb_dev_handle_t dev, uint8_t ifc, uint8_t ept, openusb_bulk_request_t *bulk);
int32_t openusb_isoc_xfer(openusb_dev_handle_t dev, uint8_t ifc, uint8_t ept, openusb_isoc_request_t *isoc);
dev - Device handle.
ifc - Interface number.
ept - Endpoint number.
ctrl - Control request set by application.
intr - Interrupt request set by application.
bulk - Bulk request set by application.
isoc - Isochronous request set by application.
openusb_ctrl_xfer() is used to do synchronous USB
CONTROL transfers. Application should allocate and fill a openusb_ctrl_request:
struct openusb_ctrl_request {
struct openusb_ctrl_setup {
uint8_t bmRequestType;
uint8_t bRequest;
uint16_t wValue;
uint16_t wIndex;
/* wLength set automatically based on length */
} setup;
uint8_t *payload;
uint32_t length; /* platform endian */
uint32_t timeout;
uint32_t flags;
openusb_request_result_t result;
struct openusb_ctrl_request *next;
}
|
openusb_intr_xfer() is used to do synchronous USB
INTERRUPT transfers. Application should allocate and fill a openusb_intr_request:
struct openusb_intr_request {
uint16_t interval; /* may not work on some OS */
uint8_t *payload;
uint32_t length;
uint32_t timeout;
uint32_t flags;
openusb_request_result_t result;
struct openusb_intr_request *next;
}
|
openusb_bulk_xfer() is used to do synchronous USB
BULK transfers. Application should allocate and fill a openusb_bulk_request:
struct openusb_bulk_request {
uint8_t *payload;
uint32_t length;
uint32_t timeout;
uint32_t flags;
openusb_request_result_t result;
struct openusb_bulk_request *next;
}
|
openusb_isoc_xfer() is used to do synchronous USB
ISOCHRONOUS transfers. Application should allocate and fill a openusb_isoc_request:
typedef struct openusb_isoc_pkts {
uint32_t num_packets;
struct openusb_isoc_packet {
uint8_t *payload;
uint32_t length;
} *packets;
} openusb_isoc_pkts_t;
struct openusb_isoc_request {
uint32_t start_frame;
uint32_t flags;
openusb_isoc_pkts_t pkts;
/* pointer to isoc result array */
openusb_request_result_t *isoc_results;
/* overall isoc transfer completion status */
int32_t isoc_status;
struct openusb_isoc_request *next;
}
|
For openusb_ctrl_xfer, openusb_intr_xfer and openusb_bulk_xfer, the request status
is returned in openusb_request_result. Application may get transfer status and
length of its last request. For openusb_isoc_xfer(), every packet in the isoc request
has a corresponding result, application can check individual packet status
from the isoc_results. Application must allocate enough
number of isoc_results for openusb to fill the status.
openusb_request_result_t has the following elements:
int32_t status;
uint32_t transferred_bytes;
|
openusb_ctrl_xfer, openusb_intr_xfer, openusb_bulk_xfer and openusb_isoc_xfer
() returns 0 on success.
Otherwise, a openusb error is returned. NOTE, when there's no error, it just means submission of this request
succeed. Even if these functions didn't return failure, the data transfer may still have error and such kind of failure
is reflected in in result of individual request.
OPENUSB_SUCCESS No errors.
OPENUSB_BADARG handle or elements in handle
is not valid.
OPENUSB_UNKNOWN_DEVICE Device handle dev is not valid
OPENUSB_PLATFORM_FAILURE Unspecified kernel/driver failure
OPENUSB_NO_RESOURCES Memory allocation failure
OPENUSB_IO_* USB host controller errors