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- /*
- * Synchronous I/O functions for libusb
- * Copyright (C) 2007-2008 Daniel Drake <dsd@gentoo.org>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
- #include <config.h>
- #include <errno.h>
- #include <stdint.h>
- #include <stdlib.h>
- #include <string.h>
- #include "libusbi.h"
- /**
- * @defgroup syncio Synchronous device I/O
- *
- * This page documents libusb's synchronous (blocking) API for USB device I/O.
- * This interface is easy to use but has some limitations. More advanced users
- * may wish to consider using the \ref asyncio "asynchronous I/O API" instead.
- */
- static void LIBUSB_CALL ctrl_transfer_cb(struct libusb_transfer *transfer)
- {
- int *completed = transfer->user_data;
- *completed = 1;
- usbi_dbg("actual_length=%d", transfer->actual_length);
- /* caller interprets result and frees transfer */
- }
- /** \ingroup syncio
- * Perform a USB control transfer.
- *
- * The direction of the transfer is inferred from the bmRequestType field of
- * the setup packet.
- *
- * The wValue, wIndex and wLength fields values should be given in host-endian
- * byte order.
- *
- * \param dev_handle a handle for the device to communicate with
- * \param bmRequestType the request type field for the setup packet
- * \param bRequest the request field for the setup packet
- * \param wValue the value field for the setup packet
- * \param wIndex the index field for the setup packet
- * \param data a suitably-sized data buffer for either input or output
- * (depending on direction bits within bmRequestType)
- * \param wLength the length field for the setup packet. The data buffer should
- * be at least this size.
- * \param timeout timeout (in millseconds) that this function should wait
- * before giving up due to no response being received. For an unlimited
- * timeout, use value 0.
- * \returns on success, the number of bytes actually transferred
- * \returns LIBUSB_ERROR_TIMEOUT if the transfer timed out
- * \returns LIBUSB_ERROR_PIPE if the control request was not supported by the
- * device
- * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
- * \returns another LIBUSB_ERROR code on other failures
- */
- int API_EXPORTED libusb_control_transfer(libusb_device_handle *dev_handle,
- uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
- unsigned char *data, uint16_t wLength, unsigned int timeout)
- {
- struct libusb_transfer *transfer = libusb_alloc_transfer(0);
- unsigned char *buffer;
- int completed = 0;
- int r;
- if (!transfer)
- return LIBUSB_ERROR_NO_MEM;
- buffer = malloc(LIBUSB_CONTROL_SETUP_SIZE + wLength);
- if (!buffer) {
- libusb_free_transfer(transfer);
- return LIBUSB_ERROR_NO_MEM;
- }
- libusb_fill_control_setup(buffer, bmRequestType, bRequest, wValue, wIndex,
- wLength);
- if ((bmRequestType & LIBUSB_ENDPOINT_DIR_MASK) == LIBUSB_ENDPOINT_OUT)
- memcpy(buffer + LIBUSB_CONTROL_SETUP_SIZE, data, wLength);
- libusb_fill_control_transfer(transfer, dev_handle, buffer,
- ctrl_transfer_cb, &completed, timeout);
- transfer->flags = LIBUSB_TRANSFER_FREE_BUFFER;
- r = libusb_submit_transfer(transfer);
- if (r < 0) {
- libusb_free_transfer(transfer);
- return r;
- }
- while (!completed) {
- r = libusb_handle_events_completed(HANDLE_CTX(dev_handle), &completed);
- if (r < 0) {
- if (r == LIBUSB_ERROR_INTERRUPTED)
- continue;
- libusb_cancel_transfer(transfer);
- while (!completed)
- if (libusb_handle_events_completed(HANDLE_CTX(dev_handle), &completed) < 0)
- break;
- libusb_free_transfer(transfer);
- return r;
- }
- }
- if ((bmRequestType & LIBUSB_ENDPOINT_DIR_MASK) == LIBUSB_ENDPOINT_IN)
- memcpy(data, libusb_control_transfer_get_data(transfer),
- transfer->actual_length);
- switch (transfer->status) {
- case LIBUSB_TRANSFER_COMPLETED:
- r = transfer->actual_length;
- break;
- case LIBUSB_TRANSFER_TIMED_OUT:
- r = LIBUSB_ERROR_TIMEOUT;
- break;
- case LIBUSB_TRANSFER_STALL:
- r = LIBUSB_ERROR_PIPE;
- break;
- case LIBUSB_TRANSFER_NO_DEVICE:
- r = LIBUSB_ERROR_NO_DEVICE;
- break;
- case LIBUSB_TRANSFER_OVERFLOW:
- r = LIBUSB_ERROR_OVERFLOW;
- break;
- case LIBUSB_TRANSFER_ERROR:
- case LIBUSB_TRANSFER_CANCELLED:
- r = LIBUSB_ERROR_IO;
- break;
- default:
- usbi_warn(HANDLE_CTX(dev_handle),
- "unrecognised status code %d", transfer->status);
- r = LIBUSB_ERROR_OTHER;
- }
- libusb_free_transfer(transfer);
- return r;
- }
- static void LIBUSB_CALL bulk_transfer_cb(struct libusb_transfer *transfer)
- {
- int *completed = transfer->user_data;
- *completed = 1;
- usbi_dbg("actual_length=%d", transfer->actual_length);
- /* caller interprets results and frees transfer */
- }
- static int do_sync_bulk_transfer(struct libusb_device_handle *dev_handle,
- unsigned char endpoint, unsigned char *buffer, int length,
- int *transferred, unsigned int timeout, unsigned char type)
- {
- struct libusb_transfer *transfer = libusb_alloc_transfer(0);
- int completed = 0;
- int r;
- if (!transfer)
- return LIBUSB_ERROR_NO_MEM;
- libusb_fill_bulk_transfer(transfer, dev_handle, endpoint, buffer, length,
- bulk_transfer_cb, &completed, timeout);
- transfer->type = type;
- r = libusb_submit_transfer(transfer);
- if (r < 0) {
- libusb_free_transfer(transfer);
- return r;
- }
- while (!completed) {
- r = libusb_handle_events_completed(HANDLE_CTX(dev_handle), &completed);
- if (r < 0) {
- if (r == LIBUSB_ERROR_INTERRUPTED)
- continue;
- libusb_cancel_transfer(transfer);
- while (!completed)
- if (libusb_handle_events_completed(HANDLE_CTX(dev_handle), &completed) < 0)
- break;
- libusb_free_transfer(transfer);
- return r;
- }
- }
- *transferred = transfer->actual_length;
- switch (transfer->status) {
- case LIBUSB_TRANSFER_COMPLETED:
- r = 0;
- break;
- case LIBUSB_TRANSFER_TIMED_OUT:
- r = LIBUSB_ERROR_TIMEOUT;
- break;
- case LIBUSB_TRANSFER_STALL:
- r = LIBUSB_ERROR_PIPE;
- break;
- case LIBUSB_TRANSFER_OVERFLOW:
- r = LIBUSB_ERROR_OVERFLOW;
- break;
- case LIBUSB_TRANSFER_NO_DEVICE:
- r = LIBUSB_ERROR_NO_DEVICE;
- break;
- case LIBUSB_TRANSFER_ERROR:
- case LIBUSB_TRANSFER_CANCELLED:
- r = LIBUSB_ERROR_IO;
- break;
- default:
- usbi_warn(HANDLE_CTX(dev_handle),
- "unrecognised status code %d", transfer->status);
- r = LIBUSB_ERROR_OTHER;
- }
- libusb_free_transfer(transfer);
- return r;
- }
- /** \ingroup syncio
- * Perform a USB bulk transfer. The direction of the transfer is inferred from
- * the direction bits of the endpoint address.
- *
- * For bulk reads, the <tt>length</tt> field indicates the maximum length of
- * data you are expecting to receive. If less data arrives than expected,
- * this function will return that data, so be sure to check the
- * <tt>transferred</tt> output parameter.
- *
- * You should also check the <tt>transferred</tt> parameter for bulk writes.
- * Not all of the data may have been written.
- *
- * Also check <tt>transferred</tt> when dealing with a timeout error code.
- * libusb may have to split your transfer into a number of chunks to satisfy
- * underlying O/S requirements, meaning that the timeout may expire after
- * the first few chunks have completed. libusb is careful not to lose any data
- * that may have been transferred; do not assume that timeout conditions
- * indicate a complete lack of I/O.
- *
- * \param dev_handle a handle for the device to communicate with
- * \param endpoint the address of a valid endpoint to communicate with
- * \param data a suitably-sized data buffer for either input or output
- * (depending on endpoint)
- * \param length for bulk writes, the number of bytes from data to be sent. for
- * bulk reads, the maximum number of bytes to receive into the data buffer.
- * \param transferred output location for the number of bytes actually
- * transferred.
- * \param timeout timeout (in millseconds) that this function should wait
- * before giving up due to no response being received. For an unlimited
- * timeout, use value 0.
- *
- * \returns 0 on success (and populates <tt>transferred</tt>)
- * \returns LIBUSB_ERROR_TIMEOUT if the transfer timed out (and populates
- * <tt>transferred</tt>)
- * \returns LIBUSB_ERROR_PIPE if the endpoint halted
- * \returns LIBUSB_ERROR_OVERFLOW if the device offered more data, see
- * \ref packetoverflow
- * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
- * \returns another LIBUSB_ERROR code on other failures
- */
- int API_EXPORTED libusb_bulk_transfer(struct libusb_device_handle *dev_handle,
- unsigned char endpoint, unsigned char *data, int length, int *transferred,
- unsigned int timeout)
- {
- return do_sync_bulk_transfer(dev_handle, endpoint, data, length,
- transferred, timeout, LIBUSB_TRANSFER_TYPE_BULK);
- }
- /** \ingroup syncio
- * Perform a USB interrupt transfer. The direction of the transfer is inferred
- * from the direction bits of the endpoint address.
- *
- * For interrupt reads, the <tt>length</tt> field indicates the maximum length
- * of data you are expecting to receive. If less data arrives than expected,
- * this function will return that data, so be sure to check the
- * <tt>transferred</tt> output parameter.
- *
- * You should also check the <tt>transferred</tt> parameter for interrupt
- * writes. Not all of the data may have been written.
- *
- * Also check <tt>transferred</tt> when dealing with a timeout error code.
- * libusb may have to split your transfer into a number of chunks to satisfy
- * underlying O/S requirements, meaning that the timeout may expire after
- * the first few chunks have completed. libusb is careful not to lose any data
- * that may have been transferred; do not assume that timeout conditions
- * indicate a complete lack of I/O.
- *
- * The default endpoint bInterval value is used as the polling interval.
- *
- * \param dev_handle a handle for the device to communicate with
- * \param endpoint the address of a valid endpoint to communicate with
- * \param data a suitably-sized data buffer for either input or output
- * (depending on endpoint)
- * \param length for bulk writes, the number of bytes from data to be sent. for
- * bulk reads, the maximum number of bytes to receive into the data buffer.
- * \param transferred output location for the number of bytes actually
- * transferred.
- * \param timeout timeout (in millseconds) that this function should wait
- * before giving up due to no response being received. For an unlimited
- * timeout, use value 0.
- *
- * \returns 0 on success (and populates <tt>transferred</tt>)
- * \returns LIBUSB_ERROR_TIMEOUT if the transfer timed out
- * \returns LIBUSB_ERROR_PIPE if the endpoint halted
- * \returns LIBUSB_ERROR_OVERFLOW if the device offered more data, see
- * \ref packetoverflow
- * \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
- * \returns another LIBUSB_ERROR code on other error
- */
- int API_EXPORTED libusb_interrupt_transfer(
- struct libusb_device_handle *dev_handle, unsigned char endpoint,
- unsigned char *data, int length, int *transferred, unsigned int timeout)
- {
- return do_sync_bulk_transfer(dev_handle, endpoint, data, length,
- transferred, timeout, LIBUSB_TRANSFER_TYPE_INTERRUPT);
- }
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