/* * 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; 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; 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); }