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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 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 */
}
/* FIXME: does this support partial transfers? */
/** \ingroup syncio
* Perform a USB control transfer. The direction of the transfer is inferred
* from the bRequestType field of the setup packet.
*
* \param dev_handle a handle for the device to communicate with
* \param bRequestType 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 bRequestType)
* \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 no timeout, use
* value 0.
* \returns 0 on success
* \returns -ETIMEDOUT if the transfer timed out
* \returns other negative code on error
*/
API_EXPORTED int libusb_control_transfer(libusb_device_handle *dev_handle,
uint8_t bRequestType, 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();
unsigned char *buffer;
int completed = 0;
int r;
if (!transfer)
return -ENOMEM;
buffer = malloc(LIBUSB_CONTROL_SETUP_SIZE + wLength);
if (!buffer) {
libusb_free_transfer(transfer);
return -ENOMEM;
}
libusb_fill_control_setup(buffer, bRequestType, bRequest, wValue, wIndex,
wLength);
if ((bRequestType & 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);
r = libusb_submit_transfer(transfer);
if (r < 0) {
libusb_free_transfer(transfer);
return r;
}
while (!completed) {
r = libusb_poll();
if (r < 0) {
libusb_cancel_transfer_sync(transfer);
libusb_free_transfer(transfer);
return r;
}
}
if ((bRequestType & 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 = -ETIMEDOUT;
break;
default:
usbi_warn("unrecognised status code %d", transfer->status);
r = -1;
}
libusb_free_transfer(transfer);
return r;
}
static void 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 endpoint_type)
{
struct libusb_transfer *transfer = libusb_alloc_transfer();
int completed = 0;
int r;
if (!transfer)
return -ENOMEM;
libusb_fill_bulk_transfer(transfer, dev_handle, endpoint, buffer, length,
bulk_transfer_cb, &completed, timeout);
transfer->endpoint_type = endpoint_type;
r = libusb_submit_transfer(transfer);
if (r < 0) {
libusb_free_transfer(transfer);
return r;
}
while (!completed) {
r = libusb_poll();
if (r < 0) {
libusb_cancel_transfer_sync(transfer);
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 = -ETIMEDOUT;
break;
default:
usbi_warn("unrecognised status code %d", transfer->status);
r = -1;
}
libusb_free_transfer(transfer);
return r;
}
/* FIXME: document timeout handling vs URB splitting */
/** \ingroup syncio
* Perform a USB bulk transfer. The direction of the transfer is inferred from
* the direction bits of the endpoint address.
*
* \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 no timeout, use
* value 0.
*
* \returns 0 on success (and populates <tt>transferred</tt>)
* \returns -ETIMEDOUT if the transfer timed out
* \returns other negative code on error
*/
API_EXPORTED int 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_ENDPOINT_TYPE_BULK);
}
/* FIXME: do we need an interval param here? usbfs doesn't expose it? */
/** \ingroup syncio
* Perform a USB interrupt transfer. The direction of the transfer is inferred
* from the direction bits of the endpoint address.
*
* \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 no timeout, use
* value 0.
*
* \returns 0 on success (and populates <tt>transferred</tt>)
* \returns -ETIMEDOUT if the transfer timed out
* \returns other negative code on error
*/
API_EXPORTED int 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_ENDPOINT_TYPE_INTERRUPT);
}
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