summaryrefslogtreecommitdiffstats
path: root/libusb-1.0/libusb/sync.c
blob: d040d988a2602dd1bc492e0216f03660f33e55b7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
/*
 * 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_check(HANDLE_CTX(dev_handle), &completed);
		if (r < 0) {
			if (r == LIBUSB_ERROR_INTERRUPTED)
				continue;
			libusb_cancel_transfer(transfer);
			while (!completed)
				if (libusb_handle_events_check(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;
	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_check(HANDLE_CTX(dev_handle), &completed);
		if (r < 0) {
			if (r == LIBUSB_ERROR_INTERRUPTED)
				continue;
			libusb_cancel_transfer(transfer);
			while (!completed)
				if (libusb_handle_events_check(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);
}