1 /***************************************************************************
2 * Copyright (C) 2018 by Mickaƫl Thomas *
5 * Copyright (C) 2016 by Maksym Hilliaka *
6 * oter@frozen-team.com *
8 * Copyright (C) 2016 by Phillip Pearson *
11 * Copyright (C) 2014 by Paul Fertser *
12 * fercerpav@gmail.com *
14 * Copyright (C) 2013 by mike brown *
15 * mike@theshedworks.org.uk *
17 * Copyright (C) 2013 by Spencer Oliver *
18 * spen@spen-soft.co.uk *
20 * This program is free software; you can redistribute it and/or modify *
21 * it under the terms of the GNU General Public License as published by *
22 * the Free Software Foundation; either version 2 of the License, or *
23 * (at your option) any later version. *
25 * This program is distributed in the hope that it will be useful, *
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
28 * GNU General Public License for more details. *
30 * You should have received a copy of the GNU General Public License *
31 * along with this program. If not, see <http://www.gnu.org/licenses/>. *
32 ***************************************************************************/
39 #include <helper/log.h>
41 #include "cmsis_dap.h"
43 struct cmsis_dap_backend_data {
44 libusb_context *usb_ctx;
45 libusb_device_handle *dev_handle;
51 static int cmsis_dap_usb_interface = -1;
53 static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t pids[], char *serial)
57 libusb_device **device_list;
59 err = libusb_init(&ctx);
61 LOG_ERROR("libusb initialization failed: %s", libusb_strerror(err));
65 int num_devices = libusb_get_device_list(ctx, &device_list);
66 if (num_devices < 0) {
67 LOG_ERROR("could not enumerate USB devices: %s", libusb_strerror(num_devices));
72 for (int i = 0; i < num_devices; i++) {
73 libusb_device *dev = device_list[i];
74 struct libusb_device_descriptor dev_desc;
76 err = libusb_get_device_descriptor(dev, &dev_desc);
78 LOG_ERROR("could not get device descriptor for device %d: %s", i, libusb_strerror(err));
84 bool id_match = false;
85 bool id_filter = vids[0] || pids[0];
86 for (int id = 0; vids[id] || pids[id]; id++) {
87 id_match = !vids[id] || dev_desc.idVendor == vids[id];
88 id_match &= !pids[id] || dev_desc.idProduct == pids[id];
94 if (id_filter && !id_match)
97 /* Don't continue if we asked for a serial number and the device doesn't have one */
98 if (dev_desc.iSerialNumber == 0 && serial && serial[0])
101 libusb_device_handle *dev_handle = NULL;
102 err = libusb_open(dev, &dev_handle);
104 /* It's to be expected that most USB devices can't be opened
105 * so only report an error if it was explicitly selected
108 LOG_ERROR("could not open device 0x%04x:0x%04x: %s",
109 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
111 LOG_DEBUG("could not open device 0x%04x:0x%04x: %s",
112 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
117 /* Match serial number */
119 bool serial_match = false;
120 char dev_serial[256] = {0};
121 if (dev_desc.iSerialNumber > 0) {
122 err = libusb_get_string_descriptor_ascii(
123 dev_handle, dev_desc.iSerialNumber,
124 (uint8_t *)dev_serial, sizeof(dev_serial));
127 const char *msg = "could not read serial number for device 0x%04x:0x%04x: %s";
129 LOG_WARNING(msg, dev_desc.idVendor, dev_desc.idProduct,
130 libusb_strerror(err));
132 LOG_DEBUG(msg, dev_desc.idVendor, dev_desc.idProduct,
133 libusb_strerror(err));
134 } else if (serial && strncmp(dev_serial, serial, sizeof(dev_serial)) == 0) {
139 if (serial && !serial_match) {
140 libusb_close(dev_handle);
144 /* Find the CMSIS-DAP string in product string */
146 bool cmsis_dap_in_product_str = false;
147 char product_string[256] = {0};
148 if (dev_desc.iProduct > 0) {
149 err = libusb_get_string_descriptor_ascii(
150 dev_handle, dev_desc.iProduct,
151 (uint8_t *)product_string, sizeof(product_string));
153 LOG_WARNING("could not read product string for device 0x%04x:0x%04x: %s",
154 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
155 } else if (strstr(product_string, "CMSIS-DAP")) {
156 LOG_DEBUG("found product string of 0x%04x:0x%04x '%s'",
157 dev_desc.idVendor, dev_desc.idProduct, product_string);
158 cmsis_dap_in_product_str = true;
162 bool device_identified_reliably = cmsis_dap_in_product_str
163 || serial_match || id_match;
165 /* Find the CMSIS-DAP interface */
167 for (int config = 0; config < dev_desc.bNumConfigurations; config++) {
168 struct libusb_config_descriptor *config_desc;
169 err = libusb_get_config_descriptor(dev, config, &config_desc);
171 LOG_ERROR("could not get configuration descriptor %d for device 0x%04x:0x%04x: %s",
172 config, dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
176 LOG_DEBUG("enumerating interfaces of 0x%04x:0x%04x",
177 dev_desc.idVendor, dev_desc.idProduct);
178 int config_num = config_desc->bConfigurationValue;
179 const struct libusb_interface_descriptor *intf_desc_candidate = NULL;
180 const struct libusb_interface_descriptor *intf_desc_found = NULL;
182 for (int interface = 0; interface < config_desc->bNumInterfaces; interface++) {
183 const struct libusb_interface_descriptor *intf_desc = &config_desc->interface[interface].altsetting[0];
184 int interface_num = intf_desc->bInterfaceNumber;
186 /* Skip this interface if another one was requested explicitly */
187 if (cmsis_dap_usb_interface != -1 && cmsis_dap_usb_interface != interface_num)
190 /* CMSIS-DAP v2 spec says:
192 * CMSIS-DAP with default V2 configuration uses WinUSB and is therefore faster.
193 * Optionally support for streaming SWO trace is provided via an additional USB endpoint.
195 * The WinUSB configuration requires custom class support with the interface setting
196 * Class Code: 0xFF (Vendor specific)
198 * Protocol code: 0x00
200 * Depending on the configuration it uses the following USB endpoints which should be configured
201 * in the interface descriptor in this order:
202 * - Endpoint 1: Bulk Out ā used for commands received from host PC.
203 * - Endpoint 2: Bulk In ā used for responses send to host PC.
204 * - Endpoint 3: Bulk In (optional) ā used for streaming SWO trace (if enabled with SWO_STREAM).
207 /* Search for "CMSIS-DAP" in the interface string */
208 bool cmsis_dap_in_interface_str = false;
209 if (intf_desc->iInterface != 0) {
211 char interface_str[256] = {0};
213 err = libusb_get_string_descriptor_ascii(
214 dev_handle, intf_desc->iInterface,
215 (uint8_t *)interface_str, sizeof(interface_str));
217 LOG_DEBUG("could not read interface string %d for device 0x%04x:0x%04x: %s",
218 intf_desc->iInterface,
219 dev_desc.idVendor, dev_desc.idProduct,
220 libusb_strerror(err));
221 } else if (strstr(interface_str, "CMSIS-DAP")) {
222 cmsis_dap_in_interface_str = true;
223 LOG_DEBUG("found interface %d string '%s'",
224 interface_num, interface_str);
228 /* Bypass the following check if this interface was explicitly requested. */
229 if (cmsis_dap_usb_interface == -1) {
230 if (!cmsis_dap_in_product_str && !cmsis_dap_in_interface_str)
234 /* check endpoints */
235 if (intf_desc->bNumEndpoints < 2) {
236 LOG_DEBUG("skipping interface %d, has only %d endpoints",
237 interface_num, intf_desc->bNumEndpoints);
241 if ((intf_desc->endpoint[0].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
242 (intf_desc->endpoint[0].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_OUT) {
243 LOG_DEBUG("skipping interface %d, endpoint[0] is not bulk out",
248 if ((intf_desc->endpoint[1].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
249 (intf_desc->endpoint[1].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_IN) {
250 LOG_DEBUG("skipping interface %d, endpoint[1] is not bulk in",
255 /* We can rely on the interface is really CMSIS-DAP if
256 * - we've seen CMSIS-DAP in the interface string
257 * - config asked explicitly for an interface number
258 * - the device has only one interface
259 * The later two cases should be honored only if we know
260 * we are on the rigt device */
261 bool intf_identified_reliably = cmsis_dap_in_interface_str
262 || (device_identified_reliably &&
263 (cmsis_dap_usb_interface != -1
264 || config_desc->bNumInterfaces == 1));
266 if (intf_desc->bInterfaceClass != LIBUSB_CLASS_VENDOR_SPEC ||
267 intf_desc->bInterfaceSubClass != 0 || intf_desc->bInterfaceProtocol != 0) {
268 /* If the interface is reliably identified
269 * then we need not insist on setting USB class, subclass and protocol
270 * exactly as the specification requires.
271 * At least KitProg3 uses class 0 contrary to the specification */
272 if (intf_identified_reliably) {
273 LOG_WARNING("Using CMSIS-DAPv2 interface %d with wrong class %" PRId8
274 " subclass %" PRId8 " or protocol %" PRId8,
276 intf_desc->bInterfaceClass,
277 intf_desc->bInterfaceSubClass,
278 intf_desc->bInterfaceProtocol);
280 LOG_DEBUG("skipping interface %d, class %" PRId8
281 " subclass %" PRId8 " protocol %" PRId8,
283 intf_desc->bInterfaceClass,
284 intf_desc->bInterfaceSubClass,
285 intf_desc->bInterfaceProtocol);
291 if (intf_identified_reliably) {
292 /* That's the one! */
293 intf_desc_found = intf_desc;
297 if (!intf_desc_candidate && device_identified_reliably) {
298 /* This interface looks suitable for CMSIS-DAP. Store the pointer to it
299 * and keep searching for another one with CMSIS-DAP in interface string */
300 intf_desc_candidate = intf_desc;
304 if (!intf_desc_found) {
305 /* We were not able to identify reliably which interface is CMSIS-DAP.
306 * Let's use the first suitable if we found one */
307 intf_desc_found = intf_desc_candidate;
310 if (!intf_desc_found) {
311 libusb_free_config_descriptor(config_desc);
315 /* We've chosen an interface, connect to it */
316 int interface_num = intf_desc_found->bInterfaceNumber;
317 int packet_size = intf_desc_found->endpoint[0].wMaxPacketSize;
318 int ep_out = intf_desc_found->endpoint[0].bEndpointAddress;
319 int ep_in = intf_desc_found->endpoint[1].bEndpointAddress;
321 libusb_free_config_descriptor(config_desc);
322 libusb_free_device_list(device_list, true);
324 LOG_INFO("Using CMSIS-DAPv2 interface with VID:PID=0x%04x:0x%04x, serial=%s",
325 dev_desc.idVendor, dev_desc.idProduct, dev_serial);
328 err = libusb_get_configuration(dev_handle, ¤t_config);
330 LOG_ERROR("could not find current configuration: %s", libusb_strerror(err));
331 libusb_close(dev_handle);
336 if (config_num != current_config) {
337 err = libusb_set_configuration(dev_handle, config_num);
339 LOG_ERROR("could not set configuration: %s", libusb_strerror(err));
340 libusb_close(dev_handle);
346 err = libusb_claim_interface(dev_handle, interface_num);
348 LOG_WARNING("could not claim interface: %s", libusb_strerror(err));
350 dap->bdata = malloc(sizeof(struct cmsis_dap_backend_data));
351 if (dap->bdata == NULL) {
352 LOG_ERROR("unable to allocate memory");
353 libusb_release_interface(dev_handle, interface_num);
354 libusb_close(dev_handle);
359 dap->packet_size = packet_size + 1; /* "+ 1" for compatibility with the HID backend */
360 dap->bdata->usb_ctx = ctx;
361 dap->bdata->dev_handle = dev_handle;
362 dap->bdata->ep_out = ep_out;
363 dap->bdata->ep_in = ep_in;
364 dap->bdata->interface = interface_num;
368 libusb_close(dev_handle);
371 libusb_free_device_list(device_list, true);
377 static void cmsis_dap_usb_close(struct cmsis_dap *dap)
379 libusb_release_interface(dap->bdata->dev_handle, dap->bdata->interface);
380 libusb_close(dap->bdata->dev_handle);
381 libusb_exit(dap->bdata->usb_ctx);
386 static int cmsis_dap_usb_read(struct cmsis_dap *dap, int timeout_ms)
391 err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_in,
392 dap->packet_buffer, dap->packet_size, &transferred, timeout_ms);
394 if (err == LIBUSB_ERROR_TIMEOUT) {
395 return ERROR_TIMEOUT_REACHED;
397 LOG_ERROR("error reading data: %s", libusb_strerror(err));
402 memset(&dap->packet_buffer[transferred], 0, dap->packet_size - transferred);
407 static int cmsis_dap_usb_write(struct cmsis_dap *dap, int txlen, int timeout_ms)
412 /* skip the first byte that is only used by the HID backend */
413 err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_out,
414 dap->packet_buffer + 1, txlen - 1, &transferred, timeout_ms);
416 if (err == LIBUSB_ERROR_TIMEOUT) {
417 return ERROR_TIMEOUT_REACHED;
419 LOG_ERROR("error writing data: %s", libusb_strerror(err));
427 COMMAND_HANDLER(cmsis_dap_handle_usb_interface_command)
430 cmsis_dap_usb_interface = strtoul(CMD_ARGV[0], NULL, 10);
432 LOG_ERROR("expected exactly one argument to cmsis_dap_usb_interface <interface_number>");
437 const struct command_registration cmsis_dap_usb_subcommand_handlers[] = {
440 .handler = &cmsis_dap_handle_usb_interface_command,
441 .mode = COMMAND_CONFIG,
442 .help = "set the USB interface number to use (for USB bulk backend only)",
443 .usage = "<interface_number>",
445 COMMAND_REGISTRATION_DONE
448 const struct cmsis_dap_backend cmsis_dap_usb_backend = {
450 .open = cmsis_dap_usb_open,
451 .close = cmsis_dap_usb_close,
452 .read = cmsis_dap_usb_read,
453 .write = cmsis_dap_usb_write,