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 void cmsis_dap_usb_close(struct cmsis_dap *dap);
54 static int cmsis_dap_usb_alloc(struct cmsis_dap *dap, unsigned int pkt_sz);
56 static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t pids[], char *serial)
60 libusb_device **device_list;
62 err = libusb_init(&ctx);
64 LOG_ERROR("libusb initialization failed: %s", libusb_strerror(err));
68 int num_devices = libusb_get_device_list(ctx, &device_list);
69 if (num_devices < 0) {
70 LOG_ERROR("could not enumerate USB devices: %s", libusb_strerror(num_devices));
75 for (int i = 0; i < num_devices; i++) {
76 libusb_device *dev = device_list[i];
77 struct libusb_device_descriptor dev_desc;
79 err = libusb_get_device_descriptor(dev, &dev_desc);
81 LOG_ERROR("could not get device descriptor for device %d: %s", i, libusb_strerror(err));
87 bool id_match = false;
88 bool id_filter = vids[0] || pids[0];
89 for (int id = 0; vids[id] || pids[id]; id++) {
90 id_match = !vids[id] || dev_desc.idVendor == vids[id];
91 id_match &= !pids[id] || dev_desc.idProduct == pids[id];
97 if (id_filter && !id_match)
100 /* Don't continue if we asked for a serial number and the device doesn't have one */
101 if (dev_desc.iSerialNumber == 0 && serial && serial[0])
104 libusb_device_handle *dev_handle = NULL;
105 err = libusb_open(dev, &dev_handle);
107 /* It's to be expected that most USB devices can't be opened
108 * so only report an error if it was explicitly selected
111 LOG_ERROR("could not open device 0x%04x:0x%04x: %s",
112 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
114 LOG_DEBUG("could not open device 0x%04x:0x%04x: %s",
115 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
120 /* Match serial number */
122 bool serial_match = false;
123 char dev_serial[256] = {0};
124 if (dev_desc.iSerialNumber > 0) {
125 err = libusb_get_string_descriptor_ascii(
126 dev_handle, dev_desc.iSerialNumber,
127 (uint8_t *)dev_serial, sizeof(dev_serial));
130 const char *msg = "could not read serial number for device 0x%04x:0x%04x: %s";
132 LOG_WARNING(msg, dev_desc.idVendor, dev_desc.idProduct,
133 libusb_strerror(err));
135 LOG_DEBUG(msg, dev_desc.idVendor, dev_desc.idProduct,
136 libusb_strerror(err));
137 } else if (serial && strncmp(dev_serial, serial, sizeof(dev_serial)) == 0) {
142 if (serial && !serial_match) {
143 libusb_close(dev_handle);
147 /* Find the CMSIS-DAP string in product string */
149 bool cmsis_dap_in_product_str = false;
150 char product_string[256] = {0};
151 if (dev_desc.iProduct > 0) {
152 err = libusb_get_string_descriptor_ascii(
153 dev_handle, dev_desc.iProduct,
154 (uint8_t *)product_string, sizeof(product_string));
156 LOG_WARNING("could not read product string for device 0x%04x:0x%04x: %s",
157 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
158 } else if (strstr(product_string, "CMSIS-DAP")) {
159 LOG_DEBUG("found product string of 0x%04x:0x%04x '%s'",
160 dev_desc.idVendor, dev_desc.idProduct, product_string);
161 cmsis_dap_in_product_str = true;
165 bool device_identified_reliably = cmsis_dap_in_product_str
166 || serial_match || id_match;
168 /* Find the CMSIS-DAP interface */
170 for (int config = 0; config < dev_desc.bNumConfigurations; config++) {
171 struct libusb_config_descriptor *config_desc;
172 err = libusb_get_config_descriptor(dev, config, &config_desc);
174 LOG_ERROR("could not get configuration descriptor %d for device 0x%04x:0x%04x: %s",
175 config, dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
179 LOG_DEBUG("enumerating interfaces of 0x%04x:0x%04x",
180 dev_desc.idVendor, dev_desc.idProduct);
181 int config_num = config_desc->bConfigurationValue;
182 const struct libusb_interface_descriptor *intf_desc_candidate = NULL;
183 const struct libusb_interface_descriptor *intf_desc_found = NULL;
185 for (int interface = 0; interface < config_desc->bNumInterfaces; interface++) {
186 const struct libusb_interface_descriptor *intf_desc = &config_desc->interface[interface].altsetting[0];
187 int interface_num = intf_desc->bInterfaceNumber;
189 /* Skip this interface if another one was requested explicitly */
190 if (cmsis_dap_usb_interface != -1 && cmsis_dap_usb_interface != interface_num)
193 /* CMSIS-DAP v2 spec says:
195 * CMSIS-DAP with default V2 configuration uses WinUSB and is therefore faster.
196 * Optionally support for streaming SWO trace is provided via an additional USB endpoint.
198 * The WinUSB configuration requires custom class support with the interface setting
199 * Class Code: 0xFF (Vendor specific)
201 * Protocol code: 0x00
203 * Depending on the configuration it uses the following USB endpoints which should be configured
204 * in the interface descriptor in this order:
205 * - Endpoint 1: Bulk Out ā used for commands received from host PC.
206 * - Endpoint 2: Bulk In ā used for responses send to host PC.
207 * - Endpoint 3: Bulk In (optional) ā used for streaming SWO trace (if enabled with SWO_STREAM).
210 /* Search for "CMSIS-DAP" in the interface string */
211 bool cmsis_dap_in_interface_str = false;
212 if (intf_desc->iInterface != 0) {
214 char interface_str[256] = {0};
216 err = libusb_get_string_descriptor_ascii(
217 dev_handle, intf_desc->iInterface,
218 (uint8_t *)interface_str, sizeof(interface_str));
220 LOG_DEBUG("could not read interface string %d for device 0x%04x:0x%04x: %s",
221 intf_desc->iInterface,
222 dev_desc.idVendor, dev_desc.idProduct,
223 libusb_strerror(err));
224 } else if (strstr(interface_str, "CMSIS-DAP")) {
225 cmsis_dap_in_interface_str = true;
226 LOG_DEBUG("found interface %d string '%s'",
227 interface_num, interface_str);
231 /* Bypass the following check if this interface was explicitly requested. */
232 if (cmsis_dap_usb_interface == -1) {
233 if (!cmsis_dap_in_product_str && !cmsis_dap_in_interface_str)
237 /* check endpoints */
238 if (intf_desc->bNumEndpoints < 2) {
239 LOG_DEBUG("skipping interface %d, has only %d endpoints",
240 interface_num, intf_desc->bNumEndpoints);
244 if ((intf_desc->endpoint[0].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
245 (intf_desc->endpoint[0].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_OUT) {
246 LOG_DEBUG("skipping interface %d, endpoint[0] is not bulk out",
251 if ((intf_desc->endpoint[1].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
252 (intf_desc->endpoint[1].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_IN) {
253 LOG_DEBUG("skipping interface %d, endpoint[1] is not bulk in",
258 /* We can rely on the interface is really CMSIS-DAP if
259 * - we've seen CMSIS-DAP in the interface string
260 * - config asked explicitly for an interface number
261 * - the device has only one interface
262 * The later two cases should be honored only if we know
263 * we are on the rigt device */
264 bool intf_identified_reliably = cmsis_dap_in_interface_str
265 || (device_identified_reliably &&
266 (cmsis_dap_usb_interface != -1
267 || config_desc->bNumInterfaces == 1));
269 if (intf_desc->bInterfaceClass != LIBUSB_CLASS_VENDOR_SPEC ||
270 intf_desc->bInterfaceSubClass != 0 || intf_desc->bInterfaceProtocol != 0) {
271 /* If the interface is reliably identified
272 * then we need not insist on setting USB class, subclass and protocol
273 * exactly as the specification requires.
274 * At least KitProg3 uses class 0 contrary to the specification */
275 if (intf_identified_reliably) {
276 LOG_WARNING("Using CMSIS-DAPv2 interface %d with wrong class %" PRId8
277 " subclass %" PRId8 " or protocol %" PRId8,
279 intf_desc->bInterfaceClass,
280 intf_desc->bInterfaceSubClass,
281 intf_desc->bInterfaceProtocol);
283 LOG_DEBUG("skipping interface %d, class %" PRId8
284 " subclass %" PRId8 " protocol %" PRId8,
286 intf_desc->bInterfaceClass,
287 intf_desc->bInterfaceSubClass,
288 intf_desc->bInterfaceProtocol);
294 if (intf_identified_reliably) {
295 /* That's the one! */
296 intf_desc_found = intf_desc;
300 if (!intf_desc_candidate && device_identified_reliably) {
301 /* This interface looks suitable for CMSIS-DAP. Store the pointer to it
302 * and keep searching for another one with CMSIS-DAP in interface string */
303 intf_desc_candidate = intf_desc;
307 if (!intf_desc_found) {
308 /* We were not able to identify reliably which interface is CMSIS-DAP.
309 * Let's use the first suitable if we found one */
310 intf_desc_found = intf_desc_candidate;
313 if (!intf_desc_found) {
314 libusb_free_config_descriptor(config_desc);
318 /* We've chosen an interface, connect to it */
319 int interface_num = intf_desc_found->bInterfaceNumber;
320 int packet_size = intf_desc_found->endpoint[0].wMaxPacketSize;
321 int ep_out = intf_desc_found->endpoint[0].bEndpointAddress;
322 int ep_in = intf_desc_found->endpoint[1].bEndpointAddress;
324 libusb_free_config_descriptor(config_desc);
325 libusb_free_device_list(device_list, true);
327 LOG_INFO("Using CMSIS-DAPv2 interface with VID:PID=0x%04x:0x%04x, serial=%s",
328 dev_desc.idVendor, dev_desc.idProduct, dev_serial);
331 err = libusb_get_configuration(dev_handle, ¤t_config);
333 LOG_ERROR("could not find current configuration: %s", libusb_strerror(err));
334 libusb_close(dev_handle);
339 if (config_num != current_config) {
340 err = libusb_set_configuration(dev_handle, config_num);
342 LOG_ERROR("could not set configuration: %s", libusb_strerror(err));
343 libusb_close(dev_handle);
349 err = libusb_claim_interface(dev_handle, interface_num);
351 LOG_WARNING("could not claim interface: %s", libusb_strerror(err));
353 dap->bdata = malloc(sizeof(struct cmsis_dap_backend_data));
354 if (dap->bdata == NULL) {
355 LOG_ERROR("unable to allocate memory");
356 libusb_release_interface(dev_handle, interface_num);
357 libusb_close(dev_handle);
362 dap->packet_size = packet_size;
363 dap->packet_buffer_size = packet_size + REPORT_ID_SIZE;
364 dap->bdata->usb_ctx = ctx;
365 dap->bdata->dev_handle = dev_handle;
366 dap->bdata->ep_out = ep_out;
367 dap->bdata->ep_in = ep_in;
368 dap->bdata->interface = interface_num;
370 dap->packet_buffer = malloc(dap->packet_buffer_size);
371 if (dap->packet_buffer == NULL) {
372 LOG_ERROR("unable to allocate memory");
373 cmsis_dap_usb_close(dap);
380 libusb_close(dev_handle);
383 libusb_free_device_list(device_list, true);
389 static void cmsis_dap_usb_close(struct cmsis_dap *dap)
391 libusb_release_interface(dap->bdata->dev_handle, dap->bdata->interface);
392 libusb_close(dap->bdata->dev_handle);
393 libusb_exit(dap->bdata->usb_ctx);
396 free(dap->packet_buffer);
397 dap->packet_buffer = NULL;
400 static int cmsis_dap_usb_read(struct cmsis_dap *dap, int timeout_ms)
405 err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_in,
406 dap->packet_buffer, dap->packet_size, &transferred, timeout_ms);
408 if (err == LIBUSB_ERROR_TIMEOUT) {
409 return ERROR_TIMEOUT_REACHED;
411 LOG_ERROR("error reading data: %s", libusb_strerror(err));
416 memset(&dap->packet_buffer[transferred], 0, dap->packet_buffer_size - transferred);
421 static int cmsis_dap_usb_write(struct cmsis_dap *dap, int txlen, int timeout_ms)
426 /* skip the first byte that is only used by the HID backend */
427 err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_out,
428 dap->packet_buffer + REPORT_ID_SIZE, txlen - REPORT_ID_SIZE, &transferred, timeout_ms);
430 if (err == LIBUSB_ERROR_TIMEOUT) {
431 return ERROR_TIMEOUT_REACHED;
433 LOG_ERROR("error writing data: %s", libusb_strerror(err));
441 static int cmsis_dap_usb_alloc(struct cmsis_dap *dap, unsigned int pkt_sz)
443 unsigned int packet_buffer_size = pkt_sz + REPORT_ID_SIZE;
444 uint8_t *buf = malloc(packet_buffer_size);
446 LOG_ERROR("unable to allocate CMSIS-DAP packet buffer");
450 dap->packet_buffer = buf;
451 dap->packet_size = pkt_sz;
452 dap->packet_buffer_size = packet_buffer_size;
457 COMMAND_HANDLER(cmsis_dap_handle_usb_interface_command)
460 cmsis_dap_usb_interface = strtoul(CMD_ARGV[0], NULL, 10);
462 LOG_ERROR("expected exactly one argument to cmsis_dap_usb_interface <interface_number>");
467 const struct command_registration cmsis_dap_usb_subcommand_handlers[] = {
470 .handler = &cmsis_dap_handle_usb_interface_command,
471 .mode = COMMAND_CONFIG,
472 .help = "set the USB interface number to use (for USB bulk backend only)",
473 .usage = "<interface_number>",
475 COMMAND_REGISTRATION_DONE
478 const struct cmsis_dap_backend cmsis_dap_usb_backend = {
480 .open = cmsis_dap_usb_open,
481 .close = cmsis_dap_usb_close,
482 .read = cmsis_dap_usb_read,
483 .write = cmsis_dap_usb_write,
484 .packet_buffer_alloc = cmsis_dap_usb_alloc,