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 ***************************************************************************/
38 #include <helper/system.h>
40 #include <helper/log.h>
41 #include <helper/replacements.h>
43 #include "cmsis_dap.h"
45 struct cmsis_dap_backend_data {
46 struct libusb_context *usb_ctx;
47 struct libusb_device_handle *dev_handle;
53 static int cmsis_dap_usb_interface = -1;
55 static void cmsis_dap_usb_close(struct cmsis_dap *dap);
56 static int cmsis_dap_usb_alloc(struct cmsis_dap *dap, unsigned int pkt_sz);
58 static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t pids[], char *serial)
61 struct libusb_context *ctx;
62 struct libusb_device **device_list;
64 err = libusb_init(&ctx);
66 LOG_ERROR("libusb initialization failed: %s", libusb_strerror(err));
70 int num_devices = libusb_get_device_list(ctx, &device_list);
71 if (num_devices < 0) {
72 LOG_ERROR("could not enumerate USB devices: %s", libusb_strerror(num_devices));
77 for (int i = 0; i < num_devices; i++) {
78 struct libusb_device *dev = device_list[i];
79 struct libusb_device_descriptor dev_desc;
81 err = libusb_get_device_descriptor(dev, &dev_desc);
83 LOG_ERROR("could not get device descriptor for device %d: %s", i, libusb_strerror(err));
89 bool id_match = false;
90 bool id_filter = vids[0] || pids[0];
91 for (int id = 0; vids[id] || pids[id]; id++) {
92 id_match = !vids[id] || dev_desc.idVendor == vids[id];
93 id_match &= !pids[id] || dev_desc.idProduct == pids[id];
99 if (id_filter && !id_match)
102 /* Don't continue if we asked for a serial number and the device doesn't have one */
103 if (dev_desc.iSerialNumber == 0 && serial && serial[0])
106 struct libusb_device_handle *dev_handle = NULL;
107 err = libusb_open(dev, &dev_handle);
109 /* It's to be expected that most USB devices can't be opened
110 * so only report an error if it was explicitly selected
113 LOG_ERROR("could not open device 0x%04x:0x%04x: %s",
114 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
116 LOG_DEBUG("could not open device 0x%04x:0x%04x: %s",
117 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
122 /* Match serial number */
124 bool serial_match = false;
125 char dev_serial[256] = {0};
126 if (dev_desc.iSerialNumber > 0) {
127 err = libusb_get_string_descriptor_ascii(
128 dev_handle, dev_desc.iSerialNumber,
129 (uint8_t *)dev_serial, sizeof(dev_serial));
132 const char *msg = "could not read serial number for device 0x%04x:0x%04x: %s";
134 LOG_WARNING(msg, dev_desc.idVendor, dev_desc.idProduct,
135 libusb_strerror(err));
137 LOG_DEBUG(msg, dev_desc.idVendor, dev_desc.idProduct,
138 libusb_strerror(err));
139 } else if (serial && strncmp(dev_serial, serial, sizeof(dev_serial)) == 0) {
144 if (serial && !serial_match) {
145 libusb_close(dev_handle);
149 /* Find the CMSIS-DAP string in product string */
151 bool cmsis_dap_in_product_str = false;
152 char product_string[256] = {0};
153 if (dev_desc.iProduct > 0) {
154 err = libusb_get_string_descriptor_ascii(
155 dev_handle, dev_desc.iProduct,
156 (uint8_t *)product_string, sizeof(product_string));
158 LOG_WARNING("could not read product string for device 0x%04x:0x%04x: %s",
159 dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
160 } else if (strstr(product_string, "CMSIS-DAP")) {
161 LOG_DEBUG("found product string of 0x%04x:0x%04x '%s'",
162 dev_desc.idVendor, dev_desc.idProduct, product_string);
163 cmsis_dap_in_product_str = true;
167 bool device_identified_reliably = cmsis_dap_in_product_str
168 || serial_match || id_match;
170 /* Find the CMSIS-DAP interface */
172 for (int config = 0; config < dev_desc.bNumConfigurations; config++) {
173 struct libusb_config_descriptor *config_desc;
174 err = libusb_get_config_descriptor(dev, config, &config_desc);
176 LOG_ERROR("could not get configuration descriptor %d for device 0x%04x:0x%04x: %s",
177 config, dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
181 LOG_DEBUG("enumerating interfaces of 0x%04x:0x%04x",
182 dev_desc.idVendor, dev_desc.idProduct);
183 int config_num = config_desc->bConfigurationValue;
184 const struct libusb_interface_descriptor *intf_desc_candidate = NULL;
185 const struct libusb_interface_descriptor *intf_desc_found = NULL;
187 for (int interface = 0; interface < config_desc->bNumInterfaces; interface++) {
188 const struct libusb_interface_descriptor *intf_desc = &config_desc->interface[interface].altsetting[0];
189 int interface_num = intf_desc->bInterfaceNumber;
191 /* Skip this interface if another one was requested explicitly */
192 if (cmsis_dap_usb_interface != -1 && cmsis_dap_usb_interface != interface_num)
195 /* CMSIS-DAP v2 spec says:
197 * CMSIS-DAP with default V2 configuration uses WinUSB and is therefore faster.
198 * Optionally support for streaming SWO trace is provided via an additional USB endpoint.
200 * The WinUSB configuration requires custom class support with the interface setting
201 * Class Code: 0xFF (Vendor specific)
203 * Protocol code: 0x00
205 * Depending on the configuration it uses the following USB endpoints which should be configured
206 * in the interface descriptor in this order:
207 * - Endpoint 1: Bulk Out ā used for commands received from host PC.
208 * - Endpoint 2: Bulk In ā used for responses send to host PC.
209 * - Endpoint 3: Bulk In (optional) ā used for streaming SWO trace (if enabled with SWO_STREAM).
212 /* Search for "CMSIS-DAP" in the interface string */
213 bool cmsis_dap_in_interface_str = false;
214 if (intf_desc->iInterface != 0) {
216 char interface_str[256] = {0};
218 err = libusb_get_string_descriptor_ascii(
219 dev_handle, intf_desc->iInterface,
220 (uint8_t *)interface_str, sizeof(interface_str));
222 LOG_DEBUG("could not read interface string %d for device 0x%04x:0x%04x: %s",
223 intf_desc->iInterface,
224 dev_desc.idVendor, dev_desc.idProduct,
225 libusb_strerror(err));
226 } else if (strstr(interface_str, "CMSIS-DAP")) {
227 cmsis_dap_in_interface_str = true;
228 LOG_DEBUG("found interface %d string '%s'",
229 interface_num, interface_str);
233 /* Bypass the following check if this interface was explicitly requested. */
234 if (cmsis_dap_usb_interface == -1) {
235 if (!cmsis_dap_in_product_str && !cmsis_dap_in_interface_str)
239 /* check endpoints */
240 if (intf_desc->bNumEndpoints < 2) {
241 LOG_DEBUG("skipping interface %d, has only %d endpoints",
242 interface_num, intf_desc->bNumEndpoints);
246 if ((intf_desc->endpoint[0].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
247 (intf_desc->endpoint[0].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_OUT) {
248 LOG_DEBUG("skipping interface %d, endpoint[0] is not bulk out",
253 if ((intf_desc->endpoint[1].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
254 (intf_desc->endpoint[1].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_IN) {
255 LOG_DEBUG("skipping interface %d, endpoint[1] is not bulk in",
260 /* We can rely on the interface is really CMSIS-DAP if
261 * - we've seen CMSIS-DAP in the interface string
262 * - config asked explicitly for an interface number
263 * - the device has only one interface
264 * The later two cases should be honored only if we know
265 * we are on the rigt device */
266 bool intf_identified_reliably = cmsis_dap_in_interface_str
267 || (device_identified_reliably &&
268 (cmsis_dap_usb_interface != -1
269 || config_desc->bNumInterfaces == 1));
271 if (intf_desc->bInterfaceClass != LIBUSB_CLASS_VENDOR_SPEC ||
272 intf_desc->bInterfaceSubClass != 0 || intf_desc->bInterfaceProtocol != 0) {
273 /* If the interface is reliably identified
274 * then we need not insist on setting USB class, subclass and protocol
275 * exactly as the specification requires.
276 * At least KitProg3 uses class 0 contrary to the specification */
277 if (intf_identified_reliably) {
278 LOG_WARNING("Using CMSIS-DAPv2 interface %d with wrong class %" PRId8
279 " subclass %" PRId8 " or protocol %" PRId8,
281 intf_desc->bInterfaceClass,
282 intf_desc->bInterfaceSubClass,
283 intf_desc->bInterfaceProtocol);
285 LOG_DEBUG("skipping interface %d, class %" PRId8
286 " subclass %" PRId8 " protocol %" PRId8,
288 intf_desc->bInterfaceClass,
289 intf_desc->bInterfaceSubClass,
290 intf_desc->bInterfaceProtocol);
296 if (intf_identified_reliably) {
297 /* That's the one! */
298 intf_desc_found = intf_desc;
302 if (!intf_desc_candidate && device_identified_reliably) {
303 /* This interface looks suitable for CMSIS-DAP. Store the pointer to it
304 * and keep searching for another one with CMSIS-DAP in interface string */
305 intf_desc_candidate = intf_desc;
309 if (!intf_desc_found) {
310 /* We were not able to identify reliably which interface is CMSIS-DAP.
311 * Let's use the first suitable if we found one */
312 intf_desc_found = intf_desc_candidate;
315 if (!intf_desc_found) {
316 libusb_free_config_descriptor(config_desc);
320 /* We've chosen an interface, connect to it */
321 int interface_num = intf_desc_found->bInterfaceNumber;
322 int packet_size = intf_desc_found->endpoint[0].wMaxPacketSize;
323 int ep_out = intf_desc_found->endpoint[0].bEndpointAddress;
324 int ep_in = intf_desc_found->endpoint[1].bEndpointAddress;
326 libusb_free_config_descriptor(config_desc);
327 libusb_free_device_list(device_list, true);
329 LOG_INFO("Using CMSIS-DAPv2 interface with VID:PID=0x%04x:0x%04x, serial=%s",
330 dev_desc.idVendor, dev_desc.idProduct, dev_serial);
333 err = libusb_get_configuration(dev_handle, ¤t_config);
335 LOG_ERROR("could not find current configuration: %s", libusb_strerror(err));
336 libusb_close(dev_handle);
341 if (config_num != current_config) {
342 err = libusb_set_configuration(dev_handle, config_num);
344 LOG_ERROR("could not set configuration: %s", libusb_strerror(err));
345 libusb_close(dev_handle);
351 err = libusb_claim_interface(dev_handle, interface_num);
353 LOG_WARNING("could not claim interface: %s", libusb_strerror(err));
355 dap->bdata = malloc(sizeof(struct cmsis_dap_backend_data));
356 if (dap->bdata == NULL) {
357 LOG_ERROR("unable to allocate memory");
358 libusb_release_interface(dev_handle, interface_num);
359 libusb_close(dev_handle);
364 dap->packet_size = packet_size;
365 dap->packet_buffer_size = packet_size;
366 dap->bdata->usb_ctx = ctx;
367 dap->bdata->dev_handle = dev_handle;
368 dap->bdata->ep_out = ep_out;
369 dap->bdata->ep_in = ep_in;
370 dap->bdata->interface = interface_num;
372 dap->packet_buffer = malloc(dap->packet_buffer_size);
373 if (dap->packet_buffer == NULL) {
374 LOG_ERROR("unable to allocate memory");
375 cmsis_dap_usb_close(dap);
379 dap->command = dap->packet_buffer;
380 dap->response = dap->packet_buffer;
385 libusb_close(dev_handle);
388 libusb_free_device_list(device_list, true);
394 static void cmsis_dap_usb_close(struct cmsis_dap *dap)
396 libusb_release_interface(dap->bdata->dev_handle, dap->bdata->interface);
397 libusb_close(dap->bdata->dev_handle);
398 libusb_exit(dap->bdata->usb_ctx);
401 free(dap->packet_buffer);
402 dap->packet_buffer = NULL;
405 static int cmsis_dap_usb_read(struct cmsis_dap *dap, int timeout_ms)
410 err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_in,
411 dap->packet_buffer, dap->packet_size, &transferred, timeout_ms);
413 if (err == LIBUSB_ERROR_TIMEOUT) {
414 return ERROR_TIMEOUT_REACHED;
416 LOG_ERROR("error reading data: %s", libusb_strerror(err));
421 memset(&dap->packet_buffer[transferred], 0, dap->packet_buffer_size - transferred);
426 static int cmsis_dap_usb_write(struct cmsis_dap *dap, int txlen, int timeout_ms)
431 /* skip the first byte that is only used by the HID backend */
432 err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_out,
433 dap->packet_buffer, txlen, &transferred, timeout_ms);
435 if (err == LIBUSB_ERROR_TIMEOUT) {
436 return ERROR_TIMEOUT_REACHED;
438 LOG_ERROR("error writing data: %s", libusb_strerror(err));
446 static int cmsis_dap_usb_alloc(struct cmsis_dap *dap, unsigned int pkt_sz)
448 uint8_t *buf = malloc(pkt_sz);
450 LOG_ERROR("unable to allocate CMSIS-DAP packet buffer");
454 dap->packet_buffer = buf;
455 dap->packet_size = pkt_sz;
456 dap->packet_buffer_size = pkt_sz;
458 dap->command = dap->packet_buffer;
459 dap->response = dap->packet_buffer;
464 COMMAND_HANDLER(cmsis_dap_handle_usb_interface_command)
467 cmsis_dap_usb_interface = strtoul(CMD_ARGV[0], NULL, 10);
469 LOG_ERROR("expected exactly one argument to cmsis_dap_usb_interface <interface_number>");
474 const struct command_registration cmsis_dap_usb_subcommand_handlers[] = {
477 .handler = &cmsis_dap_handle_usb_interface_command,
478 .mode = COMMAND_CONFIG,
479 .help = "set the USB interface number to use (for USB bulk backend only)",
480 .usage = "<interface_number>",
482 COMMAND_REGISTRATION_DONE
485 const struct cmsis_dap_backend cmsis_dap_usb_backend = {
487 .open = cmsis_dap_usb_open,
488 .close = cmsis_dap_usb_close,
489 .read = cmsis_dap_usb_read,
490 .write = cmsis_dap_usb_write,
491 .packet_buffer_alloc = cmsis_dap_usb_alloc,