/***************************************************************************
* Copyright (C) 2018 by Mickaël Thomas *
* mickael9@gmail.com *
* *
* Copyright (C) 2016 by Maksym Hilliaka *
* oter@frozen-team.com *
* *
* Copyright (C) 2016 by Phillip Pearson *
* pp@myelin.co.nz *
* *
* Copyright (C) 2014 by Paul Fertser *
* fercerpav@gmail.com *
* *
* Copyright (C) 2013 by mike brown *
* mike@theshedworks.org.uk *
* *
* Copyright (C) 2013 by Spencer Oliver *
* spen@spen-soft.co.uk *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program 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 General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see . *
***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include
#include
#include "cmsis_dap.h"
struct cmsis_dap_backend_data {
libusb_context *usb_ctx;
libusb_device_handle *dev_handle;
unsigned int ep_out;
unsigned int ep_in;
int interface;
};
static int cmsis_dap_usb_interface = -1;
static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t pids[], char *serial)
{
int err;
libusb_context *ctx;
libusb_device **device_list;
err = libusb_init(&ctx);
if (err) {
LOG_ERROR("libusb initialization failed: %s", libusb_strerror(err));
return ERROR_FAIL;
}
int num_devices = libusb_get_device_list(ctx, &device_list);
if (num_devices < 0) {
LOG_ERROR("could not enumerate USB devices: %s", libusb_strerror(num_devices));
libusb_exit(ctx);
return ERROR_FAIL;
}
for (int i = 0; i < num_devices; i++) {
libusb_device *dev = device_list[i];
struct libusb_device_descriptor dev_desc;
err = libusb_get_device_descriptor(dev, &dev_desc);
if (err) {
LOG_ERROR("could not get device descriptor for device %d: %s", i, libusb_strerror(err));
continue;
}
/* Match VID/PID */
bool id_match = true; /* match if we don't enter the loop (no filter) */
for (int id = 0; vids[id] || pids[id]; id++) {
id_match = !vids[id] || dev_desc.idVendor == vids[id];
id_match &= !pids[id] || dev_desc.idProduct == pids[id];
if (id_match)
break;
}
if (!id_match)
continue;
/* Don't continue if we asked for a serial number and the device doesn't have one */
if (dev_desc.iSerialNumber == 0 && serial && serial[0])
continue;
libusb_device_handle *dev_handle = NULL;
err = libusb_open(dev, &dev_handle);
if (err) {
/* It's to be expected that most USB devices can't be opened
* so only report an error if it was explicitly selected
*/
if (vids[0] || pids[0]) {
LOG_ERROR("could not open device 0x%04x:0x%04x: %s",
dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
} else {
LOG_DEBUG("could not open device 0x%04x:0x%04x: %s",
dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
}
continue;
}
/* Match serial number */
bool serial_match = (serial == NULL);
char dev_serial[256] = {0};
if (dev_desc.iSerialNumber > 0) {
err = libusb_get_string_descriptor_ascii(
dev_handle, dev_desc.iSerialNumber,
(uint8_t *)dev_serial, sizeof(dev_serial));
if (err < 0) {
LOG_ERROR("could not read serial number for device 0x%04x:0x%04x: %s",
dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
} else if (serial && strncmp(dev_serial, serial, sizeof(dev_serial)) == 0) {
serial_match = true;
}
}
if (!serial_match) {
libusb_close(dev_handle);
continue;
}
/* Find the CMSIS-DAP string in product string */
bool cmsis_dap_found = false;
char product_string[256] = {0};
if (dev_desc.iProduct > 0) {
err = libusb_get_string_descriptor_ascii(
dev_handle, dev_desc.iProduct,
(uint8_t *)product_string, sizeof(product_string));
if (err < 0) {
LOG_ERROR("could not read product string for device 0x%04x:0x%04x: %s",
dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
} else if (strstr(product_string, "CMSIS-DAP")) {
LOG_DEBUG("CMSIS-DAP found in product string");
cmsis_dap_found = true;
}
}
/* Find the CMSIS-DAP interface */
for (int config = 0; config < dev_desc.bNumConfigurations; config++) {
struct libusb_config_descriptor *config_desc;
err = libusb_get_config_descriptor(dev, config, &config_desc);
if (err) {
LOG_ERROR("could not get configuration descriptor %d for device 0x%04x:0x%04x: %s",
config, dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
continue;
}
int config_num = config_desc->bConfigurationValue;
for (int interface = 0; interface < config_desc->bNumInterfaces; interface++) {
const struct libusb_interface_descriptor *intf_desc = &config_desc->interface[interface].altsetting[0];
int interface_num = intf_desc->bInterfaceNumber;
/* Skip this interface if another one was requested explicitly */
if (cmsis_dap_usb_interface != -1 && cmsis_dap_usb_interface != interface_num)
continue;
/* CMSIS-DAP v2 spec says:
*
* CMSIS-DAP with default V2 configuration uses WinUSB and is therefore faster.
* Optionally support for streaming SWO trace is provided via an additional USB endpoint.
*
* The WinUSB configuration requires custom class support with the interface setting
* Class Code: 0xFF (Vendor specific)
* Subclass: 0x00
* Protocol code: 0x00
*
* Depending on the configuration it uses the following USB endpoints which should be configured
* in the interface descriptor in this order:
* - Endpoint 1: Bulk Out – used for commands received from host PC.
* - Endpoint 2: Bulk In – used for responses send to host PC.
* - Endpoint 3: Bulk In (optional) – used for streaming SWO trace (if enabled with SWO_STREAM).
*/
if (intf_desc->bNumEndpoints < 2)
continue;
if ((intf_desc->endpoint[0].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
(intf_desc->endpoint[0].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_OUT)
continue;
if ((intf_desc->endpoint[1].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
(intf_desc->endpoint[1].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_IN)
continue;
/* Bypass the following checks if this interface was explicitly requested. */
if (cmsis_dap_usb_interface == -1) {
if (intf_desc->bInterfaceClass != LIBUSB_CLASS_VENDOR_SPEC ||
intf_desc->bInterfaceSubClass != 0 || intf_desc->bInterfaceProtocol != 0)
continue;
/* Search for "CMSIS-DAP" in the interface string */
if (cmsis_dap_usb_interface != -1 && !cmsis_dap_found) {
if (intf_desc->iInterface == 0)
continue;
char interface_str[256] = {0};
err = libusb_get_string_descriptor_ascii(
dev_handle, intf_desc->iInterface,
(uint8_t *)interface_str, sizeof(interface_str));
if (err < 0) {
LOG_ERROR("could not read interface string for device 0x%04x:0x%04x: %s",
dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
continue;
} else if (!strstr(interface_str, "CMSIS-DAP")) {
continue;
} else {
LOG_DEBUG("CMSIS-DAP found in interface string");
}
}
}
int packet_size = intf_desc->endpoint[0].wMaxPacketSize;
int ep_out = intf_desc->endpoint[0].bEndpointAddress;
int ep_in = intf_desc->endpoint[1].bEndpointAddress;
/* That's the one! */
libusb_free_config_descriptor(config_desc);
libusb_free_device_list(device_list, true);
LOG_INFO("Using CMSIS-DAPv2 interface with VID:PID=0x%04x:0x%04x, serial=%s",
dev_desc.idVendor, dev_desc.idProduct, dev_serial);
int current_config;
err = libusb_get_configuration(dev_handle, ¤t_config);
if (err) {
LOG_ERROR("could not find current configuration: %s", libusb_strerror(err));
libusb_close(dev_handle);
libusb_exit(ctx);
return ERROR_FAIL;
}
if (config_num != current_config) {
err = libusb_set_configuration(dev_handle, config_num);
if (err) {
LOG_ERROR("could not set configuration: %s", libusb_strerror(err));
libusb_close(dev_handle);
libusb_exit(ctx);
return ERROR_FAIL;
}
}
err = libusb_claim_interface(dev_handle, interface_num);
if (err)
LOG_WARNING("could not claim interface: %s", libusb_strerror(err));
dap->bdata = malloc(sizeof(struct cmsis_dap_backend_data));
if (dap->bdata == NULL) {
LOG_ERROR("unable to allocate memory");
libusb_release_interface(dev_handle, interface_num);
libusb_close(dev_handle);
libusb_exit(ctx);
return ERROR_FAIL;
}
dap->packet_size = packet_size + 1; /* "+ 1" for compatibility with the HID backend */
dap->bdata->usb_ctx = ctx;
dap->bdata->dev_handle = dev_handle;
dap->bdata->ep_out = ep_out;
dap->bdata->ep_in = ep_in;
dap->bdata->interface = interface_num;
return ERROR_OK;
}
libusb_free_config_descriptor(config_desc);
}
libusb_close(dev_handle);
}
libusb_free_device_list(device_list, true);
libusb_exit(ctx);
return ERROR_FAIL;
}
static void cmsis_dap_usb_close(struct cmsis_dap *dap)
{
libusb_release_interface(dap->bdata->dev_handle, dap->bdata->interface);
libusb_close(dap->bdata->dev_handle);
libusb_exit(dap->bdata->usb_ctx);
free(dap->bdata);
dap->bdata = NULL;
}
static int cmsis_dap_usb_read(struct cmsis_dap *dap, int timeout_ms)
{
int transferred = 0;
int err;
err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_in,
dap->packet_buffer, dap->packet_size, &transferred, timeout_ms);
if (err) {
if (err == LIBUSB_ERROR_TIMEOUT) {
return ERROR_TIMEOUT_REACHED;
} else {
LOG_ERROR("error reading data: %s", libusb_strerror(err));
return ERROR_FAIL;
}
}
memset(&dap->packet_buffer[transferred], 0, dap->packet_size - transferred);
return transferred;
}
static int cmsis_dap_usb_write(struct cmsis_dap *dap, int txlen, int timeout_ms)
{
int transferred = 0;
int err;
/* skip the first byte that is only used by the HID backend */
err = libusb_bulk_transfer(dap->bdata->dev_handle, dap->bdata->ep_out,
dap->packet_buffer + 1, txlen - 1, &transferred, timeout_ms);
if (err) {
if (err == LIBUSB_ERROR_TIMEOUT) {
return ERROR_TIMEOUT_REACHED;
} else {
LOG_ERROR("error writing data: %s", libusb_strerror(err));
return ERROR_FAIL;
}
}
return transferred;
}
COMMAND_HANDLER(cmsis_dap_handle_usb_interface_command)
{
if (CMD_ARGC == 1)
cmsis_dap_usb_interface = strtoul(CMD_ARGV[0], NULL, 10);
else
LOG_ERROR("expected exactly one argument to cmsis_dap_usb_interface ");
return ERROR_OK;
}
const struct command_registration cmsis_dap_usb_subcommand_handlers[] = {
{
.name = "interface",
.handler = &cmsis_dap_handle_usb_interface_command,
.mode = COMMAND_CONFIG,
.help = "set the USB interface number to use (for USB bulk backend only)",
.usage = "",
},
COMMAND_REGISTRATION_DONE
};
const struct cmsis_dap_backend cmsis_dap_usb_backend = {
.name = "usb_bulk",
.open = cmsis_dap_usb_open,
.close = cmsis_dap_usb_close,
.read = cmsis_dap_usb_read,
.write = cmsis_dap_usb_write,
};