libusb1_common.c

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/***************************************************************************
 *   Copyright (C) 2009 by Zachary T Welch <zw@superlucidity.net>          *
 *                                                                         *
 *   Copyright (C) 2011 by Mauro Gamba <maurillo71@gmail.com>              *
 *                                                                         *
 *   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 <http://www.gnu.org/licenses/>. *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "log.h"
#include "libusb1_common.h"

static struct libusb_context *jtag_libusb_context; 
static libusb_device **devs; 
static bool jtag_libusb_match(struct libusb_device_descriptor *dev_desc,
        const uint16_t vids[], const uint16_t pids[])
{
    for (unsigned i = 0; vids[i]; i++) {
        if (dev_desc->idVendor == vids[i] &&
            dev_desc->idProduct == pids[i]) {
            return true;
        }
    }
    return false;
}

/* Returns true if the string descriptor indexed by str_index in device matches string */
static bool string_descriptor_equal(libusb_device_handle *device, uint8_t str_index,
                                    const char *string)
{
    int retval;
    bool matched;
    char desc_string[256+1]; /* Max size of string descriptor */

    if (str_index == 0)
        return false;

    retval = libusb_get_string_descriptor_ascii(device, str_index,
            (unsigned char *)desc_string, sizeof(desc_string)-1);
    if (retval < 0) {
        LOG_ERROR("libusb_get_string_descriptor_ascii() failed with %d", retval);
        return false;
    }

    /* Null terminate descriptor string in case it needs to be logged. */
    desc_string[sizeof(desc_string)-1] = '\0';

    matched = strncmp(string, desc_string, sizeof(desc_string)) == 0;
    if (!matched)
        LOG_DEBUG("Device serial number '%s' doesn't match requested serial '%s'",
            desc_string, string);
    return matched;
}

int jtag_libusb_open(const uint16_t vids[], const uint16_t pids[],
        const char *serial,
        struct jtag_libusb_device_handle **out)
{
    int cnt, idx, errCode;
    int retval = -ENODEV;
    struct jtag_libusb_device_handle *libusb_handle = NULL;

    if (libusb_init(&jtag_libusb_context) < 0)
        return -ENODEV;

    cnt = libusb_get_device_list(jtag_libusb_context, &devs);

    for (idx = 0; idx < cnt; idx++) {
        struct libusb_device_descriptor dev_desc;

        if (libusb_get_device_descriptor(devs[idx], &dev_desc) != 0)
            continue;

        if (!jtag_libusb_match(&dev_desc, vids, pids))
            continue;

        errCode = libusb_open(devs[idx], &libusb_handle);

        if (errCode) {
            LOG_ERROR("libusb_open() failed with %s",
                  libusb_error_name(errCode));
            continue;
        }

        /* Device must be open to use libusb_get_string_descriptor_ascii. */
        if (serial != NULL &&
                !string_descriptor_equal(libusb_handle, dev_desc.iSerialNumber, serial)) {
            libusb_close(libusb_handle);
            continue;
        }

        /* Success. */
        *out = libusb_handle;
        retval = 0;
        break;
    }
    if (cnt >= 0)
        libusb_free_device_list(devs, 1);
    return retval;
}

void jtag_libusb_close(jtag_libusb_device_handle *dev)
{
    /* Close device */
    libusb_close(dev);

    libusb_exit(jtag_libusb_context);
}

int jtag_libusb_control_transfer(jtag_libusb_device_handle *dev, uint8_t requestType,
        uint8_t request, uint16_t wValue, uint16_t wIndex, char *bytes,
        uint16_t size, unsigned int timeout)
{
    int transferred = 0;

    transferred = libusb_control_transfer(dev, requestType, request, wValue, wIndex,
                (unsigned char *)bytes, size, timeout);

    if (transferred < 0)
        transferred = 0;

    return transferred;
}

int jtag_libusb_bulk_write(jtag_libusb_device_handle *dev, int ep, char *bytes,
        int size, int timeout)
{
    int transferred = 0;

    libusb_bulk_transfer(dev, ep, (unsigned char *)bytes, size,
                 &transferred, timeout);
    return transferred;
}

int jtag_libusb_bulk_read(jtag_libusb_device_handle *dev, int ep, char *bytes,
        int size, int timeout)
{
    int transferred = 0;

    libusb_bulk_transfer(dev, ep, (unsigned char *)bytes, size,
                 &transferred, timeout);
    return transferred;
}

int jtag_libusb_set_configuration(jtag_libusb_device_handle *devh,
        int configuration)
{
    struct jtag_libusb_device *udev = jtag_libusb_get_device(devh);
    int retCode = -99;

    struct libusb_config_descriptor *config = NULL;
    int current_config = -1;

    retCode = libusb_get_configuration(devh, &current_config);
    if (retCode != 0)
        return retCode;

    retCode = libusb_get_config_descriptor(udev, configuration, &config);
    if (retCode != 0 || config == NULL)
        return retCode;

    /* Only change the configuration if it is not already set to the
       same one. Otherwise this issues a lightweight reset and hangs
       LPC-Link2 with JLink firmware. */
    if (current_config != config->bConfigurationValue)
        retCode = libusb_set_configuration(devh, config->bConfigurationValue);

    libusb_free_config_descriptor(config);

    return retCode;
}

int jtag_libusb_choose_interface(struct jtag_libusb_device_handle *devh,
        unsigned int *usb_read_ep,
        unsigned int *usb_write_ep,
        int bclass, int subclass, int protocol)
{
    struct jtag_libusb_device *udev = jtag_libusb_get_device(devh);
    const struct libusb_interface *inter;
    const struct libusb_interface_descriptor *interdesc;
    const struct libusb_endpoint_descriptor *epdesc;
    struct libusb_config_descriptor *config;

    *usb_read_ep = *usb_write_ep = 0;

    libusb_get_config_descriptor(udev, 0, &config);
    for (int i = 0; i < (int)config->bNumInterfaces; i++) {
        inter = &config->interface[i];

        interdesc = &inter->altsetting[0];
        for (int k = 0;
             k < (int)interdesc->bNumEndpoints; k++) {
            if ((bclass > 0 && interdesc->bInterfaceClass != bclass) ||
                (subclass > 0 && interdesc->bInterfaceSubClass != subclass) ||
                (protocol > 0 && interdesc->bInterfaceProtocol != protocol))
                continue;

            epdesc = &interdesc->endpoint[k];

            uint8_t epnum = epdesc->bEndpointAddress;
            bool is_input = epnum & 0x80;
            LOG_DEBUG("usb ep %s %02x",
                  is_input ? "in" : "out", epnum);

            if (is_input)
                *usb_read_ep = epnum;
            else
                *usb_write_ep = epnum;

            if (*usb_read_ep && *usb_write_ep) {
                LOG_DEBUG("Claiming interface %d", (int)interdesc->bInterfaceNumber);
                libusb_claim_interface(devh, (int)interdesc->bInterfaceNumber);
                libusb_free_config_descriptor(config);
                return ERROR_OK;
            }
        }
    }
    libusb_free_config_descriptor(config);

    return ERROR_FAIL;
}

int jtag_libusb_get_pid(struct jtag_libusb_device *dev, uint16_t *pid)
{
    struct libusb_device_descriptor dev_desc;

    if (libusb_get_device_descriptor(dev, &dev_desc) == 0) {
        *pid = dev_desc.idProduct;

        return ERROR_OK;
    }

    return ERROR_FAIL;
}