libusb0_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 "libusb0_common.h"

static bool jtag_libusb_match(struct jtag_libusb_device *dev,
        const uint16_t vids[], const uint16_t pids[])
{
    for (unsigned i = 0; vids[i]; i++) {
        if (dev->descriptor.idVendor == vids[i] &&
            dev->descriptor.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(usb_dev_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 = usb_get_string_simple(device, str_index,
            desc_string, sizeof(desc_string)-1);
    if (retval < 0) {
        LOG_ERROR("usb_get_string_simple() 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 retval = -ENODEV;
    struct jtag_libusb_device_handle *libusb_handle;
    usb_init();

    usb_find_busses();
    usb_find_devices();

    struct usb_bus *busses = usb_get_busses();
    for (struct usb_bus *bus = busses; bus; bus = bus->next) {
        for (struct usb_device *dev = bus->devices;
                dev; dev = dev->next) {
            if (!jtag_libusb_match(dev, vids, pids))
                continue;

            libusb_handle = usb_open(dev);
            if (NULL == libusb_handle) {
                retval = -errno;
                continue;
            }

            /* Device must be open to use libusb_get_string_descriptor_ascii. */
            if (serial != NULL &&
                    !string_descriptor_equal(libusb_handle, dev->descriptor.iSerialNumber, serial)) {
                usb_close(libusb_handle);
                continue;
            }
            *out = libusb_handle;
            retval = 0;
            break;
        }
    }
    return retval;
}

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

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 = usb_control_msg(dev, requestType, request, wValue, wIndex,
                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)
{
    return usb_bulk_write(dev, ep, bytes, size, timeout);
}

int jtag_libusb_bulk_read(jtag_libusb_device_handle *dev, int ep, char *bytes,
        int size, int timeout)
{
    return usb_bulk_read(dev, ep, bytes, size, timeout);
}

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

    return usb_set_configuration(devh,
            udev->config[configuration].bConfigurationValue);
}

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);
    struct usb_interface *iface = udev->config->interface;
    struct usb_interface_descriptor *desc = iface->altsetting;

    *usb_read_ep = *usb_write_ep = 0;

    for (int i = 0; i < desc->bNumEndpoints; i++) {
        if ((bclass > 0 && desc->bInterfaceClass != bclass) ||
            (subclass > 0 && desc->bInterfaceSubClass != subclass) ||
            (protocol > 0 && desc->bInterfaceProtocol != protocol))
            continue;

        uint8_t epnum = desc->endpoint[i].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)desc->bInterfaceNumber);
            usb_claim_interface(devh, (int)desc->bInterfaceNumber);
            return ERROR_OK;
        }
    }

    return ERROR_FAIL;
}

int jtag_libusb_get_pid(struct jtag_libusb_device *dev, uint16_t *pid)
{
    if (!dev)
        return ERROR_FAIL;

    *pid = dev->descriptor.idProduct;
    return ERROR_OK;
}