libusb_helper.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2009 by Zachary T Welch <zw@superlucidity.net>          *
 *                                                                         *
 *   Copyright (C) 2011 by Mauro Gamba <maurillo71@gmail.com>              *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <string.h>
 
#include <helper/log.h>
#include <jtag/adapter.h>
#include "libusb_helper.h"
 
/*
 * comment from libusb:
 * As per the USB 3.0 specs, the current maximum limit for the depth is 7.
 */
#define MAX_USB_PORTS   7
 
static struct libusb_context *jtag_libusb_context; 
static struct libusb_device **devs; 
static int jtag_libusb_error(int err)
{
    switch (err) {
    case LIBUSB_SUCCESS:
        return ERROR_OK;
    case LIBUSB_ERROR_TIMEOUT:
        return ERROR_TIMEOUT_REACHED;
    case LIBUSB_ERROR_IO:
    case LIBUSB_ERROR_INVALID_PARAM:
    case LIBUSB_ERROR_ACCESS:
    case LIBUSB_ERROR_NO_DEVICE:
    case LIBUSB_ERROR_NOT_FOUND:
    case LIBUSB_ERROR_BUSY:
    case LIBUSB_ERROR_OVERFLOW:
    case LIBUSB_ERROR_PIPE:
    case LIBUSB_ERROR_INTERRUPTED:
    case LIBUSB_ERROR_NO_MEM:
    case LIBUSB_ERROR_NOT_SUPPORTED:
    case LIBUSB_ERROR_OTHER:
        return ERROR_FAIL;
    default:
        return ERROR_FAIL;
    }
}
 
static bool jtag_libusb_match_ids(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;
}
 
#ifdef HAVE_LIBUSB_GET_PORT_NUMBERS
static bool jtag_libusb_location_equal(struct libusb_device *device)
{
    uint8_t port_path[MAX_USB_PORTS];
    uint8_t dev_bus;
    int path_len;
 
    path_len = libusb_get_port_numbers(device, port_path, MAX_USB_PORTS);
    if (path_len == LIBUSB_ERROR_OVERFLOW) {
        LOG_WARNING("cannot determine path to usb device! (more than %i ports in path)\n",
            MAX_USB_PORTS);
        return false;
    }
    dev_bus = libusb_get_bus_number(device);
 
    return adapter_usb_location_equal(dev_bus, port_path, path_len);
}
#else /* HAVE_LIBUSB_GET_PORT_NUMBERS */
static bool jtag_libusb_location_equal(struct libusb_device *device)
{
    return true;
}
#endif /* HAVE_LIBUSB_GET_PORT_NUMBERS */
 
 
/* Returns true if the string descriptor indexed by str_index in device matches string */
static bool string_descriptor_equal(struct 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;
}
 
static bool jtag_libusb_match_serial(struct libusb_device_handle *device,
        struct libusb_device_descriptor *dev_desc, const char *serial,
        adapter_get_alternate_serial_fn adapter_get_alternate_serial)
{
    if (string_descriptor_equal(device, dev_desc->iSerialNumber, serial))
        return true;
 
    /* check the alternate serial helper */
    if (!adapter_get_alternate_serial)
        return false;
 
    /* get the alternate serial */
    char *alternate_serial = adapter_get_alternate_serial(device, dev_desc);
 
    /* check possible failures */
    if (!alternate_serial)
        return false;
 
    /* then compare and free the alternate serial */
    bool match = false;
    if (strcmp(serial, alternate_serial) == 0)
        match = true;
    else
        LOG_DEBUG("Device alternate serial number '%s' doesn't match requested serial '%s'",
                alternate_serial, serial);
 
    free(alternate_serial);
    return match;
}
 
int jtag_libusb_open(const uint16_t vids[], const uint16_t pids[],
        struct libusb_device_handle **out,
        adapter_get_alternate_serial_fn adapter_get_alternate_serial)
{
    int cnt, idx, err_code;
    int retval = ERROR_FAIL;
    bool serial_mismatch = false;
    struct libusb_device_handle *libusb_handle = NULL;
    const char *serial = adapter_get_required_serial();
 
    if (libusb_init(&jtag_libusb_context) < 0)
        return ERROR_FAIL;
 
    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_ids(&dev_desc, vids, pids))
            continue;
 
        if (adapter_usb_get_location() && !jtag_libusb_location_equal(devs[idx]))
            continue;
 
        err_code = libusb_open(devs[idx], &libusb_handle);
 
        if (err_code) {
            LOG_ERROR("libusb_open() failed with %s",
                  libusb_error_name(err_code));
            continue;
        }
 
        /* Device must be open to use libusb_get_string_descriptor_ascii. */
        if (serial &&
                !jtag_libusb_match_serial(libusb_handle, &dev_desc, serial, adapter_get_alternate_serial)) {
            serial_mismatch = true;
            libusb_close(libusb_handle);
            continue;
        }
 
        /* Success. */
        *out = libusb_handle;
        retval = ERROR_OK;
        serial_mismatch = false;
        break;
    }
    if (cnt >= 0)
        libusb_free_device_list(devs, 1);
 
    if (serial_mismatch)
        LOG_INFO("No device matches the serial string");
 
    if (retval != ERROR_OK)
        libusb_exit(jtag_libusb_context);
 
    return retval;
}
 
void jtag_libusb_close(struct libusb_device_handle *dev)
{
    /* Close device */
    libusb_close(dev);
 
    libusb_exit(jtag_libusb_context);
}
 
int jtag_libusb_control_transfer(struct libusb_device_handle *dev, uint8_t request_type,
        uint8_t request, uint16_t value, uint16_t index, char *bytes,
        uint16_t size, unsigned int timeout)
{
    int transferred = 0;
 
    transferred = libusb_control_transfer(dev, request_type, request, value, index,
                (unsigned char *)bytes, size, timeout);
 
    if (transferred < 0)
        transferred = 0;
 
    return transferred;
}
 
int jtag_libusb_bulk_write(struct libusb_device_handle *dev, int ep, char *bytes,
               int size, int timeout, int *transferred)
{
    int ret;
 
    *transferred = 0;
 
    ret = libusb_bulk_transfer(dev, ep, (unsigned char *)bytes, size,
                   transferred, timeout);
    if (ret != LIBUSB_SUCCESS) {
        LOG_ERROR("libusb_bulk_write error: %s", libusb_error_name(ret));
        return jtag_libusb_error(ret);
    }
 
    return ERROR_OK;
}
 
int jtag_libusb_bulk_read(struct libusb_device_handle *dev, int ep, char *bytes,
              int size, int timeout, int *transferred)
{
    int ret;
 
    *transferred = 0;
 
    ret = libusb_bulk_transfer(dev, ep, (unsigned char *)bytes, size,
                   transferred, timeout);
    if (ret != LIBUSB_SUCCESS) {
        LOG_ERROR("libusb_bulk_read error: %s", libusb_error_name(ret));
        return jtag_libusb_error(ret);
    }
 
    return ERROR_OK;
}
 
int jtag_libusb_set_configuration(struct libusb_device_handle *devh,
        int configuration)
{
    struct libusb_device *udev = libusb_get_device(devh);
    int retval = -99;
 
    struct libusb_config_descriptor *config = NULL;
    int current_config = -1;
 
    retval = libusb_get_configuration(devh, &current_config);
    if (retval != 0)
        return retval;
 
    retval = libusb_get_config_descriptor(udev, configuration, &config);
    if (retval != 0 || !config)
        return retval;
 
    /* 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)
        retval = libusb_set_configuration(devh, config->bConfigurationValue);
 
    libusb_free_config_descriptor(config);
 
    return retval;
}
 
int jtag_libusb_choose_interface(struct libusb_device_handle *devh,
        unsigned int *usb_read_ep,
        unsigned int *usb_write_ep,
        int bclass, int subclass, int protocol, int trans_type)
{
    struct libusb_device *udev = 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];
            if (trans_type > 0 && (epdesc->bmAttributes & 0x3) != trans_type)
                continue;
 
            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 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;
}
 
int jtag_libusb_handle_events_completed(int *completed)
{
    return libusb_handle_events_completed(jtag_libusb_context, completed);
}