aboutsummaryrefslogtreecommitdiff
path: root/lowlevel.c
blob: 25a6f860a0c84cb2d01129e9a758eeb82028b8e9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/**
 * NXT bootstrap interface; low-level USB functions.
 *
 * Copyright 2006 David Anderson <david.anderson@calixo.net>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#include <assert.h>
#include <libusb.h>
#include <stdlib.h>
#include <string.h>

#include "lowlevel.h"

const struct
{
  int vendor_id;
  int product_id;
  int interface;
} nxt_usb_ids[N_FIRMWARES] = {
  { 0x03EB, 0x6124, 1 }, /* SAM-BA */
  { 0x0694, 0x0002, 0 }, /* LEGO   */
  { 0x0694, 0xFF00, 0 }  /* NXTOS  */
};

struct nxt_t
{
  libusb_context *usb;
  libusb_device *dev;
  nxt_firmware firmware;
  int interface;
  libusb_device_handle *hdl;
};

nxt_error_t
nxt_init(nxt_t **nxt)
{
  int ret;
  nxt_t *lnxt;

  lnxt = calloc(1, sizeof(*lnxt));
  if (!lnxt)
    return NXT_ERROR_NO_MEM;

  ret = libusb_init(&lnxt->usb);
  if (ret < 0)
    {
      free(lnxt);
      return NXT_ERROR_USB(ret);
    }

  *nxt = lnxt;
  return NXT_OK;
}

nxt_error_t
nxt_find(nxt_t *nxt)
{
  libusb_device **list;

  assert(!nxt->dev);

  ssize_t cnt = libusb_get_device_list(nxt->usb, &list);
  if (cnt < 0)
    {
      return NXT_ERROR_USB(cnt);
    }
  for (ssize_t j = 0; j < cnt; j++)
    {
      libusb_device *dev = list[j];
      struct libusb_device_descriptor desc;
      int ret = libusb_get_device_descriptor(dev, &desc);
      if (ret == 0)
        {
          for (int i = 0; i < N_FIRMWARES; i++)
            {
              if (desc.idVendor == nxt_usb_ids[i].vendor_id &&
                  desc.idProduct == nxt_usb_ids[i].product_id)
                {
                  libusb_ref_device(dev);
                  libusb_free_device_list(list, 1);
                  nxt->dev = dev;
                  nxt->firmware = i;
                  nxt->interface = nxt_usb_ids[i].interface;
                  return NXT_OK;
                }
            }
        }
    }

  libusb_free_device_list(list, 1);
  return NXT_NOT_PRESENT;
}

nxt_error_t
nxt_open(nxt_t *nxt)
{
  int ret;
  libusb_device_handle *hdl;

  assert(nxt->dev);
  assert(!nxt->hdl);

  ret = libusb_open(nxt->dev, &hdl);
  if (ret < 0)
    return NXT_ERROR_USB(ret);

  // Try to detach driver, but ignore errors when not implemented, or kernel
  // driver not attached.
  ret = libusb_detach_kernel_driver(hdl, nxt->interface);
  if (ret < 0 && ret != LIBUSB_ERROR_NOT_SUPPORTED &&
      ret != LIBUSB_ERROR_NOT_FOUND)
    {
      libusb_close(hdl);
      return NXT_ERROR_USB(ret);
    }

  ret = libusb_set_configuration(hdl, 1);
  if (ret < 0 && ret != LIBUSB_ERROR_NOT_SUPPORTED)
    {
      libusb_close(hdl);
      return NXT_ERROR_USB(ret);
    }

  ret = libusb_claim_interface(hdl, nxt->interface);
  if (ret < 0)
    {
      libusb_close(hdl);
      return NXT_ERROR_USB(ret);
    }

  nxt->hdl = hdl;
  return NXT_OK;
}

void
nxt_close(nxt_t *nxt)
{
  if (nxt->hdl)
    {
      libusb_release_interface(nxt->hdl, nxt->interface);
      libusb_close(nxt->hdl);
    }
  if (nxt->dev)
    libusb_unref_device(nxt->dev);
  libusb_exit(nxt->usb);
  free(nxt);
}

int
nxt_is_firmware(nxt_t *nxt, nxt_firmware fw)
{
  return (nxt->firmware == fw);
}

static nxt_error_t
nxt_transfer_buf(nxt_t *nxt, uint8_t endpoint, uint8_t *buf, int len)
{
  int ret;
  int transfered;

  do
    {
      ret = libusb_bulk_transfer(nxt->hdl, endpoint, buf, len, &transfered, 0);
      if (ret < 0)
        return NXT_ERROR_USB(ret);
      buf += transfered;
      len -= transfered;
    }
  while (len);

  return NXT_OK;
}

nxt_error_t
nxt_send_buf(nxt_t *nxt, const uint8_t *buf, int len)
{
  return nxt_transfer_buf(nxt, 0x01, (uint8_t *)buf, len);
}

nxt_error_t
nxt_send_str(nxt_t *nxt, const char *str)
{
  return nxt_send_buf(nxt, (const uint8_t *)str, strlen(str));
}

nxt_error_t
nxt_recv_buf(nxt_t *nxt, uint8_t *buf, int len)
{
  return nxt_transfer_buf(nxt, 0x82, buf, len);
}