examples/am7xxx-modeswitch.c

   1 /* am7xxx-modeswitch - a simple usb-modeswitch for am7xxx devices
   2  *
   3  * Copyright (C) 2012-2014  Antonio Ospite <ao2@ao2.it>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <errno.h>
  22 #include <libusb.h>
  23
  24 #define AM7XXX_STORAGE_VID           0x1de1
  25 #define AM7XXX_STORAGE_PID           0x1101
  26 #define AM7XXX_STORAGE_CONFIGURATION 1
  27 #define AM7XXX_STORAGE_INTERFACE     0
  28 #define AM7XXX_STORAGE_OUT_EP        0x01
  29
  30 static unsigned char switch_command[] =
  31         "\x55\x53\x42\x43\x08\x70\x52\x89\x00\x00\x00\x00\x00\x00"
  32         "\x0c\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00";
  33
  34 int main(void)
  35 {
  36         int ret;
  37         libusb_device_handle *usb_device;
  38         int current_configuration;
  39         unsigned int len;
  40         int transferred;
  41
  42         ret = libusb_init(NULL);
  43         if (ret < 0) {
  44                 fprintf(stderr, "libusb_init failed: %s\n",
  45                         libusb_error_name(ret));
  46                 goto out;
  47         }
  48
  49         libusb_set_debug(NULL, LIBUSB_LOG_LEVEL_INFO);
  50
  51         usb_device = libusb_open_device_with_vid_pid(NULL,
  52                                                      AM7XXX_STORAGE_VID,
  53                                                      AM7XXX_STORAGE_PID);
  54         if (usb_device == NULL) {
  55                 fprintf(stderr, "libusb_open failed: %s\n", strerror(errno));
  56                 ret = -errno;
  57                 goto out;
  58         }
  59
  60         current_configuration = -1;
  61         ret = libusb_get_configuration(usb_device, &current_configuration);
  62         if (ret < 0) {
  63                 fprintf(stderr, "libusb_get_configuration failed: %s\n",
  64                         libusb_error_name(ret));
  65                 goto out_libusb_close;
  66         }
  67
  68         if (current_configuration != AM7XXX_STORAGE_CONFIGURATION) {
  69                 ret = libusb_set_configuration(usb_device,
  70                                                AM7XXX_STORAGE_CONFIGURATION);
  71                 if (ret < 0) {
  72                         fprintf(stderr, "libusb_set_configuration failed: %s\n",
  73                                 libusb_error_name(ret));
  74                         fprintf(stderr, "Cannot set configuration %hhu\n",
  75                                 AM7XXX_STORAGE_CONFIGURATION);
  76                         goto out_libusb_close;
  77                 }
  78         }
  79
  80         libusb_set_auto_detach_kernel_driver(usb_device, 1);
  81
  82         ret = libusb_claim_interface(usb_device, AM7XXX_STORAGE_INTERFACE);
  83         if (ret < 0) {
  84                 fprintf(stderr, "libusb_claim_interface failed: %s\n",
  85                         libusb_error_name(ret));
  86                 fprintf(stderr, "Cannot claim interface %hhu\n",
  87                         AM7XXX_STORAGE_INTERFACE);
  88                 goto out_libusb_close;
  89         }
  90
  91         /* Checking that the configuration has not changed, as suggested in
  92          * http://libusb.sourceforge.net/api-1.0/caveats.html
  93          */
  94         current_configuration = -1;
  95         ret = libusb_get_configuration(usb_device, &current_configuration);
  96         if (ret < 0) {
  97                 fprintf(stderr, "libusb_get_configuration after claim failed: %s\n",
  98                         libusb_error_name(ret));
  99                 goto out_libusb_release_interface;
 100         }
 101
 102         if (current_configuration != AM7XXX_STORAGE_CONFIGURATION) {
 103                 fprintf(stderr, "libusb configuration changed (expected: %hhu, current: %hhu\n",
 104                         AM7XXX_STORAGE_CONFIGURATION, current_configuration);
 105                 ret = -EINVAL;
 106                 goto out_libusb_release_interface;
 107         }
 108
 109         len = sizeof(switch_command);
 110
 111         transferred = 0;
 112         ret = libusb_bulk_transfer(usb_device, AM7XXX_STORAGE_OUT_EP,
 113                                    switch_command, len, &transferred, 0);
 114         if (ret != 0 || (unsigned int)transferred != len) {
 115                 fprintf(stderr, "ret: %d\ttransferred: %d (expected %u)\n",
 116                       ret, transferred, len);
 117                 goto out_libusb_release_interface;
 118         }
 119
 120         fprintf(stderr, "OK, command sent!\n");
 121
 122 out_libusb_release_interface:
 123         libusb_release_interface(usb_device, AM7XXX_STORAGE_INTERFACE);
 124 out_libusb_close:
 125         libusb_close(usb_device);
 126         usb_device = NULL;
 127 out:
 128         libusb_exit(NULL);
 129         return ret;
 130 }