utils/ucmb-tools/tools/ucmb.c

   1 /*
   2  *   Microcontroller Message Bus
   3  *   Userspace commandline utility
   4  *
   5  *   Copyright (c) 2009 Michael Buesch <mb@bu3sch.de>
   6  *
   7  *   This program is free software; you can redistribute it and/or
   8  *   modify it under the terms of the GNU General Public License
   9  *   as published by the Free Software Foundation; either version 2
  10  *   of the License, or (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  */
  17
  18 #include <stdlib.h>
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <unistd.h>
  22 #include <fcntl.h>
  23 #include <errno.h>
  24 #include <sys/ioctl.h>
  25 #include <linux/ioctl.h>
  26
  27
  28 #define UCMB_DEV        "/dev/ucmb"
  29
  30 #define __UCMB_IOCTL            ('U'|'C'|'M'|'B')
  31 #define UCMB_IOCTL_RESETUC      _IO(__UCMB_IOCTL, 0)
  32
  33
  34 static void usage(int argc, char **argv)
  35 {
  36         fprintf(stderr, "Usage: %s read|write|reset [" UCMB_DEV "]\n", argv[0]);
  37 }
  38
  39 int main(int argc, char **argv)
  40 {
  41         const char *command, *devpath = UCMB_DEV;
  42         int res, errcode = 0;
  43         int ucmb_fd;
  44         char *buf;
  45         size_t count, buflen;
  46         ssize_t nrbytes;
  47
  48         if (argc != 2 && argc != 3) {
  49                 usage(argc, argv);
  50                 return 1;
  51         }
  52         if (argc == 3)
  53                 devpath = argv[2];
  54         command = argv[1];
  55
  56         ucmb_fd = open(devpath, O_RDWR);
  57         if (ucmb_fd == -1) {
  58                 fprintf(stderr, "Failed to open %s\n", UCMB_DEV);
  59                 errcode = 1;
  60                 goto out;
  61         }
  62
  63         buflen = 4096;
  64         buf = malloc(buflen);
  65         if (!buf) {
  66                 fprintf(stderr, "Out of memory\n");
  67                 errcode = 1;
  68                 goto out_close;
  69         }
  70
  71         if (strcasecmp(command, "read") == 0) {
  72                 nrbytes = read(ucmb_fd, buf, buflen);
  73                 if (nrbytes < 0) {
  74                         fprintf(stderr, "Failed to read UCMB: %s (%d)\n",
  75                                 strerror(errno), errno);
  76                         errcode = 1;
  77                         goto out_free;
  78                 }
  79                 if (fwrite(buf, nrbytes, 1, stdout) != 1) {
  80                         fprintf(stderr, "Failed to write stdout\n");
  81                         errcode = 1;
  82                         goto out_free;
  83                 }
  84         } else if (strcasecmp(command, "write") == 0) {
  85                 count = fread(buf, 1, buflen, stdin);
  86                 if (!count) {
  87                         fprintf(stderr, "Failed to read stdin\n");
  88                         errcode = 1;
  89                         goto out_free;
  90                 }
  91                 nrbytes = write(ucmb_fd, buf, count);
  92                 if (nrbytes != count) {
  93                         fprintf(stderr, "Failed to write UCMB: %s (%d)\n",
  94                                 strerror(errno), errno);
  95                         errcode = 1;
  96                         goto out_free;
  97                 }
  98         } else if (strcasecmp(command, "reset") == 0) {
  99                 res = ioctl(ucmb_fd, UCMB_IOCTL_RESETUC);
 100                 if (res) {
 101                         fprintf(stderr, "RESET ioctl failed: %s (%d)\n",
 102                                 strerror(res < 0 ? -res : res), res);
 103                         errcode = 1;
 104                         goto out_free;
 105                 }
 106         } else {
 107                 usage(argc, argv);
 108                 errcode = 1;
 109                 goto out_free;
 110         }
 111
 112 out_free:
 113         free(buf);
 114 out_close:
 115         close(ucmb_fd);
 116 out:
 117         return errcode;
 118 }