fm.c

   1 /* fm.c - simple v4l compatible tuner for radio cards
   2
   3    Copyright (C) 1998  Russell Kroll <rkroll@exploits.org>
   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 2 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, write to the Free Software
  17    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <math.h>
  21 #include <stdio.h>
  22 #include <fcntl.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <getopt.h>
  26 #include <string.h>
  27 #include <asm/types.h>
  28 #include <sys/ioctl.h>
  29 #include <linux/videodev.h>
  30
  31 void help(char *prog)
  32 {
  33         printf ("usage: %s [-h] [-o] [-q] [-t <tuner>] <freq>|on|off [<volume>]\n", prog);
  34         printf ("\n");
  35         printf ("-h         - display this help\n");
  36         printf ("-o         - override frequency range limits in card\n");
  37         printf ("-q         - quiet mode\n");
  38         printf ("-t <tuner> - select tuner <tuner>\n");
  39         printf ("<tuner>    - tuner number - first one is 0, next one 1, etc\n");
  40         printf ("<freq>     - frequency in MHz (i.e. 94.3)\n");
  41         printf ("on         - turn radio on\n");
  42         printf ("off        - turn radio off (mute)\n");
  43         printf ("+          - increase volume\n");
  44         printf ("-          - decrease volume\n");
  45         printf ("<volume>   - intensity (0-65535)\n");
  46
  47         exit (1);
  48 }
  49
  50 void getconfig(int *defaultvol, int *increment)
  51 {
  52         FILE    *conf;
  53         char    buf[256], fn[256];
  54
  55         sprintf (fn, "%s/.fmrc", getenv("HOME"));
  56         conf = fopen (fn, "r");
  57
  58         if (!conf)
  59                 return;
  60
  61         while (fgets(buf, sizeof(buf), conf)) {
  62                 buf[strlen(buf)-1] = 0;
  63                 if (strncmp (buf, "VOL", 3) == 0)
  64                         sscanf (buf, "%*s %i", defaultvol);
  65                 if (strncmp (buf, "INCR", 3) == 0)
  66                         sscanf (buf, "%*s %i", increment);
  67         }
  68
  69         fclose (conf);
  70
  71         return;
  72 }
  73
  74 int main(int argc, char **argv)
  75 {
  76         int             fd, ret, tunevol, quiet=0, i, override = 0;
  77         int             defaultvol = 8192;      /* default volume = 12.5% */
  78         int             increment = 6554;       /* default change = 10% */
  79         double          fact;
  80         unsigned long   freq;
  81         struct          video_audio va;
  82         struct          video_tuner vt;
  83         char            *progname;
  84         extern  char    *optarg;
  85         extern  int     optind, opterr, optopt;
  86         int             tuner = 0;
  87
  88         if ((argc < 2) || (argc > 4)) {
  89                 printf ("usage: %s [-h] [-o] [-q] [-t <tuner>] <freq>|on|off [<volume>]\n", argv[0]);
  90                 exit (1);
  91         }
  92
  93         progname = argv[0];     /* used after getopt munges argv[] */
  94
  95         getconfig(&defaultvol, &increment);
  96
  97         while ((i = getopt(argc, argv, "+qhot:")) != EOF) {
  98                 switch (i) {
  99                         case 'q':
 100                                 quiet = 1;
 101                                 break;
 102                         case 'o':
 103                                 override = 1;
 104                                 break;
 105                         case 't':
 106                                 tuner = atoi(optarg);
 107                                 break;
 108                         case 'h':
 109                         default:
 110                                 help(argv[0]);
 111                                 break;
 112                 }
 113         }
 114
 115         argc -= optind;
 116         argv += optind;
 117
 118         if (argc == 2)
 119                 tunevol = atoi (argv[1]);
 120         else
 121                 tunevol = defaultvol;
 122
 123         if (argc == 0)          /* no frequency, on|off, or +|- given */
 124                 help (progname);
 125
 126         /* moved here so -h works without a device */
 127         fd = open ("/dev/radio0", O_RDONLY);
 128         if (fd == -1) {
 129                 perror ("Unable to open /dev/radio0");
 130                 exit (1);
 131         }
 132
 133         if (!strcmp("off", argv[0])) {          /* mute the radio */
 134                 va.audio = 0;
 135                 va.volume = 0;
 136                 va.flags = VIDEO_AUDIO_MUTE;
 137                 ret = ioctl (fd, VIDIOCSAUDIO, &va);
 138                 if (!quiet)
 139                         printf ("Radio muted\n");
 140                 exit (0);
 141         }
 142
 143         if (!strcmp("on", argv[0])) {           /* turn radio on */
 144                 va.audio = 0;
 145                 va.volume = tunevol;
 146                 va.flags = 0;
 147                 ret = ioctl (fd, VIDIOCSAUDIO, &va);
 148                 if (!quiet)
 149                         printf ("Radio on at %2.2f%% volume\n",
 150                                 (tunevol / 655.36));
 151                 exit (0);
 152         }
 153
 154         ret = ioctl (fd, VIDIOCGAUDIO, &va);
 155
 156         if (argv[0][0] == '+') {                /* volume up */
 157                 if ((va.volume + increment) > 65535)
 158                         va.volume = 65535;      /* catch overflows in __u16 */
 159                 else
 160                         va.volume += increment;
 161
 162                 if (!quiet)
 163                         printf ("Setting volume to %2.2f%%\n",
 164                                 (va.volume / 655.35));
 165                 ret = ioctl (fd, VIDIOCSAUDIO, &va);
 166                 exit (0);
 167         }
 168
 169         if (argv[0][0] == '-') {                /* volume down */
 170                 if ((va.volume - increment) < 0)
 171                         va.volume = 0;          /* catch negative numbers */
 172                 else
 173                         va.volume -= increment;
 174
 175                 if (!quiet)
 176                         printf ("Setting volume to %2.2f%%\n",
 177                                 (va.volume / 655.35));
 178                 ret = ioctl (fd, VIDIOCSAUDIO, &va);
 179                 exit (0);
 180         }
 181
 182         /* at this point, we are trying to tune to a frequency */
 183
 184         vt.tuner = tuner;
 185         ret = ioctl(fd, VIDIOCSTUNER, &vt);     /* set tuner # */
 186         if (ret < 0) {
 187                 perror ("set tuner");
 188                 exit (1);
 189         }
 190
 191         ret = ioctl(fd, VIDIOCGTUNER, &vt);     /* get frequency range */
 192
 193         if (ret == -1 || (vt.flags & VIDEO_TUNER_LOW) == 0)
 194           fact = 16.;
 195         else
 196           fact = 16000.;
 197         freq = ceil(atof(argv[0]) * fact);      /* rounding up matters */
 198
 199         if ((freq < vt.rangelow) || (freq > vt.rangehigh)) {
 200                 if (override == 0) {
 201                         printf ("Frequency %2.1f out of range (%2.1f - %2.1f MHz)\n",
 202                                 (freq / fact), (vt.rangelow / fact),
 203                                 (vt.rangehigh / fact));
 204                         exit (1);
 205                 }
 206         }
 207
 208         /* frequency sanity checked, proceed */
 209         ret = ioctl (fd, VIDIOCSFREQ, &freq);
 210         if (ret < 0) {
 211                 perror ("set freq");
 212                 exit (1);
 213         }
 214
 215         va.audio = 0;
 216         va.volume = tunevol;
 217         va.flags = 0;
 218         va.mode = VIDEO_SOUND_STEREO;
 219
 220         ret = ioctl (fd, VIDIOCSAUDIO, &va);    /* set the volume */
 221
 222         if (!quiet)
 223                 printf ("Radio tuned to %2.1f MHz at %2.2f%% volume\n",
 224                         (freq / fact), (tunevol / 655.35));
 225
 226         return (0);
 227 }