drivers/char/radio-gemtek.c

   1 /* GemTek radio card driver for Linux (C) 1998 Jonas Munsin <jmunsin@iki.fi>
   2  *
   3  * GemTek hasn't released any specs on the card, so the protocol had to
   4  * be reverse engineered with dosemu.
   5  *
   6  * Besides the protocol changes, this is mostly a copy of:
   7  *
   8  *    RadioTrack II driver for Linux radio support (C) 1998 Ben Pfaff
   9  *
  10  *    Based on RadioTrack I/RadioReveal (C) 1997 M. Kirkwood
  11  *    Coverted to new API by Alan Cox <Alan.Cox@linux.org>
  12  *    Various bugfixes and enhancements by Russell Kroll <rkroll@exploits.org>
  13  *
  14  * TODO: Allow for more than one of these foolish entities :-)
  15  *
  16  */
  17
  18 #include <linux/module.h>       /* Modules                      */
  19 #include <linux/init.h>         /* Initdata                     */
  20 #include <linux/ioport.h>       /* check_region, request_region */
  21 #include <linux/delay.h>        /* udelay                       */
  22 #include <asm/io.h>             /* outb, outb_p                 */
  23 #include <asm/uaccess.h>        /* copy to/from user            */
  24 #include <linux/videodev.h>     /* kernel radio structs         */
  25 #include <linux/config.h>       /* CONFIG_RADIO_GEMTEK_PORT     */
  26
  27 #ifndef CONFIG_RADIO_GEMTEK_PORT
  28 #define CONFIG_RADIO_GEMTEK_PORT -1
  29 #endif
  30
  31 static int io = CONFIG_RADIO_GEMTEK_PORT;
  32 static int users = 0;
  33
  34 struct gemtek_device
  35 {
  36         int port;
  37         unsigned long curfreq;
  38         int muted;
  39 };
  40
  41
  42 /* local things */
  43
  44 /* the correct way to mute the gemtek may be to write the last written
  45  * frequency || 0x10, but just writing 0x10 once seems to do it as well
  46  */
  47 static void gemtek_mute(struct gemtek_device *dev)
  48 {
  49         if(dev->muted)
  50                 return;
  51         outb(0x10, io);
  52         dev->muted = 1;
  53 }
  54
  55 static void gemtek_unmute(struct gemtek_device *dev)
  56 {
  57         if(dev->muted == 0)
  58                 return;
  59         outb(0x20, io);
  60         dev->muted = 0;
  61 }
  62
  63 static void zero(void)
  64 {
  65         outb_p(0x04, io);
  66         udelay(5);
  67         outb_p(0x05, io);
  68         udelay(5);
  69 }
  70
  71 static void one(void)
  72 {
  73         outb_p(0x06, io);
  74         udelay(5);
  75         outb_p(0x07, io);
  76         udelay(5);
  77 }
  78
  79 static int gemtek_setfreq(struct gemtek_device *dev, unsigned long freq)
  80 {
  81         int i;
  82
  83 /*        freq = 78.25*((float)freq/16000.0 + 10.52); */
  84
  85         freq /= 16;
  86         freq += 10520;
  87         freq *= 7825;
  88         freq /= 100000;
  89
  90         /* 2 start bits */
  91         outb_p(0x03, io);
  92         udelay(5);
  93         outb_p(0x07, io);
  94         udelay(5);
  95
  96         /* 28 frequency bits (lsb first) */
  97         for (i = 0; i < 14; i++)
  98                 if (freq & (1 << i))
  99                         one();
 100                 else
 101                         zero();
 102         /* 36 unknown bits */
 103         for (i = 0; i < 11; i++)
 104                 zero();
 105         one();
 106         for (i = 0; i < 4; i++)
 107                 zero();
 108         one();
 109         zero();
 110
 111         /* 2 end bits */
 112         outb_p(0x03, io);
 113         udelay(5);
 114         outb_p(0x07, io);
 115         udelay(5);
 116
 117         return 0;
 118 }
 119
 120 int gemtek_getsigstr(struct gemtek_device *dev)
 121 {
 122         inb(io);
 123         udelay(5);
 124         if (inb(io) & 8)                /* bit set = no signal present */
 125                 return 0;
 126         return 1;               /* signal present */
 127 }
 128
 129 static int gemtek_ioctl(struct video_device *dev, unsigned int cmd, void *arg)
 130 {
 131         struct gemtek_device *rt=dev->priv;
 132
 133         switch(cmd)
 134         {
 135                 case VIDIOCGCAP:
 136                 {
 137                         struct video_capability v;
 138                         v.type=VID_TYPE_TUNER;
 139                         v.channels=1;
 140                         v.audios=1;
 141                         /* No we don't do pictures */
 142                         v.maxwidth=0;
 143                         v.maxheight=0;
 144                         v.minwidth=0;
 145                         v.minheight=0;
 146                         strcpy(v.name, "GemTek");
 147                         if(copy_to_user(arg,&v,sizeof(v)))
 148                                 return -EFAULT;
 149                         return 0;
 150                 }
 151                 case VIDIOCGTUNER:
 152                 {
 153                         struct video_tuner v;
 154                         if(copy_from_user(&v, arg,sizeof(v))!=0)
 155                                 return -EFAULT;
 156                         if(v.tuner)     /* Only 1 tuner */
 157                                 return -EINVAL;
 158                         v.rangelow=87*16000;
 159                         v.rangehigh=108*16000;
 160                         v.flags=VIDEO_TUNER_LOW;
 161                         v.mode=VIDEO_MODE_AUTO;
 162                         v.signal=0xFFFF*gemtek_getsigstr(rt);
 163                         strcpy(v.name, "FM");
 164                         if(copy_to_user(arg,&v, sizeof(v)))
 165                                 return -EFAULT;
 166                         return 0;
 167                 }
 168                 case VIDIOCSTUNER:
 169                 {
 170                         struct video_tuner v;
 171                         if(copy_from_user(&v, arg, sizeof(v)))
 172                                 return -EFAULT;
 173                         if(v.tuner!=0)
 174                                 return -EINVAL;
 175                         /* Only 1 tuner so no setting needed ! */
 176                         return 0;
 177                 }
 178                 case VIDIOCGFREQ:
 179                         if(copy_to_user(arg, &rt->curfreq, sizeof(rt->curfreq)))
 180                                 return -EFAULT;
 181                         return 0;
 182                 case VIDIOCSFREQ:
 183                         if(copy_from_user(&rt->curfreq, arg,sizeof(rt->curfreq)))
 184                                 return -EFAULT;
 185                 /* needs to be called twice in order for getsigstr to work */
 186                         gemtek_setfreq(rt, rt->curfreq);
 187                         gemtek_setfreq(rt, rt->curfreq);
 188                         return 0;
 189                 case VIDIOCGAUDIO:
 190                 {
 191                         struct video_audio v;
 192                         memset(&v,0, sizeof(v));
 193                         v.flags|=VIDEO_AUDIO_MUTABLE;
 194                         v.volume=1;
 195                         v.step=65535;
 196                         strcpy(v.name, "Radio");
 197                         if(copy_to_user(arg,&v, sizeof(v)))
 198                                 return -EFAULT;
 199                         return 0;
 200                 }
 201                 case VIDIOCSAUDIO:
 202                 {
 203                         struct video_audio v;
 204                         if(copy_from_user(&v, arg, sizeof(v)))
 205                                 return -EFAULT;
 206                         if(v.audio)
 207                                 return -EINVAL;
 208
 209                         if(v.flags&VIDEO_AUDIO_MUTE)
 210                                 gemtek_mute(rt);
 211                         else
 212                                 gemtek_unmute(rt);
 213
 214                         return 0;
 215                 }
 216                 default:
 217                         return -ENOIOCTLCMD;
 218         }
 219 }
 220
 221 static int gemtek_open(struct video_device *dev, int flags)
 222 {
 223         if(users)
 224                 return -EBUSY;
 225         users++;
 226         MOD_INC_USE_COUNT;
 227         return 0;
 228 }
 229
 230 static void gemtek_close(struct video_device *dev)
 231 {
 232         users--;
 233         MOD_DEC_USE_COUNT;
 234 }
 235
 236 static struct gemtek_device gemtek_unit;
 237
 238 static struct video_device gemtek_radio=
 239 {
 240         "GemTek radio",
 241         VID_TYPE_TUNER,
 242         VID_HARDWARE_GEMTEK,
 243         gemtek_open,
 244         gemtek_close,
 245         NULL,   /* Can't read  (no capture ability) */
 246         NULL,   /* Can't write */
 247         NULL,   /* Can't poll */
 248         gemtek_ioctl,
 249         NULL,
 250         NULL
 251 };
 252
 253 __initfunc(int gemtek_init(struct video_init *v))
 254 {
 255         if (check_region(io, 4))
 256         {
 257                 printk(KERN_ERR "gemtek: port 0x%x already in use\n", io);
 258                 return -EBUSY;
 259         }
 260
 261         gemtek_radio.priv=&gemtek_unit;
 262
 263         if(video_register_device(&gemtek_radio, VFL_TYPE_RADIO)==-1)
 264                 return -EINVAL;
 265
 266         request_region(io, 4, "gemtek");
 267         printk(KERN_INFO "GemTek Radio Card driver.\n");
 268
 269         /* mute card - prevents noisy bootups */
 270         outb(0x10, io);
 271         udelay(5);
 272         gemtek_unit.muted = 1;
 273
 274         /* this is _maybe_ unnecessary */
 275         outb(0x01, io);
 276
 277         return 0;
 278 }
 279
 280 #ifdef MODULE
 281
 282 MODULE_AUTHOR("Jonas Munsin");
 283 MODULE_DESCRIPTION("A driver for the GemTek Radio Card");
 284 MODULE_PARM(io, "i");
 285 MODULE_PARM_DESC(io, "I/O address of the GemTek card (0x20c, 0x30c, 0x24c or 0x34c)");
 286
 287 EXPORT_NO_SYMBOLS;
 288
 289 int init_module(void)
 290 {
 291         if(io==-1)
 292         {
 293                 printk(KERN_ERR "You must set an I/O address with io=0x20c, io=0x30c, io=0x24c or io=0x34c\n");
 294                 return -EINVAL;
 295         }
 296         return gemtek_init(NULL);
 297 }
 298
 299 void cleanup_module(void)
 300 {
 301         video_unregister_device(&gemtek_radio);
 302         release_region(io,4);
 303 }
 304
 305 #endif
 306
 307 /*
 308   Local variables:
 309   compile-command: "gcc -c -DMODVERSIONS -D__KERNEL__ -DMODULE -O6 -Wall -Wstrict-prototypes -I /home/blp/tmp/linux-2.1.111-rtrack/include radio-rtrack2.c"
 310   End:
 311 */