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 #include <linux/spinlock.h>
  27
  28 #ifndef CONFIG_RADIO_GEMTEK_PORT
  29 #define CONFIG_RADIO_GEMTEK_PORT -1
  30 #endif
  31
  32 static int io = CONFIG_RADIO_GEMTEK_PORT;
  33 static int users = 0;
  34 static spinlock_t lock;
  35
  36 struct gemtek_device
  37 {
  38         int port;
  39         unsigned long curfreq;
  40         int muted;
  41 };
  42
  43
  44 /* local things */
  45
  46 /* the correct way to mute the gemtek may be to write the last written
  47  * frequency || 0x10, but just writing 0x10 once seems to do it as well
  48  */
  49 static void gemtek_mute(struct gemtek_device *dev)
  50 {
  51         if(dev->muted)
  52                 return;
  53         spin_lock(&lock);
  54         outb(0x10, io);
  55         spin_unlock(&lock);
  56         dev->muted = 1;
  57 }
  58
  59 static void gemtek_unmute(struct gemtek_device *dev)
  60 {
  61         if(dev->muted == 0)
  62                 return;
  63         spin_lock(&lock);
  64         outb(0x20, io);
  65         spin_unlock(&lock);
  66         dev->muted = 0;
  67 }
  68
  69 static void zero(void)
  70 {
  71         outb_p(0x04, io);
  72         udelay(5);
  73         outb_p(0x05, io);
  74         udelay(5);
  75 }
  76
  77 static void one(void)
  78 {
  79         outb_p(0x06, io);
  80         udelay(5);
  81         outb_p(0x07, io);
  82         udelay(5);
  83 }
  84
  85 static int gemtek_setfreq(struct gemtek_device *dev, unsigned long freq)
  86 {
  87         int i;
  88
  89 /*        freq = 78.25*((float)freq/16000.0 + 10.52); */
  90
  91         freq /= 16;
  92         freq += 10520;
  93         freq *= 7825;
  94         freq /= 100000;
  95
  96         spin_lock(&lock);
  97
  98         /* 2 start bits */
  99         outb_p(0x03, io);
 100         udelay(5);
 101         outb_p(0x07, io);
 102         udelay(5);
 103
 104         /* 28 frequency bits (lsb first) */
 105         for (i = 0; i < 14; i++)
 106                 if (freq & (1 << i))
 107                         one();
 108                 else
 109                         zero();
 110         /* 36 unknown bits */
 111         for (i = 0; i < 11; i++)
 112                 zero();
 113         one();
 114         for (i = 0; i < 4; i++)
 115                 zero();
 116         one();
 117         zero();
 118
 119         /* 2 end bits */
 120         outb_p(0x03, io);
 121         udelay(5);
 122         outb_p(0x07, io);
 123         udelay(5);
 124
 125         spin_unlock(&lock);
 126
 127         return 0;
 128 }
 129
 130 int gemtek_getsigstr(struct gemtek_device *dev)
 131 {
 132         spin_lock(&lock);
 133         inb(io);
 134         udelay(5);
 135         spin_unlock(&lock);
 136         if (inb(io) & 8)                /* bit set = no signal present */
 137                 return 0;
 138         return 1;               /* signal present */
 139 }
 140
 141 static int gemtek_ioctl(struct video_device *dev, unsigned int cmd, void *arg)
 142 {
 143         struct gemtek_device *rt=dev->priv;
 144
 145         switch(cmd)
 146         {
 147                 case VIDIOCGCAP:
 148                 {
 149                         struct video_capability v;
 150                         v.type=VID_TYPE_TUNER;
 151                         v.channels=1;
 152                         v.audios=1;
 153                         /* No we don't do pictures */
 154                         v.maxwidth=0;
 155                         v.maxheight=0;
 156                         v.minwidth=0;
 157                         v.minheight=0;
 158                         strcpy(v.name, "GemTek");
 159                         if(copy_to_user(arg,&v,sizeof(v)))
 160                                 return -EFAULT;
 161                         return 0;
 162                 }
 163                 case VIDIOCGTUNER:
 164                 {
 165                         struct video_tuner v;
 166                         if(copy_from_user(&v, arg,sizeof(v))!=0)
 167                                 return -EFAULT;
 168                         if(v.tuner)     /* Only 1 tuner */
 169                                 return -EINVAL;
 170                         v.rangelow=87*16000;
 171                         v.rangehigh=108*16000;
 172                         v.flags=VIDEO_TUNER_LOW;
 173                         v.mode=VIDEO_MODE_AUTO;
 174                         v.signal=0xFFFF*gemtek_getsigstr(rt);
 175                         strcpy(v.name, "FM");
 176                         if(copy_to_user(arg,&v, sizeof(v)))
 177                                 return -EFAULT;
 178                         return 0;
 179                 }
 180                 case VIDIOCSTUNER:
 181                 {
 182                         struct video_tuner v;
 183                         if(copy_from_user(&v, arg, sizeof(v)))
 184                                 return -EFAULT;
 185                         if(v.tuner!=0)
 186                                 return -EINVAL;
 187                         /* Only 1 tuner so no setting needed ! */
 188                         return 0;
 189                 }
 190                 case VIDIOCGFREQ:
 191                         if(copy_to_user(arg, &rt->curfreq, sizeof(rt->curfreq)))
 192                                 return -EFAULT;
 193                         return 0;
 194                 case VIDIOCSFREQ:
 195                         if(copy_from_user(&rt->curfreq, arg,sizeof(rt->curfreq)))
 196                                 return -EFAULT;
 197                 /* needs to be called twice in order for getsigstr to work */
 198                         gemtek_setfreq(rt, rt->curfreq);
 199                         gemtek_setfreq(rt, rt->curfreq);
 200                         return 0;
 201                 case VIDIOCGAUDIO:
 202                 {
 203                         struct video_audio v;
 204                         memset(&v,0, sizeof(v));
 205                         v.flags|=VIDEO_AUDIO_MUTABLE;
 206                         v.volume=1;
 207                         v.step=65535;
 208                         strcpy(v.name, "Radio");
 209                         if(copy_to_user(arg,&v, sizeof(v)))
 210                                 return -EFAULT;
 211                         return 0;
 212                 }
 213                 case VIDIOCSAUDIO:
 214                 {
 215                         struct video_audio v;
 216                         if(copy_from_user(&v, arg, sizeof(v)))
 217                                 return -EFAULT;
 218                         if(v.audio)
 219                                 return -EINVAL;
 220
 221                         if(v.flags&VIDEO_AUDIO_MUTE)
 222                                 gemtek_mute(rt);
 223                         else
 224                                 gemtek_unmute(rt);
 225
 226                         return 0;
 227                 }
 228                 default:
 229                         return -ENOIOCTLCMD;
 230         }
 231 }
 232
 233 static int gemtek_open(struct video_device *dev, int flags)
 234 {
 235         if(users)
 236                 return -EBUSY;
 237         users++;
 238         MOD_INC_USE_COUNT;
 239         return 0;
 240 }
 241
 242 static void gemtek_close(struct video_device *dev)
 243 {
 244         users--;
 245         MOD_DEC_USE_COUNT;
 246 }
 247
 248 static struct gemtek_device gemtek_unit;
 249
 250 static struct video_device gemtek_radio=
 251 {
 252         "GemTek radio",
 253         VID_TYPE_TUNER,
 254         VID_HARDWARE_GEMTEK,
 255         gemtek_open,
 256         gemtek_close,
 257         NULL,   /* Can't read  (no capture ability) */
 258         NULL,   /* Can't write */
 259         NULL,   /* Can't poll */
 260         gemtek_ioctl,
 261         NULL,
 262         NULL
 263 };
 264
 265 static int __init gemtek_init(void)
 266 {
 267         if(io==-1)
 268         {
 269                 printk(KERN_ERR "You must set an I/O address with io=0x20c, io=0x30c, io=0x24c or io=0x34c (io=0x020c or io=0x248 for the combined sound/radiocard)\n");
 270                 return -EINVAL;
 271         }
 272
 273         if (check_region(io, 4))
 274         {
 275                 printk(KERN_ERR "gemtek: port 0x%x already in use\n", io);
 276                 return -EBUSY;
 277         }
 278
 279         gemtek_radio.priv=&gemtek_unit;
 280
 281         if(video_register_device(&gemtek_radio, VFL_TYPE_RADIO)==-1)
 282                 return -EINVAL;
 283
 284         request_region(io, 4, "gemtek");
 285         printk(KERN_INFO "GemTek Radio Card driver.\n");
 286
 287         spin_lock_init(&lock);
 288         /* mute card - prevents noisy bootups */
 289         outb(0x10, io);
 290         udelay(5);
 291         gemtek_unit.muted = 1;
 292
 293         /* this is _maybe_ unnecessary */
 294         outb(0x01, io);
 295
 296         return 0;
 297 }
 298
 299 MODULE_AUTHOR("Jonas Munsin");
 300 MODULE_DESCRIPTION("A driver for the GemTek Radio Card");
 301 MODULE_PARM(io, "i");
 302 MODULE_PARM_DESC(io, "I/O address of the GemTek card (0x20c, 0x30c, 0x24c or 0x34c (0x20c or 0x248 have been reported to work for the combined sound/radiocard)).");
 303
 304 EXPORT_NO_SYMBOLS;
 305
 306 static void __exit gemtek_cleanup(void)
 307 {
 308         video_unregister_device(&gemtek_radio);
 309         release_region(io,4);
 310 }
 311
 312 module_init(gemtek_init);
 313 module_exit(gemtek_cleanup);
 314
 315 /*
 316   Local variables:
 317   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"
 318   End:
 319 */