release/src-rt-6.x.4708/linux/linux-2.6.36/arch/m68k/mac/macboing.c

   1 /*
   2  *      Mac bong noise generator. Note - we ought to put a boingy noise
   3  *      here 8)
   4  *
   5  *      ----------------------------------------------------------------------
   6  *      16.11.98:
   7  *      rewrote some functions, added support for Enhanced ASC (Quadras)
   8  *      after the NetBSD asc.c console bell patch by Colin Wood/Frederick Bruck
   9  *      Juergen Mellinger (juergen.mellinger@t-online.de)
  10  */
  11
  12 #include <linux/sched.h>
  13 #include <linux/timer.h>
  14
  15 #include <asm/macintosh.h>
  16 #include <asm/mac_asc.h>
  17
  18 static int mac_asc_inited;
  19 /*
  20  * dumb triangular wave table
  21  */
  22 static __u8 mac_asc_wave_tab[ 0x800 ];
  23
  24 /*
  25  * Alan's original sine table; needs interpolating to 0x800
  26  * (hint: interpolate or hardwire [0 -> Pi/2[, it's symmetric)
  27  */
  28 static const signed char sine_data[] = {
  29         0,  39,  75,  103,  121,  127,  121,  103,  75,  39,
  30         0, -39, -75, -103, -121, -127, -121, -103, -75, -39
  31 };
  32
  33 /*
  34  * where the ASC hides ...
  35  */
  36 static volatile __u8* mac_asc_regs = ( void* )0x50F14000;
  37
  38 /*
  39  * sample rate; is this a good default value?
  40  */
  41 static unsigned long mac_asc_samplespersec = 11050;
  42 static int mac_bell_duration;
  43 static unsigned long mac_bell_phase; /* 0..2*Pi -> 0..0x800 (wavetable size) */
  44 static unsigned long mac_bell_phasepersample;
  45
  46 /*
  47  * some function protos
  48  */
  49 static void mac_init_asc( void );
  50 static void mac_nosound( unsigned long );
  51 static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
  52 static void mac_quadra_ring_bell( unsigned long );
  53 static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
  54 static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
  55
  56 /*
  57  * our timer to start/continue/stop the bell
  58  */
  59 static DEFINE_TIMER(mac_sound_timer, mac_nosound, 0, 0);
  60
  61 /*
  62  * Sort of initialize the sound chip (called from mac_mksound on the first
  63  * beep).
  64  */
  65 static void mac_init_asc( void )
  66 {
  67         int i;
  68
  69         /*
  70          * do some machine specific initialization
  71          * BTW:
  72          * the NetBSD Quadra patch identifies the Enhanced Apple Sound Chip via
  73          *      mac_asc_regs[ 0x800 ] & 0xF0 != 0
  74          * this makes no sense here, because we have to set the default sample
  75          * rate anyway if we want correct frequencies
  76          */
  77         switch ( macintosh_config->ident )
  78         {
  79                 case MAC_MODEL_IIFX:
  80                         /*
  81                          * The IIfx is always special ...
  82                          */
  83                         mac_asc_regs = ( void* )0x50010000;
  84                         break;
  85                         /*
  86                          * not sure about how correct this list is
  87                          * machines with the EASC enhanced apple sound chip
  88                          */
  89                 case MAC_MODEL_Q630:
  90                 case MAC_MODEL_P475:
  91                         mac_special_bell = mac_quadra_start_bell;
  92                         mac_asc_samplespersec = 22150;
  93                         break;
  94                 case MAC_MODEL_C660:
  95                 case MAC_MODEL_Q840:
  96                         /*
  97                          * The Quadra 660AV and 840AV use the "Singer" custom ASIC for sound I/O.
  98                          * It appears to be similar to the "AWACS" custom ASIC in the Power Mac
  99                          * [678]100.  Because Singer and AWACS may have a similar hardware
 100                          * interface, this would imply that the code in drivers/sound/dmasound.c
 101                          * for AWACS could be used as a basis for Singer support.  All we have to
 102                          * do is figure out how to do DMA on the 660AV/840AV through the PSC and
 103                          * figure out where the Singer hardware sits in memory. (I'd look in the
 104                          * vicinity of the AWACS location in a Power Mac [678]100 first, or the
 105                          * current location of the Apple Sound Chip--ASC--in other Macs.)  The
 106                          * Power Mac [678]100 info can be found in MkLinux Mach kernel sources.
 107                          *
 108                          * Quoted from Apple's Tech Info Library, article number 16405:
 109                          *   "Among desktop Macintosh computers, only the 660AV, 840AV, and Power
 110                          *   Macintosh models have 16-bit audio input and output capability
 111                          *   because of the AT&T DSP3210 hardware circuitry and the 16-bit Singer
 112                          *   codec circuitry in the AVs.  The Audio Waveform Amplifier and
 113                          *   Converter (AWAC) chip in the Power Macintosh performs the same
 114                          *   16-bit I/O functionality.  The PowerBook 500 series computers
 115                          *   support 16-bit stereo output, but only mono input."
 116                          *
 117                          *   http://til.info.apple.com/techinfo.nsf/artnum/n16405
 118                          *
 119                          * --David Kilzer
 120                          */
 121                         mac_special_bell = mac_av_start_bell;
 122                         break;
 123                 case MAC_MODEL_Q650:
 124                 case MAC_MODEL_Q700:
 125                 case MAC_MODEL_Q800:
 126                 case MAC_MODEL_Q900:
 127                 case MAC_MODEL_Q950:
 128                         /*
 129                          * Currently not implemented!
 130                          */
 131                         mac_special_bell = NULL;
 132                         break;
 133                 default:
 134                         /*
 135                          * Every switch needs a default
 136                          */
 137                         mac_special_bell = NULL;
 138                         break;
 139         }
 140
 141         /*
 142          * init the wave table with a simple triangular wave
 143          * A sine wave would sure be nicer here ...
 144          */
 145         for ( i = 0; i < 0x400; i++ )
 146         {
 147                 mac_asc_wave_tab[ i ] = i / 4;
 148                 mac_asc_wave_tab[ i + 0x400 ] = 0xFF - i / 4;
 149         }
 150         mac_asc_inited = 1;
 151 }
 152
 153 void mac_mksound( unsigned int freq, unsigned int length )
 154 {
 155         __u32 cfreq = ( freq << 5 ) / 468;
 156         unsigned long flags;
 157         int i;
 158
 159         if ( mac_special_bell == NULL )
 160         {
 161                 /* Do nothing */
 162                 return;
 163         }
 164
 165         if ( !mac_asc_inited )
 166                 mac_init_asc();
 167
 168         if ( mac_special_bell )
 169         {
 170                 mac_special_bell( freq, length, 128 );
 171                 return;
 172         }
 173
 174         if ( freq < 20 || freq > 20000 || length == 0 )
 175         {
 176                 mac_nosound( 0 );
 177                 return;
 178         }
 179
 180         local_irq_save(flags);
 181
 182         del_timer( &mac_sound_timer );
 183
 184         for ( i = 0; i < 0x800; i++ )
 185                 mac_asc_regs[ i ] = 0;
 186         for ( i = 0; i < 0x800; i++ )
 187                 mac_asc_regs[ i ] = mac_asc_wave_tab[ i ];
 188
 189         for ( i = 0; i < 8; i++ )
 190                 *( __u32* )( ( __u32 )mac_asc_regs + ASC_CONTROL + 0x814 + 8 * i ) = cfreq;
 191
 192         mac_asc_regs[ 0x807 ] = 0;
 193         mac_asc_regs[ ASC_VOLUME ] = 128;
 194         mac_asc_regs[ 0x805 ] = 0;
 195         mac_asc_regs[ 0x80F ] = 0;
 196         mac_asc_regs[ ASC_MODE ] = ASC_MODE_SAMPLE;
 197         mac_asc_regs[ ASC_ENABLE ] = ASC_ENABLE_SAMPLE;
 198
 199         mac_sound_timer.expires = jiffies + length;
 200         add_timer( &mac_sound_timer );
 201
 202         local_irq_restore(flags);
 203 }
 204
 205 /*
 206  * regular ASC: stop whining ..
 207  */
 208 static void mac_nosound( unsigned long ignored )
 209 {
 210         mac_asc_regs[ ASC_ENABLE ] = 0;
 211 }
 212
 213 /*
 214  * EASC entry; init EASC, don't load wavetable, schedule 'start whining'.
 215  */
 216 static void mac_quadra_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 217 {
 218         unsigned long flags;
 219
 220         /* if the bell is already ringing, ring longer */
 221         if ( mac_bell_duration > 0 )
 222         {
 223                 mac_bell_duration += length;
 224                 return;
 225         }
 226
 227         mac_bell_duration = length;
 228         mac_bell_phase = 0;
 229         mac_bell_phasepersample = ( freq * sizeof( mac_asc_wave_tab ) ) / mac_asc_samplespersec;
 230         /* this is reasonably big for small frequencies */
 231
 232         local_irq_save(flags);
 233
 234         /* set the volume */
 235         mac_asc_regs[ 0x806 ] = volume;
 236
 237         /* set up the ASC registers */
 238         if ( mac_asc_regs[ 0x801 ] != 1 )
 239         {
 240                 /* select mono mode */
 241                 mac_asc_regs[ 0x807 ] = 0;
 242                 /* select sampled sound mode */
 243                 mac_asc_regs[ 0x802 ] = 0;
 244                 /* ??? */
 245                 mac_asc_regs[ 0x801 ] = 1;
 246                 mac_asc_regs[ 0x803 ] |= 0x80;
 247                 mac_asc_regs[ 0x803 ] &= 0x7F;
 248         }
 249
 250         mac_sound_timer.function = mac_quadra_ring_bell;
 251         mac_sound_timer.expires = jiffies + 1;
 252         add_timer( &mac_sound_timer );
 253
 254         local_irq_restore(flags);
 255 }
 256
 257 /*
 258  * EASC 'start/continue whining'; I'm not sure why the above function didn't
 259  * already load the wave table, or at least call this one...
 260  * This piece keeps reloading the wave table until done.
 261  */
 262 static void mac_quadra_ring_bell( unsigned long ignored )
 263 {
 264         int     i, count = mac_asc_samplespersec / HZ;
 265         unsigned long flags;
 266
 267         /*
 268          * we neither want a sound buffer overflow nor underflow, so we need to match
 269          * the number of samples per timer interrupt as exactly as possible.
 270          * using the asc interrupt will give better results in the future
 271          * ...and the possibility to use a real sample (a boingy noise, maybe...)
 272          */
 273
 274         local_irq_save(flags);
 275
 276         del_timer( &mac_sound_timer );
 277
 278         if ( mac_bell_duration-- > 0 )
 279         {
 280                 for ( i = 0; i < count; i++ )
 281                 {
 282                         mac_bell_phase += mac_bell_phasepersample;
 283                         mac_asc_regs[ 0 ] = mac_asc_wave_tab[ mac_bell_phase & ( sizeof( mac_asc_wave_tab ) - 1 ) ];
 284                 }
 285                 mac_sound_timer.expires = jiffies + 1;
 286                 add_timer( &mac_sound_timer );
 287         }
 288         else
 289                 mac_asc_regs[ 0x801 ] = 0;
 290
 291         local_irq_restore(flags);
 292 }
 293
 294 /*
 295  * AV code - please fill in.
 296  */
 297 static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 298 {
 299 }