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 struct timer_list mac_sound_timer =
  60                 TIMER_INITIALIZER(mac_nosound, 0, 0);
  61
  62 /*
  63  * Sort of initialize the sound chip (called from mac_mksound on the first
  64  * beep).
  65  */
  66 static void mac_init_asc( void )
  67 {
  68         int i;
  69
  70         /*
  71          * do some machine specific initialization
  72          * BTW:
  73          * the NetBSD Quadra patch identifies the Enhanced Apple Sound Chip via
  74          *      mac_asc_regs[ 0x800 ] & 0xF0 != 0
  75          * this makes no sense here, because we have to set the default sample
  76          * rate anyway if we want correct frequencies
  77          */
  78         switch ( macintosh_config->ident )
  79         {
  80                 case MAC_MODEL_IIFX:
  81                         /*
  82                          * The IIfx is always special ...
  83                          */
  84                         mac_asc_regs = ( void* )0x50010000;
  85                         break;
  86                         /*
  87                          * not sure about how correct this list is
  88                          * machines with the EASC enhanced apple sound chip
  89                          */
  90                 case MAC_MODEL_Q630:
  91                 case MAC_MODEL_P475:
  92                         mac_special_bell = mac_quadra_start_bell;
  93                         mac_asc_samplespersec = 22150;
  94                         break;
  95                 case MAC_MODEL_C660:
  96                 case MAC_MODEL_Q840:
  97                         /*
  98                          * The Quadra 660AV and 840AV use the "Singer" custom ASIC for sound I/O.
  99                          * It appears to be similar to the "AWACS" custom ASIC in the Power Mac
 100                          * [678]100.  Because Singer and AWACS may have a similar hardware
 101                          * interface, this would imply that the code in drivers/sound/dmasound.c
 102                          * for AWACS could be used as a basis for Singer support.  All we have to
 103                          * do is figure out how to do DMA on the 660AV/840AV through the PSC and
 104                          * figure out where the Singer hardware sits in memory. (I'd look in the
 105                          * vicinity of the AWACS location in a Power Mac [678]100 first, or the
 106                          * current location of the Apple Sound Chip--ASC--in other Macs.)  The
 107                          * Power Mac [678]100 info can be found in MkLinux Mach kernel sources.
 108                          *
 109                          * Quoted from Apple's Tech Info Library, article number 16405:
 110                          *   "Among desktop Macintosh computers, only the 660AV, 840AV, and Power
 111                          *   Macintosh models have 16-bit audio input and output capability
 112                          *   because of the AT&T DSP3210 hardware circuitry and the 16-bit Singer
 113                          *   codec circuitry in the AVs.  The Audio Waveform Amplifier and
 114                          *   Converter (AWAC) chip in the Power Macintosh performs the same
 115                          *   16-bit I/O functionality.  The PowerBook 500 series computers
 116                          *   support 16-bit stereo output, but only mono input."
 117                          *
 118                          *   http://til.info.apple.com/techinfo.nsf/artnum/n16405
 119                          *
 120                          * --David Kilzer
 121                          */
 122                         mac_special_bell = mac_av_start_bell;
 123                         break;
 124                 case MAC_MODEL_Q650:
 125                 case MAC_MODEL_Q700:
 126                 case MAC_MODEL_Q800:
 127                 case MAC_MODEL_Q900:
 128                 case MAC_MODEL_Q950:
 129                         /*
 130                          * Currently not implemented!
 131                          */
 132                         mac_special_bell = NULL;
 133                         break;
 134                 default:
 135                         /*
 136                          * Every switch needs a default
 137                          */
 138                         mac_special_bell = NULL;
 139                         break;
 140         }
 141
 142         /*
 143          * init the wave table with a simple triangular wave
 144          * A sine wave would sure be nicer here ...
 145          */
 146         for ( i = 0; i < 0x400; i++ )
 147         {
 148                 mac_asc_wave_tab[ i ] = i / 4;
 149                 mac_asc_wave_tab[ i + 0x400 ] = 0xFF - i / 4;
 150         }
 151         mac_asc_inited = 1;
 152 }
 153
 154 /*
 155  * Called to make noise; current single entry to the boing driver.
 156  * Does the job for simple ASC, calls other routines else.
 157  * XXX Fixme:
 158  * Should be split into asc_mksound, easc_mksound, av_mksound and
 159  * function pointer set in mac_init_asc which would be called at
 160  * init time.
 161  * _This_ is rather ugly ...
 162  */
 163 void mac_mksound( unsigned int freq, unsigned int length )
 164 {
 165         __u32 cfreq = ( freq << 5 ) / 468;
 166         __u32 flags;
 167         int i;
 168
 169         if ( mac_special_bell == NULL )
 170         {
 171                 /* Do nothing */
 172                 return;
 173         }
 174
 175         if ( !mac_asc_inited )
 176                 mac_init_asc();
 177
 178         if ( mac_special_bell )
 179         {
 180                 mac_special_bell( freq, length, 128 );
 181                 return;
 182         }
 183
 184         if ( freq < 20 || freq > 20000 || length == 0 )
 185         {
 186                 mac_nosound( 0 );
 187                 return;
 188         }
 189
 190         local_irq_save(flags);
 191
 192         del_timer( &mac_sound_timer );
 193
 194         for ( i = 0; i < 0x800; i++ )
 195                 mac_asc_regs[ i ] = 0;
 196         for ( i = 0; i < 0x800; i++ )
 197                 mac_asc_regs[ i ] = mac_asc_wave_tab[ i ];
 198
 199         for ( i = 0; i < 8; i++ )
 200                 *( __u32* )( ( __u32 )mac_asc_regs + ASC_CONTROL + 0x814 + 8 * i ) = cfreq;
 201
 202         mac_asc_regs[ 0x807 ] = 0;
 203         mac_asc_regs[ ASC_VOLUME ] = 128;
 204         mac_asc_regs[ 0x805 ] = 0;
 205         mac_asc_regs[ 0x80F ] = 0;
 206         mac_asc_regs[ ASC_MODE ] = ASC_MODE_SAMPLE;
 207         mac_asc_regs[ ASC_ENABLE ] = ASC_ENABLE_SAMPLE;
 208
 209         mac_sound_timer.expires = jiffies + length;
 210         add_timer( &mac_sound_timer );
 211
 212         local_irq_restore(flags);
 213 }
 214
 215 /*
 216  * regular ASC: stop whining ..
 217  */
 218 static void mac_nosound( unsigned long ignored )
 219 {
 220         mac_asc_regs[ ASC_ENABLE ] = 0;
 221 }
 222
 223 /*
 224  * EASC entry; init EASC, don't load wavetable, schedule 'start whining'.
 225  */
 226 static void mac_quadra_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 227 {
 228         __u32 flags;
 229
 230         /* if the bell is already ringing, ring longer */
 231         if ( mac_bell_duration > 0 )
 232         {
 233                 mac_bell_duration += length;
 234                 return;
 235         }
 236
 237         mac_bell_duration = length;
 238         mac_bell_phase = 0;
 239         mac_bell_phasepersample = ( freq * sizeof( mac_asc_wave_tab ) ) / mac_asc_samplespersec;
 240         /* this is reasonably big for small frequencies */
 241
 242         local_irq_save(flags);
 243
 244         /* set the volume */
 245         mac_asc_regs[ 0x806 ] = volume;
 246
 247         /* set up the ASC registers */
 248         if ( mac_asc_regs[ 0x801 ] != 1 )
 249         {
 250                 /* select mono mode */
 251                 mac_asc_regs[ 0x807 ] = 0;
 252                 /* select sampled sound mode */
 253                 mac_asc_regs[ 0x802 ] = 0;
 254                 /* ??? */
 255                 mac_asc_regs[ 0x801 ] = 1;
 256                 mac_asc_regs[ 0x803 ] |= 0x80;
 257                 mac_asc_regs[ 0x803 ] &= 0x7F;
 258         }
 259
 260         mac_sound_timer.function = mac_quadra_ring_bell;
 261         mac_sound_timer.expires = jiffies + 1;
 262         add_timer( &mac_sound_timer );
 263
 264         local_irq_restore(flags);
 265 }
 266
 267 /*
 268  * EASC 'start/continue whining'; I'm not sure why the above function didn't
 269  * already load the wave table, or at least call this one...
 270  * This piece keeps reloading the wave table until done.
 271  */
 272 static void mac_quadra_ring_bell( unsigned long ignored )
 273 {
 274         int     i, count = mac_asc_samplespersec / HZ;
 275         __u32 flags;
 276
 277         /*
 278          * we neither want a sound buffer overflow nor underflow, so we need to match
 279          * the number of samples per timer interrupt as exactly as possible.
 280          * using the asc interrupt will give better results in the future
 281          * ...and the possibility to use a real sample (a boingy noise, maybe...)
 282          */
 283
 284         local_irq_save(flags);
 285
 286         del_timer( &mac_sound_timer );
 287
 288         if ( mac_bell_duration-- > 0 )
 289         {
 290                 for ( i = 0; i < count; i++ )
 291                 {
 292                         mac_bell_phase += mac_bell_phasepersample;
 293                         mac_asc_regs[ 0 ] = mac_asc_wave_tab[ mac_bell_phase & ( sizeof( mac_asc_wave_tab ) - 1 ) ];
 294                 }
 295                 mac_sound_timer.expires = jiffies + 1;
 296                 add_timer( &mac_sound_timer );
 297         }
 298         else
 299                 mac_asc_regs[ 0x801 ] = 0;
 300
 301         local_irq_restore(flags);
 302 }
 303
 304 /*
 305  * AV code - please fill in.
 306  */
 307 static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 308 {
 309 }