arch/m68k/mac/macboing.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *      Mac bong noise generator. Note - we ought to put a boingy noise
   4  *      here 8)
   5  *
   6  *      ----------------------------------------------------------------------
   7  *      16.11.98:
   8  *      rewrote some functions, added support for Enhanced ASC (Quadras)
   9  *      after the NetBSD asc.c console bell patch by Colin Wood/Frederick Bruck
  10  *      Juergen Mellinger (juergen.mellinger@t-online.de)
  11  */
  12
  13 #include <linux/sched.h>
  14 #include <linux/timer.h>
  15
  16 #include <asm/macintosh.h>
  17 #include <asm/mac_asc.h>
  18
  19 static int mac_asc_inited;
  20 /*
  21  * dumb triangular wave table
  22  */
  23 static __u8 mac_asc_wave_tab[ 0x800 ];
  24
  25 /*
  26  * Alan's original sine table; needs interpolating to 0x800
  27  * (hint: interpolate or hardwire [0 -> Pi/2[, it's symmetric)
  28  */
  29 static const signed char sine_data[] = {
  30         0,  39,  75,  103,  121,  127,  121,  103,  75,  39,
  31         0, -39, -75, -103, -121, -127, -121, -103, -75, -39
  32 };
  33
  34 /*
  35  * where the ASC hides ...
  36  */
  37 static volatile __u8* mac_asc_regs = ( void* )0x50F14000;
  38
  39 /*
  40  * sample rate; is this a good default value?
  41  */
  42 static unsigned long mac_asc_samplespersec = 11050;
  43 static int mac_bell_duration;
  44 static unsigned long mac_bell_phase; /* 0..2*Pi -> 0..0x800 (wavetable size) */
  45 static unsigned long mac_bell_phasepersample;
  46
  47 /*
  48  * some function protos
  49  */
  50 static void mac_init_asc( void );
  51 static void mac_nosound(struct timer_list *);
  52 static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
  53 static void mac_quadra_ring_bell(struct timer_list *);
  54 static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
  55 static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
  56
  57 /*
  58  * our timer to start/continue/stop the bell
  59  */
  60 static DEFINE_TIMER(mac_sound_timer, mac_nosound);
  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                          *   Technical Information Library (TIL) article number 16405.
 119                          *   https://support.apple.com/kb/TA32601
 120                          *
 121                          * --David Kilzer
 122                          */
 123                         mac_special_bell = mac_av_start_bell;
 124                         break;
 125                 case MAC_MODEL_Q650:
 126                 case MAC_MODEL_Q700:
 127                 case MAC_MODEL_Q800:
 128                 case MAC_MODEL_Q900:
 129                 case MAC_MODEL_Q950:
 130                         /*
 131                          * Currently not implemented!
 132                          */
 133                         mac_special_bell = NULL;
 134                         break;
 135                 default:
 136                         /*
 137                          * Every switch needs a default
 138                          */
 139                         mac_special_bell = NULL;
 140                         break;
 141         }
 142
 143         /*
 144          * init the wave table with a simple triangular wave
 145          * A sine wave would sure be nicer here ...
 146          */
 147         for ( i = 0; i < 0x400; i++ )
 148         {
 149                 mac_asc_wave_tab[ i ] = i / 4;
 150                 mac_asc_wave_tab[ i + 0x400 ] = 0xFF - i / 4;
 151         }
 152         mac_asc_inited = 1;
 153 }
 154
 155 /*
 156  * Called to make noise; current single entry to the boing driver.
 157  * Does the job for simple ASC, calls other routines else.
 158  * XXX Fixme:
 159  * Should be split into asc_mksound, easc_mksound, av_mksound and
 160  * function pointer set in mac_init_asc which would be called at
 161  * init time.
 162  * _This_ is rather ugly ...
 163  */
 164 void mac_mksound( unsigned int freq, unsigned int length )
 165 {
 166         __u32 cfreq = ( freq << 5 ) / 468;
 167         unsigned long flags;
 168         int i;
 169
 170         if ( mac_special_bell == NULL )
 171         {
 172                 /* Do nothing */
 173                 return;
 174         }
 175
 176         if ( !mac_asc_inited )
 177                 mac_init_asc();
 178
 179         if ( mac_special_bell )
 180         {
 181                 mac_special_bell( freq, length, 128 );
 182                 return;
 183         }
 184
 185         if ( freq < 20 || freq > 20000 || length == 0 )
 186         {
 187                 mac_nosound( 0 );
 188                 return;
 189         }
 190
 191         local_irq_save(flags);
 192
 193         del_timer( &mac_sound_timer );
 194
 195         for ( i = 0; i < 0x800; i++ )
 196                 mac_asc_regs[ i ] = 0;
 197         for ( i = 0; i < 0x800; i++ )
 198                 mac_asc_regs[ i ] = mac_asc_wave_tab[ i ];
 199
 200         for ( i = 0; i < 8; i++ )
 201                 *( __u32* )( ( __u32 )mac_asc_regs + ASC_CONTROL + 0x814 + 8 * i ) = cfreq;
 202
 203         mac_asc_regs[ 0x807 ] = 0;
 204         mac_asc_regs[ ASC_VOLUME ] = 128;
 205         mac_asc_regs[ 0x805 ] = 0;
 206         mac_asc_regs[ 0x80F ] = 0;
 207         mac_asc_regs[ ASC_MODE ] = ASC_MODE_SAMPLE;
 208         mac_asc_regs[ ASC_ENABLE ] = ASC_ENABLE_SAMPLE;
 209
 210         mac_sound_timer.expires = jiffies + length;
 211         add_timer( &mac_sound_timer );
 212
 213         local_irq_restore(flags);
 214 }
 215
 216 /*
 217  * regular ASC: stop whining ..
 218  */
 219 static void mac_nosound(struct timer_list *unused)
 220 {
 221         mac_asc_regs[ ASC_ENABLE ] = 0;
 222 }
 223
 224 /*
 225  * EASC entry; init EASC, don't load wavetable, schedule 'start whining'.
 226  */
 227 static void mac_quadra_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 228 {
 229         unsigned long flags;
 230
 231         /* if the bell is already ringing, ring longer */
 232         if ( mac_bell_duration > 0 )
 233         {
 234                 mac_bell_duration += length;
 235                 return;
 236         }
 237
 238         mac_bell_duration = length;
 239         mac_bell_phase = 0;
 240         mac_bell_phasepersample = ( freq * sizeof( mac_asc_wave_tab ) ) / mac_asc_samplespersec;
 241         /* this is reasonably big for small frequencies */
 242
 243         local_irq_save(flags);
 244
 245         /* set the volume */
 246         mac_asc_regs[ 0x806 ] = volume;
 247
 248         /* set up the ASC registers */
 249         if ( mac_asc_regs[ 0x801 ] != 1 )
 250         {
 251                 /* select mono mode */
 252                 mac_asc_regs[ 0x807 ] = 0;
 253                 /* select sampled sound mode */
 254                 mac_asc_regs[ 0x802 ] = 0;
 255                 /* ??? */
 256                 mac_asc_regs[ 0x801 ] = 1;
 257                 mac_asc_regs[ 0x803 ] |= 0x80;
 258                 mac_asc_regs[ 0x803 ] &= 0x7F;
 259         }
 260
 261         mac_sound_timer.function = mac_quadra_ring_bell;
 262         mac_sound_timer.expires = jiffies + 1;
 263         add_timer( &mac_sound_timer );
 264
 265         local_irq_restore(flags);
 266 }
 267
 268 /*
 269  * EASC 'start/continue whining'; I'm not sure why the above function didn't
 270  * already load the wave table, or at least call this one...
 271  * This piece keeps reloading the wave table until done.
 272  */
 273 static void mac_quadra_ring_bell(struct timer_list *unused)
 274 {
 275         int     i, count = mac_asc_samplespersec / HZ;
 276         unsigned long flags;
 277
 278         /*
 279          * we neither want a sound buffer overflow nor underflow, so we need to match
 280          * the number of samples per timer interrupt as exactly as possible.
 281          * using the asc interrupt will give better results in the future
 282          * ...and the possibility to use a real sample (a boingy noise, maybe...)
 283          */
 284
 285         local_irq_save(flags);
 286
 287         del_timer( &mac_sound_timer );
 288
 289         if ( mac_bell_duration-- > 0 )
 290         {
 291                 for ( i = 0; i < count; i++ )
 292                 {
 293                         mac_bell_phase += mac_bell_phasepersample;
 294                         mac_asc_regs[ 0 ] = mac_asc_wave_tab[ mac_bell_phase & ( sizeof( mac_asc_wave_tab ) - 1 ) ];
 295                 }
 296                 mac_sound_timer.expires = jiffies + 1;
 297                 add_timer( &mac_sound_timer );
 298         }
 299         else
 300                 mac_asc_regs[ 0x801 ] = 0;
 301
 302         local_irq_restore(flags);
 303 }
 304
 305 /*
 306  * AV code - please fill in.
 307  */
 308 static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 309 {
 310 }