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 #include "mac.h"
  20
  21 static int mac_asc_inited;
  22 /*
  23  * dumb triangular wave table
  24  */
  25 static __u8 mac_asc_wave_tab[ 0x800 ];
  26
  27 /*
  28  * where the ASC hides ...
  29  */
  30 static volatile __u8* mac_asc_regs = ( void* )0x50F14000;
  31
  32 /*
  33  * sample rate; is this a good default value?
  34  */
  35 static unsigned long mac_asc_samplespersec = 11050;
  36 static int mac_bell_duration;
  37 static unsigned long mac_bell_phase; /* 0..2*Pi -> 0..0x800 (wavetable size) */
  38 static unsigned long mac_bell_phasepersample;
  39
  40 /*
  41  * some function protos
  42  */
  43 static void mac_init_asc( void );
  44 static void mac_nosound(struct timer_list *);
  45 static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
  46 static void mac_quadra_ring_bell(struct timer_list *);
  47 static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
  48 static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
  49
  50 /*
  51  * our timer to start/continue/stop the bell
  52  */
  53 static DEFINE_TIMER(mac_sound_timer, mac_nosound);
  54
  55 /*
  56  * Sort of initialize the sound chip (called from mac_mksound on the first
  57  * beep).
  58  */
  59 static void mac_init_asc( void )
  60 {
  61         int i;
  62
  63         /*
  64          * do some machine specific initialization
  65          * BTW:
  66          * the NetBSD Quadra patch identifies the Enhanced Apple Sound Chip via
  67          *      mac_asc_regs[ 0x800 ] & 0xF0 != 0
  68          * this makes no sense here, because we have to set the default sample
  69          * rate anyway if we want correct frequencies
  70          */
  71         switch ( macintosh_config->ident )
  72         {
  73                 case MAC_MODEL_IIFX:
  74                         /*
  75                          * The IIfx is always special ...
  76                          */
  77                         mac_asc_regs = ( void* )0x50010000;
  78                         break;
  79                         /*
  80                          * not sure about how correct this list is
  81                          * machines with the EASC enhanced apple sound chip
  82                          */
  83                 case MAC_MODEL_Q630:
  84                 case MAC_MODEL_P475:
  85                         mac_special_bell = mac_quadra_start_bell;
  86                         mac_asc_samplespersec = 22150;
  87                         break;
  88                 case MAC_MODEL_C660:
  89                 case MAC_MODEL_Q840:
  90                         /*
  91                          * The Quadra 660AV and 840AV use the "Singer" custom ASIC for sound I/O.
  92                          * It appears to be similar to the "AWACS" custom ASIC in the Power Mac
  93                          * [678]100.  Because Singer and AWACS may have a similar hardware
  94                          * interface, this would imply that the code in drivers/sound/dmasound.c
  95                          * for AWACS could be used as a basis for Singer support.  All we have to
  96                          * do is figure out how to do DMA on the 660AV/840AV through the PSC and
  97                          * figure out where the Singer hardware sits in memory. (I'd look in the
  98                          * vicinity of the AWACS location in a Power Mac [678]100 first, or the
  99                          * current location of the Apple Sound Chip--ASC--in other Macs.)  The
 100                          * Power Mac [678]100 info can be found in MkLinux Mach kernel sources.
 101                          *
 102                          * Quoted from Apple's Tech Info Library, article number 16405:
 103                          *   "Among desktop Macintosh computers, only the 660AV, 840AV, and Power
 104                          *   Macintosh models have 16-bit audio input and output capability
 105                          *   because of the AT&T DSP3210 hardware circuitry and the 16-bit Singer
 106                          *   codec circuitry in the AVs.  The Audio Waveform Amplifier and
 107                          *   Converter (AWAC) chip in the Power Macintosh performs the same
 108                          *   16-bit I/O functionality.  The PowerBook 500 series computers
 109                          *   support 16-bit stereo output, but only mono input."
 110                          *
 111                          *   Technical Information Library (TIL) article number 16405.
 112                          *   https://support.apple.com/kb/TA32601
 113                          *
 114                          * --David Kilzer
 115                          */
 116                         mac_special_bell = mac_av_start_bell;
 117                         break;
 118                 case MAC_MODEL_Q650:
 119                 case MAC_MODEL_Q700:
 120                 case MAC_MODEL_Q800:
 121                 case MAC_MODEL_Q900:
 122                 case MAC_MODEL_Q950:
 123                         /*
 124                          * Currently not implemented!
 125                          */
 126                         mac_special_bell = NULL;
 127                         break;
 128                 default:
 129                         /*
 130                          * Every switch needs a default
 131                          */
 132                         mac_special_bell = NULL;
 133                         break;
 134         }
 135
 136         /*
 137          * init the wave table with a simple triangular wave
 138          * A sine wave would sure be nicer here ...
 139          */
 140         for ( i = 0; i < 0x400; i++ )
 141         {
 142                 mac_asc_wave_tab[ i ] = i / 4;
 143                 mac_asc_wave_tab[ i + 0x400 ] = 0xFF - i / 4;
 144         }
 145         mac_asc_inited = 1;
 146 }
 147
 148 /*
 149  * Called to make noise; current single entry to the boing driver.
 150  * Does the job for simple ASC, calls other routines else.
 151  * XXX Fixme:
 152  * Should be split into asc_mksound, easc_mksound, av_mksound and
 153  * function pointer set in mac_init_asc which would be called at
 154  * init time.
 155  * _This_ is rather ugly ...
 156  */
 157 void mac_mksound( unsigned int freq, unsigned int length )
 158 {
 159         __u32 cfreq = ( freq << 5 ) / 468;
 160         unsigned long flags;
 161         int i;
 162
 163         if ( mac_special_bell == NULL )
 164         {
 165                 /* Do nothing */
 166                 return;
 167         }
 168
 169         if ( !mac_asc_inited )
 170                 mac_init_asc();
 171
 172         if ( mac_special_bell )
 173         {
 174                 mac_special_bell( freq, length, 128 );
 175                 return;
 176         }
 177
 178         if ( freq < 20 || freq > 20000 || length == 0 )
 179         {
 180                 mac_nosound( 0 );
 181                 return;
 182         }
 183
 184         local_irq_save(flags);
 185
 186         del_timer( &mac_sound_timer );
 187
 188         for ( i = 0; i < 0x800; i++ )
 189                 mac_asc_regs[ i ] = 0;
 190         for ( i = 0; i < 0x800; i++ )
 191                 mac_asc_regs[ i ] = mac_asc_wave_tab[ i ];
 192
 193         for ( i = 0; i < 8; i++ )
 194                 *( __u32* )( ( __u32 )mac_asc_regs + ASC_CONTROL + 0x814 + 8 * i ) = cfreq;
 195
 196         mac_asc_regs[ 0x807 ] = 0;
 197         mac_asc_regs[ ASC_VOLUME ] = 128;
 198         mac_asc_regs[ 0x805 ] = 0;
 199         mac_asc_regs[ 0x80F ] = 0;
 200         mac_asc_regs[ ASC_MODE ] = ASC_MODE_SAMPLE;
 201         mac_asc_regs[ ASC_ENABLE ] = ASC_ENABLE_SAMPLE;
 202
 203         mac_sound_timer.expires = jiffies + length;
 204         add_timer( &mac_sound_timer );
 205
 206         local_irq_restore(flags);
 207 }
 208
 209 /*
 210  * regular ASC: stop whining ..
 211  */
 212 static void mac_nosound(struct timer_list *unused)
 213 {
 214         mac_asc_regs[ ASC_ENABLE ] = 0;
 215 }
 216
 217 /*
 218  * EASC entry; init EASC, don't load wavetable, schedule 'start whining'.
 219  */
 220 static void mac_quadra_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 221 {
 222         unsigned long flags;
 223
 224         /* if the bell is already ringing, ring longer */
 225         if ( mac_bell_duration > 0 )
 226         {
 227                 mac_bell_duration += length;
 228                 return;
 229         }
 230
 231         mac_bell_duration = length;
 232         mac_bell_phase = 0;
 233         mac_bell_phasepersample = ( freq * sizeof( mac_asc_wave_tab ) ) / mac_asc_samplespersec;
 234         /* this is reasonably big for small frequencies */
 235
 236         local_irq_save(flags);
 237
 238         /* set the volume */
 239         mac_asc_regs[ 0x806 ] = volume;
 240
 241         /* set up the ASC registers */
 242         if ( mac_asc_regs[ 0x801 ] != 1 )
 243         {
 244                 /* select mono mode */
 245                 mac_asc_regs[ 0x807 ] = 0;
 246                 /* select sampled sound mode */
 247                 mac_asc_regs[ 0x802 ] = 0;
 248                 /* ??? */
 249                 mac_asc_regs[ 0x801 ] = 1;
 250                 mac_asc_regs[ 0x803 ] |= 0x80;
 251                 mac_asc_regs[ 0x803 ] &= 0x7F;
 252         }
 253
 254         mac_sound_timer.function = mac_quadra_ring_bell;
 255         mac_sound_timer.expires = jiffies + 1;
 256         add_timer( &mac_sound_timer );
 257
 258         local_irq_restore(flags);
 259 }
 260
 261 /*
 262  * EASC 'start/continue whining'; I'm not sure why the above function didn't
 263  * already load the wave table, or at least call this one...
 264  * This piece keeps reloading the wave table until done.
 265  */
 266 static void mac_quadra_ring_bell(struct timer_list *unused)
 267 {
 268         int     i, count = mac_asc_samplespersec / HZ;
 269         unsigned long flags;
 270
 271         /*
 272          * we neither want a sound buffer overflow nor underflow, so we need to match
 273          * the number of samples per timer interrupt as exactly as possible.
 274          * using the asc interrupt will give better results in the future
 275          * ...and the possibility to use a real sample (a boingy noise, maybe...)
 276          */
 277
 278         local_irq_save(flags);
 279
 280         del_timer( &mac_sound_timer );
 281
 282         if ( mac_bell_duration-- > 0 )
 283         {
 284                 for ( i = 0; i < count; i++ )
 285                 {
 286                         mac_bell_phase += mac_bell_phasepersample;
 287                         mac_asc_regs[ 0 ] = mac_asc_wave_tab[ mac_bell_phase & ( sizeof( mac_asc_wave_tab ) - 1 ) ];
 288                 }
 289                 mac_sound_timer.expires = jiffies + 1;
 290                 add_timer( &mac_sound_timer );
 291         }
 292         else
 293                 mac_asc_regs[ 0x801 ] = 0;
 294
 295         local_irq_restore(flags);
 296 }
 297
 298 /*
 299  * AV code - please fill in.
 300  */
 301 static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
 302 {
 303 }