// SPDX-License-Identifier: GPL-2.0
/*
* Mac bong noise generator. Note - we ought to put a boingy noise
* here 8)
*
* ----------------------------------------------------------------------
* 16.11.98:
* rewrote some functions, added support for Enhanced ASC (Quadras)
* after the NetBSD asc.c console bell patch by Colin Wood/Frederick Bruck
* Juergen Mellinger (juergen.mellinger@t-online.de)
*/
#include <linux/sched.h>
#include <linux/timer.h>
#include <asm/macintosh.h>
#include <asm/mac_asc.h>
static int mac_asc_inited;
/*
* dumb triangular wave table
*/
static __u8 mac_asc_wave_tab[ 0x800 ];
/*
* Alan's original sine table; needs interpolating to 0x800
* (hint: interpolate or hardwire [0 -> Pi/2[, it's symmetric)
*/
static const signed char sine_data[] = {
0, 39, 75, 103, 121, 127, 121, 103, 75, 39,
0, -39, -75, -103, -121, -127, -121, -103, -75, -39
};
/*
* where the ASC hides ...
*/
static volatile __u8* mac_asc_regs = ( void* )0x50F14000;
/*
* sample rate; is this a good default value?
*/
static unsigned long mac_asc_samplespersec = 11050;
static int mac_bell_duration;
static unsigned long mac_bell_phase; /* 0..2*Pi -> 0..0x800 (wavetable size) */
static unsigned long mac_bell_phasepersample;
/*
* some function protos
*/
static void mac_init_asc( void );
static void mac_nosound(struct timer_list *);
static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
static void mac_quadra_ring_bell(struct timer_list *);
static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
/*
* our timer to start/continue/stop the bell
*/
static DEFINE_TIMER(mac_sound_timer, mac_nosound);
/*
* Sort of initialize the sound chip (called from mac_mksound on the first
* beep).
*/
static void mac_init_asc( void )
{
int i;
/*
* do some machine specific initialization
* BTW:
* the NetBSD Quadra patch identifies the Enhanced Apple Sound Chip via
* mac_asc_regs[ 0x800 ] & 0xF0 != 0
* this makes no sense here, because we have to set the default sample
* rate anyway if we want correct frequencies
*/
switch ( macintosh_config->ident )
{
case MAC_MODEL_IIFX:
/*
* The IIfx is always special ...
*/
mac_asc_regs = ( void* )0x50010000;
break;
/*
* not sure about how correct this list is
* machines with the EASC enhanced apple sound chip
*/
case MAC_MODEL_Q630:
case MAC_MODEL_P475:
mac_special_bell = mac_quadra_start_bell;
mac_asc_samplespersec = 22150;
break;
case MAC_MODEL_C660:
case MAC_MODEL_Q840:
/*
* The Quadra 660AV and 840AV use the "Singer" custom ASIC for sound I/O.
* It appears to be similar to the "AWACS" custom ASIC in the Power Mac
* [678]100. Because Singer and AWACS may have a similar hardware
* interface, this would imply that the code in drivers/sound/dmasound.c
* for AWACS could be used as a basis for Singer support. All we have to
* do is figure out how to do DMA on the 660AV/840AV through the PSC and
* figure out where the Singer hardware sits in memory. (I'd look in the
* vicinity of the AWACS location in a Power Mac [678]100 first, or the
* current location of the Apple Sound Chip--ASC--in other Macs.) The
* Power Mac [678]100 info can be found in MkLinux Mach kernel sources.
*
* Quoted from Apple's Tech Info Library, article number 16405:
* "Among desktop Macintosh computers, only the 660AV, 840AV, and Power
* Macintosh models have 16-bit audio input and output capability
* because of the AT&T DSP3210 hardware circuitry and the 16-bit Singer
* codec circuitry in the AVs. The Audio Waveform Amplifier and
* Converter (AWAC) chip in the Power Macintosh performs the same
* 16-bit I/O functionality. The PowerBook 500 series computers
* support 16-bit stereo output, but only mono input."
*
* Technical Information Library (TIL) article number 16405.
* https://support.apple.com/kb/TA32601
*
* --David Kilzer
*/
mac_special_bell = mac_av_start_bell;
break;
case MAC_MODEL_Q650:
case MAC_MODEL_Q700:
case MAC_MODEL_Q800:
case MAC_MODEL_Q900:
case MAC_MODEL_Q950:
/*
* Currently not implemented!
*/
mac_special_bell = NULL;
break;
default:
/*
* Every switch needs a default
*/
mac_special_bell = NULL;
break;
}
/*
* init the wave table with a simple triangular wave
* A sine wave would sure be nicer here ...
*/
for ( i = 0; i < 0x400; i++ )
{
mac_asc_wave_tab[ i ] = i / 4;
mac_asc_wave_tab[ i + 0x400 ] = 0xFF - i / 4;
}
mac_asc_inited = 1;
}
/*
* Called to make noise; current single entry to the boing driver.
* Does the job for simple ASC, calls other routines else.
* XXX Fixme:
* Should be split into asc_mksound, easc_mksound, av_mksound and
* function pointer set in mac_init_asc which would be called at
* init time.
* _This_ is rather ugly ...
*/
void mac_mksound( unsigned int freq, unsigned int length )
{
__u32 cfreq = ( freq << 5 ) / 468;
unsigned long flags;
int i;
if ( mac_special_bell == NULL )
{
/* Do nothing */
return;
}
if ( !mac_asc_inited )
mac_init_asc();
if ( mac_special_bell )
{
mac_special_bell( freq, length, 128 );
return;
}
if ( freq < 20 || freq > 20000 || length == 0 )
{
mac_nosound( 0 );
return;
}
local_irq_save(flags);
del_timer( &mac_sound_timer );
for ( i = 0; i < 0x800; i++ )
mac_asc_regs[ i ] = 0;
for ( i = 0; i < 0x800; i++ )
mac_asc_regs[ i ] = mac_asc_wave_tab[ i ];
for ( i = 0; i < 8; i++ )
*( __u32* )( ( __u32 )mac_asc_regs + ASC_CONTROL + 0x814 + 8 * i ) = cfreq;
mac_asc_regs[ 0x807 ] = 0;
mac_asc_regs[ ASC_VOLUME ] = 128;
mac_asc_regs[ 0x805 ] = 0;
mac_asc_regs[ 0x80F ] = 0;
mac_asc_regs[ ASC_MODE ] = ASC_MODE_SAMPLE;
mac_asc_regs[ ASC_ENABLE ] = ASC_ENABLE_SAMPLE;
mac_sound_timer.expires = jiffies + length;
add_timer( &mac_sound_timer );
local_irq_restore(flags);
}
/*
* regular ASC: stop whining ..
*/
static void mac_nosound(struct timer_list *unused)
{
mac_asc_regs[ ASC_ENABLE ] = 0;
}
/*
* EASC entry; init EASC, don't load wavetable, schedule 'start whining'.
*/
static void mac_quadra_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
{
unsigned long flags;
/* if the bell is already ringing, ring longer */
if ( mac_bell_duration > 0 )
{
mac_bell_duration += length;
return;
}
mac_bell_duration = length;
mac_bell_phase = 0;
mac_bell_phasepersample = ( freq * sizeof( mac_asc_wave_tab ) ) / mac_asc_samplespersec;
/* this is reasonably big for small frequencies */
local_irq_save(flags);
/* set the volume */
mac_asc_regs[ 0x806 ] = volume;
/* set up the ASC registers */
if ( mac_asc_regs[ 0x801 ] != 1 )
{
/* select mono mode */
mac_asc_regs[ 0x807 ] = 0;
/* select sampled sound mode */
mac_asc_regs[ 0x802 ] = 0;
/* ??? */
mac_asc_regs[ 0x801 ] = 1;
mac_asc_regs[ 0x803 ] |= 0x80;
mac_asc_regs[ 0x803 ] &= 0x7F;
}
mac_sound_timer.function = mac_quadra_ring_bell;
mac_sound_timer.expires = jiffies + 1;
add_timer( &mac_sound_timer );
local_irq_restore(flags);
}
/*
* EASC 'start/continue whining'; I'm not sure why the above function didn't
* already load the wave table, or at least call this one...
* This piece keeps reloading the wave table until done.
*/
static void mac_quadra_ring_bell(struct timer_list *unused)
{
int i, count = mac_asc_samplespersec / HZ;
unsigned long flags;
/*
* we neither want a sound buffer overflow nor underflow, so we need to match
* the number of samples per timer interrupt as exactly as possible.
* using the asc interrupt will give better results in the future
* ...and the possibility to use a real sample (a boingy noise, maybe...)
*/
local_irq_save(flags);
del_timer( &mac_sound_timer );
if ( mac_bell_duration-- > 0 )
{
for ( i = 0; i < count; i++ )
{
mac_bell_phase += mac_bell_phasepersample;
mac_asc_regs[ 0 ] = mac_asc_wave_tab[ mac_bell_phase & ( sizeof( mac_asc_wave_tab ) - 1 ) ];
}
mac_sound_timer.expires = jiffies + 1;
add_timer( &mac_sound_timer );
}
else
mac_asc_regs[ 0x801 ] = 0;
local_irq_restore(flags);
}
/*
* AV code - please fill in.
*/
static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
{
}