Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *      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( unsigned long );

static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );

static void mac_quadra_ring_bell( unsigned long );

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, 0, 0);

/*

 * 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."

                         *

                         *   http://til.info.apple.com/techinfo.nsf/artnum/n16405

                         *

                         * --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;

        __u32 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( unsigned long ignored )

{

        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 )

{

        __u32 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( unsigned long ignored )

{

        int     i, count = mac_asc_samplespersec / HZ;

        __u32 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 )

{

}