/*
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/*
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* linux/amiga/amisound.c
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* linux/amiga/amisound.c
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*
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*
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* amiga sound driver for 680x0 Linux
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* amiga sound driver for 680x0 Linux
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*
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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* for more details.
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*/
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*/
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <linux/timer.h>
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#include <linux/timer.h>
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#include <asm/system.h>
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#include <asm/system.h>
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#include <asm/amigahw.h>
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#include <asm/amigahw.h>
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#include <asm/bootinfo.h>
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#include <asm/bootinfo.h>
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static u_short *snd_data = NULL;
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static u_short *snd_data = NULL;
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static const signed char sine_data[] = {
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static const signed char sine_data[] = {
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0, 39, 75, 103, 121, 127, 121, 103, 75, 39,
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0, 39, 75, 103, 121, 127, 121, 103, 75, 39,
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0, -39, -75, -103, -121, -127, -121, -103, -75, -39
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0, -39, -75, -103, -121, -127, -121, -103, -75, -39
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};
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};
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#define DATA_SIZE (sizeof(sine_data)/sizeof(sine_data[0]))
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#define DATA_SIZE (sizeof(sine_data)/sizeof(sine_data[0]))
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/*
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/*
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* The minimum period for audio may be modified by the frame buffer
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* The minimum period for audio may be modified by the frame buffer
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* device since it depends on htotal (for OCS/ECS/AGA)
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* device since it depends on htotal (for OCS/ECS/AGA)
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*/
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*/
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volatile u_short amiga_audio_min_period = 124; /* Default for pre-OCS */
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volatile u_short amiga_audio_min_period = 124; /* Default for pre-OCS */
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#define MAX_PERIOD (65535)
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#define MAX_PERIOD (65535)
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/*
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/*
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* Current period (set by dmasound.c)
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* Current period (set by dmasound.c)
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*/
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*/
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u_short amiga_audio_period = MAX_PERIOD;
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u_short amiga_audio_period = MAX_PERIOD;
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static u_long clock_constant;
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static u_long clock_constant;
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static void init_sound(void)
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static void init_sound(void)
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{
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{
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snd_data = amiga_chip_alloc(sizeof(sine_data));
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snd_data = amiga_chip_alloc(sizeof(sine_data));
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if (!snd_data) {
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if (!snd_data) {
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printk (KERN_CRIT "amiga init_sound: failed to allocate chipmem\n");
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printk (KERN_CRIT "amiga init_sound: failed to allocate chipmem\n");
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return;
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return;
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}
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}
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memcpy (snd_data, sine_data, sizeof(sine_data));
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memcpy (snd_data, sine_data, sizeof(sine_data));
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/* setup divisor */
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/* setup divisor */
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clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE;
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clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE;
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}
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}
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static void nosound( unsigned long ignored );
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static void nosound( unsigned long ignored );
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static struct timer_list sound_timer = { NULL, NULL, 0, 0, nosound };
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static struct timer_list sound_timer = { NULL, NULL, 0, 0, nosound };
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void amiga_mksound( unsigned int hz, unsigned int ticks )
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void amiga_mksound( unsigned int hz, unsigned int ticks )
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{
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{
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static int inited = 0;
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static int inited = 0;
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unsigned long flags;
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unsigned long flags;
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if (!inited) {
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if (!inited) {
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init_sound();
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init_sound();
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inited = 1;
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inited = 1;
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}
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}
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if (!snd_data)
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if (!snd_data)
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return;
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return;
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save_flags(flags);
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save_flags(flags);
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cli();
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cli();
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del_timer( &sound_timer );
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del_timer( &sound_timer );
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if (hz > 20 && hz < 32767) {
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if (hz > 20 && hz < 32767) {
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u_long period = (clock_constant / hz);
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u_long period = (clock_constant / hz);
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if (period < amiga_audio_min_period)
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if (period < amiga_audio_min_period)
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period = amiga_audio_min_period;
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period = amiga_audio_min_period;
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if (period > MAX_PERIOD)
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if (period > MAX_PERIOD)
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period = MAX_PERIOD;
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period = MAX_PERIOD;
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/* setup pointer to data, period, length and volume */
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/* setup pointer to data, period, length and volume */
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custom.aud[2].audlc = snd_data;
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custom.aud[2].audlc = snd_data;
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custom.aud[2].audlen = sizeof(sine_data)/2;
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custom.aud[2].audlen = sizeof(sine_data)/2;
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custom.aud[2].audper = (u_short)period;
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custom.aud[2].audper = (u_short)period;
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custom.aud[2].audvol = 64; /* maxvol */
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custom.aud[2].audvol = 64; /* maxvol */
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if (ticks) {
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if (ticks) {
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sound_timer.expires = jiffies + ticks;
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sound_timer.expires = jiffies + ticks;
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add_timer( &sound_timer );
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add_timer( &sound_timer );
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}
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}
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/* turn on DMA for audio channel 2 */
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/* turn on DMA for audio channel 2 */
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custom.dmacon = DMAF_SETCLR | DMAF_AUD2;
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custom.dmacon = DMAF_SETCLR | DMAF_AUD2;
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restore_flags(flags);
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restore_flags(flags);
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return;
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return;
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} else {
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} else {
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nosound( 0 );
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nosound( 0 );
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restore_flags(flags);
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restore_flags(flags);
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return;
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return;
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}
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}
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}
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}
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static void nosound( unsigned long ignored )
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static void nosound( unsigned long ignored )
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{
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{
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/* turn off DMA for audio channel 2 */
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/* turn off DMA for audio channel 2 */
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custom.dmacon = DMAF_AUD2;
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custom.dmacon = DMAF_AUD2;
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/* restore period to previous value after beeping */
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/* restore period to previous value after beeping */
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custom.aud[2].audper = amiga_audio_period;
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custom.aud[2].audper = amiga_audio_period;
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}
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}
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