/*
|
* linux/arch/m68k/amiga/amisound.c
|
*
|
* amiga sound driver for Linux/m68k
|
*
|
* This file is subject to the terms and conditions of the GNU General Public
|
* License. See the file COPYING in the main directory of this archive
|
* for more details.
|
*/
|
|
#include <linux/jiffies.h>
|
#include <linux/timer.h>
|
#include <linux/init.h>
|
#include <linux/string.h>
|
#include <linux/module.h>
|
|
#include <asm/amigahw.h>
|
|
static unsigned short *snd_data;
|
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
|
};
|
#define DATA_SIZE ARRAY_SIZE(sine_data)
|
|
#define custom amiga_custom
|
|
/*
|
* The minimum period for audio may be modified by the frame buffer
|
* device since it depends on htotal (for OCS/ECS/AGA)
|
*/
|
|
volatile unsigned short amiga_audio_min_period = 124; /* Default for pre-OCS */
|
EXPORT_SYMBOL(amiga_audio_min_period);
|
|
#define MAX_PERIOD (65535)
|
|
|
/*
|
* Current period (set by dmasound.c)
|
*/
|
|
unsigned short amiga_audio_period = MAX_PERIOD;
|
EXPORT_SYMBOL(amiga_audio_period);
|
|
static unsigned long clock_constant;
|
|
void __init amiga_init_sound(void)
|
{
|
static struct resource beep_res = { .name = "Beep" };
|
|
snd_data = amiga_chip_alloc_res(sizeof(sine_data), &beep_res);
|
if (!snd_data) {
|
pr_crit("amiga init_sound: failed to allocate chipmem\n");
|
return;
|
}
|
memcpy (snd_data, sine_data, sizeof(sine_data));
|
|
/* setup divisor */
|
clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE;
|
|
/* without amifb, turn video off and enable high quality sound */
|
#ifndef CONFIG_FB_AMIGA
|
amifb_video_off();
|
#endif
|
}
|
|
static void nosound(struct timer_list *unused);
|
static DEFINE_TIMER(sound_timer, nosound);
|
|
void amiga_mksound( unsigned int hz, unsigned int ticks )
|
{
|
unsigned long flags;
|
|
if (!snd_data)
|
return;
|
|
local_irq_save(flags);
|
del_timer( &sound_timer );
|
|
if (hz > 20 && hz < 32767) {
|
unsigned long period = (clock_constant / hz);
|
|
if (period < amiga_audio_min_period)
|
period = amiga_audio_min_period;
|
if (period > MAX_PERIOD)
|
period = MAX_PERIOD;
|
|
/* setup pointer to data, period, length and volume */
|
custom.aud[2].audlc = snd_data;
|
custom.aud[2].audlen = sizeof(sine_data)/2;
|
custom.aud[2].audper = (unsigned short)period;
|
custom.aud[2].audvol = 32; /* 50% of maxvol */
|
|
if (ticks) {
|
sound_timer.expires = jiffies + ticks;
|
add_timer( &sound_timer );
|
}
|
|
/* turn on DMA for audio channel 2 */
|
custom.dmacon = DMAF_SETCLR | DMAF_AUD2;
|
|
} else
|
nosound( 0 );
|
|
local_irq_restore(flags);
|
}
|
|
|
static void nosound(struct timer_list *unused)
|
{
|
/* turn off DMA for audio channel 2 */
|
custom.dmacon = DMAF_AUD2;
|
/* restore period to previous value after beeping */
|
custom.aud[2].audper = amiga_audio_period;
|
}
|
