111 строки
2.6 KiB
C
111 строки
2.6 KiB
C
/*
|
|
* linux/arch/m68k/atari/atasound.c
|
|
*
|
|
* ++Geert: Moved almost all stuff to linux/drivers/sound/
|
|
*
|
|
* The author of atari_nosound, atari_mksound and atari_microwire_cmd is
|
|
* unknown. (++roman: That's me... :-)
|
|
*
|
|
* 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.
|
|
*
|
|
* 1998-05-31 ++andreas: atari_mksound rewritten to always use the envelope,
|
|
* no timer, atari_nosound removed.
|
|
*
|
|
*/
|
|
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/major.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/module.h>
|
|
|
|
#include <asm/atarihw.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/atariints.h>
|
|
|
|
|
|
/*
|
|
* stuff from the old atasound.c
|
|
*/
|
|
|
|
void atari_microwire_cmd (int cmd)
|
|
{
|
|
tt_microwire.mask = 0x7ff;
|
|
tt_microwire.data = MW_LM1992_ADDR | cmd;
|
|
|
|
/* Busy wait for data being completely sent :-( */
|
|
while( tt_microwire.mask != 0x7ff)
|
|
;
|
|
}
|
|
EXPORT_SYMBOL(atari_microwire_cmd);
|
|
|
|
|
|
/* PSG base frequency */
|
|
#define PSG_FREQ 125000
|
|
/* PSG envelope base frequency times 10 */
|
|
#define PSG_ENV_FREQ_10 78125
|
|
|
|
void atari_mksound (unsigned int hz, unsigned int ticks)
|
|
{
|
|
/* Generates sound of some frequency for some number of clock
|
|
ticks. */
|
|
unsigned long flags;
|
|
unsigned char tmp;
|
|
int period;
|
|
|
|
local_irq_save(flags);
|
|
|
|
|
|
/* Disable generator A in mixer control. */
|
|
sound_ym.rd_data_reg_sel = 7;
|
|
tmp = sound_ym.rd_data_reg_sel;
|
|
tmp |= 011;
|
|
sound_ym.wd_data = tmp;
|
|
|
|
if (hz) {
|
|
/* Convert from frequency value to PSG period value (base
|
|
frequency 125 kHz). */
|
|
|
|
period = PSG_FREQ / hz;
|
|
|
|
if (period > 0xfff) period = 0xfff;
|
|
|
|
/* Set generator A frequency to hz. */
|
|
sound_ym.rd_data_reg_sel = 0;
|
|
sound_ym.wd_data = period & 0xff;
|
|
sound_ym.rd_data_reg_sel = 1;
|
|
sound_ym.wd_data = (period >> 8) & 0xf;
|
|
if (ticks) {
|
|
/* Set length of envelope (max 8 sec). */
|
|
int length = (ticks * PSG_ENV_FREQ_10) / HZ / 10;
|
|
|
|
if (length > 0xffff) length = 0xffff;
|
|
sound_ym.rd_data_reg_sel = 11;
|
|
sound_ym.wd_data = length & 0xff;
|
|
sound_ym.rd_data_reg_sel = 12;
|
|
sound_ym.wd_data = length >> 8;
|
|
/* Envelope form: max -> min single. */
|
|
sound_ym.rd_data_reg_sel = 13;
|
|
sound_ym.wd_data = 0;
|
|
/* Use envelope for generator A. */
|
|
sound_ym.rd_data_reg_sel = 8;
|
|
sound_ym.wd_data = 0x10;
|
|
} else {
|
|
/* Set generator A level to maximum, no envelope. */
|
|
sound_ym.rd_data_reg_sel = 8;
|
|
sound_ym.wd_data = 15;
|
|
}
|
|
/* Turn on generator A in mixer control. */
|
|
sound_ym.rd_data_reg_sel = 7;
|
|
tmp &= ~1;
|
|
sound_ym.wd_data = tmp;
|
|
}
|
|
local_irq_restore(flags);
|
|
}
|