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- /*
- * 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);
- }
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