/* * 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/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); }