1/* 2 * linux/arch/m68k/atari/atasound.c 3 * 4 * ++Geert: Moved almost all stuff to linux/drivers/sound/ 5 * 6 * The author of atari_nosound, atari_mksound and atari_microwire_cmd is 7 * unknown. (++roman: That's me... :-) 8 * 9 * This file is subject to the terms and conditions of the GNU General Public 10 * License. See the file COPYING in the main directory of this archive 11 * for more details. 12 * 13 * 1998-05-31 ++andreas: atari_mksound rewritten to always use the envelope, 14 * no timer, atari_nosound removed. 15 * 16 */ 17 18 19#include <linux/sched.h> 20#include <linux/timer.h> 21#include <linux/major.h> 22#include <linux/fcntl.h> 23#include <linux/errno.h> 24#include <linux/mm.h> 25#include <linux/module.h> 26 27#include <asm/atarihw.h> 28#include <asm/system.h> 29#include <asm/irq.h> 30#include <asm/pgtable.h> 31#include <asm/atariints.h> 32 33 34/* 35 * stuff from the old atasound.c 36 */ 37 38void atari_microwire_cmd (int cmd) 39{ 40 tt_microwire.mask = 0x7ff; 41 tt_microwire.data = MW_LM1992_ADDR | cmd; 42 43 /* Busy wait for data being completely sent :-( */ 44 while( tt_microwire.mask != 0x7ff) 45 ; 46} 47EXPORT_SYMBOL(atari_microwire_cmd); 48 49 50/* PSG base frequency */ 51#define PSG_FREQ 125000 52/* PSG envelope base frequency times 10 */ 53#define PSG_ENV_FREQ_10 78125 54 55void atari_mksound (unsigned int hz, unsigned int ticks) 56{ 57 /* Generates sound of some frequency for some number of clock 58 ticks. */ 59 unsigned long flags; 60 unsigned char tmp; 61 int period; 62 63 local_irq_save(flags); 64 65 66 /* Disable generator A in mixer control. */ 67 sound_ym.rd_data_reg_sel = 7; 68 tmp = sound_ym.rd_data_reg_sel; 69 tmp |= 011; 70 sound_ym.wd_data = tmp; 71 72 if (hz) { 73 /* Convert from frequency value to PSG period value (base 74 frequency 125 kHz). */ 75 76 period = PSG_FREQ / hz; 77 78 if (period > 0xfff) period = 0xfff; 79 80 /* Set generator A frequency to hz. */ 81 sound_ym.rd_data_reg_sel = 0; 82 sound_ym.wd_data = period & 0xff; 83 sound_ym.rd_data_reg_sel = 1; 84 sound_ym.wd_data = (period >> 8) & 0xf; 85 if (ticks) { 86 /* Set length of envelope (max 8 sec). */ 87 int length = (ticks * PSG_ENV_FREQ_10) / HZ / 10; 88 89 if (length > 0xffff) length = 0xffff; 90 sound_ym.rd_data_reg_sel = 11; 91 sound_ym.wd_data = length & 0xff; 92 sound_ym.rd_data_reg_sel = 12; 93 sound_ym.wd_data = length >> 8; 94 /* Envelope form: max -> min single. */ 95 sound_ym.rd_data_reg_sel = 13; 96 sound_ym.wd_data = 0; 97 /* Use envelope for generator A. */ 98 sound_ym.rd_data_reg_sel = 8; 99 sound_ym.wd_data = 0x10; 100 } else { 101 /* Set generator A level to maximum, no envelope. */ 102 sound_ym.rd_data_reg_sel = 8; 103 sound_ym.wd_data = 15; 104 } 105 /* Turn on generator A in mixer control. */ 106 sound_ym.rd_data_reg_sel = 7; 107 tmp &= ~1; 108 sound_ym.wd_data = tmp; 109 } 110 local_irq_restore(flags); 111} 112