cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

atasound.c (2656B)

      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/irq.h>
     29#include <asm/atariints.h>
     30
     31
     32/*
     33 * stuff from the old atasound.c
     34 */
     35
     36void atari_microwire_cmd (int cmd)
     37{
     38	tt_microwire.mask = 0x7ff;
     39	tt_microwire.data = MW_LM1992_ADDR | cmd;
     40
     41	/* Busy wait for data being completely sent :-( */
     42	while( tt_microwire.mask != 0x7ff)
     43		;
     44}
     45EXPORT_SYMBOL(atari_microwire_cmd);
     46
     47
     48/* PSG base frequency */
     49#define	PSG_FREQ	125000
     50/* PSG envelope base frequency times 10 */
     51#define PSG_ENV_FREQ_10	78125
     52
     53void atari_mksound (unsigned int hz, unsigned int ticks)
     54{
     55	/* Generates sound of some frequency for some number of clock
     56	   ticks.  */
     57	unsigned long flags;
     58	unsigned char tmp;
     59	int period;
     60
     61	local_irq_save(flags);
     62
     63
     64	/* Disable generator A in mixer control.  */
     65	sound_ym.rd_data_reg_sel = 7;
     66	tmp = sound_ym.rd_data_reg_sel;
     67	tmp |= 011;
     68	sound_ym.wd_data = tmp;
     69
     70	if (hz) {
     71	    /* Convert from frequency value to PSG period value (base
     72	       frequency 125 kHz).  */
     73
     74	    period = PSG_FREQ / hz;
     75
     76	    if (period > 0xfff) period = 0xfff;
     77
     78	/* Set generator A frequency to hz.  */
     79	sound_ym.rd_data_reg_sel = 0;
     80	sound_ym.wd_data = period & 0xff;
     81	sound_ym.rd_data_reg_sel = 1;
     82	sound_ym.wd_data = (period >> 8) & 0xf;
     83	if (ticks) {
     84		/* Set length of envelope (max 8 sec).  */
     85		int length = (ticks * PSG_ENV_FREQ_10) / HZ / 10;
     86
     87		if (length > 0xffff) length = 0xffff;
     88		sound_ym.rd_data_reg_sel = 11;
     89		sound_ym.wd_data = length & 0xff;
     90		sound_ym.rd_data_reg_sel = 12;
     91		sound_ym.wd_data = length >> 8;
     92		/* Envelope form: max -> min single.  */
     93		sound_ym.rd_data_reg_sel = 13;
     94		sound_ym.wd_data = 0;
     95		/* Use envelope for generator A.  */
     96		sound_ym.rd_data_reg_sel = 8;
     97		sound_ym.wd_data = 0x10;
     98	} else {
     99		/* Set generator A level to maximum, no envelope.  */
    100		sound_ym.rd_data_reg_sel = 8;
    101		sound_ym.wd_data = 15;
    102	}
    103	/* Turn on generator A in mixer control.  */
    104	sound_ym.rd_data_reg_sel = 7;
    105	tmp &= ~1;
    106	sound_ym.wd_data = tmp;
    107	}
    108	local_irq_restore(flags);
    109}