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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Adrian Bunka3b20042008-02-04 22:30:26 -080025#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
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}
Adrian Bunka3b20042008-02-04 22:30:26 -080047EXPORT_SYMBOL(atari_microwire_cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
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}