Commit | Line | Data |
---|---|---|
1da177e4 LT |
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> | |
a3b2004a | 25 | #include <linux/module.h> |
1da177e4 LT |
26 | |
27 | #include <asm/atarihw.h> | |
1da177e4 LT |
28 | #include <asm/irq.h> |
29 | #include <asm/pgtable.h> | |
30 | #include <asm/atariints.h> | |
31 | ||
32 | ||
33 | /* | |
34 | * stuff from the old atasound.c | |
35 | */ | |
36 | ||
37 | void atari_microwire_cmd (int cmd) | |
38 | { | |
39 | tt_microwire.mask = 0x7ff; | |
40 | tt_microwire.data = MW_LM1992_ADDR | cmd; | |
41 | ||
42 | /* Busy wait for data being completely sent :-( */ | |
43 | while( tt_microwire.mask != 0x7ff) | |
44 | ; | |
45 | } | |
a3b2004a | 46 | EXPORT_SYMBOL(atari_microwire_cmd); |
1da177e4 LT |
47 | |
48 | ||
49 | /* PSG base frequency */ | |
50 | #define PSG_FREQ 125000 | |
51 | /* PSG envelope base frequency times 10 */ | |
52 | #define PSG_ENV_FREQ_10 78125 | |
53 | ||
54 | void atari_mksound (unsigned int hz, unsigned int ticks) | |
55 | { | |
56 | /* Generates sound of some frequency for some number of clock | |
57 | ticks. */ | |
58 | unsigned long flags; | |
59 | unsigned char tmp; | |
60 | int period; | |
61 | ||
62 | local_irq_save(flags); | |
63 | ||
64 | ||
65 | /* Disable generator A in mixer control. */ | |
66 | sound_ym.rd_data_reg_sel = 7; | |
67 | tmp = sound_ym.rd_data_reg_sel; | |
68 | tmp |= 011; | |
69 | sound_ym.wd_data = tmp; | |
70 | ||
71 | if (hz) { | |
72 | /* Convert from frequency value to PSG period value (base | |
73 | frequency 125 kHz). */ | |
74 | ||
75 | period = PSG_FREQ / hz; | |
76 | ||
77 | if (period > 0xfff) period = 0xfff; | |
78 | ||
79 | /* Set generator A frequency to hz. */ | |
80 | sound_ym.rd_data_reg_sel = 0; | |
81 | sound_ym.wd_data = period & 0xff; | |
82 | sound_ym.rd_data_reg_sel = 1; | |
83 | sound_ym.wd_data = (period >> 8) & 0xf; | |
84 | if (ticks) { | |
85 | /* Set length of envelope (max 8 sec). */ | |
86 | int length = (ticks * PSG_ENV_FREQ_10) / HZ / 10; | |
87 | ||
88 | if (length > 0xffff) length = 0xffff; | |
89 | sound_ym.rd_data_reg_sel = 11; | |
90 | sound_ym.wd_data = length & 0xff; | |
91 | sound_ym.rd_data_reg_sel = 12; | |
92 | sound_ym.wd_data = length >> 8; | |
93 | /* Envelope form: max -> min single. */ | |
94 | sound_ym.rd_data_reg_sel = 13; | |
95 | sound_ym.wd_data = 0; | |
96 | /* Use envelope for generator A. */ | |
97 | sound_ym.rd_data_reg_sel = 8; | |
98 | sound_ym.wd_data = 0x10; | |
99 | } else { | |
100 | /* Set generator A level to maximum, no envelope. */ | |
101 | sound_ym.rd_data_reg_sel = 8; | |
102 | sound_ym.wd_data = 15; | |
103 | } | |
104 | /* Turn on generator A in mixer control. */ | |
105 | sound_ym.rd_data_reg_sel = 7; | |
106 | tmp &= ~1; | |
107 | sound_ym.wd_data = tmp; | |
108 | } | |
109 | local_irq_restore(flags); | |
110 | } |