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 | #include "atari.h" |
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 | } |
46 | EXPORT_SYMBOL(atari_microwire_cmd); |
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 | } |
111 | |