Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/arch/m68k/amiga/amisound.c | |
3 | * | |
4 | * amiga sound driver for Linux/m68k | |
5 | * | |
6 | * This file is subject to the terms and conditions of the GNU General Public | |
7 | * License. See the file COPYING in the main directory of this archive | |
8 | * for more details. | |
9 | */ | |
10 | ||
1da177e4 LT |
11 | #include <linux/jiffies.h> |
12 | #include <linux/timer.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/string.h> | |
8b169fa2 | 15 | #include <linux/module.h> |
1da177e4 | 16 | |
1da177e4 LT |
17 | #include <asm/amigahw.h> |
18 | ||
19 | static unsigned short *snd_data; | |
20 | static const signed char sine_data[] = { | |
21 | 0, 39, 75, 103, 121, 127, 121, 103, 75, 39, | |
22 | 0, -39, -75, -103, -121, -127, -121, -103, -75, -39 | |
23 | }; | |
b9e5e119 | 24 | #define DATA_SIZE ARRAY_SIZE(sine_data) |
1da177e4 | 25 | |
b4290a23 AV |
26 | #define custom amiga_custom |
27 | ||
1da177e4 LT |
28 | /* |
29 | * The minimum period for audio may be modified by the frame buffer | |
30 | * device since it depends on htotal (for OCS/ECS/AGA) | |
31 | */ | |
32 | ||
33 | volatile unsigned short amiga_audio_min_period = 124; /* Default for pre-OCS */ | |
8b169fa2 | 34 | EXPORT_SYMBOL(amiga_audio_min_period); |
1da177e4 LT |
35 | |
36 | #define MAX_PERIOD (65535) | |
37 | ||
38 | ||
39 | /* | |
40 | * Current period (set by dmasound.c) | |
41 | */ | |
42 | ||
43 | unsigned short amiga_audio_period = MAX_PERIOD; | |
8b169fa2 | 44 | EXPORT_SYMBOL(amiga_audio_period); |
1da177e4 LT |
45 | |
46 | static unsigned long clock_constant; | |
47 | ||
48 | void __init amiga_init_sound(void) | |
49 | { | |
50 | static struct resource beep_res = { .name = "Beep" }; | |
51 | ||
52 | snd_data = amiga_chip_alloc_res(sizeof(sine_data), &beep_res); | |
53 | if (!snd_data) { | |
f296401b | 54 | pr_crit("amiga init_sound: failed to allocate chipmem\n"); |
1da177e4 LT |
55 | return; |
56 | } | |
57 | memcpy (snd_data, sine_data, sizeof(sine_data)); | |
58 | ||
59 | /* setup divisor */ | |
60 | clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE; | |
61 | ||
62 | /* without amifb, turn video off and enable high quality sound */ | |
63 | #ifndef CONFIG_FB_AMIGA | |
64 | amifb_video_off(); | |
65 | #endif | |
66 | } | |
67 | ||
68 | static void nosound( unsigned long ignored ); | |
8d06afab | 69 | static DEFINE_TIMER(sound_timer, nosound, 0, 0); |
1da177e4 LT |
70 | |
71 | void amiga_mksound( unsigned int hz, unsigned int ticks ) | |
72 | { | |
73 | unsigned long flags; | |
74 | ||
75 | if (!snd_data) | |
76 | return; | |
77 | ||
78 | local_irq_save(flags); | |
79 | del_timer( &sound_timer ); | |
80 | ||
81 | if (hz > 20 && hz < 32767) { | |
82 | unsigned long period = (clock_constant / hz); | |
83 | ||
84 | if (period < amiga_audio_min_period) | |
85 | period = amiga_audio_min_period; | |
86 | if (period > MAX_PERIOD) | |
87 | period = MAX_PERIOD; | |
88 | ||
89 | /* setup pointer to data, period, length and volume */ | |
90 | custom.aud[2].audlc = snd_data; | |
91 | custom.aud[2].audlen = sizeof(sine_data)/2; | |
92 | custom.aud[2].audper = (unsigned short)period; | |
93 | custom.aud[2].audvol = 32; /* 50% of maxvol */ | |
94 | ||
95 | if (ticks) { | |
96 | sound_timer.expires = jiffies + ticks; | |
97 | add_timer( &sound_timer ); | |
98 | } | |
99 | ||
100 | /* turn on DMA for audio channel 2 */ | |
101 | custom.dmacon = DMAF_SETCLR | DMAF_AUD2; | |
102 | ||
103 | } else | |
104 | nosound( 0 ); | |
105 | ||
106 | local_irq_restore(flags); | |
107 | } | |
108 | ||
109 | ||
110 | static void nosound( unsigned long ignored ) | |
111 | { | |
112 | /* turn off DMA for audio channel 2 */ | |
113 | custom.dmacon = DMAF_AUD2; | |
114 | /* restore period to previous value after beeping */ | |
115 | custom.aud[2].audper = amiga_audio_period; | |
116 | } |