| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 11 | #include <linux/config.h> |
| 12 | #include <linux/jiffies.h> |
| 13 | #include <linux/timer.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/string.h> |
| 16 | |
| 17 | #include <asm/system.h> |
| 18 | #include <asm/amigahw.h> |
| 19 | |
| 20 | static unsigned short *snd_data; |
| 21 | static const signed char sine_data[] = { |
| 22 | 0, 39, 75, 103, 121, 127, 121, 103, 75, 39, |
| 23 | 0, -39, -75, -103, -121, -127, -121, -103, -75, -39 |
| 24 | }; |
| 25 | #define DATA_SIZE (sizeof(sine_data)/sizeof(sine_data[0])) |
| 26 | |
| 27 | /* |
| 28 | * The minimum period for audio may be modified by the frame buffer |
| 29 | * device since it depends on htotal (for OCS/ECS/AGA) |
| 30 | */ |
| 31 | |
| 32 | volatile unsigned short amiga_audio_min_period = 124; /* Default for pre-OCS */ |
| 33 | |
| 34 | #define MAX_PERIOD (65535) |
| 35 | |
| 36 | |
| 37 | /* |
| 38 | * Current period (set by dmasound.c) |
| 39 | */ |
| 40 | |
| 41 | unsigned short amiga_audio_period = MAX_PERIOD; |
| 42 | |
| 43 | static unsigned long clock_constant; |
| 44 | |
| 45 | void __init amiga_init_sound(void) |
| 46 | { |
| 47 | static struct resource beep_res = { .name = "Beep" }; |
| 48 | |
| 49 | snd_data = amiga_chip_alloc_res(sizeof(sine_data), &beep_res); |
| 50 | if (!snd_data) { |
| 51 | printk (KERN_CRIT "amiga init_sound: failed to allocate chipmem\n"); |
| 52 | return; |
| 53 | } |
| 54 | memcpy (snd_data, sine_data, sizeof(sine_data)); |
| 55 | |
| 56 | /* setup divisor */ |
| 57 | clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE; |
| 58 | |
| 59 | /* without amifb, turn video off and enable high quality sound */ |
| 60 | #ifndef CONFIG_FB_AMIGA |
| 61 | amifb_video_off(); |
| 62 | #endif |
| 63 | } |
| 64 | |
| 65 | static void nosound( unsigned long ignored ); |
| 66 | static struct timer_list sound_timer = TIMER_INITIALIZER(nosound, 0, 0); |
| 67 | |
| 68 | void amiga_mksound( unsigned int hz, unsigned int ticks ) |
| 69 | { |
| 70 | unsigned long flags; |
| 71 | |
| 72 | if (!snd_data) |
| 73 | return; |
| 74 | |
| 75 | local_irq_save(flags); |
| 76 | del_timer( &sound_timer ); |
| 77 | |
| 78 | if (hz > 20 && hz < 32767) { |
| 79 | unsigned long period = (clock_constant / hz); |
| 80 | |
| 81 | if (period < amiga_audio_min_period) |
| 82 | period = amiga_audio_min_period; |
| 83 | if (period > MAX_PERIOD) |
| 84 | period = MAX_PERIOD; |
| 85 | |
| 86 | /* setup pointer to data, period, length and volume */ |
| 87 | custom.aud[2].audlc = snd_data; |
| 88 | custom.aud[2].audlen = sizeof(sine_data)/2; |
| 89 | custom.aud[2].audper = (unsigned short)period; |
| 90 | custom.aud[2].audvol = 32; /* 50% of maxvol */ |
| 91 | |
| 92 | if (ticks) { |
| 93 | sound_timer.expires = jiffies + ticks; |
| 94 | add_timer( &sound_timer ); |
| 95 | } |
| 96 | |
| 97 | /* turn on DMA for audio channel 2 */ |
| 98 | custom.dmacon = DMAF_SETCLR | DMAF_AUD2; |
| 99 | |
| 100 | } else |
| 101 | nosound( 0 ); |
| 102 | |
| 103 | local_irq_restore(flags); |
| 104 | } |
| 105 | |
| 106 | |
| 107 | static void nosound( unsigned long ignored ) |
| 108 | { |
| 109 | /* turn off DMA for audio channel 2 */ |
| 110 | custom.dmacon = DMAF_AUD2; |
| 111 | /* restore period to previous value after beeping */ |
| 112 | custom.aud[2].audper = amiga_audio_period; |
| 113 | } |