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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [arch/] [m68k/] [amiga/] [amisound.c] - Blame information for rev 1777

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/*
 * linux/amiga/amisound.c
 *
 * amiga sound driver for 680x0 Linux
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */
 
#include <linux/sched.h>
#include <linux/timer.h>
 
#include <asm/system.h>
#include <asm/amigahw.h>
#include <asm/bootinfo.h>
 
static u_short *snd_data = NULL;
static const signed char sine_data[] = {
        0,  39,  75,  103,  121,  127,  121,  103,  75,  39,
        0, -39, -75, -103, -121, -127, -121, -103, -75, -39
};
#define DATA_SIZE       (sizeof(sine_data)/sizeof(sine_data[0]))
 
    /*
     * The minimum period for audio may be modified by the frame buffer
     * device since it depends on htotal (for OCS/ECS/AGA)
     */
 
volatile u_short amiga_audio_min_period = 124;  /* Default for pre-OCS */
 
#define MAX_PERIOD      (65535)
 
 
    /*
     *  Current period (set by dmasound.c)
     */
 
u_short amiga_audio_period = MAX_PERIOD;
 
static u_long clock_constant;
 
static void init_sound(void)
{
        snd_data = amiga_chip_alloc(sizeof(sine_data));
        if (!snd_data) {
                printk (KERN_CRIT "amiga init_sound: failed to allocate chipmem\n");
                return;
        }
        memcpy (snd_data, sine_data, sizeof(sine_data));
 
        /* setup divisor */
        clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE;
}
 
static void nosound( unsigned long ignored );
static struct timer_list sound_timer = { NULL, NULL, 0, 0, nosound };
 
void amiga_mksound( unsigned int hz, unsigned int ticks )
{
        static int inited = 0;
        unsigned long flags;
 
        if (!inited) {
                init_sound();
                inited = 1;
        }
 
        if (!snd_data)
                return;
 
        save_flags(flags);
        cli();
        del_timer( &sound_timer );
 
        if (hz > 20 && hz < 32767) {
                u_long period = (clock_constant / hz);
 
                if (period < amiga_audio_min_period)
                        period = amiga_audio_min_period;
                if (period > MAX_PERIOD)
                        period = MAX_PERIOD;
 
                /* setup pointer to data, period, length and volume */
                custom.aud[2].audlc = snd_data;
                custom.aud[2].audlen = sizeof(sine_data)/2;
                custom.aud[2].audper = (u_short)period;
                custom.aud[2].audvol = 64; /* maxvol */
 
                if (ticks) {
                        sound_timer.expires = jiffies + ticks;
                        add_timer( &sound_timer );
                }
 
                /* turn on DMA for audio channel 2 */
                custom.dmacon = DMAF_SETCLR | DMAF_AUD2;
 
                restore_flags(flags);
                return;
        } else {
                nosound( 0 );
                restore_flags(flags);
                return;
        }
}
 
 
static void nosound( unsigned long ignored )
{
        /* turn off DMA for audio channel 2 */
        custom.dmacon = DMAF_AUD2;
        /* restore period to previous value after beeping */
        custom.aud[2].audper = amiga_audio_period;
}

Line No.	Rev	Author	Line
1	1623	jcastillo	`/*`
2			`* linux/amiga/amisound.c`
3			`*`
4			`* amiga sound driver for 680x0 Linux`
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/sched.h>`
12			`#include <linux/timer.h>`
13
14			`#include <asm/system.h>`
15			`#include <asm/amigahw.h>`
16			`#include <asm/bootinfo.h>`
17
18			`static u_short *snd_data = NULL;`
19			`static const signed char sine_data[] = {`
20			`0, 39, 75, 103, 121, 127, 121, 103, 75, 39,`
21			`0, -39, -75, -103, -121, -127, -121, -103, -75, -39`
22			`};`
23			`#define DATA_SIZE (sizeof(sine_data)/sizeof(sine_data[0]))`
24
25			`/*`
26			`* The minimum period for audio may be modified by the frame buffer`
27			`* device since it depends on htotal (for OCS/ECS/AGA)`
28			`*/`
29
30			`volatile u_short amiga_audio_min_period = 124; /* Default for pre-OCS */`
31
32			`#define MAX_PERIOD (65535)`
33
34
35			`/*`
36			`* Current period (set by dmasound.c)`
37			`*/`
38
39			`u_short amiga_audio_period = MAX_PERIOD;`
40
41			`static u_long clock_constant;`
42
43			`static void init_sound(void)`
44			`{`
45			`snd_data = amiga_chip_alloc(sizeof(sine_data));`
46			`if (!snd_data) {`
47			`printk (KERN_CRIT "amiga init_sound: failed to allocate chipmem\n");`
48			`return;`
49			`}`
50			`memcpy (snd_data, sine_data, sizeof(sine_data));`
51
52			`/* setup divisor */`
53			`clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE;`
54			`}`
55
56			`static void nosound( unsigned long ignored );`
57			`static struct timer_list sound_timer = { NULL, NULL, 0, 0, nosound };`
58
59			`void amiga_mksound( unsigned int hz, unsigned int ticks )`
60			`{`
61			`static int inited = 0;`
62			`unsigned long flags;`
63
64			`if (!inited) {`
65			`init_sound();`
66			`inited = 1;`
67			`}`
68
69			`if (!snd_data)`
70			`return;`
71
72			`save_flags(flags);`
73			`cli();`
74			`del_timer( &sound_timer );`
75
76			`if (hz > 20 && hz < 32767) {`
77			`u_long period = (clock_constant / hz);`
78
79			`if (period < amiga_audio_min_period)`
80			`period = amiga_audio_min_period;`
81			`if (period > MAX_PERIOD)`
82			`period = MAX_PERIOD;`
83
84			`/* setup pointer to data, period, length and volume */`
85			`custom.aud[2].audlc = snd_data;`
86			`custom.aud[2].audlen = sizeof(sine_data)/2;`
87			`custom.aud[2].audper = (u_short)period;`
88			`custom.aud[2].audvol = 64; /* maxvol */`
89
90			`if (ticks) {`
91			`sound_timer.expires = jiffies + ticks;`
92			`add_timer( &sound_timer );`
93			`}`
94
95			`/* turn on DMA for audio channel 2 */`
96			`custom.dmacon = DMAF_SETCLR \| DMAF_AUD2;`
97
98			`restore_flags(flags);`
99			`return;`
100			`} else {`
101			`nosound( 0 );`
102			`restore_flags(flags);`
103			`return;`
104			`}`
105			`}`
106
107
108			`static void nosound( unsigned long ignored )`
109			`{`
110			`/* turn off DMA for audio channel 2 */`
111			`custom.dmacon = DMAF_AUD2;`
112			`/* restore period to previous value after beeping */`
113			`custom.aud[2].audper = amiga_audio_period;`
114			`}`

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