[sdl_omap.git] / src / audio / dc / aica.c

/* This file is part of the Dreamcast function library.
 * Please see libdream.c for further details.
 *
 * (c)2000 Dan Potter
 * modify BERO
 */
#include "aica.h"

#include <arch/irq.h>
#include <dc/spu.h>

/* #define dc_snd_base ((volatile unsigned char *)0x00800000) */ /* arm side */
#define dc_snd_base ((volatile unsigned char *)0xa0700000) /* dc side */

/* Some convienence macros */
#define	SNDREGADDR(x)	(0xa0700000 + (x))
#define	CHNREGADDR(ch,x)	SNDREGADDR(0x80*(ch)+(x))


#define SNDREG32(x)	(*(volatile unsigned long *)SNDREGADDR(x))
#define SNDREG8(x)	(*(volatile unsigned char *)SNDREGADDR(x))
#define CHNREG32(ch, x) (*(volatile unsigned long *)CHNREGADDR(ch,x))
#define CHNREG8(ch, x)	(*(volatile unsigned long *)CHNREGADDR(ch,x))

#define G2_LOCK(OLD) \
	do { \
		if (!irq_inside_int()) \
			OLD = irq_disable(); \
		/* suspend any G2 DMA here... */ \
		while((*(volatile unsigned int *)0xa05f688c) & 0x20) \
			; \
	} while(0)

#define G2_UNLOCK(OLD) \
	do { \
		/* resume any G2 DMA here... */ \
		if (!irq_inside_int()) \
			irq_restore(OLD); \
	} while(0)


void aica_init() {
	int i, j, old = 0;
	
	/* Initialize AICA channels */	
	G2_LOCK(old);
	SNDREG32(0x2800) = 0x0000;
	
	for (i=0; i<64; i++) {
		for (j=0; j<0x80; j+=4) {
			if ((j&31)==0) g2_fifo_wait();
			CHNREG32(i, j) = 0;
		}
		g2_fifo_wait();
		CHNREG32(i,0) = 0x8000;
		CHNREG32(i,20) = 0x1f;
	}

	SNDREG32(0x2800) = 0x000f;
	g2_fifo_wait();
	G2_UNLOCK(old);
}

/* Translates a volume from linear form to logarithmic form (required by
   the AICA chip */
/* int logs[] = {

0, 40, 50, 58, 63, 68, 73, 77, 80, 83, 86, 89, 92, 94, 97, 99, 101, 103,
105, 107, 109, 111, 112, 114, 116, 117, 119, 120, 122, 123, 125, 126, 127,
129, 130, 131, 133, 134, 135, 136, 137, 139, 140, 141, 142, 143, 144, 145,
146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 156, 157, 158, 159,
160, 161, 162, 162, 163, 164, 165, 166, 166, 167, 168, 169, 170, 170, 171,
172, 172, 173, 174, 175, 175, 176, 177, 177, 178, 179, 180, 180, 181, 182,
182, 183, 183, 184, 185, 185, 186, 187, 187, 188, 188, 189, 190, 190, 191,
191, 192, 193, 193, 194, 194, 195, 196, 196, 197, 197, 198, 198, 199, 199,
200, 201, 201, 202, 202, 203, 203, 204, 204, 205, 205, 206, 206, 207, 207,
208, 208, 209, 209, 210, 210, 211, 211, 212, 212, 213, 213, 214, 214, 215,
215, 216, 216, 217, 217, 217, 218, 218, 219, 219, 220, 220, 221, 221, 222,
222, 222, 223, 223, 224, 224, 225, 225, 225, 226, 226, 227, 227, 228, 228,
228, 229, 229, 230, 230, 230, 231, 231, 232, 232, 232, 233, 233, 234, 234,
234, 235, 235, 236, 236, 236, 237, 237, 238, 238, 238, 239, 239, 240, 240,
240, 241, 241, 241, 242, 242, 243, 243, 243, 244, 244, 244, 245, 245, 245,
246, 246, 247, 247, 247, 248, 248, 248, 249, 249, 249, 250, 250, 250, 251,
251, 251, 252, 252, 252, 253, 253, 253, 254, 254, 254, 255

}; */

const static unsigned char logs[] = {
	0, 15, 22, 27, 31, 35, 39, 42, 45, 47, 50, 52, 55, 57, 59, 61,
	63, 65, 67, 69, 71, 73, 74, 76, 78, 79, 81, 82, 84, 85, 87, 88,
	90, 91, 92, 94, 95, 96, 98, 99, 100, 102, 103, 104, 105, 106,
	108, 109, 110, 111, 112, 113, 114, 116, 117, 118, 119, 120, 121,
	122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,
	135, 136, 137, 138, 138, 139, 140, 141, 142, 143, 144, 145, 146,
	146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 156,
	157, 158, 159, 160, 160, 161, 162, 163, 164, 164, 165, 166, 167,
	167, 168, 169, 170, 170, 171, 172, 173, 173, 174, 175, 176, 176,
	177, 178, 178, 179, 180, 181, 181, 182, 183, 183, 184, 185, 185,
	186, 187, 187, 188, 189, 189, 190, 191, 191, 192, 193, 193, 194,
	195, 195, 196, 197, 197, 198, 199, 199, 200, 200, 201, 202, 202,
	203, 204, 204, 205, 205, 206, 207, 207, 208, 209, 209, 210, 210,
	211, 212, 212, 213, 213, 214, 215, 215, 216, 216, 217, 217, 218,
	219, 219, 220, 220, 221, 221, 222, 223, 223, 224, 224, 225, 225,
	226, 227, 227, 228, 228, 229, 229, 230, 230, 231, 232, 232, 233,
	233, 234, 234, 235, 235, 236, 236, 237, 237, 238, 239, 239, 240,
	240, 241, 241, 242, 242, 243, 243, 244, 244, 245, 245, 246, 246,
	247, 247, 248, 248, 249, 249, 250, 250, 251, 251, 252, 252, 253, 254, 255
};

/* For the moment this is going to have to suffice, until we really
   figure out what these mean. */
#define AICA_PAN(x) ((x)==0x80?(0):((x)<0x80?(0x1f):(0x0f)))
#define AICA_VOL(x) (0xff - logs[128 + (((x) & 0xff) / 2)])
//#define AICA_VOL(x) (0xff - logs[x&255])

static inline unsigned  AICA_FREQ(unsigned freq)	{
	unsigned long freq_lo, freq_base = 5644800;
	int freq_hi = 7;

	/* Need to convert frequency to floating point format
	   (freq_hi is exponent, freq_lo is mantissa)
	   Formula is ferq = 44100*2^freq_hi*(1+freq_lo/1024) */
	while (freq < freq_base && freq_hi > -8) {
		freq_base >>= 1;
		--freq_hi;
	}
	while (freq < freq_base && freq_hi > -8) {
		freq_base >>= 1;
		freq_hi--;
	}
	freq_lo = (freq<<10) / freq_base;
	return (freq_hi << 11) | (freq_lo & 1023);
}

/* Sets up a sound channel completely. This is generally good if you want
   a quick and dirty way to play notes. If you want a more comprehensive
   set of routines (more like PC wavetable cards) see below.
   
   ch is the channel to play on (0 - 63)
   smpptr is the pointer to the sound data; if you're running off the
     SH4, then this ought to be (ptr - 0xa0800000); otherwise it's just
     ptr. Basically, it's an offset into sound ram.
   mode is one of the mode constants (16 bit, 8 bit, ADPCM)
   nsamp is the number of samples to play (not number of bytes!)
   freq is the sampling rate of the sound
   vol is the volume, 0 to 0xff (0xff is louder)
   pan is a panning constant -- 0 is left, 128 is center, 255 is right.

   This routine (and the similar ones) owe a lot to Marcus' sound example -- 
   I hadn't gotten quite this far into dissecting the individual regs yet. */
void aica_play(int ch,int mode,unsigned long smpptr,int loopst,int loopend,int freq,int vol,int pan,int loopflag) {
/*	int i;
*/
	int val;
	int old = 0;

	/* Stop the channel (if it's already playing) */
	aica_stop(ch);
	/* doesn't seem to be needed, but it's here just in case */
/*
	for (i=0; i<256; i++) {
		asm("nop");
		asm("nop");
		asm("nop");
		asm("nop");
	}
*/
	G2_LOCK(old);
	/* Envelope setup. The first of these is the loop point,
	   e.g., where the sample starts over when it loops. The second
	   is the loop end. This is the full length of the sample when
	   you are not looping, or the loop end point when you are (though
	   storing more than that is a waste of memory if you're not doing
	   volume enveloping). */
	CHNREG32(ch, 8) = loopst & 0xffff;
	CHNREG32(ch, 12) = loopend & 0xffff;
	
	/* Write resulting values */
	CHNREG32(ch, 24) = AICA_FREQ(freq);
	
	/* Set volume, pan, and some other things that we don't know what
	   they do =) */
	CHNREG32(ch, 36) = AICA_PAN(pan) | (0xf<<8);
	/* Convert the incoming volume and pan into hardware values */
	/* Vol starts at zero so we can ramp */
	vol = AICA_VOL(vol);
	CHNREG32(ch, 40) = 0x24 | (vol<<8);
	/* Convert the incoming volume and pan into hardware values */
	/* Vol starts at zero so we can ramp */

	/* If we supported volume envelopes (which we don't yet) then
	   this value would set that up. The top 4 bits determine the
	   envelope speed. f is the fastest, 1 is the slowest, and 0
	   seems to be an invalid value and does weird things). The
	   default (below) sets it into normal mode (play and terminate/loop).
	CHNREG32(ch, 16) = 0xf010;
	*/
	CHNREG32(ch, 16) = 0x1f;	/* No volume envelope */
	
	
	/* Set sample format, buffer address, and looping control. If
	   0x0200 mask is set on reg 0, the sample loops infinitely. If
	   it's not set, the sample plays once and terminates. We'll
	   also set the bits to start playback here. */
	CHNREG32(ch, 4) = smpptr & 0xffff;
	val = 0xc000 | 0x0000 | (mode<<7) | (smpptr >> 16);
	if (loopflag) val|=0x200;
	
	CHNREG32(ch, 0) = val;
	
	G2_UNLOCK(old);

	/* Enable playback */
	/* CHNREG32(ch, 0) |= 0xc000; */
	g2_fifo_wait();

#if 0
	for (i=0xff; i>=vol; i--) {
		if ((i&7)==0) g2_fifo_wait();
		CHNREG32(ch, 40) =  0x24 | (i<<8);;
	}

	g2_fifo_wait();
#endif
}

/* Stop the sound on a given channel */
void aica_stop(int ch) {
	g2_write_32(CHNREGADDR(ch, 0),(g2_read_32(CHNREGADDR(ch, 0)) & ~0x4000) | 0x8000);
	g2_fifo_wait();
}


/* The rest of these routines can change the channel in mid-stride so you
   can do things like vibrato and panning effects. */
   
/* Set channel volume */
void aica_vol(int ch,int vol) {
//	g2_write_8(CHNREGADDR(ch, 41),AICA_VOL(vol));
	g2_write_32(CHNREGADDR(ch, 40),(g2_read_32(CHNREGADDR(ch, 40))&0xffff00ff)|(AICA_VOL(vol)<<8) );
	g2_fifo_wait();
}

/* Set channel pan */
void aica_pan(int ch,int pan) {
//	g2_write_8(CHNREGADDR(ch, 36),AICA_PAN(pan));
	g2_write_32(CHNREGADDR(ch, 36),(g2_read_32(CHNREGADDR(ch, 36))&0xffffff00)|(AICA_PAN(pan)) );
	g2_fifo_wait();
}

/* Set channel frequency */
void aica_freq(int ch,int freq) {
	g2_write_32(CHNREGADDR(ch, 24),AICA_FREQ(freq));
	g2_fifo_wait();
}

/* Get channel position */
int aica_get_pos(int ch) {
#if 1
	/* Observe channel ch */
	g2_write_32(SNDREGADDR(0x280c),(g2_read_32(SNDREGADDR(0x280c))&0xffff00ff) | (ch<<8));
	g2_fifo_wait();
	/* Update position counters */
	return g2_read_32(SNDREGADDR(0x2814)) & 0xffff;
#else
	/* Observe channel ch */
	g2_write_8(SNDREGADDR(0x280d),ch);
	/* Update position counters */
	return g2_read_32(SNDREGADDR(0x2814)) & 0xffff;
#endif
}
Commit	Line	Data
e14743d1	1	/* This file is part of the Dreamcast function library.
	2	* Please see libdream.c for further details.
	3	*
	4	* (c)2000 Dan Potter
	5	* modify BERO
	6	*/
	7	#include "aica.h"
	8
	9	#include <arch/irq.h>
	10	#include <dc/spu.h>
	11
	12	/* #define dc_snd_base ((volatile unsigned char )0x00800000) / /* arm side */
	13	#define dc_snd_base ((volatile unsigned char )0xa0700000) / dc side */
	14
	15	/* Some convienence macros */
	16	#define SNDREGADDR(x) (0xa0700000 + (x))
	17	#define CHNREGADDR(ch,x) SNDREGADDR(0x80*(ch)+(x))
	18
	19
	20	#define SNDREG32(x) ((volatile unsigned long )SNDREGADDR(x))
	21	#define SNDREG8(x) ((volatile unsigned char )SNDREGADDR(x))
	22	#define CHNREG32(ch, x) ((volatile unsigned long )CHNREGADDR(ch,x))
	23	#define CHNREG8(ch, x) ((volatile unsigned long )CHNREGADDR(ch,x))
	24
	25	#define G2_LOCK(OLD) \
	26	do { \
	27	if (!irq_inside_int()) \
	28	OLD = irq_disable(); \
	29	/* suspend any G2 DMA here... */ \
	30	while(((volatile unsigned int )0xa05f688c) & 0x20) \
	31	; \
	32	} while(0)
	33
	34	#define G2_UNLOCK(OLD) \
	35	do { \
	36	/* resume any G2 DMA here... */ \
	37	if (!irq_inside_int()) \
	38	irq_restore(OLD); \
	39	} while(0)
	40
	41
	42	void aica_init() {
	43	int i, j, old = 0;
	44
	45	/* Initialize AICA channels */
	46	G2_LOCK(old);
	47	SNDREG32(0x2800) = 0x0000;
	48
	49	for (i=0; i<64; i++) {
	50	for (j=0; j<0x80; j+=4) {
	51	if ((j&31)==0) g2_fifo_wait();
	52	CHNREG32(i, j) = 0;
	53	}
	54	g2_fifo_wait();
	55	CHNREG32(i,0) = 0x8000;
	56	CHNREG32(i,20) = 0x1f;
	57	}
	58
	59	SNDREG32(0x2800) = 0x000f;
	60	g2_fifo_wait();
	61	G2_UNLOCK(old);
	62	}
	63
	64	/* Translates a volume from linear form to logarithmic form (required by
65	the AICA chip */
66	/* int logs[] = {
67
68	0, 40, 50, 58, 63, 68, 73, 77, 80, 83, 86, 89, 92, 94, 97, 99, 101, 103,
69	105, 107, 109, 111, 112, 114, 116, 117, 119, 120, 122, 123, 125, 126, 127,
70	129, 130, 131, 133, 134, 135, 136, 137, 139, 140, 141, 142, 143, 144, 145,
71	146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 156, 157, 158, 159,
72	160, 161, 162, 162, 163, 164, 165, 166, 166, 167, 168, 169, 170, 170, 171,
73	172, 172, 173, 174, 175, 175, 176, 177, 177, 178, 179, 180, 180, 181, 182,
74	182, 183, 183, 184, 185, 185, 186, 187, 187, 188, 188, 189, 190, 190, 191,
75	191, 192, 193, 193, 194, 194, 195, 196, 196, 197, 197, 198, 198, 199, 199,
76	200, 201, 201, 202, 202, 203, 203, 204, 204, 205, 205, 206, 206, 207, 207,
77	208, 208, 209, 209, 210, 210, 211, 211, 212, 212, 213, 213, 214, 214, 215,
78	215, 216, 216, 217, 217, 217, 218, 218, 219, 219, 220, 220, 221, 221, 222,
79	222, 222, 223, 223, 224, 224, 225, 225, 225, 226, 226, 227, 227, 228, 228,
80	228, 229, 229, 230, 230, 230, 231, 231, 232, 232, 232, 233, 233, 234, 234,
81	234, 235, 235, 236, 236, 236, 237, 237, 238, 238, 238, 239, 239, 240, 240,
82	240, 241, 241, 241, 242, 242, 243, 243, 243, 244, 244, 244, 245, 245, 245,
83	246, 246, 247, 247, 247, 248, 248, 248, 249, 249, 249, 250, 250, 250, 251,
84	251, 251, 252, 252, 252, 253, 253, 253, 254, 254, 254, 255
85
86	}; */
87
88	const static unsigned char logs[] = {
89	0, 15, 22, 27, 31, 35, 39, 42, 45, 47, 50, 52, 55, 57, 59, 61,
90	63, 65, 67, 69, 71, 73, 74, 76, 78, 79, 81, 82, 84, 85, 87, 88,
91	90, 91, 92, 94, 95, 96, 98, 99, 100, 102, 103, 104, 105, 106,
92	108, 109, 110, 111, 112, 113, 114, 116, 117, 118, 119, 120, 121,
93	122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,
94	135, 136, 137, 138, 138, 139, 140, 141, 142, 143, 144, 145, 146,
95	146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 156,
96	157, 158, 159, 160, 160, 161, 162, 163, 164, 164, 165, 166, 167,
97	167, 168, 169, 170, 170, 171, 172, 173, 173, 174, 175, 176, 176,
98	177, 178, 178, 179, 180, 181, 181, 182, 183, 183, 184, 185, 185,
99	186, 187, 187, 188, 189, 189, 190, 191, 191, 192, 193, 193, 194,
100	195, 195, 196, 197, 197, 198, 199, 199, 200, 200, 201, 202, 202,
101	203, 204, 204, 205, 205, 206, 207, 207, 208, 209, 209, 210, 210,
102	211, 212, 212, 213, 213, 214, 215, 215, 216, 216, 217, 217, 218,
103	219, 219, 220, 220, 221, 221, 222, 223, 223, 224, 224, 225, 225,
104	226, 227, 227, 228, 228, 229, 229, 230, 230, 231, 232, 232, 233,
105	233, 234, 234, 235, 235, 236, 236, 237, 237, 238, 239, 239, 240,
106	240, 241, 241, 242, 242, 243, 243, 244, 244, 245, 245, 246, 246,
107	247, 247, 248, 248, 249, 249, 250, 250, 251, 251, 252, 252, 253, 254, 255
108	};
109
110	/* For the moment this is going to have to suffice, until we really
111	figure out what these mean. */
112	#define AICA_PAN(x) ((x)==0x80?(0):((x)<0x80?(0x1f):(0x0f)))
113	#define AICA_VOL(x) (0xff - logs[128 + (((x) & 0xff) / 2)])
114	//#define AICA_VOL(x) (0xff - logs[x&255])
115
116	static inline unsigned AICA_FREQ(unsigned freq) {
117	unsigned long freq_lo, freq_base = 5644800;
118	int freq_hi = 7;
119
120	/* Need to convert frequency to floating point format
121	(freq_hi is exponent, freq_lo is mantissa)
122	Formula is ferq = 441002^freq_hi(1+freq_lo/1024) */
123	while (freq < freq_base && freq_hi > -8) {
124	freq_base >>= 1;
125	--freq_hi;
126	}
127	while (freq < freq_base && freq_hi > -8) {
128	freq_base >>= 1;
129	freq_hi--;
130	}
131	freq_lo = (freq<<10) / freq_base;
132	return (freq_hi << 11) \| (freq_lo & 1023);
133	}
134
135	/* Sets up a sound channel completely. This is generally good if you want
136	a quick and dirty way to play notes. If you want a more comprehensive
137	set of routines (more like PC wavetable cards) see below.
138
139	ch is the channel to play on (0 - 63)
140	smpptr is the pointer to the sound data; if you're running off the
141	SH4, then this ought to be (ptr - 0xa0800000); otherwise it's just
142	ptr. Basically, it's an offset into sound ram.
143	mode is one of the mode constants (16 bit, 8 bit, ADPCM)
144	nsamp is the number of samples to play (not number of bytes!)
145	freq is the sampling rate of the sound
146	vol is the volume, 0 to 0xff (0xff is louder)
147	pan is a panning constant -- 0 is left, 128 is center, 255 is right.
148
149	This routine (and the similar ones) owe a lot to Marcus' sound example --
150	I hadn't gotten quite this far into dissecting the individual regs yet. */
151	void aica_play(int ch,int mode,unsigned long smpptr,int loopst,int loopend,int freq,int vol,int pan,int loopflag) {
152	/* int i;
153	*/
154	int val;
155	int old = 0;
156
157	/* Stop the channel (if it's already playing) */
158	aica_stop(ch);
159	/* doesn't seem to be needed, but it's here just in case */
160	/*
161	for (i=0; i<256; i++) {
162	asm("nop");
163	asm("nop");
164	asm("nop");
165	asm("nop");
166	}
167	*/
168	G2_LOCK(old);
169	/* Envelope setup. The first of these is the loop point,
170	e.g., where the sample starts over when it loops. The second
171	is the loop end. This is the full length of the sample when
172	you are not looping, or the loop end point when you are (though
173	storing more than that is a waste of memory if you're not doing
174	volume enveloping). */
175	CHNREG32(ch, 8) = loopst & 0xffff;
176	CHNREG32(ch, 12) = loopend & 0xffff;
177
178	/* Write resulting values */
179	CHNREG32(ch, 24) = AICA_FREQ(freq);
180
181	/* Set volume, pan, and some other things that we don't know what
182	they do =) */
183	CHNREG32(ch, 36) = AICA_PAN(pan) \| (0xf<<8);
184	/* Convert the incoming volume and pan into hardware values */
185	/* Vol starts at zero so we can ramp */
186	vol = AICA_VOL(vol);
187	CHNREG32(ch, 40) = 0x24 \| (vol<<8);
188	/* Convert the incoming volume and pan into hardware values */
189	/* Vol starts at zero so we can ramp */
190
191	/* If we supported volume envelopes (which we don't yet) then
192	this value would set that up. The top 4 bits determine the
193	envelope speed. f is the fastest, 1 is the slowest, and 0
194	seems to be an invalid value and does weird things). The
195	default (below) sets it into normal mode (play and terminate/loop).
196	CHNREG32(ch, 16) = 0xf010;
197	*/
198	CHNREG32(ch, 16) = 0x1f; /* No volume envelope */
199
200
201	/* Set sample format, buffer address, and looping control. If
202	0x0200 mask is set on reg 0, the sample loops infinitely. If
203	it's not set, the sample plays once and terminates. We'll
204	also set the bits to start playback here. */
205	CHNREG32(ch, 4) = smpptr & 0xffff;
206	val = 0xc000 \| 0x0000 \| (mode<<7) \| (smpptr >> 16);
207	if (loopflag) val\|=0x200;
208
209	CHNREG32(ch, 0) = val;
210
211	G2_UNLOCK(old);
212
213	/* Enable playback */
214	/* CHNREG32(ch, 0) \|= 0xc000; */
215	g2_fifo_wait();
216
217	#if 0
218	for (i=0xff; i>=vol; i--) {
219	if ((i&7)==0) g2_fifo_wait();
220	CHNREG32(ch, 40) = 0x24 \| (i<<8);;
221	}
222
223	g2_fifo_wait();
224	#endif
225	}
226
227	/* Stop the sound on a given channel */
228	void aica_stop(int ch) {
229	g2_write_32(CHNREGADDR(ch, 0),(g2_read_32(CHNREGADDR(ch, 0)) & ~0x4000) \| 0x8000);
230	g2_fifo_wait();
231	}
232
233
234	/* The rest of these routines can change the channel in mid-stride so you
235	can do things like vibrato and panning effects. */
236
237	/* Set channel volume */
238	void aica_vol(int ch,int vol) {
239	// g2_write_8(CHNREGADDR(ch, 41),AICA_VOL(vol));
240	g2_write_32(CHNREGADDR(ch, 40),(g2_read_32(CHNREGADDR(ch, 40))&0xffff00ff)\|(AICA_VOL(vol)<<8) );
241	g2_fifo_wait();
242	}
243
244	/* Set channel pan */
245	void aica_pan(int ch,int pan) {
246	// g2_write_8(CHNREGADDR(ch, 36),AICA_PAN(pan));
247	g2_write_32(CHNREGADDR(ch, 36),(g2_read_32(CHNREGADDR(ch, 36))&0xffffff00)\|(AICA_PAN(pan)) );
248	g2_fifo_wait();
249	}
250
251	/* Set channel frequency */
252	void aica_freq(int ch,int freq) {
253	g2_write_32(CHNREGADDR(ch, 24),AICA_FREQ(freq));
254	g2_fifo_wait();
255	}
256
257	/* Get channel position */
258	int aica_get_pos(int ch) {
259	#if 1
260	/* Observe channel ch */
261	g2_write_32(SNDREGADDR(0x280c),(g2_read_32(SNDREGADDR(0x280c))&0xffff00ff) \| (ch<<8));
262	g2_fifo_wait();
263	/* Update position counters */
264	return g2_read_32(SNDREGADDR(0x2814)) & 0xffff;
265	#else
266	/* Observe channel ch */
267	g2_write_8(SNDREGADDR(0x280d),ch);
268	/* Update position counters */
269	return g2_read_32(SNDREGADDR(0x2814)) & 0xffff;
270	#endif
271	}