rockbox/firmware/target/arm/pcm-pp.c

765 lines
23 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Michael Sevakis
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdlib.h>
#include "system.h"
#include "kernel.h"
#include "logf.h"
#include "audio.h"
#include "sound.h"
#include "pcm.h"
#include "pcm_sampr.h"
/** DMA **/
#ifdef CPU_PP502x
/* 16-bit, L-R packed into 32 bits with left in the least significant halfword */
#define SAMPLE_SIZE 16
/* DMA Requests from IIS, Memory to peripheral, single transfer,
wait for DMA request, interrupt on complete */
#define DMA_PLAY_CONFIG ((DMA_REQ_IIS << DMA_CMD_REQ_ID_POS) | \
DMA_CMD_RAM_TO_PER | DMA_CMD_SINGLE | \
DMA_CMD_WAIT_REQ | DMA_CMD_INTR)
/* DMA status cannot be viewed from outside code in control because that can
* clear the interrupt from outside the handler and prevent the handler from
* from being called. Split up transfers to a reasonable size that is good as
* a timer, obtaining a keyclick position and peaking yet still keeps the
* FIQ count low.
*/
#define MAX_DMA_CHUNK_SIZE (pcm_curr_sampr >> 6) /* ~1/256 seconds */
#else
/* 32-bit, one left 32-bit sample followed by one right 32-bit sample */
#define SAMPLE_SIZE 32
#endif
struct dma_data
{
/* NOTE: The order of size and p is important if you use assembler
optimised fiq handler, so don't change it. */
union
{
unsigned long addr;
uint32_t *p16; /* For packed 16-16 stereo pairs */
uint16_t *p32; /* For individual samples converted to 32-bit */
};
size_t size;
#if NUM_CORES > 1
unsigned core;
#endif
int locked;
int state;
};
extern void *fiq_function;
/* Dispatch to the proper handler and leave the main vector table alone */
void fiq_handler(void) ICODE_ATTR __attribute__((naked));
void fiq_handler(void)
{
asm volatile (
"ldr pc, [pc, #-4] \n"
"fiq_function: \n"
".word 0 \n"
);
}
#ifdef HAVE_PCM_DMA_ADDRESS
void * pcm_dma_addr(void *addr)
{
if (addr != NULL && (unsigned long)addr < UNCACHED_BASE_ADDR)
addr = UNCACHED_ADDR(addr);
return addr;
}
#endif
/* TODO: Get simultaneous recording and playback to work. Just needs some tweaking */
/****************************************************************************
** Playback DMA transfer
**/
static struct dma_data dma_play_data IBSS_ATTR =
{
/* Initialize to a locked, stopped state */
{ .addr = 0 },
.size = 0,
#if NUM_CORES > 1
.core = 0x00,
#endif
.locked = 0,
.state = 0
};
void pcm_dma_apply_settings(void)
{
audiohw_set_frequency(pcm_fsel);
}
#if defined(CPU_PP502x)
/* NOTE: direct stack use forbidden by GCC stack handling bug for FIQ */
void ICODE_ATTR __attribute__((interrupt("FIQ"))) fiq_playback(void)
{
register pcm_more_callback_type get_more;
register size_t size;
DMA0_STATUS; /* Clear any pending interrupt */
size = (DMA0_CMD & 0xffff) + 4; /* Get size of trasfer that caused this
interrupt */
dma_play_data.addr += size;
dma_play_data.size -= size;
while (1)
{
if (dma_play_data.size > 0) {
size = MAX_DMA_CHUNK_SIZE;
/* Not at least MAX_DMA_CHUNK_SIZE left or there would be less
* than a FIFO's worth of data after this transfer? */
if (size + 16*4 > dma_play_data.size)
size = dma_play_data.size;
/* Set the new DMA values and activate channel */
DMA0_RAM_ADDR = dma_play_data.addr;
DMA0_CMD = DMA_PLAY_CONFIG | (size - 4) | DMA_CMD_START;
return;
}
/* Buffer empty. Try to get more. */
get_more = pcm_callback_for_more;
if (get_more) {
get_more((unsigned char **)&dma_play_data.addr, &dma_play_data.size);
dma_play_data.addr = (dma_play_data.addr + 2) & ~3;
dma_play_data.size &= ~3;
}
if (dma_play_data.size == 0) {
break;
}
if (dma_play_data.addr < UNCACHED_BASE_ADDR) {
/* Flush any pending cache writes */
dma_play_data.addr = UNCACHED_ADDR(dma_play_data.addr);
cpucache_flush();
}
}
/* Callback missing or no more DMA to do */
pcm_play_dma_stop();
pcm_play_dma_stopped_callback();
}
#else
/* ASM optimised FIQ handler. Checks for the minimum allowed loop cycles by
* evalutation of free IISFIFO-slots against available source buffer words.
* Through this it is possible to move the check for IIS_TX_FREE_COUNT outside
* the loop and do some further optimization. Right after the loops (source
* buffer -> IISFIFO) are done we need to check whether we have to exit FIQ
* handler (this must be done, if all free FIFO slots were filled) or we will
* have to get some new source data. Important information kept from former
* ASM implementation (not used anymore): GCC fails to make use of the fact
* that FIQ mode has registers r8-r14 banked, and so does not need to be saved.
* This routine uses only these registers, and so will never touch the stack
* unless it actually needs to do so when calling pcm_callback_for_more.
* C version is still included below for reference and testing.
*/
#if 1
void fiq_playback(void) ICODE_ATTR __attribute__((naked));
void fiq_playback(void)
{
/* r10 contains IISCONFIG address (set in crt0.S to minimise code in actual
* FIQ handler. r11 contains address of p (also set in crt0.S). Most other
* addresses we need are generated by using offsets with these two.
* r10 + 0x40 is IISFIFO_WR, and r10 + 0x0c is IISFIFO_CFG.
* r8 and r9 contains local copies of p and size respectively.
* r0-r3 and r12 is a working register.
*/
asm volatile (
"stmfd sp!, { r0-r3, lr } \n" /* stack scratch regs and lr */
#if CONFIG_CPU == PP5002
"ldr r12, =0xcf001040 \n" /* Some magic from iPodLinux */
"ldr r12, [r12] \n"
#endif
"ldmia r11, { r8-r9 } \n" /* r8 = p, r9 = size */
"cmp r9, #0 \n" /* is size 0? */
"beq .more_data \n" /* if so, ask pcmbuf for more data */
#if SAMPLE_SIZE == 16
".check_fifo: \n"
"ldr r0, [r10, %[cfg]] \n" /* read IISFIFO_CFG to check FIFO status */
"and r0, r0, %[mask] \n" /* r0 = IIS_TX_FREE_COUNT << 16 (PP502x) */
"mov r1, r0, lsr #16 \n" /* number of free FIFO slots */
"cmp r1, r9, lsr #2 \n" /* number of words from source */
"movgt r1, r9, lsr #2 \n" /* r1 = amount of allowed loops */
"sub r9, r9, r1, lsl #2 \n" /* r1 words will be written in following loop */
"subs r1, r1, #2 \n"
".fifo_loop_2: \n"
"ldmgeia r8!, {r2, r12} \n" /* load four samples */
"strge r2 , [r10, %[wr]] \n" /* write sample 0-1 to IISFIFO_WR */
"strge r12, [r10, %[wr]] \n" /* write sample 2-3 to IISFIFO_WR */
"subges r1, r1, #2 \n" /* one more loop? */
"bge .fifo_loop_2 \n" /* yes, continue */
"tst r1, #1 \n" /* two samples (one word) left? */
"ldrne r12, [r8], #4 \n" /* load two samples */
"strne r12, [r10, %[wr]] \n" /* write sample 0-1 to IISFIFO_WR */
"cmp r9, #0 \n" /* either FIFO is full or source buffer is empty */
"bgt .exit \n" /* if source buffer is not empty, FIFO must be full */
#elif SAMPLE_SIZE == 32
".check_fifo: \n"
"ldr r0, [r10, %[cfg]] \n" /* read IISFIFO_CFG to check FIFO status */
"and r0, r0, %[mask] \n" /* r0 = IIS_TX_FREE_COUNT << 23 (PP5002) */
"movs r1, r0, lsr #24 \n" /* number of free pairs of FIFO slots */
"beq .exit \n" /* no complete pair? -> exit */
"cmp r1, r9, lsr #2 \n" /* number of words from source */
"movgt r1, r9, lsr #2 \n" /* r1 = amount of allowed loops */
"sub r9, r9, r1, lsl #2 \n" /* r1 words will be written in following loop */
".fifo_loop: \n"
"ldr r12, [r8], #4 \n" /* load two samples */
"mov r2 , r12, lsl #16 \n" /* put left sample at the top bits */
"str r2 , [r10, %[wr]] \n" /* write top sample to IISFIFO_WR */
"str r12, [r10, %[wr]] \n" /* write low sample to IISFIFO_WR*/
"subs r1, r1, #1 \n" /* one more loop? */
"bgt .fifo_loop \n" /* yes, continue */
"cmp r9, #0 \n" /* either FIFO is full or source buffer is empty */
"bgt .exit \n" /* if source buffer is not empty, FIFO must be full */
#endif
".more_data: \n"
"ldr r2, =pcm_callback_for_more \n"
"ldr r2, [r2] \n" /* get callback address */
"cmp r2, #0 \n" /* check for null pointer */
"beq .stop \n" /* callback removed, stop */
"stmia r11, { r8-r9 } \n" /* save internal copies of variables back */
"mov r0, r11 \n" /* r0 = &p */
"add r1, r11, #4 \n" /* r1 = &size */
"mov lr, pc \n" /* call pcm_callback_for_more */
"bx r2 \n"
"ldmia r11, { r8-r9 } \n" /* reload p and size */
"cmp r9, #0 \n" /* did we actually get more data? */
"bne .check_fifo \n"
".stop: \n" /* call termination routines */
"ldr r12, =pcm_play_dma_stop \n"
"mov lr, pc \n"
"bx r12 \n"
"ldr r12, =pcm_play_dma_stopped_callback \n"
"mov lr, pc \n"
"bx r12 \n"
".exit: \n" /* (r8=0 if stopping, look above) */
"stmia r11, { r8-r9 } \n" /* save p and size */
"ldmfd sp!, { r0-r3, lr } \n"
"subs pc, lr, #4 \n" /* FIQ specific return sequence */
".ltorg \n"
: /* These must only be integers! No regs */
: [mask]"i"(IIS_TX_FREE_MASK),
[cfg]"i"((int)&IISFIFO_CFG - (int)&IISCONFIG),
[wr]"i"((int)&IISFIFO_WR - (int)&IISCONFIG)
);
}
#else /* C version for reference */
void fiq_playback(void) __attribute__((interrupt ("FIQ"))) ICODE_ATTR;
/* NOTE: direct stack use forbidden by GCC stack handling bug for FIQ */
void fiq_playback(void)
{
register pcm_more_callback_type get_more;
#if CONFIG_CPU == PP5002
inl(0xcf001040);
#endif
do {
while (dma_play_data.size > 0) {
if (IIS_TX_FREE_COUNT < 2) {
return;
}
#if SAMPLE_SIZE == 16
IISFIFO_WR = *dma_play_data.p16++;
#elif SAMPLE_SIZE == 32
IISFIFO_WR = *dma_play_data.p32++ << 16;
IISFIFO_WR = *dma_play_data.p32++ << 16;
#endif
dma_play_data.size -= 4;
}
/* p is empty, get some more data */
get_more = pcm_callback_for_more;
if (get_more) {
get_more((unsigned char**)&dma_play_data.addr,
&dma_play_data.size);
}
} while (dma_play_data.size);
/* No more data, so disable the FIFO/interrupt */
pcm_play_dma_stop();
pcm_play_dma_stopped_callback();
}
#endif /* ASM / C selection */
#endif /* CPU_PP502x */
/* For the locks, FIQ must be disabled because the handler manipulates
IISCONFIG and the operation is not atomic - dual core support
will require other measures */
void pcm_play_lock(void)
{
int status = disable_fiq_save();
if (++dma_play_data.locked == 1) {
#ifdef CPU_PP502x
CPU_INT_DIS = DMA_MASK;
#else
IIS_IRQTX_REG &= ~IIS_IRQTX;
#endif
}
restore_fiq(status);
}
void pcm_play_unlock(void)
{
int status = disable_fiq_save();
if (--dma_play_data.locked == 0 && dma_play_data.state != 0) {
#ifdef CPU_PP502x
CPU_INT_EN = DMA_MASK;
#else
IIS_IRQTX_REG |= IIS_IRQTX;
#endif
}
restore_fiq(status);
}
static void play_start_pcm(void)
{
fiq_function = fiq_playback;
#ifdef CPU_PP502x
/* Not at least MAX_DMA_CHUNK_SIZE left or there would be less than a
* FIFO's worth of data after this transfer? */
size_t size = MAX_DMA_CHUNK_SIZE;
if (size + 16*4 > dma_play_data.size)
size = dma_play_data.size;
DMA0_RAM_ADDR = dma_play_data.addr;
DMA0_CMD = DMA_PLAY_CONFIG | (size - 4) | DMA_CMD_START;
dma_play_data.state = 1;
#else
IISCONFIG &= ~IIS_TXFIFOEN; /* Stop transmitting */
/* Fill the FIFO or start when data is used up */
while (1) {
if (IIS_TX_FREE_COUNT < 2 || dma_play_data.size == 0) {
IISCONFIG |= IIS_TXFIFOEN; /* Start transmitting */
dma_play_data.state = 1;
return;
}
#if SAMPLE_SIZE == 16
IISFIFO_WR = *dma_play_data.p16++;
#elif SAMPLE_SIZE == 32
IISFIFO_WR = *dma_play_data.p32++ << 16;
IISFIFO_WR = *dma_play_data.p32++ << 16;
#endif
dma_play_data.size -= 4;
}
#endif
}
static void play_stop_pcm(void)
{
#ifdef CPU_PP502x
unsigned long status = DMA0_STATUS; /* Snapshot- resume from this point */
unsigned long cmd = DMA0_CMD;
size_t size = 0;
/* Stop transfer */
DMA0_CMD = cmd & ~(DMA_CMD_START | DMA_CMD_INTR);
/* Wait for not busy + clear int */
while (DMA0_STATUS & (DMA_STATUS_BUSY | DMA_STATUS_INTR));
if (status & DMA_STATUS_BUSY) {
/* Transfer was interrupted - leave what's left */
size = (cmd & 0xfffc) - (status & 0xfffc);
}
else if (status & DMA_STATUS_INTR) {
/* Transfer was finished - DMA0_STATUS will have been reloaded
* automatically with size in DMA0_CMD. Setup to restart on next
* segment. */
size = (cmd & 0xfffc) + 4;
}
/* else not an active state - size = 0 */
dma_play_data.addr += size;
dma_play_data.size -= size;
if (dma_play_data.size == 0)
dma_play_data.addr = 0; /* Entire buffer has completed. */
#else
/* Disable TX interrupt */
IIS_IRQTX_REG &= ~IIS_IRQTX;
#endif
/* Wait for FIFO to empty */
while (!IIS_TX_IS_EMPTY);
dma_play_data.state = 0;
}
void pcm_play_dma_start(const void *addr, size_t size)
{
addr = (void *)(((long)addr + 2) & ~3);
size &= ~3;
#if NUM_CORES > 1
/* This will become more important later - and different ! */
dma_play_data.core = processor_id(); /* save initiating core */
#endif
pcm_play_dma_stop();
if (size == 0)
return;
#ifdef CPU_PP502x
if ((unsigned long)addr < UNCACHED_BASE_ADDR) {
/* Flush any pending cache writes */
addr = UNCACHED_ADDR(addr);
cpucache_flush();
}
dma_play_data.addr = (unsigned long)addr;
dma_play_data.size = size;
DMA0_PER_ADDR = (unsigned long)&IISFIFO_WR;
DMA0_FLAGS = DMA_FLAGS_UNK26;
DMA0_INCR = DMA_INCR_RANGE_FIXED | DMA_INCR_WIDTH_32BIT;
#endif
play_start_pcm();
}
/* Stops the DMA transfer and interrupt */
void pcm_play_dma_stop(void)
{
play_stop_pcm();
dma_play_data.addr = 0;
dma_play_data.size = 0;
#if NUM_CORES > 1
dma_play_data.core = 0; /* no core in control */
#endif
}
void pcm_play_dma_pause(bool pause)
{
if (pause) {
play_stop_pcm();
} else {
play_start_pcm();
}
}
size_t pcm_get_bytes_waiting(void)
{
return dma_play_data.size & ~3;
}
void pcm_play_dma_init(void)
{
/* Initialize default register values. */
audiohw_init();
#ifdef CPU_PP502x
/* Enable DMA controller */
DMA_MASTER_CONTROL |= DMA_MASTER_CONTROL_EN;
/* FIQ priority for DMA */
CPU_INT_PRIORITY |= DMA_MASK;
/* Enable request?? Not setting or clearing everything doesn't seem to
* prevent it operating. Perhaps important for reliability (how requests
* are handled). */
DMA_REQ_STATUS |= 1ul << DMA_REQ_IIS;
DMA0_STATUS;
#else
/* Set up banked registers for FIQ mode */
/* Use non-banked registers for scratch. */
register volatile void *iiscfg asm("r0") = &IISCONFIG;
register volatile void *dmapd asm("r1") = &dma_play_data;
asm volatile (
"mrs r2, cpsr \n" /* Save mode and interrupt status */
"msr cpsr_c, #0xd1 \n" /* Switch to FIQ mode */
"mov r8, #0 \n"
"mov r9, #0 \n"
"mov r10, %[iiscfg] \n"
"mov r11, %[dmapd] \n"
"msr cpsr_c, r2 \n"
:
: [iiscfg]"r"(iiscfg), [dmapd]"r"(dmapd)
: "r2");
/* FIQ priority for I2S */
CPU_INT_PRIORITY |= IIS_MASK;
CPU_INT_EN = IIS_MASK;
#endif
IISCONFIG |= IIS_TXFIFOEN;
}
void pcm_postinit(void)
{
audiohw_postinit();
}
const void * pcm_play_dma_get_peak_buffer(int *count)
{
unsigned long addr, size;
int status = disable_fiq_save();
addr = dma_play_data.addr;
size = dma_play_data.size;
restore_fiq(status);
*count = size >> 2;
return (void *)((addr + 2) & ~3);
}
/****************************************************************************
** Recording DMA transfer
**/
#ifdef HAVE_RECORDING
/* PCM recording interrupt routine lockout */
static struct dma_data dma_rec_data IBSS_ATTR =
{
/* Initialize to a locked, stopped state */
{ .addr = 0 },
.size = 0,
#if NUM_CORES > 1
.core = 0x00,
#endif
.locked = 0,
.state = 0
};
/* For the locks, FIQ must be disabled because the handler manipulates
IISCONFIG and the operation is not atomic - dual core support
will require other measures */
void pcm_rec_lock(void)
{
int status = disable_fiq_save();
if (++dma_rec_data.locked == 1)
IIS_IRQRX_REG &= ~IIS_IRQRX;
restore_fiq(status);
}
void pcm_rec_unlock(void)
{
int status = disable_fiq_save();
if (--dma_rec_data.locked == 0 && dma_rec_data.state != 0)
IIS_IRQRX_REG |= IIS_IRQRX;
restore_fiq(status);
}
/* NOTE: direct stack use forbidden by GCC stack handling bug for FIQ */
void fiq_record(void) ICODE_ATTR __attribute__((interrupt ("FIQ")));
#if defined(SANSA_C200) || defined(SANSA_E200)
void fiq_record(void)
{
register pcm_more_callback_type2 more_ready;
register int32_t value;
if (audio_channels == 2) {
/* RX is stereo */
while (dma_rec_data.size > 0) {
if (IIS_RX_FULL_COUNT < 2) {
return;
}
/* Discard every other sample since ADC clock is 1/2 LRCK */
value = IISFIFO_RD;
IISFIFO_RD;
*dma_rec_data.p16++ = value;
dma_rec_data.size -= 4;
/* TODO: Figure out how to do IIS loopback */
if (audio_output_source != AUDIO_SRC_PLAYBACK) {
if (IIS_TX_FREE_COUNT >= 16) {
/* Resync the output FIFO - it ran dry */
IISFIFO_WR = 0;
IISFIFO_WR = 0;
}
IISFIFO_WR = value;
IISFIFO_WR = value;
}
}
}
else {
/* RX is left channel mono */
while (dma_rec_data.size > 0) {
if (IIS_RX_FULL_COUNT < 2) {
return;
}
/* Discard every other sample since ADC clock is 1/2 LRCK */
value = IISFIFO_RD;
IISFIFO_RD;
value = (uint16_t)value | (value << 16);
*dma_rec_data.p16++ = value;
dma_rec_data.size -= 4;
if (audio_output_source != AUDIO_SRC_PLAYBACK) {
if (IIS_TX_FREE_COUNT >= 16) {
/* Resync the output FIFO - it ran dry */
IISFIFO_WR = 0;
IISFIFO_WR = 0;
}
value = *((int32_t *)dma_rec_data.p16 - 1);
IISFIFO_WR = value;
IISFIFO_WR = value;
}
}
}
more_ready = pcm_callback_more_ready;
if (more_ready == NULL || more_ready(0) < 0) {
/* Finished recording */
pcm_rec_dma_stop();
pcm_rec_dma_stopped_callback();
}
}
#else
void fiq_record(void)
{
register pcm_more_callback_type2 more_ready;
while (dma_rec_data.size > 0) {
if (IIS_RX_FULL_COUNT < 2) {
return;
}
#if SAMPLE_SIZE == 16
*dma_rec_data.p16++ = IISFIFO_RD;
#elif SAMPLE_SIZE == 32
*dma_rec_data.p32++ = IISFIFO_RD >> 16;
*dma_rec_data.p32++ = IISFIFO_RD >> 16;
#endif
dma_rec_data.size -= 4;
}
more_ready = pcm_callback_more_ready;
if (more_ready == NULL || more_ready(0) < 0) {
/* Finished recording */
pcm_rec_dma_stop();
pcm_rec_dma_stopped_callback();
}
}
#endif /* SANSA_E200 */
/* Continue transferring data in */
void pcm_record_more(void *start, size_t size)
{
pcm_rec_peak_addr = start; /* Start peaking at dest */
dma_rec_data.addr = (unsigned long)start; /* Start of RX buffer */
dma_rec_data.size = size; /* Bytes to transfer */
}
void pcm_rec_dma_stop(void)
{
/* disable interrupt */
IIS_IRQRX_REG &= ~IIS_IRQRX;
dma_rec_data.state = 0;
dma_rec_data.size = 0;
#if NUM_CORES > 1
dma_rec_data.core = 0x00;
#endif
/* disable fifo */
IISCONFIG &= ~IIS_RXFIFOEN;
IISFIFO_CFG |= IIS_RXCLR;
}
void pcm_rec_dma_start(void *addr, size_t size)
{
pcm_rec_dma_stop();
pcm_rec_peak_addr = addr;
dma_rec_data.addr = (unsigned long)addr;
dma_rec_data.size = size;
#if NUM_CORES > 1
/* This will become more important later - and different ! */
dma_rec_data.core = processor_id(); /* save initiating core */
#endif
/* setup FIQ handler */
fiq_function = fiq_record;
/* interrupt on full fifo, enable record fifo interrupt */
dma_rec_data.state = 1;
/* enable RX FIFO */
IISCONFIG |= IIS_RXFIFOEN;
/* enable IIS interrupt as FIQ */
CPU_INT_PRIORITY |= IIS_MASK;
CPU_INT_EN = IIS_MASK;
}
void pcm_rec_dma_close(void)
{
pcm_rec_dma_stop();
} /* pcm_close_recording */
void pcm_rec_dma_init(void)
{
pcm_rec_dma_stop();
} /* pcm_init */
const void * pcm_rec_dma_get_peak_buffer(int *count)
{
unsigned long addr, end;
int status = disable_fiq_save();
addr = (unsigned long)pcm_rec_peak_addr;
end = dma_rec_data.addr;
restore_fiq(status);
*count = (end >> 2) - (addr >> 2);
return (void *)(addr & ~3);
} /* pcm_rec_dma_get_peak_buffer */
#endif /* HAVE_RECORDING */