incubator-nuttx/libs/libc/audio/lib_buffer.c

142 lines
4.1 KiB
C

/****************************************************************************
* libs/libc/audio/lib_buffer.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/audio/audio.h>
#include <nuttx/usb/audio.h>
#include "libc.h"
#if defined(CONFIG_AUDIO)
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: apb_alloc
*
* Allocate an Audio Pipeline Buffer for use in the Audio sub-system. This
* will perform the actual allocate based on buffer data format, number of
* channels, etc. and prepare the buffer for consumption.
*
****************************************************************************/
int apb_alloc(FAR struct audio_buf_desc_s *bufdesc)
{
uint32_t bufsize;
int ret;
struct ap_buffer_s *apb;
DEBUGASSERT(bufdesc->u.pbuffer != NULL);
/* Perform a user mode allocation */
bufsize = sizeof(struct ap_buffer_s) + bufdesc->numbytes;
apb = lib_umalloc(bufsize);
*bufdesc->u.pbuffer = apb;
/* Test if the allocation was successful or not */
if (*bufdesc->u.pbuffer == NULL)
{
ret = -ENOMEM;
}
else
{
/* Populate the buffer contents */
memset(apb, 0, bufsize);
apb->i.channels = 1;
apb->crefs = 1;
apb->nmaxbytes = bufdesc->numbytes;
apb->nbytes = 0;
apb->flags = 0;
apb->samp = (FAR uint8_t *)(apb + 1);
#ifdef CONFIG_AUDIO_MULTI_SESSION
apb->session = bufdesc->session;
#endif
nxmutex_init(&apb->lock);
ret = sizeof(struct audio_buf_desc_s);
}
return ret;
}
/****************************************************************************
* Name: apb_free
*
* Free's a previously allocated or referenced Audio Pipeline Buffer
*
****************************************************************************/
void apb_free(FAR struct ap_buffer_s *apb)
{
int refcount;
/* Perform a reference count decrement and possibly release the memory */
nxmutex_lock(&apb->lock);
refcount = apb->crefs--;
nxmutex_unlock(&apb->lock);
if (refcount <= 1)
{
audinfo("Freeing %p\n", apb);
nxmutex_destroy(&apb->lock);
lib_ufree(apb);
}
}
/****************************************************************************
* Name: apb_reference
*
* Claim a reference to an Audio Pipeline Buffer. Each call to apb_reference
* will increment the reference count and must have a matching apb_free
* call. When the refcount decrements to zero, the buffer will be freed.
*
****************************************************************************/
void apb_reference(FAR struct ap_buffer_s *apb)
{
/* Do we need any thread protection here? Almost certainly... */
nxmutex_lock(&apb->lock);
apb->crefs++;
nxmutex_unlock(&apb->lock);
}
#endif /* CONFIG_AUDIO */