RT-Thread Audio - 1. 音频框架的分析
本帖最后由 sunsili 于 2021-12-9 13:59 编辑RT-Thread Audio - 1. 音频框架的分析
Github 上 RT-Thread 源码最新更新了关于 Audio 驱动相关的部分，让上层和底层都开发和编程简单了，不过对于大部分的开发者来说还不太熟悉这套框架的，那么笔者就这次编写音频驱动给大家分析下代码框架。
这里会先贴一张框架图，整个帖子都是笔者在编写开发过程中写的，可能有格式和错误，最终全部更新完毕后会整理整个系列的帖子。
1. RT-Thread 音频架构图
2. RT-Thread 音频框架的调用逻辑关系图(建议右键大图)
3. RT-Thread 音频应用代码模板(以wavplay为例)
https://github.com/RT-Thread-packages/wavplayer
4. RT-Thread 音频驱动代码模板
#include "drv_sound.h"
#include "drv_tina.h"
#include "drivers/audio.h"
#define DBG_TAG "drv_sound"
#define DBG_LVL DBG_LOG
#define DBG_COLOR
#include
#define TX_DMA_FIFO_SIZE (2048)
struct temp_sound
{
struct rt_audio_device device;
struct rt_audio_configure replay_config;
int volume;
rt_uint8_t *tx_fifo;
};
static rt_err_t getcaps(struct rt_audio_device *audio, struct rt_audio_caps *caps)
{
struct temp_sound *sound = RT_NULL;
RT_ASSERT(audio != RT_NULL);
sound = (struct temp_sound *)audio->parent.user_data; (void)sound;
return RT_EOK;
}
static rt_err_t configure(struct rt_audio_device *audio, struct rt_audio_caps *caps)
{
struct temp_sound *sound = RT_NULL;
RT_ASSERT(audio != RT_NULL);
sound = (struct temp_sound *)audio->parent.user_data; (void)sound;
return RT_EOK;
}
static rt_err_t init(struct rt_audio_device *audio)
{
struct temp_sound *sound = RT_NULL;
RT_ASSERT(audio != RT_NULL);
sound = (struct temp_sound *)audio->parent.user_data; (void)sound;
return RT_EOK;
}
static rt_err_t start(struct rt_audio_device *audio, int stream)
{
struct temp_sound *sound = RT_NULL;
RT_ASSERT(audio != RT_NULL);
sound = (struct temp_sound *)audio->parent.user_data; (void)sound;
return RT_EOK;
}
static rt_err_t stop(struct rt_audio_device *audio, int stream)
{
struct temp_sound *sound = RT_NULL;
RT_ASSERT(audio != RT_NULL);
sound = (struct temp_sound *)audio->parent.user_data; (void)sound;
return RT_EOK;
}
rt_size_t transmit(struct rt_audio_device *audio, const void *writeBuf, void *readBuf, rt_size_t size)
{
struct temp_sound *sound = RT_NULL;
RT_ASSERT(audio != RT_NULL);
sound = (struct temp_sound *)audio->parent.user_data; (void)sound;
return size;
}
static void buffer_info(struct rt_audio_device *audio, struct rt_audio_buf_info *info)
{
struct temp_sound *sound = RT_NULL;
RT_ASSERT(audio != RT_NULL);
sound = (struct temp_sound *)audio->parent.user_data;
/**
* TX_FIFO
* +----------------+----------------+
* | block1 | block2 |
* +----------------+----------------+
* \ block_size /
*/
info->buffer = sound->tx_fifo;
info->total_size = TX_DMA_FIFO_SIZE;
info->block_size = TX_DMA_FIFO_SIZE / 2;
info->block_count = 2;
}
static struct rt_audio_ops ops =
{
.getcaps = getcaps,
.configure = configure,
.init = init,
.start = start,
.stop = stop,
.transmit = transmit,
.buffer_info = buffer_info,
};
static int rt_hw_sound_init(void)
{
rt_uint8_t *tx_fifo = RT_NULL;
static struct temp_sound sound = {0};
/* 分配 DMA 搬运 buffer */
tx_fifo = rt_calloc(1, TX_DMA_FIFO_SIZE);
if(tx_fifo == RT_NULL)
{
return -RT_ENOMEM;
}
sound.tx_fifo = tx_fifo;
/* 注册声卡放音驱动 */
sound.device.ops = &ops;
rt_audio_register(&sound.device, "sound0", RT_DEVICE_FLAG_WRONLY, &sound);
return RT_EOK;
}
INIT_DEVICE_EXPORT(rt_hw_sound_init);
5. 代码分析
待后续补充。。。
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