[RK3288][Android6.0] Audio的ASOC驱动及数据结构

Platform: Rockchip

OS: Android 6.0

Kernel: 3.10.92

系统使用ASOC来处理Audio部分，可分为三大部分： Machine, Codec以及Platform.

其中Codec分codec driver以及codec dai driver,Platform分platform driver以及CPU dai driver.

rk_rt5631.c：

Machine driver，和板子相关，所以不同的板子都需要作修改。
rt5631.c：

Codec driver以及Codec dai driver，和平台无关。相关的部分被放在Machine以及Platform驱动中处理。
rk_i2s.c：

Platform下的cpu dai driver，不包含和板子相关的控制，只和平台相关，因为I2S控制器是一定的。
rk_pcm.c：

Platform driver,dma相关控制，用来输出数据到i2s。


注册及重要的数据结构：
Machine driver注册：

rockchip_rt5631_audio_probe ->    rk_rt5631.c

    snd_soc_register_card

snd_soc_card:

static struct snd_soc_card rockchip_rt5631_snd_card = {
.name = "RK_RT5631",
.dai_link = &rk29_dai,
.num_links = 1,
};

snd_soc_dai_link：

static struct snd_soc_dai_link rk29_dai = {
.name = "rt5631",
.stream_name = "rt5631 PCM",
.codec_dai_name = "rt5631-hifi",
.init = rk29_rt5631_init,
.ops = &rk29_ops,
};

Codec以及codec dai driver注册：

rt5631_i2c_probe ->    rt5631.c

    snd_soc_register_codec

snd_soc_codec_driver:

static struct snd_soc_codec_driver soc_codec_dev_rt5631 = {
.probe = rt5631_probe,
.remove = rt5631_remove,
.suspend = rt5631_suspend,
.resume = rt5631_resume,
.set_bias_level = rt5631_set_bias_level,
.reg_cache_size = ARRAY_SIZE(rt5631_reg),
.reg_word_size = sizeof(u16),
.reg_cache_default = rt5631_reg,
.reg_cache_step = 1,
};

snd_soc_dai_driver:

static struct snd_soc_dai_driver rt5631_dai[] = {
{
.name = "rt5631-hifi",
.playback = {
.stream_name = "HIFI Playback",
.channels_min = 1,
.channels_max = 2,
.rates = RT5631_STEREO_RATES,
.formats = RT5631_FORMAT,
},
.capture = {
.stream_name = "HIFI Capture",
.channels_min = 1,
.channels_max = 2,
.rates = RT5631_STEREO_RATES,
.formats = RT5631_FORMAT,
},
.ops = &rt5631_ops,
},
};

Platform driver注册：

rockchip_i2s_probe ->    rk_i2s.c

    rockchip_pcm_platform_register ->

        snd_dmaengine_pcm_register ->

            snd_soc_add_platform

snd_soc_platform_driver：

static const struct snd_soc_platform_driver dmaengine_no_residue_pcm_platform = {
.ops        = &dmaengine_no_residue_pcm_ops,
.pcm_new    = dmaengine_pcm_new,
.pcm_free    = dmaengine_pcm_free,
.probe_order    = SND_SOC_COMP_ORDER_LATE,
};

CPU dai driver注册：

rockchip_i2s_probe ->    rk_i2s.c

    snd_soc_register_component

snd_soc_dai_driver:

static struct snd_soc_dai_driver rockchip_i2s_dai = {
.probe = rockchip_i2s_dai_probe,
.playback = {
.stream_name = "Playback",
.channels_min = 2,
.channels_max = 8,
.rates = ROCKCHIP_I2S_RATES,
.formats = ROCKCHIP_I2S_FORMATS,
},
.capture = {
.stream_name = "Capture",
.channels_min = 2,
.channels_max = 8,
.rates = ROCKCHIP_I2S_RATES,
.formats = ROCKCHIP_I2S_FORMATS,
},
.ops = &rockchip_i2s_dai_ops,
.symmetric_rates = 1,
};

参考：



http://blog.csdn.net/droidphone/article/details/7165482