因做BT录音，需要把mx6的audio port设置为master模式，让mx6输出pcm clock。
配置流程：
1. arch/arm/mach-mx6/booard_mx6_groove.c
配置ssi的id和内部外部口
static struct mxc_audio_platform_data mx6_t6_mic_data = {
.ssi_num = 0,
.src_port = 1,
.ext_port = 4,
};
加载ssi 0 的驱动
imx6q_add_imx_ssi(0, &mx6_mic_board_ssi_pdata)
2. 驱动配置：
配置audio port的clock方向
static int imx_audmux_config(int slave, int master)
{
unsigned int ptcr, pdcr;
slave = slave - 1; //slave =2 ;master =5
master = master - 1;
/* SSI0 mastered by port 5 */
ptcr = MXC_AUDMUX_V2_PTCR_SYN;
pdcr = MXC_AUDMUX_V2_PDCR_RXDSEL(master);
mxc_audmux_v2_configure_port(slave, ptcr, pdcr);
ptcr =MXC_AUDMUX_V2_PTCR_SYN |
MXC_AUDMUX_V2_PTCR_TFSDIR |
MXC_AUDMUX_V2_PTCR_TFSEL(slave) |
MXC_AUDMUX_V2_PTCR_TCLKDIR |
MXC_AUDMUX_V2_PTCR_TCSEL(slave);
pdcr = MXC_AUDMUX_V2_PDCR_RXDSEL(slave);
mxc_audmux_v2_configure_port(master, ptcr, pdcr);
return 0;
}
配置驱动所以的cpu dai
static struct snd_soc_dai_link imx_wm7210_dai[] = {
{
.name = "HiFi",
.stream_name = "HiFi",
.codec_dai_name = "mxc-wm7210",
.codec_name = "mxc_wm7210.0",
.cpu_dai_name = "imx-ssi.0",
.platform_name = "imx-pcm-audio.0",
.init = imx_3stack_wm7210_init,
.ops = &imx_wm7210_hifi_ops,
},
};
配置ssi 为master模式和相关的clock的方向
static int wm7210_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct snd_soc_dai *codec_dai = rtd->codec_dai;
struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
u32 dai_format;
int ret;
unsigned int channels = params_channels(params);
dai_format = SND_SOC_DAIFMT_NB_IF |
SND_SOC_DAIFMT_CBS_CFS| SND_SOC_DAIFMT_I2S;
ret = snd_soc_dai_set_fmt(cpu_dai, dai_format);
ret = snd_soc_dai_set_sysclk(cpu_dai, IMX_SSP_SYS_CLK,0,1);
if (ret < 0)
return ret;
return 0;
}