IMX8QM ESAI0 EXTAL MCLK

dhty2015 — Mon, 15 Jun 2020 07:59:28 GMT

我现在使用imx8qmCPU，当前使用ESAI0主模式tdm模式驱动8声道声卡。我的dts中：

&esai0 {
compatible = "fsl,imx8qm-esai";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_esai0>;
assigned-clocks = <&clk IMX8QM_ACM_ESAI0_MCLK_SEL>,
<&clk IMX8QM_AUD_PLL0_DIV>,
<&clk IMX8QM_AUD_ACM_AUD_PLL_CLK0_DIV>,
<&clk IMX8QM_AUD_ACM_AUD_REC_CLK0_DIV>,
<&clk IMX8QM_AUD_ESAI_0_EXTAL_IPG>;
assigned-clock-parents = <&clk IMX8QM_AUD_ACM_AUD_PLL_CLK0_CLK>;
assigned-clock-rates = <0>, <786432000>, <49152000>, <12288000>, <49152000>;
fsl,txm-rxs;
status = "okay";
};

我音频为48K采样率，32位深，8声道。所以我需要24576000的MCLK输出。

现在问题是：

当前EXTAL频率为49152000，需要进行2分频作为输出。但是

NOTE: Do not use the combination TPSR = 1 and TPM7-RPM0 = 0x00, which causes synchronization

problems when using the internal core clock as source (THCKD = 1 or TCKD = 1).

TPSR无法和TPM=0且MCLK为输出时共存，导致无法对EXTAL二分频。

请问：

如何使用EXTAL二分频作为MCLK；

如何修改EXTAL为其他频率比如24576000或者98304000

多谢！

Re: IMX8QM ESAI0 EXTAL MCLK

igorpadykov — Mon, 15 Jun 2020 08:50:44 GMT

Hi dhty2015

for esai mclk clock change one can look at

ESAI peripheral generating incorrect I2S frequencies

pay attention to esai clocks:

assigned-clock-rates = <0>, <786432000>, <49152000>, <12288000>, <49152000>;

fsl-imx8qm-mek.dtsi\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel

Best regards
igor
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topic IMX8QM ESAI0 EXTAL MCLK in i.MX Processors

IMX8QM ESAI0 EXTAL MCLK

Re: IMX8QM ESAI0 EXTAL MCLK