RK3399 ALC5640芯片配置

说明：本文适用于 RK3399 linux 4.4 内核系列SDK。硬件上，音频外部 codec 芯片 i2s 引脚与 RK3399 i2s1连接。软件上需要加下述patch解决噪声问题（以 rt5640 为例）

arch/arm64/boot/dts/rockchip/rk3399-firefly-linux.dts

/ {
    rt5640-sound {
        status = "okay";    
        compatible = "simple-audio-card";
        simple-audio-card,format = "i2s";
        simple-audio-card,name = "rockchip,rt5640-codec";
        simple-audio-card,mclk-fs = <256>;
        simple-audio-card,widgets =
            "Microphone", "Mic Jack",
            "Headphone", "Headphone Jack";
        simple-audio-card,routing =
            "Mic Jack", "MICBIAS1",
            "IN1P", "Mic Jack",
            "Headphone Jack", "HPOL",
            "Headphone Jack", "HPOR";    
        simple-audio-card,cpu {
                sound-dai = <&i2s1>;
        };
        simple-audio-card,codec {
                sound-dai = <&rt5640>;
        };
    };
};

&i2s1 {
    status = "okay";
    #sound-dai-cells = <0>;
    rockchip,i2s-broken-burst-len;
    rockchip,playback-channels = <2>;
    rockchip,capture-channels = <2>;
    //assigned-clocks = <&cru SCLK_I2S_8CH>;
    //assigned-clock-parents =<&cru SCLK_I2S1_8CH>;
};

&i2c1 {
    status = "okay";
    rt5640: rt5640@1c {
        #sound-dai-cells = <0>;
        compatible = "realtek,rt5640";
        reg = <0x1c>;
        clocks = <&cru SCLK_I2S_8CH_OUT>;
        clock-names = "mclk";
        realtek,in1-differential;
        realtek,in2-differential;
        pinctrl-names = "default";
        pinctrl-0 = <&i2s_8ch_mclk>;
        status = "okay";
    };
};

arch/arm64/boot/dts/rockchip/rk3399-vop-clk-set.dtsi 

/*
&i2s1 {
        assigned-clocks = <&cru SCLK_I2S1_DIV>;
        assigned-clock-parents = <&cru PLL_GPLL>;
};
*/

&i2s1 {
        assigned-clocks = <&cru SCLK_I2S_8CH>;
        assigned-clock-parents =<&cru SCLK_I2S1_8CH>;
};

时钟配置
diff --git a/drivers/clk/rockchip/clk-rk3399.c b/drivers/clk/rockchip/clk-rk3399.c
index f434454..f5822f0 100644
--- a/drivers/clk/rockchip/clk-rk3399.c
+++ b/drivers/clk/rockchip/clk-rk3399.c

@@ -712,7 +712,7 @@ static struct rockchip_clk_branch rk3399_clk_branches[] __initdata = {
     GATE(SCLK_I2S2_8CH, "clk_i2s2", "clk_i2s2_mux", CLK_SET_RATE_PARENT,
             RK3399_CLKGATE_CON(8), 11, GFLAGS),
 
-    MUX(0, "clk_i2sout_src", mux_i2sch_p, CLK_SET_RATE_PARENT,
+    MUX(SCLK_I2S_8CH, "clk_i2sout_src", mux_i2sch_p, CLK_SET_RATE_PARENT,
             RK3399_CLKSEL_CON(31), 0, 2, MFLAGS),
     COMPOSITE_NODIV(SCLK_I2S_8CH_OUT, "clk_i2sout", mux_i2sout_p, CLK_SET_RATE_PARENT,
             RK3399_CLKSEL_CON(30), 8, 2, MFLAGS,

   
diff --git a/include/dt-bindings/clock/rk3399-cru.h b/include/dt-bindings/clock/rk3399-cru.h
index d32ce01..710d610 100644
--- a/include/dt-bindings/clock/rk3399-cru.h
+++ b/include/dt-bindings/clock/rk3399-cru.h

@@ -226,6 +226,7 @@
 #define ACLK_GIC_PRE             262
 #define ACLK_VOP0_PRE             263
 #define ACLK_VOP1_PRE             264
+#define SCLK_I2S_8CH            265
 
 /* pclk gates */
 #define PCLK_PERIHP            320