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
