i.MX8M Mini, sai5 with multiple data lines

[cpetrescu]

Hi there,

I'm trying to use sai5 in a multi-line configuration on a custom board with an i.MX8M Mini.

There's an audio link between the i.MX8 and a DSP. The bit clock and the frame clock are generated by an external clock generator.

I can play and record audio (8 channels) as long as I use only one data line (RX_DATA0 and TX_DATA0).

The working device tree fragment is the following:

&sai5 {
	status = "okay";
	fsl,sai-asynchronous;
	#sound-dai-cells = <1>;
};

/ {
	dsp0: fixed_tdm_dummy_codec0 {
		#sound-dai-cells = <1>;
		compatible = "test,fixed_tdm";
	};

	card0: sound {
		#address-cells = <1>;
		#size-cells = <0>;
		status = "okay";
		compatible = "simple-audio-card";
		simple-audio-card,name = "dsp0";
		simple-audio-card,format = "left_j";
		simple-audio-card,bitclock-master = <&link0_codec>;
		simple-audio-card,frame-master = <&link0_codec>;

		simple-audio-card,dai-link@0 {
			reg = <0>;
			format = "left_j";
			link0_cpu: cpu {
				sound-dai = <&sai5 0>;
			};
			link0_codec: codec {
				sound-dai = <&dsp0 0>;
				dai-tdm-slot-num = <8>;
				dai-tdm-slot-width = <32>;
				frame-master;
				bitclock-master;
			};
		};
	};
};

When I try to add another data line, the simple-card driver fails to load.
asoc_simple_parse_dai returns -EINVAL when it tries to parse the CPU component of the second dai link.
If I try to use only RX_DATA1, TX_DATA1, the simple-card probe fails the same way.

The following two device tree fragments fail:

&sai5 {
	status = "okay";
	fsl,sai-asynchronous;
	#sound-dai-cells = <1>;
	fsl,dataline = <8 0x0f 0x0f>;
	fsl,sai-multi-lane;
};

/ {
	dsp0: fixed_tdm_dummy_codec0 {
		#sound-dai-cells = <1>;
		compatible = "test,fixed_tdm";
	};

	card0: sound {
		#address-cells = <1>;
		#size-cells = <0>;
		status = "okay";
		compatible = "simple-audio-card";
		simple-audio-card,name = "dsp0";

		simple-audio-card,dai-link@0 {
			reg = <0>;
			format = "left_j";
			bitclock-master = <&link0_master>;
			frame-master = <&link0_master>;
			link0_cpu: cpu {
				sound-dai = <&sai5 0>;
			};
			link0_master: codec {
				sound-dai = <&dsp0 0>;
				dai-tdm-slot-num = <8>;
				dai-tdm-slot-width = <32>;
				frame-master;
				bitclock-master;
			};
		};

		simple-audio-card,dai-link@1 {
			reg = <1>;
			format = "left_j";
			bitclock-master = <&link1_master>;
			frame-master = <&link1_master>;
			cpu {
				sound-dai = <&sai5 1>;
			};
			link1_master: codec {
				sound-dai = <&dsp0 1>;
				dai-tdm-slot-num = <8>;
				dai-tdm-slot-width = <32>;
				frame-master;
				bitclock-master;
			};
		};
	};
};

&sai5 {
	status = "okay";
	fsl,sai-asynchronous;
	#sound-dai-cells = <1>;
};

/ {
	dsp0: fixed_tdm_dummy_codec0 {
		#sound-dai-cells = <1>;
		compatible = "test,fixed_tdm";
	};

	card0: sound {
		#address-cells = <1>;
		#size-cells = <0>;
		status = "okay";
		compatible = "simple-audio-card";
		simple-audio-card,name = "dsp0";
		simple-audio-card,format = "left_j";
		simple-audio-card,bitclock-master = <&link0_codec>;
		simple-audio-card,frame-master = <&link0_codec>;

		simple-audio-card,dai-link@0 {
			reg = <0>;
			format = "left_j";
			link0_cpu: cpu {
				sound-dai = <&sai5 0>;
			};
			link0_codec: codec {
				sound-dai = <&dsp0 0>;
				dai-tdm-slot-num = <8>;
				dai-tdm-slot-width = <32>;
				frame-master;
				bitclock-master;
			};
		};
	};
};

 When the simple-card driver fails to load, it prints:

[    7.289407] asoc-simple-card: probe of sound failed with error -22

Has anyone been able to use these SAIs with multiple data lines?

Thanks in advance for any feedback.