BEAGL-BONE-BLACK: How to interface multiple I2S devices in arago Linux.

Hello Shantanu,

Please share your configuration for multiple I2S configuration.

Regards,
Krunal

Hello,

For I2S 1, I am using following pinmux:

P9_42 - clock

P9_41 - data

P9_27 - frame sync

For I2S 2, I am using following pinmux:

P8_35 - clock

P8_36 - data

P8_38 - frame sync

I want both the devices should works at same time.

Thanks,

Shantanu

Hello Shantanu,

Please send your DT file with both configuration enabled and the errors that you are running into. Also, refer to the following document: https://www.ti.com/lit/an/sprac97/sprac97.pdf?ts=1613771096259&ref_url=https%253A%252F%252Fwww.google.com%252F It shows how to enable a single McASP but same concept would apply to another McASP.

Regards,
Krunal

Hello,

I have tried with the following DT file for using multiple I2S configurations. But it doesn't work for me. It is still showing only one device while running "arecord -l" command.

/*
* Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. 
*/

&am33xx_pinmux {
	mcasp1_pins: mcasp1_pins {
		pinctrl-single,pins = <
 		/* sink must enable receivers */
   		AM33XX_IOPAD(0x9a0, PIN_INPUT_PULLDOWN | 	MUX_MODE3) /* P9_42 mcasp1_aclkx - bit clock */
		AM33XX_IOPAD(0x9a4, PIN_INPUT_PULLDOWN | MUX_MODE3) /* P9_27 mcasp1_fsx - frame sync */
   		0x1a8 0x23 /* P9_41 mcasp1_axr0 - i2s input */
		>;	
	};
	mcasp0_pins: mcasp0_pins {
		pinctrl-single,pins = <
 		/* sink must enable receivers */
   		AM33XX_IOPAD(0x8d0, PIN_INPUT_PULLDOWN | 	MUX_MODE3) /* P8_35 mcasp1_aclkx - bit clock */
		AM33XX_IOPAD(0x8c4, PIN_INPUT_PULLDOWN | MUX_MODE3) /* P8_38 mcasp1_fsx - frame sync */
   		0x0c8 0x23 /* P8_36 mcasp1_axr0 - i2s input */
		>;
	};
};
&mcasp1 {
	#sound-dai-cells = <0>;
	pinctrl-names = "default";
	pinctrl-0 = <&mcasp1_pins>;
	status = "okay";
	op-mode = <0>; /* MCASP_IIS_MODE */
	tdm-slots = <2>;
	num-serializer = <4>;
	serial-dir = < /* 1 TX 2 RX 0 unused */
		2 1 0 0
	>;
	rx-num-evt = <8>;
	tx-num-evt = <8>;
};
&mcasp0 {
	#sound-dai-cells = <0>;
	pinctrl-names = "default";
	pinctrl-0 = <&mcasp0_pins>;
	status = "okay";
	op-mode = <0>; /* MCASP_IIS_MODE */
	tdm-slots = <10>;
	num-serializer = <4>;
	serial-dir = < /* 1 TX 2 RX 0 unused */
		2 1 0 0
	>;
	rx-num-evt = <32>;
	tx-num-evt = <32>;
};
/ {
	pcm5102a: pcm5102a {
		#sound-dai-cells = <0>;
		compatible = "ti,pcm5102a";
		status = "okay";
};

clk_mcasp1_fixed: clk_mcasp1_fixed {
  #clock-cells = <0>;
  compatible = "fixed-clock";
  clock-frequency = <24576000>;
 };

clk_mcasp1: clk_mcasp1 {
  #clock-cells = <0>;
  compatible = "gpio-gate-clock";
  clocks = <&clk_mcasp1_fixed>;
  enable-gpios = <&gpio1 27 0>; /* BeagleBone Black Clk enable on GPIO1_27 */
 };

clk_mcasp0_fixed: clk_mcasp0_fixed {
  #clock-cells = <0>;
  compatible = "fixed-clock";
  clock-frequency = <24576000>;
 };

clk_mcasp0: clk_mcasp0 {
  #clock-cells = <0>;
  compatible = "gpio-gate-clock";
  clocks = <&clk_mcasp0_fixed>;
  enable-gpios = <&gpio1 38 0>; /* BeagleBone Black Clk enable on GPIO1_27 */
 };

sound1: sound@1 {
compatible = "simple-audio-card";
simple-audio-card,name = "PCM5102a";
simple-audio-card,format = "i2s";
simple-audio-card,bitclock-master = <&sound1_master>;
simple-audio-card,frame-master = <&sound1_master>;
simple-audio-card,bitclock-inversion;

sound1_master: simple-audio-card,cpu {
sound-dai = <&mcasp1>;
system-clock-direction = "out";
   system-clock-frequency = <24576000>;
   clocks = <&clk_mcasp1>;
};

simple-audio-card,codec {
#sound-dai-cells = <0>;
sound-dai = <&pcm5102a>;
/*clocks = <&mcasp1_fck>;
clock-names = "mclk";*/
};
};

sound0: sound@0 {
compatible = "simple-audio-card";
simple-audio-card,name = "PCM5102a";
simple-audio-card,format = "i2s";
simple-audio-card,bitclock-master = <&sound0_master>;
simple-audio-card,frame-master = <&sound0_master>;
simple-audio-card,bitclock-inversion;

sound0_master: simple-audio-card,cpu {
sound-dai = <&mcasp0>;
system-clock-direction = "out";
   system-clock-frequency = <24576000>;
   clocks = <&clk_mcasp0>;
};

simple-audio-card,codec {
#sound-dai-cells = <0>;
sound-dai = <&pcm5102a>;
/*clocks = <&mcasp1_fck>;
clock-names = "mclk";*/
};
};

};

Thank you,

Shantanu

Hi Shantanu,

Please correct me if I am wrong but McASP 0 also works if McASP 1 is not defined. Based on your configuration, I believe you many need to create another instance of the dummy codec. For example, in the sound node, simple-audio-card name point to PCM5102a for both McASPs. I am not sure if that is the correct config and as an experiment, try creating two instances of dummy codec and let me know your observations.  

Regards,
Krunal

Hello,

Yes, McASP 0 is working when McASP 1 is  not defined.

I have created separate DT file for McASP 0, In that I have used same dummy codec i.e. PCM5102a but it doesn't work for me. Is there any other dummy codec for that will be used for I2S? OR I have to use PCM5102 twice?

Thanks,

Shantanu

Hello Shantanu,

Defining McASP0 instance in another file is equivalent of defining it in a single file. We have not tested the above usecase and I would try to create another instance of the dummy codec and see if that helps?

Regards,
Krunal

Hello Sir,

Have you tried with another dummy codec? If it's working can you please help me with that.

Thanks and regards,

Shantanu

Hello,

We did not test the above usecase as part of our SDK and please share what errors you are observing. 

Regards,
Krunal

Hello,

Is there any sample C code to run I2S on Beagle-bone black. or Is there any other method to run I2S without using 'arecord' command.

Thanks and regards,

Shantanu

Hello Shantanu,

Unfortunately, we do not provide any C code examples.

Regards,
Krunal