Suggestion for improving the Sitara Linux Audio DAC Example

BrianBrianBrian

Other Parts Discussed in Thread: PCM5102A

I was going through your Audio DAC example:

processors.wiki.ti.com/.../Sitara_Linux_Audio_DAC_Example

and I got everything working. Then as I was studying the rest of ALSA/ASoC I found the ASoC simple card support layer (simple-card.c) which can be used to completely replace davinci-evm.c with just entries in the device tree. For example, the tutorial could be reduced to just creating the codec driver and then adding the following to your device tree:

  sound {
    compatible = "simple-audio-card";
    simple-audio-card,format = "i2s";

    simple-audio-card,cpu {
      sound-dai = <&mcasp0>;
      bitclock-master;
      bitclock-inversion;
      frame-master;
      system-clock-frequency = <24000000>;
      system-clock-direction = "out";
    };

    simple-audio-card,codec {
      sound-dai = <&pcm5102a>;      
    };
    
  };

This describes to the simple card support layer how to create the DAI link between the codec and McASP. I hope this helps others!

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Thanks for this contribution Brian!

0 Levy Oliveira over 7 years ago

Intellectual 360 points

Hi Brian,

First, thanks for this contribution!

Let me ask you some basic questions:

1) Is it necessary to add something to the "sound/soc/davinci/Kconfig" as in the original example? If so, could you post what is it?
2) In the device tree, do I still have to set the pinmuxing, add the mcasp node and add a node to the pcm5102a? like bellow:

pcm5102a: pcm5102a {
compatible = "ti,pcm5102a";
};
3) Could you post the complete .dts?

Thanks in advance!

0 Levy Oliveira over 7 years ago

Intellectual 360 points

Hi Brian,

I am trying your improvement, but I get the following error:

root@am335x-evm:~# dmesg | grep -i simple

[ 1.246382] /sound/simple-audio-card,cpu: could not get #sound-dai-cells for /ocp/mcasp@48038000

[ 1.255240] asoc-simple-card sound: parse error -22

[ 1.260385] asoc-simple-card: probe of sound failed with error -22

I am using PROCESSOR SDK 03.02.00.05 and Beaglebone white.

My am335x-bone.dts file is:

/*
 * Copyright (C) 2012 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.
 */
/dts-v1/;

#include "am33xx.dtsi"
#include "am335x-bone-common.dtsi"

/ {
	model = "TI AM335x BeagleBone";
	compatible = "ti,am335x-bone", "ti,am33xx";
};

&ldo3_reg {
	regulator-min-microvolt = <1800000>;
	regulator-max-microvolt = <3300000>;
	regulator-always-on;
};

&mmc1 {
	vmmc-supply = <&ldo3_reg>;
};

&sgx {
	status = "okay";
};

&am33xx_pinmux {
	mcasp0_pins: mcasp0_pins {
		pinctrl-single,pins = <
			0x190 (PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* mcasp0_aclkx */
			0x194 (PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* mcasp0_fsx*/
			0x198 (PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* mcasp0_axr0 */
		>;
	};
};
 
&mcasp0 {
		pinctrl-names = "default";
		pinctrl-0 = <&mcasp0_pins>;
		status = "okay";
		op-mode = <0>;          /* MCASP_IIS_MODE */
		tdm-slots = <2>;
		/* 16 serializer */
		serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
			1 0 0 0
		>;
		tx-num-evt = <32>;
		rx-num-evt = <32>;
};
 
/{

pcm5102a: pcm5102a{
	compatible = "ti,pcm5102a";
};

sound {
	  compatible = "simple-audio-card";
	  simple-audio-card,format = "i2s";
	  simple-audio-card,cpu {
		    sound-dai = <&mcasp0>;
		    bitclock-master;
		    bitclock-inversion;
		    frame-master;
		    system-clock-frequency = <24000000>;
		    system-clock-direction = "out";
		  };

	 
	  simple-audio-card,codec {
	    sound-dai = <&pcm5102a>;      
	  };
  
};
};

Thanks in advance!

0 Levy Oliveira over 7 years ago in reply to Levy Oliveira

Intellectual 360 points

Hi,

from a Brian's post elsewhere in E2E, I realized that "#sound-dai-cells = <0>;" is necessary in MCASP and PCM5102A nodes.

Here is the am335x-bone.dts that works:

/*
 * Copyright (C) 2012 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.
 */
/dts-v1/;

#include "am33xx.dtsi"
#include "am335x-bone-common.dtsi"

/ {
	model = "TI AM335x BeagleBone";
	compatible = "ti,am335x-bone", "ti,am33xx";
};

&ldo3_reg {
	regulator-min-microvolt = <1800000>;
	regulator-max-microvolt = <3300000>;
	regulator-always-on;
};

&mmc1 {
	vmmc-supply = <&ldo3_reg>;
};

&sgx {
	status = "okay";
};

&am33xx_pinmux {
	mcasp0_pins: mcasp0_pins {
		pinctrl-single,pins = <
			0x190 (PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* mcasp0_aclkx */
			0x194 (PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* mcasp0_fsx*/
			0x198 (PIN_OUTPUT_PULLDOWN | MUX_MODE0)	/* mcasp0_axr0 */
		>;
	};
};
 
&mcasp0 {
		#sound-dai-cells = <0>;		
		pinctrl-names = "default";
		pinctrl-0 = <&mcasp0_pins>;
		status = "okay";
		op-mode = <0>;          /* MCASP_IIS_MODE */
		tdm-slots = <2>;
		/* 16 serializer */
		serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
			1 0 0 0
		>;
		tx-num-evt = <32>;
		rx-num-evt = <32>;
};
 
/{

pcm5102a: pcm5102a{
	#sound-dai-cells = <0>;	
	compatible = "ti,pcm5102a";
};

sound {
	  compatible = "simple-audio-card";
	  simple-audio-card,format = "i2s";
	  simple-audio-card,cpu {
		    sound-dai = <&mcasp0>;
		    bitclock-master;
		    bitclock-inversion;
		    frame-master;
		    system-clock-frequency = <24000000>;
		    system-clock-direction = "out";
		  };

	 
	  simple-audio-card,codec {
		sound-dai = <&pcm5102a>;      
	  };
  
};
};

Best regards,

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Suggestion for improving the Sitara Linux Audio DAC Example