AM3358: MCASP audio no data on TX

Samer Abbas

Part Number: AM3358

Hi,

I am interfacing AM3358 with an audio codec. I am having a problem where I am only seeing data on RX, but nothing on TX of MCASP. The audio codec I am using is Si32178 by Silicon Labs. I have it connected as following:

MCASP1_CLKX --> PCLK (Audio Codec)

MCASP1_FSX --> FSYNC (Audio Codec)

MCASP1_AXR0 (TX) --> DRX (Audio Codec)

MCASP1_AXR1 (RX) --> DTX (Audio Codec)

Here is part of my device tree:

voip_audio_pins: pinmux_voip_audio_pins {
                                pinctrl-single,pins = <
                                        AM33XX_IOPAD(0x9a0, PIN_INPUT_PULLDOWN | MUX_MODE3)     /* mcasp0_aclkr.mcasp1_aclkx */
                                        AM33XX_IOPAD(0x9a4, PIN_INPUT_PULLDOWN | MUX_MODE3)     /* mcasp0_fsr.mcasp1_fsx, INPUT */
                                        AM33XX_IOPAD(0x9a8, PIN_OUTPUT_PULLDOWN | MUX_MODE2)    /* mcasp0_axr1.mcasp1_axr0 */
                                        AM33XX_IOPAD(0x9ac, PIN_INPUT_PULLDOWN | MUX_MODE3)     /* mcasp0_ahclkr.mcasp1_axr1 */

                                >;
                        };


&mcasp1 {
        #sound-dai-cells = <0>;
        pinctrl-names = "default";
        pinctrl-0 = <&voip_audio_pins>;
        status = "okay";
        op-mode = <0>;  /* MCASP_IIS_MODE */
        tdm-slots = <8>;
        num-serializer = <4>;
        serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
                        1 2 0 0
                >;
        tx-num-evt = <8>;
        rx-num-evt = <8>;
                };

I am seeing data on MCASP1_AXR1 (RX) --> DTX , but I don't see anything on MCASP1_AXR0 (TX) --> DRX (Audio Codec) even when audio input is coming.

What could be going wrong here?

over 4 years ago

0 Krunal Bhargav34 over 4 years ago

TI__Mastermind 44735 points

Hello,

Could you please share the sound node?

Regards,
Krunal

0 Samer Abbas over 4 years ago in reply to Krunal Bhargav34

Expert 1055 points

Hi Krunal,

This codec requires PCM/TDM so I am using "dsp_b" format. Here is the sound node:

sound{
                                compatible = "simple-audio-card";
                                simple-audio-card,name = "SI32178";

                                        simple-audio-card,format = "dsp_b";
                                        simple-audio-card,bitclock-master = <&sound_master>;
                                        simple-audio-card,frame-master = <&sound_master>;
                                        simple-audio-card,bitclock-inversion;
                                        simple-audio-card,cpu {
                                                sound-dai = <&mcasp1>;
                                        };
                                        sound_master: simple-audio-card,codec {
                                                sound-dai = <&si32178>;
                                                clocks = <&clk_mcasp1_fixed>;
                                                clock-names = "bclk";
					};
                       };

Thank you

0 Krunal Bhargav34 over 4 years ago in reply to Samer Abbas

TI__Mastermind 44735 points

Hello,

I am wondering if you have probed the clocks and data lines to check for any activities.

Regards,
Krunal

0 Samer Abbas over 4 years ago in reply to Krunal Bhargav34

Expert 1055 points

Hi Krunal,

I have probed clocks and data lines. I have clocks at BCLK and FSX, and I do see data on MCASP1_AXR1 (RX) --> DTX, but there is no data on MCASP1_AXR0 (TX) --> DRX.

Thank you

0 Krunal Bhargav34 over 4 years ago in reply to Samer Abbas

TI__Mastermind 44735 points

Hello,

In your boot logs, do you see any pin conflict messages and while running app, do you any any errors messages? Also, please share more information on how you are transmitting data from McASP (ie gtsreamer or aplay).

Regards,
Krunal

0 Samer Abbas over 4 years ago in reply to Krunal Bhargav34

Expert 1055 points

There are no pin conflict or error messages. Yes I am using aplay for playback and its not giving any audio.

Thank you

0 Samer Abbas over 4 years ago in reply to Krunal Bhargav34

Expert 1055 points

Hi Krunal,

One other thing I have tested is that when I connect the audio codec on MCASP0, I am able to get audio on TX but then I don't get any audio on Rx.

When I connect audio on MCASP1, then I only get audio on Rx and nothing on Tx.

In both situations I am connecting the codec on Transmit pins of MCASP0 or MCASP1.

Thank you

0 Samer Abbas over 4 years ago in reply to Krunal Bhargav34

Expert 1055 points

In my original setup of codec on MCASP1, I found this error:

davinci-mcasp 48038000.mcasp: unhandled tx event. txstat: 0x0000010c

Thank you

0 Krunal Bhargav34 over 4 years ago in reply to Samer Abbas

TI__Mastermind 44735 points

Hello,

Did you use the pin mux tool for the McASP pin configuration? If yes, please share a screen shot of the McASP pin config.

Regards,
Krunal

0 Samer Abbas over 4 years ago in reply to Krunal Bhargav34

Expert 1055 points

Krunal,

Yes, and you can see my McASP pin config in my post above.

Thank you

0 Krunal Bhargav34 over 4 years ago in reply to Samer Abbas

TI__Mastermind 44735 points

Hello,

Could you please share how you created it because I am not able to generate the same pins as you? Here is my output:

Regards,
Krunal

+1 Samer Abbas over 4 years ago in reply to Krunal Bhargav34

Expert 1055 points

Hi Krunal,

You have the wrong package selected. I am using ZCZ package.

I figured out my problem. I was setting wrong MUX_MODE for MCASP1_AXR0. The correct mux_mode was 3.

Thanks for your help.

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AM3358: MCASP audio no data on TX