AM3358: McASP interface

Hi,

You will find detailed description of the AM335x McASP interface in:

Section 7.11 of the AM335x Datasheet Rev. K.
Section 22 of the AM335x Technical Reference Manual Rev. P.

Hi Biser,

I have read both datasheet and TRM. I am having hard time understanding section 22.3.3.1 which explains TDM. Can I use AXR[0] to connect to TX and AXR[1] to connect to RX on the voice chip?  If yes, is there any example of how to set it up in DTS?

Thank you

Hi Biser,

I am trying to write driver for the Voice chip. Can someone explain the serial-dir in following code:

&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>;
};

Thank you

Samer,

Samer Abbas said:

Can I use AXR[0] to connect to TX and AXR[1] to connect to RX on the voice chip?

Yes you can.

Samer Abbas said:

If yes, is there any example of how to set it up in DTS?

You can check AM335x TI PSDK Linux DTS files:

{PSDK}/board-support/linux-4.19.38/arch/arm/boot/dts/am335x-evm.dts

&mcasp1 {
    #sound-dai-cells = <0>;
    pinctrl-names = "default", "sleep";
    pinctrl-0 = <&mcasp1_pins>;
    pinctrl-1 = <&mcasp1_pins_sleep>;

    status = "okay";

    op-mode = <0>;          /* MCASP_IIS_MODE */
    tdm-slots = <2>;
    /* 4 serializers */
    serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
        0 0 1 2
    >;
    tx-num-evt = <32>;
    rx-num-evt = <32>;
};

In this DTS file, AXR[2] is configured for TX, AXR[3] is configure for RX

You can also check am57xx-beagle-x15-common.dtsi file, where AXR[0] is configured for TX, AXR[1] is configured for RX

/* 4 serializers */
    serial-dir = <    /* 0: INACTIVE, 1: TX, 2: RX */
        1 2 0 0

Regards,
Pavel

Samer Abbas said:

I am trying to write driver for the Voice chip. Can someone explain the serial-dir in following code:

In this code you are configuring McASP0 AXR[0] pin for TX (transmit), while rest of the McASP0 AXR[n] pins are inactive.

See also below files:

linux-4.19.38/sound/soc/ti/davinci-mcasp.c

linux-4.19.38/bindings/sound/davinci-mcasp-audio.txt

Regards,
Pavel

Hi Pavel,

Thanks for the response.

My board design is based on beaglebone, so my MCASP1 pins are not available because of RGMII1 connection to LAN8710. On my MCASP0, I have TLV320AIC3104 connected.

Is there anyway I can connect the voice chip to either MCASP0 or MCASP1?

The voice chip requires both SPI and TDM/PCM. I do have pin-outs available for SPI but I am not sure about MCASP.

Thank you,

Samer

Samer,

Yes, you can connect AIC3x codec to McASP0 on your custom board. In BeagleBone Black board, by default we have TDA19988 HDMI transmitter connected to McASP0 module, and you can update this McASP0 node from TDA19988 to TLV320AIC3104:

linux-4.19.38/arch/arm/boot/dts/am335x-boneblack-common.dtsi

You can refer to the below DTS file for example of McASP0 to tlv320aic3007 codec connection:

linux-4.19.38/arch/arm/boot/dts/am335x-wega.dtsi

You can refer to the below DTS file for example of McASP3 to tlv320aic3104 codec connection:

linux-4.19.38/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi

Regards,
Pavel

Pavel,

It seems like there has been a miscommunication. Let me explain my application. On my custom board, I already have AIC3x codec connected to MCASP0, and my MCASP1 pins are not available due to RGMII being used from those pins.

I want to connect one more audio interface for telephony (FXO/FXS) to my custom board and it requires TDM pins. How can I connect this new telephony chip to AM335x while still keeping AIC3x on my MCASP0?

Thank you,

Samer

Samer,

For connection two external audio chips to McASP0, you can refer to below user guides:

Check section 4.2.1.1, we have examples for HDMI Transmitter + DAC, and we also have ADC+ DAC

5.1 Digital Audio Interface Links - we have McASP6 connected with 3 codecs

Regards,
Pavel

Pavel Botev said:

5.1 Digital Audio Interface Links - we have McASP6 connected with 3 codecs

Pavel,

Where can I get more details on this type of situation where one MCASP is connected to multiple codecs?

For my application I will have AIC3x as a audio output device in one scenario, and I will have telephony chip for audio input and output in one scenario, and they both will be connected to MCASP0.

Thank you,

Samer

Samer,

Check below e2e threads:

Regards,
Pavel

Pavel,

Pavel Botev said:

Linux/AM3352: Multi-codec operation with TDM

TI E2E support forums

Part Number: AM3352 Tool/software: Linux Hi, We have a design using an AM335x processor and 3 x TLV320AIC3106 codecs interfaced using a McASP in TDM mode. The topology appears to be similar to the multi-codec case described in SPRAC09A ( http:/...

In this thread you recommend just modifying DTS to add multiple codec support on one MCASP. There is no example of that. Can you please explain what would I have to change in the following DTS to add support for another codec on MCASP1.

sound {
		compatible = "simple-audio-card";
		simple-audio-card,name = "AM335x-EVM";
		simple-audio-card,widgets =
			"Headphone", "Headphone Jack",
			"Line", "Line In";
		simple-audio-card,routing =
			"Headphone Jack",	"HPLOUT",
			"Headphone Jack",	"HPROUT",
			"LINE1L",		"Line In",
			"LINE1R",		"Line In";
		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 = <&tlv320aic3106>;
			system-clock-frequency = <12000000>;
		};
	};

&mcasp1 {
	#sound-dai-cells = <0>;
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&mcasp1_pins>;
	pinctrl-1 = <&mcasp1_pins_sleep>;

	status = "okay";

	op-mode = <0>;          /* MCASP_IIS_MODE */
	tdm-slots = <2>;
	/* 4 serializers */
	serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
		0 0 1 2
	>;
	tx-num-evt = <32>;
	rx-num-evt = <32>;
};

Thank you,

Samer

Samer,

You can refer to EVMK2G DTS file and user guide:

linux-4.19.38/arch/arm/boot/dts/keystone-k2g-evm.dts

We have McASP2 attached to two codecs: TLV320AIC3106 and Sii9022 HDMI transmitter

For general DTS guidelines, refer to below txt file:

linux-4.19.38/Documentation/devicetree/bindings/sound/simple-card.txt

Below e2e thread might be also in help:

Regards,
Pavel

Pavel Botev said:

You can refer to EVMK2G DTS file and user guide:

linux-4.19.38/arch/arm/boot/dts/keystone-k2g-evm.dts

Pavel,

Thank you for the information. I will try the method used in EVMK2G DTS file.

One more thing, in EVMK2G both codecs are connected through I2S, but in my configuration one will be connected through "dsp_b" and the other will be connected through "TDM". Will this cause any issues?

Thank you,

Samer

Samer Abbas said:

One more thing, in EVMK2G both codecs are connected through I2S, but in my configuration one will be connected through "dsp_b" and the other will be connected through "TDM". Will this cause any issues?

The available format options are listed in below file:

linux-kernel/sound/soc/soc-core.c - i2s, right_j, left_j, dsp_a, dsp_b, ac97, pdm, msb, lsb

You can use dsp_b for codec one , and another option for codec 2. This is shown in below DTS files:

linux-4.19.38/arch/arm/boot/dts/stihxxx-b2120.dtsi

simple-audio-card,dai-link0 {
            /* HDMI */
            format = "i2s";

simple-audio-card,dai-link1 {
            /* DAC */
            format = "i2s";

simple-audio-card,dai-link2 {
            /* SPDIF */
            format = "left_j";

See also below TXT file:

linux-4.19.38/Documentation/devicetree/bindings/sound/st,sti-asoc-card.txt

From AM335x McASP side, these formats impact DAVINCI_MCASP_TXFMCTL_REG and DAVINCI_MCASP_RXFMCTL_REG registers. Make sure you have the correct McASP FMCTL settings for each codec.

linux-4.19.38/sound/soc/ti/davinci-mcasp.c -> davinci_mcasp_set_dai_fmt()

Regards,
Pavel

Pavel,

Right now for my 1st codec TLV320AIC3104, I use dsp_b and I am using following pins for it: MCASP0_ACLKx, MCASP0_FSx, MCASP0_AXR0, MCASP0_AXR2. For my 2nd codec Si3217x which only uses PCM, I will use I2C to receive TDM on the same pins MCASP0_ACLKx, MCASP0_FSx, MCASP0_AXR0, MCASP0_AXR2. This should be good right? Or is my approach wrong?

After reading all the articles and device trees you suggested, I have a device tree now. Please have a look at my partial dts below and let me know if this will work:

sound0: sound@0 {
		compatible = "simple-audio-card";
		simple-audio-card,name = "AM335x-EVM";
		simple-audio-card,widgets =
			"Headphone", "Headphone Jack",
			"Line", "Line Out",
			"Line", "Line In";
		simple-audio-card,routing =
			"Headphone Jack",	"HPLOUT",
			"Headphone Jack",	"HPROUT",
			"LINE1L",		"Line In",
			"LINE1R",		"Line In"
			"Line Out",     "LLOUT",
			"Line Out",     "RLOUT";
		simple-audio-card,dai-link@0 {
			format = "dsp_b";
			bitclock-master = <&sound0_0_master>;
			frame-master = <&sound0_0_master>;
			sound0_0_master: cpu {
				sound-dai = <&mcasp0>;
			};

			codec {
				sound-dai = <&tlv320aic3104>;
				clocks = <&clk_mcasp0>;
				clock-names = "mclk";
			};
		};

		simple-audio-card,dai-link@1 {
			format = "i2s";
			bitclock-master = <&sound0_1_master>;
			frame-master = <&sound0_1_master>;
			sound0_1_master: cpu {
				sound-dai = <&mcasp0>;
			};

			codec {
				sound-dai = <&si3217x>;
				clocks = <&clk_mcasp0>;
				clock-names = "mclk";
			};
		};
	};

&mcasp0 {
	#sound-dai-cells = <0>;

	pinctrl-names = "default";
	pinctrl-0 = <&mcasp0_pins>;

	status = "okay";

	op-mode = <0>;		/* MCASP_IIS_MODE */
	tdm-slots = <2>;
	num-serializer = <16>;
	serial-dir = <	/* 0: INACTIVE, 1: TX, 2: RX */
					2 0 1 0  
					0 0 0 0
					0 0 0 0
					0 0 0 0
	>;
	tx-num-evt = <32>;
	rx-num-evt = <32>;
};

Here I am not sure about "tx-num-evt", "rx-num-evt", and "tdm-slots". Can I use I2S to receive PCM data? Is the device tree ok? Or do I need to make changes?

Thank you,

Samer