AM625: McASP configuration - GPIO Mux

Darren

I you asking about the pinmux (padconfig) configuration using SysConfig or configuring the SDK?

If pinmux, can you elaborate on GPIO Multiplexer?  The SysConfig pinmux has specific McASP peripherals in the left menu and then selectable use cases.

The above will create the following devicetree.dtsi

/* This file was auto-generated by TI PinMux on 4/28/2023 at 8:50:44 AM. */
/* This file should only be used as a reference. Some pins/peripherals, */
/* depending on your use case, may need additional configuration. */

&main_pmx0 {
	mymcasp1_pins_default: mymcasp1-pins-default {
		pinctrl-single,pins = <
			AM62X_IOPAD(0x0090, PIN_INPUT, 2) /* (K17) GPMC0_BE0n_CLE.MCASP1_ACLKX */
			AM62X_IOPAD(0x0098, PIN_INPUT, 2) /* (P21) GPMC0_WAIT0.MCASP1_AFSX */
			AM62X_IOPAD(0x008c, PIN_INPUT, 2) /* (J17) GPMC0_WEn.MCASP1_AXR0 */
		>;
	};
};

We need more detail in order to help. 

--Paul

Hi Paul,

From the customer:

To clarify, I am trying to use the McASP through the GPIO pins instead of through the 3.5mm jack, which seems to be the factory u-boot configuration. I was able to add a McASP device on SysConfig, but I was confused since SysConfig did not show me the other peripherals (MMC, SPI, UART, etc.) when I opened the .syscfg file provided with the EVM SDK -- is this normal? All pins appear to be unassigned when I open the .syscfg file.

Looking at the screenshot from the post, I also don't see the "Use Case" and the "Pull Up/Down" sections on my SysConfig. I am using SysConfig version 1.16.1+2960, which seems to be the latest. I am using the Linux version on Ubuntu 18. I have the SDK version 08.06.00.42 for the AM62xx EVM, which seems to be the latest as well. You can find a screenshot of SysConfig attached, note the sections that are there on the forum post but not on my end. I am using Keystone3 Resource Partition Tool 0.5. through SysConfig.

I am also unsure as to how SysConfig generates the .dts files. the "Generated files" section only contains .c and .h files, how can I get the u-boot configuration from these? You can see the files on the screenshot attached.

I noticed the customer is using Linux RT based on the screen shot.  Is that an important factor?

Thanks,

Darren

This looks to me that the customer is using the SDK product, not the base pinmux tool 

Darren Jenkins said:

To clarify, I am trying to use the McASP through the GPIO pins instead of through the 3.5mm jack

I assume they are referring to the SK-AM62 and want to use the MCASP1 functionality on header pins rather than  driving the TLV320AIC3106/SIL9022A .

I do not see where they would be able to access any McASP via a header. 

Can you get  more detail on where they expect to connect to the MCASP? 

--Paul 

Thanks Paul.

More from the customer:

The download page for PinMux tells me that PinMux is deprecated in favor of SysConfig, should I use PinMux anyways?

The datasheet suggests that some of the McASP's are accessible via the 40-pin expansion header and the PRU HDR, and the pins seem to be multiplexed with other I/O. I am trying to figure out how to tell the McASP to use these pins instead of the defaults, and tell the multiplexer to route these pins to the McASP via u-boot.

Thanks,

Darren

Darren 

It is true that J3 does have some of the McASP signals available. I have summarized them here:

I have highlighted the word and bit clock signals.  However, you can see that none of the options have both a ACLKX and AFSX necessary to send data to a codec or work in asynchronous  mode.

Both McASP0 and McASP1 have both ACLKR and AFSR, which would allow them to operate as receivers.  Note: all of the serializers listed for an instance may not be available due to IOSets. The SySconfig tool must be used to validate any pin combinations are in thje sam3e IOSet. . 

Darren Jenkins said:

The download page for PinMux tells me that PinMux is deprecated in favor of SysConfig, should I use PinMux anyways?

No, use the Sysconfig Pinmux,

However, the SysConfig pinmux will only configure the SoC muxing, it will not configure the EVM settings. I am not aware if this would be supported by the SysConfig SDK tool. . 

If the limited McASP config is acceptable, then it will need to be determined if the signal can actually be used, or isolated, as a McASP signal by review the signal connectivity in the EVM schematic. 

-- Paul 

Hi Paul,

Thanks for the help with this.

Customer response:

The limited configuration covers what we need for testing. We are trying to receive an TDM2 stream from McASP0, which can receive from the GPIO as you have pointed out.

"However, the SysConfig pinmux will only configure the SoC muxing, it will not configure the EVM settings" In that case, what should I use to configure the EVM to mux McASP0 RX through J3?

Thanks,

Darren

Hi Paul,

Thank you for all the help.  This is good.  Problem solved.

Darren