Could not find symbol mcasp0_pins

Hello all,

When trying to apply the Device tree overlay below, I get the error mentioned in the subject above. This was taken from a pre-existing overlay but perhaps the lastest Debian image calls it something else. Before anyone mentions the commented line at the bottom of the overlay I’m trying two variations one with the line commented the other without the line commented. Both yield the same error in dmesg.

Here’s the image I am using:

Debian Image 2015-11-03 for BeagleBone Black

Thanks in advanced for any asistance provided.

Best Regards,
Jorge Garcia

/* Copyright © 2012 Texas Instruments Incorporated - http://www.ti.com/

I apologize I think I accidentally posted this in multiple places, sorry.

I was reading on various device tree topics last week, and seem to recall the most well known cause for this complaint from dtc is: You have the wrong device tree compiler.

So, what is the output of
dtc --version

?

Additionally, searching through my own de-compiled am335x-boneblack.dtb board file. mcasp0_pins does not exist.

`
william@ds64:~/ramfs/bb-kernel/KERNEL/arch/arm/boot/dts$ git grep -inIE --color=ALWAYS “mcasp0_pins”
. . .
am335x-cape-bbb-exp-c.dtsi:63: mcasp0_pins: pinmux_mcasp0_pins {
am335x-cape-bbb-exp-c.dtsi:113: pinctrl-0 = <&mcasp0_pins>;
am335x-cape-bbb-exp-r.dtsi:56: mcasp0_pins: pinmux_mcasp0_pins {
am335x-cape-bbb-exp-r.dtsi:92: pinctrl-0 = <&mcasp0_pins>;
. . .

`

So, I have not looked into either of these device tree include files . . . However if you include one of these, or copy the mcasp0_pins or if you copy this definition section from one of those file, into your device tree overlay. The problem should be fixed. Of course, it would behoove you to make sure the pinmux / pins are correct for your situation . . .

DTC 1.4.0

`
william@ds64:~/ramfs/bb-kernel/KERNEL/arch/arm/boot/dts$ git grep -inIE --color=ALWAYS “mcasp0_pins”
. . .
am335x-cape-bbb-exp-c.dtsi:63: mcasp0_pins: pinmux_mcasp0_pins {
am335x-cape-bbb-exp-c.dtsi:113: pinctrl-0 = <&mcasp0_pins>;
am335x-cape-bbb-exp-r.dtsi:56: mcasp0_pins: pinmux_mcasp0_pins {
am335x-cape-bbb-exp-r.dtsi:92: pinctrl-0 = <&mcasp0_pins>;
. . .

`

So, I have not looked into either of these device tree include files . . . However if you include one of these, or copy the mcasp0_pins or if you copy this definition section from one of those file, into your device tree overlay. The problem should be fixed. Of course, it would behoove you to make sure the pinmux / pins are correct for your situation . . .

Hi William,

Thank you for taking the time to respond, I really appreciate it. My endgoal here is to re-enable the default HDMI audio because the LCD cape I’m using disables it. That’s what got me into this whole mess in the first place.

These files that you are referencing are not on the BBB itself, correct? Would it be as simple as adding an include statement to my overlay? I would obviously confirm that the pins are muxed properly.

Thanks again for your help.

Best Regards,
Jorge Garcia

Ok, I jumped the gun on that answer. I assumed that you had that alias in place, but apparently you do not. That alias is not included in the stock board device tree file.

These files that you are referencing are not on the BBB itself, correct? Would it be as simple as adding an include statement to my overlay? I would obviously confirm that the pins are muxed properly.

It could be yes, but you’ll have to double check everything. You’re very likely to have conflicts between overlays with stock settings.

DO also keep in mind that I’m not an expert with device tree files, and am still learning myself. But this sort of thing is what I’ve learned in the last couple weeks . . .

So, *.dtsi files, are device tree source include files . . .

Or just add them in your overlay..

https://github.com/beagleboard/linux/blob/3.8/firmware/capes/cape-boneblack-hdmi-00A0.dts#L82-L90

Regards,

Or just add them in your overlay…

https://github.com/beagleboard/linux/blob/3.8/firmware/capes/cape-boneblack-hdmi-00A0.dts#L82-L90

Regards,

Robert Nelson
https://rcn-ee.com/

Hi Robert,

Thank you for taking the time to respond to me. Looking at that example, I’m correct in thinking that I should add an additional fragment to my overlay that targets am33x-pinmux and include the lines you mentioned?

If that’s the case then I think I got it.

Best Regards,
Jorge Garcia

Hi Robert,

Thank you for taking the time to respond to me. Looking at that example, I'm
correct in thinking that I should add an additional fragment to my overlay
that targets am33x-pinmux and include the lines you mentioned?

If that's the case then I think I got it.

Yeap, you can target am33x-pinmux and add all the aditional pinmux you need.

Regards,

THANK YOU!!!

I was final able to get an overlay that brought back HDMI audio, without invoking HDMI video. I have attached it in case anyone else needs it.

Let me know if there’s a better place to put this.

Best Regards,
Jorge Garcia

jorge-audio-cape-normal.dts (2.25 KB)