Enabling the am335x-boneblack-prucape.dtsi overlay

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1

I am trying to figure out the how to configure the device tree overlay for the PRU-cape.

I am using the latest recommended image from http://beagleboard.org/latest-images (i.e. Debian 8.3 Linux beaglebone 4.1.15-ti-rt-r43) without any changes.

I uncommented the following line in uEnv.txt because I read that the HDMI interface has to be disabled

##BeagleBone Black: HDMI (Audio/Video)/eMMC disabled:
dtb=am335x-boneblack-overlay.dtb

This is what works:
1.) I can build and load the PRU_LED0.out from TI’s software support package onto PRU0 with remoteproc
2.) Then I use the command “config-pin P9.30 pruout” and the led blinks

But I this only works with this particular pin. I would actually like is to enable all the pins for the PRU that are in defined “am335x-boneblack-prucape.dtsi”. I have tried a myriad things (I don’t really want to list all of them, but if it helps i will).

Can anyone give me a hint on how to enable the overlay?

There seem to be different ways to enable pins i.e. use “config-pin”, loading adding an overlay to “/sys/devices/platform/bone_capemgr/slots”, going to the “/opt/source/dtb-4.1-ti/” directory and changing and making the files there. What is the recommended way?

Should I use a different image?

2

I am trying to figure out the how to configure the device tree overlay for
the PRU-cape.

I am using the latest recommended image from
Latest Software Images - BeagleBoard (i.e. Debian 8.3 Linux beaglebone
4.1.15-ti-rt-r43) without any changes.

I uncommented the following line in uEnv.txt because I read that the HDMI
interface has to be disabled
#beaglebone Black: HDMI (Audio/Video)/eMMC disabled:
dtb=am335x-boneblack-overlay.dtb

This is what works:
1.) I can build and load the PRU_LED0.out from TI's software support package
onto PRU0 with remoteproc
2.) Then I use the command "config-pin P9.30 pruout" and the led blinks

But I this only works with this particular pin. I would actually like is to
enable all the pins for the PRU that are in defined
"am335x-boneblack-prucape.dtsi". I have tried a myriad things (I don't
really want to list all of them, but if it helps i will).

for reference:

https://git.ti.com/pru-software-support-package/pru-software-support-package/trees/dev/pru_cape

(i didn't realize this existed)

Can anyone give me a hint on how to enable the overlay?

Oh that's not an overlay..

Using the "dtb-rebuilder" just add:

#include "am335x-boneblack-prucape.dtsi"

There seem to be different ways to enable pins i.e. use "config-pin",
loading adding an overlay to "/sys/devices/platform/bone_capemgr/slots",
going to the "/opt/source/dtb-4.1-ti/" directory and changing and making the
files there. What is the recommended way?

You do it anyway you want that works..

overlay is best for development,
config-pin is nice if your doing lots of dynamic changes
/opt/source/dtb-4.1-ti/ us nice if you just want to set and forget about it :wink:

Regards,

3

Thank you for the quick response :slight_smile:

Using the “dtb-rebuilder” just add:

#include “am335x-boneblack-prucape.dtsi”

So I added this to the end of am335x-boneblack-overlay.dts and compiled, but now I keep getting the following error:

[ 16.995007] davinci-mcasp 4803c000.mcasp: invalid tdm slots: 0
[ 20.377029] pinctrl-single 44e10800.pinmux: pin 44e1097c.0 already requested by 4819c000.i2c; cannot claim for 4a300000.pruss
[ 20.764537] pinctrl-single 44e10800.pinmux: pin-95 (4a300000.pruss) status -22
[ 21.041264] pinctrl-single 44e10800.pinmux: could not request pin 95 (44e1097c.0) from group pru_cape_bone_pins on device pinctrl-single
[ 21.526351] pruss-rproc 4a300000.pruss: Error applying setting, reverse things back

I assume that I have to somehow deactivate the i2c in some file. Could you give me some idea how to do that or where to look?

4

In your overlay, you can add the following:

fragment@1 {
target = <&I2c2>;
overlay {
status = “disabled”;
}
}

Regards,
John

5

also make sure in /boot/uEnv.txt

that cape_universal=enable is no longer enabled..

Regards,

6

Wow, I think it works. Thanks a bunch :slight_smile:

This is what I did.

In uEnv.txt:
1.) Uncomment “dtb=am335x-boneblack-overlay.dtb”
2.) change the line: “cmdline=coherent_pool=1M quiet cape_universal=disable” (from enable to disable cape)

Inside /opt/source you’ll find the dtb-rebuilder. It should already be there, but I cloned the latest one directly from Robert’s github https://github.com/RobertCNelson/dtb-rebuilder.git

Inside /opt/source/dtb-rebuilder/src/arm
1.) open: am335x-boneblack-overlay.dts and add the following at the end of the file:

&i2c2 {
status = “disabled”;

};
#include “pru_cape-am335x-boneblack-prucape.dtsi”

2.) Get the file “pru_cape-am335x-boneblack-prucape.dtsi” from https://git.ti.com/pru-software-support-package/pru-software-support-package/trees/dev/pru_cape and copy it into the same directory

3.) make
4.) make install
5.) reboot
6.) be amazed :slight_smile:

7

I followed all the steps explained by lucas. But at make it is saying that there are no targets specified. which one should i specify?