[Solved]Enabling am335x tmp275

[tomzooi]

Hello all,

I've got a BBB here and I'm trying to read the CPU Temperature. From here it should be available somewhere like /sys/class/hwmon/hwmon0/device/temp1_input (at least in debian). On Arch it is not unfortunately, so after some digging I found that it is probable that is has to do with the device tree missing an entry for the tmp275.

I attempted to fix this by downloading the beagleboard linux devicetree from here compile that and replace the boot am335x-emv.dtb with the newly compiled version and reboot.

Unfortunately I could not compile that device tree since I kept ketting
$this->bbcode_second_pass_code('', '
dtc -I dts -O dtb -o am335x-evm.dtb -b 0 -@ am335x-evm.dts
Error: am335x-evm.dts:10.1-9 syntax error
FATAL ERROR: Unable to parse input tree
')
even with a newer dtc version.

And this is why I am turning to you, to ask how to proceed if I want to read the CPU temperature of my beaglebone. Should I write a device tree overlay or something like here? or is it still possible to recompile the am335x-evm.dts to use the beaglebone device tree?

I also tried to find the original dts devicetree from which archlinuxarm is compiled to see if I could patch that one up and recompile them to get a working am335x-evm.dtb, but I had no luck in locating these unfortunately.

Last point: if this is not the appropriate forum, please move, because I have no clue where this belongs.

//edit:
btw, this is the version: 3.8.13-31-ARCH

[tomzooi]

Using This post I found out that just compiling the Robert C Nelson's dtb-rebuilder using the instructions from here without modifying any files and then copying the newly created am335x-emv.dtb to replace the old one in /boot/dtbs/ It all worked (found the temperature sensor under /sys/class/hwmon/hwmon0/device/temp1_input as expected).

I still have some questions though
- can this be added to the new arch update or something?
- where can I find the original am335x-emv.dts , patch it and compile it with dtc? (since I have not yet found where archlinuxarm gets the "original" dts files from)