Hi Don!

Am Sonntag, 3. März 2019 13:49:12 UTC+1 schrieb Don Pancoe:
>
> I am trying the *pwm_cap* example but am getting the following error:
> sudo ./pwm_cap
> failed setting input @P_IN (pin P9_42 claimed by: ocp:P9_42_pinmux)
>
> I am running 4.14 and have installed from the Debian packages, including 
> *libpruio*, *libpruio-dev* and *libpruio-lkm*. I have made the following 
> changes to *uEnv.txt*...
>
>    - enable_uboot_cape_universal=0
>    - uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo
>    
> What else might I be missing? Thank you for the help.
>

That's a uBoot issue. Although you configured in file /boot/uEnv.txt the 
variable enable_uboot_cape_universal=0, the cape universal stuff gets 
loaded and claims all free pins. By default libpruio respects these claims. 
You can either

   1. call the constructor with bit PRUIO_ACT_FREMUX set, in order to 
   activate free pinmuxing (note: in this case libpruio can override the 
   pinmux modes of all CPU balls, so it's a quick and dirty, and also 
   dangerous solution), or
   2. help uBoot to do its work by renaming (or removing) the device tree 
   blob that triggers the cape universal stuff (*/**boot/dtbs/*`uname 
   -r`/am335x-boneblack-uboot-univ.dtb).

I recommend the second solution, since it makes (nearly) all pins free for 
libpruio, and also saves a lot of kernel memory (the blob is > 150 kB), as 
well as speeds up the boot process. (Note: pins P9_19 and P9_20 will still 
be claimed.)

Regards

PS: When you copy the example sources to your home directory and add 
yourself to the user gruop pruio, you can work from user space (no admin 
privileges necessar = omit sudo).

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