Am Sa., 6. Juli 2019 um 07:08 Uhr schrieb TJF <[email protected]>:
> I said: > > AFAIR the PRU cannot write to PWMSS-0 SS when the tbclk isn't enabled. >> > > That's wrong, sorry. > No problem :-) > > Am Samstag, 6. Juli 2019 02:24:02 UTC+2 schrieb Super Duper88: >> >> I had also the idea to enable clock for PWMSS2 via enabling control >> module bit. >> But writing to "pwmss_ctrl Register" 0x44E10664 didn't change behaviour. >> > > How do you write? The PRU has no write access to that adress (just fails, > no message). It needs the ARM in supervisor mode (kernel module). > You are completely right. After some reading, I found that in AM335x TRM: Note: For writing to the control module registers, the MPU will need to be in privileged mode of operation and writes will not work from user mode. I assumed if PRU has access to global memory, I could write everywhere but that's obviously wrong. Also thanks for the link to libpruio. Impressive work! All in all getting PWMSS to work in 4.x was a much harder than expected. Hopefully usage of SPI is less complicated... Grüße aus Erfurt Best regards > >> >> Maybe I have to write also to "CM_PER_EPWMSS2_CLKCTRL Register" at >> 0x44E000D8? >> > > Sure, this reg must contain the value 2. The PRU can write. > > Regards > > PS: You could use the loadable kernel module from libpruio to fix this > issue. First, it enables all PWM module clocks [0-2] (like in 3.8 kernel). > And later you can adapt the setting via sysfs (to synchonize PWM modules). > Just install the libpruio-lkm package from Arends PPA. Find details at > > > http://users.freebasic-portal.de/tjf/Projekte/libpruio/doc/html/ChaPreparation.html#SecDebPac > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/Ia2OC_8wArE/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/18b83539-f70a-457a-b54b-2d85a3f0f6d8%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/18b83539-f70a-457a-b54b-2d85a3f0f6d8%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAG%2BFkwF7SvvpirbivSdZm2n_Wkoa2NAUw_gY_dz19aFfcHUgDA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
