I really just use the cape-universal. I use the /sys stuff to export the pin as pwm. I also use the sysfs interface to setup initial PWM values (period/duty_cycle/enable) and after that, the PRU seems to be able to manipulate the PWM registers to change the dutyscycles and such as needed.
Dan On Sunday, June 30, 2019 at 7:56:45 AM UTC-4, Super Duper88 wrote: > > Hi Daniel, > > thanks for reply. Which kernel and overlay do you use? > How do you enable the PWM pins using PWM devices? > Usually I configure the pins in a overlay. > > On Kernel 3.8 and 4.1 it seems to work. But on 4.9 and 4.14 PRU can't > access PWMSS. > > Best regards > > Am So., 30. Juni 2019 um 02:57 Uhr schrieb Daniel Kulp <[email protected] > <javascript:>>: > >> >> I wasn't able to get access to the PWM registers from the ARM side (same >> bus error), but the PRU can still access them fine. For what I was doing >> a few weeks ago, I used the normal linux PWM devices to enable the PWM pin, >> but then used the PRU to configure the registers and such. Seemed to work >> OK. >> >> Dan >> >> >> >> On Saturday, June 29, 2019 at 4:23:14 PM UTC-4, [email protected] wrote: >>> >>> >>> Hi, >>> >>> during change from 3.8 kernel to 4.14 I struggled with an issue >>> regarding PWMSS accessed by PRU. >>> On old kernel I load overlay am33xx_pwm to activate the PWMSS. >>> I verified this with: devmem2 0x483000000 (base address of PWMSS0) >>> >>> With 4.14 kernel I get 'bus error' when I execute same 'devmem2 >>> 0x483000000' >>> Also PRU have no access to PWMSS. >>> >>> But loading the am33xx_pwm seems succesful, at least the sysfs folder is >>> populated with pwm folders. >>> >>> How can the PRU gain access to PWMSS? >>> >>> Best regards >>> >> -- >> 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] <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/e0bc70ce-afab-491d-b716-c742df377b7c%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/e0bc70ce-afab-491d-b716-c742df377b7c%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/7619f2ca-d1d4-4ef7-9e8f-42b4caa20383%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
