Ping - it would be really interesting to know if disabling the kernel driver is simple thing that can be configured from user-space, or maybe if there are alternatives.
So far I enjoyed that it is possible to relatively simply just read the datasheet and set the registers, but that seems to increasingly getting complicated with the kernel doing its own thing. Which is fine I suppose, but is there a documentation how to use the PWM subsystem in that case ? -h On 2 January 2018 at 07:41, Leonardo Romor <[email protected]> wrote: > > Hello, > thank you for the answer and sorry for the late reply, > is it possible to disable the driver without recompiling the kernel? > > I see there are 4 drivers present for the am335x: > > > kernel/drivers/pwm/pwm-tiecap.ko > kernel/drivers/pwm/pwm-tiehrpwm.ko > kernel/drivers/regulator/pwm-regulator.ko > kernel/drivers/video/backlight/pwm_bl.ko > > What's the difference between the first two? > > The folder I assumed to be filled (/sys/class/pwm) when the drivers are > enabled is empty. > > Also: > Does the kernel manages the timer and pwm with same driver? > > Thank you, > > -l > > > Il giorno venerdì 29 dicembre 2017 15:53:28 UTC+1, RobertCNelson ha scritto: >> >> On Fri, Dec 29, 2017 at 8:22 AM, Henner Zeller <[email protected]> wrote: >> > On 27 December 2017 at 13:48, Leonardo Romor <[email protected]> >> > wrote: >> >> Hello, >> >> >> >> could someone explain me why running this code freezes the kernel? >> >> >> >> https://gist.github.com/lromor/e303c88cfb8a065d411f2ba0bc52324b >> > >> > Thanks Leonardo to measure and put together this report of this issue >> > when using 4.4.91-ti-r137. >> > >> >> >> >> It should turn on the beaglebone TIMER4. >> >> I have tested this code on 3.8 kernel and it works. >> > >> > This currently prevents PWM to work in BeagleG in newer kernels; so it >> > would be good to know from some of the people familiar with the >> > kernel/GPIO interaction could chime in and explain what is going on >> > and if there is a way to work-around it or if the initialization >> > should be different altogether. >> >> Let's see, your mmap'ing a clock that "was" being handled by the >> kernel's pwm subsystem, and now the system freezes... >> >> Well, stop mmap'ing or disable the pwm driver.. >> >> Regards, >> >> -- >> Robert Nelson >> https://rcn-ee.com/ > > -- > 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/e93eaf41-49ef-4db1-b7ac-bae099b0dab2%40googlegroups.com. > > 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/CAEQqtJwU7Bj2S3jQWe-zrA3Xs8XhmmXjO9o802NcF9kejdxEmQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
