So a few things to note about pwm behavior on the latest stretch image versus Jessie. Obviously, Jessie by default runs an older kernel. 4.4.x versus 4.9.x.
First, Jessie: root@wgd:~# uname -r 4.4.68-ti-r111 root@wgd:~# lsmod |grep pwm pwm_tiehrpwm Stretch: root@wgd:~# uname -r 4.9.50-ti-r61 root@wgd:~# lsmod |grep pwm /* No output */ Here, I'm thinking the PWM module is built into the kernel. Because I'm running the same custom overlay on both boards, and both have a populated sysfs entry for pwm. However there is a difference. Jessie: root@wgd:~# ls /sys/class/pwm/pwmchip0 device export npwm power pwm0 pwm1 subsystem uevent unexport Stretch: root@wgd:~# ls /sys/class/pwm/pwmchip0 device export npwm power pwm0 subsystem uevent unexport Here, initially, there was no pwm0 substructure. This populated after I ran echo '0' > /sys/class/pwm/pwmchip0/export as root. Further examination seems to indicate that pwm0 channel A is fully functional. root@wgd:~# ls /sys/class/pwm/pwmchip0/pwm0/ capture duty_cycle enable period polarity power uevent But I have not physically tested the hardware just yet. So my questions are this. What's the difference ? Does this have something to do with the module being built into the kernel. or is there some kind of overlay change I'm not currrently aware of ? config-pin for my project here is not an option . . . And in fact, cape_universal is disabled via the uboot envrorinment file. Everything else seems to be exactly the same as far as I can tell, but I have not poured over the whole system just yet. Seems to be pretty stable too, but I've only been running the latest console stretch image for a few days now. -- 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 beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/04056bac-16ec-4bba-b0c7-453df7efd228%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
