On Wed, Sep 27, 2017 at 1:31 PM, Robert Nelson <[email protected]> wrote:
> > Don't compare "pwmchipX's" directly, you need to dig into the symlink: > > root@beaglebone:/sys/class/pwm# ls -lh > total 0 > lrwxrwxrwx 1 root root 0 Oct 13 17:14 pwmchip0 -> > ../../devices/platform/ocp/48300000.epwmss/48300200.pwm/pwm/pwmchip0 > lrwxrwxrwx 1 root root 0 Oct 13 17:14 pwmchip2 -> > ../../devices/platform/ocp/48300000.epwmss/48300100.ecap/pwm/pwmchip2 > lrwxrwxrwx 1 root root 0 Oct 13 17:14 pwmchip3 -> > ../../devices/platform/ocp/48302000.epwmss/48302200.pwm/pwm/pwmchip3 > lrwxrwxrwx 1 root root 0 Oct 13 17:14 pwmchip5 -> > ../../devices/platform/ocp/48304000.epwmss/48304200.pwm/pwm/pwmchip5 > lrwxrwxrwx 1 root root 0 Oct 13 17:14 pwmchip7 -> > ../../devices/platform/ocp/48304000.epwmss/48304100.ecap/pwm/pwmchip7 > > https://github.com/RobertCNelson/bb.org-overlays/ > blob/master/examples/cape-unversal-pwm.txt#L3-L9 > > Regards, > So I get what you're saying, and get what the link is stating as well. However, I'm not seeing how the pwmchipX value is changing at all. More to the point, I really do not care if the underlying path changes, so long as I do not have to completely rewrite a library in order to use the sysfs pwm objects. Moreover, what good is loading a uboot overlay, if that overlay does not do what it is supposed to do ? It would be really nice to have the pwm channels functioning before the OS is loaded. *Jessie:* root@wgd:~# ls -lh /sys/class/pwm total 0 lrwxrwxrwx 1 root pwm 0 Sep 24 19:18 pwmchip0 -> ../../devices/platform/ocp/48300000.epwmss/48300200.pwm/pwm/pwmchip0 lrwxrwxrwx 1 root pwm 0 Sep 24 19:18 pwmchip2 -> ../../devices/platform/ocp/48302000.epwmss/48302200.pwm/pwm/pwmchip2 lrwxrwxrwx 1 root pwm 0 Sep 24 19:18 pwmchip4 -> ../../devices/platform/ocp/48304000.epwmss/48304200.pwm/pwm/pwmchip4 *Stretch:* root@wgd:~# ls -lh /sys/class/pwm total 0 lrwxrwxrwx 1 root pwm 0 Sep 26 21:20 pwmchip0 -> ../../devices/platform/ocp/48300000.epwmss/48300200.pwm/pwm/pwmchip0 lrwxrwxrwx 1 root pwm 0 Sep 26 21:20 pwmchip2 -> ../../devices/platform/ocp/48302000.epwmss/48302200.pwm/pwm/pwmchip2 lrwxrwxrwx 1 root pwm 0 Sep 26 21:20 pwmchip4 -> ../../devices/platform/ocp/48304000.epwmss/48304200.pwm/pwm/pwmchip4 Seriously, I can run a script at boot, then run all the echo's I need in order to populate the entire pwm subsystem for each "duel channel" pwm chip I need to use. But it was my hope I did not have to. With all of that said, this structure is all I care about. root@wgd:~# uname -r 4.4.68-ti-r111 root@wgd:~# ls /sys/class/pwm/pwmchip*/ |grep pwm /sys/class/pwm/pwmchip0/: npwm pwm0 pwm1 /sys/class/pwm/pwmchip2/: npwm pwm0 pwm1 /sys/class/pwm/pwmchip4/: npwm pwm0 pwm1 I would like Stretch to be the same at boot, without the need to run a script if possible. But it's not. root@wgd:~# uname -r 4.9.50-ti-r61 root@wgd:~# ls /sys/class/pwm/pwmchip*/ |grep pwm /sys/class/pwm/pwmchip0/: npwm pwm0 /sys/class/pwm/pwmchip2/: npwm /sys/class/pwm/pwmchip4/: npwm Did I miss something in what you were saying ? -- 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/CALHSORriCEUtbgw9jExKFeh_ofuvDqEwCyf5Je7So-%2BWoGgcCg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
