attached . . .but I figure you all knew that already ;) On Mon, Feb 8, 2016 at 5:13 PM, William Hermans <[email protected]> wrote:
> @Mark, > > Yes,and no. > > No, in that there is no way to differentiate which header the peripheral > is physically attacked to. > > Yes, in that device tree "defines" usually define a device module as > something similar to: > > device_tree_friendly_name@<peripheral module base address> > > In other words, we should be able to extrapolate which device module, and > pins are used based on their base address. There is also a place in a > systems directory structure that sysfs uses the base address as part of the > path for the device . . .but I can not recall exactly where that is :/ > > > On Mon, Feb 8, 2016 at 4:56 PM, Mark A. Yoder <[email protected]> > wrote: > >> Well, they move around depending on which dts you boot under. P9_14 >> appears at /sys/class/pwm/pwmchip*2*/pwm0 with >> *cat $SLOTS * >> 0: PF---- -1 >> 1: PF---- -1 >> 2: PF---- -1 >> 3: PF---- -1 >> 4: P-O-L- 0 Override Board Name,00A0,Override Manuf,*univ-emmc* >> >> But if you use: >> *cat $SLOTS * >> 0: PF---- -1 >> 1: PF---- -1 >> 2: PF---- -1 >> 3: PF---- -1 >> 4: P-O-L- 0 Override Board Name,00A0,Override Manuf,*cape-universaln* >> >> it appears at /sys/class/pwm/pwmchip*4*/pwm0! >> >> Is there a way the pwm system can tell you which headers they are >> attached to? >> >> --Mark >> >> On Monday, February 8, 2016 at 6:42:11 PM UTC-5, RobertCNelson wrote: >>> >>> On Mon, Feb 8, 2016 at 5:36 PM, Mark A. Yoder <[email protected]> >>> wrote: >>> > Well.... /sys/class/pwm/pwmchip2/pwm0 worked! Thanks... >>> > >>> > So given the pin name (P9_14 for example) how do I find the pwm path? >>> (I'm >>> > trying to port bonescript to Jessie.) >>> >>> For the pwm, I think it's load order (scary).... not sure if we can >>> for an alias in the dt.. >>> >>> 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]. >> 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]. For more options, visit https://groups.google.com/d/optout.
