You are correct...you error is at a lower level than config-pin. The problem is the mode you want is not implemented by the universal overlay:
https://github.com/RobertCNelson/bb.org-overlays/blob/master/src/arm/cape-universal-00A0.dts#L1551-L1562 You can either request an update to the universal overlay, patch it and send a PR, or migrate to using a "real" device-tree overlay. When I created the "Universal" overlay, I didn't expect many people to be trying to use the General Purpose Memory Controller. ;-) On 4/19/2019 3:08 PM, Jeff Pollard wrote: > Hi, > That makes sense, but.... > > I can use config-pin to set the value to something like: > * pwm* > for example: > * config-pin P8.14 pwm* > will work just fine > as will *gpio* > and > *gpio_pd, etc.* > > But, *gpmc* (mode 0) is not a valid choice i.e. config-pin p8.14 gpmc is > invalid > I tried adding it to the config-pin script for pin 8_14, but that didn't > help as it appears the problem is deeper than than. I can't change the > value of state in: > > /sys/devices/platform/ocp/ocp:P8_14_pinmux/state > > the error I get is: > > *Cannot write pinmux File: /sys/devices/platform/ocp/ocp:P8_14_pinmux/state* > > Jeff > > On Friday, April 19, 2019 at 12:39:21 PM UTC-7, Mala Dies wrote: >> >> Hello, >> >> The config-pin utility can be used in user land or user land w/ a .sh >> script and .service file to boot the board w/ the required config-pin >> utility being present. >> >> Seth >> >> P.S. If you know how to do this instead, this may work for you. So, use: >> config-pin P8.14 <mode> <--- this would be your mode, i.e. GPIO, UART, and >> etc. >> >> So, if you wanted to put in gpio in <mode>, you could if this is what you >> want. Does this sort of make sense? >> >> On Friday, April 19, 2019 at 1:55:21 PM UTC-5, Jeff Pollard wrote: >>> >>> >>> Hi, >>> >>> I'm using:* Linux beaglebone 4.14.106-bone-rt-r19 #1 PREEMPT RT Tue >>> Mar 26 19:02:06 UTC 2019 armv7l GNU/Linux* >>> >>> I started by disabling the emmc in uEnv.txt >>> >>> I then tried to modify the config-pin script for P8_14 (which would be >>> gpmc_AD14 as a starting example), but I get >>> >>> *Cannot write pinmux File: >>> /sys/devices/platform/ocp/ocp:P8_14_pinmux/state* >>> >>> Can anyone give a pointer on how to go about configuring pins to use >>> gmpc mode with the config-pin script (or any other method)? >>> >>> Thanks, >>> >>> Jeff >>> >> > -- Charles Steinkuehler [email protected] -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
