On 3/3/2018 10:59 PM, John Morris wrote: > > Instead, I compile and install a .dts file with just the wanted pins, > and add the line > `uboot_overlay_addr0=/lib/firmware/bb_autoclave-00A0.dtbo` to > `/boot/uEnv.txt`. This doesn't seem to assign any pins, but I'm > unclear whether it's a bad file or something else. > > https://github.com/zultron/autoclave_control/blob/master/etc/bb_autoclave.dts
That snippit of a device tree overlay is incomplete. I suggest you start with one of the unviersal overlays and chop out everything you don't need. Alternately, add some more stuff to your minimal overlay file. Using your first pin (P9_18) as an example: You first need to define some pin mux settings (note you only need to define the ones you want to use): target = <&am33xx_pinmux>; https://github.com/cdsteinkuehler/beaglebone-universal-io/blob/master/cape-universal-00A0.dts#L479-L495 ...then you can setup the pinmux helper: target = <&ocp>; compatible = "bone-pinmux-helper"; https://github.com/cdsteinkuehler/beaglebone-universal-io/blob/master/cape-universal-00A0.dts#L1040-L1052 These two bits are the "magic" that lets you play with pinmux settings from user space. To change the default pin settings, either edit the default value directly (ie: P9_18_default_pin) or change the first entry in the pinmux-helper stanza, ie: // pinctrl-0 = <&P9_18_default_pin>; pinctrl-0 = <&P9_18_gpio_pd_pin>; Finally, export the gpio pins, this is what makes them visible in sysfs and is basically the same as: "cat $pin > /sys/class/gpio/export": target = <&ocp>; compatible = "gpio-of-helper"; https://github.com/cdsteinkuehler/beaglebone-universal-io/blob/master/cape-universal-00A0.dts#L1408-L1413 Or as mentioned previously, if you don't need to mess with the pinmux settings you can just export the GPIO pins you need via the sysfs interface. -- 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.
