P9_12 not available for cape universal with DLP cape mounted

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1

Hello,

I try to access GPIO on pin P9_12 from python script using Adafruit_GPIO package, the pin is not available for use. Python script complains about missing file:

ValueError: Set gpio mode failed, missing file or invalid permissions.

config-pin does not see it either:

$ sudo config-pin P9_12 gpio
P9_12 pinmux file not found!
bash: /sys/devices/platform/ocp/ocpP9_12_pinmux/state: No such file or directory
Cannot write pinmux file: /sys/devices/platform/ocp/ocpP9_12_pinmux/state

What works is exporting GPIO 60 through sys fs, and reading its value from /sys/class/gpio/gpio60/value

With cape removed python script and config-pin work as expected. According to the documentation, the cape does not use this GPIO, so it should not be reserved.

Here’s output from version.sh:
$ sudo /opt/scripts/tools/version.sh
git:/opt/scripts/:[e307a944e0be0610ff5296e0abe4ad31a6e70daa]
eeprom:[A335BNLTBWA51645BBWG0580]
model:[TI_AM335x_BeagleBone_Black_Wireless]
dogtag:[BeagleBoard.org Debian Image 2017-08-01]
bootloader:[eMMC-(default)]:[/dev/mmcblk1]:[U-Boot 2017.07-00002-g61c3ee0fb5]:[location: dd MBR]
kernel:[4.14.21-bone-rt-r13]
nodejs:[v4.8.7]
uboot_overlay_options:[enable_uboot_overlays=1]
uboot_overlay_options:[uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-4-TI-00A0.dtbo]
uboot_overlay_options:[enable_uboot_cape_universal=1]
pkg:[bb-cape-overlays]:[4.4.20180223.0-0rcnee0~jessie+20180223]
pkg:[bb-wl18xx-firmware]:[1.20170829-0rcnee2~jessie+20180104]
pkg:[firmware-ti-connectivity]:[20170823-1rcnee0~jessie+20170830]
groups:[debian : debian adm kmem dialout cdrom floppy audio dip video plugdev users systemd-journal netdev i2c bluetooth cloud9ide gpio pwm admin spi tisdk weston-launch xenomai]
cmdline:[console=ttyO0,115200n8 bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk1p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 quiet]
dmesg | grep pinctrl-single
[ 0.889759] pinctrl-single 44e10800.pinmux: 142 pins at pa f9e10800 size 568
dmesg | grep gpio-of-helper
[ 0.890749] gpio-of-helper ocp:cape-universal: ready
END

Regards,

Jacek.

2

Posting for future reference: libgpiod and python bindings work great, and do not rely on the problematic sysfs support.

Jacek.

3

I’ve been working on this issue these last few weeks, but with embedded world conference this week I haven’t worked on it. I should have more things lined up starting right before elc portand.

Regards,

4

Thanks for taking care of it!

Jacek.

5

Hello,

I just wanted to tell you that I am encountering a similar issue, maybe the description of it can help.
I wanted to use UART4 to send information to an Xbee radio, I am enabling it by loading the 3BB-UART2-00A0.dtbo3 in uEnv.txt :

###Master Enable
enable_uboot_overlays=1

6

uart2 or uart4?

config-pin P9_21 uart
config-pin P9_22 uart

uart4:
config-pin P9_13 uart
config-pin P9_11 uart

Regards,

7

UART4 sorry for the typo, I am loading BB-UART4-00A0.dtbo not the UART2 one.
The config-pin solution is working thanks a lot!!
However, do you know why it is not working with the device tree? I would like to understand the problem

It seems that when I load a device tree it prevents somehow the execution of “gpio-of-helper ocp:cape-universal”, preventing the “ocp:PIN_pinmux” folders to be created in /sys/devices/platform/ocp; am I right?

Thanks,

Pierrick

8

Oh, i've been working on a solution over the last few weeks..

It's just not 100% tested/ready yet..

https://github.com/beagleboard/bb.org-overlays/commits/master

"universal rewrite".

Lots of capes still to test and fix..

Regards,