Hi everyone,
I’m trying to add at least three additional GPIO chip selects in addition to the existing hardware CS for SPI0. I found a tutorial here: https://dev.iachieved.it/iachievedit/gpio-chip-selects-with-the-beaglebone/ However, I’m trying to get this to work with the latest U-boot overlays. I’ve modified the device tree file, compiled it, added it to /boot/uEnv.txt under uboot_overlay_addr4. However, I’m getting this error on boot:
[ 1.565570] pinctrl-single 44e10800.pinmux: pin PIN84 already requested by ocp:P9_22_pinmux; cannot claim for 48030000.spi
[ 1.576764] pinctrl-single 44e10800.pinmux: pin-84 (48030000.spi) status -22
[ 1.583861] pinctrl-single 44e10800.pinmux: could not request pin 84 (PIN84) from group pinmux_bb_spi0_pins on device pinctrl-single
[ 1.595922] omap2_mcspi 48030000.spi: Error applying setting, reverse things back
[ 1.603527] omap2_mcspi: probe of 48030000.spi failed with error -22
Based on my understanding, it looks like the universal cape overlay has already claimed the pins, and I’m now unable to set my own settings for the pin. Is there any way around this without decompiling / editing the universal cape overlay? Are there any guides on how to do this with uboot overlays? Unfortunately almost all the documentation revolving device trees on Beaglebone still revolve around the old slots architecture, and very little documentation is available for uboot overlays.