I would like to use as many GPIO pins as possible on a Beaglebone black board. I use the latest 4.14 image. I am not using HDMI, wireless, but I do need wired Ethernet and EMMC. So I have my uEnv.txt as below:
###Debug: disable uboot autoload of Cape #disable_uboot_overlay_addr0=1 #disable_uboot_overlay_addr1=1 #disable_uboot_overlay_addr2=1 #disable_uboot_overlay_addr3=1 ### ###U-Boot fdt tweaks... (60000 = 384KB) #uboot_fdt_buffer=0x60000 ###U-Boot Overlays### cmdline=coherent_pool=1M net.ifnames=0 quiet #In the event of edid real failures, uncomment this next line: #cmdline=coherent_pool=1M net.ifnames=0 quiet video=HDMI-A-1:1024x768@60e #Use an overlayfs on top of a read-only root filesystem: #cmdline=coherent_pool=1M net.ifnames=0 quiet overlayroot=tmpfs ##enable Generic eMMC Flasher: ##make sure, these tools are installed: dosfstools rsync #cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh With this configuration, I checked pinmux file @ /sys/kernel/debug/pinctrl/44e10800.pinmux/pinmux-pins, I see pin66-80 are configured to Ethernet pin 66 (PIN66): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 67 (PIN67): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 68 (PIN68): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 69 (PIN69): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 70 (PIN70): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 71 (PIN71): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 72 (PIN72): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 73 (PIN73): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 74 (PIN74): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 75 (PIN75): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 76 (PIN76): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 77 (PIN77): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 78 (PIN78): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 79 (PIN79): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default pin 80 (PIN80): 4a100000.ethernet (GPIO UNCLAIMED) function cpsw_default group cpsw_default My 1st question is: Does this mean all these pins (pin66-80) are not usable for GPIO? They occupy quite a few GPIO pins on P8. Is there a way to reclaim these pins for GPIO use while not affecting Ethernet? My 2nd question is: If later I disable EMMC and only use flash, then will I be able to use most GPIO pins? Thanks. -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/e839a1c0-0bc2-459e-b3c0-0ba4bff7d814%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
