eibinger

I checked this with kernel version 5.10 and the result is the same as with kernel 6.0. I can use the kernel driver i2c-gpio on other gpio pins (for instance 37 and 40) but not on pins 3 and 5. I attached the overlay which worked for pins 37 and 40, the lines with 3 and 5 are commented out. i2c-xx-gpio.dts

i2c-ao-gpio.dtsThat is the overlay I used to activate i2c with bitbang over linux kernel. I also tried to only disable the uart on ao and it was possible to switch the two pins with gpioset. So I think it should be possible to use i2c with a userland driver that works directly with the two pins. Still it is not possible to use software bitbang driver from the kernel. I tested this on two other pins and it worked.

@Da XueThank you for your answer. I finally was able to enable gpio-bitbang for the pins 3 and 5 by the linux i2c-gpio driver. Still it does not work. I can use this software i2c on any gpio pins but not on these two. I also tried to deactivate the serial@4c0 by writing an overlay with status="disabled" for this device to free these pins - still no luck. Is there a way to disable the uart on pins 3+5 and use them as gpio pins?