On Mittwoch, 5. September 2018 13:01:26 CEST Volker Kuhlmann wrote: > On Wed 05 Sep 2018 21:06:28 NZST +1200, Alexander Graf wrote: > > rpi:~ # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > > pin 4 (gpio4) function gpio_in in hi; irq 83 (none) > > rpi:~ # echo $(( 458 + 4 )) > /sys/class/gpio/export > > rpi:~ # echo out > /sys/class/gpio/gpio462/direction > > rpi:~ # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > > pin 4 (gpio4) function gpio_out in lo; irq 83 (none) > > rpi:~ # echo 1 > /sys/class/gpio/gpio462/value > > rpi:~ # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > > pin 4 (gpio4) function gpio_out in hi; irq 83 (none) > > Ah, getting closer. This one starts with "in lo", and stays "in lo" aver > after writing 1 to value: > > # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > pin 4 (gpio4) function gpio_in in lo; irq 83 (none) > # echo 462 > /sys/class/gpio/export > # echo out > /sys/class/gpio/gpio462/direction > # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > pin 4 (gpio4) function gpio_out in lo; irq 83 (none) > # echo 1 > /sys/class/gpio/gpio462/value > # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > pin 4 (gpio4) function gpio_out in lo; irq 83 (none) > # echo 0 > /sys/class/gpio/gpio462/value > # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > pin 4 (gpio4) function gpio_out in lo; irq 83 (none) > # echo 1 > /sys/class/gpio/gpio462/value > # grep 'pin 4 ' /sys/kernel/debug/pinctrl/3f200000.gpio/pins > pin 4 (gpio4) function gpio_out in lo; irq 83 (none) > > This is the one that needed enable_uart=0 in extraconfig.txt or it would > stop on boot probably thinking there was serial line input... > So probably dodgy hardware. The pin is always supplying enough power for > a base of an NPN (emitter to ground) to make that NPN conductive at > least slightly. There was another person on the Internet whos pins > wouldn't switch until after he got his RPi replaced. I'll have a word > with Element14.
Can confirm there seems to be something wrong with the RPis GPIOs. Even tried to directly write to the registers from U-Boot, some pins worked as expected, some did not. Went through all the relevant registers - function-MUX, directions, drive strenght, ... - nothing helped. The pins worked neither as function pins (I2C in my case) nor as GPIOs. Some days/weeks later it suddenly worked again for some time. Kind regards, Stefan-- To unsubscribe, e-mail: opensuse-arm+unsubscr...@opensuse.org To contact the owner, e-mail: opensuse-arm+ow...@opensuse.org
