Hi,
I’m using (amongst others) gpio 1_10 on the imx6ull as a gpio key. It is externally pulled to 3.3V and a switch pulls it to ground when pressed.
device tree entry:
front-switch8 {
label = “front_switch_8”;
gpios = <&gpio1 10 GPIO_ACTIVE_LOW>;
linux,code = <KEY_F8>;
debounce-interval = <10>;
};
pin mux setup:
MX6UL_PAD_JTAG_MOD__GPIO1_IO10 0x10b0
I noticed that compared to other gpio’ s used in the gpio keys, this one generated a lot of interrupts even hanging the system. I measured the voltage on the line and it does not get pulled to 3.3Volt but only reached ~1.7V
I saw that this pin in the Toradex software is used as a reset pin for Atmel maxtouch controller.
So I measured in the original setup and saw the Voltage at 1.8V.
I copied the mux setting used for the reset and set it to be:
MX6UL_PAD_JTAG_MOD__GPIO1_IO10 0xb0a0
Now the interrupt storm is fixed (Voltage is slightly higher) however I still only get 1.8V so somewhere I drop 1.5V
I could not find in the manual that is in a 1.8 Volt domain or so.
Can I use this gpio in this situation or should I not be using this gpio with 3.3V pullup?
hardware: imx6ull, custom base board,
software: Reference-Minimal-Image-colibri-imx6ull, Linux colibri-imx6ull 5.4.129
Best Regards,
Vincent