I am currently trying to use the arduino headers on the evalkit to control LEDs via the generic leds-gpio driver. My problem is, that I can not use most of the pins and I don't know why.
What I did:
I changed the imx6ull-14x14-evk.dts to include the following:
leds {
compatible = "gpio-leds";
my_red_led {
label = "rgb_r";
gpios = <&gpio1 20 GPIO_ACTIVE_HIGH>;
};
my_green_led {
label = "rgb_g";
gpios = <&gpio1 21 GPIO_ACTIVE_HIGH>;
};
my_blue_led {
label = "rgb_b";
gpios = <&gpio1 24 GPIO_ACTIVE_HIGH>;
};
my_white_led {
label = "white_led";
gpios = <&gpio1 25 GPIO_ACTIVE_HIGH>;
};
};
In addition to that, I commented out the following sections:
pinctrl_uart2: uart2grp{...};
&uart2 {...};
What works:
All 4 LEDs show up under /sys/class/leds/
When I call
echo 255 > /sys/class/leds/{name_of_led}/brightness
the LEDs on pin 20, 21 and 25 can be turned on.
The pins 30,31 also work when I take out I2C (but I need it so I can not use those pins).
What doesn't work:
The LED on pin 24 can not be turned on.
I put some printk()-calls in the kernel module to check for errors, but the driver is working correctly.
I also tried some other arduino pins (those named GPIO0-4, SD1_DATA0-3, SD1_CLK, SD1_CMD and ECSPI4_* on the schematics) but they also don't work.
I always took out the components that use the pins in the dts-file to make sure the drivers don't re-configure the pins.
I also tried manually setting the pins using the following (adapted to each individual pin)
gpioset gpiochip0 24=1
When I call:
gpioinfo
I can see that the pin is configured as "output" with "active-high" value.
My question:
What do I have to do/change in the dts-file in order to use pin 24 (or one of the other pins mentioned)?
