Hello guys!
I haven't found any helpful regarding to my problem, maybe you are more professional as me! (I'm not really!)
I would like to set an ordered DHT22 temp & humidity sensor to work on this SBC.
OS is :
NAME="Ubuntu"
VERSION="18.04.3 LTS (Bionic Beaver)"
Kernel :
Linux cubieboard2 5.3.9-sunxi #19.11.3 SMP Mon Nov 18 18:49:43 CET 2019 armv7l armv7l armv7l GNU/Linux
I can export a pin as GPIO, and control a simple led.
I've built a kernel module for DHT22 found on github : https://github.com/edwardlintw/DHT22
The main problem is, after successful GPIO export :
echo 202 > /sys/class/gpio/export
cat /sys/kernel/debug/gpio | grep 202
gpio-202 ( |sysfs ) in lo
can't read a value!
It's all the same, I load a kernel module, or not, I get the following message :
gpioget gpiochip0 202
gpioget: error reading GPIO values: Device or resource busy
And with the kernel module :
insmod dht22.ko gpio=202
insmod: ERROR: could not insert module dht22.ko: Device or resource busy
In kernel.log I see followings :
[ 906.815645] sun4i-pinctrl 1c20800.pinctrl: 1c20800.pinctrl supply vcc-pg not found, using dummy regulator
[ 1224.340665] dht22: loading out-of-tree module taints kernel.
[ 1224.342543] Loading dht22 module...
[ 1224.359904] dht22 driver (major 241) installed
[ 1224.377611] dht22 failed to request GPIO 202, unloaded
If I don't create a pin for GPIO, result looks like :
Invalid parameters!
[ 97.922348] dht22: loading out-of-tree module taints kernel.
[ 97.924030] Loading dht22 module...
[ 97.942646] dht22 driver (major 241) installed
[ 97.960523] sun4i-pinctrl 1c20800.pinctrl: 1c20800.pinctrl supply vcc-pg not found, using dummy regulator
[ 97.961115] dht22 failed to get IRQ for GPIO 202, unloaded
What do I wrong? Could somebody give me some hint?
