Page History

→ Added configurations for support of gpio_keys module and evtest  - https://github.com/rdkcentral/meta-cmf-bananapi/pull/98
→ load the gpio-key module
root@Filogic-GW:/lib/modules/5.4.271-yocto-standard/kernel/drivers/input/keyboard# modprobe gpio_keys
root@Filogic-GW:/lib/modules/5.4.271-yocto-standard/kernel/drivers/input/keyboard# dmesg | grep gpio
[  163.696818] input: gpio-keys as /devices/platform/gpio-keys/input/input0
root@Filogic-GW:/lib/modules/5.4.271-yocto-standard/kernel/drivers/input/keyboard# cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 428-511, parent: platform/1001f000.pinctrl, pinctrl_moore:
 gpio-428 (                    |tx-disable          ) in  lo
 gpio-430 (                    |los                 ) in  hi IRQ
 gpio-432 (                    |asm_sel             ) in  hi
 gpio-433 (                    |pca9545_rst         ) in  hi
 gpio-441 (                    |reset               ) in  lo IRQ ACTIVE LOW
 gpio-442 (                    |wps                 ) in  hi IRQ ACTIVE LOW
 gpio-482 (                    |los                 ) in  hi IRQ
 gpio-498 (                    |tx-disable          ) in  lo
 gpio-510 (                    |mod-def0            ) in  hi IRQ ACTIVE LOW
 gpio-511 (                    |mod-def0            ) in  hi IRQ ACTIVE LOW
→ run the evtest
root@Filogic-GW:/lib/modules/5.4.271-yocto-standard/kernel/drivers/input/keyboard# evtest
No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0:      gpio-keys
Select the device event number [0-0]: 0
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100
Input device name: "gpio-keys"
Supported events:
  Event type 0 (EV_SYN)
  Event type 1 (EV_KEY)
    Event code 256 (BTN_0)
    Event code 529 (KEY_WPS_BUTTON)
Properties:
Testing ... (interrupt to exit)
Event: time 1739261802.084437, type 1 (EV_KEY), code 529 (KEY_WPS_BUTTON), value 1     # when HW WPS button pushed
Event: time 1739261802.084437, -------------- SYN_REPORT ------------
Event: time 1739261802.282856, type 1 (EV_KEY), code 529 (KEY_WPS_BUTTON), value 0     # when HW WPS button released

since buttons are associated with GPIO, we can do the export wps gpio using its number 
→ In mt7988a-bananapi-bpi-r4-nand.dts file, we can see WPS is defined with 14 
    wps {
                        label = "wps";
                        linux,code = <KEY_WPS_BUTTON>;
                        gpios = <&pio 14 GPIO_ACTIVE_LOW>;
                };
root@Filogic-GW:~# cd /sys/class/gpio/
export       gpiochip428/ unexport
→ Here by using 14+428=442, 428 (gpiochip428 refers to a GPIO controller that manages GPIO pins, starting from GPIO number 428.)
→ export the WPS pin number
root@Filogic-GW:/sys/class/gpio# echo 442 > /sys/class/gpio/export
root@Filogic-GW:/sys/class/gpio/gpio442# cat value
1
→ Whenever we press the WPS, this gpio442 value is changed to 0 
root@Filogic-GW:/sys/class/gpio/gpio442# cat value
0