Added Button Page

docs/helios64/button.md

@@ -0,0 +1,42 @@
+## Onboard Button
+
+![!Button location](img/button/button_location.jpg)
+
+### Power Button
+
+Helios64 board provides a POWER push button (PWR BTN) to power on/off the system.
+This button is connected to PMIC RK808-D.
+
+Short press (~1 second) will turn on the system when the current state is power off. On Linux, this will inform kernel to perform gracefull shutdown.
+
+Long press (~4 seconds **TBC**) will signals PMIC to cut off the power in case of system not responding (Force power off).
+
+This button also routed to Front Panel, so user don't need to open the case to power on/off the system.
+
+### Reset Button
+
+Helios64 board provides a RESET push button (RST BTN) to hard reset the board.
+
+This button also routed to Front Panel, so user don't need to open the case to hard reset the system.
+
+### Recovery Button
+
+User can enter recovery mode by pressing this button during boot up (bootloader stage). U-Boot will read this button and switch the USB type C into USB Mass Storage device with eMMC as the storage.
+User then can use Balena Etcher or dd to write OS image into eMMC.
+
+On Linux, this button behave as user button and when pressed will emit **BTN_0** keycode.
+
+This button also routed to Front Panel, so user don't need to open the case to enter Recovery Mode.
+
+
+## Front Panel Button
+
+For button location on front panel please refer to [Front Panel](/helios64/front-panel/#the-front-panel-description).
+
+### USR2 Button
+
+There is additional user button on Front Panel board located on [P2](/helios64/front-panel/#wiring-diagram). On Linux, this button when pressed will emit **BTN_1** keycode.
+
+
+## References
+[input-event-codes.h](https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/plain/include/uapi/linux/input-event-codes.h)

docs/helios64/hardware.md

@@ -42,9 +42,9 @@ This block diagram is cited from the RK3399 website documentation. [1](http://op
 | P3 | [Front Panel Header](/helios64/front-panel/) | 12x2 Pin Male Header | PWM and RPM support |
 | P4 | Buzzer Header | 2x1 Pin Header | Buzzer Speaker Support |
 | P5 | [GPIO Pin Header](/helios64/gpio/) | 7x2 Pin Male Header | GPIO configurable as input or output<br>Via IO Expander on I2C Bus 0 |
-| PWR BTN | Power Button | Push Button | Power Button |
-| RECOVERY | Recovery Button | Push Button |  |
-| RST BTN | Reset Button | Push Button | Reset Button |
+| PWR BTN | [Power Button](/helios64/button/#power-button) | Push Button | Power Button |
+| RECOVERY | [Recovery Button](/helios64/button/#recovery-button) | Push Button |  |
+| RST BTN | [Reset Button](/helios64/button/#reset-button) | Push Button | Reset Button |
 
 ## Reset Button
 

mkdocs.yml

@@ -78,6 +78,7 @@ nav:
     - Overview : 'helios64/hardware.md'
     - Battery : 'helios64/battery.md'
     - Boot Mode : 'helios64/boot_mode.md'
+    - Button : 'helios64/button.md'
     - Front Panel (P3): 'helios64/front-panel.md'
     - GPIO (P5): 'helios64/gpio.md'
     - I2C : 'helios64/i2c.md'