设计原理图

引脚说明

主要初始化函数位置

aboard the file */ init.c located in */ bootable/bootloader/lk/target/M9PLUS_10/ , the initialization functions are implemented to control the keypad and volume buttons. For example, the function target_volume_up() initialize the volume up button by setting its config paramaters to input mode with pull-up enabled. After waiting for the debounce time, it checks the status to determine if the button is pressed.

次要代码

aboard the file */ dev/keys/keys.c/ , there is an initialization function keys_init() which sets up the key bitmap to ensure all keys are in their default states. This function is called during system boot to prepare the keyboard input layer for other functions.

主要外部调用函数

aboard the file */ pmic/pm8916/pm8916.c/ , several functions are provided to interact with the power management unit (pmic). For instance, pm_get_power_on_status() checks whether the power key is pressed, while pm_get_chg_voltage() provides the battery charging status.