firefly-rk3288 设备树引用GPIO引脚计算@TOC

例如: GPIO5_B4
GPIO5 BANK = 5
PIN计算: A=0 B=1 C=2 D=3
例如: B4 PIN = 1 * 8 + 4 = 12
gpionumber = BANK * 32 + PIN
gpionumber为 5 * 32 + 1 * 8 + 4 = 172
设备树中引用为:
gpios = <&(gpio label) PIN GPIO_ACTIVE_LOW>;
gpios = <&gpio5 12 GPIO_ACTIVE_LOW>;
以此类推.