RK平台,RK3399,RK3288,IO控制。

一，硬件IO复用配置

配置复用 GPIO3 :FF790~ FF788; GPIO3_B7： GPIO io -4 -r 0xff79e014 GPIO3 FF79e054
iomux FF79e014

RK3399的iO控制 echo 227 > /sys/class/gpio/export GPIO7A3: 7X32 +3 = 227 gpio0B5 : 0X32+13 = 13

gpio3_B7: 3X32 + 15 = 111 echo 111 > /sys/class/gpio/export 配置GRF io -4 -r 0xff78800 [root@rk3399:/]# io -4 -r 0xff788000 ff788000: 00008000 [root@rk3399:/]# GRF基地址为：FF77_0000 GRF_GPIO3B_IOMUX 0x0e014 io 0xff77e015 > 0x15 cat /sys/kernel/debug/gpio GPIO控制 测试GPIO2_B2 写入GPIO2_B2位低电平 io -4 -w 0xff780000 0x7f0 红灯亮，设置生效 测试GPIO2_B3 写入GPIO2_B3为输出 io -4 -w 0xff780004 0x80ff1 GPIO2_B3输出为低 io -4 -w 0xff780000 0xff0 发现不生效，查询IOMUX寄存器 io -4 -r 0xff77e004 返回 0x00c0 查询寄存器文档可知bit7:6为11， gpio2_b3没有设为gpio 设置iomux为gpio io -4 -w 0xff7e004 0x0000 设置无效，可能是被驱动限制了 测试GPIO2_B1 bit位为(B-A)*8 + 1 = 9 由前面可知，DDR应该已经是输出 直接设置DR io -4 -w 0xff780000 0x5f0

二，另外一种用GPIO Debug接口控制的方法

以GPIO2_B2为例 查看GPIO2_B2的gpio number

1. rk3399:/sys/kernel/debug # cat gpio
   GPIOs 0-31, platform/pinctrl, gpio0: gpio-1 ( |vcc_sd ) out lo
   gpio-4 ( |bt_default_wake_host) in lo
   gpio-5 ( |power ) in hi
   gpio-9 ( |bt_default_reset ) out lo
   gpio-10 ( |reset ) out hi

GPIOs 32-63, platform/pinctrl, gpio1: gpio-34 ( |int-n ) in hi
gpio-35 ( |camsys_gpio ) out hi
gpio-45 ( |enable ) out hi
gpio-46 ( |vsel ) out lo
gpio-49 ( |vsel ) out lo
gpio-54 ( |mpu6500 ) in lo

GPIOs 64-95, platform/pinctrl, gpio2: gpio-64 ( |vbus-5v ) out lo
gpio-69 ( |power33 ) out hi
gpio-70 ( |power ) out hi
gpio-71 ( |reset ) out hi
gpio-72 ( |stanby ) out hi
gpio-73 ( |power18 ) out hi
gpio-74 ( |sysfs ) out lo
gpio-76 ( |int ) in hi
gpio-83 ( |bt_default_rts ) in hi
gpio-90 ( |bt_default_wake ) in lo 可知GPIO2_B2的number 为GPIO74 32*2 + 8+2

rk3399:/sys/class/gpio # echo 74 > export
1|rk3399:/sys/class/gpio # ls export gpiochip0 gpiochip32 gpiochip96 gpio74 gpiochip128 gpiochip64 unexport
rk3399:/sys/class/gpio #

rk3399:/sys/class/gpio/gpio74 # ls active_low device direction edge power subsystem uevent value rk3399:/sys/class/gpio/gpio74 # echo 1 > value
rk3399:/sys/class/gpio/gpio74 # echo 0 > value
rk3399:/sys/class/gpio/gpio74 #