RK3399 Android7.1在uboot中设置GPIO状态

比如我在uboot中设置某个IO口的初始电平状态：

diff --git a/u-boot/board/rockchip/common/rkloader/key.c b/u-boot/board/rockchip/common/rkloader/key.c
index 495bd82..25e2654 100755
--- a/u-boot/board/rockchip/common/rkloader/key.c
+++ b/u-boot/board/rockchip/common/rkloader/key.c
@@ -328,6 +328,7 @@ void powerOn(void)
 {
        int flash_led=0,ret=0;
        int pwr_4g = 0;
+       int camera2_rst=0;
        if (power_hold_gpio.name != NULL) {
                gpio_direction_output(power_hold_gpio.gpio, power_hold_gpio.flags);
        }
@@ -352,6 +353,36 @@ void powerOn(void)
                gpio_direction_output(pwr_4g,0);
                gpio_set_value(pwr_4g,1);
        }

//gpio_pull_updown(sf2507_vddl_en,GPIOPullUp);
+       
+       camera2_rst = GPIO_BANK2|GPIO_A7;        //GPIO2_A7
+       ret = gpio_request(camera2_rst,"camera2_rst_control");
+       if(ret)
+               printf("nrequest camera2_rst control failed!n");
+       else
+       {
+               gpio_direction_output(camera2_rst,0);
+               gpio_set_value(camera2_rst,0);
+       }