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Platform: ROCKCHIP

OS: Android 6.0

Kernel: 3.10.92

由于板子没有lcd无法得知sd卡升级是否完成,因此使用LED显示.

Recovery中升级完成后控制GPIO输出高电平点亮LED.

系统自带GPIO控制驱动:

内核已经自带了通用GPIO驱动,可以直接在用户空间操作.

路径: /sys/class/gpio

root@rk3288:/sys/class/gpio # ls

export

gpiochip0

gpiochip120

gpiochip152

gpiochip184

gpiochip216

gpiochip24

gpiochip248

gpiochip280

gpiochip56

gpiochip88

unexport

比如我要操作GPIO8_A6作为高电平输出有效, 那么有以下问题:

1. 对应的gpio number是多少呢?

2. 如何设置成输出

3. 如何输出高电平

问题1:

可以通过/sys/kernel/debug/gpio查询信息:

root@rk3288:/sys/kernel/debug # cat gpio                                       

//snip

GPIOs 184-215, platform/ff770000.pinctrl, gpio6:

 gpio-193 (?                   ) in  hi

 gpio-194 (?                   ) in  hi

GPIOs 216-247, platform/ff770000.pinctrl, gpio7:

 gpio-218 (enable              ) out hi

 gpio-219 (lcd_en              ) in  hi

 gpio-220 (lcd_cs              ) in  hi

 gpio-221 (gslX680 wake pin    ) out hi

 gpio-222 (gslX680 irq pin     ) out lo

 gpio-223 (headset_gpio        ) in  hi

 gpio-233 (?                   ) in  hi

 gpio-234 (?                   ) in  hi

GPIOs 248-279, platform/ff770000.pinctrl, gpio8:

GPIOs 280-311, platform/ff770000.pinctrl, gpio15:

可以看到gpio8是以nubmer为248开始, 那么GPIO8_A6就是 248 +　6 = 254

接下来就可以导出gpio了

root@rk3288:/sys/class/gpio # echo 254 > export                          

root@rk3288:/sys/class/gpio # ls

export

gpio254

......

问题2

root@rk3288:/sys/class/gpio/gpio254 # echo out > direction                     

root@rk3288:/sys/class/gpio/gpio254 # cat direction                            

out

问题3:

root@rk3288:/sys/class/gpio/gpio254 # echo 1 > value                           

root@rk3288:/sys/class/gpio/gpio254 # cat value                                

1

解决方法:

init.rc

[kris@:~/rk3288/device/rockchip/common/recovery/etc]$ g df

diff --git a/recovery/etc/init.rc b/recovery/etc/init.rc

index efe2a5d..75d7554 100755

--- a/recovery/etc/init.rc

+++ b/recovery/etc/init.rc

@@ -85,6 +85,12 @@ on late-init

 on property:sys.powerctl=*

    powerctl ${sys.powerctl}

 

+#Kris, 170407, GPIO8_A6 -> gpio254, used to inform sd upgrade complete.

+on property:sdupgrade.complete=true

+       write /sys/class/gpio/export 254

+       write /sys/class/gpio/gpio254/direction out

+       write /sys/class/gpio/gpio254/value 1

+

 service ueventd /sbin/ueventd

     critical

     seclabel u:r:ueventd:s0

recovery.cpp

[kris@:~/rk3288/bootable/recovery]$ g df

diff --git a/recovery.cpp b/recovery.cpp

index 8299672..a0edc15 100755

--- a/recovery.cpp

+++ b/recovery.cpp

@@ -2285,6 +2285,10 @@ HANDLE_STATUS :

         strcat(kernellogPath, "/kernel.txt");

         save_kernel_log(kernellogPath);

         #endif

+

+       //Kris, 170407, light led on after sd upgrade complete.

+       property_set("sdupgrade.complete", "true");

+

                if (bSDMounted)

             checkSDRemoved();

参考:

http://blog.csdn.net/cjsycyl/article/details/46310939