android下除錯3G之gpio控制3G上電
如果是自己開發的板子,需要用GPIO引腳控制3G模組開機/關機時,下面的文章會對你有所幫助,是以處理器IMX6和中興MG3732模組為例介紹。
一、引腳連線
處理器的gpio3_GPIO[9]連線3G模組的ON/OFF(29)引腳來控制3G的開機/關機。
二、開關機條件
給ON/OFF引腳連續2500~3500毫秒低電平則開機,給再ON/OFF引腳連續2500~3500毫秒低電平則關機。
三、gpio驅動程式
gpio_3g.c
#include<linux/module.h> #include<linux/kernel.h> #include<linux/init.h> #include<linux/fs.h> #include<linux/cdev.h> #include<linux/device.h> #include<asm/io.h> #include<linux/mm.h> #include<asm/uaccess.h> #include<linux/gpio.h> #define GPIO_IOF_MAGIC 0xd0 #define 3G_INPUT _IO(GPIO_IOF_MAGIC,8) #define 3G_OUTPUT _IO(GPIO_IOF_MAGIC,9) #define 3G_ON_OFF IMX_GPIO_NR(3,9) //控制引腳為:gpio3[9] MODULE_LICENSE ("GPL"); int gpio_major=2555; int gpio_minor=0; int number_devices=1; struct cdev gpiocdev; struct class *my_class; static int gpio_open(struct inode *inode,struct file *file) { printk (KERN_INFO "GPIO device opened\n"); if(gpio_direction_output(3G_ON_OFF,0x00)<0){ printk("3G_ON_OFF set direction failed\n"); } return 0; } static long gpio_ioctl(struct file *file,unsigned int cmd,unsigned long arg) { int val; printk("GPIO:ioctl running....\n"); switch(cmd){ case 3G_INPUT: if(gpio_direction_input(3G_ON_OFF)<0){ printk("3G_ON_OFF set input failed\n"); } if(arg>0){ gpio_set_value(3G_ON_OFF,0x01); }else{ gpio_set_value(3G_ON_OFF,0x00); } val=gpio_get_value(3G_ON_OFF); printk("3G_ON_OFF ioctl val=%d\n",val); break; case 3G_OUTPUT: if(gpio_direction_output(3G_ON_OFF,0x00)<0){ printk("3G_ON_OFF set direction failed\n"); } if(arg>0){ gpio_set_value(3G_ON_OFF,0x01); }else{ gpio_set_value(3G_ON_OFF,0x00); } val=gpio_get_value(3G_ON_OFF); printk("3G_ON_OFF ioctl val=%d\n",val); break; default: printk("cmd is not exist\n"); return -1; } return val; } static int gpio_release (struct inode *inode, struct file *file) { printk (KERN_INFO "GPIO device closed\n"); return 0; } struct file_operations gpio_fops = { .owner=THIS_MODULE, .open=gpio_open, .release=gpio_release, .unlocked_ioctl=gpio_ioctl, }; static void char_reg_setup_cdev (void) { int error; dev_t devno; devno=MKDEV(gpio_major,gpio_minor); cdev_init(&gpiocdev,&gpio_fops); gpiocdev.owner=THIS_MODULE; error=cdev_add(&gpiocdev,devno,1); if (error) printk(KERN_NOTICE "Error %d adding char device GPIO",error); } static int __init gpio_init (void) { int result; dev_t devno; devno=MKDEV(gpio_major,gpio_minor); if(gpio_major){ result=register_chrdev_region(devno,number_devices,"gpio_3g"); }else{ result=alloc_chrdev_region(&devno,0,number_devices,"gpio_3g"); gpio_major=MAJOR(devno); } if (result<0){ printk(KERN_WARNING "GPIO:can't get major number %d\n", gpio_major); return result; } char_reg_setup_cdev (); my_class=class_create(THIS_MODULE,"GPIOCLASS"); device_create(my_class,NULL,MKDEV(gpio_major,gpio_minor),NULL,"gpio_3g"); if(gpio_request(3G_ON_OFF,"UnKnow")<0){ printk("3G_ON_OFF request failed\n"); } printk (KERN_INFO "char device GPIO registered\n"); return 0; } static void __exit gpio_exit(void) { dev_t devno=MKDEV(gpio_major,gpio_minor); gpio_free(3G_ON_OFF); cdev_del(&gpiocdev); unregister_chrdev_region(devno,number_devices); device_destroy(my_class,devno); class_destroy(my_class); printk(KERN_INFO"char device GPIO unregister\n"); } module_init (gpio_init); module_exit (gpio_exit);
四、核心新增gpio驅動步驟(android4.3原始碼)
1、把gpio_3g.c放到~/myandroid/kernel_imx/drivers/char目錄下(假設原始碼在~/myandroid下)。
2、~/myandroid/kernel_imx/drivers/char/Konfig中最後新增紅色框部分語句。
3、在~/myandroid/kernel_imx/drivers/char/Makefile中新增紅色框部分語句。
4、在~/myandroid/kernel_imx下 make menuconfig 來配置核心,配置完成後退出並儲存。如下圖:
5、在進入~/myandroid/kernel_imx目錄執行:
cp .config arch/arm/configs/imx6_android_defconfig
到此後,行以下命令編譯:
source build/enevsetup.sh
lunch sabresb_6dq-user
make
五、編譯3G模組開關機程式
1、程式程式碼
3g_on_off.c
#include<stdio.h>
#include<unistd.h>
#include<fcntl.h>
#include<errno.h>
#include<sys/ioctl.h>
#include<sys/types.h>
#define 3G_INPUT _IO(GPIO_IOF_MAGIC,8)
#define 3G_OUTPUT _IO(GPIO_IOF_MAGIC,9)
#define SET_ON 0x01
#define SET_OFF 0x00
int main(int argc, char *argv[])
{
int fd;
fd=open("/dev/gpio_3g",O_RDWR); //開啟gpio_3g裝置檔案
if(fd<0){
perror("open:");
}
if(ioctl(fd,3G_OUTPUT,SET_ON)<0){ //設定該引腳為輸出高
perror("3G_OUTPUT ioctl:");
}
sleep(3);
if(ioctl(fd,3G_OUTPUT,SET_OFF)<0){ //設定該引腳為輸出低
perror("3G_OUTPUT ioctl:");
}
if(ioctl(fd,3G_INPUT,SET_OFF)<0){ //設定該引腳為輸入,防止被意外篡改
perror("3G_INPUT ioctl:");
}
close(fd);
return 0;
}
Android.mk
LOCAL_PATH :=$(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGES :=optional
LOCAL_MODULE :=3g_on_off
LOCAL_SRC_FILES :=3g_on_off.c
include $(BUILD_EXECUTABLE)
2、在~/myandroid/external下建立 3g_on_off資料夾
3、把 3g_on_off.c 和 Android.mk 檔案放到新建資料夾下。
4、執行以下命令編譯:
source build/enevsetup.sh
lunch sabresb_6dq-user
mmm external/3g_on_off
5、把生成的可執行程式:
~/myandroid/out/target/product/sabresd_6dq/obj/EXECUTABLES/3g_on_off_intermediates/3g_on_off放到
~/myandroid/out/target/product/sabresd_6dq/system裡面
執行:make snod 打包
六、燒寫映象到開發板,執行3g_on_off程式對3G模組進行開關機操作。
3G上電後,連線板子的除錯串列埠終端會輸出以下紅色框的資訊,此時表明已識別USB串列埠裝置