Android under Debug 3G Gpio control 3G Power on

If you are developing your own board, you need to use the GPIO pin to control the 3G module boot/shutdown, the following article will be helpful to you, is the processor IMX6 and ZTE MG3732 module as an example.

One, pin connection

The processor's gpio3_gpio[9] connects the on/off (29) pin of the 3G module to control the power on/off of the 3G.

Second, switch machine conditions

The On/off pin is turned on continuously 2500~3500 milliseconds low, and the on/ off pins are switched off continuously 2500~3500 milliseconds low.

Third, Gpio driver

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_OFFIMX_GPIO_NR (3,9)//Control pin: 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);p RINTK ("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);p RINTK ("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");d evice_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);d Evice_destroy (MY_CLASS,DEVNO); Class_destroy (My_class );p RINTK (kern_info "char device GPIO unregister\n");} Module_init (Gpio_init); Module_exit (Gpio_exit);

Iv. kernel Add gpio driver Step (android4.3 source)

1, put gpio_3g.c into the ~/myandroid/kernel_imx/drivers/char directory (assuming the source code under ~/myandroid).

2, ~/myandroid/kernel_imx/drivers/char/konfig the last Add the red box part of the statement.

3, add a red box part of the statement in ~/myandroid/kernel_imx/drivers/char/makefile.

4, under ~/MYANDROID/KERNEL_IMX make menuconfig to configure the kernel, after the configuration is complete, exit and save. Such as:

5, in the Entry ~/myandroid/kernel_imx directory execution:

cp. config Arch/arm/configs/imx6_android_defconfig

After that, the following command compiles:

SOURCE build/enevsetup.sh

Lunch Sabresb_6dq-user

Make

Five, compile 3G module switch machine program

1. Program code

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          0x00int Main (int argc, char *argv[]) {int Fd;fd=open ("/dev/gpio _3g ", O_RDWR); Open the GPIO_3G device file if (fd<0) {perror ("open:");} if (IOCTL (fd,3g_output,set_on) <0) {//Set this PIN for output high perror ("3g_output ioctl:");} Sleep (3); if (IOCTL (Fd,3g_output,set_off) <0) {//Set this pin as output low perror ("3g_output ioctl:");} if (IOCTL (Fd,3g_input,set_off) <0) {//Set this pin as input to prevent accidental tampering perror ("3g_input ioctl:");} Close (FD); return 0;}

Android.mk

local_path:=$ (call My-dir) include$ (clear_vars) local_module_tages:=optionallocal_module:=3g_on_offlocal_src_ files:=3g_on_off.cinclude$ (build_executable)

2. Create the 3g_on_off folder under ~/myandroid/external

3. Place the 3G_ON_OFF.C and android.mk files under the new folder.

4. Execute the following command to compile:

SOURCE build/enevsetup.sh

Lunch Sabresb_6dq-user

Mmm External/3g_on_off

5, the generated executable program:

~/myandroid/out/target/product/sabresd_6dq/obj/executables/3g_on_off_intermediates/3g_on_off put it in

~/myandroid/out/target/product/sabresd_6dq/system inside

Execution: Make Snod packaging

Six, burn write image to the development Board, execute the 3G_ON_OFF program to switch the 3G module to operate.

Android under Debug 3G Gpio control 3G Power on