trouble with Open Cv and GPIO on mini6410 - c++

Question

I am doing a simple project on arm based mini6410. I have debian package installed on mini. My project is to interface one IR motion sensor and I USB webcam with the mini6410. the working will be simple, whenever there will be any motion detected by IR sensor, the webcam will be on for 30 seconds save the images (over write the previous) and then off.
I have already cross comiled the Open CV code using arm-linux-gcc
For IR I am using GPE register.
Here I am stuck with a issue which I am unable to resolve. and even dont know how to resolve. OpenCv code is a cpp file camera.cpp and the file which deals with I/O ports is a C file named sensor.c. Now in that c file I am polling or whatever mechanism to check if the GPE register is 1 or not. If it is one, I should start the Open CV code which will start to capture images. further more this sensor.c file is not to be compiled rather made a module and then insmod on my mini6410.
However I dont know how to write c++ code in a c file. you can say i dont know how to call the OpenCV thing from the C file. as it is a module and within this i cant write the cpp code as then using namespace std and using namespace cv doesnot work.
i am new to embedded stuff and linux it self. so I wanted to know are there some possible solutions.
i am attaching my codes of both files.
This is sensor.c
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/cdev.h>
#include <linux/miscdevice.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <mach/map.h>
#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>
#include <plat/gpio-cfg.h>
#include <mach/gpio-bank-q.h>
#include <mach/gpio-bank-e.h>
#include <mach/map.h>
#include <plat/regs-timer.h>
#include <mach/hardware.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/moduleparam.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <asm/unistd.h>
#include <mach/gpio-bank-k.h>
#define RLV 0x0FFF
unsigned Gpe;
unsigned sensor_value;
typedef struct
{
int delay;
} TIM_DEV;
static TIM_DEV TimDev;
static irqreturn_t INTHandler(int irq,void *TimDev)
{
Gpe = readl(S3C64XX_GPEDAT);
Gpe &= ~(0xF<<1);
readl(sensor_value, S3C64XX_GPEDAT);
while (sensor_value == 1)
{//1 means that IR sensor has detected a motion and given a value of +5 V
for (i = 0; i < 30; i++){
//CV_function();
// delay here such that delay(1 s) * 30 = 30 seconds
}
}
return IRQ_HANDLED;
}
static struct file_operations dev_fops = {
.owner = THIS_MODULE,
.write = MyWrite,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &dev_fops,
};
static int __init dev_init(void)
{
int ret;
unsigned TimerControl;
unsigned TimerINTControl;
unsigned TimerCNTB;
unsigned TimerCMPB;
unsigned TimerCFG1;
unsigned Ge;
TimerControl = readl(S3C_TCON);
TimerINTControl = readl(S3C_TINT_CSTAT);
TimerCNTB = readl(S3C_TCNTB(0));
TimerCMPB = readl(S3C_TCMPB(0));
TimerCFG1 = readl(S3C_TCFG1);
TimerCFG1 &= ~(S3C_TCFG1_MUX0_MASK);
TimerCNTB = RLV;
TimerCMPB = 0;
writel(TimerCNTB, S3C_TCNTB(0));
writel(TimerCMPB, S3C_TCMPB(0));
writel(TimerCFG1, S3C_TCFG1);
TimerControl |= S3C_TCON_T0MANUALUPD;
TimerINTControl |= S3C_TINT_CSTAT_T0INTEN;
writel(TimerControl, S3C_TCON);
writel(TimerINTControl, S3C_TINT_CSTAT);
TimerControl = readl(S3C_TCON);
TimerControl |= S3C_TCON_T0RELOAD;
TimerControl &= ~S3C_TCON_T0MANUALUPD;
TimerControl |= S3C_TCON_T0START;
writel(TimerControl, S3C_TCON);
//////////////Here I am configuring my GPE as input/////////////
Ge = readl(S3C64XX_GPECON);
Ge &= ~(0xFFFF<<4);
Ge |= (0x0000<<4);
writel(Ge, S3C64XX_GPECON);
/////////////
misc_register(&misc);
ret = request_irq(IRQ_TIMER0, INTHandler, IRQF_SHARED, DEVICE_NAME, &TimDev);
if (ret)
{
return ret;
}
return ret;
}
static void __exit dev_exit(void)
{
free_irq(IRQ_TIMER0, &TimDev);
misc_deregister(&misc);
}
module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("XYZ");
this is camera.cpp
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <stdio.h>
using namespace std;
using namespace cv;
int main( int argc, const char** argv )
{CvCapture* capture = 0;
Mat frame, frameCopy, image;
capture = cvCaptureFromCAM( 2 );
if( !capture )
{
cout << "No camera detected" << endl;
}
if( capture )
{
cout << "In capture ..." << endl;
IplImage* iplImg = cvQueryFrame( capture );
frame = iplImg;
if( frame.empty() )
break;
if( iplImg->origin == IPL_ORIGIN_TL )
frame.copyTo( frameCopy );
else
flip( frame, frameCopy, 0 );
cvSaveImage("image.jpg" ,iplImg);
}
cvReleaseCapture( &capture );
return 0;
}
the for loop in the sensor.c file should have my this above code by some means
I hope you get the idea,
Thanks

Answer 1

The missing link in the code shown is a mechanism by which the user-space code shown above can get notification of a change in the GPIO pin detected by the device driver.
There are two obvious ways to achieve this:
Integrate the GPIO pin into the platform's GPIO resources and then use the generic sysfs mechanism from user-space. The Linux kernel GPIO documentation describes both kernel and user-space side of this.
Have your driver expose a sysfs node for the GPIO line. sysfs is fundamental to the Linux Driver Model. I suggest a thorough read of Linux Device Drivers 3rd Edition.
The user-space side of either method is similar: You open the sysfs resource exported by your module and then use either poll() or select() to block until an event occurs.