testgpio.c

pxa270开发板,linux2.4内核,GPIO驱动源码,可以设置119个GPIO引脚(in/out 中断,预定义功能)

/*
THIS file is to test the gpio state and gpio interrupt
we set the gpio mod in GPIO_init,request irq in simple_init,
in the irq handler--simple_irq,we write_GPIO then we read_GPIO_state
*/

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>

#include <linux/miscdevice.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <asm/irq.h>
#include <linux/delay.h>

#include <asm/hardware.h>


#define GPIO_12 12
#define GPIO_11 11
#define GPIO_22 22
#define GPIO_17 17
#define GPIO_91 91
#define SIMPLE_MAJOR 235
#define SIMPLE_DEVICE_NAME "test_gpio"
#define SIMPLE_IRQ IRQ_GPIO(GPIO_12)   //the no. of the interrupt of gpio12 is dirived from the macro IRQ_GPIO()
//--------------------------------------------------------------------------------
static void write_GPIO(int gpio_nr);
static void read_GPIO_state(int gpio_port);
//-----------------------------------------------------------------------
static ssize_t simple_read (struct file *file, char  * buf, size_t count,loff_t * offset)
{
	printk("simple_read!\n");
	return 0;

}
static ssize_t simple_write (struct file *file, const char * buf, size_t count,loff_t * offset)
{
	printk("simple_write has been called\n");
	write_GPIO(GPIO_11);
	write_GPIO(GPIO_91);
	return 0;
}
int simple_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
	return 0;
}
static int simple_open(struct inode *inode, struct file *file)
{
	printk("simple_open has been called \n");
	return 0;
}
static int simple_release(struct inode *inode, struct file *file)
{
	printk("simple_release has been called\n");
	return 0;
}
static struct file_operations simple_fops = {
	.owner = THIS_MODULE,
	.read = simple_read,
	.write = simple_write,
	.ioctl = simple_ioctl,
	.open = simple_open,
	.release = simple_release,
};
//----------------------------------------------------------------------------
//set the gpio mode
static void GPIO_init(void)
{
	set_GPIO_IRQ_edge(GPIO_12, GPIO_RISING_EDGE); //set gpio12 be irq
	set_GPIO_mode(GPIO_11 | GPIO_OUT);    //set gpio 16 be alternate function 1,out
	set_GPIO_mode(GPIO_22 | GPIO_OUT);                      //set gpio 17 be in mode 
	set_GPIO_mode(GPIO_91 | GPIO_OUT);                   //set gpio 91 be out mod
	
}
//let the pin first be high then be low,after each set,there is a 2 second delay
static void write_GPIO(int gpio_nr)
{
	int i;
	printk("\nwriting to gpio... ...%d\n",gpio_nr);
	GPSR(gpio_nr)|=GPIO_bit(gpio_nr);
	printk("\nreading the gpio%d state after set ... ...\n",gpio_nr);
	read_GPIO_state(gpio_nr);
	for(i=1;i<200;i++)
		{
			mdelay(20);
		}
	GPCR(gpio_nr)|=GPIO_bit(gpio_nr);
	printk("\nreading the gpio state after clear... ...\n");
	read_GPIO_state(gpio_nr);
	for(i=1;i<200;i++)
		{
			mdelay(20);
		}
}

//irq handler,we write GPIO_91 for twice
static void simple_irq(int irq, void *dev_id, struct pt_regs *reg)
{
	printk("Now gpio interrupt occur!!!\n");
	write_GPIO(GPIO_11);
	write_GPIO(GPIO_11);
	write_GPIO(GPIO_11);
	//write_GPIO(GPIO_22);
	//write_GPIO(GPIO_91);	
}

//read the gpio's state by reading the relative bits in GPIO control registers
static void read_GPIO_state(int gpio_port)
{
	unsigned long gafr_mask,tmp;
	if((GPDR(gpio_port)&GPIO_bit(gpio_port)))
		printk("GPIO%d pin's direction is out\n",gpio_port);
	else
		printk("GPIO%d pin's direction is in\n",gpio_port);
	
	if((GPLR(gpio_port)&GPIO_bit(gpio_port)))
		printk("GPIO%d pin's voltage is high\n",gpio_port);
	else
		printk("GPIO%d pin's voltage is low\n",gpio_port);
	if((GRER(gpio_port)&GPIO_bit(gpio_port)))
		printk("GPIO%d pin's interrupt is rising edge\n",gpio_port);
	if((GEDR(gpio_port)&GPIO_bit(gpio_port)))
		printk("GPIO%d pin's  rising edge interrupt has occured\n",gpio_port);
	gafr_mask=GPIO_bit(gpio_port*2)|GPIO_bit(gpio_port*2+1); 
	tmp=(~GAFR(gpio_port))&gafr_mask;
	if(gafr_mask==tmp)
		printk("GPIO%d hasn't been set to alternate function yet\n",gpio_port);
	else
		printk("GPIO%d has already been set to alternate function!!\n",gpio_port);
}

static int __init simple_init(void)
{
	int ret,i;
	int t[6]={11,17,33,65,97,118};
	int j,x;
	unsigned long m[6];
	ret=register_chrdev(SIMPLE_MAJOR, SIMPLE_DEVICE_NAME, &simple_fops);
	if(ret)
		{
			printk(SIMPLE_DEVICE_NAME"can't register the device keypad");
		}
	
	printk("reading the gpio state befor gpio_init... ...\n");
	//read_GPIO_state(GPIO_12);
	read_GPIO_state(GPIO_11);
	//read_GPIO_state(GPIO_17);
	//read_GPIO_state(GPIO_91);
	GPIO_init();
	printk("\nreading the gpio state after gpio_init... ...\n");
	//read_GPIO_state(GPIO_12);
	read_GPIO_state(GPIO_11);
	//read_GPIO_state(GPIO_17);
	//read_GPIO_state(GPIO_91);
	ret=request_irq( SIMPLE_IRQ, &simple_irq, SA_INTERRUPT, SIMPLE_DEVICE_NAME, &simple_irq);
	printk("\nthe value irq return is %d\n",ret);
	if(ret)
		{
		unregister_chrdev(SIMPLE_MAJOR, SIMPLE_DEVICE_NAME);
        	printk(SIMPLE_DEVICE_NAME " can't request irqs\n");
        	return ret;	
		}
	else
		printk("irq successful!!!!\n\n");	
	
	return 0;
}
static void __exit simple_exit(void)
{
	
	free_irq(SIMPLE_IRQ,&simple_irq);
	unregister_chrdev(SIMPLE_MAJOR, SIMPLE_DEVICE_NAME);	
}
MODULE_LICENSE("GPL");
module_init(simple_init);
module_exit(simple_exit);