GPIO中断

主要功能：通过两个GPIO（S5PV210_GPJ2（7）和S5PV210_GPJ3（0））作为输出，来控制两个作为中断的GPIO（S5PV210_GPH1（4）和S5PV210_GPH1（2）），从而触发两个LED灯（ S5PV210_GPH0(6)和S5PV210_GPH0(7)）。

主要参考文件linux/interrupt.h， kernel/irq/manage.c， linux/irq.h， kernel/arch/arm/mach-s5pv210/include/mach/irqs.h， kernel/arch/arm/mach-s5pv210/include/mach/gpiolib.c

GPIO中断申请的主要步骤：

1.GPIO注册

2.GPIO中断设置

3.设置GPIO中断的触发方式

4.使能GPIO中断

5.中断注册

GPIO中断驱动

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/*
 * gpio_light.c
 * @Date :11.15.2012
 */

#include <mach/irqs.h>
#include <asm/uaccess.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/interrupt.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>



#define LIGHT_ON    1
#define LIGHT_OFF    0

#define DEVICE_NAME    "gpio_light"
#define CLASS_NAME    "light_class"

static dev_t devid;
static struct cdev light_cdev;
static struct class *light_class;

static struct gpio gpios_light[] = {
    { S5PV210_GPH0(6), GPIOF_OUT_INIT_HIGH, "LED1" },
    { S5PV210_GPH0(7), GPIOF_OUT_INIT_HIGH, "LED2" },
    { S5PV210_GPJ2(7), GPIOF_OUT_INIT_LOW, "CONTROL1" },
    { S5PV210_GPJ3(0), GPIOF_OUT_INIT_LOW, "CONTROL2" },
};

struct gpio_irqs_desc {
    int irq;
    int irq_type;
    int pin;
    int pin_setting;
    int number;
    char *name;
};
static struct gpio_irqs_desc gpio_irqs [] = {
    {IRQ_EINT12, IRQ_TYPE_EDGE_RISING, S5PV210_GPH1(4), S3C_GPIO_SFN(0xf), 0, "GPIO_IRQ_LED1"},
    {IRQ_EINT10, IRQ_TYPE_EDGE_RISING, S5PV210_GPH1(2), S3C_GPIO_SFN(0xf), 1, "GPIO_IRQ_LED2"},
};


void led_on(int cmd)
{
     gpio_set_value(gpios_light[cmd].gpio, 0);
     printk("Sucess to turn on the %s ! \n", gpios_light[cmd].label);
}
void led_off(int cmd)
{
     gpio_set_value(gpios_light[cmd].gpio, 1);
     printk("Sucess to turn off the %s ! \n", gpios_light[cmd].label);
}

static irqreturn_t light_intHandle(int irq, void *dev_id)
{
    struct gpio_irqs_desc *gpio_irqs = (struct gpio_irqs_desc *)dev_id;
    led_on(gpio_irqs->number);
    printk("Sucess to link GPIO with LED ! \n");
    return IRQ_HANDLED;
}

static void real_gpio_irqs_init(void)
{
    int err, i;
    for (i = 0; i < sizeof(gpio_irqs)/sizeof(gpio_irqs[0]); i++)
    {
        err = gpio_request(gpio_irqs[i].pin, gpio_irqs[i].name); //1.GPIO注册
        if (err) {
            pr_err("Failed to request %s ! \n", gpio_irqs[i].name);
        }

        err = s3c_gpio_cfgpin(gpio_irqs [i].pin, gpio_irqs[i].pin_setting); //2.将GPIO设置为中断状态
        if (err) {
            pr_err("Failed to set the %s with interrupting !\n",
                    gpio_irqs[i].name);
        }

        set_irq_type(gpio_irqs[i].irq, gpio_irqs [i].irq_type); //3.设置GPIO中断的触发方式

        disable_irq(gpio_irqs[i].irq);
        enable_irq(gpio_irqs[i].irq); //4.使能GPIO中断
        err = request_irq(gpio_irqs[i].irq,light_intHandle, 0,gpio_irqs[i].name, //5.中断注册
                        (void *)&gpio_irqs[i]);
        printk("request_irq = %d !!!\n", err);
        if(err)
            pr_err("Failed to request the %s ! \n", gpio_irqs[i].name);
    }

}

static int gpios_light_open(struct inode *inode, struct file *filp)
{
    int err;
    printk("Sucess to open the gpios_light_open ! \n");
    real_gpio_irqs_init();//完成GPIO中断注册
    err = gpio_request_array(gpios_light, ARRAY_SIZE(gpios_light));
    if (err) {
        pr_err("Failed to request GPIO LIGHT ! \n");
    }
    return err;
}

static int gpios_light_close(struct inode *inode, struct file *filp)
{
    int i;
    for (i = 0; i < sizeof(gpio_irqs)/sizeof(gpio_irqs[0]); i++)
    {
        free_irq(gpio_irqs[i].irq,(void *)&gpio_irqs[i]);
        gpio_free(gpio_irqs[i].pin);
    }


    gpio_free_array(gpios_light, ARRAY_SIZE(gpios_light));
    pr_err("Sucess to close ! \n");
    return 0;
}

static int gpios_light_ioctl(struct inode *inode, struct file *filp,
        unsigned int cmd, unsigned long arg)
{
    switch (cmd) {
        case LIGHT_ON:
            gpio_set_value(gpios_light[arg + 1].gpio, 1);
            break;
        case LIGHT_OFF:
            gpio_set_value(gpios_light[arg + 1].gpio, 0);
            led_off(arg-1);
            break;
        default:
            return -EINVAL;
    }
    return 0;
}


static struct file_operations gpio_light_fops = {

    .owner        = THIS_MODULE,
    .open        = gpios_light_open,
    .release    = gpios_light_close,
    .ioctl        = gpios_light_ioctl,
};

static int __init gpio_light_init(void)
{
    int err;
    struct device *pdev;

    err = alloc_chrdev_region(&devid, 0, 1, DEVICE_NAME);
    if (err < 0) {
        pr_err("Failed to allocate LIGHT device numbers\n");
        goto fail;
    }

    cdev_init(&light_cdev, &gpio_light_fops);
    light_cdev.owner = THIS_MODULE;
    err = cdev_add(&light_cdev, devid, 1);
    if (err < 0) {
        pr_err("Failed to add LIGHT device\n");
        goto unregister_dev_num;
    }

    light_class = class_create(THIS_MODULE, CLASS_NAME);
    if (IS_ERR(light_class)) {
        pr_err("Failed to create LIGHT class\n");
        err = PTR_ERR(light_class);
        goto delete_cdev;
    }

    pdev = device_create(light_class, NULL, devid, NULL, DEVICE_NAME);
    if (IS_ERR(pdev)) {
        pr_err("Failed to create LIGHT device\n");
        err = PTR_ERR(pdev);
        goto destroy_class;
    }

    return 0;

destroy_class:
    class_destroy(light_class);

delete_cdev:
    cdev_del(&light_cdev);

unregister_dev_num:
    unregister_chrdev_region(devid, 1);

fail:
    return err;
}

static void __exit gpio_light_exit(void)
{
    device_destroy(light_class, devid);
    class_destroy(light_class);
    cdev_del(&light_cdev);
    unregister_chrdev_region(devid, 1);
}

module_init(gpio_light_init);
module_exit(gpio_light_exit);
MODULE_LICENSE("GPL");

测试程序

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/*
 * lighttest.c
 *
 * Created on: 2012-11-13
 *
 */

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/ioctl.h>

#define DEVICE_PATH        "/dev/gpio_light"

int main(void)
{
    int fd;
    int input,led;

    fd = open(DEVICE_PATH, O_RDWR);
    printf("open = %d\n", fd);
    if (fd == -1)
    {
        perror("Can't open " DEVICE_PATH);
        return fd;
    }else
        printf("Sucess to open " DEVICE_PATH);

    printf("\nPlease input which led (1, 2)\n");
    printf("and input switch mode (1, 0):\n");
    while (scanf("%d %d",&led, &input) == 2) {
        int ret = ioctl(fd, input, led);
        printf("ret = %d \n",ret);
    }

    close(fd);
    return 0;
}