355x，内核使用定时器demo

博主使用的板子是天嵌科技的335xB

内核版本：linux3.2

驱动demo：

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

#define    MY_MAJOR     231
#define    DEVICE_NAME     "myModule"
#define GPIO_TO_PIN(bank, gpio) (32 * (bank) + (gpio))
static struct omap_dm_timer *timer;
int irq;

static int mydemo_open(struct inode *inode, struct file *file){
        printk(KERN_EMERG "hello open.\n");
        return 0;
}

static int mydemo_write(struct file *file, const char __user * buf, size_t count, loff_t *ppos){
    printk(KERN_EMERG "hello write.\n");    
    return 0;
}

static struct file_operations mydemo_flops = {
        .owner  =   THIS_MODULE,
        .open   =   mydemo_open,     
        .write  =   mydemo_write,
};

static irqreturn_t mytimer_interrupt(int irq, void *dev){
        
    //printk(KERN_ERR"TIMER 7 is_running !!!!!!!!!!!!\n");
    char gpio_v = !(gpio_get_value(GPIO_TO_PIN(3, 21)));
        gpio_set_value(GPIO_TO_PIN(3, 21), gpio_v);        
    return IRQ_HANDLED;
}

static int __init mydemo_init(void){
        int ret;
    ret = register_chrdev(MY_MAJOR,DEVICE_NAME, &mydemo_flops);
        if (ret < 0) {
              printk(KERN_EMERG DEVICE_NAME " can't register major number.\n");
              return ret;
        }
        printk(KERN_EMERG DEVICE_NAME " initialized.\n");
    
    gpio_request(GPIO_TO_PIN(3,21),"gpio117");
        gpio_direction_output(GPIO_TO_PIN(3,21), 0);

    timer = omap_dm_timer_request_specific(7);    //得到定时器7
    irq =  omap_dm_timer_get_irq(timer);        //得到中断号
    ret = request_irq(irq,mytimer_interrupt, IRQF_DISABLED | IRQF_TIMER , "heat_timer_init",NULL);//注册中断
    omap_dm_timer_set_load(timer, 0, 0xFFFFFFFF-500);
    omap_dm_timer_write_counter(timer, 0xFFFFFFFF-500);

    /* Enable overflow interrupt */
    omap_dm_timer_set_int_enable(timer, OMAP_TIMER_INT_OVERFLOW);
    /*
     * Set counter value to overflow counter after
     * one tick and start timer.
     */
    //omap_dm_timer_set_load_start(timer, 0, load);
    // start the timer!
    omap_dm_timer_start(timer);
    // stop the timer!
    //omap_dm_timer_stop(timer);

        return 0;
}

static void __exit mydemo_exit(void){
        unregister_chrdev(MY_MAJOR, DEVICE_NAME);
    omap_dm_timer_free(timer);
    free_irq(irq,NULL);
        printk(KERN_EMERG DEVICE_NAME " removed.\n");
}

module_init(mydemo_init);
module_exit(mydemo_exit);
MODULE_LICENSE("GPL");