4412驱动-poll阻塞 -二

驱动

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h> //request_irq
#include <mach/irqs.h> //中断号，已包含plat/irqs.h
#include <linux/fs.h>
#include <linux/device.h> //class_create device_create
#include <mach/regs-gpio.h>
#include <linux/io.h> //ioremap ioread32 iowrite32
#include <linux/sched.h>
#include <linux/of.h>  
#include <linux/of_device.h>  
#include <linux/delay.h>  
#include <linux/poll.h>

#define DEV_NAME    "poll-dev"  
static struct class *polldrv_class;
static struct class_device	*polldrv_class_dev;

struct led_reg {	
	u32 gpm4con;
	u8 gpm4dat;
	};
static struct led_reg *led_reg;

struct key_reg {	
	u32 gpm4con;
	u8 gpm4dat;
	};
static struct key_reg *key_reg;

struct beep_reg {	
	u32 gpm4con;
	u8 gpm4dat;
	};
static struct key_reg *beep_reg;

static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

/* 中断事件标志, 中断服务程序将它置1，poll_drv_read将它清0 */
static volatile int ev_press = 0;

/* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 */
/* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */
static unsigned char key_val;

int major;
/*
  * 确定按键值
  */
static irqreturn_t buttons_irq(int irq, void *dev_id)
{	
	printk("buttons_irq\n");
    //获取按键的键值，因为按键是从该寄存器的第二位开始的，所以需要左移2位，接着与上0xf---1111
	//这样，如果用户按下按键，就会返回一个键值保存在key_val这个变量里 
     key_val = ((key_reg->gpm4dat) >> 2) & 0xf ;
	printk("key_val_irq= %d\n",key_val);
    ev_press = 1;                  /* 表示中断发生了 */
    wake_up_interruptible(&button_waitq);   /* 唤醒休眠的进程 */

	
	return IRQ_RETVAL(IRQ_HANDLED);
}

static int poll_drv_open(struct inode *inode, struct file *file)
{
	int ret;
	printk("poll_open\n");
	//配置4个按键为输入状态，因为按键是从GPXCON[2]开始的，所以要左移8位到对应的位置，将8位以后的16位清0
	//这样的话就将按键配置的寄存器设置为输入状态了，因为输入是0x0 
	key_reg->gpm4con  &= ~((0xf<<(2*4)) | (0xf<<(3*4)) | (0xf<<(4*4)) | (0xf<<(5*4)));
	
	//先对LED的端口进行清0操作
	led_reg->gpm4con  &= ~((0xf<<(3*4)) | (0xf<<(2*4)) | (0xf<<(1*4)) | (0xf<<(0*4)));
	//将4个IO口16位都设置为Output输出状态
	led_reg->gpm4con |= ((0x1<<(3*4)) | (0x1<<(2*4)) | (0x1<<(1*4)) | (0x1<<(0*4)));

	//清寄存器 
	beep_reg->gpm4con &= ~(0xf);
	//设置io为输出 
	beep_reg->gpm4con |= (0x1);
	
	
	ret =request_irq(IRQ_EINT(27), buttons_irq, IRQF_TRIGGER_FALLING, "k2", "k2");	
	ret =request_irq(IRQ_EINT(28), buttons_irq, IRQF_TRIGGER_FALLING, "k3", "k3");
	ret =request_irq(IRQ_EINT(29), buttons_irq, IRQF_TRIGGER_FALLING, "k4", "k4");	
	ret = request_irq(IRQ_EINT(26), buttons_irq, IRQF_TRIGGER_FALLING, "k1", "k1");	
	if (ret < 0) 
	{		
		printk("request_irq faild\n");		
		return -EINVAL;	
	}
	return 0;
}

ssize_t poll_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
	if (size != 1)
		return -EINVAL;

	/* 如果没有按键动作, 休眠 */
	wait_event_interruptible(button_waitq, ev_press);

	/* 如果有按键动作, 返回键值 */
	copy_to_user(buf, &key_val, 1);
	printk("read_val_irq= %d\n",key_val);
	ev_press = 0;
	
	return 1;
}



//write方法
int poll_drv_write(struct file *filp , const char __user *buf , size_t count , loff_t *f_pos)
{
	int val ; 
	//注意，这里是在内核中进行操作，我们需要使用copy_from_user这个函数将用户态的内容拷贝到内核态
	copy_from_user(&val , buf , count);	
	//以下就是当val是哪个值的时候，led就执行相应的操作，这里不多说
	switch(val)
	{
		case 0 : 
		        //对状态寄存器进行赋值,以下雷同
				printk(KERN_EMERG"led1_on\n");
				led_reg->gpm4dat &= ~(1<<0) ;
				beep_reg->gpm4dat |= 0x1 ;
				break ;
		case 1 :
				printk(KERN_EMERG"led2_on\n");
				led_reg->gpm4dat &= ~(1<<1) ;
				//beep_reg->gpm4dat |= 0x1 ;
				beep_reg->gpm4dat &=~0x1 ; //蜂鸣器不响
				break ;
		case 2 :
				printk(KERN_EMERG"led3_on\n");
				led_reg->gpm4dat &= ~(1<<2) ;
				beep_reg->gpm4dat |= 0x1 ;
				break ;
		case 3 :
				printk(KERN_EMERG"ledall_off\n");
				led_reg->gpm4dat |= ((1<<0) | (1<<1) |(1<<2)| (1<<3)) ;
				beep_reg->gpm4dat &=~0x1 ;
				break ;
		case 4 :
				printk(KERN_EMERG"ledall_on\n");
				led_reg->gpm4dat &=~ ((1<<0) | (1<<1) |(1<<2)| (1<<3)) ;
				beep_reg->gpm4dat &=~0x1 ;
				break ;
		case 5 : 
				printk(KERN_EMERG"ledall_off\n");
				led_reg->gpm4dat |= ((1<<0) | (1<<1) |(1<<2)| (1<<3)) ;
				beep_reg->gpm4dat |= 0x1 ;
				break ;

	}
	return 0;
}
int poll_drv_close(struct inode *inode, struct file *file)
{
	printk("poll_close\n");
	led_reg->gpm4dat |= (1<<0) | (1<<1) | (1<<2) | (1<<3);  //全灭,因为高电平是灭的，0xf ----> 1111
	//关闭蜂鸣器 
	beep_reg->gpm4dat &= ~0x1 ;
	free_irq(IRQ_EINT(26), "k1");
	free_irq(IRQ_EINT(27), "k2");
	free_irq(IRQ_EINT(28), "k3");
	free_irq(IRQ_EINT(29), "k4");
	return 0;
}

static unsigned poll_drv_poll(struct file *file, poll_table *wait)
{
	unsigned int mask = 0;
	poll_wait(file, &button_waitq, wait); // 不会立即休眠

	if (ev_press)
		mask |= POLLIN | POLLRDNORM;

	return mask;
}



static struct file_operations sencod_drv_fops = {
    .owner   =  THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */
    .open    =  poll_drv_open,     
	.read	 =	poll_drv_read,	   
	.release =  poll_drv_close,
	.poll    =  poll_drv_poll,
	.write = poll_drv_write,
};



static int poll_drv_init(void)
{
	major = register_chrdev(0, DEV_NAME, &sencod_drv_fops);

	polldrv_class = class_create(THIS_MODULE, DEV_NAME);

	polldrv_class_dev = device_create(polldrv_class, NULL, MKDEV(major, 0), NULL, DEV_NAME); /* /dev/buttons */

	led_reg = ioremap(0x110002e0, sizeof(struct led_reg));
	beep_reg = ioremap(0x114000A0, sizeof(struct beep_reg));
	key_reg = ioremap(0x11000C60, sizeof(struct key_reg));
	
	return 0;
}

static void poll_drv_exit(void)
{
	printk("poll_exit\n");
	unregister_chrdev(major, "poll_drv");
	device_destroy(polldrv_class, MKDEV(major, 0));
	class_destroy(polldrv_class);
	
	iounmap(led_reg);
	iounmap(beep_reg);
	iounmap(key_reg);
}


module_init(poll_drv_init);

module_exit(poll_drv_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("hai");
MODULE_VERSION("2017.5.2");