目录

• LED驱动的移植
• • first_drv.c
  • firstdrvtest.c
• 按键驱动的移植
• • second_drv.c
  • seconddrvtest.c
• 休眠按键驱动
• • third_drv.c
  • thirddrvtest.c
• poll机制按键驱动
• • forth_drv.c
  • forthdrvtest.c
• 异步机制按键驱动
• • fifth_drv.c
  • fifthdrvtest.c
• 互斥锁机制按键驱动
• • sixth_drv.c
  • sixthdrvtest.c
• 定时器按键驱动
• • buttons.c
  • buttons_test.c

本文是基于韦东山视频的学习笔记

汇总点这

以下的移植过程都大同小异，都是先把Makefile文件中的内核编译路径改为自己的3.4.2的内核编译路径（内核要成功编译过），直接make根据错误信息修改错误。

LED驱动的移植

• 需要去掉头文件<asm/hardware.h>，把<asm/arch/regs-gpio.h>给成<mach/regs-gpio.h>，加上头文件<linux/device.h>
• 把class_device_create改成device_create，同样的需要把class_device_unregister改成device_unregister

first_drv.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/device.h>

//#include <asm/arch/regs-gpio.h>
//#include <asm/hardware.h>

static struct class *firstdrv_class;
static struct class_device	*firstdrv_class_dev;

volatile unsigned long *gpfcon = NULL;
volatile unsigned long *gpfdat = NULL;


static int first_drv_open(struct inode *inode, struct file *file)
{
	//printk("first_drv_open\n");
	/* 配置GPF4,5,6为输出 */
	*gpfcon &= ~((0x3<<(4*2)) | (0x3<<(5*2)) | (0x3<<(6*2)));
	*gpfcon |= ((0x1<<(4*2)) | (0x1<<(5*2)) | (0x1<<(6*2)));
	return 0;
}

static ssize_t first_drv_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
{
	int val;

	//printk("first_drv_write\n");

	copy_from_user(&val, buf, count); //	copy_to_user();

	if (val == 1)
	{
		// 点灯
		*gpfdat &= ~((1<<4) | (1<<5) | (1<<6));
	}
	else
	{
		// 灭灯
		*gpfdat |= (1<<4) | (1<<5) | (1<<6);
	}
	
	return 0;
}

static struct file_operations first_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   =   first_drv_open,     
	.write	=	first_drv_write,	   
};


int major;
static int first_drv_init(void)
{
	major = register_chrdev(0, "first_drv", &first_drv_fops); // 注册, 告诉内核

	firstdrv_class = class_create(THIS_MODULE, "firstdrv");

	firstdrv_class_dev = device_create(firstdrv_class, NULL, MKDEV(major, 0), NULL, "xyz"); /* /dev/xyz */

	gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
	gpfdat = gpfcon + 1;

	return 0;
}

static void first_drv_exit(void)
{
	unregister_chrdev(major, "first_drv"); // 卸载

	device_destroy(firstdrv_class, MKDEV(major, 0));
	class_destroy(firstdrv_class);
	iounmap(gpfcon);
}

module_init(first_drv_init);
module_exit(first_drv_exit);


MODULE_LICENSE("GPL");

firstdrvtest.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>

/* firstdrvtest on
  * firstdrvtest off
  */
int main(int argc, char **argv)
{
	int fd;
	int val = 1;
	fd = open("/dev/xyz", O_RDWR);
	if (fd < 0)
	{
		printf("can't open!\n");
	}
	if (argc != 2)
	{
		printf("Usage :\n");
		printf("%s <on|off>\n", argv[0]);
		return 0;
	}

	if (strcmp(argv[1], "on") == 0)
	{
		val  = 1;
	}
	else
	{
		val = 0;
	}
	
	write(fd, &val, 4);
	return 0;
}

按键驱动的移植

• 需要去掉头文件<asm/arch/regs-gpio.h>和<asm/hardware.h>，加上头文件<linux/device.h>
• 把class_device_create改成device_create，同样的需要把class_device_unregister改成device_unregister

second_drv.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/device.h>

//#include <asm/arch/regs-gpio.h>
//#include <asm/hardware.h>

static struct class *seconddrv_class;
static struct class_device	*seconddrv_class_dev;

volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;

volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;

static int second_drv_open(struct inode *inode, struct file *file)
{
	/* 配置GPF0,2为输入引脚 */
	*gpfcon &= ~((0x3<<(0*2)) | (0x3<<(2*2)));

	/* 配置GPG3,11为输入引脚 */
	*gpgcon &= ~((0x3<<(3*2)) | (0x3<<(11*2)));

	return 0;
}

ssize_t second_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
	/* 返回4个引脚的电平 */
	unsigned char key_vals[4];
	int regval;

	if (size != sizeof(key_vals))
		return -EINVAL;

	/* 读GPF0,2 */
	regval = *gpfdat;
	key_vals[0] = (regval & (1<<0)) ? 1 : 0;
	key_vals[1] = (regval & (1<<2)) ? 1 : 0;
	

	/* 读GPG3,11 */
	regval = *gpgdat;
	key_vals[2] = (regval & (1<<3)) ? 1 : 0;
	key_vals[3] = (regval & (1<<11)) ? 1 : 0;

	copy_to_user(buf, key_vals, sizeof(key_vals));
	
	return sizeof(key_vals);
}


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   =   second_drv_open,     
	.read	=	second_drv_read,	   
};


int major;
static int second_drv_init(void)
{
	major = register_chrdev(0, "second_drv", &sencod_drv_fops);

	seconddrv_class = class_create(THIS_MODULE, "second_drv");

	seconddrv_class_dev = device_create(seconddrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */

	gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
	gpfdat = gpfcon + 1;

	gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
	gpgdat = gpgcon + 1;

	return 0;
}

static void second_drv_exit(void)
{
	unregister_chrdev(major, "second_drv");
	device_destroy(seconddrv_class, MKDEV(major, 0));
	class_destroy(seconddrv_class);
	iounmap(gpfcon);
	iounmap(gpgcon);
	return 0;
}


module_init(second_drv_init);

module_exit(second_drv_exit);

MODULE_LICENSE("GPL");

seconddrvtest.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>

/* seconddrvtest 
  */
int main(int argc, char **argv)
{
	int fd;
	unsigned char key_vals[4];
	int cnt = 0;
	
	fd = open("/dev/buttons", O_RDWR);
	if (fd < 0)
	{
		printf("can't open!\n");
	}

	while (1)
	{
		read(fd, key_vals, sizeof(key_vals));
		if (!key_vals[0] || !key_vals[1] || !key_vals[2] || !key_vals[3])
		{
			printf("%04d key pressed: %d %d %d %d\n", cnt++, key_vals[0], key_vals[1], key_vals[2], key_vals[3]);
		}
	}
	
	return 0;
}

休眠按键驱动

• 需要增改的头文件

• • #include <linux/device.h>
    #include <mach/regs-gpio.h>
    #include <mach/gpio.h>
    #include <linux/sched.h>
    #include <linux/interrupt.h>

• S3C2410_GPF 无定义问题，在Documentation/arm/Samsung-S3C24XX/GPIO.txt里面提到修改了用法

• • Configuring a pin：
    The following function allows the configuration of a given pin to
    be changed.
    void s3c2410_gpio_cfgpin(unsigned int pin, unsigned int function);
    Eg:
    s3c2410_gpio_cfgpin(S3C2410_GPA(0), S3C2410_GPA0_ADDR0); s3c2410_gpio_cfgpin(S3C2410_GPE(8), S3C2410_GPE8_SDDAT1);
    which would turn GPA(0) into the lowest Address line A0, and set
    GPE(8) to be connected to the SDIO/MMC controller’s SDDAT1 line.
    The s3c_gpio_cfgpin() call is a functional replacement for this call.

• TASK_INTERRUPTIBLE 在新内核取消了这种宏定义，修改为(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)

third_drv.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/device.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
//#include <asm/hardware.h>


static struct class *thirddrv_class;
static struct class_device	*thirddrv_class_dev;

volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;

volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;


static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

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


struct pin_desc{
	unsigned int pin;
	unsigned int key_val;
};


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

struct pin_desc pins_desc[4] = {
	{S3C2410_GPF(0), 0x01},
	{S3C2410_GPF(2), 0x02},
	{S3C2410_GPG(3), 0x03},
	{S3C2410_GPG(11), 0x04},
};


/*
  * 确定按键值
  */
static irqreturn_t buttons_irq(int irq, void *dev_id)
{
	struct pin_desc * pindesc = (struct pin_desc *)dev_id;
	unsigned int pinval;
	
	pinval = s3c2410_gpio_getpin(pindesc->pin);

	if (pinval)
	{
		/* 松开 */
		key_val = 0x80 | pindesc->key_val;
	}
	else
	{
		/* 按下 */
		key_val = pindesc->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 third_drv_open(struct inode *inode, struct file *file)
{
	/* 配置GPF0,2为输入引脚 */
	/* 配置GPG3,11为输入引脚 */
	request_irq(IRQ_EINT0,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S2", &pins_desc[0]);
	request_irq(IRQ_EINT2,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S3", &pins_desc[1]);
	request_irq(IRQ_EINT11, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S4", &pins_desc[2]);
	request_irq(IRQ_EINT19, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S5", &pins_desc[3]);	

	return 0;
}

ssize_t third_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);
	ev_press = 0;
	
	return 1;
}


int third_drv_close(struct inode *inode, struct file *file)
{
	free_irq(IRQ_EINT0, &pins_desc[0]);
	free_irq(IRQ_EINT2, &pins_desc[1]);
	free_irq(IRQ_EINT11, &pins_desc[2]);
	free_irq(IRQ_EINT19, &pins_desc[3]);
	return 0;
}


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    =  third_drv_open,     
	.read	 =	third_drv_read,	   
	.release =  third_drv_close,	   
};


int major;
static int third_drv_init(void)
{
	major = register_chrdev(0, "third_drv", &sencod_drv_fops);

	thirddrv_class = class_create(THIS_MODULE, "third_drv");

	thirddrv_class_dev = device_create(thirddrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */

	gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
	gpfdat = gpfcon + 1;

	gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
	gpgdat = gpgcon + 1;

	return 0;
}

static void third_drv_exit(void)
{
	unregister_chrdev(major, "third_drv");
	device_destroy(thirddrv_class, MKDEV(major, 0));
	class_destroy(thirddrv_class);
	iounmap(gpfcon);
	iounmap(gpgcon);
	return 0;
}


module_init(third_drv_init);

module_exit(third_drv_exit);

MODULE_LICENSE("GPL");

thirddrvtest.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

/* thirddrvtest 
  */
int main(int argc, char **argv)
{
	int fd;
	unsigned char key_val;
	
	fd = open("/dev/buttons", O_RDWR);
	if (fd < 0)
	{
		printf("can't open!\n");
	}

	while (1)
	{
		read(fd, &key_val, 1);
		printf("key_val = 0x%x\n", key_val);
	}
	
	return 0;
}

poll机制按键驱动

• 需要增改的头文件
• • #include <linux/poll.h>
    #include <linux/device.h>
    #include <mach/regs-gpio.h>
    #include <mach/gpio.h>
    #include <linux/sched.h>
    #include <linux/interrupt.h>
    //#include <asm/hardware.h>
• TASK_INTERRUPTIBLE 在新内核取消了这种宏定义，修改为(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)

forth_drv.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>

#include <linux/poll.h>
#include <linux/device.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
//#include <asm/hardware.h>


static struct class *forthdrv_class;
static struct class_device	*forthdrv_class_dev;

volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;

volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;


static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

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


struct pin_desc{
	unsigned int pin;
	unsigned int key_val;
};


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

struct pin_desc pins_desc[4] = {
	{S3C2410_GPF(0), 0x01},
	{S3C2410_GPF(2), 0x02},
	{S3C2410_GPG(3), 0x03},
	{S3C2410_GPG(11), 0x04},
};



/*
  * 确定按键值
  */
static irqreturn_t buttons_irq(int irq, void *dev_id)
{
	struct pin_desc * pindesc = (struct pin_desc *)dev_id;
	unsigned int pinval;
	
	pinval = s3c2410_gpio_getpin(pindesc->pin);

	if (pinval)
	{
		/* 松开 */
		key_val = 0x80 | pindesc->key_val;
	}
	else
	{
		/* 按下 */
		key_val = pindesc->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 forth_drv_open(struct inode *inode, struct file *file)
{
	/* 配置GPF0,2为输入引脚 */
	/* 配置GPG3,11为输入引脚 */
	request_irq(IRQ_EINT0,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S2", &pins_desc[0]);
	request_irq(IRQ_EINT2,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S3", &pins_desc[1]);
	request_irq(IRQ_EINT11, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S4", &pins_desc[2]);
	request_irq(IRQ_EINT19, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S5", &pins_desc[3]);	

	return 0;
}

ssize_t forth_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);
	ev_press = 0;
	
	return 1;
}


int forth_drv_close(struct inode *inode, struct file *file)
{
	free_irq(IRQ_EINT0, &pins_desc[0]);
	free_irq(IRQ_EINT2, &pins_desc[1]);
	free_irq(IRQ_EINT11, &pins_desc[2]);
	free_irq(IRQ_EINT19, &pins_desc[3]);
	return 0;
}

static unsigned forth_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    =  forth_drv_open,     
	.read	 =	forth_drv_read,	   
	.release =  forth_drv_close,
	.poll    =  forth_drv_poll,
};


int major;
static int forth_drv_init(void)
{
	major = register_chrdev(0, "forth_drv", &sencod_drv_fops);

	forthdrv_class = class_create(THIS_MODULE, "forth_drv");

	forthdrv_class_dev = device_create(forthdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */

	gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
	gpfdat = gpfcon + 1;

	gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
	gpgdat = gpgcon + 1;

	return 0;
}

static void forth_drv_exit(void)
{
	unregister_chrdev(major, "forth_drv");
	device_destroy(forthdrv_class, MKDEV(major, 0));
	class_destroy(forthdrv_class);
	iounmap(gpfcon);
	iounmap(gpgcon);
	return 0;
}


module_init(forth_drv_init);

module_exit(forth_drv_exit);

MODULE_LICENSE("GPL");

forthdrvtest.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>


/* forthdrvtest 
  */
int main(int argc, char **argv)
{
	int fd;
	unsigned char key_val;
	int ret;

	struct pollfd fds[1];
	
	fd = open("/dev/buttons", O_RDWR);
	if (fd < 0)
	{
		printf("can't open!\n");
	}

	fds[0].fd     = fd;
	fds[0].events = POLLIN;
	while (1)
	{
		ret = poll(fds, 1, 5000);
		if (ret == 0)
		{
			printf("time out\n");
		}
		else
		{
			read(fd, &key_val, 1);
			printf("key_val = 0x%x\n", key_val);
		}
	}
	
	return 0;
}

异步机制按键驱动

移植与poll机制按键驱动大同小异

• 需要增改的头文件
• • #include <linux/poll.h>
    #include <linux/device.h>
    #include <mach/regs-gpio.h>
    #include <mach/gpio.h>
    #include <linux/sched.h>
    #include <linux/interrupt.h>
    //#include <asm/hardware.h>
• TASK_INTERRUPTIBLE 在新内核取消了这种宏定义，修改为(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)

fifth_drv.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/poll.h>

#include <linux/poll.h>
#include <linux/device.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>
#include <linux/sched.h>
#include <linux/interrupt.h>

static struct class *fifthdrv_class;
static struct class_device	*fifthdrv_class_dev;

volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;

volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;


static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

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

static struct fasync_struct *button_async;


struct pin_desc{
	unsigned int pin;
	unsigned int key_val;
};


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

struct pin_desc pins_desc[4] = {
	{S3C2410_GPF(0), 0x01},
	{S3C2410_GPF(2), 0x02},
	{S3C2410_GPG(3), 0x03},
	{S3C2410_GPG(11), 0x04},
};


/*
  * 确定按键值
  */
static irqreturn_t buttons_irq(int irq, void *dev_id)
{
	struct pin_desc * pindesc = (struct pin_desc *)dev_id;
	unsigned int pinval;
	
	pinval = s3c2410_gpio_getpin(pindesc->pin);

	if (pinval)
	{
		/* 松开 */
		key_val = 0x80 | pindesc->key_val;
	}
	else
	{
		/* 按下 */
		key_val = pindesc->key_val;
	}

    ev_press = 1;                  /* 表示中断发生了 */
    wake_up_interruptible(&button_waitq);   /* 唤醒休眠的进程 */
	
	kill_fasync (&button_async, SIGIO, POLL_IN);
	
	return IRQ_RETVAL(IRQ_HANDLED);
}

static int fifth_drv_open(struct inode *inode, struct file *file)
{
	/* 配置GPF0,2为输入引脚 */
	/* 配置GPG3,11为输入引脚 */
	request_irq(IRQ_EINT0,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S2", &pins_desc[0]);
	request_irq(IRQ_EINT2,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S3", &pins_desc[1]);
	request_irq(IRQ_EINT11, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S4", &pins_desc[2]);
	request_irq(IRQ_EINT19, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S5", &pins_desc[3]);	

	return 0;
}

ssize_t fifth_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);
	ev_press = 0;
	
	return 1;
}


int fifth_drv_close(struct inode *inode, struct file *file)
{
	free_irq(IRQ_EINT0, &pins_desc[0]);
	free_irq(IRQ_EINT2, &pins_desc[1]);
	free_irq(IRQ_EINT11, &pins_desc[2]);
	free_irq(IRQ_EINT19, &pins_desc[3]);
	return 0;
}

static unsigned fifth_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 int fifth_drv_fasync (int fd, struct file *filp, int on)
{
	printk("driver: fifth_drv_fasync\n");
	return fasync_helper (fd, filp, on, &button_async);
}


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    =  fifth_drv_open,     
	.read	 =	fifth_drv_read,	   
	.release =  fifth_drv_close,
	.poll    =  fifth_drv_poll,
	.fasync	 =  fifth_drv_fasync,
};


int major;
static int fifth_drv_init(void)
{
	major = register_chrdev(0, "fifth_drv", &sencod_drv_fops);

	fifthdrv_class = class_create(THIS_MODULE, "fifth_drv");

	fifthdrv_class_dev = device_create(fifthdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */

	gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
	gpfdat = gpfcon + 1;

	gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
	gpgdat = gpgcon + 1;

	return 0;
}

static void fifth_drv_exit(void)
{
	unregister_chrdev(major, "fifth_drv");
	device_destroy(fifthdrv_class, MKDEV(major, 0));
	class_destroy(fifthdrv_class);
	iounmap(gpfcon);
	iounmap(gpgcon);
	return 0;
}


module_init(fifth_drv_init);

module_exit(fifth_drv_exit);

MODULE_LICENSE("GPL");

fifthdrvtest.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>


/* fifthdrvtest 
  */
int fd;

void my_signal_fun(int signum)
{
	unsigned char key_val;
	read(fd, &key_val, 1);
	printf("key_val: 0x%x\n", key_val);
}

int main(int argc, char **argv)
{
	unsigned char key_val;
	int ret;
	int Oflags;

	signal(SIGIO, my_signal_fun);
	
	fd = open("/dev/buttons", O_RDWR);
	if (fd < 0)
	{
		printf("can't open!\n");
	}

	fcntl(fd, F_SETOWN, getpid());
	
	Oflags = fcntl(fd, F_GETFL); 
	
	fcntl(fd, F_SETFL, Oflags | FASYNC);


	while (1)
	{
		sleep(1000);
	}
	
	return 0;
}

互斥锁机制按键驱动

• 需要增改的头文件
• • #include <linux/poll.h>
    #include <linux/device.h>
    #include <mach/regs-gpio.h>
    #include <mach/gpio.h>
    #include <linux/sched.h>
    #include <linux/interrupt.h>
    //#include <asm/hardware.h>
• TASK_INTERRUPTIBLE 在新内核取消了这种宏定义，修改为(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)

除了这些外，定义互斥锁DECLARE_MUTEX这个宏定义已经取消了，需要重新定义和初始化struct semaphore button_lock; , sema_init(&button_lock, 1);

sixth_drv.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/poll.h>

#include <linux/poll.h>
#include <linux/device.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>
#include <linux/sched.h>
#include <linux/interrupt.h>


static struct class *sixthdrv_class;
static struct class_device	*sixthdrv_class_dev;

volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;

volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;


static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

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

static struct fasync_struct *button_async;


struct pin_desc{
	unsigned int pin;
	unsigned int key_val;
};


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

struct pin_desc pins_desc[4] = {
	{S3C2410_GPF(0), 0x01},
	{S3C2410_GPF(2), 0x02},
	{S3C2410_GPG(3), 0x03},
	{S3C2410_GPG(11), 0x04},
};


//static atomic_t canopen = ATOMIC_INIT(1);     //定义原子变量并初始化为1

//static DECLARE_MUTEX(button_lock);     //定义互斥锁
struct semaphore button_lock;


/*
  * 确定按键值
  */
static irqreturn_t buttons_irq(int irq, void *dev_id)
{
	struct pin_desc * pindesc = (struct pin_desc *)dev_id;
	unsigned int pinval;
	
	pinval = s3c2410_gpio_getpin(pindesc->pin);

	if (pinval)
	{
		/* 松开 */
		key_val = 0x80 | pindesc->key_val;
	}
	else
	{
		/* 按下 */
		key_val = pindesc->key_val;
	}

    ev_press = 1;                  /* 表示中断发生了 */
    wake_up_interruptible(&button_waitq);   /* 唤醒休眠的进程 */
	
	kill_fasync (&button_async, SIGIO, POLL_IN);
	
	return IRQ_RETVAL(IRQ_HANDLED);
}

static int sixth_drv_open(struct inode *inode, struct file *file)
{
#if 0	
	if (!atomic_dec_and_test(&canopen))
	{
		atomic_inc(&canopen);
		return -EBUSY;
	}
#endif		

	if (file->f_flags & O_NONBLOCK)
	{
		if (down_trylock(&button_lock))
			return -EBUSY;
	}
	else
	{
		/* 获取信号量 */
		down(&button_lock);
	}

	/* 配置GPF0,2为输入引脚 */
	/* 配置GPG3,11为输入引脚 */
	request_irq(IRQ_EINT0,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S2", &pins_desc[0]);
	request_irq(IRQ_EINT2,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S3", &pins_desc[1]);
	request_irq(IRQ_EINT11, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S4", &pins_desc[2]);
	request_irq(IRQ_EINT19, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S5", &pins_desc[3]);	

	return 0;
}

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

	if (file->f_flags & O_NONBLOCK)
	{
		if (!ev_press)
			return -EAGAIN;
	}
	else
	{
		/* 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);
	ev_press = 0;
	
	return 1;
}


int sixth_drv_close(struct inode *inode, struct file *file)
{
	//atomic_inc(&canopen);
	free_irq(IRQ_EINT0, &pins_desc[0]);
	free_irq(IRQ_EINT2, &pins_desc[1]);
	free_irq(IRQ_EINT11, &pins_desc[2]);
	free_irq(IRQ_EINT19, &pins_desc[3]);
	up(&button_lock);
	return 0;
}

static unsigned sixth_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 int sixth_drv_fasync (int fd, struct file *filp, int on)
{
	printk("driver: sixth_drv_fasync\n");
	return fasync_helper (fd, filp, on, &button_async);
}


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    =  sixth_drv_open,     
	.read	 =	sixth_drv_read,	   
	.release =  sixth_drv_close,
	.poll    =  sixth_drv_poll,
	.fasync	 =  sixth_drv_fasync,
};


int major;
static int sixth_drv_init(void)
{
	major = register_chrdev(0, "sixth_drv", &sencod_drv_fops);

	sixthdrv_class = class_create(THIS_MODULE, "sixth_drv");

	sixthdrv_class_dev = device_create(sixthdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */

	gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
	gpfdat = gpfcon + 1;

	gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
	gpgdat = gpgcon + 1;

	sema_init(&button_lock, 1);
	return 0;
}

static void sixth_drv_exit(void)
{
	unregister_chrdev(major, "sixth_drv");
	device_destroy(sixthdrv_class, MKDEV(major, 0));
	class_destroy(sixthdrv_class);
	iounmap(gpfcon);
	iounmap(gpgcon);
	return 0;
}


module_init(sixth_drv_init);

module_exit(sixth_drv_exit);

MODULE_LICENSE("GPL");

sixthdrvtest.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>


/* sixthdrvtest 
  */
int fd;

void my_signal_fun(int signum)
{
	unsigned char key_val;
	read(fd, &key_val, 1);
	printf("key_val: 0x%x\n", key_val);
}

int main(int argc, char **argv)
{
	unsigned char key_val;
	int ret;
	int Oflags;

	//signal(SIGIO, my_signal_fun);
	
	fd = open("/dev/buttons", O_RDWR | O_NONBLOCK);
	if (fd < 0)
	{
		printf("can't open!\n");
		return -1;
	}

	//fcntl(fd, F_SETOWN, getpid());
	
	//Oflags = fcntl(fd, F_GETFL); 
	
	//fcntl(fd, F_SETFL, Oflags | FASYNC);


	while (1)
	{
		ret = read(fd, &key_val, 1);
		printf("key_val: 0x%x, ret = %d\n", key_val, ret);
		sleep(5);
	}
	
	return 0;
}

定时器按键驱动

修改的东西和前面一样

buttons.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/poll.h>

#include <linux/poll.h>
#include <linux/device.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>
#include <linux/sched.h>
#include <linux/interrupt.h>


static struct class *sixthdrv_class;
static struct class_device	*sixthdrv_class_dev;

volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;

volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;

static struct timer_list buttons_timer;


static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

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

static struct fasync_struct *button_async;


struct pin_desc{
	unsigned int pin;
	unsigned int key_val;
};


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

struct pin_desc pins_desc[4] = {
	{S3C2410_GPF(0), 0x01},
	{S3C2410_GPF(2), 0x02},
	{S3C2410_GPG(3), 0x03},
	{S3C2410_GPG(11), 0x04},
};

static struct pin_desc *irq_pd;

//static atomic_t canopen = ATOMIC_INIT(1);     //定义原子变量并初始化为1

//static DECLARE_MUTEX(button_lock);     //定义互斥锁
struct semaphore button_lock;


/*
  * 确定按键值
  */
static irqreturn_t buttons_irq(int irq, void *dev_id)
{
	/* 10ms后启动定时器 */
	irq_pd = (struct pin_desc *)dev_id;
	mod_timer(&buttons_timer, jiffies+HZ/100);
	return IRQ_RETVAL(IRQ_HANDLED);
}

static int sixth_drv_open(struct inode *inode, struct file *file)
{
#if 0	
	if (!atomic_dec_and_test(&canopen))
	{
		atomic_inc(&canopen);
		return -EBUSY;
	}
#endif		

	if (file->f_flags & O_NONBLOCK)
	{
		if (down_trylock(&button_lock))
			return -EBUSY;
	}
	else
	{
		/* 获取信号量 */
		down(&button_lock);
	}

	/* 配置GPF0,2为输入引脚 */
	/* 配置GPG3,11为输入引脚 */
	request_irq(IRQ_EINT0,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S2", &pins_desc[0]);
	request_irq(IRQ_EINT2,  buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S3", &pins_desc[1]);
	request_irq(IRQ_EINT11, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S4", &pins_desc[2]);
	request_irq(IRQ_EINT19, buttons_irq, (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING), "S5", &pins_desc[3]);	

	return 0;
}

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

	if (file->f_flags & O_NONBLOCK)
	{
		if (!ev_press)
			return -EAGAIN;
	}
	else
	{
		/* 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);
	ev_press = 0;
	
	return 1;
}


int sixth_drv_close(struct inode *inode, struct file *file)
{
	//atomic_inc(&canopen);
	free_irq(IRQ_EINT0, &pins_desc[0]);
	free_irq(IRQ_EINT2, &pins_desc[1]);
	free_irq(IRQ_EINT11, &pins_desc[2]);
	free_irq(IRQ_EINT19, &pins_desc[3]);
	up(&button_lock);
	return 0;
}

static unsigned sixth_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 int sixth_drv_fasync (int fd, struct file *filp, int on)
{
	printk("driver: sixth_drv_fasync\n");
	return fasync_helper (fd, filp, on, &button_async);
}


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    =  sixth_drv_open,     
	.read	 =	sixth_drv_read,	   
	.release =  sixth_drv_close,
	.poll    =  sixth_drv_poll,
	.fasync	 =  sixth_drv_fasync,
};


int major;

static void buttons_timer_function(unsigned long data)
{
	struct pin_desc * pindesc = irq_pd;
	unsigned int pinval;

	if (!pindesc)
		return;
	
	pinval = s3c2410_gpio_getpin(pindesc->pin);

	if (pinval)
	{
		/* 松开 */
		key_val = 0x80 | pindesc->key_val;
	}
	else
	{
		/* 按下 */
		key_val = pindesc->key_val;
	}

    ev_press = 1;                  /* 表示中断发生了 */
    wake_up_interruptible(&button_waitq);   /* 唤醒休眠的进程 */
	
	kill_fasync (&button_async, SIGIO, POLL_IN);
}


static int sixth_drv_init(void)
{
	init_timer(&buttons_timer);
	buttons_timer.function = buttons_timer_function;
	//buttons_timer.expires  = 0;
	add_timer(&buttons_timer); 

	major = register_chrdev(0, "sixth_drv", &sencod_drv_fops);

	sixthdrv_class = class_create(THIS_MODULE, "sixth_drv");

	/* 为了让mdev根据这些信息来创建设备节点 */
	sixthdrv_class_dev = device_create(sixthdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */

	gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
	gpfdat = gpfcon + 1;

	gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
	gpgdat = gpgcon + 1;
	
	sema_init(&button_lock, 1);

	return 0;
}

static void sixth_drv_exit(void)
{
	unregister_chrdev(major, "sixth_drv");
	device_destroy(sixthdrv_class, MKDEV(major, 0));
	class_destroy(sixthdrv_class);
	iounmap(gpfcon);
	iounmap(gpgcon);
	return 0;
}


module_init(sixth_drv_init);

module_exit(sixth_drv_exit);

MODULE_LICENSE("GPL");

buttons_test.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>


/* sixthdrvtest 
  */
int fd;

void my_signal_fun(int signum)
{
	unsigned char key_val;
	read(fd, &key_val, 1);
	printf("key_val: 0x%x\n", key_val);
}

int main(int argc, char **argv)
{
	unsigned char key_val;
	int ret;
	int Oflags;

	//signal(SIGIO, my_signal_fun);
	
	fd = open("/dev/buttons", O_RDWR);
	if (fd < 0)
	{
		printf("can't open!\n");
		return -1;
	}

	//fcntl(fd, F_SETOWN, getpid());
	
	//Oflags = fcntl(fd, F_GETFL); 
	
	//fcntl(fd, F_SETFL, Oflags | FASYNC);


	while (1)
	{
		ret = read(fd, &key_val, 1);
		printf("key_val: 0x%x, ret = %d\n", key_val, ret);
		//sleep(5);
	}
	
	return 0;
}