基於tiny210v2的linux-3.9.6內核驅動移植2:按鍵驅動

   終於放假了，可以好好玩我的210了。
   這次進行buttons的移植。
   環境：ubuntu
   移植內核版本：linux-3.9.6
   參考友善提供的linux-3.0.8
一、主要代碼
    在drivers/char目錄下新建smdkv210_buttons.c
    代碼：

  

/*
 * linux/drivers/char/smdkv210_buttons.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/irq.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <mach/hardware.h>
#include <linux/platform_device.h>
#include <linux/cdev.h>
#include <linux/miscdevice.h>

#include <mach/map.h>
#include <mach/gpio.h>
#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>

#define DEVICE_NAME		"buttons"

struct button_desc {
	int gpio;
	int number;
	char *name;	
	struct timer_list timer;
};

static struct button_desc buttons[] = {
	{ S5PV210_GPH2(0), 0, "KEY0" },
	{ S5PV210_GPH2(1), 1, "KEY1" },
	{ S5PV210_GPH2(2), 2, "KEY2" },
	{ S5PV210_GPH2(3), 3, "KEY3" },
	{ S5PV210_GPH3(0), 4, "KEY4" },
	{ S5PV210_GPH3(1), 5, "KEY5" },
	{ S5PV210_GPH3(2), 6, "KEY6" },
	{ S5PV210_GPH3(3), 7, "KEY7" },
};

static volatile char key_values[] = {
	'0', '0', '0', '0', '0', '0', '0', '0'
};

static DECLARE_WAIT_QUEUE_HEAD(button_waitq);

static volatile int ev_press = 0;

static void smdkv210_buttons_timer(unsigned long _data)
{
	struct button_desc *bdata = (struct button_desc *)_data;
	int down;
	int number;
	unsigned tmp;

	tmp = gpio_get_value(bdata->gpio);

	/* active low */
	down = !tmp;
	printk("KEY %d: %08x\n", bdata->number, down);

	number = bdata->number;
	if (down != (key_values[number] & 1)) {
		key_values[number] = '0' + down;

		ev_press = 1;
		wake_up_interruptible(&button_waitq);
	}
}

static irqreturn_t button_interrupt(int irq, void *dev_id)
{
	struct button_desc *bdata = (struct button_desc *)dev_id;

	mod_timer(&bdata->timer, jiffies + msecs_to_jiffies(40));

	return IRQ_HANDLED;
}

static int smdkv210_buttons_open(struct inode *inode, struct file *file)
{
	int irq;
	int i;
	int err = 0;

	for (i = 0; i < ARRAY_SIZE(buttons); i++) {
		if (!buttons[i].gpio)
			continue;

		setup_timer(&buttons[i].timer, smdkv210_buttons_timer,
				(unsigned long)&buttons[i]);

		irq = gpio_to_irq(buttons[i].gpio);
		err = request_irq(irq, button_interrupt, IRQ_TYPE_EDGE_BOTH, 
				buttons[i].name, (void *)&buttons[i]);
		if (err)
			break;
	}

	if (err) {
		i--;
		for (; i >= 0; i--) {
			if (!buttons[i].gpio)
				continue;

			irq = gpio_to_irq(buttons[i].gpio);
			disable_irq(irq);
			free_irq(irq, (void *)&buttons[i]);

			del_timer_sync(&buttons[i].timer);
		}

		return -EBUSY;
	}

	ev_press = 1;
	return 0;
}

static int smdkv210_buttons_close(struct inode *inode, struct file *file)
{
	int irq, i;

	for (i = 0; i < ARRAY_SIZE(buttons); i++) {
		if (!buttons[i].gpio)
			continue;

		irq = gpio_to_irq(buttons[i].gpio);
		free_irq(irq, (void *)&buttons[i]);

		del_timer_sync(&buttons[i].timer);
	}

	return 0;
}

static int smdkv210_buttons_read(struct file *filp, char __user *buff,
		size_t count, loff_t *offp)
{
	unsigned long err;

	if (!ev_press) {
		if (filp->f_flags & O_NONBLOCK)
			return -EAGAIN;
		else
			wait_event_interruptible(button_waitq, ev_press);
	}

	ev_press = 0;

	err = copy_to_user((void *)buff, (const void *)(&key_values),
			min(sizeof(key_values), count));

	return err ? -EFAULT : min(sizeof(key_values), count);
}

static unsigned int smdkv210_buttons_poll( struct file *file,
		struct poll_table_struct *wait)
{
	unsigned int mask = 0;

	poll_wait(file, &button_waitq, wait);
	if (ev_press)
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

static struct file_operations dev_fops = {
	.owner		= THIS_MODULE,
	.open		= smdkv210_buttons_open,
	.release	= smdkv210_buttons_close, 
	.read		= smdkv210_buttons_read,
	.poll		= smdkv210_buttons_poll,
};

static struct miscdevice misc = {
	.minor		= MISC_DYNAMIC_MINOR,
	.name		= DEVICE_NAME,
	.fops		= &dev_fops,
};

static int __init button_dev_init(void)
{
	int ret;

	ret = misc_register(&misc);

	printk(DEVICE_NAME"\tinitialized\n");

	return ret;
}

static void __exit button_dev_exit(void)
{
	misc_deregister(&misc);
}

module_init(button_dev_init);
module_exit(button_dev_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("FriendlyARM Inc.");

修改該目錄下的Kconfig
添加：
  config SMDKV210_BUTTONS
    tristate"Buttons driver for FriendlyARM Mini210 development boards"
    depends onCPU_S5PV210 && !KEYBOARD_GPIO
    default y if!KEYBOARD_GPIO
    help
     this is buttons driver for FriendlyARM TINY210development boards
Makefile添加：
 obj-$(CONFIG_SMDKV210_BUTTONS)   += smdkv210_buttons.o 
測試程序：
  

#include<stdio.h>
 #include<stdlib.h>
 #include<unistd.h>
 #include<sys/ioctl.h>
 #include<sys/types.h>
 #include<sys/stat.h>
 #include<fcntl.h>
 #include<sys/select.h>
 #include<sys/time.h>
 #include<errno.h>
 int main(void)
  {
   int buttons_fd;
   char buttons[6]= {'0','0', '0', '0','0', '0'};
   buttons_fd= open("/dev/buttons",0);
    if(buttons_fd< 0) {
       perror("opendevice buttons");
    exit(1);
    }
     for (;;){
    charcurrent_buttons[6];
    intcount_of_changed_key;
    inti;
    if(read(buttons_fd,current_buttons,sizeofcurrent_buttons)！=sizeof current_buttons){
    perror("readbuttons:");
    exit(1);
     }
     for(i= 0,count_of_changed_key = 0; i< sizeofbuttons / sizeofbuttons[0];i++) {
    if (buttons[i]!= current_buttons[i]){
       buttons[i]=current_buttons[i];
       printf("%skey%d is %s",count_of_changed_key?", ": "", i+1,buttons[i] =='0'? "up" : "down");
    count_of_changed_key++;
    }
    }
    if(count_of_changed_key){
      printf("\n");
    }
    }
     close(buttons_fd);
      return0;
     }