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#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <linux/interrupt.h>
#include <asm/mach/irq.h>
#include <asm/arch/regs-gpio.h>
#include <linux/poll.h>
static int major = 0;
static struct class *cls;
/* gpecon 0x56000040 */
/* gpfcon 0x56000050 */
/* gpgcon 0x56000060 */
static volatile unsigned long *gpecon;
static volatile unsigned long *gpedat;
static volatile unsigned long *gpfcon;
static volatile unsigned long *gpfdat;
static volatile unsigned long *gpgcon;
static volatile unsigned long *gpgdat;
struct key_desc {
int irq;
int pin;
char *name;
char key_val;
int irq_pin_val;
};
struct key_desc key_desc[] = {
{IRQ_EINT0, S3C2410_GPF0, "K10", 1}, /* 松开: 1, 按下: 0x81 */
{IRQ_EINT2, S3C2410_GPF2, "K7", 2}, /* 松开: 2, 按下: 0x82 */
{IRQ_EINT11, S3C2410_GPG3, "K4", 3}, /* 松开: 3, 按下: 0x83 */
{IRQ_EINT19, S3C2410_GPG11, "K1", 4}, /* 松开: 4, 按下: 0x84 */
};
volatile char key = 0;
static wait_queue_head_t button_waitq;
#define BUF_LEN 10
static char key_buf[BUF_LEN];
static volatile int r = 0, w = 0;
struct fasync_struct *buttons_async;
static struct timer_list buttons_timer;
struct key_desc *cur_kd;
static int isEmpty(void)
{
return (r == w);
}
static int isFull(void)
{
return (r == ((w+1)%BUF_LEN));
}
static int putData(char val)
{
if (isFull())
{
return -1;
}
else
{
key_buf[w] = val;
w = (w+1)%BUF_LEN;
return 0;
}
}
static int getData(char *p)
{
if (isEmpty())
{
return -1;
}
else
{
*p = key_buf[r];
r = (r+1)%BUF_LEN;
return 0;
}
}
static irqreturn_t buttons_irq(int irq, void *dev_id)
{
cur_kd = (struct key_desc *)dev_id;
cur_kd->irq_pin_val = s3c2410_gpio_getpin(cur_kd->pin);
mod_timer(&buttons_timer, jiffies+5);/*重置定时器*/
return IRQ_HANDLED;
}
static void buttons_timer_function(unsigned long data)
{
/* 确定按键: 哪个按键,按下还是松开 */
// for (i = 0; i < 10000; i++); /* 浪费CPU */
/* 启动一个定时器:
* 两要素:
* 1. 时间
* 2. 处理函数
*/
char key;
int up;
if (!cur_kd)
{
return;
}
up = s3c2410_gpio_getpin(cur_kd->pin); // gpfdat, gpgdat
if (up != cur_kd->irq_pin_val)
{
return;
}
if (up)
{
key = cur_kd->key_val;
}
else
{
key = cur_kd->key_val | 0x80;
}
// printk("key = 0x%x\n", key);
putData(key);
/* 唤醒应用程序 */
wake_up_interruptible(&button_waitq);
kill_fasync(&buttons_async, SIGIO, POLL_IN);
//printk("buttons_irq current %s , pid = %d \n", current->comm, current->pid);
}
int buttons_open(struct inode *inode, struct file *file)
{
int i;
/* 注册中断 */
for (i = 0; i < 4; i++)
{
request_irq(key_desc[i].irq, buttons_irq,
IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
key_desc[i].name, &key_desc[i]);
}
/* 设置GPIO为中断引脚
* 设置触发方式
* 使能中断
*/
/* 设置KSCAN0(GPE11)为输出引脚,输出0 */
*gpecon &= ~(0x3 << 22);
*gpecon |= (1 << 22);
*gpedat &= ~(1<<11);
return 0;
}
ssize_t buttons_read(struct file *file, char __user *buf, size_t size, loff_t *offset)
{
/* 如果没有按键发生, 休眠 */
/* key 等于 0, 才会休眠
* key 非0, 不会休眠
*/
// command
//printk("current %s , pid = %d before sleep\n", current->comm, current->pid);
char key;
if (isEmpty() && (file->f_flags & O_NONBLOCK))
return -EAGAIN;
wait_event_interruptible(button_waitq, !isEmpty());
//printk("current %s , pid = %d after sleep\n", current->comm, current->pid);
/* 被唤醒后, 把按键值返回给用户程序 */
getData(&key);
copy_to_user(buf, &key, 1);
/* 发生了中断, key=xxx */
//key = 0;
return 1;
}
int buttons_close(struct inode *inode, struct file *file)
{
int i;
for (i = 0; i < 4; i++)
{
free_irq(key_desc[i].irq, &key_desc[i]);
}
return 0;
}
static unsigned int buttons_poll(struct file *file, struct poll_table_struct *wait)
{
static int cnt = 0;
printk("buttons_poll cnt = %d\n", cnt++);
poll_wait(file, &button_waitq, wait); /* 不会休眠, 只是挂入队列 */
return isEmpty()? 0 : POLLIN | POLLRDNORM;
}
static int buttons_fasync(int fd, struct file *filp, int on)
{
int retval;
retval = fasync_helper(fd, filp, on, &buttons_async);
if (retval < 0)
return retval;
return 0;
}
static const struct file_operations buttons_fops = {
.owner = THIS_MODULE,
.read = buttons_read,
.open = buttons_open, /* 设置引脚,申请资源 */
.release = buttons_close,
.poll = buttons_poll,
.fasync = buttons_fasync,
};
int buttons_init(void)
{
int i;
major = register_chrdev(0, "buttons", &buttons_fops);
/* sysfs ==> 挂接到/sys */
cls = class_create(THIS_MODULE, "buttons_class");
class_device_create(cls, NULL, MKDEV(major, 0), NULL, "buttons");
// mdev会根据/sys下的这些内容创建/dev/buttons
gpecon = ioremap(0x56000040, 4096);
gpedat = gpecon + 1;
gpfcon = gpecon + 4;
gpfdat = gpfcon + 1;
gpgcon = gpecon + 8;
gpgdat = gpgcon + 1;
init_waitqueue_head(&button_waitq);
init_timer(&buttons_timer);
buttons_timer.function = buttons_timer_function;
buttons_timer.expires = 0;
add_timer(&buttons_timer);
return 0;
}
void buttons_exit(void)
{
unregister_chrdev(major, "buttons");
class_device_destroy(cls, MKDEV(major, 0));
class_destroy(cls);
iounmap(gpecon);
del_timer(&buttons_timer);
}
module_init(buttons_init);
module_exit(buttons_exit);
MODULE_LICENSE("GPL");
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