#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> 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;
}; struct key_desc key_desc[] = {
{IRQ_EINT0, S3C2410_GPF0, "K10", 1}, /* 鬆開: 1, 按下: 0x81 */
{IRQ_EINT2, S3C2410_GPF2, "K7", 2}, /* 鬆開: 2, 按下: 0x82 */
{IRQ_EINT11, S3C2410_GPG3, "K4", 3}, /* 鬆開: 3, 按下: 0x83 */
{IRQ_EINT19, S3C2410_GPG11, "K1", 4}, /* 鬆開: 4, 按下: 0x84 */
};
volatile char key = 0; static wait_queue_head_t
button_waitq; static irqreturn_t buttons_irq(int irq, void *dev_id)
{
struct key_desc *kd = (struct key_desc *)dev_id;
int up;
/* 確定按鍵: 哪個按鍵,按下還是鬆開 */
up = s3c2410_gpio_getpin(kd->pin); // gpfdat, gpgdat
if (up)
{
key = kd->key_val;
}
else
{
key = kd->key_val | 0x80;
} // printk("key = 0x%x\n", key); /* 喚醒應用程式 */
wake_up_interruptible(&button_waitq); printk("buttons_irq current %s , pid = %d \n", current->comm, current->pid);
return IRQ_HANDLED;
} int buttons_open(struct inode *inode, struct file *file)
{
int i;
/* 註冊中斷 */
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]);
} /* 設定GPIO為中斷引腳
* 設定觸發方式
* 使能中斷
*/ /* 設定KSCAN0(GPE11)為輸出引腳,輸出0 */
*gpecon &= ~(0x3 << 22);
*gpecon |= (1 << 22);
*gpedat &= ~(1<<11);
return 0;
} ssize_t buttons_read(struct file *inode, char __user *buf, size_t size, loff_t *offset)
{
/* 如果沒有按鍵發生, 休眠 */
/* key 等於 0, 才會休眠
* key 非0, 不會休眠
*/
// command
printk("current %s , pid = %d before sleep\n", current->comm, current->pid);
wait_event_interruptible(button_waitq,
key);/*key為等待事件，等待這個為真*/
printk("current %s , pid = %d after sleep\n", current->comm, current->pid); /* 被喚醒後, 把按索引值返回給使用者程式 */
copy_to_user(buf, &key, 1);
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 const struct file_operations buttons_fops = {
.owner = THIS_MODULE,
.read = buttons_read,
.open = buttons_open, /* 設定引腳,申請資源 */
.release = buttons_close,
}; int buttons_init(void)
{
int i;
major = register_chrdev(0, "buttons", &buttons_fops); /* sysfs ==> 掛接到/sys */
cls = class_create(THIS_MODULE, "buttons_class");
class_device_create(cls, NULL, MKDEV(major, 0), NULL, "buttons"); // mdev會根據/sys下的這些內容建立/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);
return 0;
} void buttons_exit(void)
{
unregister_chrdev(major, "buttons"); class_device_destroy(cls, MKDEV(major, 0));
class_destroy(cls); iounmap(gpecon);
} module_init(buttos_init);
module_exit(buttons_exit); MODULE_LICENSE("GPL"); |
