74hc165_button.c

几乎对所有开发板的按键都能用

/********************************************************************
 *       Filename:  74HC165_button.c
********************************************************************/

#include<linux/module.h>
#include<linux/config.h>
#include<linux/init.h>
#include<linux/fs.h>
#include<linux/timer.h>
#include<linux/ioctl.h>
#include<linux/io.h>
#include<linux/types.h>
#include<linux/kernel.h>
#include<linux/ioport.h>
#include<linux/errno.h>
#include<asm/uaccess.h>
#include "74HC165_button.h"

#define BUF_MAXSIZE 16
#define TIMER_DELAY 5

static  unsigned int  BReadBuf = 0;

//static  unsigned char chip_number = 1;
static  unsigned char chip_number = 2;

static  int delay(int time){
    while(--time);  
    return 0;
}

static  void button_read(void){
      int time;
      int val = 0,reg;
      //printk("button_read\n");
      /* CLK =0 */
      SOC3210_74HC165_READ(reg, SOC3210_74HC165_CLK);
      SOC3210_74HC165_WRITE(SOC3210_74HC165_CLK, reg & (~(1 << 0)));
      /* PL = 0 */
      SOC3210_74HC165_READ(reg, SOC3210_74HC165_PL);
      SOC3210_74HC165_WRITE(SOC3210_74HC165_PL, reg & ~(1 << 2));
      /* delay 100 */
      delay(10000);
      /* PL = 1 */
      SOC3210_74HC165_READ(reg, SOC3210_74HC165_PL);
      SOC3210_74HC165_WRITE(SOC3210_74HC165_PL, reg | (1 << 2));
      delay(10);
      SOC3210_74HC165_READ(reg, SOC3210_74HC165_DATA);
      val = ((~reg) & (1 << 1));
      BReadBuf = val >> 1;
      /* scanf keyboard */
      for(time = 1; time < 16; time ++){
      /* delay */
      delay(100);
      /* CLK = 1 */
      SOC3210_74HC165_READ(reg, SOC3210_74HC165_CLK);
      SOC3210_74HC165_WRITE(SOC3210_74HC165_CLK, reg | (1 << 0));
      delay(100);
      SOC3210_74HC165_READ(reg, SOC3210_74HC165_DATA);
      val = ((~reg) & (1 << 1));
      val = val >> 1;
      BReadBuf |= val << time;
      /* CLK = 0 */
      SOC3210_74HC165_READ(reg, SOC3210_74HC165_CLK);
      SOC3210_74HC165_WRITE(SOC3210_74HC165_CLK, reg & (~(1 << 0)));
      }
      if(BReadBuf){
      printk("\nBReadBuf value is 0x%08x\n",BReadBuf);
      }
}

static  int SOC3210_74HC165_button_open(struct inode *inode, struct file *filp){
    int reg;
    printk("Welcome to use 74HC165 driver\n");
    outb(0x3f,SOC3210_LPB_MISC_BASE + REG_LPB_MISC_CTL);
    outb(0x05,SOC3210_LPB_MISC_BASE + REG_LPB_GPIO_OE);
    printk("init 74HC165 is done\n");
    SOC3210_74HC165_READ(reg, SOC3210_74HC165_PL);
    printk("74HC165_PL value is 0x%04X\n",reg);
    SOC3210_74HC165_READ(reg, SOC3210_74HC165_CLK);
    printk("74HC165_CLK value is 0x%04X\n",reg);
    return 0;
}

static  ssize_t SOC3210_74HC165_button_read(struct file  *filp, char __user *buf, size_t count, loff_t *oppos){
    int i;
    button_read();
    if(BReadBuf){
    copy_to_user(buf,&BReadBuf,count);
    BReadBuf = 0;
    return count;
    }
    return count;
}

static int SOC3210_74HC165_button_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg){
    return 0;
}

static  struct file_operations SOC3210_74HC165_button_fops = {
    .open = SOC3210_74HC165_button_open,
    .read = SOC3210_74HC165_button_read,
    .ioctl = SOC3210_74HC165_button_ioctl,
};

static  int __init  SOC3210_74HC165_button_init(void){
    int ret;
    printk("======================button init=========================\n");
    ret = register_chrdev(0,"SOC3210_74HC165_button",&SOC3210_74HC165_button_fops);
    if(ret < 0){
      printk("74HC165_button can't get major number !\n");
      return ret;
    }

#ifdef CONFIG_DEVFS_FS
    devfs_button_dir = devfs_mk_dir(NULL,"SOC3210_74HC165_button",NULL);
    devfs_buttonraw = devfs_register(devfs_kbd_dir,"0raw",DEVFS_FL_DEFAULT,kbdMajor,KBDRAW_MINOR,S_IFCHR|S_IRUSR|S_IWUSR,&SOC3210_74HC165_button_fops,NULL);
#endif
    return 0;
}

static  void  __exit  SOC3210_74HC165_button_exit(void){
}

module_init(SOC3210_74HC165_button_init);
module_exit(SOC3210_74HC165_button_exit);