Viewing file:  scan_keyb.c (2.89 KB) -rw-r--r--
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/*
* $Id: scan_keyb.c,v 1.2 2000/07/04 06:24:42 yaegashi Exp $
* Copyright (C) 2000 YAEGASHI Takeshi
* Generic scan keyboard driver
*/
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/mm.h>
#include <linux/signal.h>
#include <linux/init.h>
#include <linux/kbd_ll.h>
#include <linux/delay.h>
#include <linux/random.h>
#include <linux/poll.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/kbd_kern.h>
#include <linux/timer.h>
#define SCANHZ (HZ/20)
struct scan_keyboard {
struct scan_keyboard *next;
int (*scan)(unsigned char *buffer);
const unsigned char *table;
unsigned char *s0, *s1;
int length;
};
static int scan_jiffies=0;
static struct scan_keyboard *keyboards=NULL;
struct timer_list scan_timer;
static void check_kbd(const unsigned char *table,
unsigned char *new, unsigned char *old, int length)
{
int need_tasklet_schedule=0;
unsigned int xor, bit;
while(length-->0) {
if((xor=*new^*old)==0) {
table+=8;
}
else {
for(bit=0x01; bit<0x100; bit<<=1) {
if(xor&bit) {
handle_scancode(*table, !(*new&bit));
need_tasklet_schedule=1;
#if 0
printk("0x%x %s\n", *table, (*new&bit)?"released":"pressed");
#endif
}
table++;
}
}
new++; old++;
}
if(need_tasklet_schedule)
tasklet_schedule(&keyboard_tasklet);
}
static void scan_kbd(unsigned long dummy)
{
struct scan_keyboard *kbd;
scan_jiffies++;
for(kbd=keyboards; kbd!=NULL; kbd=kbd->next) {
if(scan_jiffies&1) {
if(!kbd->scan(kbd->s0))
check_kbd(kbd->table,
kbd->s0, kbd->s1, kbd->length);
else
memcpy(kbd->s0, kbd->s1, kbd->length);
}
else {
if(!kbd->scan(kbd->s1))
check_kbd(kbd->table,
kbd->s1, kbd->s0, kbd->length);
else
memcpy(kbd->s1, kbd->s0, kbd->length);
}
}
init_timer(&scan_timer);
scan_timer.expires = jiffies + SCANHZ;
scan_timer.data = 0;
scan_timer.function = scan_kbd;
add_timer(&scan_timer);
}
int register_scan_keyboard(int (*scan)(unsigned char *buffer),
const unsigned char *table,
int length)
{
struct scan_keyboard *kbd;
kbd = kmalloc(sizeof(struct scan_keyboard), GFP_KERNEL);
if (kbd == NULL)
goto error_out;
kbd->scan=scan;
kbd->table=table;
kbd->length=length;
kbd->s0 = kmalloc(length, GFP_KERNEL);
if (kbd->s0 == NULL)
goto error_free_kbd;
kbd->s1 = kmalloc(length, GFP_KERNEL);
if (kbd->s1 == NULL)
goto error_free_s0;
memset(kbd->s0, -1, kbd->length);
memset(kbd->s1, -1, kbd->length);
kbd->next=keyboards;
keyboards=kbd;
return 0;
error_free_s0:
kfree(kbd->s0);
error_free_kbd:
kfree(kbd);
error_out:
return -ENOMEM;
}
void __init scan_kbd_init(void)
{
init_timer(&scan_timer);
scan_timer.expires = jiffies + SCANHZ;
scan_timer.data = 0;
scan_timer.function = scan_kbd;
add_timer(&scan_timer);
printk(KERN_INFO "Generic scan keyboard driver initialized\n");
}
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