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path: root/drivers/char/scan_keyb.c
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Diffstat (limited to 'drivers/char/scan_keyb.c')
-rw-r--r--drivers/char/scan_keyb.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/char/scan_keyb.c b/drivers/char/scan_keyb.c
new file mode 100644
index 00000000000..2b5bb4f5754
--- /dev/null
+++ b/drivers/char/scan_keyb.c
@@ -0,0 +1,149 @@
+/*
+ * $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");
+}