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/*
* drivers/s390/char/ctrlchar.c
* Unified handling of special chars.
*
* Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
*
*/
#include <linux/config.h>
#include <linux/types.h>
#include <linux/tty.h>
#include <linux/interrupt.h>
#include <linux/sysrq.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#include <asm/cpcmd.h>
#include <asm/irq.h>
#ifdef CONFIG_MAGIC_SYSRQ
static int ctrlchar_sysrq_key;
static struct tq_struct ctrlchar_tq;
static void
ctrlchar_handle_sysrq(struct tty_struct *tty) {
handle_sysrq(ctrlchar_sysrq_key, NULL, NULL, tty);
}
#endif
void ctrlchar_init(void) {
#ifdef CONFIG_MAGIC_SYSRQ
static int init_done = 0;
if (init_done++)
return;
INIT_LIST_HEAD(&ctrlchar_tq.list);
ctrlchar_tq.sync = 0;
ctrlchar_tq.routine = (void (*)(void *)) ctrlchar_handle_sysrq;
#endif
}
/**
* Check for special chars at start of input.
*
* @param buf Console input buffer.
* @param len Length of valid data in buffer.
* @param tty The tty struct for this console.
* @return NULL, if nothing matched, (char *)-1, if buffer contents
* should be ignored, otherwise pointer to char to be inserted.
*/
char *ctrlchar_handle(const char *buf, int len, struct tty_struct *tty) {
static char ret;
if ((len < 2) || (len > 3))
return NULL;
/* hat is 0xb1 in codepage 037 (US etc.) and thus */
/* converted to 0x5e in ascii ('^') */
if ((buf[0] != '^') && (buf[0] != '\252'))
return NULL;
switch (buf[1]) {
#ifdef CONFIG_MAGIC_SYSRQ
case '-':
if (len == 3) {
ctrlchar_sysrq_key = buf[2];
ctrlchar_tq.data = tty;
queue_task(&ctrlchar_tq, &tq_immediate);
mark_bh(IMMEDIATE_BH);
return (char *)-1;
}
break;
#endif
case 'c':
if (len == 2) {
ret = INTR_CHAR(tty);
return &ret;
}
break;
case 'd':
if (len == 2) {
ret = EOF_CHAR(tty);
return &ret;
}
break;
case 'z':
if (len == 2) {
ret = SUSP_CHAR(tty);
return &ret;
}
break;
}
return NULL;
}
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