/*
* Kernel Debugger Architecture Dependent Console I/O handler
*
* This file is subject to the terms and conditions of the GNU General Public
* License.
*
* Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*/
#include <linux/kdb.h>
#include <linux/keyboard.h>
#include <linux/ctype.h>
#include <linux/io.h>
#include "kdb_private.h"
/* Keyboard Controller Registers on normal PCs. */
#define KBD_STATUS_REG 0x64 /* Status register (R) */
#define KBD_DATA_REG 0x60 /* Keyboard data register (R/W) */
/* Status Register Bits */
#define KBD_STAT_OBF 0x01 /* Keyboard output buffer full */
#define KBD_STAT_MOUSE_OBF 0x20 /* Mouse output buffer full */
static int kbd_exists;
static int kbd_last_ret;
/*
* Check if the keyboard controller has a keypress for us.
* Some parts (Enter Release, LED change) are still blocking polled here,
* but hopefully they are all short.
*/
int kdb_get_kbd_char(void)
{
int scancode, scanstatus;
static int shift_lock; /* CAPS LOCK state (0-off, 1-on) */
static int shift_key; /* Shift next keypress */
static int ctrl_key;
u_short keychar;
if (KDB_FLAG(NO_I8042) || KDB_FLAG(NO_VT_CONSOLE) ||
(inb(KBD_STATUS_REG) == 0xff && inb(KBD_DATA_REG) == 0xff)) {
kbd_exists = 0;
return -1;
}
kbd_exists = 1;
if ((inb(KBD_STATUS_REG) & KBD_STAT_OBF) == 0)
return -1;
/*
* Fetch the scancode
*/
scancode = inb(KBD_DATA_REG);
scanstatus = inb(KBD_STATUS_REG);
/*
* Ignore mouse events.
*/
if (scanstatus & KBD_STAT_MOUSE_OBF)
return -1;
/*
* Ignore release, trigger on make
* (except for shift keys, where we want to
* keep the shift state so long as the key is
* held down).
*/
if (((scancode&0x7f) == 0x2a) || ((scancode&0x7f) == 0x36)) {
/*
* Next key may use shift table
*/
if ((scancode & 0x80) == 0)
shift_key = 1;
else
shift_key = 0;
return -1;
}
if ((scancode&0x7f) == 0x1d) {
/*
* Left ctrl key
*/
if ((scancode & 0x80) == 0)
ctrl_key = 1;
else
ctrl_key = 0;
return -1;
}
if ((scancode & 0x80) != 0) {
if (scancode == 0x9c)
kbd_last_ret = 0;
return -1;
}
scancode &= 0x7f;
/*
* Translate scancode
*/
if (scancode == 0x3a) {
/*
* Toggle caps lock
*/
shift_lock ^= 1;
#ifdef KDB_BLINK_LED
kdb_toggleled(0x4);
#endif
return -1;
}
if (scancode == 0x0e) {
/*
* Backspace
*/
return 8;
}
/* Special Key */
switch (scancode) {
case 0xF: /* Tab */
return 9;
case 0x53: /* Del */
return 4;
case 0x47: /* Home */
return 1;
case 0x4F: /* End */
return 5;
case 0x4B: /* Left */
return 2;
case 0x48: /* Up */
return 16;
case 0x50: /* Down */
return 14;
case 0x4D: /* Right */
return 6;
}
if (scancode == 0xe0)
return -1;
/*
* For Japanese 86/106 keyboards
* See comment in drivers/char/pc_keyb.c.
* - Masahiro Adegawa
*/
if (scancode == 0x73)
scancode = 0x59;
else if (scancode == 0x7d)
scancode = 0x7c;
if (!shift_lock && !shift_key && !ctrl_key) {
keychar = plain_map[scancode];
} else if ((shift_lock || shift_key) && key_maps[1]) {
keychar = key_maps[1][scancode];
} else if (ctrl_key && key_maps[4]) {
keychar = key_maps[4][scancode];
} else {
keychar = 0x0020;
kdb_printf("Unknown state/scancode (%d)\n", scancode);
}
keychar &= 0x0fff;
if (keychar == '\t')
keychar = ' ';
switch (KTYP(keychar)) {
case KT_LETTER:
case KT_LATIN:
if (isprint(keychar))
break; /* printable characters */
fallthrough;
case KT_SPEC:
if (keychar == K_ENTER)
break;
fallthrough;
default:
return -1; /* ignore unprintables */
}
if (scancode == 0x1c) {
kbd_last_ret = 1;
return 13;
}
return keychar & 0xff;
}
EXPORT_SYMBOL_GPL(kdb_get_kbd_char);
/*
* Best effort cleanup of ENTER break codes on leaving KDB. Called on
* exiting KDB, when we know we processed an ENTER or KP ENTER scan
* code.
*/
void kdb_kbd_cleanup_state(void)
{
int scancode, scanstatus;
/*
* Nothing to clean up, since either
* ENTER was never pressed, or has already
* gotten cleaned up.
*/
if (!kbd_last_ret)
return;
kbd_last_ret = 0;
/*
* Enter key. Need to absorb the break code here, lest it gets
* leaked out if we exit KDB as the result of processing 'g'.
*
* This has several interesting implications:
* + Need to handle KP ENTER, which has break code 0xe0 0x9c.
* + Need to handle repeat ENTER and repeat KP ENTER. Repeats
* only get a break code at the end of the repeated
* sequence. This means we can't propagate the repeated key
* press, and must swallow it away.
* + Need to handle possible PS/2 mouse input.
* + Need to handle mashed keys.
*/
while (1) {
while ((inb(KBD_STATUS_REG) & KBD_STAT_OBF) == 0)
cpu_relax();
/*
* Fetch the scancode.
*/
scancode = inb(KBD_DATA_REG);
scanstatus = inb(KBD_STATUS_REG);
/*
* Skip mouse input.
*/
if (scanstatus & KBD_STAT_MOUSE_OBF)
continue;
/*
* If we see 0xe0, this is either a break code for KP
* ENTER, or a repeat make for KP ENTER. Either way,
* since the second byte is equivalent to an ENTER,
* skip the 0xe0 and try again.
*
* If we see 0x1c, this must be a repeat ENTER or KP
* ENTER (and we swallowed 0xe0 before). Try again.
*
* We can also see make and break codes for other keys
* mashed before or after pressing ENTER. Thus, if we
* see anything other than 0x9c, we have to try again.
*
* Note, if you held some key as ENTER was depressed,
* that break code would get leaked out.
*/
if (scancode != 0x9c)
continue;
return;
}
}
Codebase Browser
linux