summaryrefslogtreecommitdiffstats
path: root/kernel/debug/kdb/kdb_keyboard.c
blob: 4bca634975c0ed008de18d415e348a4cbab966af (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/*
 * 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/module.h>
#include <linux/io.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;

/*
 * 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)
		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 */
		/* drop through */
	case KT_SPEC:
		if (keychar == K_ENTER)
			break;
		/* drop through */
	default:
		return -1;	/* ignore unprintables */
	}

	if ((scancode & 0x7f) == 0x1c) {
		/*
		 * enter key.  All done.  Absorb the release scancode.
		 */
		while ((inb(KBD_STATUS_REG) & KBD_STAT_OBF) == 0)
			;

		/*
		 * Fetch the scancode
		 */
		scancode = inb(KBD_DATA_REG);
		scanstatus = inb(KBD_STATUS_REG);

		while (scanstatus & KBD_STAT_MOUSE_OBF) {
			scancode = inb(KBD_DATA_REG);
			scanstatus = inb(KBD_STATUS_REG);
		}

		if (scancode != 0x9c) {
			/*
			 * Wasn't an enter-release,  why not?
			 */
			kdb_printf("kdb: expected enter got 0x%x status 0x%x\n",
			       scancode, scanstatus);
		}

		return 13;
	}

	return keychar & 0xff;
}
EXPORT_SYMBOL_GPL(kdb_get_kbd_char);