1 | /* |
2 | * Kernel Debugger Architecture Dependent Console I/O handler |
3 | * |
4 | * This file is subject to the terms and conditions of the GNU General Public |
5 | * License. |
6 | * |
7 | * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved. |
8 | * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. |
9 | */ |
10 | |
11 | #include <linux/kdb.h> |
12 | #include <linux/keyboard.h> |
13 | #include <linux/ctype.h> |
14 | #include <linux/io.h> |
15 | |
16 | #include "kdb_private.h" |
17 | |
18 | /* Keyboard Controller Registers on normal PCs. */ |
19 | |
20 | #define KBD_STATUS_REG 0x64 /* Status register (R) */ |
21 | #define KBD_DATA_REG 0x60 /* Keyboard data register (R/W) */ |
22 | |
23 | /* Status Register Bits */ |
24 | |
25 | #define KBD_STAT_OBF 0x01 /* Keyboard output buffer full */ |
26 | #define KBD_STAT_MOUSE_OBF 0x20 /* Mouse output buffer full */ |
27 | |
28 | static int kbd_exists; |
29 | static int kbd_last_ret; |
30 | |
31 | /* |
32 | * Check if the keyboard controller has a keypress for us. |
33 | * Some parts (Enter Release, LED change) are still blocking polled here, |
34 | * but hopefully they are all short. |
35 | */ |
36 | int kdb_get_kbd_char(void) |
37 | { |
38 | int scancode, scanstatus; |
39 | static int shift_lock; /* CAPS LOCK state (0-off, 1-on) */ |
40 | static int shift_key; /* Shift next keypress */ |
41 | static int ctrl_key; |
42 | u_short keychar; |
43 | |
44 | if (KDB_FLAG(NO_I8042) || KDB_FLAG(NO_VT_CONSOLE) || |
45 | (inb(KBD_STATUS_REG) == 0xff && inb(KBD_DATA_REG) == 0xff)) { |
46 | kbd_exists = 0; |
47 | return -1; |
48 | } |
49 | kbd_exists = 1; |
50 | |
51 | if ((inb(KBD_STATUS_REG) & KBD_STAT_OBF) == 0) |
52 | return -1; |
53 | |
54 | /* |
55 | * Fetch the scancode |
56 | */ |
57 | scancode = inb(KBD_DATA_REG); |
58 | scanstatus = inb(KBD_STATUS_REG); |
59 | |
60 | /* |
61 | * Ignore mouse events. |
62 | */ |
63 | if (scanstatus & KBD_STAT_MOUSE_OBF) |
64 | return -1; |
65 | |
66 | /* |
67 | * Ignore release, trigger on make |
68 | * (except for shift keys, where we want to |
69 | * keep the shift state so long as the key is |
70 | * held down). |
71 | */ |
72 | |
73 | if (((scancode&0x7f) == 0x2a) || ((scancode&0x7f) == 0x36)) { |
74 | /* |
75 | * Next key may use shift table |
76 | */ |
77 | if ((scancode & 0x80) == 0) |
78 | shift_key = 1; |
79 | else |
80 | shift_key = 0; |
81 | return -1; |
82 | } |
83 | |
84 | if ((scancode&0x7f) == 0x1d) { |
85 | /* |
86 | * Left ctrl key |
87 | */ |
88 | if ((scancode & 0x80) == 0) |
89 | ctrl_key = 1; |
90 | else |
91 | ctrl_key = 0; |
92 | return -1; |
93 | } |
94 | |
95 | if ((scancode & 0x80) != 0) { |
96 | if (scancode == 0x9c) |
97 | kbd_last_ret = 0; |
98 | return -1; |
99 | } |
100 | |
101 | scancode &= 0x7f; |
102 | |
103 | /* |
104 | * Translate scancode |
105 | */ |
106 | |
107 | if (scancode == 0x3a) { |
108 | /* |
109 | * Toggle caps lock |
110 | */ |
111 | shift_lock ^= 1; |
112 | |
113 | #ifdef KDB_BLINK_LED |
114 | kdb_toggleled(0x4); |
115 | #endif |
116 | return -1; |
117 | } |
118 | |
119 | if (scancode == 0x0e) { |
120 | /* |
121 | * Backspace |
122 | */ |
123 | return 8; |
124 | } |
125 | |
126 | /* Special Key */ |
127 | switch (scancode) { |
128 | case 0xF: /* Tab */ |
129 | return 9; |
130 | case 0x53: /* Del */ |
131 | return 4; |
132 | case 0x47: /* Home */ |
133 | return 1; |
134 | case 0x4F: /* End */ |
135 | return 5; |
136 | case 0x4B: /* Left */ |
137 | return 2; |
138 | case 0x48: /* Up */ |
139 | return 16; |
140 | case 0x50: /* Down */ |
141 | return 14; |
142 | case 0x4D: /* Right */ |
143 | return 6; |
144 | } |
145 | |
146 | if (scancode == 0xe0) |
147 | return -1; |
148 | |
149 | /* |
150 | * For Japanese 86/106 keyboards |
151 | * See comment in drivers/char/pc_keyb.c. |
152 | * - Masahiro Adegawa |
153 | */ |
154 | if (scancode == 0x73) |
155 | scancode = 0x59; |
156 | else if (scancode == 0x7d) |
157 | scancode = 0x7c; |
158 | |
159 | if (!shift_lock && !shift_key && !ctrl_key) { |
160 | keychar = plain_map[scancode]; |
161 | } else if ((shift_lock || shift_key) && key_maps[1]) { |
162 | keychar = key_maps[1][scancode]; |
163 | } else if (ctrl_key && key_maps[4]) { |
164 | keychar = key_maps[4][scancode]; |
165 | } else { |
166 | keychar = 0x0020; |
167 | kdb_printf("Unknown state/scancode (%d)\n" , scancode); |
168 | } |
169 | keychar &= 0x0fff; |
170 | if (keychar == '\t') |
171 | keychar = ' '; |
172 | switch (KTYP(keychar)) { |
173 | case KT_LETTER: |
174 | case KT_LATIN: |
175 | if (isprint(keychar)) |
176 | break; /* printable characters */ |
177 | fallthrough; |
178 | case KT_SPEC: |
179 | if (keychar == K_ENTER) |
180 | break; |
181 | fallthrough; |
182 | default: |
183 | return -1; /* ignore unprintables */ |
184 | } |
185 | |
186 | if (scancode == 0x1c) { |
187 | kbd_last_ret = 1; |
188 | return 13; |
189 | } |
190 | |
191 | return keychar & 0xff; |
192 | } |
193 | EXPORT_SYMBOL_GPL(kdb_get_kbd_char); |
194 | |
195 | /* |
196 | * Best effort cleanup of ENTER break codes on leaving KDB. Called on |
197 | * exiting KDB, when we know we processed an ENTER or KP ENTER scan |
198 | * code. |
199 | */ |
200 | void kdb_kbd_cleanup_state(void) |
201 | { |
202 | int scancode, scanstatus; |
203 | |
204 | /* |
205 | * Nothing to clean up, since either |
206 | * ENTER was never pressed, or has already |
207 | * gotten cleaned up. |
208 | */ |
209 | if (!kbd_last_ret) |
210 | return; |
211 | |
212 | kbd_last_ret = 0; |
213 | /* |
214 | * Enter key. Need to absorb the break code here, lest it gets |
215 | * leaked out if we exit KDB as the result of processing 'g'. |
216 | * |
217 | * This has several interesting implications: |
218 | * + Need to handle KP ENTER, which has break code 0xe0 0x9c. |
219 | * + Need to handle repeat ENTER and repeat KP ENTER. Repeats |
220 | * only get a break code at the end of the repeated |
221 | * sequence. This means we can't propagate the repeated key |
222 | * press, and must swallow it away. |
223 | * + Need to handle possible PS/2 mouse input. |
224 | * + Need to handle mashed keys. |
225 | */ |
226 | |
227 | while (1) { |
228 | while ((inb(KBD_STATUS_REG) & KBD_STAT_OBF) == 0) |
229 | cpu_relax(); |
230 | |
231 | /* |
232 | * Fetch the scancode. |
233 | */ |
234 | scancode = inb(KBD_DATA_REG); |
235 | scanstatus = inb(KBD_STATUS_REG); |
236 | |
237 | /* |
238 | * Skip mouse input. |
239 | */ |
240 | if (scanstatus & KBD_STAT_MOUSE_OBF) |
241 | continue; |
242 | |
243 | /* |
244 | * If we see 0xe0, this is either a break code for KP |
245 | * ENTER, or a repeat make for KP ENTER. Either way, |
246 | * since the second byte is equivalent to an ENTER, |
247 | * skip the 0xe0 and try again. |
248 | * |
249 | * If we see 0x1c, this must be a repeat ENTER or KP |
250 | * ENTER (and we swallowed 0xe0 before). Try again. |
251 | * |
252 | * We can also see make and break codes for other keys |
253 | * mashed before or after pressing ENTER. Thus, if we |
254 | * see anything other than 0x9c, we have to try again. |
255 | * |
256 | * Note, if you held some key as ENTER was depressed, |
257 | * that break code would get leaked out. |
258 | */ |
259 | if (scancode != 0x9c) |
260 | continue; |
261 | |
262 | return; |
263 | } |
264 | } |
265 | |