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