diff options
Diffstat (limited to 'kernel/debug/kdb/kdb_keyboard.c')
| -rw-r--r-- | kernel/debug/kdb/kdb_keyboard.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/kernel/debug/kdb/kdb_keyboard.c b/kernel/debug/kdb/kdb_keyboard.c new file mode 100644 index 000000000..f87c750d3 --- /dev/null +++ b/kernel/debug/kdb/kdb_keyboard.c @@ -0,0 +1,262 @@ +/* + * 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> + +/* 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; + } +} |