/*
  XT keyboard reader for embedded systems.
  Copyright (C) 2009  Tamas Kemenczy

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifdef __cplusplus
extern "C" {
#endif


// An XT keyboard event.  The phase represents either a XT_KEY_PRESS or
// a XT_KEY_RELEASE.  The symbol is one those defined later in this
// header file.  The modifiers is a bitmask of zero or more XT_MOD_*
// symbols, i.e. XT_MOD_SHIFT | XT_MOD_CTRL.

typedef struct {
  unsigned int phase;
  unsigned int symbol;
  unsigned int modifiers;
} xt_event_t;


// Context for one XT keyboard.  Acts as a software 9-bit shift
// register (shift and scancode), updated with the xt_read
// function.  When a scancode is ready, the ready member is set.  Also
// stores some key state information (modifiers,
// escape).

typedef struct {
  unsigned int ready;
  unsigned int shift;
  unsigned int scancode;
  unsigned int modifiers;
  unsigned int escape;
  xt_event_t *event;
} xt_ctx_t;


// Initialize an XT context.
xt_ctx_t *xt_init_ctx(void);

// Push a bit of data into the context's shift register.
int xt_read(xt_ctx_t *ctx, int bit);

// Handle a pending scancode in the context's shift register.
int xt_handle(xt_ctx_t *ctx, void (*fn)(xt_event_t*));


#define XT_KEY_PRESS 1
#define XT_KEY_RELEASE 0
#define XT_MOD_SHIFT 1
#define XT_MOD_CTRL 2
#define XT_MOD_ALT 4
#define XT_MOD_CAPSLOCK 16
#define XT_MOD_NUMLOCK 32
#define XT_MOD_SUPER 64
#define XT_MOD_SCROLLLOCK 128
#define XT_0 0x0b
#define XT_1 0x02
#define XT_2 0x03
#define XT_3 0x04
#define XT_4 0x05
#define XT_5 0x06
#define XT_6 0x07
#define XT_7 0x08
#define XT_8 0x09
#define XT_9 0x0a
#define XT_A 0x1e
#define XT_B 0x30
#define XT_C 0x2e
#define XT_D 0x20
#define XT_E 0x12
#define XT_F 0x21
#define XT_G 0x22
#define XT_H 0x23
#define XT_I 0x17
#define XT_J 0x24
#define XT_K 0x25
#define XT_L 0x26
#define XT_M 0x32
#define XT_N 0x31
#define XT_O 0x18
#define XT_P 0x19
#define XT_Q 0x10
#define XT_R 0x13
#define XT_S 0x1f
#define XT_T 0x14
#define XT_U 0x16
#define XT_V 0x2f
#define XT_W 0x11
#define XT_X 0x2d
#define XT_Y 0x15
#define XT_Z 0x2c
#define XT_F1 0x3b
#define XT_F2 0x3c
#define XT_F3 0x3d
#define XT_F4 0x3e
#define XT_F5 0x3f
#define XT_F6 0x40
#define XT_F7 0x41
#define XT_F8 0x42
#define XT_F9 0x43
#define XT_F10 0x44
#define XT_F11 0x57
#define XT_F12 0x58
#define XT_ESCAPE 0x01
#define XT_GRAVE 0x29
#define XT_QUOTELEFT 0x29
#define XT_BRACKETLEFT 0x1a
#define XT_BRACKETRIGHT 0x1b
#define XT_BACKSLASH 0x2b
#define XT_SEMICOLON 0x27
#define XT_APOSTROPHE 0x28
#define XT_COMMA 0x33
#define XT_PERIOD 0x34
#define XT_SLASH 0x35
#define XT_MINUS 0x0c
#define XT_EQUAL 0x0d
#define XT_TAB 0x0f
#define XT_ENTER 0x1c
#define XT_RETURN 0x1c
#define XT_BACKSPACE 0x0e
#define XT_CAPSLOCK 0x3a
#define XT_LSHIFT 0x2a
#define XT_RSHIT 0x36
#define XT_LCTRL 0x1d
#define XT_RCTRL 0xe01d
#define XT_LALT 0x38
#define XT_RALT 0xe038
#define XT_SPACE 0x39
#define XT_PRINT 0xe02ae037
#define XT_SYSREQ 0xe02ae037
#define XT_SCROLLLOCK 0x46
#define XT_BREAK 0xe11d45e19dc5
#define XT_PAUSE 0xe11d45e19dc5
#define XT_INSERT 0xe052
#define XT_DELETE 0xe053
#define XT_HOME 0xe047
#define XT_END 0xe04f
#define XT_PAGEUP 0xe049
#define XT_PAGEDOWN 0xe051
#define XT_UP 0xe048
#define XT_LEFT 0xe04b
#define XT_RIGHT 0xe04d
#define XT_DOWN 0xe050
#define XT_NUMLOCK 0x45
#define XT_NUM_DIVIDE 0xe035
#define XT_NUM_MULTIPY 0x57
#define XT_NUM_SUBTRACT 0x4a
#define XT_NUM_ADD 0x4e
#define XT_NUM_ENTER 0xeo1c
#define XT_NUM_INSERT 0x52
#define XT_NUM_DELETE 0x53
#define XT_NUM_UP 0x48
#define XT_NUM_LEFT 0x4b
#define XT_NUM_RIGHT 0x4d
#define XT_NUM_DOWN 0x50
#define XT_NUM_HOME 0x47
#define XT_NUM_END 0x4f
#define XT_NUM_PAGEUP 0x49
#define XT_NUM_PAGEDOWN 0x51
/* #define XT_ASCIITILDE (0x29 | 1U << 8) */
/* #define XT_EXCLAMATION (0x02 | 1U << 8) */
/* #define XT_AT (0x03 | 1U << 8) */
/* #define XT_HASH (0x04 | 1U << 8) */
/* #define XT_POUND (0x04 | 1U << 8) */
/* #define XT_DOLLAR (0x05 | 1U << 8) */
/* #define XT_PERCENT (0x06 | 1U << 8) */
/* #define XT_ASCIICIRCUM (0x07 | 1U << 8) */
/* #define XT_AMPERSAND (0x08 | 1U << 8) */
/* #define XT_ASTERISK (0x09 | 1U << 8) */
/* #define XT_PARENLEFT (0x0a | 1U << 8) */
/* #define XT_PARENRIGHT (0x1e | 1U << 8) */
/* #define XT_UNDERSCORE (0x0c | 1U << 8) */
/* #define XT_PLUS (0x0d | 1U << 8) */
/* #define XT_BRACELEFT (0x1a | 1U << 8) */
/* #define XT_BRACERIGHT (0x1b | 1U << 8) */
/* #define XT_BAR (0x2b | 1U << 8) */
/* #define XT_COLON (0x27 | 1U << 8) */
/* #define XT_LESS (0x33 | 1U << 8) */
/* #define XT_GREATER (0x34 | 1U << 8) */
/* #define XT_QUESTION (0x35 | 1U << 8) */
/* #define XT_DOUBLEQUOTE (0x28 | 1U << 8) */
/* #define XT_NUM_0 (0x52 | 1U << 9) */
/* #define XT_NUM_1 (0x4f | 1U << 9) */
/* #define XT_NUM_2 (0x50 | 1U << 9) */
/* #define XT_NUM_3 (0x51 | 1U << 9) */
/* #define XT_NUM_4 (0x4b | 1U << 9) */
/* #define XT_NUM_5 (0x4c | 1U << 9) */
/* #define XT_NUM_6 (0x4d | 1U << 9) */
/* #define XT_NUM_7 (0x47 | 1U << 9) */
/* #define XT_NUM_8 (0x48 | 1U << 9) */
/* #define XT_NUM_9 (0x49 | 1U << 9) */
/* #define XT_NUM_DECIMAL (0x53 | 1U << 9) */


#ifdef __cplusplus
}
#endif