Input: add support for Braille devices

- Add KEY_BRL_* input keys and K_BRL_* keycodes;
- Add emulation of how braille keyboards usually combine braille dots
  to the console keyboard driver;
- Add handling of unicode U+28xy diacritics.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

include/linux/input.h

@@ -512,6 +512,15 @@ struct input_absinfo {
 #define KEY_FN_S		0x1e3
 #define KEY_FN_B		0x1e4
 
+#define KEY_BRL_DOT1		0x1f1
+#define KEY_BRL_DOT2		0x1f2
+#define KEY_BRL_DOT3		0x1f3
+#define KEY_BRL_DOT4		0x1f4
+#define KEY_BRL_DOT5		0x1f5
+#define KEY_BRL_DOT6		0x1f6
+#define KEY_BRL_DOT7		0x1f7
+#define KEY_BRL_DOT8		0x1f8
+
 /* We avoid low common keys in module aliases so they don't get huge. */
 #define KEY_MIN_INTERESTING	KEY_MUTE
 #define KEY_MAX			0x1ff

include/linux/kbd_kern.h

@@ -135,6 +135,8 @@ static inline void chg_vc_kbd_led(struct kbd_struct * kbd, int flag)
 
 #define U(x) ((x) ^ 0xf000)
 
+#define BRL_UC_ROW 0x2800
+
 /* keyboard.c */
 
 struct console;

include/linux/keyboard.h

@@ -44,6 +44,7 @@ extern unsigned short plain_map[NR_KEYS];
 #define KT_ASCII	9
 #define KT_LOCK		10
 #define KT_SLOCK	12
+#define KT_BRL		14
 
 #define K(t,v)		(((t)<<8)|(v))
 #define KTYP(x)		((x) >> 8)
@@ -427,5 +428,17 @@ extern unsigned short plain_map[NR_KEYS];
 
 #define NR_LOCK		8
 
+#define K_BRL_BLANK     K(KT_BRL, 0)
+#define K_BRL_DOT1      K(KT_BRL, 1)
+#define K_BRL_DOT2      K(KT_BRL, 2)
+#define K_BRL_DOT3      K(KT_BRL, 3)
+#define K_BRL_DOT4      K(KT_BRL, 4)
+#define K_BRL_DOT5      K(KT_BRL, 5)
+#define K_BRL_DOT6      K(KT_BRL, 6)
+#define K_BRL_DOT7      K(KT_BRL, 7)
+#define K_BRL_DOT8      K(KT_BRL, 8)
+
+#define NR_BRL		9
+
 #define MAX_DIACR	256
 #endif