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>

4 files changed, 125 insertions, 17 deletions

diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index 8b603b2d1c42..935670a3cd98 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -74,7 +74,7 @@ void compute_shiftstate(void);
         k_self,         k_fn,           k_spec,         k_pad,\
         k_dead,         k_cons,         k_cur,          k_shift,\
         k_meta,         k_ascii,        k_lock,         k_lowercase,\
-        k_slock,        k_dead2,        k_ignore,       k_ignore
+        k_slock,        k_dead2,        k_brl,          k_ignore
 
 typedef void (k_handler_fn)(struct vc_data *vc, unsigned char value,
                             char up_flag, struct pt_regs *regs);
@@ -100,7 +100,7 @@ static fn_handler_fn *fn_handler[] = { FN_HANDLERS };
 const int max_vals[] = {
         255, ARRAY_SIZE(func_table) - 1, ARRAY_SIZE(fn_handler) - 1, NR_PAD - 1,
         NR_DEAD - 1, 255, 3, NR_SHIFT - 1, 255, NR_ASCII - 1, NR_LOCK - 1,
-        255, NR_LOCK - 1, 255
+        255, NR_LOCK - 1, 255, NR_BRL - 1
 };
 
 const int NR_TYPES = ARRAY_SIZE(max_vals);
@@ -126,7 +126,7 @@ static unsigned long key_down[NBITS(KEY_MAX)];		/* keyboard key bitmap */
 static unsigned char shift_down[NR_SHIFT];              /* shift state counters.. */
 static int dead_key_next;
 static int npadch = -1;                                 /* -1 or number assembled on pad */
-static unsigned char diacr;
+static unsigned int diacr;
 static char rep;                                        /* flag telling character repeat */
 
 static unsigned char ledstate = 0xff;                   /* undefined */
@@ -394,22 +394,30 @@ void compute_shiftstate(void)
  * Otherwise, conclude that DIACR was not combining after all,
  * queue it and return CH.
  */
-static unsigned char handle_diacr(struct vc_data *vc, unsigned char ch)
+static unsigned int handle_diacr(struct vc_data *vc, unsigned int ch)
 {
-        int d = diacr;
+        unsigned int d = diacr;
         unsigned int i;
 
         diacr = 0;
 
-        for (i = 0; i < accent_table_size; i++) {
-                if (accent_table[i].diacr == d && accent_table[i].base == ch)
-                        return accent_table[i].result;
+        if ((d & ~0xff) == BRL_UC_ROW) {
+                if ((ch & ~0xff) == BRL_UC_ROW)
+                        return d | ch;
+        } else {
+                for (i = 0; i < accent_table_size; i++)
+                        if (accent_table[i].diacr == d && accent_table[i].base == ch)
+                                return accent_table[i].result;
         }
 
-        if (ch == ' ' || ch == d)
+        if (ch == ' ' || ch == (BRL_UC_ROW|0) || ch == d)
                 return d;
 
-        put_queue(vc, d);
+        if (kbd->kbdmode == VC_UNICODE)
+                to_utf8(vc, d);
+        else if (d < 0x100)
+                put_queue(vc, d);
+
         return ch;
 }
 
@@ -419,7 +427,10 @@ static unsigned char handle_diacr(struct vc_data *vc, unsigned char ch)
 static void fn_enter(struct vc_data *vc, struct pt_regs *regs)
 {
         if (diacr) {
-                put_queue(vc, diacr);
+                if (kbd->kbdmode == VC_UNICODE)
+                        to_utf8(vc, diacr);
+                else if (diacr < 0x100)
+                        put_queue(vc, diacr);
                 diacr = 0;
         }
         put_queue(vc, 13);
@@ -615,7 +626,7 @@ static void k_lowercase(struct vc_data *vc, unsigned char value, char up_flag, s
         printk(KERN_ERR "keyboard.c: k_lowercase was called - impossible\n");
 }
 
-static void k_self(struct vc_data *vc, unsigned char value, char up_flag, struct pt_regs *regs)
+static void k_unicode(struct vc_data *vc, unsigned int value, char up_flag, struct pt_regs *regs)
 {
         if (up_flag)
                 return;         /* no action, if this is a key release */
@@ -628,7 +639,10 @@ static void k_self(struct vc_data *vc, unsigned char value, char up_flag, struct
                 diacr = value;
                 return;
         }
-        put_queue(vc, value);
+        if (kbd->kbdmode == VC_UNICODE)
+                to_utf8(vc, value);
+        else if (value < 0x100)
+                put_queue(vc, value);
 }
 
 /*
@@ -636,13 +650,23 @@ static void k_self(struct vc_data *vc, unsigned char value, char up_flag, struct
  * dead keys modifying the same character. Very useful
  * for Vietnamese.
  */
-static void k_dead2(struct vc_data *vc, unsigned char value, char up_flag, struct pt_regs *regs)
+static void k_deadunicode(struct vc_data *vc, unsigned int value, char up_flag, struct pt_regs *regs)
 {
         if (up_flag)
                 return;
         diacr = (diacr ? handle_diacr(vc, value) : value);
 }
 
+static void k_self(struct vc_data *vc, unsigned char value, char up_flag, struct pt_regs *regs)
+{
+        k_unicode(vc, value, up_flag, regs);
+}
+
+static void k_dead2(struct vc_data *vc, unsigned char value, char up_flag, struct pt_regs *regs)
+{
+        k_deadunicode(vc, value, up_flag, regs);
+}
+
 /*
  * Obsolete - for backwards compatibility only
  */
@@ -650,7 +674,7 @@ static void k_dead(struct vc_data *vc, unsigned char value, char up_flag, struct
 {
         static unsigned char ret_diacr[NR_DEAD] = {'`', '\'', '^', '~', '"', ',' };
         value = ret_diacr[value];
-        k_dead2(vc, value, up_flag, regs);
+        k_deadunicode(vc, value, up_flag, regs);
 }
 
 static void k_cons(struct vc_data *vc, unsigned char value, char up_flag, struct pt_regs *regs)
@@ -835,6 +859,62 @@ static void k_slock(struct vc_data *vc, unsigned char value, char up_flag, struc
         }
 }
 
+/* by default, 300ms interval for combination release */
+static long brl_timeout = 300;
+MODULE_PARM_DESC(brl_timeout, "Braille keys release delay in ms (0 for combination on first release, < 0 for dead characters)");
+module_param(brl_timeout, long, 0644);
+static void k_brl(struct vc_data *vc, unsigned char value, char up_flag, struct pt_regs *regs)
+{
+        static unsigned pressed,committing;
+        static unsigned long releasestart;
+
+        if (kbd->kbdmode != VC_UNICODE) {
+                if (!up_flag)
+                        printk("keyboard mode must be unicode for braille patterns\n");
+                return;
+        }
+
+        if (!value) {
+                k_unicode(vc, BRL_UC_ROW, up_flag, regs);
+                return;
+        }
+
+        if (value > 8)
+                return;
+
+        if (brl_timeout < 0) {
+                k_deadunicode(vc, BRL_UC_ROW | (1 << (value - 1)), up_flag, regs);
+                return;
+        }
+
+        if (up_flag) {
+                if (brl_timeout) {
+                        if (!committing ||
+                            jiffies - releasestart > (brl_timeout * HZ) / 1000) {
+                                committing = pressed;
+                                releasestart = jiffies;
+                        }
+                        pressed &= ~(1 << (value - 1));
+                        if (!pressed) {
+                                if (committing) {
+                                        k_unicode(vc, BRL_UC_ROW | committing, 0, regs);
+                                        committing = 0;
+                                }
+                        }
+                } else {
+                        if (committing) {
+                                k_unicode(vc, BRL_UC_ROW | committing, 0, regs);
+                                committing = 0;
+                        }
+                        pressed &= ~(1 << (value - 1));
+                }
+        } else {
+                pressed |= 1 << (value - 1);
+                if (!brl_timeout)
+                        committing = pressed;
+        }
+}
+
 /*
  * The leds display either (i) the status of NumLock, CapsLock, ScrollLock,
  * or (ii) whatever pattern of lights people want to show using KDSETLED,
@@ -1125,9 +1205,13 @@ static void kbd_keycode(unsigned int keycode, int down,
         }
 
         if (keycode > NR_KEYS)
-                return;
+                if (keycode >= KEY_BRL_DOT1 && keycode <= KEY_BRL_DOT8)
+                        keysym = K(KT_BRL, keycode - KEY_BRL_DOT1 + 1);
+                else
+                        return;
+        else
+                keysym = key_map[keycode];
 
-        keysym = key_map[keycode];
         type = KTYP(keysym);
 
         if (type < 0xf0) {
diff --git a/include/linux/input.h b/include/linux/input.h
index 393da04f4301..b0e612dda0cf 100644
--- a/include/linux/input.h
+++ b/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
diff --git a/include/linux/kbd_kern.h b/include/linux/kbd_kern.h
index e87c32a5c86a..4eb851ece080 100644
--- a/include/linux/kbd_kern.h
+++ b/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;
diff --git a/include/linux/keyboard.h b/include/linux/keyboard.h
index 08488042d74a..de76843bbe8a 100644
--- a/include/linux/keyboard.h
+++ b/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