speakup: extend synth buffer to 16bit unicode characters

This extends the synth buffer slots to 16bit, so as to hold 16bit
unicode characters.

synth_buffer_getc and synth_buffer_peek now return 16bit characters.
Speech synthesizers which do not support characters beyond latin1 can
use the synth_buffer_skip_nonlatin1() helper to skip the non-latin1
characters before getting or peeking. All synthesizers are made to use
it for now.

This makes synth_buffer_add take a 16bit character. For simplicity for
now, synth_printf is left to using latin1 formats and strings.
synth_putwc, synth_putwc_s, synth_putws and synth_putws_s helpers are
however added to put 16bit characters and strings.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Chris Brannon <chris@the-brannons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 24 insertions, 12 deletions

diff --git a/drivers/staging/speakup/buffers.c b/drivers/staging/speakup/buffers.c
index 723d5df44221..f459e4004bfa 100644
--- a/drivers/staging/speakup/buffers.c
+++ b/drivers/staging/speakup/buffers.c
@@ -7,10 +7,10 @@
 
 #define SYNTH_BUF_SIZE 8192	/* currently 8K bytes */
 
-static u_char synth_buffer[SYNTH_BUF_SIZE];	/* guess what this is for! */
-static u_char *buff_in = synth_buffer;
-static u_char *buff_out = synth_buffer;
-static u_char *buffer_end = synth_buffer + SYNTH_BUF_SIZE - 1;
+static u16 synth_buffer[SYNTH_BUF_SIZE];	/* guess what this is for! */
+static u16 *buff_in = synth_buffer;
+static u16 *buff_out = synth_buffer;
+static u16 *buffer_end = synth_buffer + SYNTH_BUF_SIZE - 1;
 
 /* These try to throttle applications by stopping the TTYs
  * Note: we need to make sure that we will restart them eventually, which is
@@ -44,13 +44,13 @@ static void speakup_stop_ttys(void)
 
 static int synth_buffer_free(void)
 {
-	int bytes_free;
+	int chars_free;
 
 	if (buff_in >= buff_out)
-		bytes_free = SYNTH_BUF_SIZE - (buff_in - buff_out);
+		chars_free = SYNTH_BUF_SIZE - (buff_in - buff_out);
 	else
-		bytes_free = buff_out - buff_in;
-	return bytes_free;
+		chars_free = buff_out - buff_in;
+	return chars_free;
 }
 
 int synth_buffer_empty(void)
@@ -59,7 +59,7 @@ int synth_buffer_empty(void)
 }
 EXPORT_SYMBOL_GPL(synth_buffer_empty);
 
-void synth_buffer_add(char ch)
+void synth_buffer_add(u16 ch)
 {
 	if (!synth->alive) {
 		/* This makes sure that we won't stop TTYs if there is no synth
@@ -78,9 +78,9 @@ void synth_buffer_add(char ch)
 		buff_in = synth_buffer;
 }
 
-char synth_buffer_getc(void)
+u16 synth_buffer_getc(void)
 {
-	char ch;
+	u16 ch;
 
 	if (buff_out == buff_in)
 		return 0;
@@ -91,7 +91,7 @@ char synth_buffer_getc(void)
 }
 EXPORT_SYMBOL_GPL(synth_buffer_getc);
 
-char synth_buffer_peek(void)
+u16 synth_buffer_peek(void)
 {
 	if (buff_out == buff_in)
 		return 0;
@@ -99,6 +99,18 @@ char synth_buffer_peek(void)
 }
 EXPORT_SYMBOL_GPL(synth_buffer_peek);
 
+void synth_buffer_skip_nonlatin1(void)
+{
+	while (buff_out != buff_in) {
+		if (*buff_out < 0x100)
+			return;
+		buff_out++;
+		if (buff_out > buffer_end)
+			buff_out = synth_buffer;
+	}
+}
+EXPORT_SYMBOL_GPL(synth_buffer_skip_nonlatin1);
+
 void synth_buffer_clear(void)
 {
 	buff_in = synth_buffer;