input: Add ANSI 3.64 escape sequence generation.

To support Non-ASCII keys (ex, Fn, PgUp/Dn, arrow keys, ...), we need to translate key code into escape sequence. (Updated by sjg@chromium.org to move away from a function to store keycodes, so we can easily record how many were sent. We now need to return this from input_send_keycodes() so we know whether keys were generated.) Signed-off-by: Hung-Te Lin <hungte@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Tom Rini <trini@ti.com>

input: Add ANSI 3.64 escape sequence generation.
To support Non-ASCII keys (ex, Fn, PgUp/Dn, arrow keys, ...), we need to translate key code into escape sequence. (Updated by sjg@chromium.org to move away from a function to store keycodes, so we can easily record how many were sent. We now need to return this from input_send_keycodes() so we know whether keys were generated.) Signed-off-by: Hung-Te Lin <hungte@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Tom Rini <trini@ti.com>
Hung-Te Lin · Tom Rini
1 parent 59a1b72ced
Showing 2 changed files with 89 additions and 15 deletions Side-by-side Diff
drivers/input/input.c
include/input.h
@@ -93,7 +93,23 @@
 	'\r', 0xff, 0xff
 };
  
+/*
+ * Scan key code to ANSI 3.64 escape sequence table.  This table is
+ * incomplete in that it does not include all possible extra keys.
+ */
+static struct {
+	int kbd_scan_code;
+	char *escape;
+} kbd_to_ansi364[] = {
+	{ KEY_UP, "\033[A"},
+	{ KEY_DOWN, "\033[B"},
+	{ KEY_RIGHT, "\033[C"},
+	{ KEY_LEFT, "\033[D"},
+};
  
+/* Maximum number of output characters that an ANSI sequence expands to */
+#define ANSI_CHAR_MAX	3
+
 int input_queue_ascii(struct input_config *config, int ch)
 {
 	if (config->fifo_in + 1 == INPUT_BUFFER_LEN) {
  
  
  
  
  
  
@@ -289,24 +305,67 @@
 }
  
 /**
+ * Checks and converts a special key code into ANSI 3.64 escape sequence.
+ *
+ * @param config	Input state
+ * @param keycode	Key code to examine
+ * @param output_ch	Buffer to place output characters into. It should
+ *			be at least ANSI_CHAR_MAX bytes long, to allow for
+ *			an ANSI sequence.
+ * @param max_chars	Maximum number of characters to add to output_ch
+ * @return number of characters output, if the key was converted, otherwise 0.
+ *	This may be larger than max_chars, in which case the overflow
+ *	characters are not output.
+ */
+static int input_keycode_to_ansi364(struct input_config *config,
+		int keycode, char output_ch[], int max_chars)
+{
+	const char *escape;
+	int ch_count;
+	int i;
+
+	for (i = ch_count = 0; i < ARRAY_SIZE(kbd_to_ansi364); i++) {
+		if (keycode != kbd_to_ansi364[i].kbd_scan_code)
+			continue;
+		for (escape = kbd_to_ansi364[i].escape; *escape; escape++) {
+			if (ch_count < max_chars)
+				output_ch[ch_count] = *escape;
+			ch_count++;
+		}
+		return ch_count;
+	}
+
+	return 0;
+}
+
+/**
+ * Converts and queues a list of key codes in escaped ASCII string form
  * Convert a list of key codes into ASCII
  *
  * You must call input_check_keycodes() before this. It turns the keycode
- * list into a list of ASCII characters which are ready to send to the
- * input layer.
+ * list into a list of ASCII characters and sends them to the input layer.
  *
  * Characters which were seen last time do not generate fresh ASCII output.
+ * The output (calls to queue_ascii) may be longer than num_keycodes, if the
+ * keycode contains special keys that was encoded to longer escaped sequence.
  *
  * @param config	Input state
  * @param keycode	List of key codes to examine
  * @param num_keycodes	Number of key codes
+ * @param output_ch	Buffer to place output characters into. It should
+ *			be at last ANSI_CHAR_MAX * num_keycodes, to allow for
+ *			ANSI sequences.
+ * @param max_chars	Maximum number of characters to add to output_ch
  * @param same		Number of key codes which are the same
+ * @return number of characters written into output_ch, or -1 if we would
+ *	exceed max_chars chars.
  */
 static int input_keycodes_to_ascii(struct input_config *config,
-		int keycode[], int num_keycodes, char output_ch[], int same)
+		int keycode[], int num_keycodes, char output_ch[],
+		int max_chars, int same)
 {
 	struct input_key_xlate *table;
-	int ch_count;
+	int ch_count = 0;
 	int i;
  
 	table = &config->table[0];
  
  
  
@@ -321,19 +380,31 @@
 		}
 	}
  
-	/* now find normal keys */
-	for (i = ch_count = 0; i < num_keycodes; i++) {
+	/* Start conversion by looking for the first new keycode (by same). */
+	for (i = same; i < num_keycodes; i++) {
 		int key = keycode[i];
+		int ch = (key < table->num_entries) ? table->xlate[key] : 0xff;
  
-		if (key < table->num_entries && i >= same) {
-			int ch = table->xlate[key];
-
-			/* If a normal key with an ASCII value, add it! */
-			if (ch != 0xff)
-				output_ch[ch_count++] = (uchar)ch;
+		/*
+		 * For a normal key (with an ASCII value), add it; otherwise
+		 * translate special key to escape sequence if possible.
+		 */
+		if (ch != 0xff) {
+			if (ch_count < max_chars)
+				output_ch[ch_count] = (uchar)ch;
+			ch_count++;
+		} else {
+			ch_count += input_keycode_to_ansi364(config, key,
+						output_ch, max_chars);
 		}
 	}
  
+	if (ch_count > max_chars) {
+		debug("%s: Output char buffer overflow size=%d, need=%d\n",
+		      __func__, max_chars, ch_count);
+		return -1;
+	}
+
 	/* ok, so return keys */
 	return ch_count;
 }
@@ -341,7 +412,7 @@
 int input_send_keycodes(struct input_config *config,
 			int keycode[], int num_keycodes)
 {
-	char ch[num_keycodes];
+	char ch[num_keycodes * ANSI_CHAR_MAX];
 	int count, i, same = 0;
 	int is_repeat = 0;
 	unsigned delay_ms;
@@ -363,7 +434,7 @@
 	}
  
 	count = input_keycodes_to_ascii(config, keycode, num_keycodes,
-					ch, is_repeat ? 0 : same);
+					ch, sizeof(ch), is_repeat ? 0 : same);
 	for (i = 0; i < count; i++)
 		input_queue_ascii(config, ch[i]);
 	delay_ms = is_repeat ?
@@ -371,7 +442,8 @@
 			config->repeat_delay_ms;
  
 	config->next_repeat_ms = get_timer(0) + delay_ms;
-	return 0;
+
+	return count;
 }
  
 int input_add_table(struct input_config *config, int left_keycode,
@@ -84,6 +84,8 @@
  * @param config	Input state
  * @param keycode	List of key codes to examine
  * @param num_keycodes	Number of key codes
+ * @return number of ascii characters sent, or 0 if none, or -1 for an
+ *	internal error
  */
 int input_send_keycodes(struct input_config *config, int keycode[], int count);
...	...	@@ -93,7 +93,23 @@
93	93	'\r', 0xff, 0xff
94	94	};
95	95
	96	+/*
	97	+ * Scan key code to ANSI 3.64 escape sequence table. This table is
	98	+ * incomplete in that it does not include all possible extra keys.
	99	+ */
	100	+static struct {
	101	+ int kbd_scan_code;
	102	+ char *escape;
	103	+} kbd_to_ansi364[] = {
	104	+ { KEY_UP, "\033[A"},
	105	+ { KEY_DOWN, "\033[B"},
	106	+ { KEY_RIGHT, "\033[C"},
	107	+ { KEY_LEFT, "\033[D"},
	108	+};
96	109
	110	+/* Maximum number of output characters that an ANSI sequence expands to */
	111	+#define ANSI_CHAR_MAX 3
	112	+
97	113	int input_queue_ascii(struct input_config *config, int ch)
98	114	{
99	115	if (config->fifo_in + 1 == INPUT_BUFFER_LEN) {
100	116
101	117
102	118
103	119
104	120
105	121
...	...	@@ -289,24 +305,67 @@
289	305	}
290	306
291	307	/**
	308	+ * Checks and converts a special key code into ANSI 3.64 escape sequence.
	309	+ *
	310	+ * @param config Input state
	311	+ * @param keycode Key code to examine
	312	+ * @param output_ch Buffer to place output characters into. It should
	313	+ * be at least ANSI_CHAR_MAX bytes long, to allow for
	314	+ * an ANSI sequence.
	315	+ * @param max_chars Maximum number of characters to add to output_ch
	316	+ * @return number of characters output, if the key was converted, otherwise 0.
	317	+ * This may be larger than max_chars, in which case the overflow
	318	+ * characters are not output.
	319	+ */
	320	+static int input_keycode_to_ansi364(struct input_config *config,
	321	+ int keycode, char output_ch[], int max_chars)
	322	+{
	323	+ const char *escape;
	324	+ int ch_count;
	325	+ int i;
	326	+
	327	+ for (i = ch_count = 0; i < ARRAY_SIZE(kbd_to_ansi364); i++) {
	328	+ if (keycode != kbd_to_ansi364[i].kbd_scan_code)
	329	+ continue;
	330	+ for (escape = kbd_to_ansi364[i].escape; *escape; escape++) {
	331	+ if (ch_count < max_chars)
	332	+ output_ch[ch_count] = *escape;
	333	+ ch_count++;
	334	+ }
	335	+ return ch_count;
	336	+ }
	337	+
	338	+ return 0;
	339	+}
	340	+
	341	+/**
	342	+ * Converts and queues a list of key codes in escaped ASCII string form
292	343	* Convert a list of key codes into ASCII
293	344	*
294	345	* You must call input_check_keycodes() before this. It turns the keycode
295		- * list into a list of ASCII characters which are ready to send to the
296		- * input layer.
	346	+ * list into a list of ASCII characters and sends them to the input layer.
297	347	*
298	348	* Characters which were seen last time do not generate fresh ASCII output.
	349	+ * The output (calls to queue_ascii) may be longer than num_keycodes, if the
	350	+ * keycode contains special keys that was encoded to longer escaped sequence.
299	351	*
300	352	* @param config Input state
301	353	* @param keycode List of key codes to examine
302	354	* @param num_keycodes Number of key codes
	355	+ * @param output_ch Buffer to place output characters into. It should
	356	+ * be at last ANSI_CHAR_MAX * num_keycodes, to allow for
	357	+ * ANSI sequences.
	358	+ * @param max_chars Maximum number of characters to add to output_ch
303	359	* @param same Number of key codes which are the same
	360	+ * @return number of characters written into output_ch, or -1 if we would
	361	+ * exceed max_chars chars.
304	362	*/
305	363	static int input_keycodes_to_ascii(struct input_config *config,
306		- int keycode[], int num_keycodes, char output_ch[], int same)
	364	+ int keycode[], int num_keycodes, char output_ch[],
	365	+ int max_chars, int same)
307	366	{
308	367	struct input_key_xlate *table;
309		- int ch_count;
	368	+ int ch_count = 0;
310	369	int i;
311	370
312	371	table = &config->table[0];
313	372
314	373
315	374
...	...	@@ -321,19 +380,31 @@
321	380	}
322	381	}
323	382
324		- /* now find normal keys */
325		- for (i = ch_count = 0; i < num_keycodes; i++) {
	383	+ /* Start conversion by looking for the first new keycode (by same). */
	384	+ for (i = same; i < num_keycodes; i++) {
326	385	int key = keycode[i];
	386	+ int ch = (key < table->num_entries) ? table->xlate[key] : 0xff;
327	387
328		- if (key < table->num_entries && i >= same) {
329		- int ch = table->xlate[key];
330		-
331		- /* If a normal key with an ASCII value, add it! */
332		- if (ch != 0xff)
333		- output_ch[ch_count++] = (uchar)ch;
	388	+ /*
	389	+ * For a normal key (with an ASCII value), add it; otherwise
	390	+ * translate special key to escape sequence if possible.
	391	+ */
	392	+ if (ch != 0xff) {
	393	+ if (ch_count < max_chars)
	394	+ output_ch[ch_count] = (uchar)ch;
	395	+ ch_count++;
	396	+ } else {
	397	+ ch_count += input_keycode_to_ansi364(config, key,
	398	+ output_ch, max_chars);
334	399	}
335	400	}
336	401
	402	+ if (ch_count > max_chars) {
	403	+ debug("%s: Output char buffer overflow size=%d, need=%d\n",
	404	+ __func__, max_chars, ch_count);
	405	+ return -1;
	406	+ }
	407	+
337	408	/* ok, so return keys */
338	409	return ch_count;
339	410	}
...	...	@@ -341,7 +412,7 @@
341	412	int input_send_keycodes(struct input_config *config,
342	413	int keycode[], int num_keycodes)
343	414	{
344		- char ch[num_keycodes];
	415	+ char ch[num_keycodes * ANSI_CHAR_MAX];
345	416	int count, i, same = 0;
346	417	int is_repeat = 0;
347	418	unsigned delay_ms;
...	...	@@ -363,7 +434,7 @@
363	434	}
364	435
365	436	count = input_keycodes_to_ascii(config, keycode, num_keycodes,
366		- ch, is_repeat ? 0 : same);
	437	+ ch, sizeof(ch), is_repeat ? 0 : same);
367	438	for (i = 0; i < count; i++)
368	439	input_queue_ascii(config, ch[i]);
369	440	delay_ms = is_repeat ?
...	...	@@ -371,7 +442,8 @@
371	442	config->repeat_delay_ms;
372	443
373	444	config->next_repeat_ms = get_timer(0) + delay_ms;
374		- return 0;
	445	+
	446	+ return count;
375	447	}
376	448
377	449	int input_add_table(struct input_config *config, int left_keycode,
...	...	@@ -84,6 +84,8 @@
84	84	* @param config Input state
85	85	* @param keycode List of key codes to examine
86	86	* @param num_keycodes Number of key codes
	87	+ * @return number of ascii characters sent, or 0 if none, or -1 for an
	88	+ * internal error
87	89	*/
88	90	int input_send_keycodes(struct input_config *config, int keycode[], int count);
89	91