[U-Boot] [PATCH 5/5] input: Add ANSI 3.64 escape sequence generation.
Simon Glass
sjg at chromium.org
Fri Oct 12 03:15:53 CEST 2012
From: Hung-Te Lin <hungte at chromium.org>
To support Non-ASCII keys (ex, Fn, PgUp/Dn, arrow keys, ...), we need to
translate key code into escape sequence.
(Updated by sjg at 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 at chromium.org>
Signed-off-by: Simon Glass <sjg at chromium.org>
---
drivers/input/input.c | 102 +++++++++++++++++++++++++++++++++++++++++-------
include/input.h | 2 +
2 files changed, 89 insertions(+), 15 deletions(-)
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 5b2b4b0..9800667 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -93,6 +93,22 @@ static unsigned char kbd_ctrl_xlate[] = {
'\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)
{
@@ -289,24 +305,67 @@ static int input_check_keycodes(struct input_config *config,
}
/**
+ * 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 @@ static int input_keycodes_to_ascii(struct input_config *config,
}
}
- /* 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 @@ static int input_keycodes_to_ascii(struct input_config *config,
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 @@ int input_send_keycodes(struct input_config *config,
}
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 @@ int input_send_keycodes(struct input_config *config,
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,
diff --git a/include/input.h b/include/input.h
index 0f4acb2..e90bb0b 100644
--- a/include/input.h
+++ b/include/input.h
@@ -84,6 +84,8 @@ struct stdio_dev;
* @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);
--
1.7.7.3
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