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>

diff --git a/drivers/input/input.c b/drivers/input/input.c
index 5b2b4b0714d8b0d1761601e4d8a1f25b5a4b8de9..98006679b30f28cb8b48f8a0ca6ef1d096925a38 100644 (file)
--- 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 0f4acb27f83782a70d1e5aa75c3782fffe7d6b20..e90bb0ba9c6c4505c90de44be5e4a37a68256ef0 100644 (file)
--- 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);