[PATCH v3 18/35] efi: serial: Support arrow keys

[Simon Glass <sjg@chromium.org>]

At present only the backspace key is supported in U-Boot, when running as
an EFI app. Add support for arrows, home and end as well, to make the CLI
more friendly.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

(no changes since v1)

 drivers/serial/serial_efi.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/serial/serial_efi.c b/drivers/serial/serial_efi.c
index 33ddbd6080c..0067576389d 100644
--- a/drivers/serial/serial_efi.c
+++ b/drivers/serial/serial_efi.c
@@ -24,6 +24,9 @@ struct serial_efi_priv {
 	bool have_key;
 };
 
+/* Convert a lower-case character to its ctrl-char equivalent */
+#define CTL_CH(c)		((c) - 'a' + 1)
+
 int serial_efi_setbrg(struct udevice *dev, int baudrate)
 {
 	return 0;
@@ -49,6 +52,7 @@ static int serial_efi_get_key(struct serial_efi_priv *priv)
 static int serial_efi_getc(struct udevice *dev)
 {
 	struct serial_efi_priv *priv = dev_get_priv(dev);
+	char conv_scan[10] = {0, 'p', 'n', 'f', 'b', 'a', 'e', 0, 8};
 	int ret, ch;
 
 	ret = serial_efi_get_key(priv);
@@ -63,8 +67,11 @@ static int serial_efi_getc(struct udevice *dev)
 	 * key scan code of 8. Handle this so that backspace works correctly
 	 * in the U-Boot command line.
 	 */
-	if (!ch && priv->key.scan_code == 8)
-		ch = 8;
+	if (!ch && priv->key.scan_code < sizeof(conv_scan)) {
+		ch = conv_scan[priv->key.scan_code];
+		if (ch >= 'a')
+			ch -= 'a' - 1;
+	}
 	debug(" [%x %x %x] ", ch, priv->key.unicode_char, priv->key.scan_code);
 
 	return ch;
-- 
2.33.0.1079.g6e70778dc9-goog