[PATCH v2 24/39] efi: serial: Support arrow keys

[Heinrich Schuchardt]

On 9/25/21 2:30 AM, Simon Glass wrote:
> 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 at 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;

All 23 EFI Scan Codes should be supported. Can't we use something like
kbd_to_ansi364[] from drivers/input/input.c to create the appropriate
escape sequences?

Best regards

Heinrich

> +	}
>   	debug(" [%x %x %x] ", ch, priv->key.unicode_char, priv->key.scan_code);
>
>   	return ch;
>