serial: efi-stdio: Add simple_text_input_ex_protocol backend

EFI implementations differ in how simple_text_input_protocol treats
ctrl+alpha combinations. OVMF (used with QEMU) returns a Unicode control
character, the UEFI on the Dell Latitude 7490 on the other hand ignores
the ctrl completely and returns just the letter rendering utilities
like barebox edit unusable.

To fix this, the simple_text_input_ex_protocol can be leveraged as it
additionally provides the state of modifier keys. Extend efi-stdio to use
it where possible.

Cc: Michael Olbrich <mol@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 58 insertions, 0 deletions

diff --git a/drivers/serial/efi-stdio.h b/drivers/serial/efi-stdio.h
new file mode 100644
index 0000000000..1fa417c706
--- /dev/null
+++ b/drivers/serial/efi-stdio.h
@@ -0,0 +1,58 @@
+#ifndef EFI_STDIO_H_
+#define EFI_STDIO_H_
+
+#include <efi.h>
+
+struct efi_simple_text_input_ex_protocol;
+
+typedef efi_status_t (EFIAPI *efi_input_reset_ex)(
+	struct efi_simple_text_input_ex_protocol *this,
+	efi_bool_t extended_verification
+);
+
+struct efi_key_state {
+	u32 shift_state;
+	u8 toggle_state;
+};
+
+struct efi_key_data {
+	struct efi_input_key key;
+	struct efi_key_state state;
+};
+
+typedef efi_status_t (EFIAPI *efi_input_read_key_ex)(
+	struct efi_simple_text_input_ex_protocol *this,
+	struct efi_key_data *keydata
+);
+
+typedef efi_status_t (EFIAPI *efi_set_state)(
+	struct efi_simple_text_input_ex_protocol *this,
+	u8 *key_toggle_state
+);
+
+typedef efi_status_t (EFIAPI *efi_key_notify_function)(
+	struct efi_key_data *keydata
+);
+
+typedef efi_status_t (EFIAPI *efi_register_keystroke_notify)(
+	struct efi_simple_text_input_ex_protocol *this,
+	struct efi_key_data keydata,
+	efi_key_notify_function key_notification_function,
+	void **notify_handle
+);
+
+typedef efi_status_t (EFIAPI *efi_unregister_keystroke_notify)(
+	struct efi_simple_text_input_ex_protocol *this,
+	void *notification_handle
+);
+
+struct efi_simple_text_input_ex_protocol {
+	efi_input_reset_ex reset;
+	efi_input_read_key_ex read_key_stroke_ex;
+	void *wait_for_key_ex;
+	efi_set_state set_state;
+	efi_register_keystroke_notify register_key_notify;
+	efi_unregister_keystroke_notify unregister_key_notify;
+};
+
+#endif