libpayload-x86: Export keyboard modifiers

Add function to get active keyboard modifiers.

Change-Id: Ifc7bd4aa86f20d67c5b542d0458b966e605c5499
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/18601
Reviewed-by: Martin Roth <martinroth@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 41 insertions, 27 deletions

diff --git a/payloads/libpayload/drivers/i8042/keyboard.c b/payloads/libpayload/drivers/i8042/keyboard.c
index a24d5a22cb..af44e016ee 100644
--- a/payloads/libpayload/drivers/i8042/keyboard.c
+++ b/payloads/libpayload/drivers/i8042/keyboard.c
@@ -41,6 +41,7 @@ struct layout_maps {
 };
 
 static struct layout_maps *map;
+static int modifier = 0;
 
 static struct layout_maps keyboard_layouts[] = {
 #if IS_ENABLED(CONFIG_LP_PC_KEYBOARD_LAYOUT_US)
@@ -158,11 +159,6 @@ static struct layout_maps keyboard_layouts[] = {
 #endif
 };
 
-#define MOD_SHIFT    (1 << 0)
-#define MOD_CTRL     (1 << 1)
-#define MOD_CAPSLOCK (1 << 2)
-#define MOD_ALT      (1 << 3)
-
 static unsigned char keyboard_cmd(unsigned char cmd)
 {
 	i8042_write_data(cmd);
@@ -177,71 +173,81 @@ int keyboard_havechar(void)
 
 unsigned char keyboard_get_scancode(void)
 {
-	return i8042_read_data_ps2();
-}
-
-int keyboard_getchar(void)
-{
-	static int modifier = 0;
 	unsigned char ch;
-	int shift;
-	int ret = 0;
 
 	while (!keyboard_havechar()) ;
 
-	ch = keyboard_get_scancode();
+	ch = i8042_read_data_ps2();
 
 	switch (ch) {
 	case 0x36:
 	case 0x2a:
-		modifier |= MOD_SHIFT;
+		modifier |= KB_MOD_SHIFT;
 		break;
 	case 0x80 | 0x36:
 	case 0x80 | 0x2a:
-		modifier &= ~MOD_SHIFT;
+		modifier &= ~KB_MOD_SHIFT;
 		break;
 	case 0x38:
-		modifier |= MOD_ALT;
+		modifier |= KB_MOD_ALT;
 		break;
 	case 0x80 | 0x38:
-		modifier &= ~MOD_ALT;
+		modifier &= ~KB_MOD_ALT;
 		break;
 	case 0x1d:
-		modifier |= MOD_CTRL;
+		modifier |= KB_MOD_CTRL;
 		break;
 	case 0x80 | 0x1d:
-		modifier &= ~MOD_CTRL;
+		modifier &= ~KB_MOD_CTRL;
 		break;
 	case 0x3a:
-		if (modifier & MOD_CAPSLOCK) {
-			modifier &= ~MOD_CAPSLOCK;
+		if (modifier & KB_MOD_CAPSLOCK) {
+			modifier &= ~KB_MOD_CAPSLOCK;
 			if (keyboard_cmd(0xed))
 				keyboard_cmd(0 << 2);
 		} else {
-			modifier |= MOD_CAPSLOCK;
+			modifier |= KB_MOD_CAPSLOCK;
 			if (keyboard_cmd(0xed))
 				keyboard_cmd(1 << 2);
 		}
 		break;
 	}
 
+	return ch;
+}
+
+int keyboard_getmodifier(void)
+{
+	return modifier;
+}
+
+int keyboard_getchar(void)
+{
+	unsigned char ch;
+	int shift;
+	int ret = 0;
+
+	while (!keyboard_havechar()) ;
+
+	ch = keyboard_get_scancode();
+
 	if (!(ch & 0x80) && ch < 0x57) {
 		shift =
-		    (modifier & MOD_SHIFT) ^ (modifier & MOD_CAPSLOCK) ? 1 : 0;
+		    (modifier & KB_MOD_SHIFT) ^ (modifier & KB_MOD_CAPSLOCK) ? 1 : 0;
 
-		if (modifier & MOD_ALT)
+		if (modifier & KB_MOD_ALT)
 			shift += 2;
 
 		ret = map->map[shift][ch];
 
-		if (modifier & MOD_CTRL) {
+		if (modifier & KB_MOD_CTRL) {
 			switch (ret) {
 			case 'a' ... 'z':
 				ret &= 0x1f;
 				break;
 			case KEY_DC:
 				/* vulcan nerve pinch */
-				if ((modifier & MOD_ALT) && reset_handler)
+				if ((modifier & KB_MOD_ALT) && reset_handler)
 					reset_handler();
 			default:
 				ret = 0;
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index e74006a90f..359bd0e4ce 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -163,6 +163,14 @@ int keyboard_havechar(void);
 unsigned char keyboard_get_scancode(void);
 int keyboard_getchar(void);
 int keyboard_set_layout(char *country);
+int keyboard_getmodifier(void);
+
+enum KEYBOARD_MODIFIERS {
+	KB_MOD_SHIFT = (1 << 0),
+	KB_MOD_ALT = (1 << 1),
+	KB_MOD_CTRL = (1 << 2),
+	KB_MOD_CAPSLOCK = (1 << 3),
+};
 /** @} */
 
 /**