[coreboot-gerrit] Change in coreboot[master]: libpayload: keyboard: Ignore special keys

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/36654 )

Change subject: libpayload: keyboard: Ignore special keys
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libpayload: keyboard: Ignore special keys

Some special keys emit a prefix scan code 0xE0. We will ignore all
these except for the power button, F12 and cursor keys on drallion.

Media key mapping is set in depthcharge and will be sent to libpayload
keyboard driver. Whichever board requires this change will update its own
media key mapping.

BUG:b:139511038
TEST=boot in recovery mode, press F12 to go to diagnostic mode and power
button to confirm. Also in recovery mode left arrow, right arrow, up arrow,
down arrow changes the language on the firmware screen.

Change-Id: I1c11939d18391bebe53ca21cf33a096ba369cd56
Signed-off-by: Thejaswani Putta 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36654
Reviewed-by: EricR Lai 
Reviewed-by: Mathew King 
Tested-by: build bot (Jenkins) 
---
M payloads/libpayload/drivers/i8042/keyboard.c
M payloads/libpayload/include/libpayload.h
2 files changed, 12 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  EricR Lai: Looks good to me, approved
  Mathew King: Looks good to me, approved

diff --git a/payloads/libpayload/drivers/i8042/keyboard.c b/payloads/libpayload/drivers/i8042/keyboard.c
index 48d35a0..f9932ed 100644
--- a/payloads/libpayload/drivers/i8042/keyboard.c
+++ b/payloads/libpayload/drivers/i8042/keyboard.c
@@ -35,6 +35,7 @@
 #include "i8042.h"

#define POWER_BUTTON         0x90
+#define MEDIA_KEY_PREFIX     0xE0

struct layout_maps {
    const char *country;
@@ -43,6 +44,7 @@

static struct layout_maps *map;
 static int modifier = 0;
+int (*media_key_mapping_callback)(char ch);

static struct layout_maps keyboard_layouts[] = {
 #if CONFIG(LP_PC_KEYBOARD_LAYOUT_US)
@@ -230,6 +232,11 @@
    return modifier;
 }

+void initialize_keyboard_media_key_mapping_callback(int (*media_key_mapper)(char))
+{
+	media_key_mapping_callback = media_key_mapper;
+}
+
 int keyboard_getchar(void)
 {
    unsigned char ch;
@@ -239,6 +246,10 @@
    while (!keyboard_havechar()) ;

ch = keyboard_get_scancode();
+	if ((media_key_mapping_callback != NULL) && (ch == MEDIA_KEY_PREFIX)) {
+		ch = keyboard_get_scancode();
+		return media_key_mapping_callback(ch);
+	}

if (!(ch & 0x80) && ch < 0x59) {
    	shift =
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 80bfaae..bfe9da5 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -187,6 +187,7 @@
 int keyboard_getchar(void);
 int keyboard_set_layout(char *country);
 int keyboard_getmodifier(void);
+void initialize_keyboard_media_key_mapping_callback(int (*media_key_mapper)(char));

enum KEYBOARD_MODIFIERS {
    KB_MOD_SHIFT = (1 << 0),