common: Add new recovery mode button combination

This adds new key combination (Left_Shift+Esc+Refresh+Power) that triggers
recovery mode by setting a new host event
EC_HOST_EVENT_KEYBOARD_RECOVERY_HW_REINIT. This host event can be used
whenever user wants to request entry into recovery mode by
reinitializing all the hardware state (e.g. memory retraining).

BUG=chrome-os-partner:56643,chrome-os-partner:59352
BRANCH=None
TEST=Verified that device retrains memory in recovery mode
with (Left_Shift+Esc+Refresh+Power) on reef.

Change-Id: I2e08997acfd9e22270b8ce7a5b589cd5630645f8
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/407827
Reviewed-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 16 insertions, 9 deletions

diff --git a/include/keyboard_scan.h b/include/keyboard_scan.h
index 41cdbdf611..faba74ffe1 100644
--- a/include/keyboard_scan.h
+++ b/include/keyboard_scan.h
@@ -49,21 +49,28 @@ extern struct keyboard_scan_config keyscan_config;
 
 /* Key held down at keyboard-controlled reset boot time. */
 enum boot_key {
-	BOOT_KEY_NONE,  /* No keys other than keyboard-controlled reset keys */
-	BOOT_KEY_ESC,
-	BOOT_KEY_DOWN_ARROW,
-	BOOT_KEY_OTHER = -1,  /* None of the above */
+	/* No keys other than keyboard-controlled reset keys */
+	BOOT_KEY_NONE = 0,
+	BOOT_KEY_ESC = (1 << 0),
+	BOOT_KEY_DOWN_ARROW = (1 << 1),
+	BOOT_KEY_LEFT_SHIFT = (1 << 2),
 };
 
 #ifdef HAS_TASK_KEYSCAN
 /**
- * Return the key held down at boot time in addition to the keyboard-controlled
- * reset keys.  Returns BOOT_KEY_OTHER if none of the keys specifically checked
- * was pressed, or reset was not caused by a keyboard-controlled reset.
+ * Returns mask of all the keys held down at boot time in addition to the
+ * keyboard-controlled reset keys. If more than one boot key is held, mask bits
+ * will be set for each of those keys. Since more than one bit can be set,
+ * caller needs to ensure that boot keys match as intended.
+ *
+ * Returns BOOT_NONE if no additional key is held or if none of the keys
+ * specifically checked was pressed, or reset was not caused by a
+ * keyboard-controlled reset or if any key *other* than boot keys, power, or
+ * refresh is also pressed.
  */
-enum boot_key keyboard_scan_get_boot_key(void);
+uint32_t keyboard_scan_get_boot_keys(void);
 #else
-static inline enum boot_key keyboard_scan_get_boot_key(void)
+static inline uint32_t keyboard_scan_get_boot_keys(void)
 {
 	return BOOT_KEY_NONE;
 }