rambi: glimmer: Disable key scanning in suspend when lid is open

Added ability to disable the keyboard to wake from suspend when the lid
is outside a certain angle range. This has been added to glimmer by
defining CONFIG_LID_ANGLE_KEY_SCAN in its board.h.

Also modified the lid angle calculation to include a reliability
flag which can be used to tell when the hinge aligns too closely
with gravity and the lid angle value is unreliable.

BUG=none
BRANCH=rambi
TEST=Tested on a glimmer:

In S3, verified that when the lid is open past ~180 deg, the keyboard
does not wake the machine. Also verified that if you align hinge with
gravity, the keyboard enabled/disabled status remains the same (since
we can't actually trust the lid angle value).

Change-Id: I45b2c7c3c4bbcae61d3a0f8b5baa461ab8dabfb0
Original-Change-Id: If1a1592d259902d38941936961854b81b3a75b95
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/190061
Reviewed-on: https://chromium-review.googlesource.com/191612
Reviewed-by: Randall Spangler <rspangler@chromium.org>

5 files changed, 40 insertions, 0 deletions

diff --git a/include/config.h b/include/config.h
index 300126a6cf..68402985ec 100644
--- a/include/config.h
+++ b/include/config.h
@@ -559,6 +559,17 @@
 #undef CONFIG_LED_DRIVER_LP5562  /* LP5562, on I2C interface */
 
 /*
+ * Allows using the lid angle measurement to determine if key scanning should
+ * be enabled or disabled when chipset is suspended.
+ *
+ * Any board that defines this must also define two macros:
+ * LID_IN_RANGE_TO_ACCEPT_KEYS(angle), LID_IN_RANGE_TO_IGNORE_KEYS(angle).
+ * These macros should return true if the given angle argument is in range
+ * to accept or ignore key presses.
+ */
+#undef CONFIG_LID_ANGLE_KEY_SCAN
+
+/*
  * Compile lid switch support.
  *
  * This is enabled by default because all boards other than reference boards
diff --git a/include/console.h b/include/console.h
index 8106e54f56..a6cce1fa8c 100644
--- a/include/console.h
+++ b/include/console.h
@@ -39,6 +39,7 @@ enum console_channel {
 	CC_I2C,
 	CC_KEYBOARD,
 	CC_KEYSCAN,
+	CC_LIDANGLE,
 	CC_LIGHTBAR,
 	CC_LPC,
 	CC_MOTION_SENSE,
diff --git a/include/keyboard_scan.h b/include/keyboard_scan.h
index bc956cc685..8359cbd174 100644
--- a/include/keyboard_scan.h
+++ b/include/keyboard_scan.h
@@ -84,6 +84,11 @@ void keyboard_scan_enable(int enable);
 static inline void keyboard_scan_enable(int enable) { }
 #endif
 
+/**
+ * Returns if keyboard matrix scanning is enabled/disabled.
+ */
+int keyboard_scan_is_enabled(void);
+
 #ifdef CONFIG_KEYBOARD_SUPPRESS_NOISE
 /**
  * Indicate to audio codec that a key has been pressed.
diff --git a/include/lid_angle.h b/include/lid_angle.h
new file mode 100644
index 0000000000..bd60b90907
--- /dev/null
+++ b/include/lid_angle.h
@@ -0,0 +1,20 @@
+/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Lid angle module for Chrome EC */
+
+#ifndef __CROS_EC_LID_ANGLE_H
+#define __CROS_EC_LID_ANGLE_H
+
+/**
+ * Update the lid angle module with the most recent lid angle calculation. Then
+ * use the lid angle history to enable/disable keyboard scanning when chipset
+ * is suspended.
+ *
+ * @lid_ang Lid angle.
+ */
+void lidangle_keyscan_update(float lid_ang);
+
+#endif  /* __CROS_EC_LID_ANGLE_H */
diff --git a/include/motion_sense.h b/include/motion_sense.h
index 08aefbcc0b..d0c2774254 100644
--- a/include/motion_sense.h
+++ b/include/motion_sense.h
@@ -11,6 +11,9 @@
 #include "gpio.h"
 #include "math_util.h"
 
+/* Anything outside of lid angle range [-180, 180] should work. */
+#define LID_ANGLE_UNRELIABLE 500.0F
+
 /**
  * This structure defines all of the data needed to specify the orientation
  * of the base and lid accelerometers in order to calculate the lid angle.