zephyr: DT: support sensor rotation matrix

This creates instances of rotation matrix(mat33_fp_t)
which is used to convert raw value from a sensor to X, Y and
Z on the defined coordinate system.

BUG=b:173507858
BRANCH=none
TEST=make buildall -j8
build volteer on zephyr

Signed-off-by: Hyungwoo Yang <hyungwoo.yang@intel.corp-partner.google.com>
Change-Id: Ifc80fe7ff33c46904af279b9f52e611c7157c346
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2778814
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 81 insertions, 0 deletions

diff --git a/zephyr/dts/bindings/motionsense/cros-ec,motionsense-rotation-ref.yaml b/zephyr/dts/bindings/motionsense/cros-ec,motionsense-rotation-ref.yaml
new file mode 100644
index 0000000000..7de86ec8db
--- /dev/null
+++ b/zephyr/dts/bindings/motionsense/cros-ec,motionsense-rotation-ref.yaml
@@ -0,0 +1,55 @@
+# Copyright 2021 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.
+
+description: rotation reference parent node
+
+compatible: "cros-ec,motionsense-rotation-ref"
+
+child-binding:
+  description: |
+    A rotation matrix node is used to create
+    an instance of mat33_fp_t which is used by
+    sensor drivers.
+  properties:
+    mat33:
+      required: true
+      type: array
+      description: |
+        3x3 matrix to rotate x, y, and z axes.
+        Applications with the sensor API expects sansor data
+        based on the same defined coordinate system.
+        * X-axis is horizontal and positive toward the right
+        * Y-axis is vertical and positive toward the top
+        * Z-axis points toward the user
+
+        Depending on how the sensor is mounted on board(PCB), we
+        may need to change the direction of a axis and swap X and
+        Y-axis. Using the 3x3 matrix, it generates the correct
+        X,Y, and Z on the defined coordinate system.
+
+        +-        -+   +-        -+   +- -+
+        | v1 v2 v3 |   | sensor_X |   | X |
+        | v4 v5 v6 | * | sensor_Y | = | Y |
+        | v7 v8 v9 |   | sensor_Z |   | Z |
+        +-        -+   +-        -+   +- -+
+
+#
+# examples:
+#
+# motionsense-rotation-ref {
+#        compatible = "cros-ec,motionsense-rotation-ref";
+#        /* change the direction of Y and Z-axis */
+#        lid_rot_ref: lid-rotation-ref {
+#                mat33 = <1 0 0
+#                         0 (-1) 0
+#                         0 0 (-1)>;
+#        };
+#        /* swap X and Y-axis, and then change the direction of Y-axis */
+#        base_rot_ref: base-rotation-ref {
+#                mat33 = <0 1 0
+#                         (-1) 0 0
+#                         0 0 1>;
+#        };
+# };
+#
diff --git a/zephyr/shim/src/motionsense_sensors.c b/zephyr/shim/src/motionsense_sensors.c
index 681ebcce6b..9e8eef6f6f 100644
--- a/zephyr/shim/src/motionsense_sensors.c
+++ b/zephyr/shim/src/motionsense_sensors.c
@@ -31,3 +31,29 @@ static int init_sensor_mutex(const struct device *dev)
 }
 SYS_INIT(init_sensor_mutex, POST_KERNEL, 50);
 #endif /* DT_NODE_EXISTS(SENSOR_MUTEX_NODE) */
+
+#define SENSOR_ROT_REF_NODE		DT_PATH(motionsense_rotation_ref)
+#define SENSOR_ROT_STD_REF_NAME(id)	DT_CAT(ROT_REF_, id)
+#define MAT_ITEM(i, id)	FLOAT_TO_FP((int32_t)(DT_PROP_BY_IDX(id, mat33, i)))
+#define DECLARE_SENSOR_ROT_REF(id)					\
+	static const mat33_fp_t SENSOR_ROT_STD_REF_NAME(id) = {	\
+		{							\
+			FOR_EACH_FIXED_ARG(MAT_ITEM, (,), id, 0, 1, 2)	\
+		},							\
+		{							\
+			FOR_EACH_FIXED_ARG(MAT_ITEM, (,), id, 3, 4, 5)	\
+		},							\
+		{							\
+			FOR_EACH_FIXED_ARG(MAT_ITEM, (,), id, 6, 7, 8)	\
+		},							\
+	};
+
+/*
+ * Declare 3x3 rotation matrix for
+ * each child node of "/motionsense-rotation-ref" node in DT.
+ *
+ * A rotation matrix can be shared among the motion sensors.
+ */
+#if DT_NODE_EXISTS(SENSOR_ROT_REF_NODE)
+DT_FOREACH_CHILD(SENSOR_ROT_REF_NODE, DECLARE_SENSOR_ROT_REF)
+#endif