# 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>;
#        };
# };
#