nissa: Allow alternate rotation parameters for nivviks

If the FW_CONFIG indicates an inverted form factor,
switch the rotation parameters to an alternate set.
This is to support different form factors for nivviks.

BUG=b:226486185
TEST=zmake build nivviks; flash run, adjust CBI, check screen
BRANCH=none

Signed-off-by: Andrew McRae <amcrae@google.com>
Cq-Depend: chromium:3561599
Change-Id: I92f26f16962bee250fe57651d2ffa499877dac9e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3563383
Reviewed-by: Peter Marheine <pmarheine@chromium.org>

5 files changed, 78 insertions, 3 deletions

diff --git a/zephyr/projects/nissa/CMakeLists.txt b/zephyr/projects/nissa/CMakeLists.txt
index b22422d4ef..715fd3680d 100644
--- a/zephyr/projects/nissa/CMakeLists.txt
+++ b/zephyr/projects/nissa/CMakeLists.txt
@@ -14,6 +14,7 @@ zephyr_library_sources_ifdef(CONFIG_AP_PWRSEQ "src/board_power.c")
 
 if(DEFINED CONFIG_BOARD_NIVVIKS)
 	project(nivviks)
+	zephyr_library_sources("src/nivviks/form_factor.c")
 	zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_USBC "src/nivviks/usbc.c")
 	zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CHARGER "src/nivviks/charger.c")
 endif()
diff --git a/zephyr/projects/nissa/nivviks_motionsense.dts b/zephyr/projects/nissa/nivviks_motionsense.dts
index ac5d4c390c..f14cadcb3d 100644
--- a/zephyr/projects/nissa/nivviks_motionsense.dts
+++ b/zephyr/projects/nissa/nivviks_motionsense.dts
@@ -42,6 +42,12 @@
 				 0 0 (-1)>;
 		};
 
+		base_rot_inverted: base-rot-inverted {
+			mat33 = <(-1) 0 0
+				 0 1 0
+				 0 0 (-1)>;
+		};
+
 		base_rot_ref: base-rotation-ref {
 			mat33 = <1 0 0
 				 0 (-1) 0
@@ -85,6 +91,10 @@
 			location = "MOTIONSENSE_LOC_BASE";
 			mutex = <&base_mutex>;
 			port = <&i2c_ec_i2c_sensor>;
+			/*
+			 * May be replaced by alternate depending
+			 * on board config.
+			 */
 			rot-standard-ref = <&base_rot_ref>;
 			drv-data = <&lsm6dso_data>;
 			configs {
diff --git a/zephyr/projects/nissa/src/nivviks/form_factor.c b/zephyr/projects/nissa/src/nivviks/form_factor.c
new file mode 100644
index 0000000000..99ac7f65b8
--- /dev/null
+++ b/zephyr/projects/nissa/src/nivviks/form_factor.c
@@ -0,0 +1,48 @@
+/* Copyright 2022 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.
+ */
+
+#include <devicetree.h>
+#include <init.h>
+#include <logging/log.h>
+
+#include "accelgyro.h"
+#include "cros_cbi.h"
+#include "hooks.h"
+#include "motionsense_sensors.h"
+
+#include "nissa_common.h"
+
+LOG_MODULE_DECLARE(nissa, CONFIG_NISSA_LOG_LEVEL);
+
+/*
+ * Mainboard orientation support.
+ */
+
+#define ALT_MAT		SENSOR_ROT_STD_REF_NAME(DT_NODELABEL(base_rot_inverted))
+#define BASE_SENSOR	SENSOR_ID(DT_NODELABEL(base_accel))
+
+static int form_factor_init(const struct device *unused)
+{
+	int ret;
+	uint32_t val;
+	/*
+	 * If the firmware config indicates
+	 * an inverted form factor, use the alternative
+	 * rotation matrix.
+	 */
+	ret = cros_cbi_get_fw_config(FW_BASE_INVERSION, &val);
+	if (ret != 0) {
+		LOG_ERR("Error retrieving CBI FW_CONFIG field %d",
+			FW_BASE_INVERSION);
+		return 0;
+	}
+	if (val == FW_BASE_INVERTED) {
+		LOG_INF("Switching to inverted base");
+		motion_sensors[BASE_SENSOR].rot_standard_ref = &ALT_MAT;
+	}
+	return 0;
+}
+
+SYS_INIT(form_factor_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);
diff --git a/zephyr/shim/include/motionsense_sensors.h b/zephyr/shim/include/motionsense_sensors.h
index e4ecf5d6de..0add50914a 100644
--- a/zephyr/shim/include/motionsense_sensors.h
+++ b/zephyr/shim/include/motionsense_sensors.h
@@ -12,6 +12,24 @@
 extern struct motion_sensor_t motion_sensors_alt[];
 
 /*
+ * Common macros.
+ */
+#define SENSOR_ROT_STD_REF_NAME(id)	DT_CAT(ROT_REF_, id)
+#define SENSOR_ROT_REF_NODE		DT_PATH(motionsense_rotation_ref)
+
+/*
+ * Declare rotation parameters, since they may be
+ * dynamically selected.
+ */
+#define DECLARE_EXTERN_SENSOR_ROT_REF(id)				\
+	extern const mat33_fp_t SENSOR_ROT_STD_REF_NAME(id);
+
+#if DT_NODE_EXISTS(SENSOR_ROT_REF_NODE)
+DT_FOREACH_CHILD(SENSOR_ROT_REF_NODE, DECLARE_EXTERN_SENSOR_ROT_REF)
+#endif
+#undef DECLARE_EXTERN_SENSOR_ROT_REF
+
+/*
  * Performs probing of an alternate sensor.
  * @param alt_idx Index in motion_sensors_alt of the sensor to be probed.
  *		  It should be gained with SENSOR_ID,
diff --git a/zephyr/shim/src/motionsense_sensors.c b/zephyr/shim/src/motionsense_sensors.c
index 0cc55339df..c720e8434e 100644
--- a/zephyr/shim/src/motionsense_sensors.c
+++ b/zephyr/shim/src/motionsense_sensors.c
@@ -28,11 +28,9 @@ LOG_MODULE_REGISTER(shim_cros_motionsense_sensors);
 DT_FOREACH_CHILD(SENSOR_MUTEX_NODE, DECLARE_SENSOR_MUTEX)
 #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) = {	\
+	const mat33_fp_t SENSOR_ROT_STD_REF_NAME(id) = {	\
 		{							\
 			FOR_EACH_FIXED_ARG(MAT_ITEM, (,), id, 0, 1, 2)	\
 		},							\