zephyr: sensors: Add alternate sensors support

In some boards there's a runtime decision for which sensor to use. In
order to support this we'll need an instance of the alternate sensors
as well as a mapping for them.

Add an optional phandle `alternate-for` to the base sensors bindings.
When used, the sensor will be excluded from the primary
motion_sensors array and added instead to the motion_sensors_alt
array.

BRANCH=none
BUG=b:183990188, b:185966444
TEST=zmake testall

Signed-off-by: Yuval Peress <peress@chromium.org>
Change-Id: I6f6e3a9659a381c45fd97fbce9fecb2a807f7fa2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2846415
Reviewed-by: Keith Short <keithshort@chromium.org>
Commit-Queue: Keith Short <keithshort@chromium.org>

3 files changed, 66 insertions, 7 deletions

diff --git a/zephyr/dts/bindings/motionsense/motionsense-sensor-base.yaml b/zephyr/dts/bindings/motionsense/motionsense-sensor-base.yaml
index e6325a3ef1..9e8b7be2c3 100644
--- a/zephyr/dts/bindings/motionsense/motionsense-sensor-base.yaml
+++ b/zephyr/dts/bindings/motionsense/motionsense-sensor-base.yaml
@@ -54,6 +54,10 @@ properties:
     type: phandle
     required: false
     description: phandle to driver data to be used for the motion sensor
+  alternate-for:
+    type: phandle
+    description: phandle to another sensor that can be swapped with this one
+      at runtime.
 
 #
 # examples:
diff --git a/zephyr/shim/include/motionsense_sensors.h b/zephyr/shim/include/motionsense_sensors.h
index 013a03d8dc..bf7ff95f85 100644
--- a/zephyr/shim/include/motionsense_sensors.h
+++ b/zephyr/shim/include/motionsense_sensors.h
@@ -10,10 +10,17 @@
 
 #define SENSOR_NODE			DT_PATH(motionsense_sensor)
 #define SENSOR_INFO_NODE		DT_PATH(motionsense_sensor_info)
+#define SENSOR_ALT_NODE			DT_PATH(motionsesne_sensor_alt)
 
 #define SENSOR_ID(id)			DT_CAT(SENSOR_, id)
-#define SENSOR_ID_WITH_COMMA(id)					\
-	IF_ENABLED(DT_NODE_HAS_STATUS(id, okay), (SENSOR_ID(id),))
+
+/* Define the SENSOR_ID if:
+ * DT_NODE_HAS_STATUS(id, okay) && !DT_NODE_HAS_PROP(id, alternate_for)
+ */
+#define SENSOR_ID_WITH_COMMA(id)                                     \
+	IF_ENABLED(DT_NODE_HAS_STATUS(id, okay),                     \
+		   (COND_CODE_0(DT_NODE_HAS_PROP(id, alternate_for), \
+				(SENSOR_ID(id), ), ())))
 
 enum sensor_id {
 #if DT_NODE_EXISTS(SENSOR_NODE)
@@ -22,6 +29,21 @@ enum sensor_id {
 	SENSOR_COUNT,
 };
 
+#undef SENSOR_ID_WITH_COMMA
+/* Define the SENSOR_ID if:
+ * DT_NODE_HAS_STATUS(id, okay) && DT_NODE_HAS_PROP(id, alternate_for)
+ */
+#define SENSOR_ID_WITH_COMMA(id)                                     \
+	IF_ENABLED(DT_NODE_HAS_STATUS(id, okay),                     \
+		   (COND_CODE_1(DT_NODE_HAS_PROP(id, alternate_for), \
+				(SENSOR_ID(id), ), ())))
+enum sensor_alt_id {
+#if DT_NODE_EXISTS(SENSOR_ALT_NODE)
+	DT_FOREACH_CHILD(SENSOR_ALT_NODE, SENSOR_ID_WITH_COMMA)
+#endif
+	SENSOR_ALT_COUNT,
+};
+
 /*
  * Find the accelerometers for lid angle calculation.
  *
diff --git a/zephyr/shim/src/motionsense_sensors.c b/zephyr/shim/src/motionsense_sensors.c
index 0a74595ce3..bac92e58e8 100644
--- a/zephyr/shim/src/motionsense_sensors.c
+++ b/zephyr/shim/src/motionsense_sensors.c
@@ -94,7 +94,7 @@ DT_FOREACH_CHILD(SENSOR_ROT_REF_NODE, DECLARE_SENSOR_ROT_REF)
 		compat, create_data_macro)
 
 /*
- * sensor_drv_list.inc is included two times in this file. This is the first
+ * sensor_drv_list.inc is included three times in this file. This is the first
  * time and it is for creating sensor driver-specific data. So we ignore
  * CREATE_MOTION_SENSOR() that creates motion sensor at this time.
  */
@@ -209,10 +209,23 @@ DT_FOREACH_CHILD(SENSOR_ROT_REF_NODE, DECLARE_SENSOR_ROT_REF)
 		.max_frequency = s_max_freq				\
 	},
 
-#define MK_SENSOR_ENTRY(inst, s_compat, s_chip, s_type, s_drv,		\
-		s_min_freq, s_max_freq)					\
-	DO_MK_SENSOR_ENTRY(DT_INST(inst, s_compat),			\
-		s_chip, s_type, s_drv, s_min_freq, s_max_freq)
+/* Construct an entry iff the alternate_for property is missing. */
+#define MK_SENSOR_ENTRY(inst, s_compat, s_chip, s_type, s_drv, s_min_freq,    \
+			s_max_freq)                                           \
+	COND_CODE_0(DT_NODE_HAS_PROP(DT_INST(inst, s_compat), alternate_for), \
+		    (DO_MK_SENSOR_ENTRY(DT_INST(inst, s_compat), s_chip,      \
+					s_type, s_drv, s_min_freq,            \
+					s_max_freq)),                         \
+		    ())
+
+/* Construct an entry iff the alternate_for property exists. */
+#define MK_SENSOR_ALT_ENTRY(inst, s_compat, s_chip, s_type, s_drv, s_min_freq, \
+			    s_max_freq)                                        \
+	COND_CODE_1(DT_NODE_HAS_PROP(DT_INST(inst, s_compat), alternate_for),  \
+		    (DO_MK_SENSOR_ENTRY(DT_INST(inst, s_compat), s_chip,       \
+					s_type, s_drv, s_min_freq,             \
+					s_max_freq)),                          \
+		    ())
 
 #undef CREATE_SENSOR_DATA
 /*
@@ -269,6 +282,26 @@ struct motion_sensor_t motion_sensors[] = {
 #endif
 };
 
+/*
+ * Remap the CREATE_MOTION_SENSOR to call MK_SENSOR_ALT_ENTRY to create a list
+ * of alternate sensors that will be used at runtime.
+ */
+#undef CREATE_MOTION_SENSOR
+#define CREATE_MOTION_SENSOR(s_compat, s_chip, s_type, s_drv, s_min_freq,    \
+			     s_max_freq)                                     \
+	UTIL_LISTIFY(DT_NUM_INST_STATUS_OKAY(s_compat), MK_SENSOR_ALT_ENTRY, \
+		     s_compat, s_chip, s_type, s_drv, s_min_freq, s_max_freq)
+
+/*
+ * The list of alternate motion sensors that may be used at runtime to replace
+ * an entry in the motion_sensors array.
+ */
+__maybe_unused static struct motion_sensor_t motion_sensors_alt[] = {
+#if DT_NODE_EXISTS(SENSOR_ALT_NODE)
+#include "motionsense_driver/sensor_drv_list.inc"
+#endif
+};
+
 #ifdef CONFIG_DYNAMIC_MOTION_SENSOR_COUNT
 unsigned int motion_sensor_count = ARRAY_SIZE(motion_sensors);
 #else