phaser: fix lis2de resolution and sensor value output

lis2de only support 8-bit resolution. This is what is different
from lis2dh. This patch add two defines (CONFIG_ACCEL_LIS2DH and
CONFIG_ACCEL_LIS2DE) to defferientiate them.
For calculate_lid_angle() reliable calculation, code asks for
16 bits sensor value output, this patch fix that as well.

Signed-off-by: Paul Ma <magf@bitland.corp-partner.google.com>

BRANCH=none
BUG=b:110604678
TEST=boot phaser360 board, use 'accelinfo on' to watch lid output
     and angle output, lid axis value should be 16 bit range and
     angle is correct.

Change-Id: If77954ecf477736b9168b3a3b6805396a3201a57
Reviewed-on: https://chromium-review.googlesource.com/1111775
Commit-Ready: Paul Ma <magf@bitland.corp-partner.google.com>
Tested-by: Paul Ma <magf@bitland.corp-partner.google.com>
Reviewed-by: Jett Rink <jettrink@chromium.org>

5 files changed, 34 insertions, 7 deletions

diff --git a/board/phaser/board.h b/board/phaser/board.h
index 4c5a41059a..c8c866b703 100644
--- a/board/phaser/board.h
+++ b/board/phaser/board.h
@@ -30,7 +30,7 @@
 #define CONFIG_CMD_ACCEL_INFO
 
 /* Sensors */
-#define CONFIG_ACCEL_LIS2DH             /* Lid accel */
+#define CONFIG_ACCEL_LIS2DE             /* Lid accel */
 #define CONFIG_ACCELGYRO_LSM6DSM        /* Base accel */
 /* Sensors without hardware FIFO are in forced mode */
 #define CONFIG_ACCEL_FORCE_MODE_MASK (1 << LID_ACCEL)
diff --git a/driver/accel_lis2dh.h b/driver/accel_lis2dh.h
index 0421f79503..fe8d17641e 100644
--- a/driver/accel_lis2dh.h
+++ b/driver/accel_lis2dh.h
@@ -102,11 +102,15 @@ enum lis2dh_odr {
 #define LIS2DH_FS_TO_REG(_fs) (__fls(_fs) - 1)
 
 /* Sensor resolution in number of bits
- * This sensor has variable precision (8/10/12 bits) depending Power Mode
- * selected
- * TODO: Only Normal Power mode supported (10 bits)
+ * lis2dh has variable precision (8/10/12 bits) depending Power Mode
+ * selected, here Only Normal Power mode supported (10 bits).
+ * But for lis2de, it has only one 8bit resolution.
  */
+#ifdef CONFIG_ACCEL_LIS2DE
+#define LIS2DH_RESOLUTION       8
+#elif defined(CONFIG_ACCEL_LIS2DH)
 #define LIS2DH_RESOLUTION      	10
+#endif
 
 extern const struct accelgyro_drv lis2dh_drv;
 
diff --git a/driver/build.mk b/driver/build.mk
index 68b14f836e..6d0990bcec 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -14,7 +14,7 @@ driver-$(CONFIG_ACCELGYRO_LSM6DS0)+=accelgyro_lsm6ds0.o
 driver-$(CONFIG_ACCELGYRO_BMI160)+=accelgyro_bmi160.o
 driver-$(CONFIG_MAG_BMI160_BMM150)+=mag_bmm150.o
 driver-$(CONFIG_ACCELGYRO_LSM6DSM)+=accelgyro_lsm6dsm.o stm_mems_common.o
-driver-$(CONFIG_ACCEL_LIS2DH)+=accel_lis2dh.o stm_mems_common.o
+driver-$(CONFIG_ACCEL_LIS2D_COMMON)+=accel_lis2dh.o stm_mems_common.o
 driver-$(CONFIG_SYNC)+=sync.o
 
 # BC1.2 Charger Detection Devices
diff --git a/driver/stm_mems_common.c b/driver/stm_mems_common.c
index c7b84b5b98..427fc8091f 100644
--- a/driver/stm_mems_common.c
+++ b/driver/stm_mems_common.c
@@ -134,10 +134,13 @@ void st_normalize(const struct motion_sensor_t *s, vector_3_t v, uint8_t *data)
 {
 	int i, range;
 	struct stprivate_data *drvdata = s->drv_data;
+	/* data is left-aligned and the bottom bits need to be
+	 * cleared because they may contain trash data.
+	 */
+	uint16_t mask = ~((1 << (16 - drvdata->resol)) - 1);
 
 	for (i = X; i <= Z; i++) {
-		v[i] = (int16_t)((data[i * 2 + 1] << 8) |
-				data[i * 2]) >> (16 - drvdata->resol);
+		v[i] = ((data[i * 2 + 1] << 8) | data[i * 2]) & mask;
 	}
 
 	rotate(v, *s->rot_standard_ref, v);
diff --git a/include/config.h b/include/config.h
index 42cbe178ec..ad23544891 100644
--- a/include/config.h
+++ b/include/config.h
@@ -64,7 +64,17 @@
 #undef CONFIG_ACCEL_BMA255
 #undef CONFIG_ACCEL_KXCJ9
 #undef CONFIG_ACCEL_KX022
+/*
+ * lis2dh and lis2de have the same register interface but different
+ * supported resolution. In normal mode, lis2dh works in 10-bit resolution,
+ * but lis2de only supports 8bit resolution.
+ * define CONFIG_ACCEL_LIS2DH if using lis2dh chip on the board and define
+ * CONFIG_ACCEL_LIS2DE if using lis2de chip. CONFIG_ACCEL_LIS2D_COMMON get
+ * automatically defined if either of them get defined.
+ */
 #undef CONFIG_ACCEL_LIS2DH
+#undef CONFIG_ACCEL_LIS2DE
+#undef CONFIG_ACCEL_LIS2D_COMMON
 #undef CONFIG_ACCELGYRO_LSM6DS0
 #undef CONFIG_ACCELGYRO_BMI160
 #undef CONFIG_ACCELGYRO_LSM6DSM
@@ -3766,6 +3776,15 @@
 #endif
 
 /*****************************************************************************/
+
+/*
+ * Automatically define CONFIG_ACCEL_LIS2D_COMMON if either child option is
+ * defined.
+ */
+#if defined(CONFIG_ACCEL_LIS2DH) || defined(CONFIG_ACCEL_LIS2DE)
+#define CONFIG_ACCEL_LIS2D_COMMON
+#endif
+
 /*
  * Apply test config overrides last, since tests need to override some of the
  * config flags in non-standard ways to mock only parts of the system.
@@ -3794,3 +3813,4 @@
 #define CONFIG_BMI160_SEC_I2C
 #endif
 #endif  /* __CROS_EC_CONFIG_H */
+