tmp112: Support reading TMP112 in millikelvin

TMP112 supports .0625 degrees of resolution. Retain this resolution and
support reading the temp in degrees millikelvin.

BUG=b:176994331
TEST=Build and run on guybrush
BRANCH=None

Change-Id: I2802016b1edb08678953238e7f01acdd320c37cf
Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3001391
Commit-Queue: Diana Z <dzigterman@chromium.org>
Reviewed-by: Diana Z <dzigterman@chromium.org>

8 files changed, 41 insertions, 18 deletions

diff --git a/baseboard/guybrush/baseboard.c b/baseboard/guybrush/baseboard.c
index 675350a022..5768326c44 100644
--- a/baseboard/guybrush/baseboard.c
+++ b/baseboard/guybrush/baseboard.c
@@ -227,7 +227,7 @@ const struct temp_sensor_t temp_sensors[] = {
 	[TEMP_SENSOR_AMBIENT] = {
 		.name = "Ambient",
 		.type = TEMP_SENSOR_TYPE_BOARD,
-		.read = tmp112_get_val,
+		.read = tmp112_get_val_k,
 		.idx = TMP112_AMB,
 	},
 };
diff --git a/board/dewatt/board.c b/board/dewatt/board.c
index 54cc3a61a5..b773499326 100644
--- a/board/dewatt/board.c
+++ b/board/dewatt/board.c
@@ -370,5 +370,5 @@ int board_get_soc_temp(int idx, int *temp_k)
 	if (board_version == 1)
 		return get_temp_3v3_30k9_47k_4050b(ADC_TEMP_SENSOR_SOC, temp_k);
 
-	return tmp112_get_val(idx, temp_k);
+	return tmp112_get_val_k(idx, temp_k);
 }
diff --git a/board/guybrush/board.c b/board/guybrush/board.c
index e6e7256eec..fd260a0690 100644
--- a/board/guybrush/board.c
+++ b/board/guybrush/board.c
@@ -370,5 +370,5 @@ int board_get_soc_temp(int idx, int *temp_k)
 	if (board_version == 1)
 		return get_temp_3v3_30k9_47k_4050b(ADC_TEMP_SENSOR_SOC, temp_k);
 
-	return tmp112_get_val(idx, temp_k);
+	return tmp112_get_val_k(idx, temp_k);
 }
diff --git a/board/nipperkin/board.c b/board/nipperkin/board.c
index 3a76bb3175..ca2218ea84 100644
--- a/board/nipperkin/board.c
+++ b/board/nipperkin/board.c
@@ -150,5 +150,5 @@ int board_get_soc_temp(int idx, int *temp_k)
 	if (board_version == 1)
 		return get_temp_3v3_30k9_47k_4050b(ADC_TEMP_SENSOR_SOC, temp_k);
 
-	return tmp112_get_val(idx, temp_k);
+	return tmp112_get_val_k(idx, temp_k);
 }
diff --git a/board/npcx9_evb/board.c b/board/npcx9_evb/board.c
index 876ca7bd10..a104a409b0 100644
--- a/board/npcx9_evb/board.c
+++ b/board/npcx9_evb/board.c
@@ -90,7 +90,7 @@ BUILD_ASSERT(ARRAY_SIZE(tmp112_sensors) == TMP112_COUNT);
 /******************************************************************************/
 /* Temperature sensor. */
 const struct temp_sensor_t temp_sensors[] = {
-	{ "System", TEMP_SENSOR_TYPE_BOARD, tmp112_get_val, TMP112_0 },
+	{ "System", TEMP_SENSOR_TYPE_BOARD, tmp112_get_val_k, TMP112_0 },
 };
 BUILD_ASSERT(ARRAY_SIZE(temp_sensors) == TEMP_SENSOR_COUNT);
 
diff --git a/common/build.mk b/common/build.mk
index 7c505c066f..2ba81f6006 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -28,6 +28,7 @@ common-$(CONFIG_ACCEL_LIS2DH)+=math_util.o
 common-$(CONFIG_ACCEL_LIS2DS)+=math_util.o
 common-$(CONFIG_ACCEL_KXCJ9)+=math_util.o
 common-$(CONFIG_ACCEL_KX022)+=math_util.o
+common-$(CONFIG_TEMP_SENSOR_TMP112)+=math_util.o
 ifneq ($(CORE),cortex-m)
 common-$(CONFIG_AES)+=aes.o
 endif
diff --git a/driver/temp_sensor/tmp112.c b/driver/temp_sensor/tmp112.c
index 064bc70301..4da5c4e0e8 100644
--- a/driver/temp_sensor/tmp112.c
+++ b/driver/temp_sensor/tmp112.c
@@ -10,6 +10,7 @@
 #include "tmp112.h"
 #include "i2c.h"
 #include "hooks.h"
+#include "math_util.h"
 #include "util.h"
 
 #define TMP112_RESOLUTION 12
@@ -18,7 +19,7 @@
 
 #define CPRINTS(format, args...) cprints(CC_THERMAL, format, ## args)
 
-static int temp_val_local[TMP112_COUNT];
+static int temp_mk_local[TMP112_COUNT];
 
 static int raw_read16(int sensor, const int offset, int *data_ptr)
 {
@@ -48,7 +49,7 @@ static int raw_write16(int sensor, const int offset, int data)
 			   offset, data);
 }
 
-static int get_temp(int sensor, int *temp_ptr)
+static int get_reg_temp(int sensor, int *temp_ptr)
 {
 	int rv;
 	int temp_raw = 0;
@@ -61,32 +62,41 @@ static int get_temp(int sensor, int *temp_ptr)
 	return EC_SUCCESS;
 }
 
-static inline int tmp112_reg_to_c(int16_t reg)
+static inline int tmp112_reg_to_mk(int16_t reg)
 {
-	int tmp;
+	int temp_mc;
 
-	tmp = (((reg >> TMP112_SHIFT1) * 1000 ) >> TMP112_SHIFT2);
+	temp_mc = (((reg >> TMP112_SHIFT1) * 1000) >> TMP112_SHIFT2);
 
-	return tmp / 1000;
+	return MILLI_CELSIUS_TO_MILLI_KELVIN(temp_mc);
 }
 
-int tmp112_get_val(int idx, int *temp_ptr)
+int tmp112_get_val_k(int idx, int *temp_k_ptr)
 {
 	if (idx >= TMP112_COUNT)
 		return EC_ERROR_INVAL;
 
-	*temp_ptr = temp_val_local[idx];
+	*temp_k_ptr = MILLI_KELVIN_TO_KELVIN(temp_mk_local[idx]);
+	return EC_SUCCESS;
+}
+
+int tmp112_get_val_mk(int idx, int *temp_mk_ptr)
+{
+	if (idx >= TMP112_COUNT)
+		return EC_ERROR_INVAL;
+
+	*temp_mk_ptr = temp_mk_local[idx];
 	return EC_SUCCESS;
 }
 
 static void tmp112_poll(void)
 {
 	int s;
-	int temp_c = 0;
+	int temp_reg = 0;
 
 	for (s = 0; s < TMP112_COUNT; s++) {
-		if (get_temp(s, &temp_c) == EC_SUCCESS)
-			temp_val_local[s] = C_TO_K(tmp112_reg_to_c(temp_c));
+		if (get_reg_temp(s, &temp_reg) == EC_SUCCESS)
+			temp_mk_local[s] = tmp112_reg_to_mk(temp_reg);
 	}
 }
 DECLARE_HOOK(HOOK_SECOND, tmp112_poll, HOOK_PRIO_TEMP_SENSOR);
diff --git a/driver/temp_sensor/tmp112.h b/driver/temp_sensor/tmp112.h
index fce7edc15b..d1b97b138c 100644
--- a/driver/temp_sensor/tmp112.h
+++ b/driver/temp_sensor/tmp112.h
@@ -38,11 +38,23 @@ extern const struct tmp112_sensor_t tmp112_sensors[];
  * @param idx		Index to read, from board's enum tmp112_sensor
  *			definition
  *
- * @param temp_ptr	Destination for temperature in K.
+ * @param temp_k_ptr	Destination for temperature in K.
  *
  * @return EC_SUCCESS if successful, non-zero if error.
  */
-int tmp112_get_val(int idx, int *temp_ptr);
+int tmp112_get_val_k(int idx, int *temp_k_ptr);
+
+/**
+ * Get the last polled value of a sensor.
+ *
+ * @param idx		Index to read, from board's enum tmp112_sensor
+ *			definition
+ *
+ * @param temp_mk_ptr	Destination for temperature in mK.
+ *
+ * @return EC_SUCCESS if successful, non-zero if error.
+ */
+int tmp112_get_val_mk(int idx, int *temp_mk_ptr);
 
 /**
  * Init the sensors.  Note, this will run automatically on HOOK_INIT, but is