COMMON: Add extend function for tmp432 IC

+ create interface to set ALERT# pin as THERM mode
  and set high limit for a selected channel

BUG=None
BRANCH=master
TEST=`make -j runtests`

Change-Id: I7325eb9ddfcaca3ea873e1ee71da74258d7bec72
Signed-off-by: Ryan Zhang <Ryan.Zhang@quantatw.com>
Reviewed-on: https://chromium-review.googlesource.com/344435
Reviewed-by: Shawn N <shawnn@chromium.org>

2 files changed, 90 insertions, 0 deletions

diff --git a/driver/temp_sensor/tmp432.c b/driver/temp_sensor/tmp432.c
index 144a28a9ee..ea49fcb28b 100644
--- a/driver/temp_sensor/tmp432.c
+++ b/driver/temp_sensor/tmp432.c
@@ -117,6 +117,65 @@ static int tmp432_shutdown(uint8_t want_shutdown)
 	return ret;
 }
 
+static int tmp432_set_therm_mode(void)
+{
+	int ret = 0;
+	int data = 0;
+
+	ret = raw_read8(TMP432_CONFIGURATION1_R, &data);
+	if (ret)
+		return EC_ERROR_UNKNOWN;
+
+	data |= TMP432_CONFIG1_MODE;
+	ret = raw_write8(TMP432_CONFIGURATION1_W, data);
+	if (ret)
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
+int tmp432_set_therm_limit(int channel, int limit_c, int hysteresis)
+{
+	int ret = 0;
+	int reg = 0;
+
+	if (channel >= TMP432_CHANNEL_COUNT)
+		return EC_ERROR_INVAL;
+
+	if (hysteresis > TMP432_HYSTERESIS_HIGH_LIMIT ||
+		hysteresis < TMP432_HYSTERESIS_LOW_LIMIT)
+		return EC_ERROR_INVAL;
+
+	/* hysteresis must be less than high limit */
+	if (hysteresis > limit_c)
+		return EC_ERROR_INVAL;
+
+	if (tmp432_set_therm_mode() != EC_SUCCESS)
+		return EC_ERROR_UNKNOWN;
+
+	switch (channel) {
+	case TMP432_CHANNEL_LOCAL:
+		reg = TMP432_LOCAL_HIGH_LIMIT_W;
+		break;
+	case TMP432_CHANNEL_REMOTE1:
+		reg = TMP432_REMOTE1_HIGH_LIMIT_W;
+		break;
+	case TMP432_CHANNEL_REMOTE2:
+		reg = TMP432_REMOTE2_HIGH_LIMIT_W;
+		break;
+	}
+
+	ret = raw_write8(reg, limit_c);
+	if (ret)
+		return EC_ERROR_UNKNOWN;
+
+	ret = raw_write8(TMP432_THERM_HYSTERESIS, hysteresis);
+	if (ret)
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
 static void temp_sensor_poll(void)
 {
 	int temp_c;
diff --git a/driver/temp_sensor/tmp432.h b/driver/temp_sensor/tmp432.h
index 2aae435dd5..ea6f3286c6 100644
--- a/driver/temp_sensor/tmp432.h
+++ b/driver/temp_sensor/tmp432.h
@@ -67,6 +67,7 @@
 
 /* Config register bits */
 #define TMP432_CONFIG1_TEMP_RANGE	(1 << 2)
+/* TMP432_CONFIG1_MODE bit is use to enable THERM mode */
 #define TMP432_CONFIG1_MODE		(1 << 5)
 #define TMP432_CONFIG1_RUN_L		(1 << 6)
 #define TMP432_CONFIG1_ALERT_MASK_L	(1 << 7)
@@ -82,12 +83,24 @@
 #define TMP432_STATUS_TEMP_HIGH_ALARM	(1 << 4)
 #define TMP432_STATUS_BUSY		(1 << 7)
 
+/* Limintaions */
+#define TMP432_HYSTERESIS_HIGH_LIMIT	255
+#define TMP432_HYSTERESIS_LOW_LIMIT	0
+
 enum tmp432_power_state {
 	TMP432_POWER_OFF = 0,
 	TMP432_POWER_ON,
 	TMP432_POWER_COUNT
 };
 
+enum tmp432_channel_id {
+	TMP432_CHANNEL_LOCAL,
+	TMP432_CHANNEL_REMOTE1,
+	TMP432_CHANNEL_REMOTE2,
+
+	TMP432_CHANNEL_COUNT
+};
+
 /**
  * Get the last polled value of a sensor.
  *
@@ -108,4 +121,22 @@ int tmp432_get_val(int idx, int *temp_ptr);
  * @return EC_SUCCESS if successful, non-zero if error.
  */
 int tmp432_set_power(enum tmp432_power_state power_on);
+
+/*
+ * Set TMP432 ALERT#/THERM2# pin to THERM mode, and give a limit
+ * for a specific channel.
+ *
+ * @param channel	specific a channel
+ *
+ * @param limit_c	High limit temperature, default: 85C
+ *
+ * @param hysteresis	Hysteresis temperature, default: 10C
+ *			All channels share the same hysteresis
+ *
+ * In THERM mode, ALERT# pin will trigger(Low) by itself when any
+ * channel's temperature is greater( >= )than channel's limit_c,
+ * and release(High) by itself when channel's temperature is lower
+ * than (limit_c - hysteresis)
+ */
+int tmp432_set_therm_limit(int channel, int limit_c, int hysteresis);
 #endif /* __CROS_EC_TMP432_H */