Initialize temperature reading buffer to sane values

This is to prevent temperature value being read before the first time we
poll sensors causes unexpected error.

BUG=chrome-os-partner:12614
TEST="sysjump RW" and then "temps" immediately. Check all temperature
     readings are near 300 K.

Original-Change-Id: I5c84d9696b4876fdfcf14c3a416cbc09c040d4ee
Signed-off-by: Vic Yang <victoryang@chromium.org>
(cherry picked from commit 208e08322d4ce9ed08901a4c43ac9db40cfe392e)

Change-Id: Ie12ed3bf6733fb45aaafc77de80e5a0adf37e42c
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/30141
(cherry picked from commit c981712156eff1ee68bf375f95cca05c5885af2c)

4 files changed, 57 insertions, 5 deletions

diff --git a/chip/lm4/chip_temp_sensor.c b/chip/lm4/chip_temp_sensor.c
index 657f582275..fb9084e82e 100644
--- a/chip/lm4/chip_temp_sensor.c
+++ b/chip/lm4/chip_temp_sensor.c
@@ -7,6 +7,7 @@
 
 #include "adc.h"
 #include "board.h"
+#include "hooks.h"
 #include "temp_sensor.h"
 
 static int last_val;
@@ -22,3 +23,11 @@ int chip_temp_sensor_get_val(int idx)
 {
 	return last_val;
 }
+
+static int chip_temp_sensor_init(void)
+{
+	/* Initialize temperature reading to a sane value. */
+	last_val = 300; /* 27 C */
+	return EC_SUCCESS;
+}
+DECLARE_HOOK(HOOK_INIT, chip_temp_sensor_init, HOOK_PRIO_DEFAULT);
diff --git a/chip/lm4/peci.c b/chip/lm4/peci.c
index 1ea876fbcd..4091ee8640 100644
--- a/chip/lm4/peci.c
+++ b/chip/lm4/peci.c
@@ -139,6 +139,7 @@ DECLARE_CONSOLE_COMMAND(pecitemp, command_peci_temp,
 static int peci_init(void)
 {
 	volatile uint32_t scratch  __attribute__((unused));
+	int i;
 
 	/* Enable the PECI module and delay a few clocks */
 	LM4_SYSTEM_RCGCPECI = 1;
@@ -150,6 +151,10 @@ static int peci_init(void)
 	/* Set initial clock frequency */
 	peci_freq_changed();
 
+	/* Initialize temperature reading buffer to a sane value. */
+	for (i = 0; i < TEMP_AVG_LENGTH; ++i)
+		temp_vals[i] = 300; /* 27 C */
+
 	return EC_SUCCESS;
 }
 DECLARE_HOOK(HOOK_INIT, peci_init, HOOK_PRIO_DEFAULT);
diff --git a/common/temp_sensor.c b/common/temp_sensor.c
index 9f653612f0..cdad3ebd1f 100644
--- a/common/temp_sensor.c
+++ b/common/temp_sensor.c
@@ -106,12 +106,30 @@ static void update_mapped_memory(void)
 void temp_sensor_task(void)
 {
 	int i;
+	uint8_t *base, *base_b;
+
+	/*
+	 * Initialize memory-mapped data. We initialize valid sensors to 23 C
+	 * so that if a temperature value is read before we actually poll the
+	 * sensors, we don't end up with an insane value.
+	 */
+	base = host_get_memmap(EC_MEMMAP_TEMP_SENSOR);
+	base_b = host_get_memmap(EC_MEMMAP_TEMP_SENSOR_B);
+	for (i = 0; i < TEMP_SENSOR_COUNT; ++i) {
+		if (i < EC_TEMP_SENSOR_ENTRIES)
+			base[i] = 0x60; /* 23 C */
+		else
+			base_b[i - EC_TEMP_SENSOR_ENTRIES] = 0x60; /* 23 C */
+	}
 
-	/* Initialize memory-mapped data */
-	memset(host_get_memmap(EC_MEMMAP_TEMP_SENSOR),
-	       EC_TEMP_SENSOR_NOT_PRESENT, EC_TEMP_SENSOR_ENTRIES);
-	memset(host_get_memmap(EC_MEMMAP_TEMP_SENSOR_B),
-	       EC_TEMP_SENSOR_NOT_PRESENT, EC_TEMP_SENSOR_B_ENTRIES);
+	/* Set the rest of memory region to SENSOR_NOT_PRESENT */
+	for (; i < EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES; ++i) {
+		if (i < EC_TEMP_SENSOR_ENTRIES)
+			base[i] = EC_TEMP_SENSOR_NOT_PRESENT;
+		else
+			base_b[i - EC_TEMP_SENSOR_ENTRIES] =
+				EC_TEMP_SENSOR_NOT_PRESENT;
+	}
 
 	/* Temp sensor data is present, with B range supported. */
 	*host_get_memmap(EC_MEMMAP_THERMAL_VERSION) = 2;
diff --git a/common/tmp006.c b/common/tmp006.c
index 819ecda7c2..a0c6e3e455 100644
--- a/common/tmp006.c
+++ b/common/tmp006.c
@@ -10,6 +10,7 @@
 #include "console.h"
 #include "fpu.h"
 #include "gpio.h"
+#include "hooks.h"
 #include "i2c.h"
 #include "math.h"
 #include "task.h"
@@ -273,6 +274,25 @@ int tmp006_poll(void)
 	return rv1;
 }
 
+static int tmp006_init(void)
+{
+	int i, j;
+
+	/*
+	 * Set temperature value to 27 C and we will update it later when
+	 * polled by temperature sensor module.
+	 */
+	for (i = 0; i < TMP006_COUNT; ++i) {
+		for (j = 0; j < 4; ++j)
+			tmp006_data[i].t[j] = 30000; /* 27 C */
+		tmp006_data[i].tidx = 0;
+		/* TODO(victoryang): Default value for V? */
+	}
+
+	return EC_SUCCESS;
+}
+DECLARE_HOOK(HOOK_INIT, tmp006_init, HOOK_PRIO_DEFAULT);
+
 
 /*****************************************************************************/
 /* Console commands */