Add SB-TSI temp sensor driver

This adds the driver for the SB-TSI temp sensor.

This is a sensor on the AMD AP SOC (Stoney Ridege FT2) that acts like an
8-pin temp sensor with an I2C interface.

BUG=b:69379715
BRANCH=None
TEST=Build

Change-Id: Iaafe6c7beb3e02e4e341617e8f117c03c0a882a2
Signed-off-by: Alec Thilenius <athilenius@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/833346
Commit-Ready: Alec Thilenius <athilenius@google.com>
Tested-by: Alec Thilenius <athilenius@google.com>
Reviewed-by: Edward Hill <ecgh@chromium.org>

4 files changed, 88 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index e7aca3313d..5497a7a049 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -78,6 +78,7 @@ driver-$(CONFIG_TEMP_SENSOR_BD99992GW)+=temp_sensor/bd99992gw.o
 driver-$(CONFIG_TEMP_SENSOR_EC_ADC)+=temp_sensor/ec_adc.o
 driver-$(CONFIG_TEMP_SENSOR_G781)+=temp_sensor/g78x.o
 driver-$(CONFIG_TEMP_SENSOR_G782)+=temp_sensor/g78x.o
+driver-$(CONFIG_TEMP_SENSOR_SB_TSI)+=temp_sensor/sb_tsi.o
 driver-$(CONFIG_TEMP_SENSOR_TMP006)+=temp_sensor/tmp006.o
 driver-$(CONFIG_TEMP_SENSOR_TMP112)+=temp_sensor/tmp112.o
 driver-$(CONFIG_TEMP_SENSOR_TMP411)+=temp_sensor/tmp411.o
diff --git a/driver/temp_sensor/sb_tsi.c b/driver/temp_sensor/sb_tsi.c
new file mode 100644
index 0000000000..9cf42d983f
--- /dev/null
+++ b/driver/temp_sensor/sb_tsi.c
@@ -0,0 +1,40 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/*
+ * SB-TSI: SB Temperature Sensor Interface.
+ * This is an I2C slave temp sensor on the AMD Stony Ridge FT4 SOC.
+ */
+
+#include "chipset.h"
+#include "common.h"
+#include "console.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "i2c.h"
+#include "sb_tsi.h"
+#include "util.h"
+
+static int raw_read8(const int offset, int *data_ptr)
+{
+	return i2c_read8(I2C_PORT_THERMAL, SB_TSI_I2C_ADDR, offset, data_ptr);
+}
+
+int sb_tsi_get_val(int idx, int *temp_ptr)
+{
+	int ret;
+	/* There is only one temp sensor on the FT4 */
+	if (idx != 0)
+		return EC_ERROR_PARAM1;
+	/* FT4 SB-TSI sensor only powered in S0 */
+	if (!chipset_in_state(CHIPSET_STATE_ON))
+		return EC_ERROR_NOT_POWERED;
+	/* Read the value over I2C */
+	ret = raw_read8(SB_TSI_TEMP_H, temp_ptr);
+	if (ret)
+		return ret;
+	*temp_ptr = C_TO_K(*temp_ptr);
+	return EC_SUCCESS;
+}
diff --git a/driver/temp_sensor/sb_tsi.h b/driver/temp_sensor/sb_tsi.h
new file mode 100644
index 0000000000..3ae11c5dbd
--- /dev/null
+++ b/driver/temp_sensor/sb_tsi.h
@@ -0,0 +1,46 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/*
+ * SB-TSI: SB Temperature Sensor Interface.
+ * This is an I2C slave temp sensor on the AMD Stony Ridge FT4 SOC.
+ */
+
+#ifndef __CROS_EC_SB_TSI_H
+#define __CROS_EC_SB_TSI_H
+
+#define SB_TSI_I2C_ADDR			0x98 /* 7-bit address is 0x4C */
+
+/* G781 register */
+#define SB_TSI_TEMP_H			0x01
+#define SB_TSI_STATUS			0x02
+#define SB_TSI_CONFIG_1			0x03
+#define SB_TSI_UPDATE_RATE		0x04
+#define SB_TSI_HIGH_TEMP_THRESHOLD_H	0x07
+#define SB_TSI_LOW_TEMP_THRESHOLD_H	0x08
+#define SB_TSI_CONFIG_2			0x09
+#define SB_TSI_TEMP_L			0x10
+#define SB_TSI_TEMP_OFFSET_H		0x11
+#define SB_TSI_TEMP_OFFSET_L		0x12
+#define SB_TSI_HIGH_TEMP_THRESHOLD_L	0x13
+#define SB_TSI_LOW_TEMP_THRESHOLD_L	0x14
+#define SB_TSI_TIMEOUT_CONFIG		0x22
+#define SB_TSI_PSTATE_LIMIT_CONFIG	0x2F
+#define SB_TSI_ALERT_THRESHOLD		0x32
+#define SB_TSI_ALERT_CONFIG		0xBF
+#define SB_TSI_MANUFACTURE_ID		0xFE
+#define SB_TSI_REVISION			0xFF
+
+/**
+ * Get the value of a sensor in K.
+ *
+ * @param idx		Index to read. Only 0 is valid for sb_tsi.
+ * @param temp_ptr	Destination for temperature in K.
+ *
+ * @return EC_SUCCESS if successful, non-zero if error.
+ */
+int sb_tsi_get_val(int idx, int *temp_ptr);
+
+#endif  /* __CROS_EC_SB_TSI_H */
diff --git a/include/config.h b/include/config.h
index b242092064..4d047c7186 100644
--- a/include/config.h
+++ b/include/config.h
@@ -2418,6 +2418,7 @@
 #undef CONFIG_TEMP_SENSOR_EC_ADC        /* Thermistors on EC's own ADC */
 #undef CONFIG_TEMP_SENSOR_G781		/* G781 sensor, on I2C bus */
 #undef CONFIG_TEMP_SENSOR_G782		/* G782 sensor, on I2C bus */
+#undef CONFIG_TEMP_SENSOR_SB_TSI	/* SB_TSI sensor, on I2C bus */
 #undef CONFIG_TEMP_SENSOR_TMP006	/* TI TMP006 sensor, on I2C bus */
 #undef CONFIG_TEMP_SENSOR_TMP411	/* TI TMP411 sensor, on I2C bus */
 #undef CONFIG_TEMP_SENSOR_TMP432	/* TI TMP432 sensor, on I2C bus */