eldrid: add custom fan control

This is an initial version. Also disable fan when enter S0ix.

BUG=b:167931578
BRANCH=none
TEST=make -j BOARD=volteer
TEST=make buildall
TEST=verify by thermal team

Change-Id: I146caf056486709763d2793e9c43b6e713bf87e0
Signed-off-by: Scott Chao <scott_chao@wistron.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2393408
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>

3 files changed, 163 insertions, 0 deletions

diff --git a/board/eldrid/board.h b/board/eldrid/board.h
index 8e59d5e0c6..0e8d754182 100644
--- a/board/eldrid/board.h
+++ b/board/eldrid/board.h
@@ -114,6 +114,7 @@
 /* Volume Button feature */
 
 /* Fan features */
+#define CONFIG_CUSTOM_FAN_CONTROL
 
 /* charger defines */
 #define CONFIG_CHARGER_SENSE_RESISTOR		10
diff --git a/board/eldrid/build.mk b/board/eldrid/build.mk
index b78172d3cf..8a5f8f68cd 100644
--- a/board/eldrid/build.mk
+++ b/board/eldrid/build.mk
@@ -15,3 +15,4 @@ board-y=board.o
 board-y+=battery.o
 board-y+=led.o
 board-y+=sensors.o
+board-y+=thermal.o
diff --git a/board/eldrid/thermal.c b/board/eldrid/thermal.c
new file mode 100644
index 0000000000..ce36ce3860
--- /dev/null
+++ b/board/eldrid/thermal.c
@@ -0,0 +1,161 @@
+/* Copyright 2020 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.
+ */
+
+#include "chipset.h"
+#include "common.h"
+#include "console.h"
+#include "fan.h"
+#include "hooks.h"
+#include "host_command.h"
+#include "temp_sensor.h"
+#include "thermal.h"
+#include "util.h"
+
+/* Console output macros */
+#define CPUTS(outstr) cputs(CC_THERMAL, outstr)
+#define CPRINTS(format, args...) cprints(CC_THERMAL, format, ## args)
+
+struct fan_step {
+	/*
+	 * Sensor 1~4 trigger point, set -1 if we're not using this
+	 * sensor to determine fan speed.
+	 */
+	int8_t on[TEMP_SENSOR_COUNT];
+
+	/*
+	 * Sensor 1~4 trigger point, set -1 if we're not using this
+	 * sensor to determine fan speed.
+	 */
+	int8_t off[TEMP_SENSOR_COUNT];
+
+	/* Fan rpm */
+	uint16_t rpm[FAN_CH_COUNT];
+};
+
+/*
+ * TODO(b/167931578) Only monitor sensor3 for now.
+ * Will add more sensors support if needed.
+ */
+static const struct fan_step fan_table[] = {
+	{
+		/* level 0 */
+		.on = {-1, -1, 36, -1},
+		.off = {-1, -1, 0, -1},
+		.rpm = {0},
+	},
+	{
+		/* level 1 */
+		.on = {-1, -1, 38, -1},
+		.off = {-1, -1, 36, -1},
+		.rpm = {2000},
+	},
+	{
+		/* level 2 */
+		.on = {-1, -1, 41, -1},
+		.off = {-1, -1, 39, -1},
+		.rpm = {2600},
+	},
+	{
+		/* level 3 */
+		.on = {-1, -1, 44, -1},
+		.off = {-1, -1, 42, -1},
+		.rpm = {3000},
+	},
+	{
+		/* level 4 */
+		.on = {-1, -1, 46, -1},
+		.off = {-1, -1, 44, -1},
+		.rpm = {3300},
+	},
+	{
+		/* level 5 */
+		.on = {-1, -1, 49, -1},
+		.off = {-1, -1, 47, -1},
+		.rpm = {3600},
+	},
+	{
+		/* level 6 */
+		.on = {-1, -1, 51, -1},
+		.off = {-1, -1, 49, -1},
+		.rpm = {4200},
+	},
+	{
+		/* level 7 */
+		.on = {-1, -1, 55, -1},
+		.off = {-1, -1, 52, -1},
+		.rpm = {4700},
+	},
+};
+
+int fan_table_to_rpm(int fan, int *temp)
+{
+	/* current fan level */
+	static int current_level;
+	/* previous sensor temperature */
+	static int prev_temp[TEMP_SENSOR_COUNT];
+	const int num_fan_levels = ARRAY_SIZE(fan_table);
+	int i;
+	int new_rpm = 0;
+
+	/*
+	 * Compare the current and previous temperature, we have
+	 * the three paths :
+	 *  1. decreasing path. (check the release point)
+	 *  2. increasing path. (check the trigger point)
+	 *  3. invariant path. (return the current RPM)
+	 */
+
+	CPRINTS("temp: %d, prev_temp: %d", temp[TEMP_SENSOR_3_DDR_SOC],
+		prev_temp[TEMP_SENSOR_3_DDR_SOC]);
+	if (temp[TEMP_SENSOR_3_DDR_SOC] < prev_temp[TEMP_SENSOR_3_DDR_SOC]) {
+		for (i = current_level; i > 0; i--) {
+			if (temp[TEMP_SENSOR_3_DDR_SOC] <
+				fan_table[i].off[TEMP_SENSOR_3_DDR_SOC])
+				current_level = i - 1;
+			else
+				break;
+		}
+	} else if (temp[TEMP_SENSOR_3_DDR_SOC] >
+		prev_temp[TEMP_SENSOR_3_DDR_SOC]) {
+		for (i = current_level; i < num_fan_levels; i++) {
+			if (temp[TEMP_SENSOR_3_DDR_SOC] >
+				fan_table[i].on[TEMP_SENSOR_3_DDR_SOC])
+				current_level = i + 1;
+			else
+				break;
+		}
+	}
+
+	if (current_level < 0)
+		current_level = 0;
+
+	for (i = 0; i < TEMP_SENSOR_COUNT; ++i)
+		prev_temp[i] = temp[i];
+
+	CPRINTS("current_level: %d", current_level);
+
+	switch (fan) {
+	case FAN_CH_0:
+		new_rpm = fan_table[current_level].rpm[FAN_CH_0];
+		break;
+	default:
+		break;
+	}
+
+	return new_rpm;
+}
+
+void board_override_fan_control(int fan, int *temp)
+{
+	if (chipset_in_state(CHIPSET_STATE_ON)) {
+		fan_set_rpm_mode(FAN_CH(fan), 1);
+		fan_set_rpm_target(FAN_CH(fan),
+			fan_table_to_rpm(fan, temp));
+	} else if (chipset_in_state(CHIPSET_STATE_ANY_SUSPEND)) {
+		/* Stop fan when enter S0ix */
+		fan_set_rpm_mode(FAN_CH(fan), 1);
+		fan_set_rpm_target(FAN_CH(fan), 0);
+	}
+}