fwk: add temperature_filter file for virtual temp

Signed-off-by: LeoCX_Tsai <LeoCX_Tsai@compal.com>

Author: kiram9

baseboard/fwk/build.mk

@@ -13,3 +13,4 @@ baseboard-$(CONFIG_SYSTEMSERIAL_DEBUG) += system_serial.o
 baseboard-$(CONFIG_8042_AUX) += ps2mouse.o
 baseboard-$(HAS_TASK_HOSTCMD) += baseboard_host_commands.o
 baseboard-$(CONFIG_CHARGE_MANAGER) += battery_extender.o
+baseboard-$(CONFIG_FAN_VIRTUAL_TEMP) += temperature_filter.o

baseboard/fwk/temperature_filter.c

@@ -0,0 +1,37 @@
+#include <string.h>
+#include "console.h"
+#include "i2c_hid.h"
+#include "hooks.h"
+#include "host_command.h"
+#include "util.h"
+#include "math_util.h"
+#include "temperature_filter.h"
+
+
+
+void thermal_filter_reset(struct biquad *filter)
+{
+	memset(&filter->state, 30 << IN_SCALE, sizeof(filter->state));
+}
+
+int thermal_filter_update(struct biquad *filter, int value)
+{
+	int out_scaled =
+		filter->coeff[0] * (value << IN_SCALE) +
+		filter->coeff[1] * filter->state[0] +
+		filter->coeff[2] * filter->state[1] -
+		filter->coeff[4] * filter->state[2] -
+		filter->coeff[5] * filter->state[3];
+	int out = out_scaled >> Q_SCALE;
+	/* update delay line */
+	filter->state[1] = filter->state[0];
+	filter->state[3] = filter->state[2];
+	filter->state[0] = value << IN_SCALE;
+	filter->state[2] = out;
+	return out >> IN_SCALE;
+}
+
+int thermal_filter_get(struct biquad *filter)
+{
+	return filter->state[2] >> IN_SCALE;
+}

baseboard/fwk/temperature_filter.h

@@ -0,0 +1,29 @@
+/* Copyright 2022 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Low pass filter for on die temperature
+ */
+#ifndef __CROS_EC_TEMPERATURE_FILTER_H
+#define __CROS_EC_TEMPERATURE_FILTER_H
+
+#include "util.h"
+#include "math_util.h"
+
+#define Q_SCALE 14
+/* scale input up to improve filter performance */
+#define IN_SCALE 7
+
+struct biquad {
+	/* State values x[n-1], x[n-2], y[n-1], y[n-2] */
+	int32_t state[4];
+	const int32_t *coeff;
+};
+
+void thermal_filter_reset(struct biquad *filter);
+
+int thermal_filter_update(struct biquad *filter, int value);
+
+int thermal_filter_get(struct biquad *filter);
+
+#endif /* __CROS_EC_TEMPERATURE_FILTER_H */

board/hx30/board.h

@@ -457,6 +457,13 @@
 
 #define CONFIG_WP_ACTIVE_HIGH
 
+/*
+ * Enable Virtual temp for better fan running
+ * also smooth fan up/down rate.
+ */
+#define CONFIG_FAN_VIRTUAL_TEMP
+
+
 /* LED signals */
 /*
 #define GPIO_BAT_LED_RED    GPIO_BATT_LOW_LED_L

common/thermal.c

@@ -60,7 +60,7 @@ static void thermal_control(void)
 	int temp_fan_configured;
 
 #ifdef CONFIG_CUSTOM_FAN_CONTROL
-	int temp[TEMP_SENSOR_COUNT];
+	int temp[TEMP_SENSOR_COUNT] = {0};
 #endif
 
 	/* Get ready to count things */
@@ -87,6 +87,11 @@ static void thermal_control(void)
 		else
 			num_sensors_read++;
 
+#if defined(CONFIG_FANS) && defined(CONFIG_CUSTOM_FAN_CONTROL)
+		/* Store all sensors value */
+		temp[i] = K_TO_C(t);
+#endif
+
 		/* check all the limits */
 		for (j = 0; j < EC_TEMP_THRESH_COUNT; j++) {
 			int limit = thermal_params[i].temp_host[j];