1 files changed, 99 insertions, 0 deletions
diff --git a/zephyr/program/skyrim/markarth/src/thermal.c b/zephyr/program/skyrim/markarth/src/thermal.c
new file mode 100644
index 0000000000..dab74883be
--- /dev/null
+++ b/zephyr/program/skyrim/markarth/src/thermal.c
@@ -0,0 +1,99 @@
+/* Copyright 2023 The ChromiumOS Authors
+ * 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 "tablet_mode.h"
+#include "temp_sensor/temp_sensor.h"
+#include "thermal.h"
+#include "util.h"
+
+#define TEMP_CPU TEMP_SENSOR_ID(DT_NODELABEL(temp_sensor_cpu))
+
+struct fan_step {
+	/*
+	 * Sensor 0~4 trigger point, set -1 if we're not using this
+	 * sensor to determine fan speed.
+	 */
+	int on[TEMP_SENSOR_COUNT];
+	/*
+	 * Sensor 0~4 release point, set -1 if we're not using this
+	 * sensor to determine fan speed.
+	 */
+	int off[TEMP_SENSOR_COUNT];
+	/* Fan rpm */
+	uint16_t rpm[FAN_CH_COUNT];
+};
+
+#define FAN_TABLE_ENTRY(nd)                     \
+	{                                       \
+		.on = DT_PROP(nd, temp_on),     \
+		.off = DT_PROP(nd, temp_off),   \
+		.rpm = DT_PROP(nd, rpm_target), \
+	},
+
+static const struct fan_step fan_table[] = { DT_FOREACH_CHILD(
+	DT_NODELABEL(fan_steps), FAN_TABLE_ENTRY) };
+
+static const struct fan_step *fan_step_table = fan_table;
+#define NUM_FAN_LEVELS ARRAY_SIZE(fan_table)
+
+int fan_table_to_rpm(int fan, int *temp)
+{
+	/* current fan level */
+	static int current_level;
+	/* previous sensor temperature */
+	static int prev_tmp[TEMP_SENSOR_COUNT];
+	int i;
+
+	/*
+	 * 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)
+	 */
+
+	if (temp[TEMP_CPU] < prev_tmp[TEMP_CPU]) {
+		for (i = current_level; i > 0; i--) {
+			if (temp[TEMP_CPU] <= fan_step_table[i].off[TEMP_CPU])
+				current_level = i - 1;
+			else
+				break;
+		}
+	} else if (temp[TEMP_CPU] > prev_tmp[TEMP_CPU]) {
+		for (i = current_level; i < NUM_FAN_LEVELS; i++) {
+			if (temp[TEMP_CPU] >= fan_step_table[i].on[TEMP_CPU])
+				current_level = i;
+			else
+				break;
+		}
+	}
+
+	if (current_level < 0)
+		current_level = 0;
+
+	if (current_level >= NUM_FAN_LEVELS)
+		current_level = NUM_FAN_LEVELS - 1;
+
+	for (i = 0; i < TEMP_SENSOR_COUNT; ++i)
+		prev_tmp[i] = temp[i];
+
+	return fan_step_table[current_level].rpm[fan];
+}
+
+void board_override_fan_control(int fan, int *temp)
+{
+	/*
+	 * In common/fan.c pwm_fan_stop() will turn off fan
+	 * when chipset suspend or shutdown.
+	 */
+	if (chipset_in_state(CHIPSET_STATE_ON)) {
+		fan_set_rpm_mode(fan, 1);
+		fan_set_rpm_target(fan, fan_table_to_rpm(fan, temp));
+	}
+}