1 files changed, 81 insertions, 0 deletions
diff --git a/zephyr/program/skyrim/winterhold/src/battery_present.c b/zephyr/program/skyrim/winterhold/src/battery_present.c
new file mode 100644
index 0000000000..290955a242
--- /dev/null
+++ b/zephyr/program/skyrim/winterhold/src/battery_present.c
@@ -0,0 +1,81 @@
+/* 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.
+ */
+#include "battery.h"
+#include "battery_smart.h"
+#include "common.h"
+
+#include <zephyr/drivers/gpio.h>
+
+static enum battery_present batt_pres_prev = BP_NOT_SURE;
+
+__overridable bool board_battery_is_initialized(void)
+{
+	int batt_status;
+
+	return battery_status(&batt_status) != EC_SUCCESS ?
+		       false :
+		       !!(batt_status & STATUS_INITIALIZED);
+}
+
+/*
+ * Physical detection of battery.
+ */
+static enum battery_present battery_check_present_status(void)
+{
+	enum battery_present batt_pres;
+
+	if (battery_is_cut_off())
+		return BP_NO;
+
+	/* Get the physical hardware status */
+	batt_pres = battery_hw_present();
+
+	/*
+	 * If the battery is not physically connected, then no need to perform
+	 * any more checks.
+	 */
+	if (batt_pres == BP_NO)
+		return BP_NO;
+
+	/*
+	 * If the battery is present now and was present last time we checked,
+	 * return early.
+	 */
+	if ((batt_pres == BP_YES) && (batt_pres == batt_pres_prev))
+		return BP_YES;
+
+	/*
+	 * Check battery initialization. If the battery is not initialized,
+	 * then return BP_NOT_SURE. Battery could be in ship
+	 * mode and might require pre-charge current to wake it up. BP_NO is not
+	 * returned here because charger state machine will not provide
+	 * pre-charge current assuming that battery is not present.
+	 */
+	if (!board_battery_is_initialized())
+		return BP_NOT_SURE;
+
+	return BP_YES;
+}
+
+enum battery_present battery_is_present(void)
+{
+	batt_pres_prev = battery_check_present_status();
+	return batt_pres_prev;
+}
+
+enum battery_present battery_hw_present(void)
+{
+	const struct gpio_dt_spec *batt_pres;
+
+	batt_pres = GPIO_DT_FROM_NODELABEL(gpio_ec_batt_pres_odl);
+
+	/*
+	 * The GPIO is low when the battery is physically present.
+	 * But if battery cell voltage < 2.5V, it will not able to
+	 * pull down EC_BATT_PRES_ODL. So we need to set pre-charge
+	 * current even EC_BATT_PRES_ODL is high.
+	 */
+	return gpio_pin_get_dt(batt_pres) ? BP_NOT_SURE : BP_YES;
+}