Add information for battery presence

Copy this over from the EC code base so that volteer can detect its
battery,

BUG=b:175248556
TEST=build and boot on volteer (no actual test)

Cq-Depend: chromium:2600337
Change-Id: I6ba05ab09e23a2a5aaa8c4d5f13665ce58836dac
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/zephyr-chrome/+/2599491
Reviewed-by: Keith Short <keithshort@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Commit-Queue: Simon Glass <sjg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2630163
Tested-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>

3 files changed, 91 insertions, 0 deletions

diff --git a/zephyr/projects/volteer/CMakeLists.txt b/zephyr/projects/volteer/CMakeLists.txt
index e73a98bb37..fd5ed88bfe 100644
--- a/zephyr/projects/volteer/CMakeLists.txt
+++ b/zephyr/projects/volteer/CMakeLists.txt
@@ -21,4 +21,5 @@ project(volteer)
 
 # Include board specific header files
 zephyr_include_directories(include)
+target_sources(app PRIVATE "src/battery_presence.c")
 target_sources(app PRIVATE "src/pwrok_signals.c")
diff --git a/zephyr/projects/volteer/include/gpio_map.h b/zephyr/projects/volteer/include/gpio_map.h
index f23d1db1bb..f3bed679b1 100644
--- a/zephyr/projects/volteer/include/gpio_map.h
+++ b/zephyr/projects/volteer/include/gpio_map.h
@@ -23,6 +23,7 @@
  */
 #define GPIO_AC_PRESENT            NAMED_GPIO(acok_od)
 #define GPIO_CPU_PROCHOT           NAMED_GPIO(ec_prochot_odl)
+#define GPIO_EC_BATT_PRES_ODL      NAMED_GPIO(ec_batt_pres_odl)
 #define GPIO_EC_PCH_SYS_PWROK      NAMED_GPIO(ec_pch_sys_pwrok)
 #define GPIO_EN_PP3300_A           NAMED_GPIO(en_pp3300_a)
 #define GPIO_EN_PP5000             NAMED_GPIO(en_pp5000_a)
diff --git a/zephyr/projects/volteer/src/battery_presence.c b/zephyr/projects/volteer/src/battery_presence.c
new file mode 100644
index 0000000000..4953d7a49e
--- /dev/null
+++ b/zephyr/projects/volteer/src/battery_presence.c
@@ -0,0 +1,89 @@
+/* Copyright 2019 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.
+ *
+ * Common battery presence checking for Volteer family.
+ * Each board should implement board_battery_info[] to define the specific
+ * battery packs supported.
+ */
+#include <stdbool.h>
+
+#include "battery.h"
+#include "battery_smart.h"
+#include "gpio.h"
+
+static enum battery_present batt_pres_prev = BP_NOT_SURE;
+
+enum battery_present battery_hw_present(void)
+{
+	/* The GPIO is low when the battery is physically present */
+	return gpio_get_level(GPIO_EC_BATT_PRES_ODL) ? BP_NO : BP_YES;
+}
+
+static bool battery_init(void)
+{
+	int batt_status;
+
+	return battery_status(&batt_status) ? 0 :
+		!!(batt_status & STATUS_INITIALIZED);
+}
+
+__overridable bool board_battery_is_initialized(void)
+{
+	/*
+	 * Set default to return true
+	 */
+	return true;
+}
+
+/*
+ * Physical detection of battery.
+ */
+static enum battery_present battery_check_present_status(void)
+{
+	enum battery_present batt_pres;
+	bool batt_initialization_state;
+
+	/* 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_YES)
+		return batt_pres;
+
+	/*
+	 * If the battery is present now and was present last time we checked,
+	 * return early.
+	 */
+	if (batt_pres == batt_pres_prev)
+		return batt_pres;
+
+	/*
+	 * 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.
+	 */
+	batt_initialization_state = board_battery_is_initialized();
+	if (!batt_initialization_state)
+		return BP_NOT_SURE;
+	/*
+	 * Ensure that battery is:
+	 * 1. Not in cutoff
+	 * 2. Initialized
+	 */
+	if (battery_is_cut_off() || !battery_init())
+		batt_pres = BP_NO;
+
+	return batt_pres;
+}
+
+enum battery_present battery_is_present(void)
+{
+	batt_pres_prev = battery_check_present_status();
+	return batt_pres_prev;
+}