Peppy: Detect physical presence of battery before waking it

BUG=chrome-os-partner:20889
BRANCH=peppy
TEST=Power device without battery. It should boot with no 30
second delay. The battery LED blinks orange indicating a
battery error.

Change-Id: Iea4f5644ae223b60dc8058dc52e06405e275c001
Signed-off-by: Dave Parker <dparker@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/61820
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Tested-by: Marc Jones <marc.jones@se-eng.com>

6 files changed, 47 insertions, 10 deletions

diff --git a/board/peppy/board.c b/board/peppy/board.c
index 86ee193ab0..61bf94d7b1 100644
--- a/board/peppy/board.c
+++ b/board/peppy/board.c
@@ -70,6 +70,7 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"BOARD_VERSION2",       LM4_GPIO_Q, (1<<6), GPIO_INPUT, NULL},
 	{"BOARD_VERSION3",       LM4_GPIO_Q, (1<<7), GPIO_INPUT, NULL},
 	{"CPU_PGOOD",            LM4_GPIO_C, (1<<4), GPIO_INPUT, NULL},
+	{"BAT_DETECT_L",         LM4_GPIO_B, (1<<4), GPIO_INPUT, NULL},
 
 	/* Outputs; all unasserted by default except for reset signals */
 	{"CPU_PROCHOT",          LM4_GPIO_B, (1<<1), GPIO_OUT_LOW, NULL},
diff --git a/board/peppy/board.h b/board/peppy/board.h
index 6b2be7703b..52517bedb6 100644
--- a/board/peppy/board.h
+++ b/board/peppy/board.h
@@ -17,6 +17,7 @@
 /* Optional features */
 #define CONFIG_SMART_BATTERY
 #define CONFIG_BACKLIGHT_X86
+#define CONFIG_BATTERY_CHECK_CONNECTED
 #define CONFIG_BATTERY_PEPPY
 #define CONFIG_BOARD_VERSION
 #define CONFIG_CHARGER
@@ -98,6 +99,7 @@ enum gpio_signal {
 	GPIO_BOARD_VERSION2,       /* Board version stuffing resistor 2 */
 	GPIO_BOARD_VERSION3,       /* Board version stuffing resistor 3 */
 	GPIO_CPU_PGOOD,            /* Power good to the CPU */
+	GPIO_BAT_DETECT_L,         /* Battery detect. Repurposed BAT_TEMP */
 
 	/* Outputs */
 	GPIO_CPU_PROCHOT,          /* Force CPU to think it's overheated */
diff --git a/common/battery_peppy.c b/common/battery_peppy.c
index 9672eeef87..086469c9a3 100644
--- a/common/battery_peppy.c
+++ b/common/battery_peppy.c
@@ -6,6 +6,7 @@
  */
 
 #include "battery_pack.h"
+#include "gpio.h"
 #include "host_command.h"
 #include "smart_battery.h"
 
@@ -62,3 +63,11 @@ int battery_command_cut_off(struct host_cmd_handler_args *args)
 }
 DECLARE_HOST_COMMAND(EC_CMD_BATTERY_CUT_OFF, battery_command_cut_off,
 		     EC_VER_MASK(0));
+
+/**
+ * Physical detection of battery connection.
+ */
+int battery_is_connected(void)
+{
+	return (gpio_get_level(GPIO_BAT_DETECT_L) == 0);
+}
diff --git a/common/charge_state.c b/common/charge_state.c
index 61b17a2193..e0646c80c5 100644
--- a/common/charge_state.c
+++ b/common/charge_state.c
@@ -175,12 +175,20 @@ static int state_common(struct power_state_context *ctx)
 		state_machine_force_idle = 0;
 	}
 
+#ifdef CONFIG_BATTERY_CHECK_CONNECTED
+	if (!battery_is_connected()) {
+		curr->error |= F_BATTERY_NOT_CONNECTED;
+		return curr->error;
+	}
+#endif /* CONFIG_BATTERY_CHECK_CONNECTED */
+
+	/* Read temperature and see if battery is responsive */
 	rv = battery_temperature(&batt->temperature);
 	if (rv) {
 		/* Check low battery condition and retry */
-		if (curr->ac && ctx->battery_present == 1 &&
+		if (curr->ac && ctx->battery_responsive &&
 		    !(curr->error & F_CHARGER_MASK)) {
-			ctx->battery_present = 0;
+			ctx->battery_responsive = 0;
 			/*
 			 * Try to revive ultra low voltage pack.  Charge
 			 * battery pack with minimum current and maximum
@@ -192,17 +200,19 @@ static int state_common(struct power_state_context *ctx)
 				sleep(1);
 				rv = battery_temperature(&batt->temperature);
 				if (rv == 0) {
-					ctx->battery_present = 1;
+					ctx->battery_responsive = 1;
 					break;
 				}
 			}
 		}
 
 		/* Set error if battery is still unresponsive */
-		if (rv)
-			curr->error |= F_BATTERY_TEMPERATURE;
+		if (rv) {
+			curr->error |= F_BATTERY_UNRESPONSIVE;
+			return curr->error;
+		}
 	} else {
-		ctx->battery_present = 1;
+		ctx->battery_responsive = 1;
 	}
 
 	if (battery_voltage(&batt->voltage))
@@ -785,7 +795,8 @@ static void charge_init(void)
 	ctx->trickle_charging_time.val = 0;
 	ctx->battery = battery_get_info();
 	ctx->charger = charger_get_info();
-	ctx->battery_present = 1;
+	/* Assume the battery is responsive until proven otherwise */
+	ctx->battery_responsive = 1;
 
 	/* Set up LPC direct memmap */
 	ctx->memmap_batt_volt =
diff --git a/include/battery_pack.h b/include/battery_pack.h
index 620b99e374..0367ee8406 100644
--- a/include/battery_pack.h
+++ b/include/battery_pack.h
@@ -7,6 +7,8 @@
 #ifndef __CROS_EC_BATTERY_PACK_H
 #define __CROS_EC_BATTERY_PACK_H
 
+#include "common.h"
+
 #define CELSIUS_TO_DECI_KELVIN(temp_c) ((temp_c) * 10 + 2731)
 
 /* Battery parameters */
@@ -46,4 +48,13 @@ const struct battery_info *battery_get_info(void);
  */
 void battery_vendor_params(struct batt_params *batt);
 
-#endif
+#ifdef CONFIG_BATTERY_CHECK_CONNECTED
+/**
+ * Attempt communication with the battery.
+ *
+ * @return non-zero if the battery responds.
+ */
+int battery_is_connected(void);
+#endif /* CONFIG_BATTERY_CHECK_CONNECTED */
+
+#endif /* __CROS_EC_BATTERY_PACK_H */
diff --git a/include/charge_state.h b/include/charge_state.h
index d9816a7a9d..bd8f576b55 100644
--- a/include/charge_state.h
+++ b/include/charge_state.h
@@ -32,11 +32,14 @@
 #define F_BATTERY_MODE        (1 << 8) /* Battery mode */
 #define F_BATTERY_CAPACITY    (1 << 9) /* Battery capacity */
 #define F_BATTERY_STATE_OF_CHARGE (1 << 10) /* State of charge, percentage */
+#define F_BATTERY_UNRESPONSIVE    (1 << 11) /* Battery not responding */
+#define F_BATTERY_NOT_CONNECTED   (1 << 12) /* Battery not connected */
 
 #define F_BATTERY_MASK (F_BATTERY_VOLTAGE | F_BATTERY_CURRENT |  \
 			F_DESIRED_VOLTAGE | F_DESIRED_CURRENT |  \
 			F_BATTERY_TEMPERATURE | F_BATTERY_MODE | \
-			F_BATTERY_CAPACITY | F_BATTERY_STATE_OF_CHARGE)
+			F_BATTERY_CAPACITY | F_BATTERY_STATE_OF_CHARGE | \
+			F_BATTERY_UNRESPONSIVE | F_BATTERY_NOT_CONNECTED)
 #define F_CHARGER_MASK (F_CHARGER_VOLTAGE | F_CHARGER_CURRENT | \
 			F_CHARGER_INIT)
 
@@ -118,7 +121,7 @@ struct power_state_context {
 	timestamp_t trickle_charging_time;
 	timestamp_t voltage_debounce_time;
 	timestamp_t shutdown_warning_time;
-	int battery_present;
+	int battery_responsive;
 };
 
 /* Trickle charging state handler.