Rename and document battery constants

In preparation for cleaning up low-battery logic.  Make clear what
comparison operator is used for each constant (<=, <, >=, >).

Also remove hard-coded and unused display of design warning/low
battery levels from ectool.  Verified via code search that these are
not used anywhere.  Even if we later care about these levels, they
should be battery-specific and not hard-coded as a
platform-independent percentage of full capacity when ectool is
compiled.

BUG=chrome-os-partner:17124
BRANCH=link
TEST=compile link; 'ectool battery' from root shell prints valid info

Original-Change-Id: I3650e27a08f4cc77067beb0685ee1488cc56d02f
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/43119
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
(cherry picked from commit 9fde14da9b2e8d8944e66c5b8f4798e0c40be72e)

Change-Id: Id74d55fed9bb306e9cf5a0aed86caf81ec2fe7d0
Reviewed-on: https://gerrit.chromium.org/gerrit/44686
Commit-Queue: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Tested-by: Randall Spangler <rspangler@chromium.org>

3 files changed, 29 insertions, 33 deletions

diff --git a/common/charge_state.c b/common/charge_state.c
index 60f4c4de79..ddf11f6c7e 100644
--- a/common/charge_state.c
+++ b/common/charge_state.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+/* Copyright (c) 2013 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.
  *
@@ -357,14 +357,14 @@ static enum power_state state_idle(struct power_state_context *ctx)
 	    ctx->curr.charging_current)
 		return PWR_STATE_INIT;
 
-	if (batt->state_of_charge >= STOP_CHARGE_THRESHOLD)
+	if (batt->state_of_charge >= BATTERY_LEVEL_FULL)
 		return PWR_STATE_UNCHANGE;
 
 	/* Configure init charger state and switch to charge state */
 	if (batt->desired_voltage && batt->desired_current) {
 		/* Set charger output constraints */
 		if (batt->desired_current < ctx->charger->current_min &&
-		    batt->state_of_charge < PRE_CHARGE_THRESHOLD) {
+		    batt->state_of_charge < BATTERY_LEVEL_PRE_CHARGE) {
 			/* Trickle charging */
 			if (charger_set_current(c_info->current_min) ||
 			    charger_set_voltage(batt->voltage))
@@ -384,7 +384,7 @@ static enum power_state state_idle(struct power_state_context *ctx)
 		}
 		update_charger_time(ctx, get_time());
 
-		if (ctx->curr.batt.state_of_charge < NEAR_FULL_THRESHOLD)
+		if (ctx->curr.batt.state_of_charge < BATTERY_LEVEL_NEAR_FULL)
 			return PWR_STATE_CHARGE;
 		else
 			return PWR_STATE_CHARGE_NEAR_FULL;
@@ -411,7 +411,7 @@ static enum power_state state_charge(struct power_state_context *ctx)
 
 	if (batt->desired_current < c_info->current_min &&
 	    batt->desired_current > 0 &&
-	    batt->state_of_charge < PRE_CHARGE_THRESHOLD)
+	    batt->state_of_charge < BATTERY_LEVEL_PRE_CHARGE)
 		return trickle_charge(ctx);
 
 	/* Check charger reset */
@@ -422,7 +422,7 @@ static enum power_state state_charge(struct power_state_context *ctx)
 	if (!curr->ac)
 		return PWR_STATE_INIT;
 
-	if (batt->state_of_charge >= STOP_CHARGE_THRESHOLD) {
+	if (batt->state_of_charge >= BATTERY_LEVEL_FULL) {
 		if (charger_set_voltage(0) || charger_set_current(0))
 			return PWR_STATE_ERROR;
 		return PWR_STATE_IDLE;
@@ -645,7 +645,7 @@ void charge_state_machine_task(void)
 			new_state = state_charge(ctx);
 			if (new_state == PWR_STATE_UNCHANGE &&
 			    (ctx->curr.batt.state_of_charge >=
-			     NEAR_FULL_THRESHOLD)) {
+			     BATTERY_LEVEL_NEAR_FULL)) {
 				/* Almost done charging */
 				new_state = PWR_STATE_CHARGE_NEAR_FULL;
 			}
@@ -655,7 +655,7 @@ void charge_state_machine_task(void)
 			new_state = state_charge(ctx);
 			if (new_state == PWR_STATE_UNCHANGE &&
 			    (ctx->curr.batt.state_of_charge <
-			     NEAR_FULL_THRESHOLD)) {
+			     BATTERY_LEVEL_NEAR_FULL)) {
 				/* Battery below almost-full threshold. */
 				new_state = PWR_STATE_CHARGE;
 			}
diff --git a/include/battery.h b/include/battery.h
index 12b10422da..da4071e158 100644
--- a/include/battery.h
+++ b/include/battery.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+/* Copyright (c) 2013 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.
  *
@@ -8,21 +8,25 @@
 #ifndef __CROS_EC_BATTERY_H
 #define __CROS_EC_BATTERY_H
 
-/* Design capacities, percentage */
-#define BATTERY_LEVEL_WARNING  15
-#define BATTERY_LEVEL_LOW      10
-#define BATTERY_LEVEL_CRITICAL 5
-/* Shut down main processor when battery level reaches this level */
-#define BATTERY_LEVEL_SHUTDOWN 3
-/* Hibernate EC immediately when battery level reaches this level */
-#define BATTERY_LEVEL_HIBERNATE_EC 2
-
-/* Stop charge when state of charge reaches this percentage */
-#define STOP_CHARGE_THRESHOLD 100
-/* Tell host we're charged at this percentage */
-#define NEAR_FULL_THRESHOLD 97
-/* Precharge only when state of charge is below this level */
-#define PRE_CHARGE_THRESHOLD 25
+/* Stop charge when charging and battery level >= this percentage */
+#define BATTERY_LEVEL_FULL		100
+/* Tell host we're charged when battery level >= this percentage */
+#define BATTERY_LEVEL_NEAR_FULL		 97
+/* Precharge only when charging and battery level < this level */
+#define BATTERY_LEVEL_PRE_CHARGE	 25
+/*
+ * Send battery-low host event when discharging and battery level <= this level
+ */
+#define BATTERY_LEVEL_LOW		 10
+/*
+ * Send battery-critical host event when discharging and battery level <= this
+ * level.
+ */
+#define BATTERY_LEVEL_CRITICAL		  5
+/* Shut down main processor when discharging and battery level < this level */
+#define BATTERY_LEVEL_SHUTDOWN		  3
+/* Hibernate EC immediately when discharging and battery level < this level */
+#define BATTERY_LEVEL_HIBERNATE_EC	  2
 
 #endif /* __CROS_EC_BATTERY_H */
 
diff --git a/util/ectool.c b/util/ectool.c
index f83ae0f3d5..d2f2979795 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+/* Copyright (c) 2013 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.
  */
@@ -2136,14 +2136,6 @@ int cmd_battery(int argc, char *argv[])
 		goto cmd_error;
 	printf("  Design output voltage   %u mV\n", val);
 
-	val = read_mapped_mem32(EC_MEMMAP_BATT_DCAP);
-	if (!is_battery_range(val))
-		goto cmd_error;
-	printf("  Design capacity warning %u mAh\n",
-		val * BATTERY_LEVEL_WARNING / 100);
-	printf("  Design capacity low     %u mAh\n",
-		val * BATTERY_LEVEL_LOW / 100);
-
 	val = read_mapped_mem32(EC_MEMMAP_BATT_CCNT);
 	if (!is_battery_range(val))
 		goto cmd_error;