bq20z75: Add support for charge properties

Adding support for charge properties for gas gauge.

Also ensuring that battery mode is correct now for energy as well as
charge properties by setting it on the fly.

I also added 2 functions to power_supply.h to help identify the units for
specific properties more easily by power supplies.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c
index 492da27..4141775 100644
--- a/drivers/power/bq20z75.c
+++ b/drivers/power/bq20z75.c
@@ -38,11 +38,22 @@
 	REG_CYCLE_COUNT,
 	REG_SERIAL_NUMBER,
 	REG_REMAINING_CAPACITY,
+	REG_REMAINING_CAPACITY_CHARGE,
 	REG_FULL_CHARGE_CAPACITY,
+	REG_FULL_CHARGE_CAPACITY_CHARGE,
 	REG_DESIGN_CAPACITY,
+	REG_DESIGN_CAPACITY_CHARGE,
 	REG_DESIGN_VOLTAGE,
 };
 
+/* Battery Mode defines */
+#define BATTERY_MODE_OFFSET		0x03
+#define BATTERY_MODE_MASK		0x8000
+enum bq20z75_battery_mode {
+	BATTERY_MODE_AMPS,
+	BATTERY_MODE_WATTS
+};
+
 /* manufacturer access defines */
 #define MANUFACTURER_ACCESS_STATUS	0x0006
 #define MANUFACTURER_ACCESS_SLEEP	0x0011
@@ -78,8 +89,12 @@
 		BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
 	[REG_REMAINING_CAPACITY] =
 		BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
+	[REG_REMAINING_CAPACITY_CHARGE] =
+		BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_NOW, 0x0F, 0, 65535),
 	[REG_FULL_CHARGE_CAPACITY] =
 		BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
+	[REG_FULL_CHARGE_CAPACITY_CHARGE] =
+		BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_FULL, 0x10, 0, 65535),
 	[REG_TIME_TO_EMPTY] =
 		BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
 			65535),
@@ -93,6 +108,9 @@
 	[REG_DESIGN_CAPACITY] =
 		BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0,
 			65535),
+	[REG_DESIGN_CAPACITY_CHARGE] =
+		BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 0x18, 0,
+			65535),
 	[REG_DESIGN_VOLTAGE] =
 		BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0,
 			65535),
@@ -117,6 +135,9 @@
 	POWER_SUPPLY_PROP_ENERGY_NOW,
 	POWER_SUPPLY_PROP_ENERGY_FULL,
 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 };
 
 struct bq20z75_info {
@@ -260,6 +281,9 @@
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 		val->intval *= BASE_UNIT_CONVERSION;
 		break;
 
@@ -281,11 +305,44 @@
 	}
 }
 
+static enum bq20z75_battery_mode
+bq20z75_set_battery_mode(struct i2c_client *client,
+	enum bq20z75_battery_mode mode)
+{
+	int ret, original_val;
+
+	original_val = bq20z75_read_word_data(client, BATTERY_MODE_OFFSET);
+	if (original_val < 0)
+		return original_val;
+
+	if ((original_val & BATTERY_MODE_MASK) == mode)
+		return mode;
+
+	if (mode == BATTERY_MODE_AMPS)
+		ret = original_val & ~BATTERY_MODE_MASK;
+	else
+		ret = original_val | BATTERY_MODE_MASK;
+
+	ret = bq20z75_write_word_data(client, BATTERY_MODE_OFFSET, ret);
+	if (ret < 0)
+		return ret;
+
+	return original_val & BATTERY_MODE_MASK;
+}
+
 static int bq20z75_get_battery_capacity(struct i2c_client *client,
 	int reg_offset, enum power_supply_property psp,
 	union power_supply_propval *val)
 {
 	s32 ret;
+	enum bq20z75_battery_mode mode = BATTERY_MODE_WATTS;
+
+	if (power_supply_is_amp_property(psp))
+		mode = BATTERY_MODE_AMPS;
+
+	mode = bq20z75_set_battery_mode(client, mode);
+	if (mode < 0)
+		return mode;
 
 	ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
 	if (ret < 0)
@@ -298,6 +355,10 @@
 	} else
 		val->intval = ret;
 
+	ret = bq20z75_set_battery_mode(client, mode);
+	if (ret < 0)
+		return ret;
+
 	return 0;
 }
 
@@ -318,11 +379,25 @@
 	return 0;
 }
 
+static int bq20z75_get_property_index(struct i2c_client *client,
+	enum power_supply_property psp)
+{
+	int count;
+	for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++)
+		if (psp == bq20z75_data[count].psp)
+			return count;
+
+	dev_warn(&client->dev,
+		"%s: Invalid Property - %d\n", __func__, psp);
+
+	return -EINVAL;
+}
+
 static int bq20z75_get_property(struct power_supply *psy,
 	enum power_supply_property psp,
 	union power_supply_propval *val)
 {
-	int count;
+	int ps_index;
 	int ret;
 	struct bq20z75_info *bq20z75_device = container_of(psy,
 				struct bq20z75_info, power_supply);
@@ -343,13 +418,15 @@
 	case POWER_SUPPLY_PROP_ENERGY_NOW:
 	case POWER_SUPPLY_PROP_ENERGY_FULL:
 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 	case POWER_SUPPLY_PROP_CAPACITY:
-		for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
-			if (psp == bq20z75_data[count].psp)
-				break;
-		}
+		ps_index = bq20z75_get_property_index(client, psp);
+		if (ps_index < 0)
+			return ps_index;
 
-		ret = bq20z75_get_battery_capacity(client, count, psp, val);
+		ret = bq20z75_get_battery_capacity(client, ps_index, psp, val);
 		if (ret)
 			return ret;
 
@@ -369,12 +446,11 @@
 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
-		for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
-			if (psp == bq20z75_data[count].psp)
-				break;
-		}
+		ps_index = bq20z75_get_property_index(client, psp);
+		if (ps_index < 0)
+			return ps_index;
 
-		ret = bq20z75_get_battery_property(client, count, psp, val);
+		ret = bq20z75_get_battery_property(client, ps_index, psp, val);
 		if (ret)
 			return ret;