power: supply: sbs-battery: add MANUFACTURE_DATE support

Expose the battery's manufacture date to userspace.
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/sbs-battery.c

@@ -58,6 +58,8 @@ enum {
 #define SBS_VERSION_1_1			2
 #define SBS_VERSION_1_1_WITH_PEC	3
 
+#define REG_ADDR_MANUFACTURE_DATE	0x1B
+
 /* Battery Mode defines */
 #define BATTERY_MODE_OFFSET		0x03
 #define BATTERY_MODE_CAPACITY_MASK	BIT(15)
@@ -171,6 +173,9 @@ static enum power_supply_property sbs_properties[] = {
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
+	POWER_SUPPLY_PROP_MANUFACTURE_YEAR,
+	POWER_SUPPLY_PROP_MANUFACTURE_MONTH,
+	POWER_SUPPLY_PROP_MANUFACTURE_DAY,
 	/* Properties of type `const char *' */
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_MODEL_NAME
@@ -682,6 +687,38 @@ static int sbs_get_chemistry(struct i2c_client *client,
 	return 0;
 }
 
+static int sbs_get_battery_manufacture_date(struct i2c_client *client,
+	enum power_supply_property psp,
+	union power_supply_propval *val)
+{
+	int ret;
+	u16 day, month, year;
+
+	ret = sbs_read_word_data(client, REG_ADDR_MANUFACTURE_DATE);
+	if (ret < 0)
+		return ret;
+
+	day   = ret   & GENMASK(4,  0);
+	month = (ret  & GENMASK(8,  5)) >> 5;
+	year  = ((ret & GENMASK(15, 9)) >> 9) + 1980;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_MANUFACTURE_YEAR:
+		val->intval = year;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURE_MONTH:
+		val->intval = month;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURE_DAY:
+		val->intval = day;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int sbs_get_property(struct power_supply *psy,
 	enum power_supply_property psp,
 	union power_supply_propval *val)
@@ -790,6 +827,12 @@ static int sbs_get_property(struct power_supply *psy,
 		val->strval = manufacturer;
 		break;
 
+	case POWER_SUPPLY_PROP_MANUFACTURE_YEAR:
+	case POWER_SUPPLY_PROP_MANUFACTURE_MONTH:
+	case POWER_SUPPLY_PROP_MANUFACTURE_DAY:
+		ret = sbs_get_battery_manufacture_date(client, psp, val);
+		break;
+
 	default:
 		dev_err(&client->dev,
 			"%s: INVALID property\n", __func__);