1 files changed, 113 insertions, 43 deletions

diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index 7efb908f4451..08e4fd9ee607 100644
--- a/drivers/power/supply/ltc2941-battery-gauge.c
+++ b/drivers/power/supply/ltc2941-battery-gauge.c
@@ -1,6 +1,6 @@
 /*
- * I2C client/driver for the Linear Technology LTC2941 and LTC2943
- * Battery Gas Gauge IC
+ * I2C client/driver for the Linear Technology LTC2941, LTC2942, LTC2943
+ * and LTC2944 Battery Gas Gauge IC
  *
  * Copyright (C) 2014 Topic Embedded Systems
  *
@@ -34,35 +34,39 @@ enum ltc294x_reg {
 	LTC294X_REG_CONTROL		= 0x01,
 	LTC294X_REG_ACC_CHARGE_MSB	= 0x02,
 	LTC294X_REG_ACC_CHARGE_LSB	= 0x03,
-	LTC294X_REG_THRESH_HIGH_MSB	= 0x04,
-	LTC294X_REG_THRESH_HIGH_LSB	= 0x05,
-	LTC294X_REG_THRESH_LOW_MSB	= 0x06,
-	LTC294X_REG_THRESH_LOW_LSB	= 0x07,
-	LTC294X_REG_VOLTAGE_MSB	= 0x08,
-	LTC294X_REG_VOLTAGE_LSB	= 0x09,
-	LTC294X_REG_CURRENT_MSB	= 0x0E,
-	LTC294X_REG_CURRENT_LSB	= 0x0F,
-	LTC294X_REG_TEMPERATURE_MSB	= 0x14,
-	LTC294X_REG_TEMPERATURE_LSB	= 0x15,
+	LTC294X_REG_VOLTAGE_MSB		= 0x08,
+	LTC294X_REG_VOLTAGE_LSB		= 0x09,
+	LTC2942_REG_TEMPERATURE_MSB	= 0x0C,
+	LTC2942_REG_TEMPERATURE_LSB	= 0x0D,
+	LTC2943_REG_CURRENT_MSB		= 0x0E,
+	LTC2943_REG_CURRENT_LSB		= 0x0F,
+	LTC2943_REG_TEMPERATURE_MSB	= 0x14,
+	LTC2943_REG_TEMPERATURE_LSB	= 0x15,
 };
 
-#define LTC2943_REG_CONTROL_MODE_MASK (BIT(7) | BIT(6))
-#define LTC2943_REG_CONTROL_MODE_SCAN BIT(7)
+enum ltc294x_id {
+	LTC2941_ID,
+	LTC2942_ID,
+	LTC2943_ID,
+	LTC2944_ID,
+};
+
+#define LTC2941_REG_STATUS_CHIP_ID	BIT(7)
+
+#define LTC2942_REG_CONTROL_MODE_SCAN	(BIT(7) | BIT(6))
+#define LTC2943_REG_CONTROL_MODE_SCAN	BIT(7)
 #define LTC294X_REG_CONTROL_PRESCALER_MASK	(BIT(5) | BIT(4) | BIT(3))
 #define LTC294X_REG_CONTROL_SHUTDOWN_MASK	(BIT(0))
 #define LTC294X_REG_CONTROL_PRESCALER_SET(x) \
 	((x << 3) & LTC294X_REG_CONTROL_PRESCALER_MASK)
 #define LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED	0
 
-#define LTC2941_NUM_REGS	0x08
-#define LTC2943_NUM_REGS	0x18
-
 struct ltc294x_info {
 	struct i2c_client *client;	/* I2C Client pointer */
 	struct power_supply *supply;	/* Supply pointer */
 	struct power_supply_desc supply_desc;	/* Supply description */
 	struct delayed_work work;	/* Work scheduler */
-	unsigned long num_regs;	/* Number of registers (chip type) */
+	enum ltc294x_id id;		/* Chip type */
 	int charge;	/* Last charge register content */
 	int r_sense;	/* mOhm */
 	int Qlsb;	/* nAh */
@@ -145,9 +149,18 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
 
 	control = LTC294X_REG_CONTROL_PRESCALER_SET(prescaler_exp) |
 				LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED;
-	/* Put the 2943 into "monitor" mode, so it measures every 10 sec */
-	if (info->num_regs == LTC2943_NUM_REGS)
+	/* Put device into "monitor" mode */
+	switch (info->id) {
+	case LTC2942_ID:	/* 2942 measures every 2 sec */
+		control |= LTC2942_REG_CONTROL_MODE_SCAN;
+		break;
+	case LTC2943_ID:
+	case LTC2944_ID:	/* 2943 and 2944 measure every 10 sec */
 		control |= LTC2943_REG_CONTROL_MODE_SCAN;
+		break;
+	default:
+		break;
+	}
 
 	if (value != control) {
 		ret = ltc294x_write_regs(info->client,
@@ -252,7 +265,24 @@ static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
 	ret = ltc294x_read_regs(info->client,
 		LTC294X_REG_VOLTAGE_MSB, &datar[0], 2);
 	value = (datar[0] << 8) | datar[1];
-	*val = ((value * 23600) / 0xFFFF) * 1000; /* in uV */
+	switch (info->id) {
+	case LTC2943_ID:
+		value *= 23600 * 2;
+		value /= 0xFFFF;
+		value *= 1000 / 2;
+		break;
+	case LTC2944_ID:
+		value *= 70800 / 5*4;
+		value /= 0xFFFF;
+		value *= 1000 * 5/4;
+		break;
+	default:
+		value *= 6000 * 10;
+		value /= 0xFFFF;
+		value *= 1000 / 10;
+		break;
+	}
+	*val = value;
 	return ret;
 }
 
@@ -263,27 +293,38 @@ static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
 	s32 value;
 
 	ret = ltc294x_read_regs(info->client,
-		LTC294X_REG_CURRENT_MSB, &datar[0], 2);
+		LTC2943_REG_CURRENT_MSB, &datar[0], 2);
 	value = (datar[0] << 8) | datar[1];
 	value -= 0x7FFF;
+	if (info->id == LTC2944_ID)
+		value *= 64000;
+	else
+		value *= 60000;
 	/* Value is in range -32k..+32k, r_sense is usually 10..50 mOhm,
 	 * the formula below keeps everything in s32 range while preserving
 	 * enough digits */
-	*val = 1000 * ((60000 * value) / (info->r_sense * 0x7FFF)); /* in uA */
+	*val = 1000 * (value / (info->r_sense * 0x7FFF)); /* in uA */
 	return ret;
 }
 
 static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
 {
+	enum ltc294x_reg reg;
 	int ret;
 	u8 datar[2];
 	u32 value;
 
-	ret = ltc294x_read_regs(info->client,
-		LTC294X_REG_TEMPERATURE_MSB, &datar[0], 2);
-	value = (datar[0] << 8) | datar[1];
-	/* Full-scale is 510 Kelvin, convert to centidegrees  */
-	*val = (((51000 * value) / 0xFFFF) - 27215);
+	if (info->id == LTC2942_ID) {
+		reg = LTC2942_REG_TEMPERATURE_MSB;
+		value = 60000;	/* Full-scale is 600 Kelvin */
+	} else {
+		reg = LTC2943_REG_TEMPERATURE_MSB;
+		value = 51000;	/* Full-scale is 510 Kelvin */
+	}
+	ret = ltc294x_read_regs(info->client, reg, &datar[0], 2);
+	value *= (datar[0] << 8) | datar[1];
+	/* Convert to centidegrees  */
+	*val = value / 0xFFFF - 27215;
 	return ret;
 }
 
@@ -357,8 +398,8 @@ static enum power_supply_property ltc294x_properties[] = {
 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
 	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
-	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
 };
 
 static int ltc294x_i2c_remove(struct i2c_client *client)
@@ -375,10 +416,11 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 {
 	struct power_supply_config psy_cfg = {};
 	struct ltc294x_info *info;
+	struct device_node *np;
 	int ret;
 	u32 prescaler_exp;
 	s32 r_sense;
-	struct device_node *np;
+	u8 status;
 
 	info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
 	if (info == NULL)
@@ -388,7 +430,7 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 
 	np = of_node_get(client->dev.of_node);
 
-	info->num_regs = (unsigned long)of_device_get_match_data(&client->dev);
+	info->id = (enum ltc294x_id)of_device_get_match_data(&client->dev);
 	info->supply_desc.name = np->name;
 
 	/* r_sense can be negative, when sense+ is connected to the battery
@@ -409,7 +451,7 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 		prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
 	}
 
-	if (info->num_regs == LTC2943_NUM_REGS) {
+	if (info->id == LTC2943_ID) {
 		if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
 			prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
 		info->Qlsb = ((340 * 50000) / r_sense) /
@@ -421,21 +463,39 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 				(128 / (1 << prescaler_exp));
 	}
 
+	/* Read status register to check for LTC2942 */
+	if (info->id == LTC2941_ID || info->id == LTC2942_ID) {
+		ret = ltc294x_read_regs(client, LTC294X_REG_STATUS, &status, 1);
+		if (ret < 0) {
+			dev_err(&client->dev,
+				"Could not read status register\n");
+			return ret;
+		}
+		if (status & LTC2941_REG_STATUS_CHIP_ID)
+			info->id = LTC2941_ID;
+		else
+			info->id = LTC2942_ID;
+	}
+
 	info->client = client;
 	info->supply_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 	info->supply_desc.properties = ltc294x_properties;
-	if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
+	switch (info->id) {
+	case LTC2944_ID:
+	case LTC2943_ID:
 		info->supply_desc.num_properties =
 			ARRAY_SIZE(ltc294x_properties);
-	else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
+		break;
+	case LTC2942_ID:
 		info->supply_desc.num_properties =
 			ARRAY_SIZE(ltc294x_properties) - 1;
-	else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
-		info->supply_desc.num_properties =
-			ARRAY_SIZE(ltc294x_properties) - 2;
-	else
+		break;
+	case LTC2941_ID:
+	default:
 		info->supply_desc.num_properties =
 			ARRAY_SIZE(ltc294x_properties) - 3;
+		break;
+	}
 	info->supply_desc.get_property = ltc294x_get_property;
 	info->supply_desc.set_property = ltc294x_set_property;
 	info->supply_desc.property_is_writeable = ltc294x_property_is_writeable;
@@ -492,8 +552,10 @@ static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
 
 
 static const struct i2c_device_id ltc294x_i2c_id[] = {
-	{"ltc2941", LTC2941_NUM_REGS},
-	{"ltc2943", LTC2943_NUM_REGS},
+	{ "ltc2941", LTC2941_ID, },
+	{ "ltc2942", LTC2942_ID, },
+	{ "ltc2943", LTC2943_ID, },
+	{ "ltc2944", LTC2944_ID, },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
@@ -501,11 +563,19 @@ MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
 static const struct of_device_id ltc294x_i2c_of_match[] = {
 	{
 		.compatible = "lltc,ltc2941",
-		.data = (void *)LTC2941_NUM_REGS
+		.data = (void *)LTC2941_ID,
+	},
+	{
+		.compatible = "lltc,ltc2942",
+		.data = (void *)LTC2942_ID,
 	},
 	{
 		.compatible = "lltc,ltc2943",
-		.data = (void *)LTC2943_NUM_REGS
+		.data = (void *)LTC2943_ID,
+	},
+	{
+		.compatible = "lltc,ltc2944",
+		.data = (void *)LTC2944_ID,
 	},
 	{ },
 };
@@ -525,5 +595,5 @@ module_i2c_driver(ltc294x_driver);
 
 MODULE_AUTHOR("Auryn Verwegen, Topic Embedded Systems");
 MODULE_AUTHOR("Mike Looijmans, Topic Embedded Products");
-MODULE_DESCRIPTION("LTC2941/LTC2943 Battery Gas Gauge IC driver");
+MODULE_DESCRIPTION("LTC2941/LTC2942/LTC2943/LTC2944 Battery Gas Gauge IC driver");
 MODULE_LICENSE("GPL");