power_supply: bq27x00: add BQ27500 support

BQ27500 is newer fuel gauge chip from TI with slightly changed
register layout and some different register semantics. Add new i2c
ID for it and handle differences where needed. Also rename bq27200
functions to bq27x00, as they are no longer bq27200 specific.
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/power/Kconfig

@@ -98,10 +98,10 @@ config BATTERY_WM97XX
 	  Say Y to enable support for battery measured by WM97xx aux port.
 
 config BATTERY_BQ27x00
-	tristate "BQ27200 battery driver"
+	tristate "BQ27x00 battery driver"
 	depends on I2C
 	help
-	  Say Y here to enable support for batteries with BQ27200(I2C) chip.
+	  Say Y here to enable support for batteries with BQ27x00 (I2C) chips.
 
 config BATTERY_DA9030
 	tristate "DA9030 battery driver"

drivers/power/bq27x00_battery.c

@@ -26,14 +26,17 @@
 #include <linux/i2c.h>
 #include <asm/unaligned.h>
 
-#define DRIVER_VERSION			"1.0.0"
+#define DRIVER_VERSION			"1.1.0"
 
 #define BQ27x00_REG_TEMP		0x06
 #define BQ27x00_REG_VOLT		0x08
-#define BQ27x00_REG_RSOC		0x0B /* Relative State-of-Charge */
 #define BQ27x00_REG_AI			0x14
 #define BQ27x00_REG_FLAGS		0x0A
 
+#define BQ27000_REG_RSOC		0x0B /* Relative State-of-Charge */
+
+#define BQ27500_REG_SOC			0x2c
+
 /* If the system has several batteries we need a different name for each
  * of them...
  */
@@ -46,11 +49,14 @@ struct bq27x00_access_methods {
 		struct bq27x00_device_info *di);
 };
 
+enum bq27x00_chip { BQ27000, BQ27500 };
+
 struct bq27x00_device_info {
 	struct device 		*dev;
 	int			id;
 	struct bq27x00_access_methods	*bus;
 	struct power_supply	bat;
+	enum bq27x00_chip	chip;
 
 	struct i2c_client	*client;
 };
@@ -88,7 +94,10 @@ static int bq27x00_battery_temperature(struct bq27x00_device_info *di)
 		return ret;
 	}
 
-	return ((temp >> 2) - 273) * 10;
+	if (di->chip == BQ27500)
+		return temp - 2731;
+	else
+		return ((temp >> 2) - 273) * 10;
 }
 
 /*
@@ -125,15 +134,22 @@ static int bq27x00_battery_current(struct bq27x00_device_info *di)
 		dev_err(di->dev, "error reading current\n");
 		return 0;
 	}
-	ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
-	if (ret < 0) {
-		dev_err(di->dev, "error reading flags\n");
-		return 0;
-	}
-	if ((flags & (1 << 7)) != 0) {
-		dev_dbg(di->dev, "negative current!\n");
-		return -curr;
+
+	if (di->chip == BQ27500) {
+		/* bq27500 returns signed value */
+		curr = (int)(s16)curr;
+	} else {
+		ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
+		if (ret < 0) {
+			dev_err(di->dev, "error reading flags\n");
+			return 0;
+		}
+		if ((flags & (1 << 7)) != 0) {
+			dev_dbg(di->dev, "negative current!\n");
+			return -curr;
+		}
 	}
+
 	return curr;
 }
 
@@ -146,7 +162,10 @@ static int bq27x00_battery_rsoc(struct bq27x00_device_info *di)
 	int ret;
 	int rsoc = 0;
 
-	ret = bq27x00_read(BQ27x00_REG_RSOC, &rsoc, 1, di);
+	if (di->chip == BQ27500)
+		ret = bq27x00_read(BQ27500_REG_SOC, &rsoc, 0, di);
+	else
+		ret = bq27x00_read(BQ27000_REG_RSOC, &rsoc, 1, di);
 	if (ret) {
 		dev_err(di->dev, "error reading relative State-of-Charge\n");
 		return ret;
@@ -197,10 +216,10 @@ static void bq27x00_powersupply_init(struct bq27x00_device_info *di)
 }
 
 /*
- * BQ27200 specific code
+ * i2c specific code
  */
 
-static int bq27200_read(u8 reg, int *rt_value, int b_single,
+static int bq27x00_read_i2c(u8 reg, int *rt_value, int b_single,
 			struct bq27x00_device_info *di)
 {
 	struct i2c_client *client = di->client;
@@ -239,7 +258,7 @@ static int bq27200_read(u8 reg, int *rt_value, int b_single,
 	return err;
 }
 
-static int bq27200_battery_probe(struct i2c_client *client,
+static int bq27x00_battery_probe(struct i2c_client *client,
 				 const struct i2c_device_id *id)
 {
 	char *name;
@@ -258,7 +277,7 @@ static int bq27200_battery_probe(struct i2c_client *client,
 	if (retval < 0)
 		return retval;
 
-	name = kasprintf(GFP_KERNEL, "bq27200-%d", num);
+	name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 	if (!name) {
 		dev_err(&client->dev, "failed to allocate device name\n");
 		retval = -ENOMEM;
@@ -272,6 +291,7 @@ static int bq27200_battery_probe(struct i2c_client *client,
 		goto batt_failed_2;
 	}
 	di->id = num;
+	di->chip = id->driver_data;
 
 	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 	if (!bus) {
@@ -284,7 +304,7 @@ static int bq27200_battery_probe(struct i2c_client *client,
 	i2c_set_clientdata(client, di);
 	di->dev = &client->dev;
 	di->bat.name = name;
-	bus->read = &bq27200_read;
+	bus->read = &bq27x00_read_i2c;
 	di->bus = bus;
 	di->client = client;
 
@@ -314,7 +334,7 @@ static int bq27200_battery_probe(struct i2c_client *client,
 	return retval;
 }
 
-static int bq27200_battery_remove(struct i2c_client *client)
+static int bq27x00_battery_remove(struct i2c_client *client)
 {
 	struct bq27x00_device_info *di = i2c_get_clientdata(client);
 
@@ -335,27 +355,28 @@ static int bq27200_battery_remove(struct i2c_client *client)
  * Module stuff
  */
 
-static const struct i2c_device_id bq27200_id[] = {
-	{ "bq27200", 0 },
+static const struct i2c_device_id bq27x00_id[] = {
+	{ "bq27200", BQ27000 },	/* bq27200 is same as bq27000, but with i2c */
+	{ "bq27500", BQ27500 },
 	{},
 };
 
-static struct i2c_driver bq27200_battery_driver = {
+static struct i2c_driver bq27x00_battery_driver = {
 	.driver = {
-		.name = "bq27200-battery",
+		.name = "bq27x00-battery",
 	},
-	.probe = bq27200_battery_probe,
-	.remove = bq27200_battery_remove,
-	.id_table = bq27200_id,
+	.probe = bq27x00_battery_probe,
+	.remove = bq27x00_battery_remove,
+	.id_table = bq27x00_id,
 };
 
 static int __init bq27x00_battery_init(void)
 {
 	int ret;
 
-	ret = i2c_add_driver(&bq27200_battery_driver);
+	ret = i2c_add_driver(&bq27x00_battery_driver);
 	if (ret)
-		printk(KERN_ERR "Unable to register BQ27200 driver\n");
+		printk(KERN_ERR "Unable to register BQ27x00 driver\n");
 
 	return ret;
 }
@@ -363,7 +384,7 @@ module_init(bq27x00_battery_init);
 
 static void __exit bq27x00_battery_exit(void)
 {
-	i2c_del_driver(&bq27200_battery_driver);
+	i2c_del_driver(&bq27x00_battery_driver);
 }
 module_exit(bq27x00_battery_exit);