mfd: tps6586x: Add version detection

Use the VERSIONCRC to determine the exact device version. According to
the datasheet this register can be used as device identifier. The
identification is needed since some tps6586x regulators use a different
voltage table.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/tps6586x.c

@@ -124,6 +124,7 @@ struct tps6586x {
 	struct device		*dev;
 	struct i2c_client	*client;
 	struct regmap		*regmap;
+	int			version;
 
 	int			irq;
 	struct irq_chip		irq_chip;
@@ -208,6 +209,14 @@ int tps6586x_irq_get_virq(struct device *dev, int irq)
 }
 EXPORT_SYMBOL_GPL(tps6586x_irq_get_virq);
 
+int tps6586x_get_version(struct device *dev)
+{
+	struct tps6586x *tps6586x = dev_get_drvdata(dev);
+
+	return tps6586x->version;
+}
+EXPORT_SYMBOL_GPL(tps6586x_get_version);
+
 static int __remove_subdev(struct device *dev, void *unused)
 {
 	platform_device_unregister(to_platform_device(dev));
@@ -472,12 +481,38 @@ static void tps6586x_power_off(void)
 	tps6586x_set_bits(tps6586x_dev, TPS6586X_SUPPLYENE, SLEEP_MODE_BIT);
 }
 
+static void tps6586x_print_version(struct i2c_client *client, int version)
+{
+	const char *name;
+
+	switch (version) {
+	case TPS658621A:
+		name = "TPS658621A";
+		break;
+	case TPS658621CD:
+		name = "TPS658621C/D";
+		break;
+	case TPS658623:
+		name = "TPS658623";
+		break;
+	case TPS658643:
+		name = "TPS658643";
+		break;
+	default:
+		name = "TPS6586X";
+		break;
+	}
+
+	dev_info(&client->dev, "Found %s, VERSIONCRC is %02x\n", name, version);
+}
+
 static int tps6586x_i2c_probe(struct i2c_client *client,
 					const struct i2c_device_id *id)
 {
 	struct tps6586x_platform_data *pdata = dev_get_platdata(&client->dev);
 	struct tps6586x *tps6586x;
 	int ret;
+	int version;
 
 	if (!pdata && client->dev.of_node)
 		pdata = tps6586x_parse_dt(client);
@@ -487,19 +522,18 @@ static int tps6586x_i2c_probe(struct i2c_client *client,
 		return -ENOTSUPP;
 	}
 
-	ret = i2c_smbus_read_byte_data(client, TPS6586X_VERSIONCRC);
-	if (ret < 0) {
-		dev_err(&client->dev, "Chip ID read failed: %d\n", ret);
+	version = i2c_smbus_read_byte_data(client, TPS6586X_VERSIONCRC);
+	if (version < 0) {
+		dev_err(&client->dev, "Chip ID read failed: %d\n", version);
 		return -EIO;
 	}
 
-	dev_info(&client->dev, "VERSIONCRC is %02x\n", ret);
-
 	tps6586x = devm_kzalloc(&client->dev, sizeof(*tps6586x), GFP_KERNEL);
-	if (tps6586x == NULL) {
-		dev_err(&client->dev, "memory for tps6586x alloc failed\n");
+	if (!tps6586x)
 		return -ENOMEM;
-	}
+
+	tps6586x->version = version;
+	tps6586x_print_version(client, tps6586x->version);
 
 	tps6586x->client = client;
 	tps6586x->dev = &client->dev;

include/linux/mfd/tps6586x.h

@@ -13,6 +13,12 @@
 #define TPS6586X_SLEW_RATE_SET		0x08
 #define TPS6586X_SLEW_RATE_MASK         0x07
 
+/* VERSION CRC */
+#define TPS658621A	0x15
+#define TPS658621CD	0x2c
+#define TPS658623	0x1b
+#define TPS658643	0x03
+
 enum {
 	TPS6586X_ID_SYS,
 	TPS6586X_ID_SM_0,
@@ -97,5 +103,6 @@ extern int tps6586x_clr_bits(struct device *dev, int reg, uint8_t bit_mask);
 extern int tps6586x_update(struct device *dev, int reg, uint8_t val,
 			   uint8_t mask);
 extern int tps6586x_irq_get_virq(struct device *dev, int irq);
+extern int tps6586x_get_version(struct device *dev);
 
 #endif /*__LINUX_MFD_TPS6586X_H */