[PATCH v2 1/3] mfd: tps6586x: add version detection

[Stefan Agner <stefan@agner.ch>]

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>
---
 drivers/mfd/tps6586x.c       | 47 +++++++++++++++++++++++++++++++++++++-------
 include/linux/mfd/tps6586x.h |  7 +++++++
 2 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/drivers/mfd/tps6586x.c b/drivers/mfd/tps6586x.c
index ee61fd7..8fc5a68 100644
--- a/drivers/mfd/tps6586x.c
+++ b/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));
@@ -472,6 +481,31 @@ 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)
 {
@@ -487,19 +521,18 @@ static int tps6586x_i2c_probe(struct i2c_client *client,
 		return -ENOTSUPP;
 	}
 
+	tps6586x = devm_kzalloc(&client->dev, sizeof(*tps6586x), GFP_KERNEL);
+	if (!tps6586x)
+		return -ENOMEM;
+
 	ret = i2c_smbus_read_byte_data(client, TPS6586X_VERSIONCRC);
 	if (ret < 0) {
 		dev_err(&client->dev, "Chip ID read failed: %d\n", ret);
 		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");
-		return -ENOMEM;
-	}
+	tps6586x->version = ret;
+	tps6586x_print_version(client, tps6586x->version);
 
 	tps6586x->client = client;
 	tps6586x->dev = &client->dev;
diff --git a/include/linux/mfd/tps6586x.h b/include/linux/mfd/tps6586x.h
index 8799454..cbecec2 100644
--- a/include/linux/mfd/tps6586x.h
+++ b/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 */
-- 
1.8.4.2