hwmon: (max1619) Improve chip detection code

Bail out immediately if reading any of the registers used for chip
detection fails, or if it returns an unexpected value. Drop all log
messages from detection code.

Reviewed-by: Tzung-Bi Shih <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/max1619.c

···
 			  struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = client->adapter;
-	u8 reg_config, reg_convrate, reg_status, man_id, chip_id;
+	int regval;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		return -ENODEV;
 
-	/* detection */
-	reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_CONFIG);
-	reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_CONVRATE);
-	reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_STATUS);
-	if ((reg_config & 0x03) != 0x00
-	 || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
-		dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
-			client->addr);
+	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONFIG);
+	if (regval < 0 || (regval & 0x03))
 		return -ENODEV;
-	}
+	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONVRATE);
+	if (regval < 0 || regval > 0x07)
+		return -ENODEV;
+	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_STATUS);
+	if (regval < 0 || (regval & 0x61))
+		return -ENODEV;
 
-	/* identification */
-	man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_MAN_ID);
-	chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_CHIP_ID);
-	if (man_id != 0x4D || chip_id != 0x04) {
-		dev_info(&adapter->dev,
-			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
-			 man_id, chip_id);
+	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_MAN_ID);
+	if (regval != 0x4d)
 		return -ENODEV;
-	}
+	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CHIP_ID);
+	if (regval != 0x04)
+		return -ENODEV;
 
 	strscpy(info->type, "max1619", I2C_NAME_SIZE);