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 <tzungbi@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/max1619.c b/drivers/hwmon/max1619.c
index 72e17afb22f034fb1d3e5c6db57161d91d470c97..9b6d03cff4df5f2a197dd76c3173663aa3c9819a 100644 (file)
--- a/drivers/hwmon/max1619.c
+++ b/drivers/hwmon/max1619.c
@@ -260,31 +260,27 @@ static int max1619_detect(struct i2c_client *client,
                          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);