diff options
| -rw-r--r-- | drivers/hwmon/lm92.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/drivers/hwmon/lm92.c b/drivers/hwmon/lm92.c index 46579a3e1715..e2d8c8afcbfa 100644 --- a/drivers/hwmon/lm92.c +++ b/drivers/hwmon/lm92.c @@ -272,20 +272,28 @@ static int lm92_detect(struct i2c_client *new_client, struct i2c_board_info *info) { struct i2c_adapter *adapter = new_client->adapter; - u8 config; - u16 man_id; + u8 config_addr = LM92_REG_CONFIG; + u8 man_id_addr = LM92_REG_MAN_ID; + int i, regval; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; - config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG); - man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID); - - if ((config & 0xe0) == 0x00 && man_id == 0x0180) - pr_info("lm92: Found National Semiconductor LM92 chip\n"); - else - return -ENODEV; + /* + * Register values repeat with multiples of 8. + * Read twice to improve detection accuracy. + */ + for (i = 0; i < 2; i++) { + regval = i2c_smbus_read_word_data(new_client, man_id_addr); + if (regval != 0x0180) + return -ENODEV; + regval = i2c_smbus_read_byte_data(new_client, config_addr); + if (regval < 0 || (regval & 0xe0)) + return -ENODEV; + config_addr += 8; + man_id_addr += 8; + } strscpy(info->type, "lm92", I2C_NAME_SIZE); |