diff options
| -rw-r--r-- | drivers/hwmon/adm1021.c | 58 |
1 files changed, 50 insertions, 8 deletions
diff --git a/drivers/hwmon/adm1021.c b/drivers/hwmon/adm1021.c index 1ad0a885c5a..8178927d878 100644 --- a/drivers/hwmon/adm1021.c +++ b/drivers/hwmon/adm1021.c @@ -311,26 +311,68 @@ static int adm1021_detect(struct i2c_client *client, man_id = i2c_smbus_read_byte_data(client, ADM1021_REG_MAN_ID); dev_id = i2c_smbus_read_byte_data(client, ADM1021_REG_DEV_ID); + if (man_id < 0 || dev_id < 0) + return -ENODEV; + if (man_id == 0x4d && dev_id == 0x01) type_name = "max1617a"; else if (man_id == 0x41) { if ((dev_id & 0xF0) == 0x30) type_name = "adm1023"; - else + else if ((dev_id & 0xF0) == 0x00) type_name = "adm1021"; + else + return -ENODEV; } else if (man_id == 0x49) type_name = "thmc10"; else if (man_id == 0x23) type_name = "gl523sm"; else if (man_id == 0x54) type_name = "mc1066"; - /* LM84 Mfr ID in a different place, and it has more unused bits */ - else if (conv_rate == 0x00 - && (config & 0x7F) == 0x00 - && (status & 0xAB) == 0x00) - type_name = "lm84"; - else - type_name = "max1617"; + else { + int lte, rte, lhi, rhi, llo, rlo; + + /* extra checks for LM84 and MAX1617 to avoid misdetections */ + + llo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(0)); + rlo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(1)); + + /* fail if any of the additional register reads failed */ + if (llo < 0 || rlo < 0) + return -ENODEV; + + lte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(0)); + rte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(1)); + lhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(0)); + rhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(1)); + + /* + * Fail for negative temperatures and negative high limits. + * This check also catches read errors on the tested registers. + */ + if ((s8)lte < 0 || (s8)rte < 0 || (s8)lhi < 0 || (s8)rhi < 0) + return -ENODEV; + + /* fail if all registers hold the same value */ + if (lte == rte && lte == lhi && lte == rhi && lte == llo + && lte == rlo) + return -ENODEV; + + /* + * LM84 Mfr ID is in a different place, + * and it has more unused bits. + */ + if (conv_rate == 0x00 + && (config & 0x7F) == 0x00 + && (status & 0xAB) == 0x00) { + type_name = "lm84"; + } else { + /* fail if low limits are larger than high limits */ + if ((s8)llo > lhi || (s8)rlo > rhi) + return -ENODEV; + type_name = "max1617"; + } + } pr_debug("adm1021: Detected chip %s at adapter %d, address 0x%02x.\n", type_name, i2c_adapter_id(adapter), client->addr); |