@@ -332,26 +332,68 @@ 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);