hwmon: (tmp421) Strengthen detect function
Not all supported chips support the entire I2C address range.
Only accept specific chips at the addresses supported by that chip.
Check for invalid values in conversion rate and status registers.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
diff --git a/Documentation/hwmon/tmp421 b/Documentation/hwmon/tmp421
index 0cf07f82..d0e7714 100644
--- a/Documentation/hwmon/tmp421
+++ b/Documentation/hwmon/tmp421
@@ -8,11 +8,11 @@
Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp421.html
* Texas Instruments TMP422
Prefix: 'tmp422'
- Addresses scanned: I2C 0x2a, 0x4c, 0x4d, 0x4e and 0x4f
+ Addresses scanned: I2C 0x4c, 0x4d, 0x4e and 0x4f
Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp421.html
* Texas Instruments TMP423
Prefix: 'tmp423'
- Addresses scanned: I2C 0x2a, 0x4c, 0x4d, 0x4e and 0x4f
+ Addresses scanned: I2C 0x4c and 0x4d
Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp421.html
Authors:
diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
index 7bab7a9..9438c1b 100644
--- a/drivers/hwmon/tmp421.c
+++ b/drivers/hwmon/tmp421.c
@@ -42,6 +42,7 @@
enum chips { tmp421, tmp422, tmp423 };
/* The TMP421 registers */
+#define TMP421_STATUS_REG 0x08
#define TMP421_CONFIG_REG_1 0x09
#define TMP421_CONVERSION_RATE_REG 0x0B
#define TMP421_MANUFACTURER_ID_REG 0xFE
@@ -235,6 +236,7 @@
enum chips kind;
struct i2c_adapter *adapter = client->adapter;
const char *names[] = { "TMP421", "TMP422", "TMP423" };
+ int addr = client->addr;
u8 reg;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
@@ -244,15 +246,27 @@
if (reg != TMP421_MANUFACTURER_ID)
return -ENODEV;
+ reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
+ if (reg & 0xf8)
+ return -ENODEV;
+
+ reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
+ if (reg & 0x7f)
+ return -ENODEV;
+
reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
switch (reg) {
case TMP421_DEVICE_ID:
kind = tmp421;
break;
case TMP422_DEVICE_ID:
+ if (addr == 0x2a)
+ return -ENODEV;
kind = tmp422;
break;
case TMP423_DEVICE_ID:
+ if (addr != 0x4c && addr != 0x4d)
+ return -ENODEV;
kind = tmp423;
break;
default: