redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

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>
hifive-unleashed-5.1
Guenter Roeck 2014-04-22 16:13:17 -07:00
parent e47c39b3a8
commit a63ee9d83b
2 changed files with 16 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Documentation/hwmon/tmp421
View File

@ -8,11 +8,11 @@ Supported chips:
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:

14
drivers/hwmon/tmp421.c
View File

@ -42,6 +42,7 @@ static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
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 @@ static int tmp421_detect(struct i2c_client *client,
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 @@ static int tmp421_detect(struct i2c_client *client,
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: