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| author | Guenter Roeck <guenter.roeck@ericsson.com> | 2011-06-30 02:09:37 -0700 |
|---|---|---|
| committer | Guenter Roeck <guenter.roeck@ericsson.com> | 2011-07-10 08:54:15 -0700 |
| commit | 0c2a40e2fe4f4af0410f57e84b95b817ec15aa70 (patch) | |
| tree | ca3d7268acc38bf2549dc53be8c96df98560cfd4 /drivers/hwmon/lm95241.c | |
| parent | 27739e694a3c34b5e371575d74e500d60111c689 (diff) | |
| download | lwn-0c2a40e2fe4f4af0410f57e84b95b817ec15aa70.tar.gz lwn-0c2a40e2fe4f4af0410f57e84b95b817ec15aa70.zip | |
hwmon: (lm95241) Fix negative temperature results
Negative temperatures were returned in degrees C instead of milli-Degrees C.
Also, negative temperatures were reported for remote temperature sensors even
if the chip was configured for positive-only results.
Fix by detecting temperature modes, and by treating negative temperatures
similar to positive temperatures, with appropriate sign extension.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org # 2.6.30+
Diffstat (limited to 'drivers/hwmon/lm95241.c')
| -rw-r--r-- | drivers/hwmon/lm95241.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/hwmon/lm95241.c b/drivers/hwmon/lm95241.c index 01c638e31e07..d3b464b74ced 100644 --- a/drivers/hwmon/lm95241.c +++ b/drivers/hwmon/lm95241.c @@ -98,11 +98,16 @@ struct lm95241_data { }; /* Conversions */ -static int TempFromReg(u8 val_h, u8 val_l) +static int temp_from_reg_signed(u8 val_h, u8 val_l) { - if (val_h & 0x80) - return val_h - 0x100; - return val_h * 1000 + val_l * 1000 / 256; + s16 val_hl = (val_h << 8) | val_l; + return val_hl * 1000 / 256; +} + +static int temp_from_reg_unsigned(u8 val_h, u8 val_l) +{ + u16 val_hl = (val_h << 8) | val_l; + return val_hl * 1000 / 256; } static struct lm95241_data *lm95241_update_device(struct device *dev) @@ -135,10 +140,13 @@ static ssize_t show_input(struct device *dev, struct device_attribute *attr, char *buf) { struct lm95241_data *data = lm95241_update_device(dev); + int index = to_sensor_dev_attr(attr)->index; return snprintf(buf, PAGE_SIZE - 1, "%d\n", - TempFromReg(data->temp[to_sensor_dev_attr(attr)->index], - data->temp[to_sensor_dev_attr(attr)->index + 1])); + index == 0 || (data->config & (1 << (index / 2))) ? + temp_from_reg_signed(data->temp[index], data->temp[index + 1]) : + temp_from_reg_unsigned(data->temp[index], + data->temp[index + 1])); } static ssize_t show_type(struct device *dev, struct device_attribute *attr, |