Messages in this thread |  | | Date | Tue, 4 Oct 2016 15:16:55 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCHv2] hwmon: adm9240: handle temperature readings below 0 |
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On Wed, Oct 05, 2016 at 10:40:54AM +1300, Chris Packham wrote: > Unlike the temperature thresholds the temperature data is a 9-bit signed > value. This allows and additional 0.5 degrees of precision on the > reading but makes handling negative values slightly harder. In order to > have sign-extension applied correctly the 9-bit value is stored in the > upper bits of a signed 16-bit value. When presenting this in sysfs the > value is shifted and scaled appropriately. > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Applied (after removing the extra () in the data->temp assignment).
Thanks, Guenter
> --- > Changes in v2: > - Simplify as per feedback from Guenter. > - Re-word commit message. > > drivers/hwmon/adm9240.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwmon/adm9240.c b/drivers/hwmon/adm9240.c > index 98114ce..8d8ede8 100644 > --- a/drivers/hwmon/adm9240.c > +++ b/drivers/hwmon/adm9240.c > @@ -197,7 +197,7 @@ static struct adm9240_data *adm9240_update_device(struct device *dev) > data->temp = ((i2c_smbus_read_byte_data(client, > ADM9240_REG_TEMP) << 8) | > i2c_smbus_read_byte_data(client, > - ADM9240_REG_TEMP_CONF)) / 128; > + ADM9240_REG_TEMP_CONF)); > > for (i = 0; i < 2; i++) { /* read fans */ > data->fan[i] = i2c_smbus_read_byte_data(client, > @@ -263,7 +263,7 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *dummy, > char *buf) > { > struct adm9240_data *data = adm9240_update_device(dev); > - return sprintf(buf, "%d\n", data->temp * 500); /* 9-bit value */ > + return sprintf(buf, "%d\n", data->temp / 128 * 500); /* 9-bit value */ > } > > static ssize_t show_max(struct device *dev, struct device_attribute *devattr, > -- > 2.10.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
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