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| author | Eric Miao <eric.y.miao@gmail.com> | 2012-01-16 22:51:45 +0100 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2012-01-16 22:51:45 +0100 |
| commit | 012f3b9118c7aaa3549f89299386f92b6580d235 (patch) | |
| tree | 7ee22ace6e9446c699ffa2451e03225bddc80590 /drivers/hwmon/max1111.c | |
| parent | 53999bf34d55981328f8ba9def558d3e104d6e36 (diff) | |
| download | lwn-012f3b9118c7aaa3549f89299386f92b6580d235.tar.gz lwn-012f3b9118c7aaa3549f89299386f92b6580d235.zip | |
hwmon: (max1111) Change sysfs interface to in[0-3]_input in millivolts
This patch fixed the inconsistent max1111 sysfs interface as pointed
out by Jean Delvare:
It was pointed to me that the max1111 driver doesn't implement the
standard sysfs interface for hwmon drivers (as described in
Documentation/hwmon/sysfs-interface). It exports files adc[0-3]_in,
which
aren't part of the standard interface. Presumably these should be
renamed to in[0-3]_input. Renaming them is probably not sufficient
though, as I see no scaling done in the driver. As the MAX1111 chip has
a documented full scale of 2.048V, I take it that the LSB of the ADC
has a weight of 8 mV. Exporting raw register values to user-space is
not OK.
Reported-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/hwmon/max1111.c')
| -rw-r--r-- | drivers/hwmon/max1111.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/hwmon/max1111.c b/drivers/hwmon/max1111.c index 84ef3a898707..482ca901db30 100644 --- a/drivers/hwmon/max1111.c +++ b/drivers/hwmon/max1111.c @@ -106,11 +106,14 @@ static ssize_t show_adc(struct device *dev, if (ret < 0) return ret; - return sprintf(buf, "%d\n", ret); + /* assume the reference voltage to be 2.048V, with an 8-bit sample, + * the LSB weight is 8mV + */ + return sprintf(buf, "%d\n", ret * 8); } #define MAX1111_ADC_ATTR(_id) \ - SENSOR_DEVICE_ATTR(adc##_id##_in, S_IRUGO, show_adc, NULL, _id) + SENSOR_DEVICE_ATTR(in##_id##_input, S_IRUGO, show_adc, NULL, _id) static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); static MAX1111_ADC_ATTR(0); @@ -120,10 +123,10 @@ static MAX1111_ADC_ATTR(3); static struct attribute *max1111_attributes[] = { &dev_attr_name.attr, - &sensor_dev_attr_adc0_in.dev_attr.attr, - &sensor_dev_attr_adc1_in.dev_attr.attr, - &sensor_dev_attr_adc2_in.dev_attr.attr, - &sensor_dev_attr_adc3_in.dev_attr.attr, + &sensor_dev_attr_in0_input.dev_attr.attr, + &sensor_dev_attr_in1_input.dev_attr.attr, + &sensor_dev_attr_in2_input.dev_attr.attr, + &sensor_dev_attr_in3_input.dev_attr.attr, NULL, }; |