Skip to content

Commit

Permalink
hwmon: (max1111) Change sysfs interface to in[0-3]_input in millivolts
Browse files Browse the repository at this point in the history
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>
  • Loading branch information
Eric Miao authored and Jean Delvare committed Jan 16, 2012
1 parent 53999bf commit 012f3b9
Showing 1 changed file with 9 additions and 6 deletions.
15 changes: 9 additions & 6 deletions drivers/hwmon/max1111.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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,
};

Expand Down

0 comments on commit 012f3b9

Please sign in to comment.