[PATCH 1/3] hwmon: Driver for SMM665 Six-Channel Active DC Output Controller/Monitor
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From: Jean Delvare on 19 Jun 2010 04:30 On Fri, 18 Jun 2010 12:13:25 -0700, Guenter Roeck wrote: > On Fri, 2010-06-18 at 14:10 -0400, Jonathan Cameron wrote: > > Another quick query. Are the _min / _max attributes as defined in the > > abi meant for alarms? I always thought they were to tell userspace the > > limits on measurement? > > > Good question. I thought it is supposed to refer to alarm limits, but I > may be wrong. > > Browsing through a couple of drivers, it _looks_ like the values are > used for alarm limits (eg adm1025 or lm85). Limits are not always set to Yes, these are alarms. _min and _max are really misnomers, these should have been _low and _high but by the time I realized it, _min and _max were already de facto standards and it was too late to change this. Documentation/hwmon/sysfs-interface says: Usual items are "input" (measured value), "max" (high threshold, "min" (low threshold). Specific occurrences are then left without details. If you think this document can be improved, I welcome patches. > useful values, though. This is what my CPU board returns: > > lm85-i2c-0-2e > Adapter: SMBus PIIX4 adapter at 0580 > V1.5: +1.80 V (min = +0.00 V, max = +3.32 V) > VCore: +1.29 V (min = +0.00 V, max = +2.99 V) > V3.3: +3.32 V (min = +0.00 V, max = +4.38 V) > V5: +5.00 V (min = +0.00 V, max = +6.64 V) > V12: +12.12 V (min = +0.00 V, max = +15.94 V) > > The lm85 datasheet says: "If a voltage input either exceeds the value > set in the voltage high limit register or falls below the value set in > the voltage low limit register, the corresponding bit will be set > automatically by the LM85 in the interrupt status registers (41-42h)." > > > Either way, one of us has misunderstood so perhaps the documentation needs > > to be more specific.... > > Agreed. -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Jonathan Cameron on 19 Jun 2010 06:20
On 06/19/10 09:27, Jean Delvare wrote: > On Fri, 18 Jun 2010 12:13:25 -0700, Guenter Roeck wrote: >> On Fri, 2010-06-18 at 14:10 -0400, Jonathan Cameron wrote: >>> Another quick query. Are the _min / _max attributes as defined in the >>> abi meant for alarms? I always thought they were to tell userspace the >>> limits on measurement? >>> >> Good question. I thought it is supposed to refer to alarm limits, but I >> may be wrong. >> >> Browsing through a couple of drivers, it _looks_ like the values are >> used for alarm limits (eg adm1025 or lm85). Limits are not always set to > > Yes, these are alarms. _min and _max are really misnomers, these should > have been _low and _high but by the time I realized it, _min and _max > were already de facto standards and it was too late to change this. > > Documentation/hwmon/sysfs-interface says: > > Usual items are "input" (measured value), "max" (high threshold, > "min" (low threshold). Ah, I missed that general defining of terms. It's fine as is unless we end up with lots of people not reading it properly like me ;) > > Specific occurrences are then left without details. If you think this > document can be improved, I welcome patches. > >> useful values, though. This is what my CPU board returns: >> >> lm85-i2c-0-2e >> Adapter: SMBus PIIX4 adapter at 0580 >> V1.5: +1.80 V (min = +0.00 V, max = +3.32 V) >> VCore: +1.29 V (min = +0.00 V, max = +2.99 V) >> V3.3: +3.32 V (min = +0.00 V, max = +4.38 V) >> V5: +5.00 V (min = +0.00 V, max = +6.64 V) >> V12: +12.12 V (min = +0.00 V, max = +15.94 V) >> >> The lm85 datasheet says: "If a voltage input either exceeds the value >> set in the voltage high limit register or falls below the value set in >> the voltage low limit register, the corresponding bit will be set >> automatically by the LM85 in the interrupt status registers (41-42h)." >> >>> Either way, one of us has misunderstood so perhaps the documentation needs >>> to be more specific.... >> >> Agreed. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |