Jean Delvare wrote:
>> So the next challenge is temperature tracking. I understand that this
>> is not currently implemented by the driver (I'm looking at the 2.6.21
>> source; please let me know and accept my apologies if this driver has
>> been updated since then). I could perhaps add this functionality, but
>> first I'd like to know if there was some problem that prevented the
>> original author from doing so.
>
> This is still not implemented. The reason was a mix of lack of time and
> lack of interest. My CPU fan is pretty silent anyway, so I could live
> with it at full speed all the time. However, if you want to implement
> this feature, this is welcome, and I'll be happy to review and test
> your patch. This is probably the last missing feature in this driver
> for the F71805F. (For the F71872F, VID support is also missing.)
This doesn't fit in very well with the scheme described in Documentation/hwmon/sysfs-interface:
<quote>
pwm[1-*]_auto_channels_temp
Select which temperature channels affect this PWM
output in
auto mode. Bitfield, 1 is temp1, 2 is temp2, 4 is temp3 etc...
Which values are possible depend on the chip used.
RW
pwm[1-*]_auto_point[1-*]_pwm
pwm[1-*]_auto_point[1-*]_temp
pwm[1-*]_auto_point[1-*]_temp_hyst
Define the PWM vs temperature curve. Number of trip
points is
chip-dependent. Use this for chips which associate trip points
to PWM output channels.
RW
OR
temp[1-*]_auto_point[1-*]_pwm
temp[1-*]_auto_point[1-*]_temp
temp[1-*]_auto_point[1-*]_temp_hyst
Define the PWM vs temperature curve. Number of trip
points is
chip-dependent. Use this for chips which associate trip points
to temperature channels.
RW
</quote>
In contrast to that framework,
1. This chip ties pwm<n>, fan<n> and temp<n> together, so the
'channels' idea doesn't apply.
2. The points relate fan speeds and temperatures, not pwm values and temperatures.
3. It doesn't have variable hysteresis.
It defines a temp/speed staircase with three (temp,speed) pairs:
- When temp<temp1, fan is off.
- When temp1<temp<temp2, fan adjusts to make speed=speed1.
- When temp2<temp<temp3, fan adjusts to make speed=speed2.
- When temp3<temp, fan adjusts to make speed=speed3.
..except that actually it interpolates an additional two pairs between
the ones that you define.
So, I propose the following sysfs files:
for n in 1 2 3
for p in 1 2 3
pwm$n_auto_point$p_temp
pwm$n_auto_point$p_fan
but I'm open to alternative ideas.
So I believe that I need to:
- Create the sysfs stuff.
- Extend the mode-change stuff to adjust file permissions appropriately.
- Add show/set functions that access the device registers.
and that's about it. What have I forgotten?
Regards,
Phil.
