Re: Question: hwmon: Adding addtitional sysfs entries

[Andreas Werner <wernerandy@gmx.de>]

On Sat, May 10, 2014 at 05:32:13AM -0700, Guenter Roeck wrote:
> On 05/10/2014 06:22 AM, Andreas Werner wrote:
> >Hi,
> >i am currently working on an implemenation of my Board Management Controller (BMC).
> >
> >This Controller is a MCR assembled on almost all of our Compact PCI or Compact PCI Serial
> >Cards as well as on some other CPU Boards.
> >
> >The BMC includes LED´s, Watchdog, Voltage Monitoring and some other features.
> >I have already implemented an MFD driver, LED and Watchdog driver.
> >
> >Currently i am working on the hwmon implemenation. This includes for the first step the
> >voltage monitoring.
> >
> >The BMC has some other feature which are not supported by any of the subsystem.
> >  - Errorcounter (Board status)
> >  - Power Failure status
> >  - Operating ours
> 
> Guess you mean hours here.

Yes sorry my mistake.

> 
> >  - Do software reset, do cold reset
> >  - Set power modes
> >  - Backplate Geographical Address
> >
> >These are all informations related to the Board where the BMC is assembled to.
> >I think all those features could be part of the hwmon implementation.
> >
> Why ?

As all of the settings are CPU board related i thought it will be an good idea
to put as much settings as possible to a group to one subsystem.
This would be easier for the User Application.

> 
> >Is it possible to add "custom" sysfs entries in my hwmon driver to support all these features?
> >Does lm-sensor ingore those custom features or is it a problem for lm-sensors?
> >
> >What is the normal way to add those features?
> >
> 
> The hwmon subsystem isn't really the correct location for this functionality.
> Power management should be done with a regulator driver (possibly power).
> The other attributes and functionality would better fit into the mfd core
> driver.
> 

MFD Core sounds good. That is also perfect for the User App. 

> You might want to tie the reset functions into the system reset functionality.

I do not understand this. Is there another subsystem or something like that
were I can put the Reset stuff to?

> 
> Guenter
> 


I guess the hwmon subsys is the right place for the voltage monitoring (3,3V, 5V etc) isn´t it?


Regards Andy