Re: [PATCH] Add sysfs support to the IPMI driver

[Corey Minyard <minyard@acm.org>]

Greg KH wrote:

>On Sat, Mar 12, 2005 at 10:57:24PM -0600, Corey Minyard wrote:
>  
>
>>The IPMI driver has long needed to tie into the device model (and I've 
>>long been hoping someone else would do it).  I finally gave up and spent 
>>the time to learn how to do it.  I think this is right, it seems to work 
>>on on my system.
>>    
>>
>
>Looks good.  One minor question:
>
>  
>
>>+
>>+	snprintf(name, sizeof(name), "ipmi%d", if_num);
>>+	class_simple_device_add(ipmi_class, dev, NULL, name);
>>    
>>
>
>What do ipmi class devices live on?  pci devices?  i2c devices?
>platform devices?  Or are they purely virtual things?
>  
>
Good question.  I struggled with this for a little while and decided the 
class interface was important to have in first and I'd figure out the 
rest later.  They live in different places depending on the particular 
low-level interface.  Some live on the I2C bus (and will show up there 
in sysfs with the I2C driver).  Some live on the ISA bus, some are 
memory-mapped, some are on the PCI bus (though there is not a driver for 
PCI support yet), and some sit on the end of a serial port (driver is in 
the works).  I know, it's a mess, but there's not much I can do about 
these crazy hardware manufacturers.

I wasn't sure where to handle all this.  The I2C and PCI bus side of 
things should be handled.  However, the others probably need to sit 
someplace on a bus, right?  That should probably be handled in the 
low-level code that actually knows where the hardware sits.

Thanks,

-Corey