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

Corey Minyard
2005-03-13T22:59:22Z

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