Creation of driver-specific sysfs attributes

Creation of driver-specific sysfs attributes

[Marcelo Tosatti]

Hi Greg, others,

Hope this is not a FAQ.

I want to export some read-only attributes (statistics) from cyclades.c char 
driver to userspace via sysfs. 

I can't figure out the right place to do it - I could create a class under
/sys/class/cyclades for example, but that doesnt sound right since this 
is not a "class" of device, but a device itself.

Hooking the statistics into /sys/class/tty/ttyC$/ sounds reasonable, but
its not possible it seems because "tty" is a class_simple class, which only implements 
the "dev" attribute.

What is the appropriate place for such driver-specific attributes?

TIA

Re: Creation of driver-specific sysfs attributes

[Greg KH]

On Wed, Jul 07, 2004 at 12:21:06PM -0300, Marcelo Tosatti wrote:
> Hi Greg, others,
> 
> Hope this is not a FAQ.
> 
> I want to export some read-only attributes (statistics) from cyclades.c char 
> driver to userspace via sysfs. 
> 
> I can't figure out the right place to do it - I could create a class under
> /sys/class/cyclades for example, but that doesnt sound right since this 
> is not a "class" of device, but a device itself.

For a driver only attribute, you want them to show up in the place for
the driver (like under /sys/bus/pci/driver/MY_FOO_DRIVER/).  To do that
use the DRIVER_ATTR() and the driver_add_file() functions.  For
examples, see the other drivers that use these functions.

Hope this helps,

greg k-h