How do you link a device to a custom sysfs class? - linux

Question

I'm writing drivers for several pieces of custom hardware. All of the devices are attached via PCIe to a host computer. For convenience I would like to group all of these custom devices together into a sysfs class (which I believe is an acceptable thing to do?). Unfortunately the information in LDD3 is way out of date and I'm having trouble finding current documentation that discusses what I'm attempting to do.
Creating my custom class is easy enough:
struct class MY_CLASS = class_create(THIS_MODULE, "myclass")
And inside of my probe calls I've got access to the struct dev:
static int probe(struct pci_dev *pcidev, const struct pci_device_id *id)
{
...
struct dev *my_dev = &pcidev->dev;
...
}
My question is this: now that I've got the class and the dev, how do I create a link between the two?
The device_create() basically does what I want, but since I've already got a struct dev my understanding is that I shouldn't call device_create (i.e. create a new device) again.
I've done a little more tracing and found that device_add() which is called by device_create(), calls device_add_class_symlinks() (not exported unfortunately) which does something like this:
...
sysfs_create_link(&dev->class->p->subsys.kobj,&dev->kobj, dev_name(dev));
...
I tried something like this directly in my drivers to create the links I want but I can't get it to compile because struct subsys_private (the "p" member in the class struct) is not exposed anywhere?
Any help is greatly appreciated!

Answer 1

Are your drivers sitting on the specific bus? If no, what purpose of the specific class?
Anyway, for starter
struct class devclass = {…}
probe()
{
struct device *dev = …
dev->class = &devclass;
}
init()
{
class_register(&devclass);
}

Answer 2

I've encountered the same issue.
if i called device_register with my class pointer assigned to the device class member. it will create a subsystem in my device directory, which is what device_add_class_symlinks do. but in my device directory there is already subsystem directory which is the link to the bus my device is attached to.
don't know if you got a method