kobj should not mention 'softc', it is not limited to the driver support. It should be named more generally.

So what does this method have over the existing practice of having the base-class' softc be the first element of the softc for derived classes?

In D59115#1355807, @kib wrote:

kobj should not mention 'softc', it is not limited to the driver support. It should be named more generally.

Completely agree, but despite my best efforts, I can't figure out which word to use instead of “softc”

In D59115#1356419, @imp wrote:

So what does this method have over the existing practice of having the base-class' softc be the first element of the softc for derived classes?

Using the base class's softc as the first element of the softc for the derived class only works in a single-inheritance cases.
However, with "modern" DT, final drivers should be composed of multiple functions. Typically, but not exclusively, the final driver is a combination of a 'real function' driver, syscon and simplebus. This is impossible with the current machinery.

Another example is the clock driver group. Currently, we have base clock classes for the divider, the multiplexer and the gate. However, we also need a class that combines these three functions into one complex clock class.

In D59115#1356428, @mmel wrote:

In D59115#1355807, @kib wrote:

kobj should not mention 'softc', it is not limited to the driver support. It should be named more generally.

Completely agree, but despite my best efforts, I can't figure out which word to use instead of “softc”

May be loan the terminology directly from the OOP crowd, like 'base class', and 'subclass'?

This is one of my dilemmas. KOBJ consistently uses 'baseclass', but 'kobj_offsetof_baseclass' or 'kobj_baseclass_offsetof' looks ugly, especially since these could also be used for the main/leaf class.

What about 'kobj_offsetof_class' and 'kobj_sizeof_class'?

In D59115#1356439, @mmel wrote:

This is one of my dilemmas. KOBJ consistently uses 'baseclass', but 'kobj_offsetof_baseclass' or 'kobj_baseclass_offsetof' looks ugly, especially since these could also be used for the main/leaf class.

What about 'kobj_offsetof_class' and 'kobj_sizeof_class'?

It is probably not class, but class data, am I right? Then might be kobj_instance_data_offset and kobj_total_data_size would be good?

kobj_total_data_size looks good — thanks!
kobj_instance_data_offset seems too long to me, and 'instance' is not entirely precise. Can we shorten it to kobj_data_offset?

In D59115#1356589, @mmel wrote:

kobj_total_data_size looks good — thanks!
kobj_instance_data_offset seems too long to me, and 'instance' is not entirely precise. Can we shorten it to kobj_data_offset?

I would prefer than to use kobj_instance_offset instead.

I'm also fine with it, thanks. Is the device_get_softc_class() function OK? That's actually the one I had the most trouble with.

In D59115#1357897, @mmel wrote:

I'm also fine with it, thanks. Is the device_get_softc_class() function OK? That's actually the one I had the most trouble with.

Do you mean 'the name for device_get_softc_class()'? IMO yes, because the function operates on softc.