Re: [PATCH] mfd: core: introduce of_node_name for mfd sub devices

[Lee Jones <lee.jones@linaro.org>]

On Thu, 19 Sep 2013, Mark Brown wrote:

> On Thu, Sep 19, 2013 at 09:30:50AM +0100, Lee Jones wrote:
> 
> > I'm not entirely sure this is what Mark was saying. I think he was
> > complaining about the existence of the sub-nodes rather than how the
> > MFD Core assigns their of_node. My take is that the chip is really a
> > single device which provides different bits of functionality. To break
> > that functionality up and disperse the drivers into various subsystems
> > is a Linuxisum. By providing each functional block with its own node
> > you're describing how we do things in Linux, rather than specifying a
> > single node for the AS3722 which would probably be the norm.
> 
> Yes, that's exactly what I was thinking of.
> 
> > Do the sub-nodes have their own properties? If so, it would be worth
> > breaking them up as other OSes could reuse the specifics. If they do,
> > then you need so put them in the binding. If they don't, then you do
> > not require sub-nodes. The MFD core will ensure the sub-devices are
> > probed and there is no requirement for the of_node to be assigned.
> 
> You do see some reusable IP blocks (like the regualtors on the wm831x
> PMICs for example, they're repeated blocks) which can be reused but
> generally they have a register base as part of the binding.  Personally
> if it's just a property or two I'd probably just put them on the root
> node for the device.

Agreed. Besides, there doesn't seem to be *any* sub-device properties
defined in the binding document. So what are you trying to achieve
with the child nodes?

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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