Re: [PATCH 01/15] drivers: phy: add generic PHY framework

[Kishon Vijay Abraham I]

Hi,

On Saturday 20 July 2013 05:20 AM, Greg KH wrote:
> On Fri, Jul 19, 2013 at 12:06:01PM +0530, Kishon Vijay Abraham I wrote:
> > Hi,
> >
> > On Friday 19 July 2013 11:59 AM, Greg KH wrote:
> > > On Fri, Jul 19, 2013 at 11:25:44AM +0530, Kishon Vijay Abraham I wrote:
> > > > Hi,
> > > >
> > > > On Friday 19 July 2013 11:13 AM, Greg KH wrote:
> > > > > On Fri, Jul 19, 2013 at 11:07:10AM +0530, Kishon Vijay Abraham I wrote:
> > > > > > > > > > +	ret = dev_set_name(&phy->dev, "%s.%d", dev_name(dev), id);
> > > > > > > > >
> > > > > > > > > Your naming is odd, no "phy" anywhere in it?  You rely on the sender to
> > > > > > > > > never send a duplicate name.id pair?  Why not create your own ids based
> > > > > > > > > on the number of phys in the system, like almost all other classes and
> > > > > > > > > subsystems do?
> > > > > > > >
> > > > > > > > hmm.. some PHY drivers use the id they provide to perform some of their
> > > > > > > > internal operation as in [1] (This is used only if a single PHY provider
> > > > > > > > implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO
> > > > > > > > to give the PHY drivers an option to use auto id.
> > > > > > > >
> > > > > > > > [1] ->
> > > > > > > > http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html
> > > > > > >
> > > > > > > No, who cares about the id?  No one outside of the phy core ever should,
> > > > > > > because you pass back the only pointer that they really do care about,
> > > > > > > if they need to do anything with the device.  Use that, and then you can
> > > > > >
> > > > > > hmm.. ok.
> > > > > >
> > > > > > > rip out all of the "search for a phy by a string" logic, as that's not
> > > > > >
> > > > > > Actually this is needed for non-dt boot case. In the case of dt boot, we use a
> > > > > > phandle by which the controller can get a reference to the phy. But in the case
> > > > > > of non-dt boot, the controller can get a reference to the phy only by label.
> > > > >
> > > > > I don't understand.  They registered the phy, and got back a pointer to
> > > > > it.  Why can't they save it in their local structure to use it again
> > > > > later if needed?  They should never have to "ask" for the device, as the
> > > >
> > > > One is a *PHY provider* driver which is a driver for some PHY device. This will
> > > > use phy_create to create the phy.
> > > > The other is a *PHY consumer* driver which might be any controller driver (can
> > > > be USB/SATA/PCIE). The PHY consumer will use phy_get to get a reference to the
> > > > phy (by *phandle* in the case of dt boot and *label* in the case of non-dt boot).
> > > > > device id might be unknown if there are multiple devices in the system.
> > > >
> > > > I agree with you on the device id part. That need not be known to the PHY driver.
> > >
> > > How does a consumer know which "label" to use in a non-dt system if
> > > there are multiple PHYs in the system?
> >
> > That should be passed using platform data.
>
> Ick, don't pass strings around, pass pointers.  If you have platform
> data you can get to, then put the pointer there, don't use a "name".

I don't think I understood you here :-s We wont have phy pointer when we 
create the device for the controller no?(it'll be done in board file). 
Probably I'm missing something.

Thanks
Kishon
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