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    SubjectRe: [PATCH 01/15] drivers: phy: add generic PHY framework
    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.
    >
    > Do you have any drivers that are non-dt using this yet?

    yes. tw4030 (used in OMAP3) supports non-dt.
    [PATCH 04/15] ARM: OMAP: USB: Add phy binding information
    [PATCH 06/15] usb: musb: omap2430: use the new generic PHY framework
    of this patch series shows how it's used.

    Thanks
    Kishon


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