On Sunday 21 of July 2013 16:37:33 Kishon Vijay Abraham I wrote: > Hi, > > On Sunday 21 July 2013 04:01 PM, Tomasz Figa wrote: > > Hi, > > > > On Saturday 20 of July 2013 19:59:10 Greg KH wrote: > >> On Sat, Jul 20, 2013 at 10:32:26PM -0400, Alan Stern wrote: > >>> On Sat, 20 Jul 2013, Greg KH wrote: > >>>>>>> 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. > >>>> > >>>> Why will you not have that pointer? You can't rely on the "name" > >>>> as > >>>> the device id will not match up, so you should be able to rely on > >>>> the pointer being in the structure that the board sets up, right? > >>>> > >>>> Don't use names, especially as ids can, and will, change, that is > >>>> going > >>>> to cause big problems. Use pointers, this is C, we are supposed to > >>>> be > >>>> doing that :) > >>> > >>> Kishon, I think what Greg means is this: The name you are using > >>> must > >>> be stored somewhere in a data structure constructed by the board > >>> file, > >>> right? Or at least, associated with some data structure somehow. > >>> Otherwise the platform code wouldn't know which PHY hardware > >>> corresponded to a particular name. > >>> > >>> Greg's suggestion is that you store the address of that data > >>> structure > >>> in the platform data instead of storing the name string. Have the > >>> consumer pass the data structure's address when it calls phy_create, > >>> instead of passing the name. Then you don't have to worry about two > >>> PHYs accidentally ending up with the same name or any other similar > >>> problems. > >> > >> Close, but the issue is that whatever returns from phy_create() > >> should > >> then be used, no need to call any "find" functions, as you can just > >> use > >> the pointer that phy_create() returns. Much like all other class api > >> functions in the kernel work. > > > > I think there is a confusion here about who registers the PHYs. > > > > All platform code does is registering a platform/i2c/whatever device, > > which causes a driver (located in drivers/phy/) to be instantiated. > > Such drivers call phy_create(), usually in their probe() callbacks, > > so platform_code has no way (and should have no way, for the sake of > > layering) to get what phy_create() returns. > > right. > > > IMHO we need a lookup method for PHYs, just like for clocks, > > regulators, PWMs or even i2c busses because there are complex cases > > when passing just a name using platform data will not work. I would > > second what Stephen said [1] and define a structure doing things in a > > DT-like way. > > > > Example; > > > > [platform code] > > > > static const struct phy_lookup my_phy_lookup[] = { > > > > PHY_LOOKUP("s3c-hsotg.0", "otg", "samsung-usbphy.1", "phy.2"), > > The only problem here is that if *PLATFORM_DEVID_AUTO* is used while > creating the device, the ids in the device name would change and > PHY_LOOKUP wont be useful.
I don't think this is a problem. All the existing lookup methods already use ID to identify devices (see regulators, clkdev, PWMs, i2c, ...). You can simply add a requirement that the ID must be assigned manually, without using PLATFORM_DEVID_AUTO to use PHY lookup. Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html