2011/4/12 RafaÅ MiÅecki <zajec5@xxxxxxxxx>: > 2011/4/12 Hauke Mehrtens <hauke@xxxxxxxxxx>: >> Hi RafaÅ, >> >> On 04/12/2011 09:27 PM, RafaÅ MiÅecki wrote: >>> 2011/4/12 George Kashperko <george@xxxxxxxxxxx>: >>>> >>>>> 2011/4/12 George Kashperko <george@xxxxxxxxxxx>: >>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> On Tue, Apr 12, 2011 at 01:57:07AM +0200, RafaÅ MiÅecki wrote: >>>>>>>> Cc: Michael BÃsch <mb@xxxxxxxxx> >>>>>>>> Cc: Larry Finger <Larry.Finger@xxxxxxxxxxxx> >>>>>>>> Cc: George Kashperko <george@xxxxxxxxxxx> >>>>>>>> Cc: Arend van Spriel <arend@xxxxxxxxxxxx> >>>>>>>> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >>>>>>>> Cc: Russell King <rmk@xxxxxxxxxxxxxxxx> >>>>>>>> Cc: Arnd Bergmann <arnd@xxxxxxxx> >>>>>>>> Cc: Andy Botting <andy@xxxxxxxxxxxxxxx> >>>>>>>> Cc: linuxdriverproject <devel@xxxxxxxxxxxxxxxxxxxxxx> >>>>>>>> Cc: linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx> >>>>>>>> Signed-off-by: RafaÅ MiÅecki <zajec5@xxxxxxxxx> >>>>>>>> --- >>>>>>>> V2: Rename to axi >>>>>>>> Â Â Use DEFINE_PCI_DEVICE_TABLE in bridge >>>>>>>> Â Â Make use of pr_fmt and pr_* >>>>>>>> Â Â Store core class >>>>>>>> Â Â Rename bridge to not b43 specific >>>>>>>> Â Â Replace magic 0x1000 with BCMAI_CORE_SIZE >>>>>>>> Â Â Remove some old "ssb" names and defines >>>>>>>> Â Â Move BCMAI_ADDR_BASE def >>>>>>>> Â Â Add drvdata field >>>>>>>> V3: Fix reloading (kfree issue) >>>>>>>> Â Â Add 14e4:0x4331 >>>>>>>> Â Â Fix non-initialized struct issue >>>>>>>> Â Â Drop useless inline functions wrappers for pci core drv >>>>>>>> Â Â Proper pr_* usage >>>>>>>> V3.1: Include forgotten changes (pr_* and include related) >>>>>>>> Â Â Explain why we dare to implement empty release function >>>>>>> >>>>>>> I'm not sure we need this. If you have an IP Core which talks AXI and >>>>>>> you want to put it on a PCI bus, you will have a PCI Bus wrapper around >>>>>>> that IP Core, so you should go and let the kernel know about that. See >>>>>>> [1] for a core IP which talks AXI and [2] for a PCI bus glue layer. >>>>>>> >>>>>>> Besides, if you introduce this bus layer, it'll be more difficult for >>>>>>> other licensees of the same core to re-use the same driver, since it's >>>>>>> now talking a PCI emulated on top of AXI. The same can be achieved with >>>>>>> the platform_bus which is more widely used, specially on ARM SoCs. >>>>>>> >>>>>>> [1] http://gitorious.org/usb/usb/blobs/dwc3/drivers/usb/dwc3/core.c >>>>>>> [2] http://gitorious.org/usb/usb/blobs/dwc3/drivers/usb/dwc3/dwc3-haps.c >>>>>>> >>>>>> >>>>>> Already noticed earlier that AXI isnt really good name for >>>>>> Broadcom-specific axi bus customization. As of tech docs available from >>>>>> arm, corelink AXI cores use own identification registers which feature >>>>>> different format and layout comparing to that we use for Broadcom cores. >>>>>> >>>>>> Maybe there is something "standartized" by the DMP specs? If so I'm >>>>>> curious if that DMP is obligatory for every axi bus ? >>>>>> >>>>>> Naming particular Broadcom's implementation just axi limits other >>>>>> licensees in reusing axi bus name/code or will require hacks/workarounds >>>>>> from them to fit Broadcom-like core scanning/identificating techniques. >>>>>> You use bus named AXI to group and manage Broadcom cores, while never >>>>>> even publish device records for native axi cores Broadcom use to talk to >>>>>> the interconnect through. Yet again, something like bcmb/bcmai looks >>>>>> like better name for this bus. >>>>> >>>>> I don't know, I'm really tired of this. Earlier I was told to not use >>>>> anything like bcmai, because it is not Broadcom specific. Now it seems >>>>> (and I'm afraid I agree) there is quite a lot of Broadcom specific >>>>> stuff. >>>> Well, _if_ that "magic" EROM core layout is arm's "standard" for axi >>>> ports identification _and_ _if_ that EROM core is obligatory axi >>>> component then sure axi name is good one as soon as you consider >>>> registering master port (agent) cores with device subsystem as well. >>>> I have no clue here about how resolve those _if_'s, hopefully Broadcom >>>> guys can enlighten us on the subject. >>> >>> Do you think that in my code only scanning is Broadcom specific? In >>> such a case we could keep it "axi", and just s/scan/bcmscan/. This is >>> only correct choice if the rest (addressing, core enabling, host >>> management) is AXI specific. >> >> The specification for the AMBA AXI Interface is available for free >> download from ARM if you register to their website and accept their license: >> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.set.amba/index.html >> I got it from there without any problems and the license does not look >> too bad for me, by having a quick look at it. I do not know if it will >> help you in any way or if it is completely unrelated. >> >> Why is the existing support for the amba bus not extended or used in any >> way for this? It exists for some time in drivers/amba/. There already >> was a discussion about this in https://lkml.org/lkml/2011/3/30/186 , but >> with no result as I see. > > I can see exactly nothing I could use from whatever driver/amba is. > What does it do from things we need? How do you imagine using that > with out (non)Broadcom buses? 1) I checked for amba_device_register: http://lxr.free-electrons.com/ident?i=amba_device_register and do not understand that. There are a lot of drivers registering some pre-defined devices. I could not find any driver scanning for amba devices and registering them. Are we going to be the first driver registering devices dynamically or do I get this totally wrong 2) amba_id contains only some interesting "id". How can we relate this with our core id/rev/manuf/class? 3) There is no code for managing AMBA cores (enable, checking status, disabling, resetting)... That way I see really low (or not at all) relation between out (not)Broadcom bus and present AMBA bus. -- RafaÅ _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
