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? -- RafaÅ _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
