[PATCH RESEND 1/3] arm64: add THUNDER2 processor family

[Arnd Bergmann]

On Mon, Feb 6, 2017 at 4:21 PM, Jayachandran C <jnair at caviumnetworks.com> wrote:
> On Mon, Feb 06, 2017 at 02:44:13PM +0100, Arnd Bergmann wrote:
>> On Mon, Feb 6, 2017 at 11:06 AM, Will Deacon <will.deacon at arm.com> wrote:
>
> The Vulcan architecture has been discontinued by Broadcom, so the platform
> and device tree files should go away soon. Renames are going to be messy, it
> will be better to keep Vulcan around until the transition is complete, and
> then delete it.

What are the disadvantages of a rename in your opinion? Are you mainly
worried about merge conflicts or something else?

>> Hmm, an alternative would be to add the new .dtsi file and start out with an
>> #include of the existing file, with overrides for anything that needs changing.
>> Similarly, the Kconfig symbol could just 'select ARCH_VULCAN' for now.
>
> Even in this case, we will need to copy the files from boot/dts/broadcom to
> boot/dts/cavium along the way. The current patchset is (in my opinion) the
> least messy way to accomplish the transition. But it is the maintainer's call,
> so if you think it has to be done differently, I can update the patchset and
> post again.

I don't see the need to copy if we can do an #include and later move the
file into the new place. I also see only three references to ARCH_VULCAN
at all aside from the dts file.

arch/arm64/configs/defconfig:CONFIG_ARCH_VULCAN=y
drivers/gpio/Kconfig:   depends on OF_GPIO && (CPU_XLP || ARCH_VULCAN
|| COMPILE_TEST)
drivers/i2c/busses/Kconfig:     depends on CPU_XLP || ARCH_VULCAN ||
COMPILE_TEST
drivers/spi/Kconfig:    depends on CPU_XLP || ARCH_VULCAN || COMPILE_TEST

We can probably manage to have a single patch to rename them all at
the same time, or we do the add+remove over two merge windows.

I also noticed now that you dropped the vulcan "compatible" strings in
the .dtsi files, I think we should keep those as a fallback, and to avoid
having interdependencies with the driver updates, e.g. the top-level
compatible string should be

compatible = "cavium,thunder-9900", "brcm,vulcan-soc";

for the SoC, plus of course the board specific identifier in front of that.
Same for the CPU, the i2c, gpio, and pmu.

    Arnd