Re: [RFC PATCH V4 6/6] riscv: soc: Add Allwinner SoC kconfig option
From: Heinrich Schuchardt
Date: Tue Sep 14 2021 - 02:30:15 EST
On 9/14/21 7:16 AM, Samuel Holland wrote:
On 9/13/21 10:49 PM, Heinrich Schuchardt wrote:
Calling a Kconfig menu item "Allwinner SoCs" which includes all
future Allwinner SoCs irritates me. How about CONFIG_SOC_SUNXI_D1
instead?
Would you want to have a separate option for each new SoC? That seems
like the only way to split things up, if you want to be more specific
than than "sunxi" (or equivalently "sun20i", which is the codename for
the RISC-V series).
Except at the very beginning (sun4i-sun7i), there have not been clear
generational boundaries between the various sunxi SoCs, so most of the
32-bit ones already get lumped into a single symbol (MACH_SUN8I). And
there is a single Kconfig symbol, ARCH_SUNXI, for all 64-bit Allwinner SoCs.
On arm64 we have avoided SoC specific Kconfig symbols and left it to the
defconfig to select all SoC specific drivers. Generally the tendency of
the defconfigs is to provide a multiarch kernel. So this should be ok on
RISC-V too.
I was just concerned about the 8250 driver assigned to something called
"Allwinner SoCs" which didn't seem future proof.
There is enough overlap in peripherals that you need a common symbol for
the peripheral drivers anyway. How about... ARCH_SUNXI? There are 90+
uses of this symbol throughout drivers/ and sound/, and I have found
that more than half of them apply to the D1 (see e.g. this commit[1] and
some of its ancestors).
Looking at the current use of ARCH_SUNXI in drivers reusing the same
name on RISC-V makes sense.
Best regards
Heinrich
RISC-V has so far adopted a CONFIG_SOC_xxx naming scheme, which is
different from arm/arm64's CONFIG_ARCH_xxx pattern. But now we have a
case where a SoC family is split between the two architectures. I'm all
for consistency with the names of other RISC-V platform symbols, but it
seems that reusing the existing ARCH_SUNXI symbol would be better than
cluttering up the driver Kconfig files with a duplicate.
Regards,
Samuel
[1]: https://github.com/smaeul/linux/commit/7841e5c32366