Re: [PATCH 05/12] riscv: Add the Allwinner SoC family Kconfig option

From: "Heiko Stübner" <heiko@sntech.de>
To: samuel@sholland.org, wens@csie.org, jernej.skrabec@gmail.com,
	linux-sunxi@lists.linux.dev, palmer@dabbelt.com,
	paul.walmsley@sifive.com, aou@eecs.berkeley.edu,
	linux-riscv@lists.infradead.org
Cc: robh+dt@kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, krzysztof.kozlowski+dt@linaro.org,
	Conor.Dooley@microchip.com
Subject: Re: [PATCH 05/12] riscv: Add the Allwinner SoC family Kconfig option
Date: Tue, 16 Aug 2022 11:17:22 +0200	[thread overview]
Message-ID: <10785313.BaYr0rKQ5T@diego> (raw)
In-Reply-To: <a70e34b9-7106-ad2a-16e1-5f115e34ff1e@microchip.com>

Am Montag, 15. August 2022, 18:56:23 CEST schrieb Conor.Dooley@microchip.com:
> On 15/08/2022 06:08, Samuel Holland wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> > 
> > Allwinner manufactures the sunxi family of application processors. This
> > includes the "sun8i" series of ARMv7 SoCs, the "sun50i" series of ARMv8
> > SoCs, and now the "sun20i" series of 64-bit RISC-V SoCs.
> > 
> > The first SoC in the sun20i series is D1, containing a single T-HEAD
> > C906 core. D1s is a low-pin-count variant of D1 with co-packaged DRAM.
> > 
> > Most peripherals are shared across the entire chip family. In fact, the
> > ARMv7 T113 SoC is pin-compatible and almost entirely register-compatible
> > with the D1s.
> > 
> > This means many existing device drivers can be reused. To facilitate
> > this reuse, name the symbol ARCH_SUNXI, since that is what the existing
> > drivers have as their dependency.
> 
> Hey Samuel,
> I think this and patch 12/12 with the defconfig changes should be
> deferred until post LPC (which still leaves plenty of time for
> making the 6.1 merge window). We already have like 4 different
> approaches between the existing SOC_FOO symbols & two more when
> D1 stuff and the Renesas stuff is considered.

On the other hand, I don't really think it's that hard to change things
after the fact? I.e. ARCH_SUNXI is pretty much set in stone anyway,
so there isn't very much that _could_ change without affecting most
driver subsystems in the kernel.

So I don't think we'd actually need to wait with the Allwinner symbol.

Heiko

> Plan is to decide at LPC on one approach for what to do with
> Kconfig.socs & to me it seems like a good idea to do what's being
> done here - it's likely that further arm vendors will move and
> keeping the common symbols makes a lot of sense to me...
> 
> Thanks,
> Conor.
> 
> > 
> > Signed-off-by: Samuel Holland <samuel@sholland.org>
> > ---
> > 
> >  arch/riscv/Kconfig.socs | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs
> > index 69774bb362d6..1caacbfac1a5 100644
> > --- a/arch/riscv/Kconfig.socs
> > +++ b/arch/riscv/Kconfig.socs
> > @@ -1,5 +1,14 @@
> >  menu "SoC selection"
> > 
> > +config ARCH_SUNXI
> > +       bool "Allwinner sun20i SoCs"
> > +       select ERRATA_THEAD if MMU && !XIP_KERNEL
> > +       select SIFIVE_PLIC
> > +       select SUN4I_TIMER
> > +       help
> > +         This enables support for Allwinner sun20i platform hardware,
> > +         including boards based on the D1 and D1s SoCs.
> > +
> >  config SOC_MICROCHIP_POLARFIRE
> >         bool "Microchip PolarFire SoCs"
> >         select MCHP_CLK_MPFS
> > --
> > 2.35.1
> > 
> 
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