Re: [PATCH 00/12] Add minimal support for Exynos850 SoC

From: Sam Protsenko <semen.protsenko@linaro.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>,
	Chanwoo Choi <cw00.choi@samsung.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Tomasz Figa <tomasz.figa@gmail.com>,
	Rob Herring <robh+dt@kernel.org>, Stephen Boyd <sboyd@kernel.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Jiri Slaby <jirislaby@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Charles Keepax <ckeepax@opensource.wolfsonmicro.com>,
	Ryu Euiyoul <ryu.real@samsung.com>,
	Tom Gall <tom.gall@linaro.org>,
	Sumit Semwal <sumit.semwal@linaro.org>,
	John Stultz <john.stultz@linaro.org>,
	Amit Pundir <amit.pundir@linaro.org>,
	devicetree <devicetree@vger.kernel.org>,
	linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
	linux-clk <linux-clk@vger.kernel.org>,
	"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux Samsung SOC <linux-samsung-soc@vger.kernel.org>,
	"open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>
Subject: Re: [PATCH 00/12] Add minimal support for Exynos850 SoC
Date: Fri, 30 Jul 2021 22:02:12 +0300	[thread overview]
Message-ID: <CAPLW+4kbnJEBkc0D=RWt59JxBan8X1uDy6sSXBiYAq8N9FDV6A@mail.gmail.com> (raw)
In-Reply-To: <c3486111-0ec9-9679-d2a2-68b2f33a2450@canonical.com>

Hi Krzysztof,

On Fri, 30 Jul 2021 at 20:21, Krzysztof Kozlowski
<krzysztof.kozlowski@canonical.com> wrote:
>
> On 30/07/2021 17:18, Krzysztof Kozlowski wrote:
> > On 30/07/2021 16:49, Sam Protsenko wrote:
> >> This patch series adds initial platform support for Samsung Exynos850
> >> SoC [1]. With this patchset it's possible to run the kernel with BusyBox
> >> rootfs as a RAM disk. More advanced platform support (like MMC driver
> >> additions) will be added later. The idea is to keep the first submission
> >> minimal to ease the review, and then build up on top of that.
> >>
> >> [1] https://www.samsung.com/semiconductor/minisite/exynos/products/mobileprocessor/exynos-850/
> >>
> >
> > Great work!
> >

Thanks, Krzysztof! And thank you for reviewing the whole series.

> > What's the SoC revision number (should be accessible via
> > /sys/bus/soc/devices/soc0/)? Recent wrap in numbering of Exynos chips
> > might bring confusion...

# cat /sys/devices/soc0/revision
0

>
> Judging by vendor's sources it is quite confusing. It looks mostly like
> Exynos3830 but in few other cases it uses Exynos9 compatibles (Exynos9,
> Exynos9820). Only in few places there is Exynos850. Marketing department
> made it so confusing...  The revision embedded in SoC would be very
> interesting.
>

As I understand, this SoC is called Exynos850 everywhere now.
Exynos3830 is its old name, not used anymore. As you noticed from
patch #2, it shares some definitions with Exynos9 SoC, so I guess some
software is similar for both architectures. Not sure about hardware
though, never worked with Exynos9 CPUs. Anyway, I asked Samsung
representatives about naming, and it seems like we should stick to
"Exynos850" name, even in code.

> Anyway, judging by current versioning, there is a risk Samsung will come
> with a new chipset name conflicting with existing ones. It already
> overflowed.
>
> It's even worse with a thingy called "Exynos9 auto" which hides
> numbering even more.
>
>
> Best regards,
> Krzysztof