From: Sam Protsenko <semen.protsenko@linaro.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
Alim Akhtar <alim.akhtar@samsung.com>,
Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Tomasz Figa <tomasz.figa@gmail.com>,
linux-samsung-soc@vger.kernel.org, linux-clk@vger.kernel.org,
devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 11/16] clk: samsung: Keep register offsets in chip specific structure
Date: Sat, 24 Feb 2024 13:57:35 -0600 [thread overview]
Message-ID: <CAPLW+4kBHnLnPj0JKvdQ-Bm7DiEJ+_Ob-Cw60=vzwDwbOh4qOA@mail.gmail.com> (raw)
In-Reply-To: <c4f7e3cb-db9b-48be-883e-33878d2510e8@linaro.org>
On Thu, Feb 22, 2024 at 1:47 AM Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> On 22/02/2024 01:42, Sam Protsenko wrote:
> > On Tue, Feb 20, 2024 at 5:04 AM Krzysztof Kozlowski
> > <krzysztof.kozlowski@linaro.org> wrote:
> >>
> >> On 16/02/2024 23:32, Sam Protsenko wrote:
> >>> Abstract CPU clock registers by keeping their offsets in a dedicated
> >>> chip specific structure to accommodate for oncoming Exynos850 support,
> >>> which has different offsets for cluster 0 and cluster 1. This rework
> >>> also makes it possible to use exynos_set_safe_div() for all chips, so
> >>> exynos5433_set_safe_div() is removed here to reduce the code
> >>> duplication.
> >>>
> >>
> >> So that's the answer why you could not use flags anymore - you need an
> >> enum, not a bitmap. Such short explanation should be in previous commits
> >> justifying moving reg layout to new property.
> >
> > Will do, thanks.
> >
> >>
> >>> No functional change.
> >>>
> >>> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> >>> ---
> >>> drivers/clk/samsung/clk-cpu.c | 156 +++++++++++++++++++---------------
> >>> 1 file changed, 86 insertions(+), 70 deletions(-)
> >>>
> >>> diff --git a/drivers/clk/samsung/clk-cpu.c b/drivers/clk/samsung/clk-cpu.c
> >>> index 04394d2166c9..744b609c222d 100644
> >>> --- a/drivers/clk/samsung/clk-cpu.c
> >>> +++ b/drivers/clk/samsung/clk-cpu.c
> >>> @@ -44,12 +44,14 @@ typedef int (*exynos_rate_change_fn_t)(struct clk_notifier_data *ndata,
> >>>
> >>> /**
> >>> * struct exynos_cpuclk_chip - Chip specific data for CPU clock
> >>> + * @regs: register offsets for CPU related clocks
> >>> * @pre_rate_cb: callback to run before CPU clock rate change
> >>> * @post_rate_cb: callback to run after CPU clock rate change
> >>> */
> >>> struct exynos_cpuclk_chip {
> >>> - exynos_rate_change_fn_t pre_rate_cb;
> >>> - exynos_rate_change_fn_t post_rate_cb;
> >>> + const void * const regs;
> >>
> >> Why this is void?
> >>
> >
> > Different chips can have very different register layout. For example,
> > older Exynos chips usually keep multiple CPU divider ratios in one
> > single register, whereas more modern chips have a dedicated register
> > for each divider clock. Also, old chips usually split divider ratio vs
> > DIV clock status between different registers, but in modern chips they
> > both live in one single register. Having (void *) makes it possible to
> > keep pointers to different structures, and each function for the
> > particular chip can "know" which exactly structure is stored there,
> > casting (void *) to a needed type. Another way to do that would be to
> > have "one-size-fits-all" structure with all possible registers for all
> > possible chips. I don't know, I just didn't like that for a couple of
> > reasons, so decided to go with (void *).
> >
> > I'll add some explanation in the commit message in v2.
>
> Currently the one-size-fits-all seems feasible, even if few fields are
> not matching, so I would prefer to go this approach.
>
Sure, no problem. Will fix it in v3.
> Best regards,
> Krzysztof
>
next prev parent reply other threads:[~2024-02-24 19:57 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-16 22:32 [PATCH 00/16] clk: samsung: Add CPU clocks for Exynos850 Sam Protsenko
2024-02-16 22:32 ` [PATCH 01/16] dt-bindings: clock: exynos850: Add CMU_CPUCLK0 and CMU_CPUCL1 Sam Protsenko
2024-02-16 22:32 ` [PATCH 02/16] clk: samsung: Improve clk-cpu.c style Sam Protsenko
2024-02-16 22:32 ` [PATCH 03/16] clk: samsung: Pull struct exynos_cpuclk into clk-cpu.c Sam Protsenko
2024-02-16 22:32 ` [PATCH 04/16] clk: samsung: Reduce params count in exynos_register_cpu_clock() Sam Protsenko
2024-02-16 22:32 ` [PATCH 05/16] clk: samsung: Use single CPU clock notifier callback for all chips Sam Protsenko
2024-02-16 22:32 ` [PATCH 06/16] clk: samsung: Group CPU clock functions by chip Sam Protsenko
2024-02-16 22:32 ` [PATCH 07/16] clk: samsung: Pass actual clock controller base address to CPU_CLK() Sam Protsenko
2024-02-20 10:53 ` Krzysztof Kozlowski
2024-02-21 23:41 ` Sam Protsenko
2024-02-16 22:32 ` [PATCH 08/16] clk: samsung: Use clk.h as a single header for Samsung CCF Sam Protsenko
2024-02-20 10:55 ` Krzysztof Kozlowski
2024-02-16 22:32 ` [PATCH 09/16] clk: samsung: Pass register layout type explicitly to CLK_CPU() Sam Protsenko
2024-02-20 10:56 ` Krzysztof Kozlowski
2024-02-16 22:32 ` [PATCH 10/16] clk: samsung: Keep CPU clock chip specific data in a dedicated struct Sam Protsenko
2024-02-16 22:32 ` [PATCH 11/16] clk: samsung: Keep register offsets in chip specific structure Sam Protsenko
2024-02-20 11:04 ` Krzysztof Kozlowski
2024-02-22 0:42 ` Sam Protsenko
2024-02-22 7:47 ` Krzysztof Kozlowski
2024-02-24 19:57 ` Sam Protsenko [this message]
2024-02-16 22:32 ` [PATCH 12/16] clk: samsung: Pass mask to wait_until_mux_stable() Sam Protsenko
2024-02-16 22:32 ` [PATCH 13/16] clk: samsung: Add CPU clock support for Exynos850 Sam Protsenko
2024-02-16 22:32 ` [PATCH 14/16] clk: samsung: Implement manual PLL control for ARM64 SoCs Sam Protsenko
2024-02-16 22:32 ` [PATCH 15/16] clk: samsung: exynos850: Add CMU_CPUCL0 and CMU_CPUCL1 Sam Protsenko
2024-02-16 22:32 ` [PATCH 16/16] arm64: dts: exynos: Add CPU clocks Sam Protsenko
2024-02-20 11:07 ` [PATCH 00/16] clk: samsung: Add CPU clocks for Exynos850 Krzysztof Kozlowski
2024-02-21 23:07 ` Sam Protsenko
2024-02-22 7:45 ` Krzysztof Kozlowski
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAPLW+4kBHnLnPj0JKvdQ-Bm7DiEJ+_Ob-Cw60=vzwDwbOh4qOA@mail.gmail.com' \
--to=semen.protsenko@linaro.org \
--cc=alim.akhtar@samsung.com \
--cc=conor+dt@kernel.org \
--cc=cw00.choi@samsung.com \
--cc=devicetree@vger.kernel.org \
--cc=krzysztof.kozlowski@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=mturquette@baylibre.com \
--cc=robh@kernel.org \
--cc=s.nawrocki@samsung.com \
--cc=sboyd@kernel.org \
--cc=tomasz.figa@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).