Received-SPF: pass (google.com: domain of linux-kernel+bounces-14981-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <fa32e6fae168e10d42051b89197855e9.sboyd@kernel.org>
Content-Type: text/plain; charset="utf-8"
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
In-Reply-To: <CXUTPV1ZOSID.323RSEP4BL2AT@bootlin.com>
References: <20231218-mbly-clk-v1-0-44ce54108f06@bootlin.com> <20231218-mbly-clk-v1-3-44ce54108f06@bootlin.com> <a8f740c7a8c1222d4a42bad588c75e87.sboyd@kernel.org> <CXUTPV1ZOSID.323RSEP4BL2AT@bootlin.com>
Subject: Re: [PATCH 3/5] clk: eyeq5: add controller
From: Stephen Boyd <sboyd@kernel.org>
Cc: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com>, linux-mips@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Petazzoni <thomas.petazzoni@bootlin.com>, Tawfik Bayouk <tawfik.bayouk@mobileye.com>
To: Conor Dooley <conor+dt@kernel.org>, Gregory CLEMENT <gregory.clement@bootlin.com>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Michael Turquette <mturquette@baylibre.com>, Rob Herring <robh+dt@kernel.org>, Thomas Bogendoerfer <tsbogend@alpha.franken.de>, =?utf-8?q?Th=C3=A9o?= Lebrun <theo.lebrun@bootlin.com>
Date: Tue, 02 Jan 2024 15:42:45 -0800
User-Agent: alot/0.10

Quoting Th=C3=A9o Lebrun (2023-12-22 03:25:12)
> On Wed Dec 20, 2023 at 12:09 AM CET, Stephen Boyd wrote:
> > Quoting Th=C3=A9o Lebrun (2023-12-18 09:14:18)
>=20
> > > +       of_clk_add_hw_provider(np, of_clk_hw_onecell_get, data);
> > > +}
> > > +
> > > +CLK_OF_DECLARE_DRIVER(eq5c, "mobileye,eyeq5-clk", eq5c_init);
> >
> > Please use a platform driver.
>=20
> I've been trying to do that but I had a stall at boot. I initially
> associated it with the UART driver acquiring a clock too early but
> instead it is the CPU timer clocksource driver that consumes one of our
> clock way earlier than any platform driver initialisation.
>=20
> The clocksource driver we are talking about is this one for reference:
> https://elixir.bootlin.com/linux/v6.6.8/source/drivers/clocksource/mips-g=
ic-timer.c
>=20
> Its usage of TIMER_OF_DECLARE means it gets probed by timer_probe ->
> plat_time_init -> time_init -> start_kernel. This is way before any
> initcalls. Our prior use of CLK_OF_DECLARE_DRIVER meant that we got
> probed by of_clk_init -> plat_time_init.
>=20
> I'm guessing we are not the first one in this situation; any advice on
> how to deal with it?
>=20

You guessed correctly. In that case, use CLK_OF_DECLARE_DRIVER() and
register the clk(s) needed for the timer in that function. Other clks
shall be registered with a platform driver.