Re: [PATCH v4 0/5] Binding and driver for gated-fixed-clocks

From: "Heiko Stübner" <heiko@sntech.de>
To: Dragan Simic <dsimic@manjaro.org>
Cc: mturquette@baylibre.com, sboyd@kernel.org, robh@kernel.org,
	krzk+dt@kernel.org, conor+dt@kernel.org,
	linux-clk@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org
Subject: Re: [PATCH v4 0/5] Binding and driver for gated-fixed-clocks
Date: Sun, 13 Oct 2024 22:27:39 +0200	[thread overview]
Message-ID: <2342287.ElGaqSPkdT@diego> (raw)
In-Reply-To: <3dd94272e827703c2a2a390fcbd9ff5b@manjaro.org>

Am Sonntag, 13. Oktober 2024, 21:58:41 CEST schrieb Dragan Simic:
> Hello Heiko,
> 
> On 2024-09-06 10:25, Heiko Stuebner wrote:
> > Rockchip boards with PCIe3 controllers inside the soc (rk3568, rk3588) 
> > have
> > external oscillators on the board to generate the needed 100MHz 
> > reference
> > clock the PCIe3 controller needs.
> > 
> > Often these clock generators need supplies to be enabled to run.
> > 
> > Modelling this clock has taken a number of shapes:
> > - The rk3568 Rock-3a modelled the generator-regulator as "phy-supply" 
> > [0]
> >   &pcie30phy {
> >   	phy-supply = <&vcc3v3_pi6c_03>;
> >   	status = "okay";
> >   };
> >   which is of course not part of the binding
> > 
> > - On the Rock-5-ITX the supply of the clock generator is controlled by
> >   the same gpio as the regulator supplying the the port connected to 
> > the
> >   pcie30x4 controller, so if this controller probes first, both
> >   controllers will just run. But if the pcie30x2 controller probes 
> > first
> >   (which has a different supply), the controller will stall at the 
> > first
> >   dbi read.
> > 
> > There are other types too, where an 25MHz oscillator supplies a PLL
> > chip like the diodes,pi6c557 used on Theobroma Jaguar and Tiger boards.
> > 
> > As we established in v1 [1], these are essentially different types, so
> > this series attempts to solve the first case of "voltage controlled
> > oscillators" as Stephen called them.
> > 
> > With the discussion in v2, gated-fixed-clock was deemed one possible
> > nice naming, so I did go with that.
> 
> Thanks, I find "gated-fixed-clock" a much better choice.
> 
> > Stephen also suggested reusing more of clk-gpio to not re-implement the
> > gpio handling wrt. sleeping and non-sleeping gpios.
> > 
> > Though instead of exporting masses of structs and ops, 
> > gated-fixed-clock
> > is quite close to the other gpio-clocks, so I've put it into the 
> > clk-gpio
> > file.
> 
> Just checking, what's the current state of this patch series?
> Would another review help with getting it accepted?

I guess me needing to ping Stephen to look at it now that the
merge window is done ;-) .

In the previous version he sounded ok with the naming, so hopefully
it'll just need a tiny ping.

Heiko