From: heiko@sntech.de (Heiko Stübner)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 6/7] ARM: dts: rockchip: add core rk3288 dtsi
Date: Fri, 25 Jul 2014 21:45:11 +0200 [thread overview]
Message-ID: <1698904.IucsPH3YuJ@diego> (raw)
In-Reply-To: <20140725193906.22930.61548@quantum>
Am Freitag, 25. Juli 2014, 12:39:06 schrieb Mike Turquette:
> Quoting Doug Anderson (2014-07-24 16:06:34)
>
> > > + xin24m: xin24m {
> > > + compatible = "fixed-clock";
> > > + clock-frequency = <24000000>;
> > > + #clock-cells = <0>;
> > > + };
> >
> > I'm no expert, but strangely every other .dts seems to have the clocks
> > under a "clocks" node. That seems to contradict the suggestion made
> > previously that things should not be on the top level, though.
>
> That usually happens when there is a clock controller (e.g. "clocks")
> that has multiple clock signals coming out of it. Typically this is for
> a clock generator IP within a SoC or other chip.
>
> However for a single board-level clock such as an osc then it is common
> to put it at a top-level for that board since these can change from
> board to board.
All Rockchip manuals I have (from rk3066 forward) state that the oscillator
used here must be 24MHz, so I guess it should be ok in the main dtsi files.
In the very unlikely case that a hw designer ignored every piece of
documentation I guess they could simply reset the clock-frequency value in
their board dts.
>
> > Also, _I think_ device tree suggests a more generic name for the node
> > like "oscillator". You could use "xin24m" as an output name, I think.
> > Mike could correct me if I'm wrong.
>
> You are correct.
I'll rename it.
Heiko
WARNING: multiple messages have this Message-ID (diff)
From: "Heiko Stübner" <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
To: Mike Turquette <mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Doug Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
"linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
Olof Johansson <olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org>,
"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Eddie Cai <eddie.cai-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Subject: Re: [PATCH v2 6/7] ARM: dts: rockchip: add core rk3288 dtsi
Date: Fri, 25 Jul 2014 21:45:11 +0200 [thread overview]
Message-ID: <1698904.IucsPH3YuJ@diego> (raw)
In-Reply-To: <20140725193906.22930.61548@quantum>
Am Freitag, 25. Juli 2014, 12:39:06 schrieb Mike Turquette:
> Quoting Doug Anderson (2014-07-24 16:06:34)
>
> > > + xin24m: xin24m {
> > > + compatible = "fixed-clock";
> > > + clock-frequency = <24000000>;
> > > + #clock-cells = <0>;
> > > + };
> >
> > I'm no expert, but strangely every other .dts seems to have the clocks
> > under a "clocks" node. That seems to contradict the suggestion made
> > previously that things should not be on the top level, though.
>
> That usually happens when there is a clock controller (e.g. "clocks")
> that has multiple clock signals coming out of it. Typically this is for
> a clock generator IP within a SoC or other chip.
>
> However for a single board-level clock such as an osc then it is common
> to put it at a top-level for that board since these can change from
> board to board.
All Rockchip manuals I have (from rk3066 forward) state that the oscillator
used here must be 24MHz, so I guess it should be ok in the main dtsi files.
In the very unlikely case that a hw designer ignored every piece of
documentation I guess they could simply reset the clock-frequency value in
their board dts.
>
> > Also, _I think_ device tree suggests a more generic name for the node
> > like "oscillator". You could use "xin24m" as an output name, I think.
> > Mike could correct me if I'm wrong.
>
> You are correct.
I'll rename it.
Heiko
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next prev parent reply other threads:[~2014-07-25 19:45 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-18 0:18 [PATCH v2 0/7] ARM: rockchip: add initial support for rk3288 Heiko Stübner
2014-07-18 0:18 ` Heiko Stübner
2014-07-18 0:19 ` [PATCH v2 1/7] dt-bindings: arm: add cortex-a12 and cortex-a17 cpu compatible properties Heiko Stübner
2014-07-18 0:19 ` Heiko Stübner
2014-07-18 0:19 ` [PATCH v2 2/7] ARM: rockchip: clarify usability of DEBUG_RK3X_UART debug_ll options Heiko Stübner
2014-07-18 0:19 ` Heiko Stübner
2014-07-25 3:49 ` Doug Anderson
2014-07-25 3:49 ` Doug Anderson
2014-07-18 0:20 ` [PATCH v2 3/7] ARM: rockchip: add debug uart used by rk3288 Heiko Stübner
2014-07-18 0:20 ` Heiko Stübner
2014-07-18 0:20 ` [PATCH v2 4/7] ARM: Kconfig: set default gpio number for rockchip SoCs Heiko Stübner
2014-07-18 0:20 ` Heiko Stübner
2014-07-18 0:21 ` [PATCH v2 5/7] ARM: rockchip: enable support for RK3288 SoCs Heiko Stübner
2014-07-18 0:21 ` Heiko Stübner
2014-07-25 3:50 ` Doug Anderson
2014-07-25 3:50 ` Doug Anderson
2014-07-18 0:21 ` [PATCH v2 6/7] ARM: dts: rockchip: add core rk3288 dtsi Heiko Stübner
2014-07-18 0:21 ` Heiko Stübner
2014-07-18 9:35 ` Mark Rutland
2014-07-18 9:35 ` Mark Rutland
2014-07-18 9:49 ` Heiko Stübner
2014-07-18 9:49 ` Heiko Stübner
2014-07-24 23:06 ` Doug Anderson
2014-07-24 23:06 ` Doug Anderson
2014-07-25 19:39 ` Mike Turquette
2014-07-25 19:39 ` Mike Turquette
2014-07-25 19:45 ` Heiko Stübner [this message]
2014-07-25 19:45 ` Heiko Stübner
2014-07-18 0:21 ` [PATCH v2 7/7] ARM: dts: add rk3288 evaluation board Heiko Stübner
2014-07-18 0:21 ` Heiko Stübner
2014-07-24 23:17 ` Doug Anderson
2014-07-24 23:17 ` Doug Anderson
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