lkml.org 
[lkml]   [2018]   [Nov]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH] arm64: dts: rockchip: rk3399: Add xin32k clk
Date
Am Freitag, 16. November 2018, 19:23:59 CET schrieb Doug Anderson:
> Hi,
>
> On Fri, Nov 16, 2018 at 9:39 AM dbasehore . <dbasehore@chromium.org> wrote:
> > On Fri, Nov 16, 2018 at 8:01 AM Doug Anderson <dianders@chromium.org>
wrote:
> > > Hi,
> > >
> > > On Thu, Nov 15, 2018 at 9:17 PM Derek Basehore <dbasehore@chromium.org>
wrote:
> > > > This adds the xin32k clock to the RK3399 CPU. Even though it's not
> > > > directly used, muxes will end up traversing the entire clk tree on
> > > > calls to determine_rate if it doesn't exist.
> > > >
> > > > Signed-off-by: Derek Basehore <dbasehore@chromium.org>
> > > > ---
> > > >
> > > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 7 +++++++
> > > > 1 file changed, 7 insertions(+)
> > >
> > > nit: I would have expected ${SUBJECT} to have v2 in it somewhere.
> > >
> > > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> > > > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index
> > > > 99e7f65c1779..3d09472978f8 100644
> > > > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> > > > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> > >
> > > Aww crud. I was at the airport yesterday and so I didn't notice that
> > > you were touching rk3399, not rk3399-gru. This belongs in the gru
> > > device tree file, not in the top level rk3399. As you have written
> >
> > > this it will break rk3399 boards that have an rk808 on them, AKA:
> > Should this be moved to the rk3399.dtsi file? The RK3399 assumes that
> > this clk exists (same as the 24MHz clk which is in rk3399.dtsi). While
> > it can function without it defined, it really shouldn't. We can just
> > assign the existing labels in the dts files you pointed out.
>
> No, it should be in the board files. Each board may produce the 32k
> clock through a different component. On gru-based devices we produce
> the 32k clock through a silego part.

That would also be a great part of the commit message, like
"...on Gru boards the 32kHz clock gets produced by a Silego oscillator"
or so when you move it over to rk3399-gru.dtsi .


> Technically you could say that we don't _truly_ need to model this
> clock and we could have just inserted a dummy/fixed 32k clock in the
> clk-rk3399.c file. ...but we did model it so that means we should
> probably model it semi-properly.
>
> If a given board forgets to provide a 32k clock then that's a bug for
> them like it was for us.

Yep and as I said in my other mail, on these pmic generated clocks
the clock generation often even is configurable (rate, on/off), so it
should really be a real clock not some hack ;-) .


Heiko


\
 
 \ /
  Last update: 2018-11-19 10:42    [W:0.059 / U:4.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site