[PATCH 1/3] clk: meson: meson8b: add compatibles for Meson8 and Meson8m2
Jerome Brunet
jbrunet at baylibre.com
Mon Jun 12 00:40:25 PDT 2017
On Fri, 2017-06-09 at 11:13 -0700, Kevin Hilman wrote:
> Jerome Brunet <jbrunet at baylibre.com> writes:
>
> > On Sun, 2017-06-04 at 20:33 +0200, Martin Blumenstingl wrote:
> > > The clock controller on Meson8, Meson8b and Meson8m2 is very similar
> > > based on the code from the Amlogic GPL kernel sources. Add separate
> > > compatibles for each SoC to make sure that we can easily implement
> > > all the small differences for each SoC later on.
> > >
> > > In general the Meson8 and Meson8m2 seem to be almost identical as they
> > > even share the same mach-meson8 directory in Amlogic's GPL kernel
> > > sources.
> > > The main clocks on Meson8, Meson8b and Meson8m2 are very similar,
> > > because they are all using the same PLL values, 90% of the clock gates
> > > are the same (the actual diffstat of the mach-meson8/clock.c and
> > > mach-meson8b/clock.c files is around 30 to 40 lines, when excluding
> > > all commented out code).
> > > The difference between the Meson8 and Meson8b clock gates seem to be:
> > > - Meson8 has AIU_PCLK, HDMI_RX, VCLK2_ENCT, VCLK2_ENCL, UART3,
> > > CSI_DIG_CLKIN gates which don't seem to be available on Meson8b
> > > - the gate on Meson8 for bit 7 seems to be named "_1200XXX" instead
> > > of "PERIPHS_TOP" (on Meson8b)
> > > - Meson8b has a SANA gate which doesn't seem to exist on Meson8 (or
> > > on Meson8 the same bit is used by the UART3 gate in Amlogic's GPL
> > > kernel sources)
> > > None of these gates is added for now, since it's unclear whether these
> > > definitions are actually correct (the VCLK2_ENCT gate for example is
> > > defined, but only used in some commented block).
> > >
> > > The main difference between all three SoCs seem to be the video (VPU)
> > > clocks. Apart from different supported clock rates (according to vpu.c
> > > in mach-meson8 and mach-meson8b from Amlogic's GPL kernel sources) the
> > > most notable difference is that Meson8m2 has a GP_PLL clock and a mux
> > > (probably the same as on the Meson GX SoCs) to support glitch-free
> > > (clock rate) switching.
> > > None of these VPU clocks are not supported by our mainline meson8b
> > > clock driver yet though.
> > >
> > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
> > > ---
> > > .../devicetree/bindings/clock/amlogic,meson8b-clkc.txt | 11
> > > +++++++---
> >
> > I think you should split the binding documentation and clk changes into
> > separate
> > patches.
> >
> > > -
> > > drivers/clk/meson/Kconfig | 6 +++---
> > > drivers/clk/meson/meson8b.c | 5 ++++-
> >
> > The change being more platform than clock related, I'd prefer if Kevin or
> > Carlo
> > ack it before we apply it.
>
> Acked-by: Kevin Hilman <khilman at baylibre.com>
Applied to next/drivers with Kevin and Rob's Acks.
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