linux-kernel - Re: [PATCH v2 0/4] Meson8b: add the CPU clock post-dividers

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Message-ID: <CAFBinCBExC-ZpD4RfzESv41fUZCODrv-VFODTKLrwAUC1UO+5w@mail.gmail.com>
Date:   Fri, 23 Nov 2018 20:40:06 +0100
From:   Martin Blumenstingl <martin.blumenstingl@...glemail.com>
To:     Neil Armstrong <narmstrong@...libre.com>
Cc:     linux-amlogic@...ts.infradead.org, jbrunet@...libre.com,
        mturquette@...libre.com, sboyd@...nel.org,
        linux-clk@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 0/4] Meson8b: add the CPU clock post-dividers

On Fri, Nov 23, 2018 at 3:40 PM Neil Armstrong <narmstrong@...libre.com> wrote:
>
> On 22/11/2018 22:40, Martin Blumenstingl wrote:
> > This is the successor to my previous series "meson8b: add the CPU_DIV16
> > clock for the ARM TWD" from [0]. I decided to not send this as v2 of
> > the original series because the PERIPH clock is not the CPU_DIV16 clock.
> > It's not clear whether a CPU_DIV16 clock exists.
> >
> > With this series we get all the CPU_CLK post-dividers as listed in the
> > public S805 datasheet [1] on pages 31 and 32:
> > - ABP
> > - PERIPH (used as input for the ARM global timer and ARM TWD timer)
> > - AXI
> > - L2 DRAM
> >
> > Each of these clocks has a register called "..._CLK_DIS" which is
> > documented as a "just in case" bit:
> > "Set to 1 to manually disable the [...] clock when changing the mux
> > selection. Typically this bit is set to 0 since the clock muxes can
> > switch without glitches."
> > Since we're not supposed to touch that register we're using the new
> > read-only gate clk_ops to ensure that nothing accidentally modifies
> > these bits.
> >
> > The result of this is that we can use the PERIPH clock which clocks
> > the ARM TWD timer. I will send a separate series to add the TWD timer.
> >
> >
> > changes since v1 at [2]:
> > - added new patch 2 "clk: meson: clk-regmap: add read-only gate ops"
> > - switched from CLK_IS_CRITICAL to the new clk_regmap_gate_ro_ops
> >   so we're consistent with all other read-only clocks
> > - collected Jerome's Acked-by tags (thanks!)
> >
> >
> > [0] http://lists.infradead.org/pipermail/linux-amlogic/2018-July/007890.html
> > [1] https://dn.odroid.com/S805/Datasheet/S805_Datasheet%20V0.8%2020150126.pdf
> > [2] https://patchwork.kernel.org/cover/10687023/
> >
> >
> > Martin Blumenstingl (4):
> >   dt-bindings: clock: meson8b: export the CPU post dividers
> >   clk: meson: clk-regmap: add read-only gate ops
> >   clk: meson: meson8b: rename cpu_div2/cpu_div3 to
> >     cpu_in_div2/cpu_in_div3
> >   clk: meson: meson8b: add the CPU clock post divider clocks
> >
> >  drivers/clk/meson/clk-regmap.c           |   5 +
> >  drivers/clk/meson/clk-regmap.h           |   1 +
> >  drivers/clk/meson/meson8b.c              | 264 ++++++++++++++++++++++-
> >  drivers/clk/meson/meson8b.h              |  17 +-
> >  include/dt-bindings/clock/meson8b-clkc.h |   4 +
> >  5 files changed, 278 insertions(+), 13 deletions(-)
>
>
> Applied, with the bindings on next/headers
awesome, thank you Neil!
you even gave Kevin a tag with only the headers included - good for me
since I can sent the corresponding .dts patches now.


Regards
Martin