[PATCH v3 0/3] Make Armada 375 use the reference clock when possible

Daniel Lezcano daniel.lezcano at linaro.org
Wed Nov 19 01:25:58 PST 2014

On 11/04/2014 02:21 PM, Ezequiel Garcia wrote:
> Hi Daniel, Wim:
> Seems we are ready to merge these, unless some objection raises. Do you think
> you can take the patches through your trees?

Hi Wim,

I can take through my tree the entire patchset if you want but I need 
your blessing for the watchdog part.

   -- Daniel

> Changes from v2:
>    * Fix messed up empty lines, as suggested by Thomas Petazzoni.
> Changes from v1:
>    * Make the A375 timer and watchdog devicetree binding match the hardware
>      and require the two available clocks: core and reference clock.
> This series adds support for the 25 MHz reference clock available on
> Armada 375 SoC to be used on the timer and watchdog drivers. It is
> similar to the one present in Armada XP SoC.
> Given we initially had access to only a very early SoC revision (A375 Z1)
> and due to a hardware issue, the timer and watchdog support was originally
> submitted to use the core clock.
> Now that the A0 SoC revision is out, we can fix this and use the reference
> clock. The reason for this change is that the core clock is subject to the
> SSCG (Spread Spectrum Clock Generator), so boards where SSCG is enabled
> exhibit a very large timer drift.
> Notice that this change will produce unpleseant results on A375 Z1, given the
> reference 25 MHz clock doesn't work properly on that SoC revision.
> But since the Z1 revision is not supported by the recently submitted A375
> network driver (mvpp2), and therefore nobody is expected to run mainline
> (if there are users at all of this early revision), the support will be
> dropped entirely in a near future.
> To prevent any compatibility issues when booting with an older devicetree,
> this series provides proper fall backs in each case.
> The series applies on v3.18-rc2.
> Ezequiel Garcia (3):
>    clocksource: armada-370-xp: Add missing clock enable
>    watchdog: orion: Use the reference clock on Armada 375 SoC
>    clocksource: armada-370-xp: Use the reference clock on A375 SoC
>   .../bindings/timer/marvell,armada-370-xp-timer.txt |  9 +++--
>   .../devicetree/bindings/watchdog/marvel.txt        | 13 +++++++
>   drivers/clocksource/time-armada-370-xp.c           | 30 ++++++++++++++++
>   drivers/watchdog/orion_wdt.c                       | 42 +++++++++++++++++++++-
>   4 files changed, 90 insertions(+), 4 deletions(-)

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