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    SubjectRe: [PATCH v5 12/44] clk: davinci: Add platform information for TI DA850 PSC
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    On Monday 23 April 2018 08:29 PM, David Lechner wrote:
    > On 04/06/2018 11:46 AM, Stephen Boyd wrote:
    >> Quoting Sekhar Nori (2018-04-06 02:37:03)
    >>>
    >>> Can you please check that and confirm there is no issue with genpd and
    >>> using CLK_OF_DECLARE() to initialize clocks?
    >>>
    >>> Unless you report an issue back, or Mike and Stephen have ideas about
    >>> how to handle the dependency between PSC/PLL derived timer clock
    >>> initialization and and timer_probe(), I think we need to move back to
    >>> using CLK_OF_DECLARE().
    >>
    >> In such a case, please use the hybrid approach where the clks required
    >> for the clockevent and/or clocksource are registered in the early
    >> CLK_OF_DECLARE path but the rest of the clks get registered with a
    >> proper platform device and driver. There are examples of this approach
    >> on other platforms already.
    >>
    >
    > I looked at this a bit last week, but I didn't come up with any approach
    > that I was happy with. It seems like it would be nice to just register
    > the absolute minimum clocks needed. On DA8XX, that would just be the PLL0
    > AUXCLK. On most of the other SoCs, it would be the PLL AUXCLK plus one
    > LPSC clock. The AUXCLKs are easy because they are just a simple gate
    > from the oscillator. The LPSC clocks are a bit more tricky because they
    > have a complex sequence for turning on. Furthermore, on DM646X, we need
    > the whole PLL up to SYSCLK3 plus one LPSC clock, so things get a bit
    > messy there.

    Things might change in the context of work being done here by Bartosz
    for converting clocks to early platform devices.

    But, keeping that development aside for a moment: I think this means the
    PLLs and PSCs need to be CLK_OF_DECLARE(). What we can have as platform
    devices are clocks that are not in the path to get timer clock working
    (like CFGCHIP clocks).

    Thanks,
    Sekhar

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