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    SubjectRe: [PATCH RFC RFT 3/3] clk: introduce CLK_ENABLE_HAND_OFF flag
    Date
    Quoting Geert Uytterhoeven (2015-08-11 03:11:05)
    > Hi Maxime,
    >
    > On Tue, Aug 11, 2015 at 12:02 PM, Maxime Coquelin
    > <maxime.coquelin@st.com> wrote:
    > > How can we pass CLK_ENABLE_HAND_OFF flag to a specific clock on STi
    > > platform?
    >
    > Add the flag to the relevant clocks in the C code, e.g. in
    > clk_register_flexgen():
    >
    > if (!strcmp(name, "clk-icn-cpu"))
    > init.flags |= CLK_ENABLE_HAND_OFF;
    >
    > > Could we imagine having a kind of "clocks-enable-hand-off" property we could
    > > use in our clock controller DT node?
    >
    > You can imagine doing "flex_flags |= CLK_ENABLE_HAND_OFF" in
    > st_of_flexgen_setup(), depending on the presence of such a property.

    This is precisely what Lee is trying to avoid. The would constitute a
    hand-rolled, open-code, gather-and-mark exercise that drivers would have
    to re-invent each time. (rough paraphrase of what Lee said)

    I think that we can come up with a reasonable DT wrapper around the
    flag. I will be ecstatic if we can agree that the meaning of the flag
    can be tweaked just a bit to mean, "prevent this critical clock from
    being disabled, as it was enabled out of reset or by the bootloader,
    until a driver claims it and calls clk_prepare_enable".

    Then everyone should be happy.

    Regards,
    Mike

    >
    > However, not disabling clocks is a software policy, not a hardware description,
    > so IMHO it doesn't belong in DT.
    >
    > Gr{oetje,eeting}s,
    >
    > Geert
    >
    > --
    > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
    >
    > In personal conversations with technical people, I call myself a hacker. But
    > when I'm talking to journalists I just say "programmer" or something like that.
    > -- Linus Torvalds
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