Messages in this thread | | | From | Michael Turquette <> | Subject | Re: [PATCH RFC RFT 3/3] clk: introduce CLK_ENABLE_HAND_OFF flag | Date | Tue, 11 Aug 2015 10:09:28 -0700 |
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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 > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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