On Tue, 11 Aug 2015, Michael Turquette wrote:

Quoting Geert Uytterhoeven (2015-08-11 03:11:05)

quoted

Hi Maxime,

On Tue, Aug 11, 2015 at 12:02 PM, Maxime Coquelin
[off-list ref] wrote:

quoted

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;

quoted

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)

Thanks.

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".

Easy, how about:

'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'

Or

I could come up with something else?

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
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