On 2016년 07월 02일 09:20, Stephen Boyd wrote:

On 06/29, Jongsung Kim wrote:

quoted

On 2016년 06월 29일 06:18, Michael Turquette wrote:

quoted

Quoting Rob Herring (2016-06-28 13:55:18)

quoted

On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote:

quoted

There is no way to set additional flags for a DT-initialized fixed-
factor-clock, and it can be problematic i.e., when the clock rate
needs to be changed. [1][2]

This patch introduces an optional dt-binding named "clock-flags" to
be used for passing any needed flags from dts.

I don't think we want this in DT. If we did, the flags would need some 
documentation about what the flags mean.

Flags are specific to Linux implementation, so I agree with Rob. Better
to create a compatible string for your hardware that bakes in the flags.

Thank you for your comment, Mike. This conversation starts from lacking method to set CLK_SET_RATE_PARENT from DT. I understand compatible string can be a solution. But.. if someone starts talking about lacking method to set another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another compatible string list.
How do you think about defining possible required subset of the flags and using some more neutral flag-names acceptable in DT?

Do you actually have an IC on the board that is doing some fixed
factor calculation? Or is this a clk driver design where we are
listing out each piece of an SoC's clk controller in DT?

The SoC has several PLLs of identical design, and one of them is divided
to half and used for CPUs. The fixed-factor-clock represents the divider.