[PATCH RFC] clk: divider: Tolerate 0 divider for one based dividers

[mturquette@linaro.org (Mike Turquette)]

Quoting S?ren Brinkmann (2013-04-01 11:31:32)
> Hi Mike,
> 
> On Mon, Apr 01, 2013 at 11:25:22AM -0700, Mike Turquette wrote:
> > Quoting S?ren Brinkmann (2013-03-22 11:00:15)
> > > Since some of our dividers have a reset value of 0, I see this warning
> > > during boot up. My intention here is to get rid of the warning for clocks
> > > which deem 0 a valid divider value.
> > > I thought, reusing the ONE_BASED flag might be okay, since all such
> > > dividers have this redundant 0 state and might handle it similar.
> > > Otherwise a new flag might be required.
> > > 
> > 
> > Hi Soren,
> > 
> > A flag will be necessary.  I just checked some documentation for the
> > divider outputs for OMAP's PLLs and (which use the common clk_divider
> > type) and programming zero into those dividers is not allowed.  At reset
> > the divider registers are set to 1.
> > 
> > So it is unsafe to simply reuse the ONE_BASED flag.
> > 
> > Let's keep the current behavior as the default and introduce a new flag
> > to handle the special case of a zero divider.  Would you like to take a
> > crack at it?  It might also be nice to update the WARN message with a
> > hint to take a look at your new flag in case future platforms hit the
> > same issue as you.
> Okay, sounds good. I should be able to get something ready within this
> week.
> Does anybody have suggestions for naming the new flag?
> CLK_DIVIDER_ZERO_OKAY was my original suggestionn I think.
> 

CLK_DIVIDER_ALLOW_ZERO sounds betterer to me.

Regards,
Mike

>         S?ren