[PATCH 2/5] clk: lpc32xx: read-only divider can propagate rate change

Jerome Brunet jbrunet at baylibre.com
Mon Jan 8 01:10:39 PST 2018


On Sat, 2018-01-06 at 16:04 +0200, Vladimir Zapolskiy wrote:
> > I added the fix to LPC32xx because it looks like the generic divider (a lot) and
> 
> right, the relevant divider operations were copied, however the difference
> is important, unfortunately there is no simple option to get rid of regmap,
> because System Control Block registers are shared with a number of other
> device drivers.

I have the same issue ;)

> 
> > appears to support CLK_DIVIDER_READ_ONLY. If it does not, could you please kill
> > the related code ?
> 
> The driver supports CLK_DIVIDER_READ_ONLY clocks, and it should not be
> changed, but all such clocks don't have children with CLK_SET_RATE_PARENT
> property, which invalidates your fix for LPC32xx. Please let me know,
> if I missed something.

You did not miss anything. I understand your choice.
I just have different approach and usually prefer to avoid these particularity
which may catch you later on. 

At least, the fact that propagation would stop with CLK_DIVIDER_READ_ONLY on
LPC32xx, even with CLK_SET_RATE_PARENT, is now known.

Adding a comment in the code to make this explicit would be nice though.

Regards
Jerome



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