[PATCH v3 0/4] DT clock bindings

On 06/15/2012 02:39 AM, Shawn Guo wrote:

On Tue, Jun 12, 2012 at 09:41:47AM -0500, Rob Herring wrote:

quoted

I'm posting this again to solicit further review. There has been some
discussion[1], but no definite path forward. This series is not changed
from the last post other than rebasing to v3.5-rc2.

Hi Rob,

Per your comment[1], the patch below takes imx6q as example to define
single CCM node with a whole bunch of outputs to support clk lookup
with device tree.  (Only uart and usdhc clocks are being put there for
demonstration.)  Though it seems working, going through the patch you
will see a couple problems which may need to be solved to make the
binding useful for cases like imx.

...

* phandle argument is not easy for engineering

As we will have a whole bunch of clock outputs listed in ccm node,
which will be referenced by peripheral phandle in form of <&clks index>.
When the list gets long, it becomes hard for people to find the correct
index number for the clock referenced.

You can (well, probably /should/) list the clock IDs as well as names in
the binding documentation. Then, there's no guess-work or counting
involved. I did this in a very early Tegra clock binding proposal:

http://patchwork.ozlabs.org/patch/141359/

Hopefully, dtc will grow named-constants or a pre-processor sometime and
help this too.