[PATCH] clk: debug clock tree

On Sun, Dec 23, 2012 at 4:26 AM, Prashant Gaikwad [off-list ref] wrote:

On Saturday 22 December 2012 04:26 AM, Mike Turquette wrote:

quoted

On Wed, Dec 19, 2012 at 11:53 PM, Prashant Gaikwad [off-list ref]
wrote:

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On Thursday 13 December 2012 11:31 PM, Stephen Warren wrote:

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On 12/13/2012 09:27 AM, Mike Turquette wrote:

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On Wed, Dec 12, 2012 at 7:49 PM, Prashant Gaikwad [off-list ref]
wrote:

quoted

Adds debug file "clock_tree" in /sys/kernel/debug/clk dir.
It helps to view all the clock registered in tree format.

Prashant,

Thanks for submitting this.  We've been talking about having a single
file for representing the tree for some time.

Regarding the output format had you considered using a well known
format which can be parsed using well known parsing libs?  This avoids
needing a custom parser just for this one file.  JSON springs to mind
as something lightweight and well-understood.

One advantage of the format below is that it's very easily
human-readable, and it's not too hard to parse (although I guess you'd
have to parse the indent level to get parent/child relation, which would
suck a bit). Is there room to provide both? Otherwise, I guess the
kernel could include a script to convert from JSON/whatever into the
format below.

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For example:
     clock                        enable_cnt  prepare_cnt  rate
---------------------------------------------------------------------
   i2s0_sync                      0           0            24000000
   spdif_in_sync                  0           0            24000000
      spdif_mux                   0           0            24000000
         spdif                    0           0            24000000
            spdif_doubler         0           0            48000000
               spdif_div          0           0            48000000
                  spdif_2x        0           0            48000000

Even I think that output must be easily human-readable. How about adding
sysfs to switch between human-readable and machine-readable format?
I will try come up with a implementation.

Do you mean a sysfs file which controls the output format?  How about
just two different files?  One can be clk-dump (machine readable) and
the other is clk-summary (human readable).

It is also fine. Is this patch ok for human-readable format? or any
suggestions?
I will change the file name to clk-summary.

Prashant,

Yes the format seems to be agreeable for human-readable format based
on the feedback on the list.  Go ahead and keep the column titles and
the dashed lines that I commented on earlier... my comments are less
relevant if a separate machine-readable clk-dump file exists.

Are you going to take a crack at JSON-formatted output for clk-dump?

Thanks,
Mike

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Regards,
Mike