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[v3,0/3] OF phandle nexus support + GPIO nexus

Message ID 20170123204851.12808-1-stephen.boyd@linaro.org
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Series OF phandle nexus support + GPIO nexus | expand

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Stephen Boyd Jan. 23, 2017, 8:48 p.m. UTC 
This is one small chunk of work related to DT overlays for expansion
boards. It would be good to have a way to expose #<list>-cells types of
providers through a connector in a standard way. So we introduce a way
to make "nexus" nodes for these types of properties to remap the consumer
number space to the other side of the connector's number space. It's
basically a copy of the interrupt nexus implementation, but without
the address space matching design and interrupt-parent walking.

The first patch implements a generic method to do this, and the second patch
adds a unit test for it. The third patch is more of an example than anything
else. It shows how we would modify frameworks to use the new API.

Changes since v2:
 * Picked up Linus' ack on the gpio core patch
 * Made const stack arrays static (Rob Herring)
 * Used of_property_read_u32() instead of open coding (Rob Herring)

Changes since v1:
 * Addition of optional pass-thru parameter
 * Reduction of strings passed to 1 instead of 3 (or 4 now)
 * Updated gpio patch for the new function signature
 * Updated test-case for new funciton signature and pass-thru parameter
 * Updated kernel-doc to be correct and highlighted difference between
   this API and of_parse_phandle_with_args()

Stephen Boyd (3):
  of: Support parsing phandle argument lists through a nexus node
  of: unittest: Add phandle remapping test
  gpio: Support gpio nexus dt bindings

 drivers/gpio/gpiolib-of.c                   |   4 +-
 drivers/of/base.c                           | 184 ++++++++++++++++++++++++++++
 drivers/of/unittest-data/testcases.dts      |  11 ++
 drivers/of/unittest-data/tests-phandle.dtsi |  25 ++++
 drivers/of/unittest.c                       | 120 ++++++++++++++++++
 include/linux/of.h                          |  12 ++
 6 files changed, 354 insertions(+), 2 deletions(-)

-- 
2.10.0.297.gf6727b0

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Comments

Russell King (Oracle) Feb. 9, 2017, 3:35 p.m. UTC | #1 
On Thu, Feb 09, 2017 at 09:17:58AM -0600, Rob Herring wrote:
> Frank, any more comments on this? If not, I plan to apply this series.


Well, I find that a little annoying, because DT has the requirement
that new bindings are properly documented in Documentation, and it
appears that this comes with no documentation what so ever, despite
introducing new properties (like the -map-mask-passthru thing).

So I'm NAKing it until there's some documentation of how this
mechanism is supposed to work.

Merely providing an example in a commit log is (IMHO) insufficient.
An example doesn't explain how it was created, or how to create an
implementation.

Remember, we expect people to do exactly that, so we need to give
them this information so that they can make use of it.

I did try to work out from the code how the -map-mask thing worked,
but eventually gave up.

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