In case the Device Tree blob passed by the boot agent supplies both an
'interrupts-extended' and an 'interrupts' property in order to allow for
older kernels to be usable, prefer the new-style 'interrupts-extended'
property which conveys a lot more information.

This allows us to have bootloaders willingly maintaining backwards
compatibility with older kernels without entirely deprecating the
'interrupts' property.

Update the bindings documentation to describe a situation where both the
'interrupts-extended' and the 'interrupts' property are present, and
which one takes precedence over the other.

Cc: stable@vger.kernel.org # 3.13+
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

The standard interrupts property in device tree can only handle
interrupts coming from a single interrupt parent. If a device is wired
to multiple interrupt controllers, then it needs to be attached to a
node with an interrupt-map property to demux the interrupt specifiers
which is confusing. It would be a lot easier if there was a form of the
interrupts property that allows for a separate interrupt phandle for
each interrupt specifier.

This patch does exactly that by creating a new interrupts-extended
property which reuses the phandle+arguments pattern used by GPIOs and
other core bindings.
Signed-off-by: NGrant Likely <grant.likely@linaro.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NKumar Gala <galak@codeaurora.org>
[grant.likely: removed versatile platform hunks into separate patch]
Cc: Rob Herring <rob.herring@calxeda.com>

In order to use a device as interrupt controller, it needs to be marked
with the DT interrupt-controller property. This commit adds rudimentary
documentation about the required standard properties and describes the
most commonly used interrupt specifiers.

Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: NStephen Warren <swarren@wwwdotorg.org>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: NRob Herring <rob.herring@calxeda.com>