[PATCH v5 0/6] ARM: mediatek: Add support for interrupt polarity

[Yingjoe Chen]

This series is 5th version of interrupt polarity support for MediaTek SoCs.
This is based on Jiang's hierarchy irqdomain p2v3 [1], which is based on 
v3.18-rc2, and my mediatek SoC basic support [2].

Besides changing base, this version addressed comments from Thomas and Marc
and also fix a bug on mt6589 reported by Matthias.

In Jiang's version of irq_create_of_mapping, if irqdomain is hierarchy, it
will not perform irq_find_mapping check and set_type. The outermost
irqdomain need to take care of that. Because we will have several different
outermost irqdomain in different ARM SoCs, this cause code duplication. I
moved them back to irq_create_of_mapping.

Simplified block diagram for interrupt on my system:

    +-------+      +-------+
 ---| SYSIRQ|------|ARM GIC|
 ---|       |------|       |
 ---|       |------|       |
 ---|       |------|       |
 ---|       |------|       |
    +-------+      +-------+

In device tree, interrupt-parent for other devices is sysirq, child of gic.
This describe HW better and allow device to specify polarity as it is sent
by the device.

When using hierarchy irq domain, gic will use irq_domain_add_linear to
create irqdomain and all interrupt numbers must come from device tree. My
/proc/interrupts looks like this now:

# cat /proc/interrupts
           CPU0
 16:     149578  MT_SYSIRQ 113  mtk_timer
 20:       1082  MT_SYSIRQ  54  serial

Changes in v5:
 - Fix bug on mt6589 reported by Matthias
 - Fix bug for irq_find_mapping in irq_create_of_mapping
 - Merge Marc's change to proper handle non-DT case in gic_init_bases

Changes in v4:
 - Discussed in [3]
 - Remove arm,hierarchy-irq-domain. When GIC is probed by DT, it will
support hierarchy irqdomain.

Changes in v3:
 - Discussed in [4]
 - First implementation using hierarchy irqdomain

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-October/297624.html
[2] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-October/296093.html
[3] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-October/296911.html
[4] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-October/293766.html


Yingjoe Chen (6):
  irqdomain: do irq_find_mapping and set_type for hierarchy irqdomain
  genirq: Add more helper functions to support stacked irq_chip
  irqchip: gic: Support hierarchy irq domain.
  ARM: mediatek: Add sysirq interrupt polarity support
  ARM: mediatek: Add sysirq in mt6589/mt8135/mt8127 dtsi
  dt-bindings: add bindings for mediatek sysirq

 .../bindings/arm/mediatek/mediatek,sysirq.txt      |  26 ++++
 arch/arm/boot/dts/mt6589.dtsi                      |  14 +-
 arch/arm/boot/dts/mt8127.dtsi                      |  14 +-
 arch/arm/boot/dts/mt8135.dtsi                      |  14 +-
 drivers/irqchip/Kconfig                            |   1 +
 drivers/irqchip/Makefile                           |   1 +
 drivers/irqchip/irq-gic.c                          |  90 +++++++----
 drivers/irqchip/irq-mtk-sysirq.c                   | 168 +++++++++++++++++++++
 include/linux/irq.h                                |   6 +
 kernel/irq/chip.c                                  |  28 ++++
 kernel/irq/irqdomain.c                             |  27 ++--
 11 files changed, 348 insertions(+), 41 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/mediatek/mediatek,sysirq.txt
 create mode 100644 drivers/irqchip/irq-mtk-sysirq.c