[PATCH v4 0/9] Watchdog support for Armada 375/38x SoC

[Ezequiel Garcia]

Fourth round of the patchset adding support for watchdog on Armada 375 and
Armada 38x SoCs.

The new Armada 375/385 SoCs have two registers for the watchdog RSTOUT:

 1. It has a dedicated register (similar to the one in A370/XP)
 2. Also has a bit in a shared RSTOUT register.

Therefore, in order to support this two-folded RSTOUT, we extend the 'reg'
property in the watchdog devicetree and require a new pair of cells to specify
the shared RSTOUT.

On the driver side, we need to implement per-SoC stop() and enabled()
functions. Such somewhat complex infrastructure is needed to ensure the driver
performs proper reset of the watchdog timer, by masking and disabling the
RSTOUT before the interrupt is enabled.

I've pushed a branch so people can test this easily, e.g. ensuring
no regressions on Dove, Kirkwood and A370/XP:

https://github.com/MISL-EBU-System-SW/mainline-public/tree/wdt_a385_a375_v4

Series based on today's mvebu for-next. Will send a rebased version on top of
v3.15-rc1. Tested on A375-DB, A385-DB, A370-RD and Dove Cubox.

Changes from v3:

  * Added orion_wdt_get_regs() to do the ioremap'ing (and region request
    for non-shared regions), as previously suggested by Guenter. The probe()
    function is a bit more readable after this.

Changes from v2:

  * Cleaned-up usage of atomic_io_modify(), using it only when needed.
    For instance, the RSTOUT dedicated register on Armada 370/375/380/XP
    can be safely access without any lock.

  * Use devm_ioremap_resource() for the non-shared registers. The shared
    registers need to use devm_ioremap(), which does not request the
    memory region.

Changes from v1:

  * Reworked entirely!

Ezequiel Garcia (9):
  watchdog: orion: Move the register ioremap'ing to its own function
  watchdog: orion: Introduce a SoC-specific RSTOUT mapping
  watchdog: orion: Remove unneeded atomic access
  watchdog: orion: Introduce per-SoC stop() function
  watchdog: orion: Introduce per-SoC enabled() function
  watchdog: orion: Add Armada 375/380 SoC support
  ARM: mvebu: Enable Armada 375 watchdog in the devicetree
  ARM: mvebu: Enable Armada 380/385 watchdog in the devicetree
  ARM: mvebu: Add A375/A380 watchdog binding documentation

 .../devicetree/bindings/watchdog/marvel.txt        |   7 +
 arch/arm/boot/dts/armada-375.dtsi                  |   6 +
 arch/arm/boot/dts/armada-38x.dtsi                  |   7 +
 drivers/watchdog/orion_wdt.c                       | 213 ++++++++++++++++++---
 4 files changed, 210 insertions(+), 23 deletions(-)

-- 
1.9.0