On Fri, May 05, 2017 at 03:32:59PM -0400, Sebastien Bourdelin wrote:

This watchdog is instantiated in a FPGA and can only be access using a
GPIOs bit-banged bus, called the NBUS by Technologic Systems.
The watchdog is made of only one register, called the feed register.
Writing to this register will re-arm the watchdog for a given time (and
enable it if it was disable). It can be disabled by writing a special
value into it.

Signed-off-by: Sebastien Bourdelin <redacted>
---
Changes v2 -> v3:
  - rebase on master
  - remove the timeout table to simplify the logic (suggested by
  Guenter Roeck)
  - fix the set_timeout function (suggested by Guenter Roeck)
  - hardcode the max_hw_heartbeat_ms value based on the ts4600 max
  timeout value supported (suggested by Guenter Roeck)
  - remove the max_timeout usage and set a default timeout value
(suggested by Guenter Roeck)
  - use the devm_watchdog_register_device function instead of
  watchdog_register_device (suggested by Guenter Roeck)

Changes v1 -> v2:
  - rebase on master
  - retrieve the ts_nbus instantiated by the parent node (suggested by
  Linus Walleij)
  - rename the wdt by watchdog in the device tree and in the
  documentation (suggested by Rob Herring)
  - add a dependency to the TS_NBUS driver in the Kconfig (suggested by
  Guenter Roeck)
  - simplify the set_timeout function (suggested by Guenter Roeck)
  - use the max_hw_heartbeat_ms callback instead of the max_timeout
  callback (suggested by Guenter Roeck)
---
 .../devicetree/bindings/watchdog/ts4600-wdt.txt    |  16 ++
 arch/arm/boot/dts/imx28-ts4600-common.dtsi         |   5 +

The dts change shouldn't be mixed within driver patch.

Shawn

 drivers/watchdog/Kconfig                           |  11 ++
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/ts4600_wdt.c                      | 185 +++++++++++++++++++++
 5 files changed, 218 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/ts4600-wdt.txt
 create mode 100644 drivers/watchdog/ts4600_wdt.c