Introduction

This page describes the AXI WDT/Window watchdog driver which is available in mainline and Xilinx Linux distribution as
drivers/watchdog/of_xilinx_wdt.c

HW IP Features

Connects as a 32-bit slave on a AXI4-Lite interface
Watchdog timer with selectable timeout period and interrupt
Configurable WDT enable: enable-once or enable-repeatedly
One 32-bit free-running timebase counter with rollover interrupt-dual control register
Generic watchdog timer feature implemented.

Known Issues and Limitations

The current driver does not support the Axi Window watchdog feature.

Kernel Configuration

The following config options should be enabled in order to build the xilinx watchdog driver:
CONFIG_XILINX_WATCHDOG
CONFIG_WATCHDOG

¦ Symbol: XILINX_WATCHDOG [=y] ¦
¦ Type : tristate ¦
¦ Prompt: Xilinx Watchdog timer ¦
¦ Location: ¦
¦ -> Device Drivers ¦
¦ (4) -> Watchdog Timer Support (WATCHDOG [=y]) ¦
¦ Defined at drivers/watchdog/Kconfig:171 ¦
¦ Depends on: WATCHDOG [=y] && HAS_IOMEM [=y] ¦
¦ Selects: WATCHDOG_CORE [=y]

Devicetree

For more details, please refer
Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
Example:

watchdog {
 
        compatible = "xlnx,xps-timebase-wdt-1.0.a";
        reg = <0x42600000 0x1000>;
        xlnx-wdt-enable-once = <0>;
        xlnx-wdt-interval = <0x1b>;
};

Test procedure

Change the parameters using IOCTLs and see if reported values is correct.

# /bin/wdt_app /dev/watchdog1

Last boot is caused by : Power-On-Reset
The timeout was is 42 seconds
root@uart:~#

Mainline Status

This driver is currently in sync with the mainline kernel.

Change Log

2023.2
- Summary
  - watchdog: of_xilinx_wdt: Revert Versal WWDT support
  - watchdog: of_xilinx_wdt: Use devm_clk_get_enabled() helper
  - watchdog: of_xilinx_wdt: Remove unnecessary clock disable call in the remove path
- Commits
2023.1
- Summary
  - watchdog: of_xilinx_wdt: Update maximum timeout value based on ref clock
- Commits
  - 72a24cae
2022.2
- None
2022.1
- None

2021.2
- None

2021.1
- None
2020.2
- Summary
  - watchdog: of_xilinx_wdt: Initialize watchdog via data structure
  - watchdog: of_xilinx_wdt: Introduce wdttype enum for identification
  - watchdog: of_xilinx_wdt: Add Versal support
  - watchdog: of_xilinx_wdt: Wire setting up timeout via module parameter/DT
  - watchdog: of_xilinx_wdt: Add Versal Window watchdog support
- Commits

2020.1
- None
2019.2
- Summary
  - watchdog: of_xilinx_wdt: Fix Typo mistake in macro
  - watchdog: of_xilinx_wdt: Changed dev_err to dev_warn
- Commits
  - dc9c7a11 watchdog: of_xilinx_wdt: Fix Typo mistake in macro
  - 2291066b watchdog: of_xilinx_wdt: Changed dev_err to dev_warn
2019.1
- Summary
  - watchdog: of_xilinx_wdt: Add comment to spinlock
  - watchdog: of_xilinx_wdt: Used BIT macro
  - watchdog: of_xilinx_wdt: Used dev_dbg()
  - watchdog: of_xilinx_wdt: Initialize watchdog via data structure
  - watchdog: of_xilinx_wdt: Introduce wdttype enum for identification
  - watchdog: of_xilinx_wdt: Wire setting up timeout via module parameter/DT
- Commits
  - 685a0c8 watchdog: of_xilinx_wdt: Add comment to spinlock
  - 7c8ad55 watchdog: of_xilinx_wdt: Used BIT macro
  - fa1a0ce watchdog: of_xilinx_wdt: Fix Typo mistake in macro
  - f15a615 watchdog: of_xilinx_wdt: Used dev_dbg()
  - abd20c4 watchdog: of_xilinx_wdt: Initialize watchdog via data structure
  - d00b686 watchdog: of_xilinx_wdt: Introduce wdttype enum for identification
  - 594a62d watchdog: of_xilinx_wdt: Wire setting up timeout via module parameter/DT
2018.1
- Summary
  - watchdog: of_xilinx_wdt: Add support for reading freq via CCF
  - watchdog: of_xilinx_wdt: Add suspend/resume support
- Commits
  - b6bc416 watchdog: of_xilinx_wdt: Add support for reading freq via CCF
  - 6f671c6 watchdog: of_xilinx_wdt: Add suspend/resume support
2018.2
- None
2018.3
- None
2017.4
- None
2017.3
- None
2017.2
- None
2017.1
- Summary
  - watchdog: xilinx: Add clock support.
  - watchdog: of_xilinx_wdt: Add clock adaptation support.
- Commits
  - 9d6b4ef watchdog: xilinx: Add clock support.
  - 7f6adda watchdog: of_xilinx_wdt: Add clock adaptation support.
2016.4
- None
2016.3
- None