WDOG: Output status on read

[Javinator9889]

Summary

Currently, the read function of the watchdog device is dummy and does nothing. Although this is fine, it's not useful at all from a userspace perspective, where you may want to check the current WDOG status.

A wrapper around the ioctl WDIOC_GETSTATUS has been added as the read function for the WDOG.

Impact

This should help debugging and developers with watchdog-enabled systems

Testing

The testing in this case is quite straightforward: cat /dev/watchdog0, whose output was:

nsh> cat /dev/watchdog0
Status       :
  flags      : 0x00000000
  timeout    : 30000
  timeleft   : 2947

[github-actions]

MemBrowse Memory Report

arduino-mega2560

• flash: .text +116 B (+0.2%, 67,430 B / 262,144 B, total: 26% used)

esp32-devkitc

• ROM: .flash.rodata +160 B, .flash.text +1,464 B (+1.3%, 124,372 B / 4,194,272 B, total: 3% used)
• drom0_0_seg: .flash.rodata +160 B (+1.2%, 13,456 B / 4,194,272 B, total: 0% used)
• irom0_0_seg: .flash.text +1,464 B (+1.7%, 88,580 B / 3,342,304 B, total: 3% used)

hifive1-revb

• flash: .text +120 B (+0.1%, 83,352 B / 4,194,304 B, total: 2% used)

mirtoo

• kseg0_progmem: .text +244 B (+0.4%, 67,436 B / 131,072 B, total: 51% used)

qemu-armv8a

• Code: .rodata +152 B, .text.dir_ioctl +64 B, .text.file_mq_vopen +40 B, .text.inode_checkopenperm +8 B, .text.nsh_session +8 B, .text.readline_common +816 B, .text.syslog_write_foreach -4 B (+0.9%, 318,122 B)
• Data: +8 B (+0.0%, 76,970 B)

qemu-intel64

• Code: .text +2,572 B (+0.0%, 8,658,048 B)
• Data: .rodata +224 B (+0.2%, 120,647 B)

rx65n-rsk2mb

• RAM: .bss +16 B (+0.2%, 6,586 B / 262,144 B, total: 3% used)
• ROM: .rodata +104 B, .text +1,440 B (+1.8%, 87,248 B / 2,097,152 B, total: 4% used)

s698pm-dkit

• Code: .text +5,040 B (+1.4%, 363,248 B)

stm32-nucleo-f103rb

• flash: .text +124 B (+0.4%, 33,928 B / 131,072 B, total: 26% used)

[xiaoxiang781216]

@Javinator9889 please squash your change into one patch.

[Javinator9889]

@xiaoxiang781216 squashed and force-pushed

[acassis]

@Javinator9889 please Document this new feature here: https://nuttx.apache.org/docs/latest/components/drivers/character/timers/watchdog.html

[Javinator9889]

@Javinator9889 please Document this new feature here: https://nuttx.apache.org/docs/latest/components/drivers/character/timers/watchdog.html

@acassis done at cd13c0c

[Javinator9889]

@xiaoxiang781216 @jerpelea waiting for your code-owners approval :)