1What:		/sys/class/watchdog/watchdogn/bootstatus
  2Date:		August 2015
  3Contact:	Wim Van Sebroeck <wim@iguana.be>
  4Description:
  5		It is a read only file. It contains status of the watchdog
  6		device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of
  7		ioctl interface.
  8
  9What:		/sys/class/watchdog/watchdogn/identity
 10Date:		August 2015
 11Contact:	Wim Van Sebroeck <wim@iguana.be>
 12Description:
 13		It is a read only file. It contains identity string of
 14		watchdog device.
 15
 16What:		/sys/class/watchdog/watchdogn/nowayout
 17Date:		August 2015
 18Contact:	Wim Van Sebroeck <wim@iguana.be>
 19Description:
 20		It is a read/write file. While reading, it gives '1'
 21		if the device has the nowayout feature set, otherwise
 22		it gives '0'. Writing a '1' to the file enables the
 23		nowayout feature. Once set, the nowayout feature
 24		cannot be disabled, so writing a '0' either has no
 25		effect (if the feature was already disabled) or
 26		results in a permission error.
 27
 28What:		/sys/class/watchdog/watchdogn/state
 29Date:		August 2015
 30Contact:	Wim Van Sebroeck <wim@iguana.be>
 31Description:
 32		It is a read only file. It gives active/inactive status of
 33		watchdog device.
 34
 35What:		/sys/class/watchdog/watchdogn/status
 36Date:		August 2015
 37Contact:	Wim Van Sebroeck <wim@iguana.be>
 38Description:
 39		It is a read only file. It contains watchdog device's
 40		internal status bits. It is equivalent to WDIOC_GETSTATUS
 41		of ioctl interface.
 42
 43What:		/sys/class/watchdog/watchdogn/timeleft
 44Date:		August 2015
 45Contact:	Wim Van Sebroeck <wim@iguana.be>
 46Description:
 47		It is a read only file. It contains value of time left for
 48		reset generation. It is equivalent to WDIOC_GETTIMELEFT of
 49		ioctl interface.
 50
 51What:		/sys/class/watchdog/watchdogn/timeout
 52Date:		August 2015
 53Contact:	Wim Van Sebroeck <wim@iguana.be>
 54Description:
 55		It is a read only file. It is read to know about current
 56		value of timeout programmed.
 57
 58What:		/sys/class/watchdog/watchdogn/pretimeout
 59Date:		December 2016
 60Contact:	Wim Van Sebroeck <wim@iguana.be>
 61Description:
 62		It is a read only file. It specifies the time in seconds before
 63		timeout when the pretimeout interrupt is delivered.  Pretimeout
 64		is an optional feature.
 65
 66What:		/sys/class/watchdog/watchdogn/pretimeout_avaialable_governors
 67Date:		February 2017
 68Contact:	Wim Van Sebroeck <wim@iguana.be>
 69Description:
 70		It is a read only file. It shows the pretimeout governors
 71		available for this watchdog.
 72
 73What:		/sys/class/watchdog/watchdogn/pretimeout_governor
 74Date:		February 2017
 75Contact:	Wim Van Sebroeck <wim@iguana.be>
 76Description:
 77		It is a read/write file. When read, the currently assigned
 78		pretimeout governor is returned.  When written, it sets
 79		the pretimeout governor.
 80
 81What:		/sys/class/watchdog/watchdog1/access_cs0
 82Date:		August 2019
 83Contact:	Ivan Mikhaylov <i.mikhaylov@yadro.com>,
 84		Alexander Amelkin <a.amelkin@yadro.com>
 85Description:
 86		It is a read/write file. This attribute exists only if the
 87		system has booted from the alternate flash chip due to
 88		expiration of a watchdog timer of AST2400/AST2500 when
 89		alternate boot function was enabled with 'aspeed,alt-boot'
 90		devicetree option for that watchdog or with an appropriate
 91		h/w strapping (for WDT2 only).
 92
 93		At alternate flash the 'access_cs0' sysfs node provides:
 94
 95			ast2400:
 96				a way to get access to the primary SPI flash
 97				chip at CS0 after booting from the alternate
 98				chip at CS1.
 99			ast2500:
100				a way to restore the normal address mapping
101				from (CS0->CS1, CS1->CS0) to (CS0->CS0,
102				CS1->CS1).
103
104		Clearing the boot code selection and timeout counter also
105		resets to the initial state the chip select line mapping. When
106		the SoC is in normal mapping state (i.e. booted from CS0),
107		clearing those bits does nothing for both versions of the SoC.
108		For alternate boot mode (booted from CS1 due to wdt2
109		expiration) the behavior differs as described above.
110
111		This option can be used with wdt2 (watchdog1) only.
112
113		When read, the current status of the boot code selection is
114		shown. When written with any non-zero value, it clears
115		the boot code selection and the timeout counter, which results
116		in chipselect reset for AST2400/AST2500.