xref: /openbmc/linux/Documentation/ABI/testing/sysfs-class-watchdog (revision b852e7a4a9ab6a1fb08c5aa36b1043672fd814dc)
133b71126SPratyush AnandWhat:		/sys/class/watchdog/watchdogn/bootstatus
233b71126SPratyush AnandDate:		August 2015
333b71126SPratyush AnandContact:	Wim Van Sebroeck <wim@iguana.be>
433b71126SPratyush AnandDescription:
533b71126SPratyush Anand		It is a read only file. It contains status of the watchdog
633b71126SPratyush Anand		device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of
733b71126SPratyush Anand		ioctl interface.
833b71126SPratyush Anand
9*b852e7a4SThomas WeißschuhWhat:		/sys/class/watchdog/watchdogn/fw_version
10*b852e7a4SThomas WeißschuhDate:		April 2023
11*b852e7a4SThomas WeißschuhContact:	Thomas Weißschuh
12*b852e7a4SThomas WeißschuhDescription:
13*b852e7a4SThomas Weißschuh		It is a read only file. It contains firmware version of
14*b852e7a4SThomas Weißschuh		watchdog device.
15*b852e7a4SThomas Weißschuh
1633b71126SPratyush AnandWhat:		/sys/class/watchdog/watchdogn/identity
1733b71126SPratyush AnandDate:		August 2015
1833b71126SPratyush AnandContact:	Wim Van Sebroeck <wim@iguana.be>
1933b71126SPratyush AnandDescription:
2033b71126SPratyush Anand		It is a read only file. It contains identity string of
2133b71126SPratyush Anand		watchdog device.
2233b71126SPratyush Anand
2333b71126SPratyush AnandWhat:		/sys/class/watchdog/watchdogn/nowayout
2433b71126SPratyush AnandDate:		August 2015
2533b71126SPratyush AnandContact:	Wim Van Sebroeck <wim@iguana.be>
2633b71126SPratyush AnandDescription:
27bc44fa73SRasmus Villemoes		It is a read/write file. While reading, it gives '1'
28bc44fa73SRasmus Villemoes		if the device has the nowayout feature set, otherwise
29bc44fa73SRasmus Villemoes		it gives '0'. Writing a '1' to the file enables the
30bc44fa73SRasmus Villemoes		nowayout feature. Once set, the nowayout feature
31bc44fa73SRasmus Villemoes		cannot be disabled, so writing a '0' either has no
32bc44fa73SRasmus Villemoes		effect (if the feature was already disabled) or
33bc44fa73SRasmus Villemoes		results in a permission error.
3433b71126SPratyush Anand
3533b71126SPratyush AnandWhat:		/sys/class/watchdog/watchdogn/state
3633b71126SPratyush AnandDate:		August 2015
3733b71126SPratyush AnandContact:	Wim Van Sebroeck <wim@iguana.be>
3833b71126SPratyush AnandDescription:
3933b71126SPratyush Anand		It is a read only file. It gives active/inactive status of
4033b71126SPratyush Anand		watchdog device.
4133b71126SPratyush Anand
4233b71126SPratyush AnandWhat:		/sys/class/watchdog/watchdogn/status
4333b71126SPratyush AnandDate:		August 2015
4433b71126SPratyush AnandContact:	Wim Van Sebroeck <wim@iguana.be>
4533b71126SPratyush AnandDescription:
4633b71126SPratyush Anand		It is a read only file. It contains watchdog device's
4733b71126SPratyush Anand		internal status bits. It is equivalent to WDIOC_GETSTATUS
4833b71126SPratyush Anand		of ioctl interface.
4933b71126SPratyush Anand
5033b71126SPratyush AnandWhat:		/sys/class/watchdog/watchdogn/timeleft
5133b71126SPratyush AnandDate:		August 2015
5233b71126SPratyush AnandContact:	Wim Van Sebroeck <wim@iguana.be>
5333b71126SPratyush AnandDescription:
5433b71126SPratyush Anand		It is a read only file. It contains value of time left for
5533b71126SPratyush Anand		reset generation. It is equivalent to WDIOC_GETTIMELEFT of
5633b71126SPratyush Anand		ioctl interface.
5733b71126SPratyush Anand
5833b71126SPratyush AnandWhat:		/sys/class/watchdog/watchdogn/timeout
5933b71126SPratyush AnandDate:		August 2015
6033b71126SPratyush AnandContact:	Wim Van Sebroeck <wim@iguana.be>
6133b71126SPratyush AnandDescription:
6233b71126SPratyush Anand		It is a read only file. It is read to know about current
6333b71126SPratyush Anand		value of timeout programmed.
64d02d104eSJerry Hoemann
65d02d104eSJerry HoemannWhat:		/sys/class/watchdog/watchdogn/pretimeout
66d02d104eSJerry HoemannDate:		December 2016
67d02d104eSJerry HoemannContact:	Wim Van Sebroeck <wim@iguana.be>
68d02d104eSJerry HoemannDescription:
69d02d104eSJerry Hoemann		It is a read only file. It specifies the time in seconds before
70d02d104eSJerry Hoemann		timeout when the pretimeout interrupt is delivered.  Pretimeout
71d02d104eSJerry Hoemann		is an optional feature.
72d02d104eSJerry Hoemann
73d02d104eSJerry HoemannWhat:		/sys/class/watchdog/watchdogn/pretimeout_avaialable_governors
74d02d104eSJerry HoemannDate:		February 2017
75d02d104eSJerry HoemannContact:	Wim Van Sebroeck <wim@iguana.be>
76d02d104eSJerry HoemannDescription:
77d02d104eSJerry Hoemann		It is a read only file. It shows the pretimeout governors
78d02d104eSJerry Hoemann		available for this watchdog.
79d02d104eSJerry Hoemann
80d02d104eSJerry HoemannWhat:		/sys/class/watchdog/watchdogn/pretimeout_governor
81d02d104eSJerry HoemannDate:		February 2017
82d02d104eSJerry HoemannContact:	Wim Van Sebroeck <wim@iguana.be>
83d02d104eSJerry HoemannDescription:
84d02d104eSJerry Hoemann		It is a read/write file. When read, the currently assigned
85d02d104eSJerry Hoemann		pretimeout governor is returned.  When written, it sets
86d02d104eSJerry Hoemann		the pretimeout governor.
87ebdc0f58SIvan Mikhaylov
88ebdc0f58SIvan MikhaylovWhat:		/sys/class/watchdog/watchdog1/access_cs0
89ebdc0f58SIvan MikhaylovDate:		August 2019
90ebdc0f58SIvan MikhaylovContact:	Ivan Mikhaylov <i.mikhaylov@yadro.com>,
91ebdc0f58SIvan Mikhaylov		Alexander Amelkin <a.amelkin@yadro.com>
92ebdc0f58SIvan MikhaylovDescription:
93ebdc0f58SIvan Mikhaylov		It is a read/write file. This attribute exists only if the
94ebdc0f58SIvan Mikhaylov		system has booted from the alternate flash chip due to
95ebdc0f58SIvan Mikhaylov		expiration of a watchdog timer of AST2400/AST2500 when
96ebdc0f58SIvan Mikhaylov		alternate boot function was enabled with 'aspeed,alt-boot'
97ebdc0f58SIvan Mikhaylov		devicetree option for that watchdog or with an appropriate
98ebdc0f58SIvan Mikhaylov		h/w strapping (for WDT2 only).
99ebdc0f58SIvan Mikhaylov
100ebdc0f58SIvan Mikhaylov		At alternate flash the 'access_cs0' sysfs node provides:
10154a19b4dSMauro Carvalho Chehab
10254a19b4dSMauro Carvalho Chehab			ast2400:
10354a19b4dSMauro Carvalho Chehab				a way to get access to the primary SPI flash
104ebdc0f58SIvan Mikhaylov				chip at CS0 after booting from the alternate
105ebdc0f58SIvan Mikhaylov				chip at CS1.
10654a19b4dSMauro Carvalho Chehab			ast2500:
10754a19b4dSMauro Carvalho Chehab				a way to restore the normal address mapping
108ebdc0f58SIvan Mikhaylov				from (CS0->CS1, CS1->CS0) to (CS0->CS0,
109ebdc0f58SIvan Mikhaylov				CS1->CS1).
110ebdc0f58SIvan Mikhaylov
111ebdc0f58SIvan Mikhaylov		Clearing the boot code selection and timeout counter also
112ebdc0f58SIvan Mikhaylov		resets to the initial state the chip select line mapping. When
113ebdc0f58SIvan Mikhaylov		the SoC is in normal mapping state (i.e. booted from CS0),
114ebdc0f58SIvan Mikhaylov		clearing those bits does nothing for both versions of the SoC.
115ebdc0f58SIvan Mikhaylov		For alternate boot mode (booted from CS1 due to wdt2
116ebdc0f58SIvan Mikhaylov		expiration) the behavior differs as described above.
117ebdc0f58SIvan Mikhaylov
118ebdc0f58SIvan Mikhaylov		This option can be used with wdt2 (watchdog1) only.
119ebdc0f58SIvan Mikhaylov
120ebdc0f58SIvan Mikhaylov		When read, the current status of the boot code selection is
121ebdc0f58SIvan Mikhaylov		shown. When written with any non-zero value, it clears
122ebdc0f58SIvan Mikhaylov		the boot code selection and the timeout counter, which results
123ebdc0f58SIvan Mikhaylov		in chipselect reset for AST2400/AST2500.
124