1 What: /sys/class/watchdog/watchdogn/ 1 What: /sys/class/watchdog/watchdogn/bootstatus
2 Date: August 2015 2 Date: August 2015
3 Contact: Wim Van Sebroeck <wim@iguana.be 3 Contact: Wim Van Sebroeck <wim@iguana.be>
4 Description: 4 Description:
5 It is a read only file. It con 5 It is a read only file. It contains status of the watchdog
6 device at boot. It is equivale 6 device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of
7 ioctl interface. 7 ioctl interface.
8 8
9 What: /sys/class/watchdog/watchdogn/ <<
10 Date: April 2023 <<
11 Contact: Thomas Weißschuh <<
12 Description: <<
13 It is a read only file. It con <<
14 <<
15 What: /sys/class/watchdog/watchdogn/ <<
16 Date: April 2023 <<
17 Contact: Thomas Weißschuh <<
18 Description: <<
19 It is a read only file. It con <<
20 watchdog device. <<
21 <<
22 What: /sys/class/watchdog/watchdogn/ 9 What: /sys/class/watchdog/watchdogn/identity
23 Date: August 2015 10 Date: August 2015
24 Contact: Wim Van Sebroeck <wim@iguana.be 11 Contact: Wim Van Sebroeck <wim@iguana.be>
25 Description: 12 Description:
26 It is a read only file. It con 13 It is a read only file. It contains identity string of
27 watchdog device. 14 watchdog device.
28 15
29 What: /sys/class/watchdog/watchdogn/ 16 What: /sys/class/watchdog/watchdogn/nowayout
30 Date: August 2015 17 Date: August 2015
31 Contact: Wim Van Sebroeck <wim@iguana.be 18 Contact: Wim Van Sebroeck <wim@iguana.be>
32 Description: 19 Description:
33 It is a read/write file. While 20 It is a read/write file. While reading, it gives '1'
34 if the device has the nowayout 21 if the device has the nowayout feature set, otherwise
35 it gives '0'. Writing a '1' to 22 it gives '0'. Writing a '1' to the file enables the
36 nowayout feature. Once set, th 23 nowayout feature. Once set, the nowayout feature
37 cannot be disabled, so writing 24 cannot be disabled, so writing a '0' either has no
38 effect (if the feature was alr 25 effect (if the feature was already disabled) or
39 results in a permission error. 26 results in a permission error.
40 27
41 What: /sys/class/watchdog/watchdogn/ 28 What: /sys/class/watchdog/watchdogn/state
42 Date: August 2015 29 Date: August 2015
43 Contact: Wim Van Sebroeck <wim@iguana.be 30 Contact: Wim Van Sebroeck <wim@iguana.be>
44 Description: 31 Description:
45 It is a read only file. It giv 32 It is a read only file. It gives active/inactive status of
46 watchdog device. 33 watchdog device.
47 34
48 What: /sys/class/watchdog/watchdogn/ 35 What: /sys/class/watchdog/watchdogn/status
49 Date: August 2015 36 Date: August 2015
50 Contact: Wim Van Sebroeck <wim@iguana.be 37 Contact: Wim Van Sebroeck <wim@iguana.be>
51 Description: 38 Description:
52 It is a read only file. It con 39 It is a read only file. It contains watchdog device's
53 internal status bits. It is eq 40 internal status bits. It is equivalent to WDIOC_GETSTATUS
54 of ioctl interface. 41 of ioctl interface.
55 42
56 What: /sys/class/watchdog/watchdogn/ 43 What: /sys/class/watchdog/watchdogn/timeleft
57 Date: August 2015 44 Date: August 2015
58 Contact: Wim Van Sebroeck <wim@iguana.be 45 Contact: Wim Van Sebroeck <wim@iguana.be>
59 Description: 46 Description:
60 It is a read only file. It con 47 It is a read only file. It contains value of time left for
61 reset generation. It is equiva 48 reset generation. It is equivalent to WDIOC_GETTIMELEFT of
62 ioctl interface. 49 ioctl interface.
63 50
64 What: /sys/class/watchdog/watchdogn/ 51 What: /sys/class/watchdog/watchdogn/timeout
65 Date: August 2015 52 Date: August 2015
66 Contact: Wim Van Sebroeck <wim@iguana.be 53 Contact: Wim Van Sebroeck <wim@iguana.be>
67 Description: 54 Description:
68 It is a read only file. It is 55 It is a read only file. It is read to know about current
69 value of timeout programmed. 56 value of timeout programmed.
70 57
71 What: /sys/class/watchdog/watchdogn/ 58 What: /sys/class/watchdog/watchdogn/pretimeout
72 Date: December 2016 59 Date: December 2016
73 Contact: Wim Van Sebroeck <wim@iguana.be 60 Contact: Wim Van Sebroeck <wim@iguana.be>
74 Description: 61 Description:
75 It is a read only file. It spe 62 It is a read only file. It specifies the time in seconds before
76 timeout when the pretimeout in 63 timeout when the pretimeout interrupt is delivered. Pretimeout
77 is an optional feature. 64 is an optional feature.
78 65
79 What: /sys/class/watchdog/watchdogn/ 66 What: /sys/class/watchdog/watchdogn/pretimeout_avaialable_governors
80 Date: February 2017 67 Date: February 2017
81 Contact: Wim Van Sebroeck <wim@iguana.be 68 Contact: Wim Van Sebroeck <wim@iguana.be>
82 Description: 69 Description:
83 It is a read only file. It sho 70 It is a read only file. It shows the pretimeout governors
84 available for this watchdog. 71 available for this watchdog.
85 72
86 What: /sys/class/watchdog/watchdogn/ 73 What: /sys/class/watchdog/watchdogn/pretimeout_governor
87 Date: February 2017 74 Date: February 2017
88 Contact: Wim Van Sebroeck <wim@iguana.be 75 Contact: Wim Van Sebroeck <wim@iguana.be>
89 Description: 76 Description:
90 It is a read/write file. When 77 It is a read/write file. When read, the currently assigned
91 pretimeout governor is returne 78 pretimeout governor is returned. When written, it sets
92 the pretimeout governor. 79 the pretimeout governor.
93 80
94 What: /sys/class/watchdog/watchdog1/ 81 What: /sys/class/watchdog/watchdog1/access_cs0
95 Date: August 2019 82 Date: August 2019
96 Contact: Ivan Mikhaylov <i.mikhaylov@yad 83 Contact: Ivan Mikhaylov <i.mikhaylov@yadro.com>,
97 Alexander Amelkin <a.amelkin@ya 84 Alexander Amelkin <a.amelkin@yadro.com>
98 Description: 85 Description:
99 It is a read/write file. This 86 It is a read/write file. This attribute exists only if the
100 system has booted from the alt 87 system has booted from the alternate flash chip due to
101 expiration of a watchdog timer 88 expiration of a watchdog timer of AST2400/AST2500 when
102 alternate boot function was en 89 alternate boot function was enabled with 'aspeed,alt-boot'
103 devicetree option for that wat 90 devicetree option for that watchdog or with an appropriate
104 h/w strapping (for WDT2 only). 91 h/w strapping (for WDT2 only).
105 92
106 At alternate flash the 'access 93 At alternate flash the 'access_cs0' sysfs node provides:
107 !! 94 ast2400: a way to get access to the primary SPI flash
108 ast2400: <<
109 a way to get a <<
110 chip at CS0 af 95 chip at CS0 after booting from the alternate
111 chip at CS1. 96 chip at CS1.
112 ast2500: !! 97 ast2500: a way to restore the normal address mapping
113 a way to resto <<
114 from (CS0->CS1 98 from (CS0->CS1, CS1->CS0) to (CS0->CS0,
115 CS1->CS1). 99 CS1->CS1).
116 100
117 Clearing the boot code selecti 101 Clearing the boot code selection and timeout counter also
118 resets to the initial state th 102 resets to the initial state the chip select line mapping. When
119 the SoC is in normal mapping s 103 the SoC is in normal mapping state (i.e. booted from CS0),
120 clearing those bits does nothi 104 clearing those bits does nothing for both versions of the SoC.
121 For alternate boot mode (boote 105 For alternate boot mode (booted from CS1 due to wdt2
122 expiration) the behavior diffe 106 expiration) the behavior differs as described above.
123 107
124 This option can be used with w 108 This option can be used with wdt2 (watchdog1) only.
125 109
126 When read, the current status 110 When read, the current status of the boot code selection is
127 shown. When written with any n 111 shown. When written with any non-zero value, it clears
128 the boot code selection and th 112 the boot code selection and the timeout counter, which results
129 in chipselect reset for AST240 113 in chipselect reset for AST2400/AST2500.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.