diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-watchdog')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-watchdog | 82 |
1 files changed, 80 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-watchdog b/Documentation/ABI/testing/sysfs-class-watchdog index 736046b33040..70eabccf0557 100644 --- a/Documentation/ABI/testing/sysfs-class-watchdog +++ b/Documentation/ABI/testing/sysfs-class-watchdog @@ -6,6 +6,19 @@ Description: device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of ioctl interface. +What: /sys/class/watchdog/watchdogn/options +Date: April 2023 +Contact: Thomas Weißschuh +Description: + It is a read only file. It contains options of watchdog device. + +What: /sys/class/watchdog/watchdogn/fw_version +Date: April 2023 +Contact: Thomas Weißschuh +Description: + It is a read only file. It contains firmware version of + watchdog device. + What: /sys/class/watchdog/watchdogn/identity Date: August 2015 Contact: Wim Van Sebroeck <wim@iguana.be> @@ -17,8 +30,13 @@ What: /sys/class/watchdog/watchdogn/nowayout Date: August 2015 Contact: Wim Van Sebroeck <wim@iguana.be> Description: - It is a read only file. While reading, it gives '1' if that - device supports nowayout feature else, it gives '0'. + It is a read/write file. While reading, it gives '1' + if the device has the nowayout feature set, otherwise + it gives '0'. Writing a '1' to the file enables the + nowayout feature. Once set, the nowayout feature + cannot be disabled, so writing a '0' either has no + effect (if the feature was already disabled) or + results in a permission error. What: /sys/class/watchdog/watchdogn/state Date: August 2015 @@ -49,3 +67,63 @@ Contact: Wim Van Sebroeck <wim@iguana.be> Description: It is a read only file. It is read to know about current value of timeout programmed. + +What: /sys/class/watchdog/watchdogn/pretimeout +Date: December 2016 +Contact: Wim Van Sebroeck <wim@iguana.be> +Description: + It is a read only file. It specifies the time in seconds before + timeout when the pretimeout interrupt is delivered. Pretimeout + is an optional feature. + +What: /sys/class/watchdog/watchdogn/pretimeout_available_governors +Date: February 2017 +Contact: Wim Van Sebroeck <wim@iguana.be> +Description: + It is a read only file. It shows the pretimeout governors + available for this watchdog. + +What: /sys/class/watchdog/watchdogn/pretimeout_governor +Date: February 2017 +Contact: Wim Van Sebroeck <wim@iguana.be> +Description: + It is a read/write file. When read, the currently assigned + pretimeout governor is returned. When written, it sets + the pretimeout governor. + +What: /sys/class/watchdog/watchdog1/access_cs0 +Date: August 2019 +Contact: Ivan Mikhaylov <i.mikhaylov@yadro.com>, + Alexander Amelkin <a.amelkin@yadro.com> +Description: + It is a read/write file. This attribute exists only if the + system has booted from the alternate flash chip due to + expiration of a watchdog timer of AST2400/AST2500 when + alternate boot function was enabled with 'aspeed,alt-boot' + devicetree option for that watchdog or with an appropriate + h/w strapping (for WDT2 only). + + At alternate flash the 'access_cs0' sysfs node provides: + + ast2400: + a way to get access to the primary SPI flash + chip at CS0 after booting from the alternate + chip at CS1. + ast2500: + a way to restore the normal address mapping + from (CS0->CS1, CS1->CS0) to (CS0->CS0, + CS1->CS1). + + Clearing the boot code selection and timeout counter also + resets to the initial state the chip select line mapping. When + the SoC is in normal mapping state (i.e. booted from CS0), + clearing those bits does nothing for both versions of the SoC. + For alternate boot mode (booted from CS1 due to wdt2 + expiration) the behavior differs as described above. + + This option can be used with wdt2 (watchdog1) only. + + When read, the current status of the boot code selection is + shown. When written with any non-zero value, it clears + the boot code selection and the timeout counter, which results + in chipselect reset for AST2400/AST2500. |