summaryrefslogtreecommitdiff
path: root/Documentation/ABI
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-27 11:17:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-27 11:17:38 -0700
commit7bccb9f10c8f36ee791769b531ed4d28f6379aae (patch)
tree71984804c7c76fcb12c5209009facb27d5e9d431 /Documentation/ABI
parent289991ce1cac18e7cd489902986ef986baa49568 (diff)
parentca2fc5efffde5a3827adfb0ab6a51b6f1c64d5ff (diff)
Merge tag 'linux-watchdog-5.4-rc1' of git://www.linux-watchdog.org/linux-watchdog
Pull watchdog updates from Wim Van Sebroeck: - addition of AST2600, i.MX7ULP and F81803 watchdog support - removal of the w90x900 and ks8695 drivers - ziirave_wdt improvements - small fixes and improvements * tag 'linux-watchdog-5.4-rc1' of git://www.linux-watchdog.org/linux-watchdog: (51 commits) watchdog: f71808e_wdt: Add F81803 support watchdog: qcom: remove unnecessary variable from private storage watchdog: qcom: support pre-timeout when the bark irq is available watchdog: imx_sc: this patch just fixes whitespaces watchdog: apseed: Add access_cs0 option for alt-boot watchdog: aspeed: add support for dual boot watchdog: orion_wdt: use timer1 as a pretimeout watchdog: Add i.MX7ULP watchdog support dt-bindings: watchdog: Add i.MX7ULP bindings dt-bindings: watchdog: sun4i: Add the watchdog clock dt-bindings: watchdog: sun4i: Add the watchdog interrupts dt-bindings: watchdog: Convert Allwinner watchdog to a schema dt-bindings: watchdog: Add YAML schemas for the generic watchdog bindings watchdog: aspeed: Add support for AST2600 dt-bindings: watchdog: Add ast2600 compatible watchdog: ziirave_wdt: Update checked I2C functionality mask watchdog: ziirave_wdt: Drop ziirave_firm_write_block_data() watchdog: ziirave_wdt: Fix DOWNLOAD_START payload watchdog: ziirave_wdt: Drop status polling code watchdog: ziirave_wdt: Fix RESET_PROCESSOR payload ...
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-class-watchdog34
1 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-watchdog b/Documentation/ABI/testing/sysfs-class-watchdog
index 6317ade5ad19..675f9b537661 100644
--- a/Documentation/ABI/testing/sysfs-class-watchdog
+++ b/Documentation/ABI/testing/sysfs-class-watchdog
@@ -72,3 +72,37 @@ 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.