[v9,0/1] watchdog: aspeed: Revise handling of bootstatus

Message

PeterYin April 30, 2024, 2:31 p.m. UTC

Regarding the AST2600 specification, the WDTn Timeout Status Register
(WDT10) has bit 1 reserved. Bit 1 of the status register indicates
on ast2500 if the boot was from the second boot source.
It does not indicate that the most recent reset was triggered by
the watchdog. The code should just be changed to set WDIOF_CARDRESET
if bit 0 of the status register is set. However, this bit can be clear when
watchdog register 0x0c bit1(Reset System after timeout) is enabled.
Thereforce include SCU register to veriy WDIOF_EXTERN1 and WDIOF_CARDRESET
in ast2600 SCU74 or ast2400/ast2500 SCU3C.

Change Log:

v8 -> v9
   - Rename and restructure the SCU.

v7 -> v8
   - Simplify the code.

v6 -> v7
   - To use syscon_regmap_lookup_by_compatibleys to get scu base
   - Power on reset is set when triggered by AC or SRSRST.
     Thereforce, we clear flag to ensure next boot cause is a real watchdog case.
     We use the external reset flag to determine
     if it is an external reset or card reset.

v5 -> v6
  - Fixed missing WDT_TIMEOUT_STATUS_EVENT.

v4 -> v5
  - Revert indentation.

v3 -> v4
  - Add error handling for syscon_regmap_lookup_by_phandle and
  regmap_read.

v2 -> v3
  - Fixed WDIOF_CARDRESET status bit check and added support
  for WDIOF_EXTERN1 on ast2500 and ast2600.

v1 -> v2
  - Add comment and support WDIOF_CARDRESET in ast2600

v1
  - Patch 0001 - Add WDIOF_EXTERN1 bootstatus
---
 drivers/watchdog/aspeed_wdt.c | 90 +++++++++++++++++++++++++++++++----
 1 file changed, 82 insertions(+), 8 deletions(-)