[PATCH v2 4/4] dt-bindings/watchdog: Add access_cs0 option for alt-boot

[Ivan Mikhaylov]

The option for the ast2400/2500 to get access to CS0 at runtime.

Signed-off-by: Ivan Mikhaylov <i.mikhaylov at yadro.com>
---
 Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
index c5077a1f5cb3..023a9b578df6 100644
--- a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
@@ -34,6 +34,13 @@ Optional properties:
                 engine is responsible for this.
 
  - aspeed,alt-boot:    If property is present then boot from alternate block.
+                       At alternate side 'access_cs0' sysfs file 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).
+
  - aspeed,external-signal: If property is present then signal is sent to
 			external reset counter (only WDT1 and WDT2). If not
 			specified no external signal is sent.
-- 
2.20.1