Changeset 2362

Timestamp:

Jul 14, 2011 8:14:19 AM (23 months ago)

Author:

wmb

Message:

OLPC XO-1.75 - RTC driver - force the Clock Halt bit off if necessary, and verify that it worked.

File:

• cpu/arm/olpc/1.75/rtc.fth (modified) (2 diffs)

cpu/arm/olpc/1.75/rtc.fth

@@ +1 @@
+purpose: Driver for external IDT1338 RTC chip on XO-1.75
+
 0 0  " "  " /" begin-package
 " rtc" name
@@ -21 +23 @@
 
 headers
-: open  ( -- true )
-   true
+: open  ( -- okay )
+   0 ['] rtc@ catch  if        ( x )
+      drop false  exit         ( -- false )
+   then                        ( value )
+
+   \ Ensure that the Clock Halt bit is off
+   dup h# 80 and  if           ( value )
+      \ Turn off Clock Halt
+      h# 7f and 0 rtc!         ( )
+      \ Verify that it went off
+      0 rtc@ h# 80 and         ( error? )
+      dup  if  ." RTC Clock Halt is stuck on" cr  then  ( error? )
+      0=                       ( okay? )
+   else                        ( value )
+      drop true                ( true )
+   then                        ( okay? )
 ;
 : close  ( -- )