r1496 - cpu/x86/pc/olpc/via

Author: wmb
Date: 2009-11-21 04:40:50 +0100 (Sat, 21 Nov 2009)
New Revision: 1496

Modified:
   cpu/x86/pc/olpc/via/demodram.fth
   cpu/x86/pc/olpc/via/dramtiming.fth
   cpu/x86/pc/olpc/via/startdraminit.fth
Log:
OLPC trac 9727 - Made the DRAM CAS latency setting dependent on memory ID0
strapping, to support new DRAM chips that require CL=4.

Modified: cpu/x86/pc/olpc/via/demodram.fth
===================================================================
--- cpu/x86/pc/olpc/via/demodram.fth	2009-11-21 03:38:43 UTC (rev 1495)
+++ cpu/x86/pc/olpc/via/demodram.fth	2009-11-21 03:40:50 UTC (rev 1496)
@@ -53,7 +53,6 @@

\  61 ff 12 mreg  \ Trfc, Trrd  Trfc = 0x39+8 = 65  Trrd=4T ceil(7.5ns/5ns)

-   62 07  TCL  2 -              mreg   \ CL 3
    62 08  08                    mreg   \ 8-bank timing constraint
 \ !!!
    62 f0  Tras ns>tck 5 - 4 <<  mreg   \ Tras: ceil( 40.00/5) = 8     - 5 = 0x03
@@ -77,6 +76,17 @@
 [then]
    end-table

+   acpi-io-base 48 + port-rl  h# 0008.0000 # ax and  0<>  if  \ Memory ID0 bit - set for CL4 SDRAM
+      0 3 devfunc
+      62 07  4    2 -              mreg   \ CL 4
+      end-table
+   else
+      0 3 devfunc
+      62 07  3    2 -              mreg   \ CL 3
+      end-table
+   then
+
+
 \  DRAMBurstLength
    0 3 devfunc
    6c 08 08 mreg  \ Burst length 8

Modified: cpu/x86/pc/olpc/via/dramtiming.fth
===================================================================
--- cpu/x86/pc/olpc/via/dramtiming.fth	2009-11-21 03:38:43 UTC (rev 1495)
+++ cpu/x86/pc/olpc/via/dramtiming.fth	2009-11-21 03:40:50 UTC (rev 1496)
@@ -36,7 +36,9 @@
 d# 125.00 constant Trfc  \ Fudged to get same setting as Phoenix
 d#   7.50 constant Trrd
 \ d#  10.00 constant Trrd
-d#      3 constant TCL
+\ TCL depends on the type of RAM chip, so it is set dynamically
+\ d#      3 constant TCL \ Normal value
+\ d#      4 constant TCL \ For new RAM chips
 \ d#  40.00 constant Tras
  d#  45.00 constant Tras
 d#  15.00 constant Twr
@@ -95,3 +97,15 @@
 ;

: dblfudge32  2/  ;
+
+0 [if]
+: mrs-value  ( -- n )
+   3               \ code for burst length 8; use 2 for burst length 4
+   1    3 lshift or   \ Interleaved bursts
+   TCL  4 lshift or   \ CAS Latency
+   0    7 lshift or   \ Normal mode, not test mode
+   0    8 lshift or   \ Not DLL reset
+   Twr Tck / 1-  scramble-mrs  or   \ Twr cycles minus 1
+   3 lshift
+;
+[then]

Modified: cpu/x86/pc/olpc/via/startdraminit.fth
===================================================================
--- cpu/x86/pc/olpc/via/startdraminit.fth	2009-11-21 03:38:43 UTC (rev 1495)
+++ cpu/x86/pc/olpc/via/startdraminit.fth	2009-11-21 03:40:50 UTC (rev 1496)
@@ -24,8 +24,13 @@

13 36b config-wb  \ SDRAM MRS Enable
 \  101258 #) ax mov  \ Depends on Twr, CL, and Burst Length
-   1021d8 #) ax mov  \ Depends on Twr, CL, and Burst Length

+   acpi-io-base 48 + port-rl  h# 0008.0000 # ax and  0<>  if  \ Memory ID0 bit - set for CL4 SDRAM
+      102258 #) ax mov  \ Depends on Twr, CL, and Burst Length - CL4
+   else
+      1021d8 #) ax mov  \ Depends on Twr, CL, and Burst Length - CL3
+   then
+
 0 [if]
 2024b
 011 BL 8