Sequential accesses to non-existent memory must be synchronized,

at least on G2 cores.

This fixes get_ram_size() problems on MPC5200 Rev. B boards.

1 files changed, 19 insertions, 0 deletions

diff --git a/board/mcc200/mcc200.c b/board/mcc200/mcc200.c
index 71a691b5dbf..8b475c690d9 100644
--- a/board/mcc200/mcc200.c
+++ b/board/mcc200/mcc200.c
@@ -27,6 +27,7 @@
 #include <common.h>
 #include <mpc5xxx.h>
 #include <pci.h>
+#include <asm/processor.h>
 
 /* Two MT48LC8M32B2 for 32 MB */
 /* #include "mt48lc8m32b2-6-7.h" */
@@ -98,6 +99,7 @@ long int initdram (int board_type)
 {
 	ulong dramsize = 0;
 	ulong dramsize2 = 0;
+	uint svr, pvr;
 #ifndef CFG_RAMBOOT
 	ulong test1, test2;
 
@@ -192,6 +194,23 @@ long int initdram (int board_type)
 
 #endif /* CFG_RAMBOOT */
 
+	/*
+	 * On MPC5200B we need to set the special configuration delay in the
+	 * DDR controller. Please refer to Freescale's AN3221 "MPC5200B SDRAM
+	 * Initialization and Configuration", 3.3.1 SDelay--MBAR + 0x0190:
+	 *
+	 * "The SDelay should be written to a value of 0x00000004. It is
+	 * required to account for changes caused by normal wafer processing
+	 * parameters."
+	 */
+	svr = get_svr();
+	pvr = get_pvr();
+	if ((SVR_MJREV(svr) >= 2) && (PVR_MAJ(pvr) == 1) && 
+	    (PVR_MIN(pvr) == 4)) {
+		*(vu_long *)MPC5XXX_SDRAM_SDELAY = 0x04;
+		__asm__ volatile ("sync");
+	}
+
 	return dramsize + dramsize2;
 }