[U-Boot] [PATCH 3/9] powerpc/mpc8548: Add workaround for erratum NMG_DDR120

Zhao Chenhui
2011-09-13T07:15:25Z

From: chenhui zhao <chenhui.zhao@freescale.com>

Erratum NMG_DDR120 (DDR19 in MPC8548 errata document) applies to some
early version silicons. The default settings of the DDR IO receiver
biasing may not work at cold temperature. When a failure occurs,
a DDR input latches an incorrect value. The workaround will set the
receiver to an acceptable bias point.

Signed-off-by: Gong Chen <g.chen@freescale.com>
Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
---
arch/powerpc/cpu/mpc85xx/cmd_errata.c | 4 ++++
arch/powerpc/cpu/mpc85xx/ddr-gen2.c | 22 +++++++++++++++++++++-
arch/powerpc/include/asm/config_mpc85xx.h | 1 +
3 files changed, 26 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/cpu/mpc85xx/cmd_errata.c b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
index 0478ec1..f0fa0f5 100644
--- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c
+++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
@@ -96,6 +96,10 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
#ifdef CONFIG_SYS_FSL_ERRATUM_IFC_A003399
puts("Work-around for Erratum IFC A-003399 enabled\n");
#endif
+#ifdef CONFIG_SYS_FSL_ERRATUM_NMG_DDR120
+ if ((SVR_MAJ(svr) == 1) || IS_SVR_REV(svr, 2, 0))
+ puts("Work-around for Erratum NMG DDR120 enabled\n");
+#endif
return 0;
}

diff --git a/arch/powerpc/cpu/mpc85xx/ddr-gen2.c b/arch/powerpc/cpu/mpc85xx/ddr-gen2.c
index 655f99c..a71fb42 100644
--- a/arch/powerpc/cpu/mpc85xx/ddr-gen2.c
+++ b/arch/powerpc/cpu/mpc85xx/ddr-gen2.c
@@ -1,5 +1,5 @@
/*
- * Copyright 2008 Freescale Semiconductor, Inc.
+ * Copyright 2008, 2011 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -8,6 +8,7 @@

#include <common.h>
#include <asm/io.h>
+#include <asm/processor.h>
#include <asm/fsl_ddr_sdram.h>

#if (CONFIG_CHIP_SELECTS_PER_CTRL > 4)
@@ -19,12 +20,31 @@ void fsl_ddr_set_memctl_regs(const fsl_ddr_cfg_regs_t *regs,
{
unsigned int i;
volatile ccsr_ddr_t *ddr = (void *)CONFIG_SYS_MPC85xx_DDR_ADDR;
+#ifdef CONFIG_SYS_FSL_ERRATUM_NMG_DDR120
+ ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
+ uint svr;
+#endif

if (ctrl_num) {
printf("%s unexpected ctrl_num = %u\n", __FUNCTION__, ctrl_num);
return;
}

+#ifdef CONFIG_SYS_FSL_ERRATUM_NMG_DDR120
+ /*
+ * Set the DDR IO receiver to an acceptable bias point.
+ * Fixed in Rev 2.1.
+ */
+ svr = get_svr();
+ if ((SVR_MAJ(svr) == 1) || IS_SVR_REV(svr, 2, 0)) {
+ if ((regs->ddr_sdram_cfg & SDRAM_CFG_SDRAM_TYPE_MASK) ==
+ SDRAM_CFG_SDRAM_TYPE_DDR2)
+ out_be32(&gur->ddrioovcr, 0x90000000);
+ else
+ out_be32(&gur->ddrioovcr, 0xA8000000);
+ }
+#endif
+
for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
if (i == 0) {
out_be32(&ddr->cs0_bnds, regs->cs[i].bnds);
diff --git a/arch/powerpc/include/asm/config_mpc85xx.h b/arch/powerpc/include/asm/config_mpc85xx.h
index f9bf80d..a0a12b2 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -62,6 +62,7 @@
#define CONFIG_SYS_FSL_NUM_LAWS 10
#define CONFIG_SYS_FSL_SEC_COMPAT 2
#define CONFIG_SYS_CCSRBAR_DEFAULT 0xff700000
+#define CONFIG_SYS_FSL_ERRATUM_NMG_DDR120

#elif defined(CONFIG_MPC8555)
#define CONFIG_MAX_CPUS 1
--
1.6.4.1