From: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
Work around for Errata ID: i632 "LPDDR2 Corruption After OFF Mode
Transition When CS1 Is Used On EMIF" which impacts OMAP443x silicon
The issue occurs when EMIF_SDRAM_CONFIG is restored first before
EMIF_SDRAM_CONFIG_2 is not yet restored, the register configuration
is not set properly, we apply the required workaround allowing
the restore sequence to work properly.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
[t-kristo@xxxxxx: moved workaround from omap-sar.c to pm44xx.c]
Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
---
.../include/mach/ctrl_module_wkup_44xx.h | 2 +
arch/arm/mach-omap2/pm44xx.c | 37 ++++++++++++++++++++
2 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h b/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h
index a0af9ba..b763a79 100644
--- a/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h
+++ b/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h
@@ -28,6 +28,8 @@
#define OMAP4_CTRL_MODULE_WKUP_IP_REVISION 0x0000
#define OMAP4_CTRL_MODULE_WKUP_IP_HWINFO 0x0004
#define OMAP4_CTRL_MODULE_WKUP_IP_SYSCONFIG 0x0010
+#define OMAP4_CTRL_SECURE_EMIF1_SDRAM_CONFIG2_REG 0x0114
+#define OMAP4_CTRL_SECURE_EMIF2_SDRAM_CONFIG2_REG 0x011c
#define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_0 0x0460
#define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_1 0x0464
#define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_2 0x0468
diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
index 215b80e..dfaa254 100644
--- a/arch/arm/mach-omap2/pm44xx.c
+++ b/arch/arm/mach-omap2/pm44xx.c
@@ -17,12 +17,18 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <asm/system_misc.h>
+#include <linux/io.h>
+
+#include <mach/ctrl_module_wkup_44xx.h>
+#include <mach/hardware.h>
#include "common.h"
#include "clockdomain.h"
#include "powerdomain.h"
#include "pm.h"
+#define EMIF_SDRAM_CONFIG2_OFFSET 0xc
+
struct power_state {
struct powerdomain *pwrdm;
u32 next_state;
@@ -215,6 +221,37 @@ static int __init omap4_pm_init(void)
pr_err("Power Management for TI OMAP4.\n");
+ /*
+ * Work around for OMAP443x Errata i632: "LPDDR2 Corruption After OFF
+ * Mode Transition When CS1 Is Used On EMIF":
+ * Overwrite EMIF1/EMIF2
+ * SECURE_EMIF1_SDRAM_CONFIG2_REG
+ * SECURE_EMIF2_SDRAM_CONFIG2_REG
+ */
+ if (cpu_is_omap443x()) {
+ void __iomem *secure_ctrl_mod;
+ void __iomem *emif1;
+ void __iomem *emif2;
+ u32 val;
+
+ secure_ctrl_mod = ioremap(OMAP4_CTRL_MODULE_WKUP, SZ_4K);
+ emif1 = ioremap(OMAP44XX_EMIF1_BASE, SZ_1M);
+ emif2 = ioremap(OMAP44XX_EMIF2_BASE, SZ_1M);
+
+ BUG_ON(!secure_ctrl_mod || !emif1 || !emif2);
+
+ val = __raw_readl(emif1 + EMIF_SDRAM_CONFIG2_OFFSET);
+ __raw_writel(val, secure_ctrl_mod +
+ OMAP4_CTRL_SECURE_EMIF1_SDRAM_CONFIG2_REG);
+ val = __raw_readl(emif2 + EMIF_SDRAM_CONFIG2_OFFSET);
+ __raw_writel(val, secure_ctrl_mod +
+ OMAP4_CTRL_SECURE_EMIF2_SDRAM_CONFIG2_REG);
+ wmb();
+ iounmap(secure_ctrl_mod);
+ iounmap(emif1);
+ iounmap(emif2);
+ }
+
ret = pwrdm_for_each(pwrdms_setup, NULL);
if (ret) {
pr_err("Failed to setup powerdomains\n");
--
1.7.4.1
--
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