ARM: am33xx: Inhibit re-initialization of DDR during RTC-only

[J-u-boot.git] / arch / arm / mach-omap2 / am33xx / board.c

diff --git a/arch/arm/mach-omap2/am33xx/board.c b/arch/arm/mach-omap2/am33xx/board.c
index ef1de1a115b7507a8fb882846f0735c1ee903bd8..e1d4ddb44b7bca2e9840c0e216ab587b0cb5080d 100644 (file)
--- a/arch/arm/mach-omap2/am33xx/board.c
+++ b/arch/arm/mach-omap2/am33xx/board.c
@@ -376,6 +376,9 @@ static void watchdog_disable(void)
 static void rtc_only(void)
 {
        struct davinci_rtc *rtc = (struct davinci_rtc *)RTC_BASE;
+       struct prm_device_inst *prm_device =
+                               (struct prm_device_inst *)PRM_DEVICE_INST;
+
        u32 scratch1;
        void (*resume_func)(void);
 
@@ -403,9 +406,20 @@ static void rtc_only(void)
         */
        rtc_only_update_board_type(scratch1 >> RTC_BOARD_TYPE_SHIFT);
 
+       /*
+        * Enable EMIF_DEVOFF in PRCM_PRM_EMIF_CTRL to indicate to EMIF we
+        * are resuming from self-refresh. This avoids an unnecessary re-init
+        * of the DDR. The re-init takes time and we would need to wait for
+        * it to complete before accessing DDR to avoid L3 NOC errors.
+        */
+       writel(EMIF_CTRL_DEVOFF, &prm_device->emif_ctrl);
+
        rtc_only_prcm_init();
        sdram_init();
 
+       /* Disable EMIF_DEVOFF for normal operation and to exit self-refresh */
+       writel(0, &prm_device->emif_ctrl);
+
        resume_func = (void *)readl(&rtc->scratch0);
        if (resume_func)
                resume_func();