[U-Boot] [PATCH] omap: emif: configure emif only when required

[Lokesh Vutla]

DMM_LISA_MAP registers program whether memory is mapped
on particular EMIF or not. Irrespective of these registers
EMIF is getting configured. Correcting the same.

Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
---
 arch/arm/cpu/armv7/omap-common/emif-common.c |   39 ++++++++++++++++++++++----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/armv7/omap-common/emif-common.c b/arch/arm/cpu/armv7/omap-common/emif-common.c
index 30dcf1b..179525f 100644
--- a/arch/arm/cpu/armv7/omap-common/emif-common.c
+++ b/arch/arm/cpu/armv7/omap-common/emif-common.c
@@ -33,6 +33,8 @@
 #include <asm/utils.h>
 #include <linux/compiler.h>
 
+static int emif1_enabled = -1, emif2_enabled = -1;
+
 void set_lpmode_selfrefresh(u32 base)
 {
 	struct emif_reg_struct *emif = (struct emif_reg_struct *)base;
@@ -1218,6 +1220,27 @@ void dmm_init(u32 base)
 	}
 }
 
+static void enable_emifs(void)
+{
+	u32 i, section, valid;
+
+	emif1_enabled = 0;
+	emif2_enabled = 0;
+	for (i = 0; i < 4; i++) {
+		section	= __raw_readl(DMM_BASE + i*4);
+		valid = (section & EMIF_SDRC_MAP_MASK) >>
+			(EMIF_SDRC_MAP_SHIFT);
+		if (valid == 1) {
+			emif1_enabled = 1;
+		} else if (valid == 2) {
+			emif2_enabled = 1;
+		} else if (valid == 3) {
+			emif1_enabled = 1;
+			emif2_enabled = 1;
+			return;
+		}
+	}
+}
 /*
  * SDRAM initialization:
  * SDRAM initialization has two parts:
@@ -1255,15 +1278,21 @@ void sdram_init(void)
 			writel(CM_DLL_CTRL_NO_OVERRIDE, &prcm->cm_dll_ctrl);
 	}
 
-	do_sdram_init(EMIF1_BASE);
-	do_sdram_init(EMIF2_BASE);
-
 	if (!in_sdram)
 		dmm_init(DMM_BASE);
 
+	enable_emifs();
+	if (emif1_enabled)
+		do_sdram_init(EMIF1_BASE);
+
+	if (emif2_enabled)
+		do_sdram_init(EMIF2_BASE);
+
 	if (!(in_sdram || warm_reset())) {
-		emif_post_init_config(EMIF1_BASE);
-		emif_post_init_config(EMIF2_BASE);
+		if (emif1_enabled)
+			emif_post_init_config(EMIF1_BASE);
+		if (emif2_enabled)
+			emif_post_init_config(EMIF2_BASE);
 	}
 
 	/* for the shadow registers to take effect */
-- 
1.7.9.5