From 55c1284942b18cf83a297d33c8746aadcbf5f096 Mon Sep 17 00:00:00 2001
From: Steve Sakoman <steve@sakoman.com>
Date: Wed, 30 May 2012 07:38:07 +0000
Subject: [PATCH] omap: emif: deal with rams that return duplicate mr data on
all byte lanes
Some rams (Micron for example) return duplicate mr data on all byte lanes.
Users of the get_mr function currently don't deal with this duplicated
data gracefully. This patch detects the duplicated data and returns only
the expected 8 bit mr data.
Signed-off-by: Steve Sakoman <steve@sakoman.com>
---
arch/arm/cpu/armv7/omap-common/emif-common.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv7/omap-common/emif-common.c b/arch/arm/cpu/armv7/omap-common/emif-common.c
index 64427e61dad..61ade4c5987 100644
--- a/arch/arm/cpu/armv7/omap-common/emif-common.c
+++ b/arch/arm/cpu/armv7/omap-common/emif-common.c
@@ -77,7 +77,12 @@ static inline u32 get_mr(u32 base, u32 cs, u32 mr_addr)
mr = readl(&emif->emif_lpddr2_mode_reg_data);
debug("get_mr: EMIF%d cs %d mr %08x val 0x%x\n", emif_num(base),
cs, mr_addr, mr);
- return mr;
+ if (((mr & 0x0000ff00) >> 8) == (mr & 0xff) &&
+ ((mr & 0x00ff0000) >> 16) == (mr & 0xff) &&
+ ((mr & 0xff000000) >> 24) == (mr & 0xff))
+ return mr & 0xff;
+ else
+ return mr;
}
static inline void set_mr(u32 base, u32 cs, u32 mr_addr, u32 mr_val)
--
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