[PATCH v1 1/2] mx6: ddr: Fix disabling on-die termination

[Francesco Dolcini]

In case rtt_nom is set to 0 keep ODT disabled (MMDC MPODTCTRL = 0).
No changes required for DDR MR1 Rtt_Nom impedance register, 0 value is
already handled correctly.

No board is currently affected by this change (rtt_nom != 0 on all i.MX6
ddr3 boards), this will be used by a follow-up change.

Fixes: fe0f7f7842e1 ("mx6: add mmdc configuration for MX6Q/MX6DL")
Signed-off-by: Francesco Dolcini <francesco.dolcini at toradex.com>
---
 arch/arm/mach-imx/mx6/ddr.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-imx/mx6/ddr.c b/arch/arm/mach-imx/mx6/ddr.c
index 73a637c42d6c..3c87c577737b 100644
--- a/arch/arm/mach-imx/mx6/ddr.c
+++ b/arch/arm/mach-imx/mx6/ddr.c
@@ -1469,8 +1469,17 @@ void mx6_ddr3_cfg(const struct mx6_ddr_sysinfo *sysinfo,
 		MMDC1(mprddqby3dl, 0x33333333);
 	}
 
-	/* MMDC Termination: rtt_nom:2 RZQ/2(120ohm), rtt_nom:1 RZQ/4(60ohm) */
-	val = (sysinfo->rtt_nom == 2) ? 0x00011117 : 0x00022227;
+	/*
+	 * MMDC Termination: rtt_nom:2 RZQ/2(120ohm),
+	 *                   rtt_nom:1 RZQ/4(60ohm),
+	 *                   rtt_nom:0 Disabled
+	 */
+	if (sysinfo->rtt_nom == 0)
+		val = 0x00000000;
+	else if (sysinfo->rtt_nom == 2)
+		val = 0x00011117;
+	else
+		val = 0x00022227;
 	mmdc0->mpodtctrl = val;
 	if (sysinfo->dsize > 1)
 		MMDC1(mpodtctrl, val);
-- 
2.25.1