[U-Boot] [PATCH 1/3] mx6: ddr: allow 32 cycles for DQS gating calibration
Eric Nelson
eric at nelint.com
Sun Oct 30 18:19:00 CET 2016
The DDR calibration code is only setting flag DG_CMP_CYC (DQS gating sample
cycle) for the first PHY.
Set the 32-cycle flag for both PHYs and clear when done so the MPDGCTRL0
output value isn't polluted with calibration artifacts.
Signed-off-by: Eric Nelson <eric at nelint.com>
---
arch/arm/cpu/armv7/mx6/ddr.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/arm/cpu/armv7/mx6/ddr.c b/arch/arm/cpu/armv7/mx6/ddr.c
index 7beb7ea..b15f376 100644
--- a/arch/arm/cpu/armv7/mx6/ddr.c
+++ b/arch/arm/cpu/armv7/mx6/ddr.c
@@ -347,6 +347,8 @@ int mmdc_do_dqs_calibration(void)
* 16 before comparing read data.
*/
setbits_le32(&mmdc0->mpdgctrl0, 1 << 30);
+ if (sysinfo->dsize == 2)
+ setbits_le32(&mmdc1->mpdgctrl0, 1 << 30);
/* Set bit 28 to start automatic read DQS gating calibration */
setbits_le32(&mmdc0->mpdgctrl0, 5 << 28);
@@ -365,6 +367,11 @@ int mmdc_do_dqs_calibration(void)
if ((bus_size == 0x2) && (readl(&mmdc1->mpdgctrl0) & 0x00001000))
errors |= 2;
+ /* now disable mpdgctrl0[DG_CMP_CYC] */
+ clrbits_le32(&mmdc0->mpdgctrl0, 1 << 30);
+ if (sysinfo->dsize == 2)
+ clrbits_le32(&mmdc1->mpdgctrl0, 1 << 30);
+
/*
* DQS gating absolute offset should be modified from
* reflecting (HW_DG_LOWx + HW_DG_UPx)/2 to
--
2.7.4
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