powerpc/mpc85xx: Add workaround for DDR erratum A004934
After DDR controller is enabled, it performs a calibration for the
transmit data vs DQS paths. During this calibration, the DDR controller
may make an inaccurate calculation, resulting in a non-optimal tap point.
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/arch/powerpc/cpu/mpc85xx/ddr-gen3.c b/arch/powerpc/cpu/mpc85xx/ddr-gen3.c
index 8bed5fe..21840bf 100644
--- a/arch/powerpc/cpu/mpc85xx/ddr-gen3.c
+++ b/arch/powerpc/cpu/mpc85xx/ddr-gen3.c
@@ -140,6 +140,9 @@
out_be32(&ddr->debug[i], regs->debug[i]);
}
}
+#ifdef CONFIG_SYS_FSL_ERRATUM_A_004934
+ out_be32(&ddr->debug[28], 0x00003000);
+#endif
#ifdef CONFIG_SYS_FSL_ERRATUM_DDR_A003474
out_be32(&ddr->debug[12], 0x00000015);