fsl/ddr: Add workaround for ERRATUM_A009942
During the receive data training, the DDRC may complete on a
non-optimal setting that could lead to data corruption or
initialization failure.
Workaround: before setting MEM_EN, set DEBUG_29 register with
specific value for different data rates.
Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/config.h b/arch/arm/include/asm/arch-fsl-layerscape/config.h
index 49b113d..83a207c 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/config.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/config.h
@@ -118,6 +118,7 @@
#define CONFIG_SYS_FSL_ERRATUM_A008585
#define CONFIG_SYS_FSL_ERRATUM_A008751
#define CONFIG_SYS_FSL_ERRATUM_A009635
+#define CONFIG_SYS_FSL_ERRATUM_A009942
#elif defined(CONFIG_LS1043A)
#define CONFIG_MAX_CPUS 4
#define CONFIG_SYS_CACHELINE_SIZE 64
diff --git a/drivers/ddr/fsl/fsl_ddr_gen4.c b/drivers/ddr/fsl/fsl_ddr_gen4.c
index 3fca5c2..0d9dd0b 100644
--- a/drivers/ddr/fsl/fsl_ddr_gen4.c
+++ b/drivers/ddr/fsl/fsl_ddr_gen4.c
@@ -55,6 +55,10 @@
u32 vref_seq2[3] = {0xc0, 0xf0, 0x70}; /* for range 2 */
u32 *vref_seq = vref_seq1;
#endif
+#ifdef CONFIG_SYS_FSL_ERRATUM_A009942
+ ulong ddr_freq;
+ u32 tmp;
+#endif
#ifdef CONFIG_FSL_DDR_BIST
u32 mtcr, err_detect, err_sbe;
u32 cs0_bnds, cs1_bnds, cs2_bnds, cs3_bnds, cs0_config;
@@ -227,6 +231,20 @@
ddr_out32(&ddr->debug[25], 0x9000);
}
#endif
+
+#ifdef CONFIG_SYS_FSL_ERRATUM_A009942
+ ddr_freq = get_ddr_freq(ctrl_num) / 1000000;
+ tmp = ddr_in32(&ddr->debug[28]);
+ if (ddr_freq <= 1333)
+ ddr_out32(&ddr->debug[28], tmp | 0x0080006a);
+ else if (ddr_freq <= 1600)
+ ddr_out32(&ddr->debug[28], tmp | 0x0070006f);
+ else if (ddr_freq <= 1867)
+ ddr_out32(&ddr->debug[28], tmp | 0x00700076);
+ else if (ddr_freq <= 2133)
+ ddr_out32(&ddr->debug[28], tmp | 0x0060007b);
+#endif
+
/*
* For RDIMMs, JEDEC spec requires clocks to be stable before reset is
* deasserted. Clocks start when any chip select is enabled and clock