From: York Sun yorksun@freescale.com
JEDEC spec allows DRAM vendors to use prime DQ for write leveling. This is not an issue unless some DQ pins are not connected. If a platform uses regular DIMMs but with reduced DDR ECC pins, the prime DQ may end up on those floating pins for the second rank. The workaround is to use a known good chip select for this purpose.
Signed-off-by: York Sun yorksun@freescale.com --- Change log: v5: No change. v4: No change. v3: No change. v2: No change.
drivers/ddr/fsl/ctrl_regs.c | 3 +++ drivers/ddr/fsl/interactive.c | 2 ++ include/fsl_ddr_sdram.h | 2 ++ 3 files changed, 7 insertions(+)
diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c index 5e0ee77..d9cac22 100644 --- a/drivers/ddr/fsl/ctrl_regs.c +++ b/drivers/ddr/fsl/ctrl_regs.c @@ -2276,6 +2276,9 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts, if (ip_rev > 0x40400) unq_mrs_en = 1;
+ if (ip_rev > 0x40700) + ddr->debug[18] = popts->cswl_override; + set_ddr_sdram_cfg_2(ddr, popts, unq_mrs_en); set_ddr_sdram_mode(ddr, popts, common_dimm, cas_latency, additive_latency, unq_mrs_en); diff --git a/drivers/ddr/fsl/interactive.c b/drivers/ddr/fsl/interactive.c index 7fb4187..6aa16b2 100644 --- a/drivers/ddr/fsl/interactive.c +++ b/drivers/ddr/fsl/interactive.c @@ -511,6 +511,7 @@ static void fsl_ddr_options_edit(fsl_ddr_info_t *pinfo, CTRL_OPTIONS(wrlvl_override), CTRL_OPTIONS(wrlvl_sample), CTRL_OPTIONS(wrlvl_start), + CTRL_OPTIONS(cswl_override), CTRL_OPTIONS(rcw_override), CTRL_OPTIONS(rcw_1), CTRL_OPTIONS(rcw_2), @@ -801,6 +802,7 @@ static void print_memctl_options(const memctl_options_t *popts) CTRL_OPTIONS(wrlvl_override), CTRL_OPTIONS(wrlvl_sample), CTRL_OPTIONS(wrlvl_start), + CTRL_OPTIONS_HEX(cswl_override), CTRL_OPTIONS(rcw_override), CTRL_OPTIONS(rcw_1), CTRL_OPTIONS(rcw_2), diff --git a/include/fsl_ddr_sdram.h b/include/fsl_ddr_sdram.h index e8a2db9..987119b 100644 --- a/include/fsl_ddr_sdram.h +++ b/include/fsl_ddr_sdram.h @@ -281,6 +281,7 @@ typedef struct memctl_options_partial_s { #define DDR_DATA_BUS_WIDTH_64 0 #define DDR_DATA_BUS_WIDTH_32 1 #define DDR_DATA_BUS_WIDTH_16 2 +#define DDR_CSWL_CS0 0x04000001 /* * Generalized parameters for memory controller configuration, * might be a little specific to the FSL memory controller @@ -340,6 +341,7 @@ typedef struct memctl_options_s { unsigned int cpo_override; unsigned int write_data_delay; /* DQS adjust */
+ unsigned int cswl_override; unsigned int wrlvl_override; unsigned int wrlvl_sample; /* Write leveling */ unsigned int wrlvl_start;