driver/ddr/fsl: Add support of overriding chip select write leveling

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>

diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c
index 5e0ee77e46c6d28b4c8913789da52bda018b163e..d9cac2296a20afc431dcefa64bba109cd7e6a250 100644 (file)
--- 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 7fb418744e0a32c55355f18c20fd6dbabd8501dc..6aa16b23ddc95f6df53077fd2c789141dee4eb19 100644 (file)
--- 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 e8a2db91cb7e115275ae13c70a498de4ee518239..987119b014ee513166fd4ba6cbaf47d405f2ef85 100644 (file)
--- 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;