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authorYork Sun <yorksun@freescale.com>2014-12-02 11:18:09 -0800
committerYork Sun <yorksun@freescale.com>2014-12-15 09:15:12 -0800
commit938bbb6013f051808c08204184e94d0cdcb6dbff (patch)
tree8102d1ed2cb0ef18f642c606d4ade71219c62f64
parent84d13c58104ea121a8d38a1d9c71e404d8666875 (diff)
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driver/ddr/fsl: Fix MRC_CYC calculation for DDR3
For DDR controller version 4.7 or newer, MRC_CYC (mode register set cycle time) is max(tMRD, tMOD). tMRD is 4nCK, or 8nCK (RDIMM). tMOD is max(12nCK, 15ns) according to JEDEC spec. DDR4 is not affected by this change. Signed-off-by: York Sun <yorksun@freescale.com>
-rw-r--r--drivers/ddr/fsl/ctrl_regs.c21
1 files changed, 20 insertions, 1 deletions
diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c
index fe8aa98..03d7ff1 100644
--- a/drivers/ddr/fsl/ctrl_regs.c
+++ b/drivers/ddr/fsl/ctrl_regs.c
@@ -324,6 +324,7 @@ static void set_timing_cfg_0(fsl_ddr_cfg_regs_t *ddr,
#elif defined(CONFIG_SYS_FSL_DDR3)
unsigned int data_rate = get_ddr_freq(0);
int txp;
+ unsigned int ip_rev;
int odt_overlap;
/*
* (tXARD and tXARDS). Empirical?
@@ -336,7 +337,25 @@ static void set_timing_cfg_0(fsl_ddr_cfg_regs_t *ddr,
*/
txp = max((int)mclk_ps * 3, (mclk_ps > 1540 ? 7500 : 6000));
- tmrd_mclk = 4;
+ ip_rev = fsl_ddr_get_version();
+ if (ip_rev >= 0x40700) {
+ /*
+ * MRS_CYC = max(tMRD, tMOD)
+ * tMRD = 4nCK (8nCK for RDIMM)
+ * tMOD = max(12nCK, 15ns)
+ */
+ tmrd_mclk = max((unsigned int)12, picos_to_mclk(15000));
+ } else {
+ /*
+ * MRS_CYC = tMRD
+ * tMRD = 4nCK (8nCK for RDIMM)
+ */
+ if (popts->registered_dimm_en)
+ tmrd_mclk = 8;
+ else
+ tmrd_mclk = 4;
+ }
+
/* set the turnaround time */
/*