driver/ddr/fsl: Update timing config for heavy load

In case four chip-selects are all active, the turnaround times need to
increase to avoid overlapping under heavy load.

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 99714bf..0bfcd34 100644 (file)
--- a/drivers/ddr/fsl/ctrl_regs.c
+++ b/drivers/ddr/fsl/ctrl_regs.c
@@ -317,7 +317,24 @@ static void set_timing_cfg_0(const unsigned int ctrl_num,
 
        /* for faster clock, need more time for data setup */
        trwt_mclk = (data_rate/1000000 > 1900) ? 3 : 2;
-       twrt_mclk = 1;
+
+       /*
+        * for single quad-rank DIMM and two-slot DIMMs
+        * to avoid ODT overlap
+        */
+       switch (avoid_odt_overlap(dimm_params)) {
+       case 2:
+               twrt_mclk = 2;
+               twwt_mclk = 2;
+               trrt_mclk = 2;
+               break;
+       default:
+               twrt_mclk = 1;
+               twwt_mclk = 1;
+               trrt_mclk = 0;
+               break;
+       }
+
        act_pd_exit_mclk = picos_to_mclk(ctrl_num, txp);
        pre_pd_exit_mclk = act_pd_exit_mclk;
        /*
@@ -1822,6 +1839,7 @@ static void set_timing_cfg_4(fsl_ddr_cfg_regs_t *ddr,
        unsigned int wrt = 0; /* Write-to-read turnaround for same CS */
        unsigned int rrt = 0; /* Read-to-read turnaround for same CS */
        unsigned int wwt = 0; /* Write-to-write turnaround for same CS */
+       unsigned int trwt_mclk = 0;     /* ext_rwt */
        unsigned int dll_lock = 0; /* DDR SDRAM DLL Lock Time */
 
 #if defined(CONFIG_SYS_FSL_DDR3) || defined(CONFIG_SYS_FSL_DDR4)
@@ -1835,17 +1853,21 @@ static void set_timing_cfg_4(fsl_ddr_cfg_regs_t *ddr,
                wwt = 2;        /* BL/2 + 2 clocks */
        }
 #endif
-
 #ifdef CONFIG_SYS_FSL_DDR4
        dll_lock = 2;   /* tDLLK = 1024 clocks */
 #elif defined(CONFIG_SYS_FSL_DDR3)
        dll_lock = 1;   /* tDLLK = 512 clocks from spec */
 #endif
+
+       if (popts->trwt_override)
+               trwt_mclk = popts->trwt;
+
        ddr->timing_cfg_4 = (0
                             | ((rwt & 0xf) << 28)
                             | ((wrt & 0xf) << 24)
                             | ((rrt & 0xf) << 20)
                             | ((wwt & 0xf) << 16)
+                            | ((trwt_mclk & 0xc) << 12)
                             | (dll_lock & 0x3)
                             );
        debug("FSLDDR: timing_cfg_4 = 0x%08x\n", ddr->timing_cfg_4);