powerpc/mpc8xxx: Fix DDR driver handling quad-rank DIMMs and address calculation

Fix handling quad-rank DIMMs in a system with two DIMM slots and first
slot supports both dual-rank DIMM and quad-rank DIMM.

For systems with quad-rank DIMM and double dual-rank DIMMs, cs_config
registers need to be enabled to maintain proper ODT operation. The
inactive CS should have bnds registers cleared.

Fix the turnaround timing for systems with all chip-selects enabled. This
wasn't an issue before because DDR was running lower than 1600MT/s with
this interleaving mode.

Fix DDR address calculation. It wasn't an issue until we have multiple
controllers with each more than 4GB and interleaving is disabled.

It also fixes the message of DDR: 2 GiB (DDR3, 64-bit, CL=0.5, ECC off)
when debugging DDR and first DDR controller is disabled. With the fix,
the first enabled controller information will be displayed.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>

1 files changed, 48 insertions, 14 deletions

diff --git a/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c b/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c
index c28f9cd201..5928eb8806 100644
--- a/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c
+++ b/arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c
@@ -229,6 +229,26 @@ static void set_csn_config_2(int i, fsl_ddr_cfg_regs_t *ddr)
 /* -3E = 667 CL5, -25 = CL6 800, -25E = CL5 800 */
 
 #if !defined(CONFIG_FSL_DDR1)
+static inline int avoid_odt_overlap(const dimm_params_t *dimm_params)
+{
+#if CONFIG_DIMM_SLOTS_PER_CTLR == 1
+	if (dimm_params[0].n_ranks == 4)
+		return 1;
+#endif
+
+#if CONFIG_DIMM_SLOTS_PER_CTLR == 2
+	if ((dimm_params[0].n_ranks == 2) &&
+		(dimm_params[1].n_ranks == 2))
+		return 1;
+
+#ifdef CONFIG_FSL_DDR_FIRST_SLOT_QUAD_CAPABLE
+	if (dimm_params[0].n_ranks == 4)
+		return 1;
+#endif
+#endif
+	return 0;
+}
+
 /*
  * DDR SDRAM Timing Configuration 0 (TIMING_CFG_0)
  *
@@ -236,7 +256,8 @@ static void set_csn_config_2(int i, fsl_ddr_cfg_regs_t *ddr)
  * dreams up non-zero default values to be backwards compatible.
  */
 static void set_timing_cfg_0(fsl_ddr_cfg_regs_t *ddr,
-				const memctl_options_t *popts)
+				const memctl_options_t *popts,
+				const dimm_params_t *dimm_params)
 {
 	unsigned char trwt_mclk = 0;   /* Read-to-write turnaround */
 	unsigned char twrt_mclk = 0;   /* Write-to-read turnaround */
@@ -266,7 +287,18 @@ static void set_timing_cfg_0(fsl_ddr_cfg_regs_t *ddr,
 	unsigned int data_rate = get_ddr_freq(0);
 	tmrd_mclk = 4;
 	/* set the turnaround time */
-	trwt_mclk = 1;
+
+	/*
+	 * for single quad-rank DIMM and two dual-rank DIMMs
+	 * to avoid ODT overlap
+	 */
+	if (avoid_odt_overlap(dimm_params)) {
+		twwt_mclk = 2;
+		trrt_mclk = 1;
+	}
+	/* for faster clock, need more time for data setup */
+	trwt_mclk = (data_rate/1000000 > 1800) ? 2 : 1;
+
 	if ((data_rate/1000000 > 1150) || (popts->memctl_interleaving))
 		twrt_mclk = 1;
 
@@ -1483,7 +1515,7 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
 				break;
 			}
 			sa = common_dimm->base_address;
-			ea = common_dimm->total_mem - 1;
+			ea = sa + common_dimm->total_mem - 1;
 		} else if (!popts->memctl_interleaving) {
 			/*
 			 * If memory interleaving between controllers is NOT
@@ -1497,7 +1529,7 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
 			switch (popts->ba_intlv_ctl & FSL_DDR_CS0_CS1_CS2_CS3) {
 			case FSL_DDR_CS0_CS1_CS2_CS3:
 				sa = common_dimm->base_address;
-				ea = common_dimm->total_mem - 1;
+				ea = sa + common_dimm->total_mem - 1;
 				break;
 			case FSL_DDR_CS0_CS1_AND_CS2_CS3:
 				if ((i >= 2) && (dimm_number == 0)) {
@@ -1554,17 +1586,19 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
 		sa >>= 24;
 		ea >>= 24;
 
-		ddr->cs[i].bnds = (0
-			| ((sa & 0xFFF) << 16)	/* starting address MSB */
-			| ((ea & 0xFFF) << 0)	/* ending address MSB */
-			);
+		if (cs_en) {
+			ddr->cs[i].bnds = (0
+				| ((sa & 0xFFF) << 16)/* starting address MSB */
+				| ((ea & 0xFFF) << 0)	/* ending address MSB */
+				);
+		} else {
+			debug("FSLDDR: setting bnds to 0 for inactive CS\n");
+			ddr->cs[i].bnds = 0;
+		}
 
 		debug("FSLDDR: cs[%d]_bnds = 0x%08x\n", i, ddr->cs[i].bnds);
-		if (cs_en) {
-			set_csn_config(dimm_number, i, ddr, popts, dimm_params);
-			set_csn_config_2(i, ddr);
-		} else
-			debug("CS%d is disabled.\n", i);
+		set_csn_config(dimm_number, i, ddr, popts, dimm_params);
+		set_csn_config_2(i, ddr);
 	}
 
 	/*
@@ -1577,7 +1611,7 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
 	set_ddr_eor(ddr, popts);
 
 #if !defined(CONFIG_FSL_DDR1)
-	set_timing_cfg_0(ddr, popts);
+	set_timing_cfg_0(ddr, popts, dimm_params);
 #endif
 
 	set_timing_cfg_3(ddr, popts, common_dimm, cas_latency);