drivers/ddr/fsl: Enable detection of one DDR controller operation for LSCH3

Freescale LSCH3 platforms use two DDR controlers interleaving mode out of
reset. It can be configured to disable one controller. To support this
operation, the driver needs to detect and skip the disabled controller.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/config.h b/arch/arm/include/asm/arch-fsl-layerscape/config.h
index 5ce916c..afc329a 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/config.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/config.h
@@ -67,6 +67,13 @@
 #define CCI_MN_DVM_DOMAIN_CTL		0x200
 #define CCI_MN_DVM_DOMAIN_CTL_SET	0x210
 
+#define CCI_HN_F_0_BASE			(CCI_MN_BASE + 0x200000)
+#define CCI_HN_F_1_BASE			(CCI_MN_BASE + 0x210000)
+#define CCN_HN_F_SAM_CTL		0x8	/* offset on base HN_F base */
+#define CCN_HN_F_SAM_NODEID_MASK	0x7f
+#define CCN_HN_F_SAM_NODEID_DDR0	0x4
+#define CCN_HN_F_SAM_NODEID_DDR1	0xe
+
 #define CCI_RN_I_0_BASE			(CCI_MN_BASE + 0x800000)
 #define CCI_RN_I_2_BASE			(CCI_MN_BASE + 0x820000)
 #define CCI_RN_I_6_BASE			(CCI_MN_BASE + 0x860000)
diff --git a/drivers/ddr/fsl/main.c b/drivers/ddr/fsl/main.c
index 72ec1be..c686632 100644
--- a/drivers/ddr/fsl/main.c
+++ b/drivers/ddr/fsl/main.c
@@ -813,6 +813,7 @@
 	info.board_need_mem_reset = board_need_mem_reset;
 	info.board_mem_reset = board_assert_mem_reset;
 	info.board_mem_de_reset = board_deassert_mem_reset;
+	remove_unused_controllers(&info);
 
 	return __fsl_ddr_sdram(&info);
 }
diff --git a/drivers/ddr/fsl/util.c b/drivers/ddr/fsl/util.c
index ce55aea..1a49b28 100644
--- a/drivers/ddr/fsl/util.c
+++ b/drivers/ddr/fsl/util.c
@@ -385,3 +385,43 @@
 		ddr_out32(ddrc_debug2_p[i], ddrc_debug2[i]);
 }
 #endif /* CONFIG_FSL_DDR_SYNC_REFRESH */
+
+void remove_unused_controllers(fsl_ddr_info_t *info)
+{
+#ifdef CONFIG_FSL_LSCH3
+	int i;
+	u64 nodeid;
+	void *hnf_sam_ctrl = (void *)(CCI_HN_F_0_BASE + CCN_HN_F_SAM_CTL);
+	bool ddr0_used = false;
+	bool ddr1_used = false;
+
+	for (i = 0; i < 8; i++) {
+		nodeid = in_le64(hnf_sam_ctrl) & CCN_HN_F_SAM_NODEID_MASK;
+		if (nodeid == CCN_HN_F_SAM_NODEID_DDR0) {
+			ddr0_used = true;
+		} else if (nodeid == CCN_HN_F_SAM_NODEID_DDR1) {
+			ddr1_used = true;
+		} else {
+			printf("Unknown nodeid in HN-F SAM control: 0x%llx\n",
+			       nodeid);
+		}
+		hnf_sam_ctrl += (CCI_HN_F_1_BASE - CCI_HN_F_0_BASE);
+	}
+	if (!ddr0_used && !ddr1_used) {
+		printf("Invalid configuration in HN-F SAM control\n");
+		return;
+	}
+
+	if (!ddr0_used && info->first_ctrl == 0) {
+		info->first_ctrl = 1;
+		info->num_ctrls = 1;
+		debug("First DDR controller disabled\n");
+		return;
+	}
+
+	if (!ddr1_used && info->first_ctrl + info->num_ctrls > 1) {
+		info->num_ctrls = 1;
+		debug("Second DDR controller disabled\n");
+	}
+#endif
+}
diff --git a/include/fsl_ddr.h b/include/fsl_ddr.h
index 1ac092b..9aaf6b3 100644
--- a/include/fsl_ddr.h
+++ b/include/fsl_ddr.h
@@ -131,6 +131,7 @@
 /* processor specific function */
 void fsl_ddr_set_memctl_regs(const fsl_ddr_cfg_regs_t *regs,
 				   unsigned int ctrl_num, int step);
+void remove_unused_controllers(fsl_ddr_info_t *info);
 
 /* board specific function */
 int fsl_ddr_get_dimm_params(dimm_params_t *pdimm,