powerpc/mpc8xxx: fix DDR data width checking

Checking width before setting DDR controller. SPD for DDR1 and DDR2 has
data width and primary sdram width. The latter one has different meaning
for DDR3.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/cpu/mpc8xxx/ddr/options.c

@@ -423,14 +423,33 @@ unsigned int populate_memctl_options(int all_DIMMs_registered,
 	 * presuming all dimms are similar
 	 * 0 = 64-bit, 1 = 32-bit, 2 = 16-bit
 	 */
-	if (pdimm[0].primary_sdram_width == 64)
-		popts->data_bus_width = 0;
-	else if (pdimm[0].primary_sdram_width == 32)
-		popts->data_bus_width = 1;
-	else if (pdimm[0].primary_sdram_width == 16)
-		popts->data_bus_width = 2;
-	else
-		panic("Error: invalid primary sdram width!\n");
+#if defined(CONFIG_FSL_DDR1) || defined(CONFIG_FSL_DDR2)
+	if (pdimm[0].n_ranks != 0) {
+		if ((pdimm[0].data_width >= 64) && \
+			(pdimm[0].data_width <= 72))
+			popts->data_bus_width = 0;
+		else if ((pdimm[0].data_width >= 32) || \
+			(pdimm[0].data_width <= 40))
+			popts->data_bus_width = 1;
+		else {
+			panic("Error: data width %u is invalid!\n",
+				pdimm[0].data_width);
+		}
+	}
+#else
+	if (pdimm[0].n_ranks != 0) {
+		if (pdimm[0].primary_sdram_width == 64)
+			popts->data_bus_width = 0;
+		else if (pdimm[0].primary_sdram_width == 32)
+			popts->data_bus_width = 1;
+		else if (pdimm[0].primary_sdram_width == 16)
+			popts->data_bus_width = 2;
+		else {
+			panic("Error: primary sdram width %u is invalid!\n",
+				pdimm[0].primary_sdram_width);
+		}
+	}
+#endif
 
 	/* Choose burst length. */
 #if defined(CONFIG_FSL_DDR3)