mpc83xx: Rename CONFIG_SYS_DDR_CONFIG and cleanup DDR csbnds code

Rename CONFIG_SYS_DDR_CONFIG to include which CS it is configuring
Cleanup the setting of the csnbds to respect the setting of
CONFIG_SYS_DDR_SDRAM_BASE
Use __ilog2 instead of writing the code to compute it
Disable unused CS configs
Ensure ddrlaw.bar is configured

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/board/sbc8349/sbc8349.c b/board/sbc8349/sbc8349.c
index 50fae7c..42f4c1e 100644
--- a/board/sbc8349/sbc8349.c
+++ b/board/sbc8349/sbc8349.c
@@ -89,26 +89,25 @@
 int fixed_sdram(void)
 {
 	volatile immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
-	u32 msize = 0;
-	u32 ddr_size;
-	u32 ddr_size_log2;
+	u32 msize = CONFIG_SYS_DDR_SIZE;
+	u32 ddr_size = msize << 20;	/* DDR size in bytes */
+	u32 ddr_size_log2 = __ilog2(msize);
 
-	msize = CONFIG_SYS_DDR_SIZE;
-	for (ddr_size = msize << 20, ddr_size_log2 = 0;
-	     (ddr_size > 1);
-	     ddr_size = ddr_size>>1, ddr_size_log2++) {
-		if (ddr_size & 1) {
-			return -1;
-		}
-	}
 	im->sysconf.ddrlaw[0].bar = CONFIG_SYS_DDR_SDRAM_BASE & 0xfffff000;
 	im->sysconf.ddrlaw[0].ar = LAWAR_EN | ((ddr_size_log2 - 1) & LAWAR_SIZE);
 
 #if (CONFIG_SYS_DDR_SIZE != 256)
 #warning Currently any ddr size other than 256 is not supported
 #endif
-	im->ddr.csbnds[2].csbnds = 0x0000000f;
-	im->ddr.cs_config[2] = CONFIG_SYS_DDR_CONFIG;
+
+#if ((CONFIG_SYS_DDR_SDRAM_BASE & 0x00FFFFFF) != 0)
+#warning Chip select bounds is only configurable in 16MB increments
+#endif
+	im->ddr.csbnds[2].csbnds =
+		((CONFIG_SYS_DDR_SDRAM_BASE >> CSBNDS_SA_SHIFT) & CSBNDS_SA) |
+		(((CONFIG_SYS_DDR_SDRAM_BASE + ddr_size - 1) >>
+				CSBNDS_EA_SHIFT) & CSBNDS_EA);
+	im->ddr.cs_config[2] = CONFIG_SYS_DDR_CS2_CONFIG;
 
 	/* currently we use only one CS, so disable the other banks */
 	im->ddr.cs_config[0] = 0;