blackfin: scb: Add system crossbar init code.

If SCB exists in select blackfin cpu, developer can change the SCB
priority in kernel configuration.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Steven Miao <realmz6@gmail.com>

arch/blackfin/include/asm/scb.h

@@ -0,0 +1,21 @@
+/*
+ * arch/blackfin/mach-common/scb-init.c - reprogram system cross bar priority
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#define SCB_SLOT_OFFSET	24
+#define SCB_MI_MAX_SLOT 32
+
+struct scb_mi_prio {
+	unsigned long scb_mi_arbr;
+	unsigned long scb_mi_arbw;
+	unsigned char scb_mi_slots;
+	unsigned char scb_mi_prio[SCB_MI_MAX_SLOT];
+};
+
+extern struct scb_mi_prio scb_data[];
+
+extern void init_scb(void);

arch/blackfin/kernel/setup.c

@@ -35,6 +35,9 @@
 #ifdef CONFIG_BF60x
 #include <mach/pm.h>
 #endif
+#ifdef CONFIG_SCB_PRIORITY
+#include <asm/scb.h>
+#endif
 
 u16 _bfin_swrst;
 EXPORT_SYMBOL(_bfin_swrst);
@@ -1101,6 +1104,9 @@ void __init setup_arch(char **cmdline_p)
 #endif
 	init_exception_vectors();
 	bfin_cache_init();	/* Initialize caches for the boot CPU */
+#ifdef CONFIG_SCB_PRIORITY
+	init_scb();
+#endif
 }
 
 static int __init topology_init(void)