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>

2 files changed, 54 insertions, 0 deletions

diff --git a/arch/blackfin/mach-common/Makefile b/arch/blackfin/mach-common/Makefile
index 675466d490d4..f09979204040 100644
--- a/arch/blackfin/mach-common/Makefile
+++ b/arch/blackfin/mach-common/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_PM)          += pm.o
 ifneq ($(CONFIG_BF60x),y)
 obj-$(CONFIG_PM)          += dpmc_modes.o
 endif
+obj-$(CONFIG_SCB_PRIORITY)      += scb-init.o
 obj-$(CONFIG_CPU_VOLTAGE) += dpmc.o
 obj-$(CONFIG_SMP)         += smp.o
 obj-$(CONFIG_BFIN_KERNEL_CLOCK) += clocks-init.o
diff --git a/arch/blackfin/mach-common/scb-init.c b/arch/blackfin/mach-common/scb-init.c
new file mode 100644
index 000000000000..2cbfb0b5679e
--- /dev/null
+++ b/arch/blackfin/mach-common/scb-init.c
@@ -0,0 +1,53 @@
+/*
+ * arch/blackfin/mach-common/scb-init.c - reprogram system cross bar priority
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <asm/scb.h>
+
+__attribute__((l1_text))
+inline void scb_mi_write(unsigned long scb_mi_arbw, unsigned int slots,
+                unsigned char *scb_mi_prio)
+{
+        unsigned int i;
+
+        for (i = 0; i < slots; ++i)
+                bfin_write32(scb_mi_arbw, (i << SCB_SLOT_OFFSET) | scb_mi_prio[i]);
+}
+
+__attribute__((l1_text))
+inline void scb_mi_read(unsigned long scb_mi_arbw, unsigned int slots,
+                unsigned char *scb_mi_prio)
+{
+        unsigned int i;
+
+        for (i = 0; i < slots; ++i) {
+                bfin_write32(scb_mi_arbw, (0xFF << SCB_SLOT_OFFSET) | i);
+                scb_mi_prio[i] = bfin_read32(scb_mi_arbw);
+        }
+}
+
+__attribute__((l1_text))
+void init_scb(void)
+{
+        unsigned int i, j;
+        unsigned char scb_tmp_prio[32];
+
+        pr_info("Init System Crossbar\n");
+        for (i = 0; scb_data[i].scb_mi_arbr > 0; ++i) {
+
+                scb_mi_write(scb_data[i].scb_mi_arbw, scb_data[i].scb_mi_slots, scb_data[i].scb_mi_prio);
+
+                pr_debug("scb priority at 0x%lx:\n", scb_data[i].scb_mi_arbr);
+                scb_mi_read(scb_data[i].scb_mi_arbw, scb_data[i].scb_mi_slots, scb_tmp_prio);
+                for (j = 0; j < scb_data[i].scb_mi_slots; ++j)
+                        pr_debug("slot %d = %d\n", j, scb_tmp_prio[j]);
+        }
+
+}