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>

1 files changed, 53 insertions, 0 deletions

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]);
+	}
+
+}