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authorFrederic Weisbecker2009-10-18 01:09:09 +0200
committerFrederic Weisbecker2009-10-18 01:12:33 +0200
commit0f8f86c7bdd1c954fbe153af437a0d91a6c5721a (patch)
tree94a8d419a470a4f9852ca397bb9bbe48db92ff5c /arch/mips/loongson/common/early_printk.c
parentMerge branch 'linus' into tracing/hw-breakpoints (diff)
parentperf tools: Move dereference after NULL test (diff)
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Merge commit 'perf/core' into perf/hw-breakpoint
Conflicts: kernel/Makefile kernel/trace/Makefile kernel/trace/trace.h samples/Makefile Merge reason: We need to be uptodate with the perf events development branch because we plan to rewrite the breakpoints API on top of perf events.
Diffstat (limited to 'arch/mips/loongson/common/early_printk.c')
-rw-r--r--arch/mips/loongson/common/early_printk.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/mips/loongson/common/early_printk.c b/arch/mips/loongson/common/early_printk.c
new file mode 100644
index 000000000000..bc73edc0cfd8
--- /dev/null
+++ b/arch/mips/loongson/common/early_printk.c
@@ -0,0 +1,38 @@
+/* early printk support
+ *
+ * Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
+ * Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology
+ * Author: Wu Zhangjin, wuzj@lemote.com
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#include <linux/serial_reg.h>
+
+#include <loongson.h>
+#include <machine.h>
+
+#define PORT(base, offset) (u8 *)(base + offset)
+
+static inline unsigned int serial_in(phys_addr_t base, int offset)
+{
+ return readb(PORT(base, offset));
+}
+
+static inline void serial_out(phys_addr_t base, int offset, int value)
+{
+ writeb(value, PORT(base, offset));
+}
+
+void prom_putchar(char c)
+{
+ phys_addr_t uart_base =
+ (phys_addr_t) ioremap_nocache(LOONGSON_UART_BASE, 8);
+
+ while ((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0)
+ ;
+
+ serial_out(uart_base, UART_TX, c);
+}