ARM: tty: Move HVC DCC assembly to arch/arm

Put architecture-specific assembly code where it belongs,
allowing for support of additional architectures such as arm64 in
the future.

Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/arch/arm/include/asm/dcc.h b/arch/arm/include/asm/dcc.h
new file mode 100644
index 000000000000..b74899de0774
--- /dev/null
+++ b/arch/arm/include/asm/dcc.h
@@ -0,0 +1,41 @@
+/* Copyright (c) 2010, 2014 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <asm/barrier.h>
+
+static inline u32 __dcc_getstatus(void)
+{
+	u32 __ret;
+	asm volatile("mrc p14, 0, %0, c0, c1, 0	@ read comms ctrl reg"
+		: "=r" (__ret) : : "cc");
+
+	return __ret;
+}
+
+static inline char __dcc_getchar(void)
+{
+	char __c;
+
+	asm volatile("mrc p14, 0, %0, c0, c5, 0	@ read comms data reg"
+		: "=r" (__c));
+	isb();
+
+	return __c;
+}
+
+static inline void __dcc_putchar(char c)
+{
+	asm volatile("mcr p14, 0, %0, c0, c5, 0	@ write a char"
+		: /* no output register */
+		: "r" (c));
+	isb();
+}