ARM: at91: add soc detection infrastructure

Add new structures and functions to handle AT91 SoC detection.

[alexandre.belloni@free-electrons.com: reworked DBGU detection]
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/arch/arm/mach-at91/soc.h b/arch/arm/mach-at91/soc.h
new file mode 100644
index 0000000..9678a3b
--- /dev/null
+++ b/arch/arm/mach-at91/soc.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2015 Atmel
+ *
+ * Boris Brezillon <boris.brezillon@free-electrons.com
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ */
+
+#ifndef __AT91_SOC_H
+#define __AT91_SOC_H
+
+#include <linux/sys_soc.h>
+
+struct at91_soc {
+	u32 cidr_match;
+	u32 exid_match;
+	const char *name;
+	const char *family;
+};
+
+#define AT91_SOC(__cidr, __exid, __name, __family)		\
+	{							\
+		.cidr_match = (__cidr),				\
+		.exid_match = (__exid),				\
+		.name = (__name),				\
+		.family = (__family),				\
+	}
+
+struct soc_device * __init
+at91_soc_init(const struct at91_soc *socs);
+
+#endif /* __AT91_SOC_H */