[PATCH] Add v3020 RTC support

This patch adds support for the v3020 RTC from EM Microelectronic.

The v3020 RTC is designed to be connected on a bus using only one data bit.
 Since any data bit may be used, it is necessary to specify this to the
driver by passing a struct v3020_platform_data pointer (see
include/linux/rtc-v3020.h) to the driver.

Part of the following code comes from the kernel patchs produced by
Compulab for their products.  The original file (available here:
http://raph.people.8d.com/misc/emv3020.c) was released under the terms of
the GPL license.

[akpm@osdl.org: cleanups]
Signed-off-by: Raphael Assenat <raph@raphnet.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/rtc-v3020.h b/include/linux/rtc-v3020.h
new file mode 100644
index 0000000..bf74e63
--- /dev/null
+++ b/include/linux/rtc-v3020.h
@@ -0,0 +1,35 @@
+/*
+ * v3020.h - Registers definition and platform data structure for the v3020 RTC.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2006, 8D Technologies inc.
+ */
+#ifndef __LINUX_V3020_H
+#define __LINUX_V3020_H
+
+/* The v3020 has only one data pin but which one
+ * is used depends on the board. */
+struct v3020_platform_data {
+	int leftshift; /* (1<<(leftshift)) & readl() */
+};
+
+#define V3020_STATUS_0	0x00
+#define V3020_STATUS_1	0x01
+#define V3020_SECONDS	0x02
+#define V3020_MINUTES	0x03
+#define V3020_HOURS		0x04
+#define V3020_MONTH_DAY	0x05
+#define V3020_MONTH		0x06
+#define V3020_YEAR		0x07
+#define V3020_WEEK_DAY	0x08
+#define V3020_WEEK		0x09
+
+#define V3020_IS_COMMAND(val) ((val)>=0x0E)
+
+#define V3020_CMD_RAM2CLOCK	0x0E
+#define V3020_CMD_CLOCK2RAM	0x0F
+
+#endif /* __LINUX_V3020_H */