misc/eeprom: add driver for microwire 93xx46 EEPROMs

Add EEPROM driver for 93xx46 chips.  It can also be used with spi_gpio
driver to access 93xx46 EEPROMs connected over GPIO lines.  This driver
supports read/write/erase access to the EEPROM chips over sysfs files.

[rdunlap@xenotime.net: fix printk format]
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/eeprom_93xx46.h b/include/linux/eeprom_93xx46.h
new file mode 100644
index 0000000..0679181
--- /dev/null
+++ b/include/linux/eeprom_93xx46.h
@@ -0,0 +1,18 @@
+/*
+ * Module: eeprom_93xx46
+ * platform description for 93xx46 EEPROMs.
+ */
+
+struct eeprom_93xx46_platform_data {
+	unsigned char	flags;
+#define EE_ADDR8	0x01		/*  8 bit addr. cfg */
+#define EE_ADDR16	0x02		/* 16 bit addr. cfg */
+#define EE_READONLY	0x08		/* forbid writing */
+
+	/*
+	 * optional hooks to control additional logic
+	 * before and after spi transfer.
+	 */
+	void (*prepare)(void *);
+	void (*finish)(void *);
+};