eeprom_93cx6: Add write support

Add support for writing data to EEPROM.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/eeprom_93cx6.h b/include/linux/eeprom_93cx6.h
index e04546e..e50f98b 100644
--- a/include/linux/eeprom_93cx6.h
+++ b/include/linux/eeprom_93cx6.h
@@ -33,6 +33,7 @@
 #define PCI_EEPROM_WIDTH_93C86	8
 #define PCI_EEPROM_WIDTH_OPCODE	3
 #define PCI_EEPROM_WRITE_OPCODE	0x05
+#define PCI_EEPROM_ERASE_OPCODE 0x07
 #define PCI_EEPROM_READ_OPCODE	0x06
 #define PCI_EEPROM_EWDS_OPCODE	0x10
 #define PCI_EEPROM_EWEN_OPCODE	0x13
@@ -74,3 +75,8 @@
 	const u8 word, u16 *data);
 extern void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom,
 	const u8 word, __le16 *data, const u16 words);
+
+extern void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable);
+
+extern void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom,
+			       u8 addr, u16 data);