rt2x00: rt2800lib: introduce rt2800_eeprom_word_index helper

Instead of assign the offset value to the
enum directly use a new helper function to
convert a rt2800_eeprom_word enum into an
index of the rt2x00_dev->eeprom array.

The patch does not change the existing
behaviour, but makes it possible to add
support for three-chain devices which are
using a different EEPROM layout.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2800.h b/drivers/net/wireless/rt2x00/rt2800.h
index 0647039..bc5c695 100644
--- a/drivers/net/wireless/rt2x00/rt2800.h
+++ b/drivers/net/wireless/rt2x00/rt2800.h
@@ -2207,43 +2207,45 @@
  */
 
 enum rt2800_eeprom_word {
-	EEPROM_CHIP_ID		= 0x0000,
-	EEPROM_VERSION		= 0x0001,
-	EEPROM_MAC_ADDR_0	= 0x0002,
-	EEPROM_MAC_ADDR_1	= 0x0003,
-	EEPROM_MAC_ADDR_2	= 0x0004,
-	EEPROM_NIC_CONF0	= 0x001a,
-	EEPROM_NIC_CONF1	= 0x001b,
-	EEPROM_FREQ		= 0x001d,
-	EEPROM_LED_AG_CONF	= 0x001e,
-	EEPROM_LED_ACT_CONF	= 0x001f,
-	EEPROM_LED_POLARITY	= 0x0020,
-	EEPROM_NIC_CONF2	= 0x0021,
-	EEPROM_LNA		= 0x0022,
-	EEPROM_RSSI_BG		= 0x0023,
-	EEPROM_RSSI_BG2		= 0x0024,
-	EEPROM_TXMIXER_GAIN_BG	= 0x0024, /* overlaps with RSSI_BG2 */
-	EEPROM_RSSI_A		= 0x0025,
-	EEPROM_RSSI_A2		= 0x0026,
-	EEPROM_TXMIXER_GAIN_A	= 0x0026, /* overlaps with RSSI_A2 */
-	EEPROM_EIRP_MAX_TX_POWER = 0x0027,
-	EEPROM_TXPOWER_DELTA	= 0x0028,
-	EEPROM_TXPOWER_BG1	= 0x0029,
-	EEPROM_TXPOWER_BG2	= 0x0030,
-	EEPROM_TSSI_BOUND_BG1	= 0x0037,
-	EEPROM_TSSI_BOUND_BG2	= 0x0038,
-	EEPROM_TSSI_BOUND_BG3	= 0x0039,
-	EEPROM_TSSI_BOUND_BG4	= 0x003a,
-	EEPROM_TSSI_BOUND_BG5	= 0x003b,
-	EEPROM_TXPOWER_A1	= 0x003c,
-	EEPROM_TXPOWER_A2	= 0x0053,
-	EEPROM_TSSI_BOUND_A1	= 0x006a,
-	EEPROM_TSSI_BOUND_A2	= 0x006b,
-	EEPROM_TSSI_BOUND_A3	= 0x006c,
-	EEPROM_TSSI_BOUND_A4	= 0x006d,
-	EEPROM_TSSI_BOUND_A5	= 0x006e,
-	EEPROM_TXPOWER_BYRATE	= 0x006f,
-	EEPROM_BBP_START	= 0x0078,
+	EEPROM_CHIP_ID = 0,
+	EEPROM_VERSION,
+	EEPROM_MAC_ADDR_0,
+	EEPROM_MAC_ADDR_1,
+	EEPROM_MAC_ADDR_2,
+	EEPROM_NIC_CONF0,
+	EEPROM_NIC_CONF1,
+	EEPROM_FREQ,
+	EEPROM_LED_AG_CONF,
+	EEPROM_LED_ACT_CONF,
+	EEPROM_LED_POLARITY,
+	EEPROM_NIC_CONF2,
+	EEPROM_LNA,
+	EEPROM_RSSI_BG,
+	EEPROM_RSSI_BG2,
+	EEPROM_TXMIXER_GAIN_BG,
+	EEPROM_RSSI_A,
+	EEPROM_RSSI_A2,
+	EEPROM_TXMIXER_GAIN_A,
+	EEPROM_EIRP_MAX_TX_POWER,
+	EEPROM_TXPOWER_DELTA,
+	EEPROM_TXPOWER_BG1,
+	EEPROM_TXPOWER_BG2,
+	EEPROM_TSSI_BOUND_BG1,
+	EEPROM_TSSI_BOUND_BG2,
+	EEPROM_TSSI_BOUND_BG3,
+	EEPROM_TSSI_BOUND_BG4,
+	EEPROM_TSSI_BOUND_BG5,
+	EEPROM_TXPOWER_A1,
+	EEPROM_TXPOWER_A2,
+	EEPROM_TSSI_BOUND_A1,
+	EEPROM_TSSI_BOUND_A2,
+	EEPROM_TSSI_BOUND_A3,
+	EEPROM_TSSI_BOUND_A4,
+	EEPROM_TSSI_BOUND_A5,
+	EEPROM_TXPOWER_BYRATE,
+	EEPROM_BBP_START,
+	/* New values must be added before this */
+	EEPROM_WORD_COUNT
 };
 
 /*