ath5k: Check EEPROM before tweaking SERDES

* Read PCI-E infos offset from EEPROM and if it points to
   serdes section (0x40), enable serdes programming (further tweaking
   of serdes values during attach). This follows Legacy and Sam's
   HAL sources.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/attach.c

@@ -252,28 +252,6 @@ struct ath5k_hw *ath5k_hw_attach(struct ath5k_softc *sc, u8 mac_version)
 		goto err_free;
 	}
 
-	/*
-	 * Write PCI-E power save settings
-	 */
-	if ((ah->ah_version == AR5K_AR5212) && (pdev->is_pcie)) {
-		ath5k_hw_reg_write(ah, 0x9248fc00, AR5K_PCIE_SERDES);
-		ath5k_hw_reg_write(ah, 0x24924924, AR5K_PCIE_SERDES);
-		/* Shut off RX when elecidle is asserted */
-		ath5k_hw_reg_write(ah, 0x28000039, AR5K_PCIE_SERDES);
-		ath5k_hw_reg_write(ah, 0x53160824, AR5K_PCIE_SERDES);
-		/* TODO: EEPROM work */
-		ath5k_hw_reg_write(ah, 0xe5980579, AR5K_PCIE_SERDES);
-		/* Shut off PLL and CLKREQ active in L1 */
-		ath5k_hw_reg_write(ah, 0x001defff, AR5K_PCIE_SERDES);
-		/* Preserce other settings */
-		ath5k_hw_reg_write(ah, 0x1aaabe40, AR5K_PCIE_SERDES);
-		ath5k_hw_reg_write(ah, 0xbe105554, AR5K_PCIE_SERDES);
-		ath5k_hw_reg_write(ah, 0x000e3007, AR5K_PCIE_SERDES);
-		/* Reset SERDES to load new settings */
-		ath5k_hw_reg_write(ah, 0x00000000, AR5K_PCIE_SERDES_RESET);
-		mdelay(1);
-	}
-
 	/*
 	 * POST
 	 */
@@ -295,6 +273,40 @@ struct ath5k_hw *ath5k_hw_attach(struct ath5k_softc *sc, u8 mac_version)
 		goto err_free;
 	}
 
+	/*
+	 * Write PCI-E power save settings
+	 */
+	if ((ah->ah_version == AR5K_AR5212) && (pdev->is_pcie)) {
+		struct ath5k_eeprom_info *ee = &ah->ah_capabilities.cap_eeprom;
+
+		ath5k_hw_reg_write(ah, 0x9248fc00, AR5K_PCIE_SERDES);
+		ath5k_hw_reg_write(ah, 0x24924924, AR5K_PCIE_SERDES);
+
+		/* Shut off RX when elecidle is asserted */
+		ath5k_hw_reg_write(ah, 0x28000039, AR5K_PCIE_SERDES);
+		ath5k_hw_reg_write(ah, 0x53160824, AR5K_PCIE_SERDES);
+
+		/* If serdes programing is enabled, increase PCI-E
+		 * tx power for systems with long trace from host
+		 * to minicard connector. */
+		if (ee->ee_serdes)
+			ath5k_hw_reg_write(ah, 0xe5980579, AR5K_PCIE_SERDES);
+		else
+			ath5k_hw_reg_write(ah, 0xf6800579, AR5K_PCIE_SERDES);
+
+		/* Shut off PLL and CLKREQ active in L1 */
+		ath5k_hw_reg_write(ah, 0x001defff, AR5K_PCIE_SERDES);
+
+		/* Preserve other settings */
+		ath5k_hw_reg_write(ah, 0x1aaabe40, AR5K_PCIE_SERDES);
+		ath5k_hw_reg_write(ah, 0xbe105554, AR5K_PCIE_SERDES);
+		ath5k_hw_reg_write(ah, 0x000e3007, AR5K_PCIE_SERDES);
+
+		/* Reset SERDES to load new settings */
+		ath5k_hw_reg_write(ah, 0x00000000, AR5K_PCIE_SERDES_RESET);
+		mdelay(1);
+	}
+
 	/* Get misc capabilities */
 	ret = ath5k_hw_set_capabilities(ah);
 	if (ret) {

drivers/net/wireless/ath/ath5k/eeprom.c

@@ -167,6 +167,16 @@ ath5k_eeprom_init_header(struct ath5k_hw *ah)
 	ee->ee_rfkill_pin = (u8) AR5K_REG_MS(val, AR5K_EEPROM_RFKILL_GPIO_SEL);
 	ee->ee_rfkill_pol = val & AR5K_EEPROM_RFKILL_POLARITY ? true : false;
 
+	/* Check if PCIE_OFFSET points to PCIE_SERDES_SECTION
+	 * and enable serdes programming if needed.
+	 *
+	 * XXX: Serdes values seem to be fixed so
+	 * no need to read them here, we write them
+	 * during ath5k_hw_attach */
+	AR5K_EEPROM_READ(AR5K_EEPROM_PCIE_OFFSET, val);
+	ee->ee_serdes = (val == AR5K_EEPROM_PCIE_SERDES_SECTION) ?
+							true : false;
+
 	return 0;
 }
 

drivers/net/wireless/ath/ath5k/eeprom.h

@@ -19,6 +19,9 @@
 /*
  * Common ar5xxx EEPROM data offsets (set these on AR5K_EEPROM_BASE)
  */
+#define	AR5K_EEPROM_PCIE_OFFSET		0x02	/* Contains offset to PCI-E infos */
+#define	AR5K_EEPROM_PCIE_SERDES_SECTION	0x40	/* PCIE_OFFSET points here when
+						 * SERDES infos are present */
 #define AR5K_EEPROM_MAGIC		0x003d	/* EEPROM Magic number */
 #define AR5K_EEPROM_MAGIC_VALUE		0x5aa5	/* Default - found on EEPROM */
 #define AR5K_EEPROM_MAGIC_5212		0x0000145c /* 5212 */
@@ -391,6 +394,7 @@ struct ath5k_eeprom_info {
 	u8	ee_rfkill_pin;
 	bool	ee_rfkill_pol;
 	bool	ee_is_hb63;
+	bool	ee_serdes;
 	u16	ee_misc0;
 	u16	ee_misc1;
 	u16	ee_misc2;