ath5k: Update gain_F calibration code and add documentation

 * Update and cleanup rf gain optimization code

 * Add comments and refferences to docs and use sane function names

 * Use only step index on ath5k_gain, no need to have a pointer to
   the current step since we can determine te step from it's index,
   this also allows us to put all other structs on rfgain.h and cleanup
   ath5k.h a little

 * No need for ah_rfgain variable, we use ah_gain.g_state for everything

 * Tested on RF2112B chip but gain_F calibration is not yet done
   (we will finish this on the next patch where we'll rewrite rf-buffer
   handling)

 * Use initial rf gain settings for 2316 and 2317 SoCs introduced on a previous patch

 It seems big but it's mostly cleanup, very few functional changes have been made on phy.c
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath5k/ath5k.h

@@ -649,49 +649,21 @@ struct ath5k_beacon_state {
 
 enum ath5k_rfgain {
 	AR5K_RFGAIN_INACTIVE = 0,
+	AR5K_RFGAIN_ACTIVE,
 	AR5K_RFGAIN_READ_REQUESTED,
 	AR5K_RFGAIN_NEED_CHANGE,
 };
 
-#define AR5K_GAIN_CRN_FIX_BITS_5111		4
-#define AR5K_GAIN_CRN_FIX_BITS_5112		7
-#define AR5K_GAIN_CRN_MAX_FIX_BITS		AR5K_GAIN_CRN_FIX_BITS_5112
-#define AR5K_GAIN_DYN_ADJUST_HI_MARGIN		15
-#define AR5K_GAIN_DYN_ADJUST_LO_MARGIN		20
-#define AR5K_GAIN_CCK_PROBE_CORR		5
-#define AR5K_GAIN_CCK_OFDM_GAIN_DELTA		15
-#define AR5K_GAIN_STEP_COUNT			10
-#define AR5K_GAIN_PARAM_TX_CLIP			0
-#define AR5K_GAIN_PARAM_PD_90			1
-#define AR5K_GAIN_PARAM_PD_84			2
-#define AR5K_GAIN_PARAM_GAIN_SEL		3
-#define AR5K_GAIN_PARAM_MIX_ORN			0
-#define AR5K_GAIN_PARAM_PD_138			1
-#define AR5K_GAIN_PARAM_PD_137			2
-#define AR5K_GAIN_PARAM_PD_136			3
-#define AR5K_GAIN_PARAM_PD_132			4
-#define AR5K_GAIN_PARAM_PD_131			5
-#define AR5K_GAIN_PARAM_PD_130			6
-#define AR5K_GAIN_CHECK_ADJUST(_g) 		\
-	((_g)->g_current <= (_g)->g_low || (_g)->g_current >= (_g)->g_high)
-
-struct ath5k_gain_opt_step {
-	s16				gos_param[AR5K_GAIN_CRN_MAX_FIX_BITS];
-	s32				gos_gain;
-};
-
 struct ath5k_gain {
-	u32			g_step_idx;
-	u32			g_current;
-	u32			g_target;
-	u32			g_low;
-	u32			g_high;
-	u32			g_f_corr;
-	u32			g_active;
-	const struct ath5k_gain_opt_step	*g_step;
+	u8			g_step_idx;
+	u8			g_current;
+	u8			g_target;
+	u8			g_low;
+	u8			g_high;
+	u8			g_f_corr;
+	u8			g_state;
 };
 
-
 /********************\
   COMMON DEFINITIONS
 \********************/
@@ -1053,7 +1025,6 @@ struct ath5k_hw {
 	bool			ah_running;
 	bool			ah_single_chip;
 	bool			ah_combined_mic;
-	enum ath5k_rfgain	ah_rf_gain;
 
 	u32			ah_mac_srev;
 	u16			ah_mac_version;
@@ -1262,9 +1233,9 @@ extern int ath5k_hw_write_initvals(struct ath5k_hw *ah, u8 mode, bool change_cha
 
 /* Initialize RF */
 extern int ath5k_hw_rfregs(struct ath5k_hw *ah, struct ieee80211_channel *channel, unsigned int mode);
-extern int ath5k_hw_rfgain(struct ath5k_hw *ah, unsigned int freq);
-extern enum ath5k_rfgain ath5k_hw_get_rf_gain(struct ath5k_hw *ah);
-extern int ath5k_hw_set_rfgain_opt(struct ath5k_hw *ah);
+extern int ath5k_hw_rfgain_init(struct ath5k_hw *ah, unsigned int freq);
+extern enum ath5k_rfgain ath5k_hw_gainf_calibrate(struct ath5k_hw *ah);
+extern int ath5k_hw_rfgain_opt_init(struct ath5k_hw *ah);
 /* PHY/RF channel functions */
 extern bool ath5k_channel_ok(struct ath5k_hw *ah, u16 freq, unsigned int flags);
 extern int ath5k_hw_channel(struct ath5k_hw *ah, struct ieee80211_channel *channel);

drivers/net/wireless/ath5k/attach.c

@@ -331,7 +331,7 @@ struct ath5k_hw *ath5k_hw_attach(struct ath5k_softc *sc, u8 mac_version)
 	ath5k_hw_set_associd(ah, ah->ah_bssid, 0);
 	ath5k_hw_set_opmode(ah);
 
-	ath5k_hw_set_rfgain_opt(ah);
+	ath5k_hw_rfgain_opt_init(ah);
 
 	return ah;
 err_free:

drivers/net/wireless/ath5k/base.c

@@ -2518,7 +2518,7 @@ ath5k_calibrate(unsigned long data)
 		ieee80211_frequency_to_channel(sc->curchan->center_freq),
 		sc->curchan->hw_value);
 
-	if (ath5k_hw_get_rf_gain(ah) == AR5K_RFGAIN_NEED_CHANGE) {
+	if (ath5k_hw_gainf_calibrate(ah) == AR5K_RFGAIN_NEED_CHANGE) {
 		/*
 		 * Rfgain is out of bounds, reset the chip
 		 * to load new gain values.

drivers/net/wireless/ath5k/reset.c

@@ -441,9 +441,6 @@ int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
 	s_led[1] = ath5k_hw_reg_read(ah, AR5K_GPIOCR);
 	s_led[2] = ath5k_hw_reg_read(ah, AR5K_GPIODO);
 
-	if (change_channel && ah->ah_rf_banks != NULL)
-		ath5k_hw_get_rf_gain(ah);
-
 
 	/*Wakeup the device*/
 	ret = ath5k_hw_nic_wakeup(ah, channel->hw_value, false);
@@ -530,7 +527,7 @@ int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
 		 * Write initial RF gain settings
 		 * This should work for both 5111/5112
 		 */
-		ret = ath5k_hw_rfgain(ah, freq);
+		ret = ath5k_hw_rfgain_init(ah, freq);
 		if (ret)
 			return ret;
 

drivers/net/wireless/ath5k/rfbuffer.h

@@ -111,6 +111,7 @@ enum ath5k_rf_regs_idx {
 #define	AR5K_RF5111_GAIN_I		{ 6, 29,  0 }
 #define	AR5K_RF5111_PLO_SEL		{ 1, 4,   0 }
 #define	AR5K_RF5111_RFGAIN_SEL		{ 1, 36,  0 }
+#define AR5K_RF5111_RFGAIN_STEP		{ 6, 37,  0 }
 /* Only on AR5212 BaseBand and up */
 #define	AR5K_RF5111_WAIT_S		{ 5, 19,  0 }
 #define	AR5K_RF5111_WAIT_I		{ 5, 24,  0 }
@@ -235,7 +236,9 @@ static const struct ath5k_ini_rfbuffer rfb_5111[] = {
 
 /* BANK 7 (Common)			len  pos col */
 #define	AR5K_RF5112X_GAIN_I		{ 6, 14,  0 }
+#define	AR5K_RF5112X_MIXVGA_OVR		{ 1, 36,  0 }
 #define	AR5K_RF5112X_MIXGAIN_OVR	{ 2, 37,  0 }
+#define AR5K_RF5112X_MIXGAIN_STEP	{ 4, 32,  0 }
 #define	AR5K_RF5112X_PD_DELAY_A		{ 4, 58,  0 }
 #define	AR5K_RF5112X_PD_DELAY_B		{ 4, 62,  0 }
 #define	AR5K_RF5112X_PD_DELAY_XR	{ 4, 66,  0 }

drivers/net/wireless/ath5k/rfgain.h

@@ -441,12 +441,38 @@ static const struct ath5k_ini_rfgain rfgain_2425[] = {
 	{ AR5K_RF_GAIN(63),	{ 0x00000000, 0x000000f9 } },
 };
 
+#define AR5K_GAIN_CRN_FIX_BITS_5111		4
+#define AR5K_GAIN_CRN_FIX_BITS_5112		7
+#define AR5K_GAIN_CRN_MAX_FIX_BITS		AR5K_GAIN_CRN_FIX_BITS_5112
+#define AR5K_GAIN_DYN_ADJUST_HI_MARGIN		15
+#define AR5K_GAIN_DYN_ADJUST_LO_MARGIN		20
+#define AR5K_GAIN_CCK_PROBE_CORR		5
+#define AR5K_GAIN_CCK_OFDM_GAIN_DELTA		15
+#define AR5K_GAIN_STEP_COUNT			10
+
+/* Check if our current measurement is inside our
+ * current variable attenuation window */
+#define AR5K_GAIN_CHECK_ADJUST(_g) 		\
+	((_g)->g_current <= (_g)->g_low || (_g)->g_current >= (_g)->g_high)
+
+struct ath5k_gain_opt_step {
+	s8				gos_param[AR5K_GAIN_CRN_MAX_FIX_BITS];
+	s8				gos_gain;
+};
+
 struct ath5k_gain_opt {
-	u32			go_default;
-	u32			go_steps_count;
+	u8				go_default;
+	u8				go_steps_count;
 	const struct ath5k_gain_opt_step	go_step[AR5K_GAIN_STEP_COUNT];
 };
 
+/*
+ * Parameters on gos_param:
+ * 1) Tx clip PHY register
+ * 2) PWD 90 RF register
+ * 3) PWD 84 RF register
+ * 4) RFGainSel RF register
+ */
 static const struct ath5k_gain_opt rfgain_opt_5111 = {
 	4,
 	9,
@@ -463,6 +489,16 @@ static const struct ath5k_gain_opt rfgain_opt_5111 = {
 	}
 };
 
+/*
+ * Parameters on gos_param:
+ * 1) Mixgain ovr RF register
+ * 2) PWD 138 RF register
+ * 3) PWD 137 RF register
+ * 4) PWD 136 RF register
+ * 5) PWD 132 RF register
+ * 6) PWD 131 RF register
+ * 7) PWD 130 RF register
+ */
 static const struct ath5k_gain_opt rfgain_opt_5112 = {
 	1,
 	8,