1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Radio tuning for Maxim max2820 on RTL8180
4  *
5  * Copyright 2007 Andrea Merello <andrea.merello@gmail.com>
6  *
7  * Code from the BSD driver and the rtl8181 project have been
8  * very useful to understand certain things
9  *
10  * I want to thanks the Authors of such projects and the Ndiswrapper
11  * project Authors.
12  *
13  * A special Big Thanks also is for all people who donated me cards,
14  * making possible the creation of the original rtl8180 driver
15  * from which this code is derived!
16  */
17 
18 #include <linux/pci.h>
19 #include <linux/delay.h>
20 #include <net/mac80211.h>
21 
22 #include "rtl8180.h"
23 #include "max2820.h"
24 
25 static const u32 max2820_chan[] = {
26 	12, /* CH 1 */
27 	17,
28 	22,
29 	27,
30 	32,
31 	37,
32 	42,
33 	47,
34 	52,
35 	57,
36 	62,
37 	67,
38 	72,
39 	84, /* CH 14 */
40 };
41 
42 static void write_max2820(struct ieee80211_hw *dev, u8 addr, u32 data)
43 {
44 	struct rtl8180_priv *priv = dev->priv;
45 	u32 phy_config;
46 
47 	phy_config = 0x90 + (data & 0xf);
48 	phy_config <<= 16;
49 	phy_config += addr;
50 	phy_config <<= 8;
51 	phy_config += (data >> 4) & 0xff;
52 
53 	rtl818x_iowrite32(priv,
54 		(__le32 __iomem *) &priv->map->RFPinsOutput, phy_config);
55 
56 	msleep(1);
57 }
58 
59 static void max2820_write_phy_antenna(struct ieee80211_hw *dev, short chan)
60 {
61 	struct rtl8180_priv *priv = dev->priv;
62 	u8 ant;
63 
64 	ant = MAXIM_ANTENNA;
65 	if (priv->rfparam & RF_PARAM_ANTBDEFAULT)
66 		ant |= BB_ANTENNA_B;
67 	if (chan == 14)
68 		ant |= BB_ANTATTEN_CHAN14;
69 
70 	rtl8180_write_phy(dev, 0x10, ant);
71 }
72 
73 static u8 max2820_rf_calc_rssi(u8 agc, u8 sq)
74 {
75 	bool odd;
76 
77 	odd = !!(agc & 1);
78 
79 	agc >>= 1;
80 	if (odd)
81 		agc += 76;
82 	else
83 		agc += 66;
84 
85 	/* TODO: change addends above to avoid mult / div below */
86 	return 65 * agc / 100;
87 }
88 
89 static void max2820_rf_set_channel(struct ieee80211_hw *dev,
90 				   struct ieee80211_conf *conf)
91 {
92 	struct rtl8180_priv *priv = dev->priv;
93 	int channel = conf ?
94 		ieee80211_frequency_to_channel(conf->chandef.chan->center_freq) : 1;
95 	unsigned int chan_idx = channel - 1;
96 	u32 txpw = priv->channels[chan_idx].hw_value & 0xFF;
97 	u32 chan = max2820_chan[chan_idx];
98 
99 	/* While philips SA2400 drive the PA bias from
100 	 * sa2400, for MAXIM we do this directly from BB */
101 	rtl8180_write_phy(dev, 3, txpw);
102 
103 	max2820_write_phy_antenna(dev, channel);
104 	write_max2820(dev, 3, chan);
105 }
106 
107 static void max2820_rf_stop(struct ieee80211_hw *dev)
108 {
109 	rtl8180_write_phy(dev, 3, 0x8);
110 	write_max2820(dev, 1, 0);
111 }
112 
113 
114 static void max2820_rf_init(struct ieee80211_hw *dev)
115 {
116 	struct rtl8180_priv *priv = dev->priv;
117 
118 	/* MAXIM from netbsd driver */
119 	write_max2820(dev, 0, 0x007); /* test mode as indicated in datasheet */
120 	write_max2820(dev, 1, 0x01e); /* enable register */
121 	write_max2820(dev, 2, 0x001); /* synt register */
122 
123 	max2820_rf_set_channel(dev, NULL);
124 
125 	write_max2820(dev, 4, 0x313); /* rx register */
126 
127 	/* PA is driven directly by the BB, we keep the MAXIM bias
128 	 * at the highest value in case that setting it to lower
129 	 * values may introduce some further attenuation somewhere..
130 	 */
131 	write_max2820(dev, 5, 0x00f);
132 
133 	/* baseband configuration */
134 	rtl8180_write_phy(dev, 0, 0x88); /* sys1       */
135 	rtl8180_write_phy(dev, 3, 0x08); /* txagc      */
136 	rtl8180_write_phy(dev, 4, 0xf8); /* lnadet     */
137 	rtl8180_write_phy(dev, 5, 0x90); /* ifagcinit  */
138 	rtl8180_write_phy(dev, 6, 0x1a); /* ifagclimit */
139 	rtl8180_write_phy(dev, 7, 0x64); /* ifagcdet   */
140 
141 	max2820_write_phy_antenna(dev, 1);
142 
143 	rtl8180_write_phy(dev, 0x11, 0x88); /* trl */
144 
145 	if (rtl818x_ioread8(priv, &priv->map->CONFIG2) &
146 	    RTL818X_CONFIG2_ANTENNA_DIV)
147 		rtl8180_write_phy(dev, 0x12, 0xc7);
148 	else
149 		rtl8180_write_phy(dev, 0x12, 0x47);
150 
151 	rtl8180_write_phy(dev, 0x13, 0x9b);
152 
153 	rtl8180_write_phy(dev, 0x19, 0x0);  /* CHESTLIM */
154 	rtl8180_write_phy(dev, 0x1a, 0x9f); /* CHSQLIM  */
155 
156 	max2820_rf_set_channel(dev, NULL);
157 }
158 
159 const struct rtl818x_rf_ops max2820_rf_ops = {
160 	.name		= "Maxim",
161 	.init		= max2820_rf_init,
162 	.stop		= max2820_rf_stop,
163 	.set_chan	= max2820_rf_set_channel,
164 	.calc_rssi	= max2820_rf_calc_rssi,
165 };
166