xref: /openbmc/linux/drivers/net/wireless/mediatek/mt76/eeprom.c (revision 7d424a990e050ac09a0646edca083dcb4a516855)
1 // SPDX-License-Identifier: ISC
2 /*
3  * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
4  */
5 #include <linux/of.h>
6 #include <linux/of_net.h>
7 #include <linux/mtd/mtd.h>
8 #include <linux/mtd/partitions.h>
9 #include <linux/etherdevice.h>
10 #include "mt76.h"
11 
12 static int mt76_get_of_eeprom_data(struct mt76_dev *dev, void *eep, int len)
13 {
14 	struct device_node *np = dev->dev->of_node;
15 	const void *data;
16 	int size;
17 
18 	data = of_get_property(np, "mediatek,eeprom-data", &size);
19 	if (!data)
20 		return -ENOENT;
21 
22 	if (size > len)
23 		return -EINVAL;
24 
25 	memcpy(eep, data, size);
26 
27 	return 0;
28 }
29 
30 static int mt76_get_of_epprom_from_mtd(struct mt76_dev *dev, void *eep, int offset, int len)
31 {
32 #ifdef CONFIG_MTD
33 	struct device_node *np = dev->dev->of_node;
34 	struct mtd_info *mtd;
35 	const __be32 *list;
36 	const char *part;
37 	phandle phandle;
38 	size_t retlen;
39 	int size;
40 	int ret;
41 
42 	list = of_get_property(np, "mediatek,mtd-eeprom", &size);
43 	if (!list)
44 		return -ENOENT;
45 
46 	phandle = be32_to_cpup(list++);
47 	if (!phandle)
48 		return -ENOENT;
49 
50 	np = of_find_node_by_phandle(phandle);
51 	if (!np)
52 		return -EINVAL;
53 
54 	part = of_get_property(np, "label", NULL);
55 	if (!part)
56 		part = np->name;
57 
58 	mtd = get_mtd_device_nm(part);
59 	if (IS_ERR(mtd)) {
60 		ret =  PTR_ERR(mtd);
61 		goto out_put_node;
62 	}
63 
64 	if (size <= sizeof(*list)) {
65 		ret = -EINVAL;
66 		goto out_put_node;
67 	}
68 
69 	offset = be32_to_cpup(list);
70 	ret = mtd_read(mtd, offset, len, &retlen, eep);
71 	put_mtd_device(mtd);
72 	if (mtd_is_bitflip(ret))
73 		ret = 0;
74 	if (ret) {
75 		dev_err(dev->dev, "reading EEPROM from mtd %s failed: %i\n",
76 			part, ret);
77 		goto out_put_node;
78 	}
79 
80 	if (retlen < len) {
81 		ret = -EINVAL;
82 		goto out_put_node;
83 	}
84 
85 	if (of_property_read_bool(dev->dev->of_node, "big-endian")) {
86 		u8 *data = (u8 *)eep;
87 		int i;
88 
89 		/* convert eeprom data in Little Endian */
90 		for (i = 0; i < round_down(len, 2); i += 2)
91 			put_unaligned_le16(get_unaligned_be16(&data[i]),
92 					   &data[i]);
93 	}
94 
95 #ifdef CONFIG_NL80211_TESTMODE
96 	dev->test_mtd.name = devm_kstrdup(dev->dev, part, GFP_KERNEL);
97 	dev->test_mtd.offset = offset;
98 #endif
99 
100 out_put_node:
101 	of_node_put(np);
102 	return ret;
103 #else
104 	return -ENOENT;
105 #endif
106 }
107 
108 int mt76_get_of_eeprom(struct mt76_dev *dev, void *eep, int offset, int len)
109 {
110 	struct device_node *np = dev->dev->of_node;
111 	int ret;
112 
113 	if (!np)
114 		return -ENOENT;
115 
116 	ret = mt76_get_of_eeprom_data(dev, eep, len);
117 	if (!ret)
118 		return 0;
119 
120 	return mt76_get_of_epprom_from_mtd(dev, eep, offset, len);
121 }
122 EXPORT_SYMBOL_GPL(mt76_get_of_eeprom);
123 
124 void
125 mt76_eeprom_override(struct mt76_phy *phy)
126 {
127 	struct mt76_dev *dev = phy->dev;
128 	struct device_node *np = dev->dev->of_node;
129 
130 	of_get_mac_address(np, phy->macaddr);
131 
132 	if (!is_valid_ether_addr(phy->macaddr)) {
133 		eth_random_addr(phy->macaddr);
134 		dev_info(dev->dev,
135 			 "Invalid MAC address, using random address %pM\n",
136 			 phy->macaddr);
137 	}
138 }
139 EXPORT_SYMBOL_GPL(mt76_eeprom_override);
140 
141 static bool mt76_string_prop_find(struct property *prop, const char *str)
142 {
143 	const char *cp = NULL;
144 
145 	if (!prop || !str || !str[0])
146 		return false;
147 
148 	while ((cp = of_prop_next_string(prop, cp)) != NULL)
149 		if (!strcasecmp(cp, str))
150 			return true;
151 
152 	return false;
153 }
154 
155 static struct device_node *
156 mt76_find_power_limits_node(struct mt76_dev *dev)
157 {
158 	struct device_node *np = dev->dev->of_node;
159 	const char *const region_names[] = {
160 		[NL80211_DFS_UNSET] = "ww",
161 		[NL80211_DFS_ETSI] = "etsi",
162 		[NL80211_DFS_FCC] = "fcc",
163 		[NL80211_DFS_JP] = "jp",
164 	};
165 	struct device_node *cur, *fallback = NULL;
166 	const char *region_name = NULL;
167 
168 	if (dev->region < ARRAY_SIZE(region_names))
169 		region_name = region_names[dev->region];
170 
171 	np = of_get_child_by_name(np, "power-limits");
172 	if (!np)
173 		return NULL;
174 
175 	for_each_child_of_node(np, cur) {
176 		struct property *country = of_find_property(cur, "country", NULL);
177 		struct property *regd = of_find_property(cur, "regdomain", NULL);
178 
179 		if (!country && !regd) {
180 			fallback = cur;
181 			continue;
182 		}
183 
184 		if (mt76_string_prop_find(country, dev->alpha2) ||
185 		    mt76_string_prop_find(regd, region_name)) {
186 			of_node_put(np);
187 			return cur;
188 		}
189 	}
190 
191 	of_node_put(np);
192 	return fallback;
193 }
194 
195 static const __be32 *
196 mt76_get_of_array(struct device_node *np, char *name, size_t *len, int min)
197 {
198 	struct property *prop = of_find_property(np, name, NULL);
199 
200 	if (!prop || !prop->value || prop->length < min * 4)
201 		return NULL;
202 
203 	*len = prop->length;
204 
205 	return prop->value;
206 }
207 
208 static struct device_node *
209 mt76_find_channel_node(struct device_node *np, struct ieee80211_channel *chan)
210 {
211 	struct device_node *cur;
212 	const __be32 *val;
213 	size_t len;
214 
215 	for_each_child_of_node(np, cur) {
216 		val = mt76_get_of_array(cur, "channels", &len, 2);
217 		if (!val)
218 			continue;
219 
220 		while (len >= 2 * sizeof(*val)) {
221 			if (chan->hw_value >= be32_to_cpu(val[0]) &&
222 			    chan->hw_value <= be32_to_cpu(val[1]))
223 				return cur;
224 
225 			val += 2;
226 			len -= 2 * sizeof(*val);
227 		}
228 	}
229 
230 	return NULL;
231 }
232 
233 static s8
234 mt76_get_txs_delta(struct device_node *np, u8 nss)
235 {
236 	const __be32 *val;
237 	size_t len;
238 
239 	val = mt76_get_of_array(np, "txs-delta", &len, nss);
240 	if (!val)
241 		return 0;
242 
243 	return be32_to_cpu(val[nss - 1]);
244 }
245 
246 static void
247 mt76_apply_array_limit(s8 *pwr, size_t pwr_len, const __be32 *data,
248 		       s8 target_power, s8 nss_delta, s8 *max_power)
249 {
250 	int i;
251 
252 	if (!data)
253 		return;
254 
255 	for (i = 0; i < pwr_len; i++) {
256 		pwr[i] = min_t(s8, target_power,
257 			       be32_to_cpu(data[i]) + nss_delta);
258 		*max_power = max(*max_power, pwr[i]);
259 	}
260 }
261 
262 static void
263 mt76_apply_multi_array_limit(s8 *pwr, size_t pwr_len, s8 pwr_num,
264 			     const __be32 *data, size_t len, s8 target_power,
265 			     s8 nss_delta, s8 *max_power)
266 {
267 	int i, cur;
268 
269 	if (!data)
270 		return;
271 
272 	len /= 4;
273 	cur = be32_to_cpu(data[0]);
274 	for (i = 0; i < pwr_num; i++) {
275 		if (len < pwr_len + 1)
276 			break;
277 
278 		mt76_apply_array_limit(pwr + pwr_len * i, pwr_len, data + 1,
279 				       target_power, nss_delta, max_power);
280 		if (--cur > 0)
281 			continue;
282 
283 		data += pwr_len + 1;
284 		len -= pwr_len + 1;
285 		if (!len)
286 			break;
287 
288 		cur = be32_to_cpu(data[0]);
289 	}
290 }
291 
292 s8 mt76_get_rate_power_limits(struct mt76_phy *phy,
293 			      struct ieee80211_channel *chan,
294 			      struct mt76_power_limits *dest,
295 			      s8 target_power)
296 {
297 	struct mt76_dev *dev = phy->dev;
298 	struct device_node *np;
299 	const __be32 *val;
300 	char name[16];
301 	u32 mcs_rates = dev->drv->mcs_rates;
302 	u32 ru_rates = ARRAY_SIZE(dest->ru[0]);
303 	char band;
304 	size_t len;
305 	s8 max_power = 0;
306 	s8 txs_delta;
307 
308 	if (!mcs_rates)
309 		mcs_rates = 10;
310 
311 	memset(dest, target_power, sizeof(*dest));
312 
313 	if (!IS_ENABLED(CONFIG_OF))
314 		return target_power;
315 
316 	np = mt76_find_power_limits_node(dev);
317 	if (!np)
318 		return target_power;
319 
320 	switch (chan->band) {
321 	case NL80211_BAND_2GHZ:
322 		band = '2';
323 		break;
324 	case NL80211_BAND_5GHZ:
325 		band = '5';
326 		break;
327 	case NL80211_BAND_6GHZ:
328 		band = '6';
329 		break;
330 	default:
331 		return target_power;
332 	}
333 
334 	snprintf(name, sizeof(name), "txpower-%cg", band);
335 	np = of_get_child_by_name(np, name);
336 	if (!np)
337 		return target_power;
338 
339 	np = mt76_find_channel_node(np, chan);
340 	if (!np)
341 		return target_power;
342 
343 	txs_delta = mt76_get_txs_delta(np, hweight8(phy->antenna_mask));
344 
345 	val = mt76_get_of_array(np, "rates-cck", &len, ARRAY_SIZE(dest->cck));
346 	mt76_apply_array_limit(dest->cck, ARRAY_SIZE(dest->cck), val,
347 			       target_power, txs_delta, &max_power);
348 
349 	val = mt76_get_of_array(np, "rates-ofdm",
350 				&len, ARRAY_SIZE(dest->ofdm));
351 	mt76_apply_array_limit(dest->ofdm, ARRAY_SIZE(dest->ofdm), val,
352 			       target_power, txs_delta, &max_power);
353 
354 	val = mt76_get_of_array(np, "rates-mcs", &len, mcs_rates + 1);
355 	mt76_apply_multi_array_limit(dest->mcs[0], ARRAY_SIZE(dest->mcs[0]),
356 				     ARRAY_SIZE(dest->mcs), val, len,
357 				     target_power, txs_delta, &max_power);
358 
359 	val = mt76_get_of_array(np, "rates-ru", &len, ru_rates + 1);
360 	mt76_apply_multi_array_limit(dest->ru[0], ARRAY_SIZE(dest->ru[0]),
361 				     ARRAY_SIZE(dest->ru), val, len,
362 				     target_power, txs_delta, &max_power);
363 
364 	return max_power;
365 }
366 EXPORT_SYMBOL_GPL(mt76_get_rate_power_limits);
367 
368 int
369 mt76_eeprom_init(struct mt76_dev *dev, int len)
370 {
371 	dev->eeprom.size = len;
372 	dev->eeprom.data = devm_kzalloc(dev->dev, len, GFP_KERNEL);
373 	if (!dev->eeprom.data)
374 		return -ENOMEM;
375 
376 	return !mt76_get_of_eeprom(dev, dev->eeprom.data, 0, len);
377 }
378 EXPORT_SYMBOL_GPL(mt76_eeprom_init);
379