xref: /linux/drivers/net/wireless/mediatek/mt7601u/mac.c (revision 005438a8eef063495ac059d128eea71b58de50e5)
1 /*
2  * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
3  * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2
7  * as published by the Free Software Foundation
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include "mt7601u.h"
16 #include "trace.h"
17 #include <linux/etherdevice.h>
18 
19 static void
20 mt76_mac_process_tx_rate(struct ieee80211_tx_rate *txrate, u16 rate)
21 {
22 	u8 idx = MT76_GET(MT_TXWI_RATE_MCS, rate);
23 
24 	txrate->idx = 0;
25 	txrate->flags = 0;
26 	txrate->count = 1;
27 
28 	switch (MT76_GET(MT_TXWI_RATE_PHY_MODE, rate)) {
29 	case MT_PHY_TYPE_OFDM:
30 		txrate->idx = idx + 4;
31 		return;
32 	case MT_PHY_TYPE_CCK:
33 		if (idx >= 8)
34 			idx -= 8;
35 
36 		txrate->idx = idx;
37 		return;
38 	case MT_PHY_TYPE_HT_GF:
39 		txrate->flags |= IEEE80211_TX_RC_GREEN_FIELD;
40 		/* fall through */
41 	case MT_PHY_TYPE_HT:
42 		txrate->flags |= IEEE80211_TX_RC_MCS;
43 		txrate->idx = idx;
44 		break;
45 	default:
46 		WARN_ON(1);
47 		return;
48 	}
49 
50 	if (MT76_GET(MT_TXWI_RATE_BW, rate) == MT_PHY_BW_40)
51 		txrate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
52 
53 	if (rate & MT_TXWI_RATE_SGI)
54 		txrate->flags |= IEEE80211_TX_RC_SHORT_GI;
55 }
56 
57 static void
58 mt76_mac_fill_tx_status(struct mt7601u_dev *dev, struct ieee80211_tx_info *info,
59 			struct mt76_tx_status *st)
60 {
61 	struct ieee80211_tx_rate *rate = info->status.rates;
62 	int cur_idx, last_rate;
63 	int i;
64 
65 	last_rate = min_t(int, st->retry, IEEE80211_TX_MAX_RATES - 1);
66 	mt76_mac_process_tx_rate(&rate[last_rate], st->rate);
67 	if (last_rate < IEEE80211_TX_MAX_RATES - 1)
68 		rate[last_rate + 1].idx = -1;
69 
70 	cur_idx = rate[last_rate].idx + st->retry;
71 	for (i = 0; i <= last_rate; i++) {
72 		rate[i].flags = rate[last_rate].flags;
73 		rate[i].idx = max_t(int, 0, cur_idx - i);
74 		rate[i].count = 1;
75 	}
76 
77 	if (last_rate > 0)
78 		rate[last_rate - 1].count = st->retry + 1 - last_rate;
79 
80 	info->status.ampdu_len = 1;
81 	info->status.ampdu_ack_len = st->success;
82 
83 	if (st->is_probe)
84 		info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
85 
86 	if (st->aggr)
87 		info->flags |= IEEE80211_TX_CTL_AMPDU |
88 			       IEEE80211_TX_STAT_AMPDU;
89 
90 	if (!st->ack_req)
91 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
92 	else if (st->success)
93 		info->flags |= IEEE80211_TX_STAT_ACK;
94 }
95 
96 u16 mt76_mac_tx_rate_val(struct mt7601u_dev *dev,
97 			 const struct ieee80211_tx_rate *rate, u8 *nss_val)
98 {
99 	u16 rateval;
100 	u8 phy, rate_idx;
101 	u8 nss = 1;
102 	u8 bw = 0;
103 
104 	if (rate->flags & IEEE80211_TX_RC_MCS) {
105 		rate_idx = rate->idx;
106 		nss = 1 + (rate->idx >> 3);
107 		phy = MT_PHY_TYPE_HT;
108 		if (rate->flags & IEEE80211_TX_RC_GREEN_FIELD)
109 			phy = MT_PHY_TYPE_HT_GF;
110 		if (rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
111 			bw = 1;
112 	} else {
113 		const struct ieee80211_rate *r;
114 		int band = dev->chandef.chan->band;
115 		u16 val;
116 
117 		r = &dev->hw->wiphy->bands[band]->bitrates[rate->idx];
118 		if (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
119 			val = r->hw_value_short;
120 		else
121 			val = r->hw_value;
122 
123 		phy = val >> 8;
124 		rate_idx = val & 0xff;
125 		bw = 0;
126 	}
127 
128 	rateval = MT76_SET(MT_RXWI_RATE_MCS, rate_idx);
129 	rateval |= MT76_SET(MT_RXWI_RATE_PHY, phy);
130 	rateval |= MT76_SET(MT_RXWI_RATE_BW, bw);
131 	if (rate->flags & IEEE80211_TX_RC_SHORT_GI)
132 		rateval |= MT_RXWI_RATE_SGI;
133 
134 	*nss_val = nss;
135 	return rateval;
136 }
137 
138 void mt76_mac_wcid_set_rate(struct mt7601u_dev *dev, struct mt76_wcid *wcid,
139 			    const struct ieee80211_tx_rate *rate)
140 {
141 	unsigned long flags;
142 
143 	spin_lock_irqsave(&dev->lock, flags);
144 	wcid->tx_rate = mt76_mac_tx_rate_val(dev, rate, &wcid->tx_rate_nss);
145 	wcid->tx_rate_set = true;
146 	spin_unlock_irqrestore(&dev->lock, flags);
147 }
148 
149 struct mt76_tx_status mt7601u_mac_fetch_tx_status(struct mt7601u_dev *dev)
150 {
151 	struct mt76_tx_status stat = {};
152 	u32 val;
153 
154 	val = mt7601u_rr(dev, MT_TX_STAT_FIFO);
155 	stat.valid = !!(val & MT_TX_STAT_FIFO_VALID);
156 	stat.success = !!(val & MT_TX_STAT_FIFO_SUCCESS);
157 	stat.aggr = !!(val & MT_TX_STAT_FIFO_AGGR);
158 	stat.ack_req = !!(val & MT_TX_STAT_FIFO_ACKREQ);
159 	stat.pktid = MT76_GET(MT_TX_STAT_FIFO_PID_TYPE, val);
160 	stat.wcid = MT76_GET(MT_TX_STAT_FIFO_WCID, val);
161 	stat.rate = MT76_GET(MT_TX_STAT_FIFO_RATE, val);
162 
163 	return stat;
164 }
165 
166 void mt76_send_tx_status(struct mt7601u_dev *dev, struct mt76_tx_status *stat)
167 {
168 	struct ieee80211_tx_info info = {};
169 	struct ieee80211_sta *sta = NULL;
170 	struct mt76_wcid *wcid = NULL;
171 	void *msta;
172 
173 	rcu_read_lock();
174 	if (stat->wcid < ARRAY_SIZE(dev->wcid))
175 		wcid = rcu_dereference(dev->wcid[stat->wcid]);
176 
177 	if (wcid) {
178 		msta = container_of(wcid, struct mt76_sta, wcid);
179 		sta = container_of(msta, struct ieee80211_sta,
180 				   drv_priv);
181 	}
182 
183 	mt76_mac_fill_tx_status(dev, &info, stat);
184 	ieee80211_tx_status_noskb(dev->hw, sta, &info);
185 	rcu_read_unlock();
186 }
187 
188 void mt7601u_mac_set_protection(struct mt7601u_dev *dev, bool legacy_prot,
189 				int ht_mode)
190 {
191 	int mode = ht_mode & IEEE80211_HT_OP_MODE_PROTECTION;
192 	bool non_gf = !!(ht_mode & IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT);
193 	u32 prot[6];
194 	bool ht_rts[4] = {};
195 	int i;
196 
197 	prot[0] = MT_PROT_NAV_SHORT |
198 		  MT_PROT_TXOP_ALLOW_ALL |
199 		  MT_PROT_RTS_THR_EN;
200 	prot[1] = prot[0];
201 	if (legacy_prot)
202 		prot[1] |= MT_PROT_CTRL_CTS2SELF;
203 
204 	prot[2] = prot[4] = MT_PROT_NAV_SHORT | MT_PROT_TXOP_ALLOW_BW20;
205 	prot[3] = prot[5] = MT_PROT_NAV_SHORT | MT_PROT_TXOP_ALLOW_ALL;
206 
207 	if (legacy_prot) {
208 		prot[2] |= MT_PROT_RATE_CCK_11;
209 		prot[3] |= MT_PROT_RATE_CCK_11;
210 		prot[4] |= MT_PROT_RATE_CCK_11;
211 		prot[5] |= MT_PROT_RATE_CCK_11;
212 	} else {
213 		prot[2] |= MT_PROT_RATE_OFDM_24;
214 		prot[3] |= MT_PROT_RATE_DUP_OFDM_24;
215 		prot[4] |= MT_PROT_RATE_OFDM_24;
216 		prot[5] |= MT_PROT_RATE_DUP_OFDM_24;
217 	}
218 
219 	switch (mode) {
220 	case IEEE80211_HT_OP_MODE_PROTECTION_NONE:
221 		break;
222 
223 	case IEEE80211_HT_OP_MODE_PROTECTION_NONMEMBER:
224 		ht_rts[0] = ht_rts[1] = ht_rts[2] = ht_rts[3] = true;
225 		break;
226 
227 	case IEEE80211_HT_OP_MODE_PROTECTION_20MHZ:
228 		ht_rts[1] = ht_rts[3] = true;
229 		break;
230 
231 	case IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED:
232 		ht_rts[0] = ht_rts[1] = ht_rts[2] = ht_rts[3] = true;
233 		break;
234 	}
235 
236 	if (non_gf)
237 		ht_rts[2] = ht_rts[3] = true;
238 
239 	for (i = 0; i < 4; i++)
240 		if (ht_rts[i])
241 			prot[i + 2] |= MT_PROT_CTRL_RTS_CTS;
242 
243 	for (i = 0; i < 6; i++)
244 		mt7601u_wr(dev, MT_CCK_PROT_CFG + i * 4, prot[i]);
245 }
246 
247 void mt7601u_mac_set_short_preamble(struct mt7601u_dev *dev, bool short_preamb)
248 {
249 	if (short_preamb)
250 		mt76_set(dev, MT_AUTO_RSP_CFG, MT_AUTO_RSP_PREAMB_SHORT);
251 	else
252 		mt76_clear(dev, MT_AUTO_RSP_CFG, MT_AUTO_RSP_PREAMB_SHORT);
253 }
254 
255 void mt7601u_mac_config_tsf(struct mt7601u_dev *dev, bool enable, int interval)
256 {
257 	u32 val = mt7601u_rr(dev, MT_BEACON_TIME_CFG);
258 
259 	val &= ~(MT_BEACON_TIME_CFG_TIMER_EN |
260 		 MT_BEACON_TIME_CFG_SYNC_MODE |
261 		 MT_BEACON_TIME_CFG_TBTT_EN);
262 
263 	if (!enable) {
264 		mt7601u_wr(dev, MT_BEACON_TIME_CFG, val);
265 		return;
266 	}
267 
268 	val &= ~MT_BEACON_TIME_CFG_INTVAL;
269 	val |= MT76_SET(MT_BEACON_TIME_CFG_INTVAL, interval << 4) |
270 		MT_BEACON_TIME_CFG_TIMER_EN |
271 		MT_BEACON_TIME_CFG_SYNC_MODE |
272 		MT_BEACON_TIME_CFG_TBTT_EN;
273 }
274 
275 static void mt7601u_check_mac_err(struct mt7601u_dev *dev)
276 {
277 	u32 val = mt7601u_rr(dev, 0x10f4);
278 
279 	if (!(val & BIT(29)) || !(val & (BIT(7) | BIT(5))))
280 		return;
281 
282 	dev_err(dev->dev, "Error: MAC specific condition occurred\n");
283 
284 	mt76_set(dev, MT_MAC_SYS_CTRL, MT_MAC_SYS_CTRL_RESET_CSR);
285 	udelay(10);
286 	mt76_clear(dev, MT_MAC_SYS_CTRL, MT_MAC_SYS_CTRL_RESET_CSR);
287 }
288 
289 void mt7601u_mac_work(struct work_struct *work)
290 {
291 	struct mt7601u_dev *dev = container_of(work, struct mt7601u_dev,
292 					       mac_work.work);
293 	struct {
294 		u32 addr_base;
295 		u32 span;
296 		u64 *stat_base;
297 	} spans[] = {
298 		{ MT_RX_STA_CNT0,	3,	dev->stats.rx_stat },
299 		{ MT_TX_STA_CNT0,	3,	dev->stats.tx_stat },
300 		{ MT_TX_AGG_STAT,	1,	dev->stats.aggr_stat },
301 		{ MT_MPDU_DENSITY_CNT,	1,	dev->stats.zero_len_del },
302 		{ MT_TX_AGG_CNT_BASE0,	8,	&dev->stats.aggr_n[0] },
303 		{ MT_TX_AGG_CNT_BASE1,	8,	&dev->stats.aggr_n[16] },
304 	};
305 	u32 sum, n;
306 	int i, j, k;
307 
308 	/* Note: using MCU_RANDOM_READ is actually slower then reading all the
309 	 *	 registers by hand.  MCU takes ca. 20ms to complete read of 24
310 	 *	 registers while reading them one by one will takes roughly
311 	 *	 24*200us =~ 5ms.
312 	 */
313 
314 	k = 0;
315 	n = 0;
316 	sum = 0;
317 	for (i = 0; i < ARRAY_SIZE(spans); i++)
318 		for (j = 0; j < spans[i].span; j++) {
319 			u32 val = mt7601u_rr(dev, spans[i].addr_base + j * 4);
320 
321 			spans[i].stat_base[j * 2] += val & 0xffff;
322 			spans[i].stat_base[j * 2 + 1] += val >> 16;
323 
324 			/* Calculate average AMPDU length */
325 			if (spans[i].addr_base != MT_TX_AGG_CNT_BASE0 &&
326 			    spans[i].addr_base != MT_TX_AGG_CNT_BASE1)
327 				continue;
328 
329 			n += (val >> 16) + (val & 0xffff);
330 			sum += (val & 0xffff) * (1 + k * 2) +
331 				(val >> 16) * (2 + k * 2);
332 			k++;
333 		}
334 
335 	atomic_set(&dev->avg_ampdu_len, n ? DIV_ROUND_CLOSEST(sum, n) : 1);
336 
337 	mt7601u_check_mac_err(dev);
338 
339 	ieee80211_queue_delayed_work(dev->hw, &dev->mac_work, 10 * HZ);
340 }
341 
342 void
343 mt7601u_mac_wcid_setup(struct mt7601u_dev *dev, u8 idx, u8 vif_idx, u8 *mac)
344 {
345 	u8 zmac[ETH_ALEN] = {};
346 	u32 attr;
347 
348 	attr = MT76_SET(MT_WCID_ATTR_BSS_IDX, vif_idx & 7) |
349 	       MT76_SET(MT_WCID_ATTR_BSS_IDX_EXT, !!(vif_idx & 8));
350 
351 	mt76_wr(dev, MT_WCID_ATTR(idx), attr);
352 
353 	if (mac)
354 		memcpy(zmac, mac, sizeof(zmac));
355 
356 	mt7601u_addr_wr(dev, MT_WCID_ADDR(idx), zmac);
357 }
358 
359 void mt7601u_mac_set_ampdu_factor(struct mt7601u_dev *dev)
360 {
361 	struct ieee80211_sta *sta;
362 	struct mt76_wcid *wcid;
363 	void *msta;
364 	u8 min_factor = 3;
365 	int i;
366 
367 	rcu_read_lock();
368 	for (i = 0; i < ARRAY_SIZE(dev->wcid); i++) {
369 		wcid = rcu_dereference(dev->wcid[i]);
370 		if (!wcid)
371 			continue;
372 
373 		msta = container_of(wcid, struct mt76_sta, wcid);
374 		sta = container_of(msta, struct ieee80211_sta, drv_priv);
375 
376 		min_factor = min(min_factor, sta->ht_cap.ampdu_factor);
377 	}
378 	rcu_read_unlock();
379 
380 	mt7601u_wr(dev, MT_MAX_LEN_CFG, 0xa0fff |
381 		   MT76_SET(MT_MAX_LEN_CFG_AMPDU, min_factor));
382 }
383 
384 static void
385 mt76_mac_process_rate(struct ieee80211_rx_status *status, u16 rate)
386 {
387 	u8 idx = MT76_GET(MT_RXWI_RATE_MCS, rate);
388 
389 	switch (MT76_GET(MT_RXWI_RATE_PHY, rate)) {
390 	case MT_PHY_TYPE_OFDM:
391 		if (WARN_ON(idx >= 8))
392 			idx = 0;
393 		idx += 4;
394 
395 		status->rate_idx = idx;
396 		return;
397 	case MT_PHY_TYPE_CCK:
398 		if (idx >= 8) {
399 			idx -= 8;
400 			status->flag |= RX_FLAG_SHORTPRE;
401 		}
402 
403 		if (WARN_ON(idx >= 4))
404 			idx = 0;
405 
406 		status->rate_idx = idx;
407 		return;
408 	case MT_PHY_TYPE_HT_GF:
409 		status->flag |= RX_FLAG_HT_GF;
410 		/* fall through */
411 	case MT_PHY_TYPE_HT:
412 		status->flag |= RX_FLAG_HT;
413 		status->rate_idx = idx;
414 		break;
415 	default:
416 		WARN_ON(1);
417 		return;
418 	}
419 
420 	if (rate & MT_RXWI_RATE_SGI)
421 		status->flag |= RX_FLAG_SHORT_GI;
422 
423 	if (rate & MT_RXWI_RATE_STBC)
424 		status->flag |= 1 << RX_FLAG_STBC_SHIFT;
425 
426 	if (rate & MT_RXWI_RATE_BW)
427 		status->flag |= RX_FLAG_40MHZ;
428 }
429 
430 static void
431 mt7601u_rx_monitor_beacon(struct mt7601u_dev *dev, struct mt7601u_rxwi *rxwi,
432 			  u16 rate, int rssi)
433 {
434 	dev->bcn_freq_off = rxwi->freq_off;
435 	dev->bcn_phy_mode = MT76_GET(MT_RXWI_RATE_PHY, rate);
436 	dev->avg_rssi = (dev->avg_rssi * 15) / 16 + (rssi << 8);
437 }
438 
439 static int
440 mt7601u_rx_is_our_beacon(struct mt7601u_dev *dev, u8 *data)
441 {
442 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
443 
444 	return ieee80211_is_beacon(hdr->frame_control) &&
445 		ether_addr_equal(hdr->addr2, dev->ap_bssid);
446 }
447 
448 u32 mt76_mac_process_rx(struct mt7601u_dev *dev, struct sk_buff *skb,
449 			u8 *data, void *rxi)
450 {
451 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
452 	struct mt7601u_rxwi *rxwi = rxi;
453 	u32 len, ctl = le32_to_cpu(rxwi->ctl);
454 	u16 rate = le16_to_cpu(rxwi->rate);
455 	int rssi;
456 
457 	len = MT76_GET(MT_RXWI_CTL_MPDU_LEN, ctl);
458 	if (len < 10)
459 		return 0;
460 
461 	if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_DECRYPT)) {
462 		status->flag |= RX_FLAG_DECRYPTED;
463 		status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED;
464 	}
465 
466 	status->chains = BIT(0);
467 	rssi = mt7601u_phy_get_rssi(dev, rxwi, rate);
468 	status->chain_signal[0] = status->signal = rssi;
469 	status->freq = dev->chandef.chan->center_freq;
470 	status->band = dev->chandef.chan->band;
471 
472 	mt76_mac_process_rate(status, rate);
473 
474 	spin_lock_bh(&dev->con_mon_lock);
475 	if (mt7601u_rx_is_our_beacon(dev, data))
476 		mt7601u_rx_monitor_beacon(dev, rxwi, rate, rssi);
477 	else if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_U2M))
478 		dev->avg_rssi = (dev->avg_rssi * 15) / 16 + (rssi << 8);
479 	spin_unlock_bh(&dev->con_mon_lock);
480 
481 	return len;
482 }
483 
484 static enum mt76_cipher_type
485 mt76_mac_get_key_info(struct ieee80211_key_conf *key, u8 *key_data)
486 {
487 	memset(key_data, 0, 32);
488 	if (!key)
489 		return MT_CIPHER_NONE;
490 
491 	if (key->keylen > 32)
492 		return MT_CIPHER_NONE;
493 
494 	memcpy(key_data, key->key, key->keylen);
495 
496 	switch (key->cipher) {
497 	case WLAN_CIPHER_SUITE_WEP40:
498 		return MT_CIPHER_WEP40;
499 	case WLAN_CIPHER_SUITE_WEP104:
500 		return MT_CIPHER_WEP104;
501 	case WLAN_CIPHER_SUITE_TKIP:
502 		return MT_CIPHER_TKIP;
503 	case WLAN_CIPHER_SUITE_CCMP:
504 		return MT_CIPHER_AES_CCMP;
505 	default:
506 		return MT_CIPHER_NONE;
507 	}
508 }
509 
510 int mt76_mac_wcid_set_key(struct mt7601u_dev *dev, u8 idx,
511 			  struct ieee80211_key_conf *key)
512 {
513 	enum mt76_cipher_type cipher;
514 	u8 key_data[32];
515 	u8 iv_data[8];
516 	u32 val;
517 
518 	cipher = mt76_mac_get_key_info(key, key_data);
519 	if (cipher == MT_CIPHER_NONE && key)
520 		return -EINVAL;
521 
522 	trace_set_key(dev, idx);
523 
524 	mt7601u_wr_copy(dev, MT_WCID_KEY(idx), key_data, sizeof(key_data));
525 
526 	memset(iv_data, 0, sizeof(iv_data));
527 	if (key) {
528 		iv_data[3] = key->keyidx << 6;
529 		if (cipher >= MT_CIPHER_TKIP) {
530 			/* Note: start with 1 to comply with spec,
531 			 *	 (see comment on common/cmm_wpa.c:4291).
532 			 */
533 			iv_data[0] |= 1;
534 			iv_data[3] |= 0x20;
535 		}
536 	}
537 	mt7601u_wr_copy(dev, MT_WCID_IV(idx), iv_data, sizeof(iv_data));
538 
539 	val = mt7601u_rr(dev, MT_WCID_ATTR(idx));
540 	val &= ~MT_WCID_ATTR_PKEY_MODE & ~MT_WCID_ATTR_PKEY_MODE_EXT;
541 	val |= MT76_SET(MT_WCID_ATTR_PKEY_MODE, cipher & 7) |
542 	       MT76_SET(MT_WCID_ATTR_PKEY_MODE_EXT, cipher >> 3);
543 	val &= ~MT_WCID_ATTR_PAIRWISE;
544 	val |= MT_WCID_ATTR_PAIRWISE *
545 		!!(key && key->flags & IEEE80211_KEY_FLAG_PAIRWISE);
546 	mt7601u_wr(dev, MT_WCID_ATTR(idx), val);
547 
548 	return 0;
549 }
550 
551 int mt76_mac_shared_key_setup(struct mt7601u_dev *dev, u8 vif_idx, u8 key_idx,
552 			      struct ieee80211_key_conf *key)
553 {
554 	enum mt76_cipher_type cipher;
555 	u8 key_data[32];
556 	u32 val;
557 
558 	cipher = mt76_mac_get_key_info(key, key_data);
559 	if (cipher == MT_CIPHER_NONE && key)
560 		return -EINVAL;
561 
562 	trace_set_shared_key(dev, vif_idx, key_idx);
563 
564 	mt7601u_wr_copy(dev, MT_SKEY(vif_idx, key_idx),
565 			key_data, sizeof(key_data));
566 
567 	val = mt76_rr(dev, MT_SKEY_MODE(vif_idx));
568 	val &= ~(MT_SKEY_MODE_MASK << MT_SKEY_MODE_SHIFT(vif_idx, key_idx));
569 	val |= cipher << MT_SKEY_MODE_SHIFT(vif_idx, key_idx);
570 	mt76_wr(dev, MT_SKEY_MODE(vif_idx), val);
571 
572 	return 0;
573 }
574