xref: /linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/btcoex.c (revision 95298d63c67673c654c08952672d016212b26054)
1 // SPDX-License-Identifier: ISC
2 /*
3  * Copyright (c) 2013 Broadcom Corporation
4  */
5 #include <linux/slab.h>
6 #include <linux/netdevice.h>
7 #include <net/cfg80211.h>
8 
9 #include <brcmu_wifi.h>
10 #include <brcmu_utils.h>
11 #include <defs.h>
12 #include "core.h"
13 #include "debug.h"
14 #include "fwil.h"
15 #include "fwil_types.h"
16 #include "btcoex.h"
17 #include "p2p.h"
18 #include "cfg80211.h"
19 
20 /* T1 start SCO/eSCO priority suppression */
21 #define BRCMF_BTCOEX_OPPR_WIN_TIME   msecs_to_jiffies(2000)
22 
23 /* BT registers values during DHCP */
24 #define BRCMF_BT_DHCP_REG50 0x8022
25 #define BRCMF_BT_DHCP_REG51 0
26 #define BRCMF_BT_DHCP_REG64 0
27 #define BRCMF_BT_DHCP_REG65 0
28 #define BRCMF_BT_DHCP_REG71 0
29 #define BRCMF_BT_DHCP_REG66 0x2710
30 #define BRCMF_BT_DHCP_REG41 0x33
31 #define BRCMF_BT_DHCP_REG68 0x190
32 
33 /* number of samples for SCO detection */
34 #define BRCMF_BT_SCO_SAMPLES 12
35 
36 /**
37 * enum brcmf_btcoex_state - BT coex DHCP state machine states
38 * @BRCMF_BT_DHCP_IDLE: DCHP is idle
39 * @BRCMF_BT_DHCP_START: DHCP started, wait before
40 *	boosting wifi priority
41 * @BRCMF_BT_DHCP_OPPR_WIN: graceful DHCP opportunity ended,
42 *	boost wifi priority
43 * @BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT: wifi priority boost end,
44 *	restore defaults
45 */
46 enum brcmf_btcoex_state {
47 	BRCMF_BT_DHCP_IDLE,
48 	BRCMF_BT_DHCP_START,
49 	BRCMF_BT_DHCP_OPPR_WIN,
50 	BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT
51 };
52 
53 /**
54  * struct brcmf_btcoex_info - BT coex related information
55  * @vif: interface for which request was done.
56  * @timer: timer for DHCP state machine
57  * @timeout: configured timeout.
58  * @timer_on:  DHCP timer active
59  * @dhcp_done: DHCP finished before T1/T2 timer expiration
60  * @bt_state: DHCP state machine state
61  * @work: DHCP state machine work
62  * @cfg: driver private data for cfg80211 interface
63  * @reg66: saved value of btc_params 66
64  * @reg41: saved value of btc_params 41
65  * @reg68: saved value of btc_params 68
66  * @saved_regs_part1: flag indicating regs 66,41,68
67  *	have been saved
68  * @reg51: saved value of btc_params 51
69  * @reg64: saved value of btc_params 64
70  * @reg65: saved value of btc_params 65
71  * @reg71: saved value of btc_params 71
72  * @saved_regs_part1: flag indicating regs 50,51,64,65,71
73  *	have been saved
74  */
75 struct brcmf_btcoex_info {
76 	struct brcmf_cfg80211_vif *vif;
77 	struct timer_list timer;
78 	u16 timeout;
79 	bool timer_on;
80 	bool dhcp_done;
81 	enum brcmf_btcoex_state bt_state;
82 	struct work_struct work;
83 	struct brcmf_cfg80211_info *cfg;
84 	u32 reg66;
85 	u32 reg41;
86 	u32 reg68;
87 	bool saved_regs_part1;
88 	u32 reg50;
89 	u32 reg51;
90 	u32 reg64;
91 	u32 reg65;
92 	u32 reg71;
93 	bool saved_regs_part2;
94 };
95 
96 /**
97  * brcmf_btcoex_params_write() - write btc_params firmware variable
98  * @ifp: interface
99  * @addr: btc_params register number
100  * @data: data to write
101  */
102 static s32 brcmf_btcoex_params_write(struct brcmf_if *ifp, u32 addr, u32 data)
103 {
104 	struct {
105 		__le32 addr;
106 		__le32 data;
107 	} reg_write;
108 
109 	reg_write.addr = cpu_to_le32(addr);
110 	reg_write.data = cpu_to_le32(data);
111 	return brcmf_fil_iovar_data_set(ifp, "btc_params",
112 					&reg_write, sizeof(reg_write));
113 }
114 
115 /**
116  * brcmf_btcoex_params_read() - read btc_params firmware variable
117  * @ifp: interface
118  * @addr: btc_params register number
119  * @data: read data
120  */
121 static s32 brcmf_btcoex_params_read(struct brcmf_if *ifp, u32 addr, u32 *data)
122 {
123 	*data = addr;
124 
125 	return brcmf_fil_iovar_int_get(ifp, "btc_params", data);
126 }
127 
128 /**
129  * brcmf_btcoex_boost_wifi() - control BT SCO/eSCO parameters
130  * @btci: BT coex info
131  * @trump_sco:
132  *	true - set SCO/eSCO parameters for compatibility
133  *		during DHCP window
134  *	false - restore saved parameter values
135  *
136  * Enhanced BT COEX settings for eSCO compatibility during DHCP window
137  */
138 static void brcmf_btcoex_boost_wifi(struct brcmf_btcoex_info *btci,
139 				    bool trump_sco)
140 {
141 	struct brcmf_if *ifp = brcmf_get_ifp(btci->cfg->pub, 0);
142 
143 	if (trump_sco && !btci->saved_regs_part2) {
144 		/* this should reduce eSCO agressive
145 		 * retransmit w/o breaking it
146 		 */
147 
148 		/* save current */
149 		brcmf_dbg(INFO, "new SCO/eSCO coex algo {save & override}\n");
150 		brcmf_btcoex_params_read(ifp, 50, &btci->reg50);
151 		brcmf_btcoex_params_read(ifp, 51, &btci->reg51);
152 		brcmf_btcoex_params_read(ifp, 64, &btci->reg64);
153 		brcmf_btcoex_params_read(ifp, 65, &btci->reg65);
154 		brcmf_btcoex_params_read(ifp, 71, &btci->reg71);
155 
156 		btci->saved_regs_part2 = true;
157 		brcmf_dbg(INFO,
158 			  "saved bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
159 			  btci->reg50, btci->reg51, btci->reg64,
160 			  btci->reg65, btci->reg71);
161 
162 		/* pacify the eSco   */
163 		brcmf_btcoex_params_write(ifp, 50, BRCMF_BT_DHCP_REG50);
164 		brcmf_btcoex_params_write(ifp, 51, BRCMF_BT_DHCP_REG51);
165 		brcmf_btcoex_params_write(ifp, 64, BRCMF_BT_DHCP_REG64);
166 		brcmf_btcoex_params_write(ifp, 65, BRCMF_BT_DHCP_REG65);
167 		brcmf_btcoex_params_write(ifp, 71, BRCMF_BT_DHCP_REG71);
168 
169 	} else if (btci->saved_regs_part2) {
170 		/* restore previously saved bt params */
171 		brcmf_dbg(INFO, "Do new SCO/eSCO coex algo {restore}\n");
172 		brcmf_btcoex_params_write(ifp, 50, btci->reg50);
173 		brcmf_btcoex_params_write(ifp, 51, btci->reg51);
174 		brcmf_btcoex_params_write(ifp, 64, btci->reg64);
175 		brcmf_btcoex_params_write(ifp, 65, btci->reg65);
176 		brcmf_btcoex_params_write(ifp, 71, btci->reg71);
177 
178 		brcmf_dbg(INFO,
179 			  "restored bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
180 			  btci->reg50, btci->reg51, btci->reg64,
181 			  btci->reg65, btci->reg71);
182 
183 		btci->saved_regs_part2 = false;
184 	} else {
185 		brcmf_dbg(INFO, "attempted to restore not saved BTCOEX params\n");
186 	}
187 }
188 
189 /**
190  * brcmf_btcoex_is_sco_active() - check if SCO/eSCO is active
191  * @ifp: interface
192  *
193  * return: true if SCO/eSCO session is active
194  */
195 static bool brcmf_btcoex_is_sco_active(struct brcmf_if *ifp)
196 {
197 	int ioc_res = 0;
198 	bool res = false;
199 	int sco_id_cnt = 0;
200 	u32 param27;
201 	int i;
202 
203 	for (i = 0; i < BRCMF_BT_SCO_SAMPLES; i++) {
204 		ioc_res = brcmf_btcoex_params_read(ifp, 27, &param27);
205 
206 		if (ioc_res < 0) {
207 			brcmf_err("ioc read btc params error\n");
208 			break;
209 		}
210 
211 		brcmf_dbg(INFO, "sample[%d], btc_params 27:%x\n", i, param27);
212 
213 		if ((param27 & 0x6) == 2) { /* count both sco & esco  */
214 			sco_id_cnt++;
215 		}
216 
217 		if (sco_id_cnt > 2) {
218 			brcmf_dbg(INFO,
219 				  "sco/esco detected, pkt id_cnt:%d samples:%d\n",
220 				  sco_id_cnt, i);
221 			res = true;
222 			break;
223 		}
224 	}
225 	brcmf_dbg(TRACE, "exit: result=%d\n", res);
226 	return res;
227 }
228 
229 /**
230  * btcmf_btcoex_save_part1() - save first step parameters.
231  */
232 static void btcmf_btcoex_save_part1(struct brcmf_btcoex_info *btci)
233 {
234 	struct brcmf_if *ifp = btci->vif->ifp;
235 
236 	if (!btci->saved_regs_part1) {
237 		/* Retrieve and save original reg value */
238 		brcmf_btcoex_params_read(ifp, 66, &btci->reg66);
239 		brcmf_btcoex_params_read(ifp, 41, &btci->reg41);
240 		brcmf_btcoex_params_read(ifp, 68, &btci->reg68);
241 		btci->saved_regs_part1 = true;
242 		brcmf_dbg(INFO,
243 			  "saved btc_params regs (66,41,68) 0x%x 0x%x 0x%x\n",
244 			  btci->reg66, btci->reg41,
245 			  btci->reg68);
246 	}
247 }
248 
249 /**
250  * brcmf_btcoex_restore_part1() - restore first step parameters.
251  */
252 static void brcmf_btcoex_restore_part1(struct brcmf_btcoex_info *btci)
253 {
254 	struct brcmf_if *ifp;
255 
256 	if (btci->saved_regs_part1) {
257 		btci->saved_regs_part1 = false;
258 		ifp = btci->vif->ifp;
259 		brcmf_btcoex_params_write(ifp, 66, btci->reg66);
260 		brcmf_btcoex_params_write(ifp, 41, btci->reg41);
261 		brcmf_btcoex_params_write(ifp, 68, btci->reg68);
262 		brcmf_dbg(INFO,
263 			  "restored btc_params regs {66,41,68} 0x%x 0x%x 0x%x\n",
264 			  btci->reg66, btci->reg41,
265 			  btci->reg68);
266 	}
267 }
268 
269 /**
270  * brcmf_btcoex_timerfunc() - BT coex timer callback
271  */
272 static void brcmf_btcoex_timerfunc(struct timer_list *t)
273 {
274 	struct brcmf_btcoex_info *bt_local = from_timer(bt_local, t, timer);
275 	brcmf_dbg(TRACE, "enter\n");
276 
277 	bt_local->timer_on = false;
278 	schedule_work(&bt_local->work);
279 }
280 
281 /**
282  * brcmf_btcoex_handler() - BT coex state machine work handler
283  * @work: work
284  */
285 static void brcmf_btcoex_handler(struct work_struct *work)
286 {
287 	struct brcmf_btcoex_info *btci;
288 	btci = container_of(work, struct brcmf_btcoex_info, work);
289 	if (btci->timer_on) {
290 		btci->timer_on = false;
291 		del_timer_sync(&btci->timer);
292 	}
293 
294 	switch (btci->bt_state) {
295 	case BRCMF_BT_DHCP_START:
296 		/* DHCP started provide OPPORTUNITY window
297 		   to get DHCP address
298 		*/
299 		brcmf_dbg(INFO, "DHCP started\n");
300 		btci->bt_state = BRCMF_BT_DHCP_OPPR_WIN;
301 		if (btci->timeout < BRCMF_BTCOEX_OPPR_WIN_TIME) {
302 			mod_timer(&btci->timer, btci->timer.expires);
303 		} else {
304 			btci->timeout -= BRCMF_BTCOEX_OPPR_WIN_TIME;
305 			mod_timer(&btci->timer,
306 				  jiffies + BRCMF_BTCOEX_OPPR_WIN_TIME);
307 		}
308 		btci->timer_on = true;
309 		break;
310 
311 	case BRCMF_BT_DHCP_OPPR_WIN:
312 		if (btci->dhcp_done) {
313 			brcmf_dbg(INFO, "DHCP done before T1 expiration\n");
314 			goto idle;
315 		}
316 
317 		/* DHCP is not over yet, start lowering BT priority */
318 		brcmf_dbg(INFO, "DHCP T1:%d expired\n",
319 			  jiffies_to_msecs(BRCMF_BTCOEX_OPPR_WIN_TIME));
320 		brcmf_btcoex_boost_wifi(btci, true);
321 
322 		btci->bt_state = BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT;
323 		mod_timer(&btci->timer, jiffies + btci->timeout);
324 		btci->timer_on = true;
325 		break;
326 
327 	case BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT:
328 		if (btci->dhcp_done)
329 			brcmf_dbg(INFO, "DHCP done before T2 expiration\n");
330 		else
331 			brcmf_dbg(INFO, "DHCP T2:%d expired\n",
332 				  BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT);
333 
334 		goto idle;
335 
336 	default:
337 		brcmf_err("invalid state=%d !!!\n", btci->bt_state);
338 		goto idle;
339 	}
340 
341 	return;
342 
343 idle:
344 	btci->bt_state = BRCMF_BT_DHCP_IDLE;
345 	btci->timer_on = false;
346 	brcmf_btcoex_boost_wifi(btci, false);
347 	cfg80211_crit_proto_stopped(&btci->vif->wdev, GFP_KERNEL);
348 	brcmf_btcoex_restore_part1(btci);
349 	btci->vif = NULL;
350 }
351 
352 /**
353  * brcmf_btcoex_attach() - initialize BT coex data
354  * @cfg: driver private cfg80211 data
355  *
356  * return: 0 on success
357  */
358 int brcmf_btcoex_attach(struct brcmf_cfg80211_info *cfg)
359 {
360 	struct brcmf_btcoex_info *btci = NULL;
361 	brcmf_dbg(TRACE, "enter\n");
362 
363 	btci = kmalloc(sizeof(struct brcmf_btcoex_info), GFP_KERNEL);
364 	if (!btci)
365 		return -ENOMEM;
366 
367 	btci->bt_state = BRCMF_BT_DHCP_IDLE;
368 
369 	/* Set up timer for BT  */
370 	btci->timer_on = false;
371 	btci->timeout = BRCMF_BTCOEX_OPPR_WIN_TIME;
372 	timer_setup(&btci->timer, brcmf_btcoex_timerfunc, 0);
373 	btci->cfg = cfg;
374 	btci->saved_regs_part1 = false;
375 	btci->saved_regs_part2 = false;
376 
377 	INIT_WORK(&btci->work, brcmf_btcoex_handler);
378 
379 	cfg->btcoex = btci;
380 	return 0;
381 }
382 
383 /**
384  * brcmf_btcoex_detach - clean BT coex data
385  * @cfg: driver private cfg80211 data
386  */
387 void brcmf_btcoex_detach(struct brcmf_cfg80211_info *cfg)
388 {
389 	brcmf_dbg(TRACE, "enter\n");
390 
391 	if (!cfg->btcoex)
392 		return;
393 
394 	if (cfg->btcoex->timer_on) {
395 		cfg->btcoex->timer_on = false;
396 		del_timer_sync(&cfg->btcoex->timer);
397 	}
398 
399 	cancel_work_sync(&cfg->btcoex->work);
400 
401 	brcmf_btcoex_boost_wifi(cfg->btcoex, false);
402 	brcmf_btcoex_restore_part1(cfg->btcoex);
403 
404 	kfree(cfg->btcoex);
405 	cfg->btcoex = NULL;
406 }
407 
408 static void brcmf_btcoex_dhcp_start(struct brcmf_btcoex_info *btci)
409 {
410 	struct brcmf_if *ifp = btci->vif->ifp;
411 
412 	btcmf_btcoex_save_part1(btci);
413 	/* set new regs values */
414 	brcmf_btcoex_params_write(ifp, 66, BRCMF_BT_DHCP_REG66);
415 	brcmf_btcoex_params_write(ifp, 41, BRCMF_BT_DHCP_REG41);
416 	brcmf_btcoex_params_write(ifp, 68, BRCMF_BT_DHCP_REG68);
417 	btci->dhcp_done = false;
418 	btci->bt_state = BRCMF_BT_DHCP_START;
419 	schedule_work(&btci->work);
420 	brcmf_dbg(TRACE, "enable BT DHCP Timer\n");
421 }
422 
423 static void brcmf_btcoex_dhcp_end(struct brcmf_btcoex_info *btci)
424 {
425 	/* Stop any bt timer because DHCP session is done */
426 	btci->dhcp_done = true;
427 	if (btci->timer_on) {
428 		brcmf_dbg(INFO, "disable BT DHCP Timer\n");
429 		btci->timer_on = false;
430 		del_timer_sync(&btci->timer);
431 
432 		/* schedule worker if transition to IDLE is needed */
433 		if (btci->bt_state != BRCMF_BT_DHCP_IDLE) {
434 			brcmf_dbg(INFO, "bt_state:%d\n",
435 				  btci->bt_state);
436 			schedule_work(&btci->work);
437 		}
438 	} else {
439 		/* Restore original values */
440 		brcmf_btcoex_restore_part1(btci);
441 	}
442 }
443 
444 /**
445  * brcmf_btcoex_set_mode - set BT coex mode
446  * @cfg: driver private cfg80211 data
447  * @mode: Wifi-Bluetooth coexistence mode
448  *
449  * return: 0 on success
450  */
451 int brcmf_btcoex_set_mode(struct brcmf_cfg80211_vif *vif,
452 			  enum brcmf_btcoex_mode mode, u16 duration)
453 {
454 	struct brcmf_cfg80211_info *cfg = wiphy_to_cfg(vif->wdev.wiphy);
455 	struct brcmf_btcoex_info *btci = cfg->btcoex;
456 	struct brcmf_if *ifp = brcmf_get_ifp(cfg->pub, 0);
457 
458 	switch (mode) {
459 	case BRCMF_BTCOEX_DISABLED:
460 		brcmf_dbg(INFO, "DHCP session starts\n");
461 		if (btci->bt_state != BRCMF_BT_DHCP_IDLE)
462 			return -EBUSY;
463 		/* Start BT timer only for SCO connection */
464 		if (brcmf_btcoex_is_sco_active(ifp)) {
465 			btci->timeout = msecs_to_jiffies(duration);
466 			btci->vif = vif;
467 			brcmf_btcoex_dhcp_start(btci);
468 		}
469 		break;
470 
471 	case BRCMF_BTCOEX_ENABLED:
472 		brcmf_dbg(INFO, "DHCP session ends\n");
473 		if (btci->bt_state != BRCMF_BT_DHCP_IDLE &&
474 		    vif == btci->vif) {
475 			brcmf_btcoex_dhcp_end(btci);
476 		}
477 		break;
478 	default:
479 		brcmf_dbg(INFO, "Unknown mode, ignored\n");
480 	}
481 	return 0;
482 }
483