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  * @reg50: saved value of btc_params 50
69  * @reg51: saved value of btc_params 51
70  * @reg64: saved value of btc_params 64
71  * @reg65: saved value of btc_params 65
72  * @reg71: saved value of btc_params 71
73  * @saved_regs_part2: flag indicating regs 50,51,64,65,71
74  *	have been saved
75  */
76 struct brcmf_btcoex_info {
77 	struct brcmf_cfg80211_vif *vif;
78 	struct timer_list timer;
79 	u16 timeout;
80 	bool timer_on;
81 	bool dhcp_done;
82 	enum brcmf_btcoex_state bt_state;
83 	struct work_struct work;
84 	struct brcmf_cfg80211_info *cfg;
85 	u32 reg66;
86 	u32 reg41;
87 	u32 reg68;
88 	bool saved_regs_part1;
89 	u32 reg50;
90 	u32 reg51;
91 	u32 reg64;
92 	u32 reg65;
93 	u32 reg71;
94 	bool saved_regs_part2;
95 };
96 
97 /**
98  * brcmf_btcoex_params_write() - write btc_params firmware variable
99  * @ifp: interface
100  * @addr: btc_params register number
101  * @data: data to write
102  */
103 static s32 brcmf_btcoex_params_write(struct brcmf_if *ifp, u32 addr, u32 data)
104 {
105 	struct {
106 		__le32 addr;
107 		__le32 data;
108 	} reg_write;
109 
110 	reg_write.addr = cpu_to_le32(addr);
111 	reg_write.data = cpu_to_le32(data);
112 	return brcmf_fil_iovar_data_set(ifp, "btc_params",
113 					&reg_write, sizeof(reg_write));
114 }
115 
116 /**
117  * brcmf_btcoex_params_read() - read btc_params firmware variable
118  * @ifp: interface
119  * @addr: btc_params register number
120  * @data: read data
121  */
122 static s32 brcmf_btcoex_params_read(struct brcmf_if *ifp, u32 addr, u32 *data)
123 {
124 	*data = addr;
125 
126 	return brcmf_fil_iovar_int_get(ifp, "btc_params", data);
127 }
128 
129 /**
130  * brcmf_btcoex_boost_wifi() - control BT SCO/eSCO parameters
131  * @btci: BT coex info
132  * @trump_sco:
133  *	true - set SCO/eSCO parameters for compatibility
134  *		during DHCP window
135  *	false - restore saved parameter values
136  *
137  * Enhanced BT COEX settings for eSCO compatibility during DHCP window
138  */
139 static void brcmf_btcoex_boost_wifi(struct brcmf_btcoex_info *btci,
140 				    bool trump_sco)
141 {
142 	struct brcmf_if *ifp = brcmf_get_ifp(btci->cfg->pub, 0);
143 
144 	if (trump_sco && !btci->saved_regs_part2) {
145 		/* this should reduce eSCO agressive
146 		 * retransmit w/o breaking it
147 		 */
148 
149 		/* save current */
150 		brcmf_dbg(INFO, "new SCO/eSCO coex algo {save & override}\n");
151 		brcmf_btcoex_params_read(ifp, 50, &btci->reg50);
152 		brcmf_btcoex_params_read(ifp, 51, &btci->reg51);
153 		brcmf_btcoex_params_read(ifp, 64, &btci->reg64);
154 		brcmf_btcoex_params_read(ifp, 65, &btci->reg65);
155 		brcmf_btcoex_params_read(ifp, 71, &btci->reg71);
156 
157 		btci->saved_regs_part2 = true;
158 		brcmf_dbg(INFO,
159 			  "saved bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
160 			  btci->reg50, btci->reg51, btci->reg64,
161 			  btci->reg65, btci->reg71);
162 
163 		/* pacify the eSco   */
164 		brcmf_btcoex_params_write(ifp, 50, BRCMF_BT_DHCP_REG50);
165 		brcmf_btcoex_params_write(ifp, 51, BRCMF_BT_DHCP_REG51);
166 		brcmf_btcoex_params_write(ifp, 64, BRCMF_BT_DHCP_REG64);
167 		brcmf_btcoex_params_write(ifp, 65, BRCMF_BT_DHCP_REG65);
168 		brcmf_btcoex_params_write(ifp, 71, BRCMF_BT_DHCP_REG71);
169 
170 	} else if (btci->saved_regs_part2) {
171 		/* restore previously saved bt params */
172 		brcmf_dbg(INFO, "Do new SCO/eSCO coex algo {restore}\n");
173 		brcmf_btcoex_params_write(ifp, 50, btci->reg50);
174 		brcmf_btcoex_params_write(ifp, 51, btci->reg51);
175 		brcmf_btcoex_params_write(ifp, 64, btci->reg64);
176 		brcmf_btcoex_params_write(ifp, 65, btci->reg65);
177 		brcmf_btcoex_params_write(ifp, 71, btci->reg71);
178 
179 		brcmf_dbg(INFO,
180 			  "restored bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
181 			  btci->reg50, btci->reg51, btci->reg64,
182 			  btci->reg65, btci->reg71);
183 
184 		btci->saved_regs_part2 = false;
185 	} else {
186 		brcmf_dbg(INFO, "attempted to restore not saved BTCOEX params\n");
187 	}
188 }
189 
190 /**
191  * brcmf_btcoex_is_sco_active() - check if SCO/eSCO is active
192  * @ifp: interface
193  *
194  * return: true if SCO/eSCO session is active
195  */
196 static bool brcmf_btcoex_is_sco_active(struct brcmf_if *ifp)
197 {
198 	int ioc_res = 0;
199 	bool res = false;
200 	int sco_id_cnt = 0;
201 	u32 param27;
202 	int i;
203 
204 	for (i = 0; i < BRCMF_BT_SCO_SAMPLES; i++) {
205 		ioc_res = brcmf_btcoex_params_read(ifp, 27, &param27);
206 
207 		if (ioc_res < 0) {
208 			brcmf_err("ioc read btc params error\n");
209 			break;
210 		}
211 
212 		brcmf_dbg(INFO, "sample[%d], btc_params 27:%x\n", i, param27);
213 
214 		if ((param27 & 0x6) == 2) { /* count both sco & esco  */
215 			sco_id_cnt++;
216 		}
217 
218 		if (sco_id_cnt > 2) {
219 			brcmf_dbg(INFO,
220 				  "sco/esco detected, pkt id_cnt:%d samples:%d\n",
221 				  sco_id_cnt, i);
222 			res = true;
223 			break;
224 		}
225 	}
226 	brcmf_dbg(TRACE, "exit: result=%d\n", res);
227 	return res;
228 }
229 
230 /*
231  * btcmf_btcoex_save_part1() - save first step parameters.
232  */
233 static void btcmf_btcoex_save_part1(struct brcmf_btcoex_info *btci)
234 {
235 	struct brcmf_if *ifp = btci->vif->ifp;
236 
237 	if (!btci->saved_regs_part1) {
238 		/* Retrieve and save original reg value */
239 		brcmf_btcoex_params_read(ifp, 66, &btci->reg66);
240 		brcmf_btcoex_params_read(ifp, 41, &btci->reg41);
241 		brcmf_btcoex_params_read(ifp, 68, &btci->reg68);
242 		btci->saved_regs_part1 = true;
243 		brcmf_dbg(INFO,
244 			  "saved btc_params regs (66,41,68) 0x%x 0x%x 0x%x\n",
245 			  btci->reg66, btci->reg41,
246 			  btci->reg68);
247 	}
248 }
249 
250 /*
251  * brcmf_btcoex_restore_part1() - restore first step parameters.
252  */
253 static void brcmf_btcoex_restore_part1(struct brcmf_btcoex_info *btci)
254 {
255 	struct brcmf_if *ifp;
256 
257 	if (btci->saved_regs_part1) {
258 		btci->saved_regs_part1 = false;
259 		ifp = btci->vif->ifp;
260 		brcmf_btcoex_params_write(ifp, 66, btci->reg66);
261 		brcmf_btcoex_params_write(ifp, 41, btci->reg41);
262 		brcmf_btcoex_params_write(ifp, 68, btci->reg68);
263 		brcmf_dbg(INFO,
264 			  "restored btc_params regs {66,41,68} 0x%x 0x%x 0x%x\n",
265 			  btci->reg66, btci->reg41,
266 			  btci->reg68);
267 	}
268 }
269 
270 /*
271  * brcmf_btcoex_timerfunc() - BT coex timer callback
272  */
273 static void brcmf_btcoex_timerfunc(struct timer_list *t)
274 {
275 	struct brcmf_btcoex_info *bt_local = from_timer(bt_local, t, timer);
276 	brcmf_dbg(TRACE, "enter\n");
277 
278 	bt_local->timer_on = false;
279 	schedule_work(&bt_local->work);
280 }
281 
282 /**
283  * brcmf_btcoex_handler() - BT coex state machine work handler
284  * @work: work
285  */
286 static void brcmf_btcoex_handler(struct work_struct *work)
287 {
288 	struct brcmf_btcoex_info *btci;
289 	btci = container_of(work, struct brcmf_btcoex_info, work);
290 	if (btci->timer_on) {
291 		btci->timer_on = false;
292 		del_timer_sync(&btci->timer);
293 	}
294 
295 	switch (btci->bt_state) {
296 	case BRCMF_BT_DHCP_START:
297 		/* DHCP started provide OPPORTUNITY window
298 		   to get DHCP address
299 		*/
300 		brcmf_dbg(INFO, "DHCP started\n");
301 		btci->bt_state = BRCMF_BT_DHCP_OPPR_WIN;
302 		if (btci->timeout < BRCMF_BTCOEX_OPPR_WIN_TIME) {
303 			mod_timer(&btci->timer, btci->timer.expires);
304 		} else {
305 			btci->timeout -= BRCMF_BTCOEX_OPPR_WIN_TIME;
306 			mod_timer(&btci->timer,
307 				  jiffies + BRCMF_BTCOEX_OPPR_WIN_TIME);
308 		}
309 		btci->timer_on = true;
310 		break;
311 
312 	case BRCMF_BT_DHCP_OPPR_WIN:
313 		if (btci->dhcp_done) {
314 			brcmf_dbg(INFO, "DHCP done before T1 expiration\n");
315 			goto idle;
316 		}
317 
318 		/* DHCP is not over yet, start lowering BT priority */
319 		brcmf_dbg(INFO, "DHCP T1:%d expired\n",
320 			  jiffies_to_msecs(BRCMF_BTCOEX_OPPR_WIN_TIME));
321 		brcmf_btcoex_boost_wifi(btci, true);
322 
323 		btci->bt_state = BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT;
324 		mod_timer(&btci->timer, jiffies + btci->timeout);
325 		btci->timer_on = true;
326 		break;
327 
328 	case BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT:
329 		if (btci->dhcp_done)
330 			brcmf_dbg(INFO, "DHCP done before T2 expiration\n");
331 		else
332 			brcmf_dbg(INFO, "DHCP T2:%d expired\n",
333 				  BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT);
334 
335 		goto idle;
336 
337 	default:
338 		brcmf_err("invalid state=%d !!!\n", btci->bt_state);
339 		goto idle;
340 	}
341 
342 	return;
343 
344 idle:
345 	btci->bt_state = BRCMF_BT_DHCP_IDLE;
346 	btci->timer_on = false;
347 	brcmf_btcoex_boost_wifi(btci, false);
348 	cfg80211_crit_proto_stopped(&btci->vif->wdev, GFP_KERNEL);
349 	brcmf_btcoex_restore_part1(btci);
350 	btci->vif = NULL;
351 }
352 
353 /**
354  * brcmf_btcoex_attach() - initialize BT coex data
355  * @cfg: driver private cfg80211 data
356  *
357  * return: 0 on success
358  */
359 int brcmf_btcoex_attach(struct brcmf_cfg80211_info *cfg)
360 {
361 	struct brcmf_btcoex_info *btci = NULL;
362 	brcmf_dbg(TRACE, "enter\n");
363 
364 	btci = kmalloc(sizeof(struct brcmf_btcoex_info), GFP_KERNEL);
365 	if (!btci)
366 		return -ENOMEM;
367 
368 	btci->bt_state = BRCMF_BT_DHCP_IDLE;
369 
370 	/* Set up timer for BT  */
371 	btci->timer_on = false;
372 	btci->timeout = BRCMF_BTCOEX_OPPR_WIN_TIME;
373 	timer_setup(&btci->timer, brcmf_btcoex_timerfunc, 0);
374 	btci->cfg = cfg;
375 	btci->saved_regs_part1 = false;
376 	btci->saved_regs_part2 = false;
377 
378 	INIT_WORK(&btci->work, brcmf_btcoex_handler);
379 
380 	cfg->btcoex = btci;
381 	return 0;
382 }
383 
384 /**
385  * brcmf_btcoex_detach - clean BT coex data
386  * @cfg: driver private cfg80211 data
387  */
388 void brcmf_btcoex_detach(struct brcmf_cfg80211_info *cfg)
389 {
390 	brcmf_dbg(TRACE, "enter\n");
391 
392 	if (!cfg->btcoex)
393 		return;
394 
395 	if (cfg->btcoex->timer_on) {
396 		cfg->btcoex->timer_on = false;
397 		timer_shutdown_sync(&cfg->btcoex->timer);
398 	}
399 
400 	cancel_work_sync(&cfg->btcoex->work);
401 
402 	brcmf_btcoex_boost_wifi(cfg->btcoex, false);
403 	brcmf_btcoex_restore_part1(cfg->btcoex);
404 
405 	kfree(cfg->btcoex);
406 	cfg->btcoex = NULL;
407 }
408 
409 static void brcmf_btcoex_dhcp_start(struct brcmf_btcoex_info *btci)
410 {
411 	struct brcmf_if *ifp = btci->vif->ifp;
412 
413 	btcmf_btcoex_save_part1(btci);
414 	/* set new regs values */
415 	brcmf_btcoex_params_write(ifp, 66, BRCMF_BT_DHCP_REG66);
416 	brcmf_btcoex_params_write(ifp, 41, BRCMF_BT_DHCP_REG41);
417 	brcmf_btcoex_params_write(ifp, 68, BRCMF_BT_DHCP_REG68);
418 	btci->dhcp_done = false;
419 	btci->bt_state = BRCMF_BT_DHCP_START;
420 	schedule_work(&btci->work);
421 	brcmf_dbg(TRACE, "enable BT DHCP Timer\n");
422 }
423 
424 static void brcmf_btcoex_dhcp_end(struct brcmf_btcoex_info *btci)
425 {
426 	/* Stop any bt timer because DHCP session is done */
427 	btci->dhcp_done = true;
428 	if (btci->timer_on) {
429 		brcmf_dbg(INFO, "disable BT DHCP Timer\n");
430 		btci->timer_on = false;
431 		del_timer_sync(&btci->timer);
432 
433 		/* schedule worker if transition to IDLE is needed */
434 		if (btci->bt_state != BRCMF_BT_DHCP_IDLE) {
435 			brcmf_dbg(INFO, "bt_state:%d\n",
436 				  btci->bt_state);
437 			schedule_work(&btci->work);
438 		}
439 	} else {
440 		/* Restore original values */
441 		brcmf_btcoex_restore_part1(btci);
442 	}
443 }
444 
445 /*
446  * brcmf_btcoex_set_mode - set BT coex mode
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