xref: /linux/drivers/net/wireless/broadcom/brcm80211/brcmfmac/btcoex.c (revision 96ac6d435100450f0565708d9b885ea2a7400e0a)
1 /*
2  * Copyright (c) 2013 Broadcom Corporation
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
11  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
13  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
14  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 #include <linux/slab.h>
17 #include <linux/netdevice.h>
18 #include <net/cfg80211.h>
19 
20 #include <brcmu_wifi.h>
21 #include <brcmu_utils.h>
22 #include <defs.h>
23 #include "core.h"
24 #include "debug.h"
25 #include "fwil.h"
26 #include "fwil_types.h"
27 #include "btcoex.h"
28 #include "p2p.h"
29 #include "cfg80211.h"
30 
31 /* T1 start SCO/eSCO priority suppression */
32 #define BRCMF_BTCOEX_OPPR_WIN_TIME   msecs_to_jiffies(2000)
33 
34 /* BT registers values during DHCP */
35 #define BRCMF_BT_DHCP_REG50 0x8022
36 #define BRCMF_BT_DHCP_REG51 0
37 #define BRCMF_BT_DHCP_REG64 0
38 #define BRCMF_BT_DHCP_REG65 0
39 #define BRCMF_BT_DHCP_REG71 0
40 #define BRCMF_BT_DHCP_REG66 0x2710
41 #define BRCMF_BT_DHCP_REG41 0x33
42 #define BRCMF_BT_DHCP_REG68 0x190
43 
44 /* number of samples for SCO detection */
45 #define BRCMF_BT_SCO_SAMPLES 12
46 
47 /**
48 * enum brcmf_btcoex_state - BT coex DHCP state machine states
49 * @BRCMF_BT_DHCP_IDLE: DCHP is idle
50 * @BRCMF_BT_DHCP_START: DHCP started, wait before
51 *	boosting wifi priority
52 * @BRCMF_BT_DHCP_OPPR_WIN: graceful DHCP opportunity ended,
53 *	boost wifi priority
54 * @BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT: wifi priority boost end,
55 *	restore defaults
56 */
57 enum brcmf_btcoex_state {
58 	BRCMF_BT_DHCP_IDLE,
59 	BRCMF_BT_DHCP_START,
60 	BRCMF_BT_DHCP_OPPR_WIN,
61 	BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT
62 };
63 
64 /**
65  * struct brcmf_btcoex_info - BT coex related information
66  * @vif: interface for which request was done.
67  * @timer: timer for DHCP state machine
68  * @timeout: configured timeout.
69  * @timer_on:  DHCP timer active
70  * @dhcp_done: DHCP finished before T1/T2 timer expiration
71  * @bt_state: DHCP state machine state
72  * @work: DHCP state machine work
73  * @cfg: driver private data for cfg80211 interface
74  * @reg66: saved value of btc_params 66
75  * @reg41: saved value of btc_params 41
76  * @reg68: saved value of btc_params 68
77  * @saved_regs_part1: flag indicating regs 66,41,68
78  *	have been saved
79  * @reg51: saved value of btc_params 51
80  * @reg64: saved value of btc_params 64
81  * @reg65: saved value of btc_params 65
82  * @reg71: saved value of btc_params 71
83  * @saved_regs_part1: flag indicating regs 50,51,64,65,71
84  *	have been saved
85  */
86 struct brcmf_btcoex_info {
87 	struct brcmf_cfg80211_vif *vif;
88 	struct timer_list timer;
89 	u16 timeout;
90 	bool timer_on;
91 	bool dhcp_done;
92 	enum brcmf_btcoex_state bt_state;
93 	struct work_struct work;
94 	struct brcmf_cfg80211_info *cfg;
95 	u32 reg66;
96 	u32 reg41;
97 	u32 reg68;
98 	bool saved_regs_part1;
99 	u32 reg50;
100 	u32 reg51;
101 	u32 reg64;
102 	u32 reg65;
103 	u32 reg71;
104 	bool saved_regs_part2;
105 };
106 
107 /**
108  * brcmf_btcoex_params_write() - write btc_params firmware variable
109  * @ifp: interface
110  * @addr: btc_params register number
111  * @data: data to write
112  */
113 static s32 brcmf_btcoex_params_write(struct brcmf_if *ifp, u32 addr, u32 data)
114 {
115 	struct {
116 		__le32 addr;
117 		__le32 data;
118 	} reg_write;
119 
120 	reg_write.addr = cpu_to_le32(addr);
121 	reg_write.data = cpu_to_le32(data);
122 	return brcmf_fil_iovar_data_set(ifp, "btc_params",
123 					&reg_write, sizeof(reg_write));
124 }
125 
126 /**
127  * brcmf_btcoex_params_read() - read btc_params firmware variable
128  * @ifp: interface
129  * @addr: btc_params register number
130  * @data: read data
131  */
132 static s32 brcmf_btcoex_params_read(struct brcmf_if *ifp, u32 addr, u32 *data)
133 {
134 	*data = addr;
135 
136 	return brcmf_fil_iovar_int_get(ifp, "btc_params", data);
137 }
138 
139 /**
140  * brcmf_btcoex_boost_wifi() - control BT SCO/eSCO parameters
141  * @btci: BT coex info
142  * @trump_sco:
143  *	true - set SCO/eSCO parameters for compatibility
144  *		during DHCP window
145  *	false - restore saved parameter values
146  *
147  * Enhanced BT COEX settings for eSCO compatibility during DHCP window
148  */
149 static void brcmf_btcoex_boost_wifi(struct brcmf_btcoex_info *btci,
150 				    bool trump_sco)
151 {
152 	struct brcmf_if *ifp = brcmf_get_ifp(btci->cfg->pub, 0);
153 
154 	if (trump_sco && !btci->saved_regs_part2) {
155 		/* this should reduce eSCO agressive
156 		 * retransmit w/o breaking it
157 		 */
158 
159 		/* save current */
160 		brcmf_dbg(INFO, "new SCO/eSCO coex algo {save & override}\n");
161 		brcmf_btcoex_params_read(ifp, 50, &btci->reg50);
162 		brcmf_btcoex_params_read(ifp, 51, &btci->reg51);
163 		brcmf_btcoex_params_read(ifp, 64, &btci->reg64);
164 		brcmf_btcoex_params_read(ifp, 65, &btci->reg65);
165 		brcmf_btcoex_params_read(ifp, 71, &btci->reg71);
166 
167 		btci->saved_regs_part2 = true;
168 		brcmf_dbg(INFO,
169 			  "saved bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
170 			  btci->reg50, btci->reg51, btci->reg64,
171 			  btci->reg65, btci->reg71);
172 
173 		/* pacify the eSco   */
174 		brcmf_btcoex_params_write(ifp, 50, BRCMF_BT_DHCP_REG50);
175 		brcmf_btcoex_params_write(ifp, 51, BRCMF_BT_DHCP_REG51);
176 		brcmf_btcoex_params_write(ifp, 64, BRCMF_BT_DHCP_REG64);
177 		brcmf_btcoex_params_write(ifp, 65, BRCMF_BT_DHCP_REG65);
178 		brcmf_btcoex_params_write(ifp, 71, BRCMF_BT_DHCP_REG71);
179 
180 	} else if (btci->saved_regs_part2) {
181 		/* restore previously saved bt params */
182 		brcmf_dbg(INFO, "Do new SCO/eSCO coex algo {restore}\n");
183 		brcmf_btcoex_params_write(ifp, 50, btci->reg50);
184 		brcmf_btcoex_params_write(ifp, 51, btci->reg51);
185 		brcmf_btcoex_params_write(ifp, 64, btci->reg64);
186 		brcmf_btcoex_params_write(ifp, 65, btci->reg65);
187 		brcmf_btcoex_params_write(ifp, 71, btci->reg71);
188 
189 		brcmf_dbg(INFO,
190 			  "restored bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
191 			  btci->reg50, btci->reg51, btci->reg64,
192 			  btci->reg65, btci->reg71);
193 
194 		btci->saved_regs_part2 = false;
195 	} else {
196 		brcmf_dbg(INFO, "attempted to restore not saved BTCOEX params\n");
197 	}
198 }
199 
200 /**
201  * brcmf_btcoex_is_sco_active() - check if SCO/eSCO is active
202  * @ifp: interface
203  *
204  * return: true if SCO/eSCO session is active
205  */
206 static bool brcmf_btcoex_is_sco_active(struct brcmf_if *ifp)
207 {
208 	int ioc_res = 0;
209 	bool res = false;
210 	int sco_id_cnt = 0;
211 	u32 param27;
212 	int i;
213 
214 	for (i = 0; i < BRCMF_BT_SCO_SAMPLES; i++) {
215 		ioc_res = brcmf_btcoex_params_read(ifp, 27, &param27);
216 
217 		if (ioc_res < 0) {
218 			brcmf_err("ioc read btc params error\n");
219 			break;
220 		}
221 
222 		brcmf_dbg(INFO, "sample[%d], btc_params 27:%x\n", i, param27);
223 
224 		if ((param27 & 0x6) == 2) { /* count both sco & esco  */
225 			sco_id_cnt++;
226 		}
227 
228 		if (sco_id_cnt > 2) {
229 			brcmf_dbg(INFO,
230 				  "sco/esco detected, pkt id_cnt:%d samples:%d\n",
231 				  sco_id_cnt, i);
232 			res = true;
233 			break;
234 		}
235 	}
236 	brcmf_dbg(TRACE, "exit: result=%d\n", res);
237 	return res;
238 }
239 
240 /**
241  * btcmf_btcoex_save_part1() - save first step parameters.
242  */
243 static void btcmf_btcoex_save_part1(struct brcmf_btcoex_info *btci)
244 {
245 	struct brcmf_if *ifp = btci->vif->ifp;
246 
247 	if (!btci->saved_regs_part1) {
248 		/* Retrieve and save original reg value */
249 		brcmf_btcoex_params_read(ifp, 66, &btci->reg66);
250 		brcmf_btcoex_params_read(ifp, 41, &btci->reg41);
251 		brcmf_btcoex_params_read(ifp, 68, &btci->reg68);
252 		btci->saved_regs_part1 = true;
253 		brcmf_dbg(INFO,
254 			  "saved btc_params regs (66,41,68) 0x%x 0x%x 0x%x\n",
255 			  btci->reg66, btci->reg41,
256 			  btci->reg68);
257 	}
258 }
259 
260 /**
261  * brcmf_btcoex_restore_part1() - restore first step parameters.
262  */
263 static void brcmf_btcoex_restore_part1(struct brcmf_btcoex_info *btci)
264 {
265 	struct brcmf_if *ifp;
266 
267 	if (btci->saved_regs_part1) {
268 		btci->saved_regs_part1 = false;
269 		ifp = btci->vif->ifp;
270 		brcmf_btcoex_params_write(ifp, 66, btci->reg66);
271 		brcmf_btcoex_params_write(ifp, 41, btci->reg41);
272 		brcmf_btcoex_params_write(ifp, 68, btci->reg68);
273 		brcmf_dbg(INFO,
274 			  "restored btc_params regs {66,41,68} 0x%x 0x%x 0x%x\n",
275 			  btci->reg66, btci->reg41,
276 			  btci->reg68);
277 	}
278 }
279 
280 /**
281  * brcmf_btcoex_timerfunc() - BT coex timer callback
282  */
283 static void brcmf_btcoex_timerfunc(struct timer_list *t)
284 {
285 	struct brcmf_btcoex_info *bt_local = from_timer(bt_local, t, timer);
286 	brcmf_dbg(TRACE, "enter\n");
287 
288 	bt_local->timer_on = false;
289 	schedule_work(&bt_local->work);
290 }
291 
292 /**
293  * brcmf_btcoex_handler() - BT coex state machine work handler
294  * @work: work
295  */
296 static void brcmf_btcoex_handler(struct work_struct *work)
297 {
298 	struct brcmf_btcoex_info *btci;
299 	btci = container_of(work, struct brcmf_btcoex_info, work);
300 	if (btci->timer_on) {
301 		btci->timer_on = false;
302 		del_timer_sync(&btci->timer);
303 	}
304 
305 	switch (btci->bt_state) {
306 	case BRCMF_BT_DHCP_START:
307 		/* DHCP started provide OPPORTUNITY window
308 		   to get DHCP address
309 		*/
310 		brcmf_dbg(INFO, "DHCP started\n");
311 		btci->bt_state = BRCMF_BT_DHCP_OPPR_WIN;
312 		if (btci->timeout < BRCMF_BTCOEX_OPPR_WIN_TIME) {
313 			mod_timer(&btci->timer, btci->timer.expires);
314 		} else {
315 			btci->timeout -= BRCMF_BTCOEX_OPPR_WIN_TIME;
316 			mod_timer(&btci->timer,
317 				  jiffies + BRCMF_BTCOEX_OPPR_WIN_TIME);
318 		}
319 		btci->timer_on = true;
320 		break;
321 
322 	case BRCMF_BT_DHCP_OPPR_WIN:
323 		if (btci->dhcp_done) {
324 			brcmf_dbg(INFO, "DHCP done before T1 expiration\n");
325 			goto idle;
326 		}
327 
328 		/* DHCP is not over yet, start lowering BT priority */
329 		brcmf_dbg(INFO, "DHCP T1:%d expired\n",
330 			  jiffies_to_msecs(BRCMF_BTCOEX_OPPR_WIN_TIME));
331 		brcmf_btcoex_boost_wifi(btci, true);
332 
333 		btci->bt_state = BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT;
334 		mod_timer(&btci->timer, jiffies + btci->timeout);
335 		btci->timer_on = true;
336 		break;
337 
338 	case BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT:
339 		if (btci->dhcp_done)
340 			brcmf_dbg(INFO, "DHCP done before T2 expiration\n");
341 		else
342 			brcmf_dbg(INFO, "DHCP T2:%d expired\n",
343 				  BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT);
344 
345 		goto idle;
346 
347 	default:
348 		brcmf_err("invalid state=%d !!!\n", btci->bt_state);
349 		goto idle;
350 	}
351 
352 	return;
353 
354 idle:
355 	btci->bt_state = BRCMF_BT_DHCP_IDLE;
356 	btci->timer_on = false;
357 	brcmf_btcoex_boost_wifi(btci, false);
358 	cfg80211_crit_proto_stopped(&btci->vif->wdev, GFP_KERNEL);
359 	brcmf_btcoex_restore_part1(btci);
360 	btci->vif = NULL;
361 }
362 
363 /**
364  * brcmf_btcoex_attach() - initialize BT coex data
365  * @cfg: driver private cfg80211 data
366  *
367  * return: 0 on success
368  */
369 int brcmf_btcoex_attach(struct brcmf_cfg80211_info *cfg)
370 {
371 	struct brcmf_btcoex_info *btci = NULL;
372 	brcmf_dbg(TRACE, "enter\n");
373 
374 	btci = kmalloc(sizeof(struct brcmf_btcoex_info), GFP_KERNEL);
375 	if (!btci)
376 		return -ENOMEM;
377 
378 	btci->bt_state = BRCMF_BT_DHCP_IDLE;
379 
380 	/* Set up timer for BT  */
381 	btci->timer_on = false;
382 	btci->timeout = BRCMF_BTCOEX_OPPR_WIN_TIME;
383 	timer_setup(&btci->timer, brcmf_btcoex_timerfunc, 0);
384 	btci->cfg = cfg;
385 	btci->saved_regs_part1 = false;
386 	btci->saved_regs_part2 = false;
387 
388 	INIT_WORK(&btci->work, brcmf_btcoex_handler);
389 
390 	cfg->btcoex = btci;
391 	return 0;
392 }
393 
394 /**
395  * brcmf_btcoex_detach - clean BT coex data
396  * @cfg: driver private cfg80211 data
397  */
398 void brcmf_btcoex_detach(struct brcmf_cfg80211_info *cfg)
399 {
400 	brcmf_dbg(TRACE, "enter\n");
401 
402 	if (!cfg->btcoex)
403 		return;
404 
405 	if (cfg->btcoex->timer_on) {
406 		cfg->btcoex->timer_on = false;
407 		del_timer_sync(&cfg->btcoex->timer);
408 	}
409 
410 	cancel_work_sync(&cfg->btcoex->work);
411 
412 	brcmf_btcoex_boost_wifi(cfg->btcoex, false);
413 	brcmf_btcoex_restore_part1(cfg->btcoex);
414 
415 	kfree(cfg->btcoex);
416 	cfg->btcoex = NULL;
417 }
418 
419 static void brcmf_btcoex_dhcp_start(struct brcmf_btcoex_info *btci)
420 {
421 	struct brcmf_if *ifp = btci->vif->ifp;
422 
423 	btcmf_btcoex_save_part1(btci);
424 	/* set new regs values */
425 	brcmf_btcoex_params_write(ifp, 66, BRCMF_BT_DHCP_REG66);
426 	brcmf_btcoex_params_write(ifp, 41, BRCMF_BT_DHCP_REG41);
427 	brcmf_btcoex_params_write(ifp, 68, BRCMF_BT_DHCP_REG68);
428 	btci->dhcp_done = false;
429 	btci->bt_state = BRCMF_BT_DHCP_START;
430 	schedule_work(&btci->work);
431 	brcmf_dbg(TRACE, "enable BT DHCP Timer\n");
432 }
433 
434 static void brcmf_btcoex_dhcp_end(struct brcmf_btcoex_info *btci)
435 {
436 	/* Stop any bt timer because DHCP session is done */
437 	btci->dhcp_done = true;
438 	if (btci->timer_on) {
439 		brcmf_dbg(INFO, "disable BT DHCP Timer\n");
440 		btci->timer_on = false;
441 		del_timer_sync(&btci->timer);
442 
443 		/* schedule worker if transition to IDLE is needed */
444 		if (btci->bt_state != BRCMF_BT_DHCP_IDLE) {
445 			brcmf_dbg(INFO, "bt_state:%d\n",
446 				  btci->bt_state);
447 			schedule_work(&btci->work);
448 		}
449 	} else {
450 		/* Restore original values */
451 		brcmf_btcoex_restore_part1(btci);
452 	}
453 }
454 
455 /**
456  * brcmf_btcoex_set_mode - set BT coex mode
457  * @cfg: driver private cfg80211 data
458  * @mode: Wifi-Bluetooth coexistence mode
459  *
460  * return: 0 on success
461  */
462 int brcmf_btcoex_set_mode(struct brcmf_cfg80211_vif *vif,
463 			  enum brcmf_btcoex_mode mode, u16 duration)
464 {
465 	struct brcmf_cfg80211_info *cfg = wiphy_to_cfg(vif->wdev.wiphy);
466 	struct brcmf_btcoex_info *btci = cfg->btcoex;
467 	struct brcmf_if *ifp = brcmf_get_ifp(cfg->pub, 0);
468 
469 	switch (mode) {
470 	case BRCMF_BTCOEX_DISABLED:
471 		brcmf_dbg(INFO, "DHCP session starts\n");
472 		if (btci->bt_state != BRCMF_BT_DHCP_IDLE)
473 			return -EBUSY;
474 		/* Start BT timer only for SCO connection */
475 		if (brcmf_btcoex_is_sco_active(ifp)) {
476 			btci->timeout = msecs_to_jiffies(duration);
477 			btci->vif = vif;
478 			brcmf_btcoex_dhcp_start(btci);
479 		}
480 		break;
481 
482 	case BRCMF_BTCOEX_ENABLED:
483 		brcmf_dbg(INFO, "DHCP session ends\n");
484 		if (btci->bt_state != BRCMF_BT_DHCP_IDLE &&
485 		    vif == btci->vif) {
486 			brcmf_btcoex_dhcp_end(btci);
487 		}
488 		break;
489 	default:
490 		brcmf_dbg(INFO, "Unknown mode, ignored\n");
491 	}
492 	return 0;
493 }
494