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   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*/
57enum 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 */
86struct 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 */
113static 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 */
132static 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 */
149static void brcmf_btcoex_boost_wifi(struct brcmf_btcoex_info *btci,
150				    bool trump_sco)
151{
152	struct brcmf_if *ifp = btci->cfg->pub->iflist[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 */
206static 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 */
243static 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 */
263static 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 */
283static void brcmf_btcoex_timerfunc(ulong data)
284{
285	struct brcmf_btcoex_info *bt_local = (struct brcmf_btcoex_info *)data;
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 */
296static 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 +
318				  msecs_to_jiffies(BRCMF_BTCOEX_OPPR_WIN_TIME));
319		}
320		btci->timer_on = true;
321		break;
322
323	case BRCMF_BT_DHCP_OPPR_WIN:
324		if (btci->dhcp_done) {
325			brcmf_dbg(INFO, "DHCP done before T1 expiration\n");
326			goto idle;
327		}
328
329		/* DHCP is not over yet, start lowering BT priority */
330		brcmf_dbg(INFO, "DHCP T1:%d expired\n",
331			  BRCMF_BTCOEX_OPPR_WIN_TIME);
332		brcmf_btcoex_boost_wifi(btci, true);
333
334		btci->bt_state = BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT;
335		mod_timer(&btci->timer,
336			  jiffies + msecs_to_jiffies(btci->timeout));
337		btci->timer_on = true;
338		break;
339
340	case BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT:
341		if (btci->dhcp_done)
342			brcmf_dbg(INFO, "DHCP done before T2 expiration\n");
343		else
344			brcmf_dbg(INFO, "DHCP T2:%d expired\n",
345				  BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT);
346
347		goto idle;
348
349	default:
350		brcmf_err("invalid state=%d !!!\n", btci->bt_state);
351		goto idle;
352	}
353
354	return;
355
356idle:
357	btci->bt_state = BRCMF_BT_DHCP_IDLE;
358	btci->timer_on = false;
359	brcmf_btcoex_boost_wifi(btci, false);
360	cfg80211_crit_proto_stopped(&btci->vif->wdev, GFP_KERNEL);
361	brcmf_btcoex_restore_part1(btci);
362	btci->vif = NULL;
363}
364
365/**
366 * brcmf_btcoex_attach() - initialize BT coex data
367 * @cfg: driver private cfg80211 data
368 *
369 * return: 0 on success
370 */
371int brcmf_btcoex_attach(struct brcmf_cfg80211_info *cfg)
372{
373	struct brcmf_btcoex_info *btci = NULL;
374	brcmf_dbg(TRACE, "enter\n");
375
376	btci = kmalloc(sizeof(struct brcmf_btcoex_info), GFP_KERNEL);
377	if (!btci)
378		return -ENOMEM;
379
380	btci->bt_state = BRCMF_BT_DHCP_IDLE;
381
382	/* Set up timer for BT  */
383	btci->timer_on = false;
384	btci->timeout = BRCMF_BTCOEX_OPPR_WIN_TIME;
385	init_timer(&btci->timer);
386	btci->timer.data = (ulong)btci;
387	btci->timer.function = brcmf_btcoex_timerfunc;
388	btci->cfg = cfg;
389	btci->saved_regs_part1 = false;
390	btci->saved_regs_part2 = false;
391
392	INIT_WORK(&btci->work, brcmf_btcoex_handler);
393
394	cfg->btcoex = btci;
395	return 0;
396}
397
398/**
399 * brcmf_btcoex_detach - clean BT coex data
400 * @cfg: driver private cfg80211 data
401 */
402void brcmf_btcoex_detach(struct brcmf_cfg80211_info *cfg)
403{
404	brcmf_dbg(TRACE, "enter\n");
405
406	if (!cfg->btcoex)
407		return;
408
409	if (cfg->btcoex->timer_on) {
410		cfg->btcoex->timer_on = false;
411		del_timer_sync(&cfg->btcoex->timer);
412	}
413
414	cancel_work_sync(&cfg->btcoex->work);
415
416	brcmf_btcoex_boost_wifi(cfg->btcoex, false);
417	brcmf_btcoex_restore_part1(cfg->btcoex);
418
419	kfree(cfg->btcoex);
420	cfg->btcoex = NULL;
421}
422
423static void brcmf_btcoex_dhcp_start(struct brcmf_btcoex_info *btci)
424{
425	struct brcmf_if *ifp = btci->vif->ifp;
426
427	btcmf_btcoex_save_part1(btci);
428	/* set new regs values */
429	brcmf_btcoex_params_write(ifp, 66, BRCMF_BT_DHCP_REG66);
430	brcmf_btcoex_params_write(ifp, 41, BRCMF_BT_DHCP_REG41);
431	brcmf_btcoex_params_write(ifp, 68, BRCMF_BT_DHCP_REG68);
432	btci->dhcp_done = false;
433	btci->bt_state = BRCMF_BT_DHCP_START;
434	schedule_work(&btci->work);
435	brcmf_dbg(TRACE, "enable BT DHCP Timer\n");
436}
437
438static void brcmf_btcoex_dhcp_end(struct brcmf_btcoex_info *btci)
439{
440	/* Stop any bt timer because DHCP session is done */
441	btci->dhcp_done = true;
442	if (btci->timer_on) {
443		brcmf_dbg(INFO, "disable BT DHCP Timer\n");
444		btci->timer_on = false;
445		del_timer_sync(&btci->timer);
446
447		/* schedule worker if transition to IDLE is needed */
448		if (btci->bt_state != BRCMF_BT_DHCP_IDLE) {
449			brcmf_dbg(INFO, "bt_state:%d\n",
450				  btci->bt_state);
451			schedule_work(&btci->work);
452		}
453	} else {
454		/* Restore original values */
455		brcmf_btcoex_restore_part1(btci);
456	}
457}
458
459/**
460 * brcmf_btcoex_set_mode - set BT coex mode
461 * @cfg: driver private cfg80211 data
462 * @mode: Wifi-Bluetooth coexistence mode
463 *
464 * return: 0 on success
465 */
466int brcmf_btcoex_set_mode(struct brcmf_cfg80211_vif *vif,
467			  enum brcmf_btcoex_mode mode, u16 duration)
468{
469	struct brcmf_cfg80211_info *cfg = wiphy_priv(vif->wdev.wiphy);
470	struct brcmf_btcoex_info *btci = cfg->btcoex;
471	struct brcmf_if *ifp = cfg->pub->iflist[0];
472
473	switch (mode) {
474	case BRCMF_BTCOEX_DISABLED:
475		brcmf_dbg(INFO, "DHCP session starts\n");
476		if (btci->bt_state != BRCMF_BT_DHCP_IDLE)
477			return -EBUSY;
478		/* Start BT timer only for SCO connection */
479		if (brcmf_btcoex_is_sco_active(ifp)) {
480			btci->timeout = duration;
481			btci->vif = vif;
482			brcmf_btcoex_dhcp_start(btci);
483		}
484		break;
485
486	case BRCMF_BTCOEX_ENABLED:
487		brcmf_dbg(INFO, "DHCP session ends\n");
488		if (btci->bt_state != BRCMF_BT_DHCP_IDLE &&
489		    vif == btci->vif) {
490			brcmf_btcoex_dhcp_end(btci);
491		}
492		break;
493	default:
494		brcmf_dbg(INFO, "Unknown mode, ignored\n");
495	}
496	return 0;
497}
498