Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
// SPDX-License-Identifier: ISC
/*
 * Copyright (c) 2013 Broadcom Corporation
 */
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <net/cfg80211.h>

#include <brcmu_wifi.h>
#include <brcmu_utils.h>
#include <defs.h>
#include "core.h"
#include "debug.h"
#include "fwil.h"
#include "fwil_types.h"
#include "btcoex.h"
#include "p2p.h"
#include "cfg80211.h"

/* T1 start SCO/eSCO priority suppression */
#define BRCMF_BTCOEX_OPPR_WIN_TIME   msecs_to_jiffies(2000)

/* BT registers values during DHCP */
#define BRCMF_BT_DHCP_REG50 0x8022
#define BRCMF_BT_DHCP_REG51 0
#define BRCMF_BT_DHCP_REG64 0
#define BRCMF_BT_DHCP_REG65 0
#define BRCMF_BT_DHCP_REG71 0
#define BRCMF_BT_DHCP_REG66 0x2710
#define BRCMF_BT_DHCP_REG41 0x33
#define BRCMF_BT_DHCP_REG68 0x190

/* number of samples for SCO detection */
#define BRCMF_BT_SCO_SAMPLES 12

/**
* enum brcmf_btcoex_state - BT coex DHCP state machine states
* @BRCMF_BT_DHCP_IDLE: DCHP is idle
* @BRCMF_BT_DHCP_START: DHCP started, wait before
*	boosting wifi priority
* @BRCMF_BT_DHCP_OPPR_WIN: graceful DHCP opportunity ended,
*	boost wifi priority
* @BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT: wifi priority boost end,
*	restore defaults
*/
enum brcmf_btcoex_state {
	BRCMF_BT_DHCP_IDLE,
	BRCMF_BT_DHCP_START,
	BRCMF_BT_DHCP_OPPR_WIN,
	BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT
};

/**
 * struct brcmf_btcoex_info - BT coex related information
 * @vif: interface for which request was done.
 * @timer: timer for DHCP state machine
 * @timeout: configured timeout.
 * @timer_on:  DHCP timer active
 * @dhcp_done: DHCP finished before T1/T2 timer expiration
 * @bt_state: DHCP state machine state
 * @work: DHCP state machine work
 * @cfg: driver private data for cfg80211 interface
 * @reg66: saved value of btc_params 66
 * @reg41: saved value of btc_params 41
 * @reg68: saved value of btc_params 68
 * @saved_regs_part1: flag indicating regs 66,41,68
 *	have been saved
 * @reg51: saved value of btc_params 51
 * @reg64: saved value of btc_params 64
 * @reg65: saved value of btc_params 65
 * @reg71: saved value of btc_params 71
 * @saved_regs_part1: flag indicating regs 50,51,64,65,71
 *	have been saved
 */
struct brcmf_btcoex_info {
	struct brcmf_cfg80211_vif *vif;
	struct timer_list timer;
	u16 timeout;
	bool timer_on;
	bool dhcp_done;
	enum brcmf_btcoex_state bt_state;
	struct work_struct work;
	struct brcmf_cfg80211_info *cfg;
	u32 reg66;
	u32 reg41;
	u32 reg68;
	bool saved_regs_part1;
	u32 reg50;
	u32 reg51;
	u32 reg64;
	u32 reg65;
	u32 reg71;
	bool saved_regs_part2;
};

/**
 * brcmf_btcoex_params_write() - write btc_params firmware variable
 * @ifp: interface
 * @addr: btc_params register number
 * @data: data to write
 */
static s32 brcmf_btcoex_params_write(struct brcmf_if *ifp, u32 addr, u32 data)
{
	struct {
		__le32 addr;
		__le32 data;
	} reg_write;

	reg_write.addr = cpu_to_le32(addr);
	reg_write.data = cpu_to_le32(data);
	return brcmf_fil_iovar_data_set(ifp, "btc_params",
					&reg_write, sizeof(reg_write));
}

/**
 * brcmf_btcoex_params_read() - read btc_params firmware variable
 * @ifp: interface
 * @addr: btc_params register number
 * @data: read data
 */
static s32 brcmf_btcoex_params_read(struct brcmf_if *ifp, u32 addr, u32 *data)
{
	*data = addr;

	return brcmf_fil_iovar_int_get(ifp, "btc_params", data);
}

/**
 * brcmf_btcoex_boost_wifi() - control BT SCO/eSCO parameters
 * @btci: BT coex info
 * @trump_sco:
 *	true - set SCO/eSCO parameters for compatibility
 *		during DHCP window
 *	false - restore saved parameter values
 *
 * Enhanced BT COEX settings for eSCO compatibility during DHCP window
 */
static void brcmf_btcoex_boost_wifi(struct brcmf_btcoex_info *btci,
				    bool trump_sco)
{
	struct brcmf_if *ifp = brcmf_get_ifp(btci->cfg->pub, 0);

	if (trump_sco && !btci->saved_regs_part2) {
		/* this should reduce eSCO agressive
		 * retransmit w/o breaking it
		 */

		/* save current */
		brcmf_dbg(INFO, "new SCO/eSCO coex algo {save & override}\n");
		brcmf_btcoex_params_read(ifp, 50, &btci->reg50);
		brcmf_btcoex_params_read(ifp, 51, &btci->reg51);
		brcmf_btcoex_params_read(ifp, 64, &btci->reg64);
		brcmf_btcoex_params_read(ifp, 65, &btci->reg65);
		brcmf_btcoex_params_read(ifp, 71, &btci->reg71);

		btci->saved_regs_part2 = true;
		brcmf_dbg(INFO,
			  "saved bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
			  btci->reg50, btci->reg51, btci->reg64,
			  btci->reg65, btci->reg71);

		/* pacify the eSco   */
		brcmf_btcoex_params_write(ifp, 50, BRCMF_BT_DHCP_REG50);
		brcmf_btcoex_params_write(ifp, 51, BRCMF_BT_DHCP_REG51);
		brcmf_btcoex_params_write(ifp, 64, BRCMF_BT_DHCP_REG64);
		brcmf_btcoex_params_write(ifp, 65, BRCMF_BT_DHCP_REG65);
		brcmf_btcoex_params_write(ifp, 71, BRCMF_BT_DHCP_REG71);

	} else if (btci->saved_regs_part2) {
		/* restore previously saved bt params */
		brcmf_dbg(INFO, "Do new SCO/eSCO coex algo {restore}\n");
		brcmf_btcoex_params_write(ifp, 50, btci->reg50);
		brcmf_btcoex_params_write(ifp, 51, btci->reg51);
		brcmf_btcoex_params_write(ifp, 64, btci->reg64);
		brcmf_btcoex_params_write(ifp, 65, btci->reg65);
		brcmf_btcoex_params_write(ifp, 71, btci->reg71);

		brcmf_dbg(INFO,
			  "restored bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
			  btci->reg50, btci->reg51, btci->reg64,
			  btci->reg65, btci->reg71);

		btci->saved_regs_part2 = false;
	} else {
		brcmf_dbg(INFO, "attempted to restore not saved BTCOEX params\n");
	}
}

/**
 * brcmf_btcoex_is_sco_active() - check if SCO/eSCO is active
 * @ifp: interface
 *
 * return: true if SCO/eSCO session is active
 */
static bool brcmf_btcoex_is_sco_active(struct brcmf_if *ifp)
{
	int ioc_res = 0;
	bool res = false;
	int sco_id_cnt = 0;
	u32 param27;
	int i;

	for (i = 0; i < BRCMF_BT_SCO_SAMPLES; i++) {
		ioc_res = brcmf_btcoex_params_read(ifp, 27, &param27);

		if (ioc_res < 0) {
			brcmf_err("ioc read btc params error\n");
			break;
		}

		brcmf_dbg(INFO, "sample[%d], btc_params 27:%x\n", i, param27);

		if ((param27 & 0x6) == 2) { /* count both sco & esco  */
			sco_id_cnt++;
		}

		if (sco_id_cnt > 2) {
			brcmf_dbg(INFO,
				  "sco/esco detected, pkt id_cnt:%d samples:%d\n",
				  sco_id_cnt, i);
			res = true;
			break;
		}
	}
	brcmf_dbg(TRACE, "exit: result=%d\n", res);
	return res;
}

/**
 * btcmf_btcoex_save_part1() - save first step parameters.
 */
static void btcmf_btcoex_save_part1(struct brcmf_btcoex_info *btci)
{
	struct brcmf_if *ifp = btci->vif->ifp;

	if (!btci->saved_regs_part1) {
		/* Retrieve and save original reg value */
		brcmf_btcoex_params_read(ifp, 66, &btci->reg66);
		brcmf_btcoex_params_read(ifp, 41, &btci->reg41);
		brcmf_btcoex_params_read(ifp, 68, &btci->reg68);
		btci->saved_regs_part1 = true;
		brcmf_dbg(INFO,
			  "saved btc_params regs (66,41,68) 0x%x 0x%x 0x%x\n",
			  btci->reg66, btci->reg41,
			  btci->reg68);
	}
}

/**
 * brcmf_btcoex_restore_part1() - restore first step parameters.
 */
static void brcmf_btcoex_restore_part1(struct brcmf_btcoex_info *btci)
{
	struct brcmf_if *ifp;

	if (btci->saved_regs_part1) {
		btci->saved_regs_part1 = false;
		ifp = btci->vif->ifp;
		brcmf_btcoex_params_write(ifp, 66, btci->reg66);
		brcmf_btcoex_params_write(ifp, 41, btci->reg41);
		brcmf_btcoex_params_write(ifp, 68, btci->reg68);
		brcmf_dbg(INFO,
			  "restored btc_params regs {66,41,68} 0x%x 0x%x 0x%x\n",
			  btci->reg66, btci->reg41,
			  btci->reg68);
	}
}

/**
 * brcmf_btcoex_timerfunc() - BT coex timer callback
 */
static void brcmf_btcoex_timerfunc(struct timer_list *t)
{
	struct brcmf_btcoex_info *bt_local = from_timer(bt_local, t, timer);
	brcmf_dbg(TRACE, "enter\n");

	bt_local->timer_on = false;
	schedule_work(&bt_local->work);
}

/**
 * brcmf_btcoex_handler() - BT coex state machine work handler
 * @work: work
 */
static void brcmf_btcoex_handler(struct work_struct *work)
{
	struct brcmf_btcoex_info *btci;
	btci = container_of(work, struct brcmf_btcoex_info, work);
	if (btci->timer_on) {
		btci->timer_on = false;
		del_timer_sync(&btci->timer);
	}

	switch (btci->bt_state) {
	case BRCMF_BT_DHCP_START:
		/* DHCP started provide OPPORTUNITY window
		   to get DHCP address
		*/
		brcmf_dbg(INFO, "DHCP started\n");
		btci->bt_state = BRCMF_BT_DHCP_OPPR_WIN;
		if (btci->timeout < BRCMF_BTCOEX_OPPR_WIN_TIME) {
			mod_timer(&btci->timer, btci->timer.expires);
		} else {
			btci->timeout -= BRCMF_BTCOEX_OPPR_WIN_TIME;
			mod_timer(&btci->timer,
				  jiffies + BRCMF_BTCOEX_OPPR_WIN_TIME);
		}
		btci->timer_on = true;
		break;

	case BRCMF_BT_DHCP_OPPR_WIN:
		if (btci->dhcp_done) {
			brcmf_dbg(INFO, "DHCP done before T1 expiration\n");
			goto idle;
		}

		/* DHCP is not over yet, start lowering BT priority */
		brcmf_dbg(INFO, "DHCP T1:%d expired\n",
			  jiffies_to_msecs(BRCMF_BTCOEX_OPPR_WIN_TIME));
		brcmf_btcoex_boost_wifi(btci, true);

		btci->bt_state = BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT;
		mod_timer(&btci->timer, jiffies + btci->timeout);
		btci->timer_on = true;
		break;

	case BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT:
		if (btci->dhcp_done)
			brcmf_dbg(INFO, "DHCP done before T2 expiration\n");
		else
			brcmf_dbg(INFO, "DHCP T2:%d expired\n",
				  BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT);

		goto idle;

	default:
		brcmf_err("invalid state=%d !!!\n", btci->bt_state);
		goto idle;
	}

	return;

idle:
	btci->bt_state = BRCMF_BT_DHCP_IDLE;
	btci->timer_on = false;
	brcmf_btcoex_boost_wifi(btci, false);
	cfg80211_crit_proto_stopped(&btci->vif->wdev, GFP_KERNEL);
	brcmf_btcoex_restore_part1(btci);
	btci->vif = NULL;
}

/**
 * brcmf_btcoex_attach() - initialize BT coex data
 * @cfg: driver private cfg80211 data
 *
 * return: 0 on success
 */
int brcmf_btcoex_attach(struct brcmf_cfg80211_info *cfg)
{
	struct brcmf_btcoex_info *btci = NULL;
	brcmf_dbg(TRACE, "enter\n");

	btci = kmalloc(sizeof(struct brcmf_btcoex_info), GFP_KERNEL);
	if (!btci)
		return -ENOMEM;

	btci->bt_state = BRCMF_BT_DHCP_IDLE;

	/* Set up timer for BT  */
	btci->timer_on = false;
	btci->timeout = BRCMF_BTCOEX_OPPR_WIN_TIME;
	timer_setup(&btci->timer, brcmf_btcoex_timerfunc, 0);
	btci->cfg = cfg;
	btci->saved_regs_part1 = false;
	btci->saved_regs_part2 = false;

	INIT_WORK(&btci->work, brcmf_btcoex_handler);

	cfg->btcoex = btci;
	return 0;
}

/**
 * brcmf_btcoex_detach - clean BT coex data
 * @cfg: driver private cfg80211 data
 */
void brcmf_btcoex_detach(struct brcmf_cfg80211_info *cfg)
{
	brcmf_dbg(TRACE, "enter\n");

	if (!cfg->btcoex)
		return;

	if (cfg->btcoex->timer_on) {
		cfg->btcoex->timer_on = false;
		del_timer_sync(&cfg->btcoex->timer);
	}

	cancel_work_sync(&cfg->btcoex->work);

	brcmf_btcoex_boost_wifi(cfg->btcoex, false);
	brcmf_btcoex_restore_part1(cfg->btcoex);

	kfree(cfg->btcoex);
	cfg->btcoex = NULL;
}

static void brcmf_btcoex_dhcp_start(struct brcmf_btcoex_info *btci)
{
	struct brcmf_if *ifp = btci->vif->ifp;

	btcmf_btcoex_save_part1(btci);
	/* set new regs values */
	brcmf_btcoex_params_write(ifp, 66, BRCMF_BT_DHCP_REG66);
	brcmf_btcoex_params_write(ifp, 41, BRCMF_BT_DHCP_REG41);
	brcmf_btcoex_params_write(ifp, 68, BRCMF_BT_DHCP_REG68);
	btci->dhcp_done = false;
	btci->bt_state = BRCMF_BT_DHCP_START;
	schedule_work(&btci->work);
	brcmf_dbg(TRACE, "enable BT DHCP Timer\n");
}

static void brcmf_btcoex_dhcp_end(struct brcmf_btcoex_info *btci)
{
	/* Stop any bt timer because DHCP session is done */
	btci->dhcp_done = true;
	if (btci->timer_on) {
		brcmf_dbg(INFO, "disable BT DHCP Timer\n");
		btci->timer_on = false;
		del_timer_sync(&btci->timer);

		/* schedule worker if transition to IDLE is needed */
		if (btci->bt_state != BRCMF_BT_DHCP_IDLE) {
			brcmf_dbg(INFO, "bt_state:%d\n",
				  btci->bt_state);
			schedule_work(&btci->work);
		}
	} else {
		/* Restore original values */
		brcmf_btcoex_restore_part1(btci);
	}
}

/**
 * brcmf_btcoex_set_mode - set BT coex mode
 * @cfg: driver private cfg80211 data
 * @mode: Wifi-Bluetooth coexistence mode
 *
 * return: 0 on success
 */
int brcmf_btcoex_set_mode(struct brcmf_cfg80211_vif *vif,
			  enum brcmf_btcoex_mode mode, u16 duration)
{
	struct brcmf_cfg80211_info *cfg = wiphy_to_cfg(vif->wdev.wiphy);
	struct brcmf_btcoex_info *btci = cfg->btcoex;
	struct brcmf_if *ifp = brcmf_get_ifp(cfg->pub, 0);

	switch (mode) {
	case BRCMF_BTCOEX_DISABLED:
		brcmf_dbg(INFO, "DHCP session starts\n");
		if (btci->bt_state != BRCMF_BT_DHCP_IDLE)
			return -EBUSY;
		/* Start BT timer only for SCO connection */
		if (brcmf_btcoex_is_sco_active(ifp)) {
			btci->timeout = msecs_to_jiffies(duration);
			btci->vif = vif;
			brcmf_btcoex_dhcp_start(btci);
		}
		break;

	case BRCMF_BTCOEX_ENABLED:
		brcmf_dbg(INFO, "DHCP session ends\n");
		if (btci->bt_state != BRCMF_BT_DHCP_IDLE &&
		    vif == btci->vif) {
			brcmf_btcoex_dhcp_end(btci);
		}
		break;
	default:
		brcmf_dbg(INFO, "Unknown mode, ignored\n");
	}
	return 0;
}