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1 /*
2  *  Bluetooth Software UART Qualcomm protocol
3  *
4  *  HCI_IBS (HCI In-Band Sleep) is Qualcomm's power management
5  *  protocol extension to H4.
6  *
7  *  Copyright (C) 2007 Texas Instruments, Inc.
8  *  Copyright (c) 2010, 2012 The Linux Foundation. All rights reserved.
9  *
10  *  Acknowledgements:
11  *  This file is based on hci_ll.c, which was...
12  *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
13  *  which was in turn based on hci_h4.c, which was written
14  *  by Maxim Krasnyansky and Marcel Holtmann.
15  *
16  *  This program is free software; you can redistribute it and/or modify
17  *  it under the terms of the GNU General Public License version 2
18  *  as published by the Free Software Foundation
19  *
20  *  This program is distributed in the hope that it will be useful,
21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  *  GNU General Public License for more details.
24  *
25  *  You should have received a copy of the GNU General Public License
26  *  along with this program; if not, write to the Free Software
27  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
28  *
29  */
30 
31 #include <linux/kernel.h>
32 #include <linux/debugfs.h>
33 
34 #include <net/bluetooth/bluetooth.h>
35 #include <net/bluetooth/hci_core.h>
36 
37 #include "hci_uart.h"
38 #include "btqca.h"
39 
40 /* HCI_IBS protocol messages */
41 #define HCI_IBS_SLEEP_IND	0xFE
42 #define HCI_IBS_WAKE_IND	0xFD
43 #define HCI_IBS_WAKE_ACK	0xFC
44 #define HCI_MAX_IBS_SIZE	10
45 
46 /* Controller states */
47 #define STATE_IN_BAND_SLEEP_ENABLED	1
48 
49 #define IBS_WAKE_RETRANS_TIMEOUT_MS	100
50 #define IBS_TX_IDLE_TIMEOUT_MS		2000
51 #define BAUDRATE_SETTLE_TIMEOUT_MS	300
52 
53 /* HCI_IBS transmit side sleep protocol states */
54 enum tx_ibs_states {
55 	HCI_IBS_TX_ASLEEP,
56 	HCI_IBS_TX_WAKING,
57 	HCI_IBS_TX_AWAKE,
58 };
59 
60 /* HCI_IBS receive side sleep protocol states */
61 enum rx_states {
62 	HCI_IBS_RX_ASLEEP,
63 	HCI_IBS_RX_AWAKE,
64 };
65 
66 /* HCI_IBS transmit and receive side clock state vote */
67 enum hci_ibs_clock_state_vote {
68 	HCI_IBS_VOTE_STATS_UPDATE,
69 	HCI_IBS_TX_VOTE_CLOCK_ON,
70 	HCI_IBS_TX_VOTE_CLOCK_OFF,
71 	HCI_IBS_RX_VOTE_CLOCK_ON,
72 	HCI_IBS_RX_VOTE_CLOCK_OFF,
73 };
74 
75 struct qca_data {
76 	struct hci_uart *hu;
77 	struct sk_buff *rx_skb;
78 	struct sk_buff_head txq;
79 	struct sk_buff_head tx_wait_q;	/* HCI_IBS wait queue	*/
80 	spinlock_t hci_ibs_lock;	/* HCI_IBS state lock	*/
81 	u8 tx_ibs_state;	/* HCI_IBS transmit side power state*/
82 	u8 rx_ibs_state;	/* HCI_IBS receive side power state */
83 	bool tx_vote;		/* Clock must be on for TX */
84 	bool rx_vote;		/* Clock must be on for RX */
85 	struct timer_list tx_idle_timer;
86 	u32 tx_idle_delay;
87 	struct timer_list wake_retrans_timer;
88 	u32 wake_retrans;
89 	struct workqueue_struct *workqueue;
90 	struct work_struct ws_awake_rx;
91 	struct work_struct ws_awake_device;
92 	struct work_struct ws_rx_vote_off;
93 	struct work_struct ws_tx_vote_off;
94 	unsigned long flags;
95 
96 	/* For debugging purpose */
97 	u64 ibs_sent_wacks;
98 	u64 ibs_sent_slps;
99 	u64 ibs_sent_wakes;
100 	u64 ibs_recv_wacks;
101 	u64 ibs_recv_slps;
102 	u64 ibs_recv_wakes;
103 	u64 vote_last_jif;
104 	u32 vote_on_ms;
105 	u32 vote_off_ms;
106 	u64 tx_votes_on;
107 	u64 rx_votes_on;
108 	u64 tx_votes_off;
109 	u64 rx_votes_off;
110 	u64 votes_on;
111 	u64 votes_off;
112 };
113 
__serial_clock_on(struct tty_struct * tty)114 static void __serial_clock_on(struct tty_struct *tty)
115 {
116 	/* TODO: Some chipset requires to enable UART clock on client
117 	 * side to save power consumption or manual work is required.
118 	 * Please put your code to control UART clock here if needed
119 	 */
120 }
121 
__serial_clock_off(struct tty_struct * tty)122 static void __serial_clock_off(struct tty_struct *tty)
123 {
124 	/* TODO: Some chipset requires to disable UART clock on client
125 	 * side to save power consumption or manual work is required.
126 	 * Please put your code to control UART clock off here if needed
127 	 */
128 }
129 
130 /* serial_clock_vote needs to be called with the ibs lock held */
serial_clock_vote(unsigned long vote,struct hci_uart * hu)131 static void serial_clock_vote(unsigned long vote, struct hci_uart *hu)
132 {
133 	struct qca_data *qca = hu->priv;
134 	unsigned int diff;
135 
136 	bool old_vote = (qca->tx_vote | qca->rx_vote);
137 	bool new_vote;
138 
139 	switch (vote) {
140 	case HCI_IBS_VOTE_STATS_UPDATE:
141 		diff = jiffies_to_msecs(jiffies - qca->vote_last_jif);
142 
143 		if (old_vote)
144 			qca->vote_off_ms += diff;
145 		else
146 			qca->vote_on_ms += diff;
147 		return;
148 
149 	case HCI_IBS_TX_VOTE_CLOCK_ON:
150 		qca->tx_vote = true;
151 		qca->tx_votes_on++;
152 		new_vote = true;
153 		break;
154 
155 	case HCI_IBS_RX_VOTE_CLOCK_ON:
156 		qca->rx_vote = true;
157 		qca->rx_votes_on++;
158 		new_vote = true;
159 		break;
160 
161 	case HCI_IBS_TX_VOTE_CLOCK_OFF:
162 		qca->tx_vote = false;
163 		qca->tx_votes_off++;
164 		new_vote = qca->rx_vote | qca->tx_vote;
165 		break;
166 
167 	case HCI_IBS_RX_VOTE_CLOCK_OFF:
168 		qca->rx_vote = false;
169 		qca->rx_votes_off++;
170 		new_vote = qca->rx_vote | qca->tx_vote;
171 		break;
172 
173 	default:
174 		BT_ERR("Voting irregularity");
175 		return;
176 	}
177 
178 	if (new_vote != old_vote) {
179 		if (new_vote)
180 			__serial_clock_on(hu->tty);
181 		else
182 			__serial_clock_off(hu->tty);
183 
184 		BT_DBG("Vote serial clock %s(%s)", new_vote ? "true" : "false",
185 		       vote ? "true" : "false");
186 
187 		diff = jiffies_to_msecs(jiffies - qca->vote_last_jif);
188 
189 		if (new_vote) {
190 			qca->votes_on++;
191 			qca->vote_off_ms += diff;
192 		} else {
193 			qca->votes_off++;
194 			qca->vote_on_ms += diff;
195 		}
196 		qca->vote_last_jif = jiffies;
197 	}
198 }
199 
200 /* Builds and sends an HCI_IBS command packet.
201  * These are very simple packets with only 1 cmd byte.
202  */
send_hci_ibs_cmd(u8 cmd,struct hci_uart * hu)203 static int send_hci_ibs_cmd(u8 cmd, struct hci_uart *hu)
204 {
205 	int err = 0;
206 	struct sk_buff *skb = NULL;
207 	struct qca_data *qca = hu->priv;
208 
209 	BT_DBG("hu %p send hci ibs cmd 0x%x", hu, cmd);
210 
211 	skb = bt_skb_alloc(1, GFP_ATOMIC);
212 	if (!skb) {
213 		BT_ERR("Failed to allocate memory for HCI_IBS packet");
214 		return -ENOMEM;
215 	}
216 
217 	/* Assign HCI_IBS type */
218 	*skb_put(skb, 1) = cmd;
219 
220 	skb_queue_tail(&qca->txq, skb);
221 
222 	return err;
223 }
224 
qca_wq_awake_device(struct work_struct * work)225 static void qca_wq_awake_device(struct work_struct *work)
226 {
227 	struct qca_data *qca = container_of(work, struct qca_data,
228 					    ws_awake_device);
229 	struct hci_uart *hu = qca->hu;
230 	unsigned long retrans_delay;
231 
232 	BT_DBG("hu %p wq awake device", hu);
233 
234 	/* Vote for serial clock */
235 	serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_ON, hu);
236 
237 	spin_lock(&qca->hci_ibs_lock);
238 
239 	/* Send wake indication to device */
240 	if (send_hci_ibs_cmd(HCI_IBS_WAKE_IND, hu) < 0)
241 		BT_ERR("Failed to send WAKE to device");
242 
243 	qca->ibs_sent_wakes++;
244 
245 	/* Start retransmit timer */
246 	retrans_delay = msecs_to_jiffies(qca->wake_retrans);
247 	mod_timer(&qca->wake_retrans_timer, jiffies + retrans_delay);
248 
249 	spin_unlock(&qca->hci_ibs_lock);
250 
251 	/* Actually send the packets */
252 	hci_uart_tx_wakeup(hu);
253 }
254 
qca_wq_awake_rx(struct work_struct * work)255 static void qca_wq_awake_rx(struct work_struct *work)
256 {
257 	struct qca_data *qca = container_of(work, struct qca_data,
258 					    ws_awake_rx);
259 	struct hci_uart *hu = qca->hu;
260 
261 	BT_DBG("hu %p wq awake rx", hu);
262 
263 	serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_ON, hu);
264 
265 	spin_lock(&qca->hci_ibs_lock);
266 	qca->rx_ibs_state = HCI_IBS_RX_AWAKE;
267 
268 	/* Always acknowledge device wake up,
269 	 * sending IBS message doesn't count as TX ON.
270 	 */
271 	if (send_hci_ibs_cmd(HCI_IBS_WAKE_ACK, hu) < 0)
272 		BT_ERR("Failed to acknowledge device wake up");
273 
274 	qca->ibs_sent_wacks++;
275 
276 	spin_unlock(&qca->hci_ibs_lock);
277 
278 	/* Actually send the packets */
279 	hci_uart_tx_wakeup(hu);
280 }
281 
qca_wq_serial_rx_clock_vote_off(struct work_struct * work)282 static void qca_wq_serial_rx_clock_vote_off(struct work_struct *work)
283 {
284 	struct qca_data *qca = container_of(work, struct qca_data,
285 					    ws_rx_vote_off);
286 	struct hci_uart *hu = qca->hu;
287 
288 	BT_DBG("hu %p rx clock vote off", hu);
289 
290 	serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_OFF, hu);
291 }
292 
qca_wq_serial_tx_clock_vote_off(struct work_struct * work)293 static void qca_wq_serial_tx_clock_vote_off(struct work_struct *work)
294 {
295 	struct qca_data *qca = container_of(work, struct qca_data,
296 					    ws_tx_vote_off);
297 	struct hci_uart *hu = qca->hu;
298 
299 	BT_DBG("hu %p tx clock vote off", hu);
300 
301 	/* Run HCI tx handling unlocked */
302 	hci_uart_tx_wakeup(hu);
303 
304 	/* Now that message queued to tty driver, vote for tty clocks off.
305 	 * It is up to the tty driver to pend the clocks off until tx done.
306 	 */
307 	serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_OFF, hu);
308 }
309 
hci_ibs_tx_idle_timeout(unsigned long arg)310 static void hci_ibs_tx_idle_timeout(unsigned long arg)
311 {
312 	struct hci_uart *hu = (struct hci_uart *)arg;
313 	struct qca_data *qca = hu->priv;
314 	unsigned long flags;
315 
316 	BT_DBG("hu %p idle timeout in %d state", hu, qca->tx_ibs_state);
317 
318 	spin_lock_irqsave_nested(&qca->hci_ibs_lock,
319 				 flags, SINGLE_DEPTH_NESTING);
320 
321 	switch (qca->tx_ibs_state) {
322 	case HCI_IBS_TX_AWAKE:
323 		/* TX_IDLE, go to SLEEP */
324 		if (send_hci_ibs_cmd(HCI_IBS_SLEEP_IND, hu) < 0) {
325 			BT_ERR("Failed to send SLEEP to device");
326 			break;
327 		}
328 		qca->tx_ibs_state = HCI_IBS_TX_ASLEEP;
329 		qca->ibs_sent_slps++;
330 		queue_work(qca->workqueue, &qca->ws_tx_vote_off);
331 		break;
332 
333 	case HCI_IBS_TX_ASLEEP:
334 	case HCI_IBS_TX_WAKING:
335 		/* Fall through */
336 
337 	default:
338 		BT_ERR("Spurrious timeout tx state %d", qca->tx_ibs_state);
339 		break;
340 	}
341 
342 	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
343 }
344 
hci_ibs_wake_retrans_timeout(unsigned long arg)345 static void hci_ibs_wake_retrans_timeout(unsigned long arg)
346 {
347 	struct hci_uart *hu = (struct hci_uart *)arg;
348 	struct qca_data *qca = hu->priv;
349 	unsigned long flags, retrans_delay;
350 	bool retransmit = false;
351 
352 	BT_DBG("hu %p wake retransmit timeout in %d state",
353 		hu, qca->tx_ibs_state);
354 
355 	spin_lock_irqsave_nested(&qca->hci_ibs_lock,
356 				 flags, SINGLE_DEPTH_NESTING);
357 
358 	switch (qca->tx_ibs_state) {
359 	case HCI_IBS_TX_WAKING:
360 		/* No WAKE_ACK, retransmit WAKE */
361 		retransmit = true;
362 		if (send_hci_ibs_cmd(HCI_IBS_WAKE_IND, hu) < 0) {
363 			BT_ERR("Failed to acknowledge device wake up");
364 			break;
365 		}
366 		qca->ibs_sent_wakes++;
367 		retrans_delay = msecs_to_jiffies(qca->wake_retrans);
368 		mod_timer(&qca->wake_retrans_timer, jiffies + retrans_delay);
369 		break;
370 
371 	case HCI_IBS_TX_ASLEEP:
372 	case HCI_IBS_TX_AWAKE:
373 		/* Fall through */
374 
375 	default:
376 		BT_ERR("Spurrious timeout tx state %d", qca->tx_ibs_state);
377 		break;
378 	}
379 
380 	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
381 
382 	if (retransmit)
383 		hci_uart_tx_wakeup(hu);
384 }
385 
386 /* Initialize protocol */
qca_open(struct hci_uart * hu)387 static int qca_open(struct hci_uart *hu)
388 {
389 	struct qca_data *qca;
390 
391 	BT_DBG("hu %p qca_open", hu);
392 
393 	qca = kzalloc(sizeof(struct qca_data), GFP_ATOMIC);
394 	if (!qca)
395 		return -ENOMEM;
396 
397 	skb_queue_head_init(&qca->txq);
398 	skb_queue_head_init(&qca->tx_wait_q);
399 	spin_lock_init(&qca->hci_ibs_lock);
400 	qca->workqueue = create_singlethread_workqueue("qca_wq");
401 	if (!qca->workqueue) {
402 		BT_ERR("QCA Workqueue not initialized properly");
403 		kfree(qca);
404 		return -ENOMEM;
405 	}
406 
407 	INIT_WORK(&qca->ws_awake_rx, qca_wq_awake_rx);
408 	INIT_WORK(&qca->ws_awake_device, qca_wq_awake_device);
409 	INIT_WORK(&qca->ws_rx_vote_off, qca_wq_serial_rx_clock_vote_off);
410 	INIT_WORK(&qca->ws_tx_vote_off, qca_wq_serial_tx_clock_vote_off);
411 
412 	qca->hu = hu;
413 
414 	/* Assume we start with both sides asleep -- extra wakes OK */
415 	qca->tx_ibs_state = HCI_IBS_TX_ASLEEP;
416 	qca->rx_ibs_state = HCI_IBS_RX_ASLEEP;
417 
418 	/* clocks actually on, but we start votes off */
419 	qca->tx_vote = false;
420 	qca->rx_vote = false;
421 	qca->flags = 0;
422 
423 	qca->ibs_sent_wacks = 0;
424 	qca->ibs_sent_slps = 0;
425 	qca->ibs_sent_wakes = 0;
426 	qca->ibs_recv_wacks = 0;
427 	qca->ibs_recv_slps = 0;
428 	qca->ibs_recv_wakes = 0;
429 	qca->vote_last_jif = jiffies;
430 	qca->vote_on_ms = 0;
431 	qca->vote_off_ms = 0;
432 	qca->votes_on = 0;
433 	qca->votes_off = 0;
434 	qca->tx_votes_on = 0;
435 	qca->tx_votes_off = 0;
436 	qca->rx_votes_on = 0;
437 	qca->rx_votes_off = 0;
438 
439 	hu->priv = qca;
440 
441 	init_timer(&qca->wake_retrans_timer);
442 	qca->wake_retrans_timer.function = hci_ibs_wake_retrans_timeout;
443 	qca->wake_retrans_timer.data = (u_long)hu;
444 	qca->wake_retrans = IBS_WAKE_RETRANS_TIMEOUT_MS;
445 
446 	init_timer(&qca->tx_idle_timer);
447 	qca->tx_idle_timer.function = hci_ibs_tx_idle_timeout;
448 	qca->tx_idle_timer.data = (u_long)hu;
449 	qca->tx_idle_delay = IBS_TX_IDLE_TIMEOUT_MS;
450 
451 	BT_DBG("HCI_UART_QCA open, tx_idle_delay=%u, wake_retrans=%u",
452 	       qca->tx_idle_delay, qca->wake_retrans);
453 
454 	return 0;
455 }
456 
qca_debugfs_init(struct hci_dev * hdev)457 static void qca_debugfs_init(struct hci_dev *hdev)
458 {
459 	struct hci_uart *hu = hci_get_drvdata(hdev);
460 	struct qca_data *qca = hu->priv;
461 	struct dentry *ibs_dir;
462 	umode_t mode;
463 
464 	if (!hdev->debugfs)
465 		return;
466 
467 	ibs_dir = debugfs_create_dir("ibs", hdev->debugfs);
468 
469 	/* read only */
470 	mode = S_IRUGO;
471 	debugfs_create_u8("tx_ibs_state", mode, ibs_dir, &qca->tx_ibs_state);
472 	debugfs_create_u8("rx_ibs_state", mode, ibs_dir, &qca->rx_ibs_state);
473 	debugfs_create_u64("ibs_sent_sleeps", mode, ibs_dir,
474 			   &qca->ibs_sent_slps);
475 	debugfs_create_u64("ibs_sent_wakes", mode, ibs_dir,
476 			   &qca->ibs_sent_wakes);
477 	debugfs_create_u64("ibs_sent_wake_acks", mode, ibs_dir,
478 			   &qca->ibs_sent_wacks);
479 	debugfs_create_u64("ibs_recv_sleeps", mode, ibs_dir,
480 			   &qca->ibs_recv_slps);
481 	debugfs_create_u64("ibs_recv_wakes", mode, ibs_dir,
482 			   &qca->ibs_recv_wakes);
483 	debugfs_create_u64("ibs_recv_wake_acks", mode, ibs_dir,
484 			   &qca->ibs_recv_wacks);
485 	debugfs_create_bool("tx_vote", mode, ibs_dir, &qca->tx_vote);
486 	debugfs_create_u64("tx_votes_on", mode, ibs_dir, &qca->tx_votes_on);
487 	debugfs_create_u64("tx_votes_off", mode, ibs_dir, &qca->tx_votes_off);
488 	debugfs_create_bool("rx_vote", mode, ibs_dir, &qca->rx_vote);
489 	debugfs_create_u64("rx_votes_on", mode, ibs_dir, &qca->rx_votes_on);
490 	debugfs_create_u64("rx_votes_off", mode, ibs_dir, &qca->rx_votes_off);
491 	debugfs_create_u64("votes_on", mode, ibs_dir, &qca->votes_on);
492 	debugfs_create_u64("votes_off", mode, ibs_dir, &qca->votes_off);
493 	debugfs_create_u32("vote_on_ms", mode, ibs_dir, &qca->vote_on_ms);
494 	debugfs_create_u32("vote_off_ms", mode, ibs_dir, &qca->vote_off_ms);
495 
496 	/* read/write */
497 	mode = S_IRUGO | S_IWUSR;
498 	debugfs_create_u32("wake_retrans", mode, ibs_dir, &qca->wake_retrans);
499 	debugfs_create_u32("tx_idle_delay", mode, ibs_dir,
500 			   &qca->tx_idle_delay);
501 }
502 
503 /* Flush protocol data */
qca_flush(struct hci_uart * hu)504 static int qca_flush(struct hci_uart *hu)
505 {
506 	struct qca_data *qca = hu->priv;
507 
508 	BT_DBG("hu %p qca flush", hu);
509 
510 	skb_queue_purge(&qca->tx_wait_q);
511 	skb_queue_purge(&qca->txq);
512 
513 	return 0;
514 }
515 
516 /* Close protocol */
qca_close(struct hci_uart * hu)517 static int qca_close(struct hci_uart *hu)
518 {
519 	struct qca_data *qca = hu->priv;
520 
521 	BT_DBG("hu %p qca close", hu);
522 
523 	serial_clock_vote(HCI_IBS_VOTE_STATS_UPDATE, hu);
524 
525 	skb_queue_purge(&qca->tx_wait_q);
526 	skb_queue_purge(&qca->txq);
527 	del_timer(&qca->tx_idle_timer);
528 	del_timer(&qca->wake_retrans_timer);
529 	destroy_workqueue(qca->workqueue);
530 	qca->hu = NULL;
531 
532 	kfree_skb(qca->rx_skb);
533 
534 	hu->priv = NULL;
535 
536 	kfree(qca);
537 
538 	return 0;
539 }
540 
541 /* Called upon a wake-up-indication from the device.
542  */
device_want_to_wakeup(struct hci_uart * hu)543 static void device_want_to_wakeup(struct hci_uart *hu)
544 {
545 	unsigned long flags;
546 	struct qca_data *qca = hu->priv;
547 
548 	BT_DBG("hu %p want to wake up", hu);
549 
550 	spin_lock_irqsave(&qca->hci_ibs_lock, flags);
551 
552 	qca->ibs_recv_wakes++;
553 
554 	switch (qca->rx_ibs_state) {
555 	case HCI_IBS_RX_ASLEEP:
556 		/* Make sure clock is on - we may have turned clock off since
557 		 * receiving the wake up indicator awake rx clock.
558 		 */
559 		queue_work(qca->workqueue, &qca->ws_awake_rx);
560 		spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
561 		return;
562 
563 	case HCI_IBS_RX_AWAKE:
564 		/* Always acknowledge device wake up,
565 		 * sending IBS message doesn't count as TX ON.
566 		 */
567 		if (send_hci_ibs_cmd(HCI_IBS_WAKE_ACK, hu) < 0) {
568 			BT_ERR("Failed to acknowledge device wake up");
569 			break;
570 		}
571 		qca->ibs_sent_wacks++;
572 		break;
573 
574 	default:
575 		/* Any other state is illegal */
576 		BT_ERR("Received HCI_IBS_WAKE_IND in rx state %d",
577 		       qca->rx_ibs_state);
578 		break;
579 	}
580 
581 	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
582 
583 	/* Actually send the packets */
584 	hci_uart_tx_wakeup(hu);
585 }
586 
587 /* Called upon a sleep-indication from the device.
588  */
device_want_to_sleep(struct hci_uart * hu)589 static void device_want_to_sleep(struct hci_uart *hu)
590 {
591 	unsigned long flags;
592 	struct qca_data *qca = hu->priv;
593 
594 	BT_DBG("hu %p want to sleep", hu);
595 
596 	spin_lock_irqsave(&qca->hci_ibs_lock, flags);
597 
598 	qca->ibs_recv_slps++;
599 
600 	switch (qca->rx_ibs_state) {
601 	case HCI_IBS_RX_AWAKE:
602 		/* Update state */
603 		qca->rx_ibs_state = HCI_IBS_RX_ASLEEP;
604 		/* Vote off rx clock under workqueue */
605 		queue_work(qca->workqueue, &qca->ws_rx_vote_off);
606 		break;
607 
608 	case HCI_IBS_RX_ASLEEP:
609 		/* Fall through */
610 
611 	default:
612 		/* Any other state is illegal */
613 		BT_ERR("Received HCI_IBS_SLEEP_IND in rx state %d",
614 		       qca->rx_ibs_state);
615 		break;
616 	}
617 
618 	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
619 }
620 
621 /* Called upon wake-up-acknowledgement from the device
622  */
device_woke_up(struct hci_uart * hu)623 static void device_woke_up(struct hci_uart *hu)
624 {
625 	unsigned long flags, idle_delay;
626 	struct qca_data *qca = hu->priv;
627 	struct sk_buff *skb = NULL;
628 
629 	BT_DBG("hu %p woke up", hu);
630 
631 	spin_lock_irqsave(&qca->hci_ibs_lock, flags);
632 
633 	qca->ibs_recv_wacks++;
634 
635 	switch (qca->tx_ibs_state) {
636 	case HCI_IBS_TX_AWAKE:
637 		/* Expect one if we send 2 WAKEs */
638 		BT_DBG("Received HCI_IBS_WAKE_ACK in tx state %d",
639 		       qca->tx_ibs_state);
640 		break;
641 
642 	case HCI_IBS_TX_WAKING:
643 		/* Send pending packets */
644 		while ((skb = skb_dequeue(&qca->tx_wait_q)))
645 			skb_queue_tail(&qca->txq, skb);
646 
647 		/* Switch timers and change state to HCI_IBS_TX_AWAKE */
648 		del_timer(&qca->wake_retrans_timer);
649 		idle_delay = msecs_to_jiffies(qca->tx_idle_delay);
650 		mod_timer(&qca->tx_idle_timer, jiffies + idle_delay);
651 		qca->tx_ibs_state = HCI_IBS_TX_AWAKE;
652 		break;
653 
654 	case HCI_IBS_TX_ASLEEP:
655 		/* Fall through */
656 
657 	default:
658 		BT_ERR("Received HCI_IBS_WAKE_ACK in tx state %d",
659 		       qca->tx_ibs_state);
660 		break;
661 	}
662 
663 	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
664 
665 	/* Actually send the packets */
666 	hci_uart_tx_wakeup(hu);
667 }
668 
669 /* Enqueue frame for transmittion (padding, crc, etc) may be called from
670  * two simultaneous tasklets.
671  */
qca_enqueue(struct hci_uart * hu,struct sk_buff * skb)672 static int qca_enqueue(struct hci_uart *hu, struct sk_buff *skb)
673 {
674 	unsigned long flags = 0, idle_delay;
675 	struct qca_data *qca = hu->priv;
676 
677 	BT_DBG("hu %p qca enq skb %p tx_ibs_state %d", hu, skb,
678 	       qca->tx_ibs_state);
679 
680 	/* Prepend skb with frame type */
681 	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
682 
683 	/* Don't go to sleep in middle of patch download or
684 	 * Out-Of-Band(GPIOs control) sleep is selected.
685 	 */
686 	if (!test_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags)) {
687 		skb_queue_tail(&qca->txq, skb);
688 		return 0;
689 	}
690 
691 	spin_lock_irqsave(&qca->hci_ibs_lock, flags);
692 
693 	/* Act according to current state */
694 	switch (qca->tx_ibs_state) {
695 	case HCI_IBS_TX_AWAKE:
696 		BT_DBG("Device awake, sending normally");
697 		skb_queue_tail(&qca->txq, skb);
698 		idle_delay = msecs_to_jiffies(qca->tx_idle_delay);
699 		mod_timer(&qca->tx_idle_timer, jiffies + idle_delay);
700 		break;
701 
702 	case HCI_IBS_TX_ASLEEP:
703 		BT_DBG("Device asleep, waking up and queueing packet");
704 		/* Save packet for later */
705 		skb_queue_tail(&qca->tx_wait_q, skb);
706 
707 		qca->tx_ibs_state = HCI_IBS_TX_WAKING;
708 		/* Schedule a work queue to wake up device */
709 		queue_work(qca->workqueue, &qca->ws_awake_device);
710 		break;
711 
712 	case HCI_IBS_TX_WAKING:
713 		BT_DBG("Device waking up, queueing packet");
714 		/* Transient state; just keep packet for later */
715 		skb_queue_tail(&qca->tx_wait_q, skb);
716 		break;
717 
718 	default:
719 		BT_ERR("Illegal tx state: %d (losing packet)",
720 		       qca->tx_ibs_state);
721 		kfree_skb(skb);
722 		break;
723 	}
724 
725 	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
726 
727 	return 0;
728 }
729 
qca_ibs_sleep_ind(struct hci_dev * hdev,struct sk_buff * skb)730 static int qca_ibs_sleep_ind(struct hci_dev *hdev, struct sk_buff *skb)
731 {
732 	struct hci_uart *hu = hci_get_drvdata(hdev);
733 
734 	BT_DBG("hu %p recv hci ibs cmd 0x%x", hu, HCI_IBS_SLEEP_IND);
735 
736 	device_want_to_sleep(hu);
737 
738 	kfree_skb(skb);
739 	return 0;
740 }
741 
qca_ibs_wake_ind(struct hci_dev * hdev,struct sk_buff * skb)742 static int qca_ibs_wake_ind(struct hci_dev *hdev, struct sk_buff *skb)
743 {
744 	struct hci_uart *hu = hci_get_drvdata(hdev);
745 
746 	BT_DBG("hu %p recv hci ibs cmd 0x%x", hu, HCI_IBS_WAKE_IND);
747 
748 	device_want_to_wakeup(hu);
749 
750 	kfree_skb(skb);
751 	return 0;
752 }
753 
qca_ibs_wake_ack(struct hci_dev * hdev,struct sk_buff * skb)754 static int qca_ibs_wake_ack(struct hci_dev *hdev, struct sk_buff *skb)
755 {
756 	struct hci_uart *hu = hci_get_drvdata(hdev);
757 
758 	BT_DBG("hu %p recv hci ibs cmd 0x%x", hu, HCI_IBS_WAKE_ACK);
759 
760 	device_woke_up(hu);
761 
762 	kfree_skb(skb);
763 	return 0;
764 }
765 
766 #define QCA_IBS_SLEEP_IND_EVENT \
767 	.type = HCI_IBS_SLEEP_IND, \
768 	.hlen = 0, \
769 	.loff = 0, \
770 	.lsize = 0, \
771 	.maxlen = HCI_MAX_IBS_SIZE
772 
773 #define QCA_IBS_WAKE_IND_EVENT \
774 	.type = HCI_IBS_WAKE_IND, \
775 	.hlen = 0, \
776 	.loff = 0, \
777 	.lsize = 0, \
778 	.maxlen = HCI_MAX_IBS_SIZE
779 
780 #define QCA_IBS_WAKE_ACK_EVENT \
781 	.type = HCI_IBS_WAKE_ACK, \
782 	.hlen = 0, \
783 	.loff = 0, \
784 	.lsize = 0, \
785 	.maxlen = HCI_MAX_IBS_SIZE
786 
787 static const struct h4_recv_pkt qca_recv_pkts[] = {
788 	{ H4_RECV_ACL,             .recv = hci_recv_frame    },
789 	{ H4_RECV_SCO,             .recv = hci_recv_frame    },
790 	{ H4_RECV_EVENT,           .recv = hci_recv_frame    },
791 	{ QCA_IBS_WAKE_IND_EVENT,  .recv = qca_ibs_wake_ind  },
792 	{ QCA_IBS_WAKE_ACK_EVENT,  .recv = qca_ibs_wake_ack  },
793 	{ QCA_IBS_SLEEP_IND_EVENT, .recv = qca_ibs_sleep_ind },
794 };
795 
qca_recv(struct hci_uart * hu,const void * data,int count)796 static int qca_recv(struct hci_uart *hu, const void *data, int count)
797 {
798 	struct qca_data *qca = hu->priv;
799 
800 	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
801 		return -EUNATCH;
802 
803 	qca->rx_skb = h4_recv_buf(hu->hdev, qca->rx_skb, data, count,
804 				  qca_recv_pkts, ARRAY_SIZE(qca_recv_pkts));
805 	if (IS_ERR(qca->rx_skb)) {
806 		int err = PTR_ERR(qca->rx_skb);
807 		BT_ERR("%s: Frame reassembly failed (%d)", hu->hdev->name, err);
808 		qca->rx_skb = NULL;
809 		return err;
810 	}
811 
812 	return count;
813 }
814 
qca_dequeue(struct hci_uart * hu)815 static struct sk_buff *qca_dequeue(struct hci_uart *hu)
816 {
817 	struct qca_data *qca = hu->priv;
818 
819 	return skb_dequeue(&qca->txq);
820 }
821 
qca_get_baudrate_value(int speed)822 static uint8_t qca_get_baudrate_value(int speed)
823 {
824 	switch (speed) {
825 	case 9600:
826 		return QCA_BAUDRATE_9600;
827 	case 19200:
828 		return QCA_BAUDRATE_19200;
829 	case 38400:
830 		return QCA_BAUDRATE_38400;
831 	case 57600:
832 		return QCA_BAUDRATE_57600;
833 	case 115200:
834 		return QCA_BAUDRATE_115200;
835 	case 230400:
836 		return QCA_BAUDRATE_230400;
837 	case 460800:
838 		return QCA_BAUDRATE_460800;
839 	case 500000:
840 		return QCA_BAUDRATE_500000;
841 	case 921600:
842 		return QCA_BAUDRATE_921600;
843 	case 1000000:
844 		return QCA_BAUDRATE_1000000;
845 	case 2000000:
846 		return QCA_BAUDRATE_2000000;
847 	case 3000000:
848 		return QCA_BAUDRATE_3000000;
849 	case 3500000:
850 		return QCA_BAUDRATE_3500000;
851 	default:
852 		return QCA_BAUDRATE_115200;
853 	}
854 }
855 
qca_set_baudrate(struct hci_dev * hdev,uint8_t baudrate)856 static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
857 {
858 	struct hci_uart *hu = hci_get_drvdata(hdev);
859 	struct qca_data *qca = hu->priv;
860 	struct sk_buff *skb;
861 	u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 };
862 
863 	if (baudrate > QCA_BAUDRATE_3000000)
864 		return -EINVAL;
865 
866 	cmd[4] = baudrate;
867 
868 	skb = bt_skb_alloc(sizeof(cmd), GFP_ATOMIC);
869 	if (!skb) {
870 		BT_ERR("Failed to allocate memory for baudrate packet");
871 		return -ENOMEM;
872 	}
873 
874 	/* Assign commands to change baudrate and packet type. */
875 	memcpy(skb_put(skb, sizeof(cmd)), cmd, sizeof(cmd));
876 	bt_cb(skb)->pkt_type = HCI_COMMAND_PKT;
877 
878 	skb_queue_tail(&qca->txq, skb);
879 	hci_uart_tx_wakeup(hu);
880 
881 	/* wait 300ms to change new baudrate on controller side
882 	 * controller will come back after they receive this HCI command
883 	 * then host can communicate with new baudrate to controller
884 	 */
885 	set_current_state(TASK_UNINTERRUPTIBLE);
886 	schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS));
887 	set_current_state(TASK_RUNNING);
888 
889 	return 0;
890 }
891 
qca_setup(struct hci_uart * hu)892 static int qca_setup(struct hci_uart *hu)
893 {
894 	struct hci_dev *hdev = hu->hdev;
895 	struct qca_data *qca = hu->priv;
896 	unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
897 	int ret;
898 
899 	BT_INFO("%s: ROME setup", hdev->name);
900 
901 	/* Patch downloading has to be done without IBS mode */
902 	clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
903 
904 	/* Setup initial baudrate */
905 	speed = 0;
906 	if (hu->init_speed)
907 		speed = hu->init_speed;
908 	else if (hu->proto->init_speed)
909 		speed = hu->proto->init_speed;
910 
911 	if (speed)
912 		hci_uart_set_baudrate(hu, speed);
913 
914 	/* Setup user speed if needed */
915 	speed = 0;
916 	if (hu->oper_speed)
917 		speed = hu->oper_speed;
918 	else if (hu->proto->oper_speed)
919 		speed = hu->proto->oper_speed;
920 
921 	if (speed) {
922 		qca_baudrate = qca_get_baudrate_value(speed);
923 
924 		BT_INFO("%s: Set UART speed to %d", hdev->name, speed);
925 		ret = qca_set_baudrate(hdev, qca_baudrate);
926 		if (ret) {
927 			BT_ERR("%s: Failed to change the baud rate (%d)",
928 			       hdev->name, ret);
929 			return ret;
930 		}
931 		hci_uart_set_baudrate(hu, speed);
932 	}
933 
934 	/* Setup patch / NVM configurations */
935 	ret = qca_uart_setup_rome(hdev, qca_baudrate);
936 	if (!ret) {
937 		set_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
938 		qca_debugfs_init(hdev);
939 	} else if (ret == -ENOENT) {
940 		/* No patch/nvm-config found, run with original fw/config */
941 		ret = 0;
942 	} else if (ret == -EAGAIN) {
943 		/*
944 		 * Userspace firmware loader will return -EAGAIN in case no
945 		 * patch/nvm-config is found, so run with original fw/config.
946 		 */
947 		ret = 0;
948 	}
949 
950 	/* Setup bdaddr */
951 	hu->hdev->set_bdaddr = qca_set_bdaddr_rome;
952 
953 	return ret;
954 }
955 
956 static struct hci_uart_proto qca_proto = {
957 	.id		= HCI_UART_QCA,
958 	.name		= "QCA",
959 	.manufacturer	= 29,
960 	.init_speed	= 115200,
961 	.oper_speed	= 3000000,
962 	.open		= qca_open,
963 	.close		= qca_close,
964 	.flush		= qca_flush,
965 	.setup		= qca_setup,
966 	.recv		= qca_recv,
967 	.enqueue	= qca_enqueue,
968 	.dequeue	= qca_dequeue,
969 };
970 
qca_init(void)971 int __init qca_init(void)
972 {
973 	return hci_uart_register_proto(&qca_proto);
974 }
975 
qca_deinit(void)976 int __exit qca_deinit(void)
977 {
978 	return hci_uart_unregister_proto(&qca_proto);
979 }
980