xref: /openbmc/linux/drivers/bluetooth/hci_ll.c (revision e2c75e76)
1 /*
2  *  Texas Instruments' Bluetooth HCILL UART protocol
3  *
4  *  HCILL (HCI Low Level) is a Texas Instruments' power management
5  *  protocol extension to H4.
6  *
7  *  Copyright (C) 2007 Texas Instruments, Inc.
8  *
9  *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
10  *
11  *  Acknowledgements:
12  *  This file is based on hci_h4.c, which was written
13  *  by Maxim Krasnyansky and Marcel Holtmann.
14  *
15  *  This program is free software; you can redistribute it and/or modify
16  *  it under the terms of the GNU General Public License version 2
17  *  as published by the Free Software Foundation
18  *
19  *  This program is distributed in the hope that it will be useful,
20  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  *  GNU General Public License for more details.
23  *
24  *  You should have received a copy of the GNU General Public License
25  *  along with this program; if not, write to the Free Software
26  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
27  *
28  */
29 
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 
33 #include <linux/init.h>
34 #include <linux/sched.h>
35 #include <linux/types.h>
36 #include <linux/fcntl.h>
37 #include <linux/firmware.h>
38 #include <linux/interrupt.h>
39 #include <linux/ptrace.h>
40 #include <linux/poll.h>
41 
42 #include <linux/slab.h>
43 #include <linux/errno.h>
44 #include <linux/string.h>
45 #include <linux/signal.h>
46 #include <linux/ioctl.h>
47 #include <linux/of.h>
48 #include <linux/serdev.h>
49 #include <linux/skbuff.h>
50 #include <linux/ti_wilink_st.h>
51 #include <linux/clk.h>
52 
53 #include <net/bluetooth/bluetooth.h>
54 #include <net/bluetooth/hci_core.h>
55 #include <linux/gpio/consumer.h>
56 #include <linux/nvmem-consumer.h>
57 
58 #include "hci_uart.h"
59 
60 /* Vendor-specific HCI commands */
61 #define HCI_VS_WRITE_BD_ADDR			0xfc06
62 #define HCI_VS_UPDATE_UART_HCI_BAUDRATE		0xff36
63 
64 /* HCILL commands */
65 #define HCILL_GO_TO_SLEEP_IND	0x30
66 #define HCILL_GO_TO_SLEEP_ACK	0x31
67 #define HCILL_WAKE_UP_IND	0x32
68 #define HCILL_WAKE_UP_ACK	0x33
69 
70 /* HCILL receiver States */
71 #define HCILL_W4_PACKET_TYPE	0
72 #define HCILL_W4_EVENT_HDR	1
73 #define HCILL_W4_ACL_HDR	2
74 #define HCILL_W4_SCO_HDR	3
75 #define HCILL_W4_DATA		4
76 
77 /* HCILL states */
78 enum hcill_states_e {
79 	HCILL_ASLEEP,
80 	HCILL_ASLEEP_TO_AWAKE,
81 	HCILL_AWAKE,
82 	HCILL_AWAKE_TO_ASLEEP
83 };
84 
85 struct hcill_cmd {
86 	u8 cmd;
87 } __packed;
88 
89 struct ll_device {
90 	struct hci_uart hu;
91 	struct serdev_device *serdev;
92 	struct gpio_desc *enable_gpio;
93 	struct clk *ext_clk;
94 	bdaddr_t bdaddr;
95 };
96 
97 struct ll_struct {
98 	unsigned long rx_state;
99 	unsigned long rx_count;
100 	struct sk_buff *rx_skb;
101 	struct sk_buff_head txq;
102 	spinlock_t hcill_lock;		/* HCILL state lock	*/
103 	unsigned long hcill_state;	/* HCILL power state	*/
104 	struct sk_buff_head tx_wait_q;	/* HCILL wait queue	*/
105 };
106 
107 /*
108  * Builds and sends an HCILL command packet.
109  * These are very simple packets with only 1 cmd byte
110  */
111 static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
112 {
113 	int err = 0;
114 	struct sk_buff *skb = NULL;
115 	struct ll_struct *ll = hu->priv;
116 	struct hcill_cmd *hcill_packet;
117 
118 	BT_DBG("hu %p cmd 0x%x", hu, cmd);
119 
120 	/* allocate packet */
121 	skb = bt_skb_alloc(1, GFP_ATOMIC);
122 	if (!skb) {
123 		BT_ERR("cannot allocate memory for HCILL packet");
124 		err = -ENOMEM;
125 		goto out;
126 	}
127 
128 	/* prepare packet */
129 	hcill_packet = skb_put(skb, 1);
130 	hcill_packet->cmd = cmd;
131 
132 	/* send packet */
133 	skb_queue_tail(&ll->txq, skb);
134 out:
135 	return err;
136 }
137 
138 /* Initialize protocol */
139 static int ll_open(struct hci_uart *hu)
140 {
141 	struct ll_struct *ll;
142 
143 	BT_DBG("hu %p", hu);
144 
145 	ll = kzalloc(sizeof(*ll), GFP_KERNEL);
146 	if (!ll)
147 		return -ENOMEM;
148 
149 	skb_queue_head_init(&ll->txq);
150 	skb_queue_head_init(&ll->tx_wait_q);
151 	spin_lock_init(&ll->hcill_lock);
152 
153 	ll->hcill_state = HCILL_AWAKE;
154 
155 	hu->priv = ll;
156 
157 	if (hu->serdev) {
158 		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
159 		serdev_device_open(hu->serdev);
160 		if (!IS_ERR(lldev->ext_clk))
161 			clk_prepare_enable(lldev->ext_clk);
162 	}
163 
164 	return 0;
165 }
166 
167 /* Flush protocol data */
168 static int ll_flush(struct hci_uart *hu)
169 {
170 	struct ll_struct *ll = hu->priv;
171 
172 	BT_DBG("hu %p", hu);
173 
174 	skb_queue_purge(&ll->tx_wait_q);
175 	skb_queue_purge(&ll->txq);
176 
177 	return 0;
178 }
179 
180 /* Close protocol */
181 static int ll_close(struct hci_uart *hu)
182 {
183 	struct ll_struct *ll = hu->priv;
184 
185 	BT_DBG("hu %p", hu);
186 
187 	skb_queue_purge(&ll->tx_wait_q);
188 	skb_queue_purge(&ll->txq);
189 
190 	kfree_skb(ll->rx_skb);
191 
192 	if (hu->serdev) {
193 		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
194 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
195 
196 		clk_disable_unprepare(lldev->ext_clk);
197 
198 		serdev_device_close(hu->serdev);
199 	}
200 
201 	hu->priv = NULL;
202 
203 	kfree(ll);
204 
205 	return 0;
206 }
207 
208 /*
209  * internal function, which does common work of the device wake up process:
210  * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
211  * 2. changes internal state to HCILL_AWAKE.
212  * Note: assumes that hcill_lock spinlock is taken,
213  * shouldn't be called otherwise!
214  */
215 static void __ll_do_awake(struct ll_struct *ll)
216 {
217 	struct sk_buff *skb = NULL;
218 
219 	while ((skb = skb_dequeue(&ll->tx_wait_q)))
220 		skb_queue_tail(&ll->txq, skb);
221 
222 	ll->hcill_state = HCILL_AWAKE;
223 }
224 
225 /*
226  * Called upon a wake-up-indication from the device
227  */
228 static void ll_device_want_to_wakeup(struct hci_uart *hu)
229 {
230 	unsigned long flags;
231 	struct ll_struct *ll = hu->priv;
232 
233 	BT_DBG("hu %p", hu);
234 
235 	/* lock hcill state */
236 	spin_lock_irqsave(&ll->hcill_lock, flags);
237 
238 	switch (ll->hcill_state) {
239 	case HCILL_ASLEEP_TO_AWAKE:
240 		/*
241 		 * This state means that both the host and the BRF chip
242 		 * have simultaneously sent a wake-up-indication packet.
243 		 * Traditionally, in this case, receiving a wake-up-indication
244 		 * was enough and an additional wake-up-ack wasn't needed.
245 		 * This has changed with the BRF6350, which does require an
246 		 * explicit wake-up-ack. Other BRF versions, which do not
247 		 * require an explicit ack here, do accept it, thus it is
248 		 * perfectly safe to always send one.
249 		 */
250 		BT_DBG("dual wake-up-indication");
251 		/* fall through */
252 	case HCILL_ASLEEP:
253 		/* acknowledge device wake up */
254 		if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
255 			BT_ERR("cannot acknowledge device wake up");
256 			goto out;
257 		}
258 		break;
259 	default:
260 		/* any other state is illegal */
261 		BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
262 		break;
263 	}
264 
265 	/* send pending packets and change state to HCILL_AWAKE */
266 	__ll_do_awake(ll);
267 
268 out:
269 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
270 
271 	/* actually send the packets */
272 	hci_uart_tx_wakeup(hu);
273 }
274 
275 /*
276  * Called upon a sleep-indication from the device
277  */
278 static void ll_device_want_to_sleep(struct hci_uart *hu)
279 {
280 	unsigned long flags;
281 	struct ll_struct *ll = hu->priv;
282 
283 	BT_DBG("hu %p", hu);
284 
285 	/* lock hcill state */
286 	spin_lock_irqsave(&ll->hcill_lock, flags);
287 
288 	/* sanity check */
289 	if (ll->hcill_state != HCILL_AWAKE)
290 		BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
291 
292 	/* acknowledge device sleep */
293 	if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
294 		BT_ERR("cannot acknowledge device sleep");
295 		goto out;
296 	}
297 
298 	/* update state */
299 	ll->hcill_state = HCILL_ASLEEP;
300 
301 out:
302 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
303 
304 	/* actually send the sleep ack packet */
305 	hci_uart_tx_wakeup(hu);
306 }
307 
308 /*
309  * Called upon wake-up-acknowledgement from the device
310  */
311 static void ll_device_woke_up(struct hci_uart *hu)
312 {
313 	unsigned long flags;
314 	struct ll_struct *ll = hu->priv;
315 
316 	BT_DBG("hu %p", hu);
317 
318 	/* lock hcill state */
319 	spin_lock_irqsave(&ll->hcill_lock, flags);
320 
321 	/* sanity check */
322 	if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
323 		BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
324 
325 	/* send pending packets and change state to HCILL_AWAKE */
326 	__ll_do_awake(ll);
327 
328 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
329 
330 	/* actually send the packets */
331 	hci_uart_tx_wakeup(hu);
332 }
333 
334 /* Enqueue frame for transmittion (padding, crc, etc) */
335 /* may be called from two simultaneous tasklets */
336 static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
337 {
338 	unsigned long flags = 0;
339 	struct ll_struct *ll = hu->priv;
340 
341 	BT_DBG("hu %p skb %p", hu, skb);
342 
343 	/* Prepend skb with frame type */
344 	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
345 
346 	/* lock hcill state */
347 	spin_lock_irqsave(&ll->hcill_lock, flags);
348 
349 	/* act according to current state */
350 	switch (ll->hcill_state) {
351 	case HCILL_AWAKE:
352 		BT_DBG("device awake, sending normally");
353 		skb_queue_tail(&ll->txq, skb);
354 		break;
355 	case HCILL_ASLEEP:
356 		BT_DBG("device asleep, waking up and queueing packet");
357 		/* save packet for later */
358 		skb_queue_tail(&ll->tx_wait_q, skb);
359 		/* awake device */
360 		if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
361 			BT_ERR("cannot wake up device");
362 			break;
363 		}
364 		ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
365 		break;
366 	case HCILL_ASLEEP_TO_AWAKE:
367 		BT_DBG("device waking up, queueing packet");
368 		/* transient state; just keep packet for later */
369 		skb_queue_tail(&ll->tx_wait_q, skb);
370 		break;
371 	default:
372 		BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
373 		kfree_skb(skb);
374 		break;
375 	}
376 
377 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
378 
379 	return 0;
380 }
381 
382 static inline int ll_check_data_len(struct hci_dev *hdev, struct ll_struct *ll, int len)
383 {
384 	int room = skb_tailroom(ll->rx_skb);
385 
386 	BT_DBG("len %d room %d", len, room);
387 
388 	if (!len) {
389 		hci_recv_frame(hdev, ll->rx_skb);
390 	} else if (len > room) {
391 		BT_ERR("Data length is too large");
392 		kfree_skb(ll->rx_skb);
393 	} else {
394 		ll->rx_state = HCILL_W4_DATA;
395 		ll->rx_count = len;
396 		return len;
397 	}
398 
399 	ll->rx_state = HCILL_W4_PACKET_TYPE;
400 	ll->rx_skb   = NULL;
401 	ll->rx_count = 0;
402 
403 	return 0;
404 }
405 
406 /* Recv data */
407 static int ll_recv(struct hci_uart *hu, const void *data, int count)
408 {
409 	struct ll_struct *ll = hu->priv;
410 	const char *ptr;
411 	struct hci_event_hdr *eh;
412 	struct hci_acl_hdr   *ah;
413 	struct hci_sco_hdr   *sh;
414 	int len, type, dlen;
415 
416 	BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu, count, ll->rx_state, ll->rx_count);
417 
418 	ptr = data;
419 	while (count) {
420 		if (ll->rx_count) {
421 			len = min_t(unsigned int, ll->rx_count, count);
422 			skb_put_data(ll->rx_skb, ptr, len);
423 			ll->rx_count -= len; count -= len; ptr += len;
424 
425 			if (ll->rx_count)
426 				continue;
427 
428 			switch (ll->rx_state) {
429 			case HCILL_W4_DATA:
430 				BT_DBG("Complete data");
431 				hci_recv_frame(hu->hdev, ll->rx_skb);
432 
433 				ll->rx_state = HCILL_W4_PACKET_TYPE;
434 				ll->rx_skb = NULL;
435 				continue;
436 
437 			case HCILL_W4_EVENT_HDR:
438 				eh = hci_event_hdr(ll->rx_skb);
439 
440 				BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
441 
442 				ll_check_data_len(hu->hdev, ll, eh->plen);
443 				continue;
444 
445 			case HCILL_W4_ACL_HDR:
446 				ah = hci_acl_hdr(ll->rx_skb);
447 				dlen = __le16_to_cpu(ah->dlen);
448 
449 				BT_DBG("ACL header: dlen %d", dlen);
450 
451 				ll_check_data_len(hu->hdev, ll, dlen);
452 				continue;
453 
454 			case HCILL_W4_SCO_HDR:
455 				sh = hci_sco_hdr(ll->rx_skb);
456 
457 				BT_DBG("SCO header: dlen %d", sh->dlen);
458 
459 				ll_check_data_len(hu->hdev, ll, sh->dlen);
460 				continue;
461 			}
462 		}
463 
464 		/* HCILL_W4_PACKET_TYPE */
465 		switch (*ptr) {
466 		case HCI_EVENT_PKT:
467 			BT_DBG("Event packet");
468 			ll->rx_state = HCILL_W4_EVENT_HDR;
469 			ll->rx_count = HCI_EVENT_HDR_SIZE;
470 			type = HCI_EVENT_PKT;
471 			break;
472 
473 		case HCI_ACLDATA_PKT:
474 			BT_DBG("ACL packet");
475 			ll->rx_state = HCILL_W4_ACL_HDR;
476 			ll->rx_count = HCI_ACL_HDR_SIZE;
477 			type = HCI_ACLDATA_PKT;
478 			break;
479 
480 		case HCI_SCODATA_PKT:
481 			BT_DBG("SCO packet");
482 			ll->rx_state = HCILL_W4_SCO_HDR;
483 			ll->rx_count = HCI_SCO_HDR_SIZE;
484 			type = HCI_SCODATA_PKT;
485 			break;
486 
487 		/* HCILL signals */
488 		case HCILL_GO_TO_SLEEP_IND:
489 			BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
490 			ll_device_want_to_sleep(hu);
491 			ptr++; count--;
492 			continue;
493 
494 		case HCILL_GO_TO_SLEEP_ACK:
495 			/* shouldn't happen */
496 			BT_ERR("received HCILL_GO_TO_SLEEP_ACK (in state %ld)", ll->hcill_state);
497 			ptr++; count--;
498 			continue;
499 
500 		case HCILL_WAKE_UP_IND:
501 			BT_DBG("HCILL_WAKE_UP_IND packet");
502 			ll_device_want_to_wakeup(hu);
503 			ptr++; count--;
504 			continue;
505 
506 		case HCILL_WAKE_UP_ACK:
507 			BT_DBG("HCILL_WAKE_UP_ACK packet");
508 			ll_device_woke_up(hu);
509 			ptr++; count--;
510 			continue;
511 
512 		default:
513 			BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
514 			hu->hdev->stat.err_rx++;
515 			ptr++; count--;
516 			continue;
517 		}
518 
519 		ptr++; count--;
520 
521 		/* Allocate packet */
522 		ll->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
523 		if (!ll->rx_skb) {
524 			BT_ERR("Can't allocate mem for new packet");
525 			ll->rx_state = HCILL_W4_PACKET_TYPE;
526 			ll->rx_count = 0;
527 			return -ENOMEM;
528 		}
529 
530 		hci_skb_pkt_type(ll->rx_skb) = type;
531 	}
532 
533 	return count;
534 }
535 
536 static struct sk_buff *ll_dequeue(struct hci_uart *hu)
537 {
538 	struct ll_struct *ll = hu->priv;
539 	return skb_dequeue(&ll->txq);
540 }
541 
542 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
543 static int read_local_version(struct hci_dev *hdev)
544 {
545 	int err = 0;
546 	unsigned short version = 0;
547 	struct sk_buff *skb;
548 	struct hci_rp_read_local_version *ver;
549 
550 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL, HCI_INIT_TIMEOUT);
551 	if (IS_ERR(skb)) {
552 		bt_dev_err(hdev, "Reading TI version information failed (%ld)",
553 			   PTR_ERR(skb));
554 		return PTR_ERR(skb);
555 	}
556 	if (skb->len != sizeof(*ver)) {
557 		err = -EILSEQ;
558 		goto out;
559 	}
560 
561 	ver = (struct hci_rp_read_local_version *)skb->data;
562 	if (le16_to_cpu(ver->manufacturer) != 13) {
563 		err = -ENODEV;
564 		goto out;
565 	}
566 
567 	version = le16_to_cpu(ver->lmp_subver);
568 
569 out:
570 	if (err) bt_dev_err(hdev, "Failed to read TI version info: %d", err);
571 	kfree_skb(skb);
572 	return err ? err : version;
573 }
574 
575 /**
576  * download_firmware -
577  *	internal function which parses through the .bts firmware
578  *	script file intreprets SEND, DELAY actions only as of now
579  */
580 static int download_firmware(struct ll_device *lldev)
581 {
582 	unsigned short chip, min_ver, maj_ver;
583 	int version, err, len;
584 	unsigned char *ptr, *action_ptr;
585 	unsigned char bts_scr_name[40];	/* 40 char long bts scr name? */
586 	const struct firmware *fw;
587 	struct sk_buff *skb;
588 	struct hci_command *cmd;
589 
590 	version = read_local_version(lldev->hu.hdev);
591 	if (version < 0)
592 		return version;
593 
594 	chip = (version & 0x7C00) >> 10;
595 	min_ver = (version & 0x007F);
596 	maj_ver = (version & 0x0380) >> 7;
597 	if (version & 0x8000)
598 		maj_ver |= 0x0008;
599 
600 	snprintf(bts_scr_name, sizeof(bts_scr_name),
601 		 "ti-connectivity/TIInit_%d.%d.%d.bts",
602 		 chip, maj_ver, min_ver);
603 
604 	err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
605 	if (err || !fw->data || !fw->size) {
606 		bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
607 			   err, bts_scr_name);
608 		return -EINVAL;
609 	}
610 	ptr = (void *)fw->data;
611 	len = fw->size;
612 	/* bts_header to remove out magic number and
613 	 * version
614 	 */
615 	ptr += sizeof(struct bts_header);
616 	len -= sizeof(struct bts_header);
617 
618 	while (len > 0 && ptr) {
619 		bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
620 			   ((struct bts_action *)ptr)->size,
621 			   ((struct bts_action *)ptr)->type);
622 
623 		action_ptr = &(((struct bts_action *)ptr)->data[0]);
624 
625 		switch (((struct bts_action *)ptr)->type) {
626 		case ACTION_SEND_COMMAND:	/* action send */
627 			bt_dev_dbg(lldev->hu.hdev, "S");
628 			cmd = (struct hci_command *)action_ptr;
629 			if (cmd->opcode == HCI_VS_UPDATE_UART_HCI_BAUDRATE) {
630 				/* ignore remote change
631 				 * baud rate HCI VS command
632 				 */
633 				bt_dev_warn(lldev->hu.hdev, "change remote baud rate command in firmware");
634 				break;
635 			}
636 			if (cmd->prefix != 1)
637 				bt_dev_dbg(lldev->hu.hdev, "command type %d", cmd->prefix);
638 
639 			skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen, &cmd->speed, HCI_INIT_TIMEOUT);
640 			if (IS_ERR(skb)) {
641 				bt_dev_err(lldev->hu.hdev, "send command failed");
642 				err = PTR_ERR(skb);
643 				goto out_rel_fw;
644 			}
645 			kfree_skb(skb);
646 			break;
647 		case ACTION_WAIT_EVENT:  /* wait */
648 			/* no need to wait as command was synchronous */
649 			bt_dev_dbg(lldev->hu.hdev, "W");
650 			break;
651 		case ACTION_DELAY:	/* sleep */
652 			bt_dev_info(lldev->hu.hdev, "sleep command in scr");
653 			mdelay(((struct bts_action_delay *)action_ptr)->msec);
654 			break;
655 		}
656 		len -= (sizeof(struct bts_action) +
657 			((struct bts_action *)ptr)->size);
658 		ptr += sizeof(struct bts_action) +
659 			((struct bts_action *)ptr)->size;
660 	}
661 
662 out_rel_fw:
663 	/* fw download complete */
664 	release_firmware(fw);
665 	return err;
666 }
667 
668 static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
669 {
670 	bdaddr_t bdaddr_swapped;
671 	struct sk_buff *skb;
672 
673 	/* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
674 	 * address to be MSB first, but bdaddr_t has the convention of being
675 	 * LSB first.
676 	 */
677 	baswap(&bdaddr_swapped, bdaddr);
678 	skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
679 			     &bdaddr_swapped, HCI_INIT_TIMEOUT);
680 	if (!IS_ERR(skb))
681 		kfree_skb(skb);
682 
683 	return PTR_ERR_OR_ZERO(skb);
684 }
685 
686 static int ll_setup(struct hci_uart *hu)
687 {
688 	int err, retry = 3;
689 	struct ll_device *lldev;
690 	struct serdev_device *serdev = hu->serdev;
691 	u32 speed;
692 
693 	if (!serdev)
694 		return 0;
695 
696 	lldev = serdev_device_get_drvdata(serdev);
697 
698 	hu->hdev->set_bdaddr = ll_set_bdaddr;
699 
700 	serdev_device_set_flow_control(serdev, true);
701 
702 	do {
703 		/* Reset the Bluetooth device */
704 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
705 		msleep(5);
706 		gpiod_set_value_cansleep(lldev->enable_gpio, 1);
707 		err = serdev_device_wait_for_cts(serdev, true, 200);
708 		if (err) {
709 			bt_dev_err(hu->hdev, "Failed to get CTS");
710 			return err;
711 		}
712 
713 		err = download_firmware(lldev);
714 		if (!err)
715 			break;
716 
717 		/* Toggle BT_EN and retry */
718 		bt_dev_err(hu->hdev, "download firmware failed, retrying...");
719 	} while (retry--);
720 
721 	if (err)
722 		return err;
723 
724 	/* Set BD address if one was specified at probe */
725 	if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
726 		/* This means that there was an error getting the BD address
727 		 * during probe, so mark the device as having a bad address.
728 		 */
729 		set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
730 	} else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
731 		err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
732 		if (err)
733 			set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
734 	}
735 
736 	/* Operational speed if any */
737 	if (hu->oper_speed)
738 		speed = hu->oper_speed;
739 	else if (hu->proto->oper_speed)
740 		speed = hu->proto->oper_speed;
741 	else
742 		speed = 0;
743 
744 	if (speed) {
745 		__le32 speed_le = cpu_to_le32(speed);
746 		struct sk_buff *skb;
747 
748 		skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
749 				     sizeof(speed_le), &speed_le,
750 				     HCI_INIT_TIMEOUT);
751 		if (!IS_ERR(skb)) {
752 			kfree_skb(skb);
753 			serdev_device_set_baudrate(serdev, speed);
754 		}
755 	}
756 
757 	return 0;
758 }
759 
760 static const struct hci_uart_proto llp;
761 
762 static int hci_ti_probe(struct serdev_device *serdev)
763 {
764 	struct hci_uart *hu;
765 	struct ll_device *lldev;
766 	struct nvmem_cell *bdaddr_cell;
767 	u32 max_speed = 3000000;
768 
769 	lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
770 	if (!lldev)
771 		return -ENOMEM;
772 	hu = &lldev->hu;
773 
774 	serdev_device_set_drvdata(serdev, lldev);
775 	lldev->serdev = hu->serdev = serdev;
776 
777 	lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev, "enable", GPIOD_OUT_LOW);
778 	if (IS_ERR(lldev->enable_gpio))
779 		return PTR_ERR(lldev->enable_gpio);
780 
781 	lldev->ext_clk = devm_clk_get(&serdev->dev, "ext_clock");
782 	if (IS_ERR(lldev->ext_clk) && PTR_ERR(lldev->ext_clk) != -ENOENT)
783 		return PTR_ERR(lldev->ext_clk);
784 
785 	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
786 	hci_uart_set_speeds(hu, 115200, max_speed);
787 
788 	/* optional BD address from nvram */
789 	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
790 	if (IS_ERR(bdaddr_cell)) {
791 		int err = PTR_ERR(bdaddr_cell);
792 
793 		if (err == -EPROBE_DEFER)
794 			return err;
795 
796 		/* ENOENT means there is no matching nvmem cell and ENOSYS
797 		 * means that nvmem is not enabled in the kernel configuration.
798 		 */
799 		if (err != -ENOENT && err != -ENOSYS) {
800 			/* If there was some other error, give userspace a
801 			 * chance to fix the problem instead of failing to load
802 			 * the driver. Using BDADDR_NONE as a flag that is
803 			 * tested later in the setup function.
804 			 */
805 			dev_warn(&serdev->dev,
806 				 "Failed to get \"bd-address\" nvmem cell (%d)\n",
807 				 err);
808 			bacpy(&lldev->bdaddr, BDADDR_NONE);
809 		}
810 	} else {
811 		bdaddr_t *bdaddr;
812 		size_t len;
813 
814 		bdaddr = nvmem_cell_read(bdaddr_cell, &len);
815 		nvmem_cell_put(bdaddr_cell);
816 		if (IS_ERR(bdaddr)) {
817 			dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
818 			return PTR_ERR(bdaddr);
819 		}
820 		if (len != sizeof(bdaddr_t)) {
821 			dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
822 			kfree(bdaddr);
823 			return -EINVAL;
824 		}
825 
826 		/* As per the device tree bindings, the value from nvmem is
827 		 * expected to be MSB first, but in the kernel it is expected
828 		 * that bdaddr_t is LSB first.
829 		 */
830 		baswap(&lldev->bdaddr, bdaddr);
831 		kfree(bdaddr);
832 	}
833 
834 	return hci_uart_register_device(hu, &llp);
835 }
836 
837 static void hci_ti_remove(struct serdev_device *serdev)
838 {
839 	struct ll_device *lldev = serdev_device_get_drvdata(serdev);
840 
841 	hci_uart_unregister_device(&lldev->hu);
842 }
843 
844 static const struct of_device_id hci_ti_of_match[] = {
845 	{ .compatible = "ti,cc2560" },
846 	{ .compatible = "ti,wl1271-st" },
847 	{ .compatible = "ti,wl1273-st" },
848 	{ .compatible = "ti,wl1281-st" },
849 	{ .compatible = "ti,wl1283-st" },
850 	{ .compatible = "ti,wl1285-st" },
851 	{ .compatible = "ti,wl1801-st" },
852 	{ .compatible = "ti,wl1805-st" },
853 	{ .compatible = "ti,wl1807-st" },
854 	{ .compatible = "ti,wl1831-st" },
855 	{ .compatible = "ti,wl1835-st" },
856 	{ .compatible = "ti,wl1837-st" },
857 	{},
858 };
859 MODULE_DEVICE_TABLE(of, hci_ti_of_match);
860 
861 static struct serdev_device_driver hci_ti_drv = {
862 	.driver		= {
863 		.name	= "hci-ti",
864 		.of_match_table = of_match_ptr(hci_ti_of_match),
865 	},
866 	.probe	= hci_ti_probe,
867 	.remove	= hci_ti_remove,
868 };
869 #else
870 #define ll_setup NULL
871 #endif
872 
873 static const struct hci_uart_proto llp = {
874 	.id		= HCI_UART_LL,
875 	.name		= "LL",
876 	.setup		= ll_setup,
877 	.open		= ll_open,
878 	.close		= ll_close,
879 	.recv		= ll_recv,
880 	.enqueue	= ll_enqueue,
881 	.dequeue	= ll_dequeue,
882 	.flush		= ll_flush,
883 };
884 
885 int __init ll_init(void)
886 {
887 	serdev_device_driver_register(&hci_ti_drv);
888 
889 	return hci_uart_register_proto(&llp);
890 }
891 
892 int __exit ll_deinit(void)
893 {
894 	serdev_device_driver_unregister(&hci_ti_drv);
895 
896 	return hci_uart_unregister_proto(&llp);
897 }
898