xref: /openbmc/linux/drivers/bluetooth/hci_ll.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Texas Instruments' Bluetooth HCILL UART protocol
4  *
5  *  HCILL (HCI Low Level) is a Texas Instruments' power management
6  *  protocol extension to H4.
7  *
8  *  Copyright (C) 2007 Texas Instruments, Inc.
9  *
10  *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
11  *
12  *  Acknowledgements:
13  *  This file is based on hci_h4.c, which was written
14  *  by Maxim Krasnyansky and Marcel Holtmann.
15  */
16 
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 
20 #include <linux/init.h>
21 #include <linux/sched.h>
22 #include <linux/types.h>
23 #include <linux/fcntl.h>
24 #include <linux/firmware.h>
25 #include <linux/interrupt.h>
26 #include <linux/ptrace.h>
27 #include <linux/poll.h>
28 
29 #include <linux/slab.h>
30 #include <linux/errno.h>
31 #include <linux/string.h>
32 #include <linux/signal.h>
33 #include <linux/ioctl.h>
34 #include <linux/of.h>
35 #include <linux/serdev.h>
36 #include <linux/skbuff.h>
37 #include <linux/ti_wilink_st.h>
38 #include <linux/clk.h>
39 
40 #include <net/bluetooth/bluetooth.h>
41 #include <net/bluetooth/hci_core.h>
42 #include <linux/gpio/consumer.h>
43 #include <linux/nvmem-consumer.h>
44 
45 #include "hci_uart.h"
46 
47 /* Vendor-specific HCI commands */
48 #define HCI_VS_WRITE_BD_ADDR			0xfc06
49 #define HCI_VS_UPDATE_UART_HCI_BAUDRATE		0xff36
50 
51 /* HCILL commands */
52 #define HCILL_GO_TO_SLEEP_IND	0x30
53 #define HCILL_GO_TO_SLEEP_ACK	0x31
54 #define HCILL_WAKE_UP_IND	0x32
55 #define HCILL_WAKE_UP_ACK	0x33
56 
57 /* HCILL states */
58 enum hcill_states_e {
59 	HCILL_ASLEEP,
60 	HCILL_ASLEEP_TO_AWAKE,
61 	HCILL_AWAKE,
62 	HCILL_AWAKE_TO_ASLEEP
63 };
64 
65 struct ll_device {
66 	struct hci_uart hu;
67 	struct serdev_device *serdev;
68 	struct gpio_desc *enable_gpio;
69 	struct clk *ext_clk;
70 	bdaddr_t bdaddr;
71 };
72 
73 struct ll_struct {
74 	struct sk_buff *rx_skb;
75 	struct sk_buff_head txq;
76 	spinlock_t hcill_lock;		/* HCILL state lock	*/
77 	unsigned long hcill_state;	/* HCILL power state	*/
78 	struct sk_buff_head tx_wait_q;	/* HCILL wait queue	*/
79 };
80 
81 /*
82  * Builds and sends an HCILL command packet.
83  * These are very simple packets with only 1 cmd byte
84  */
85 static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
86 {
87 	int err = 0;
88 	struct sk_buff *skb = NULL;
89 	struct ll_struct *ll = hu->priv;
90 
91 	BT_DBG("hu %p cmd 0x%x", hu, cmd);
92 
93 	/* allocate packet */
94 	skb = bt_skb_alloc(1, GFP_ATOMIC);
95 	if (!skb) {
96 		BT_ERR("cannot allocate memory for HCILL packet");
97 		err = -ENOMEM;
98 		goto out;
99 	}
100 
101 	/* prepare packet */
102 	skb_put_u8(skb, cmd);
103 
104 	/* send packet */
105 	skb_queue_tail(&ll->txq, skb);
106 out:
107 	return err;
108 }
109 
110 /* Initialize protocol */
111 static int ll_open(struct hci_uart *hu)
112 {
113 	struct ll_struct *ll;
114 
115 	BT_DBG("hu %p", hu);
116 
117 	ll = kzalloc(sizeof(*ll), GFP_KERNEL);
118 	if (!ll)
119 		return -ENOMEM;
120 
121 	skb_queue_head_init(&ll->txq);
122 	skb_queue_head_init(&ll->tx_wait_q);
123 	spin_lock_init(&ll->hcill_lock);
124 
125 	ll->hcill_state = HCILL_AWAKE;
126 
127 	hu->priv = ll;
128 
129 	if (hu->serdev) {
130 		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
131 
132 		if (!IS_ERR(lldev->ext_clk))
133 			clk_prepare_enable(lldev->ext_clk);
134 	}
135 
136 	return 0;
137 }
138 
139 /* Flush protocol data */
140 static int ll_flush(struct hci_uart *hu)
141 {
142 	struct ll_struct *ll = hu->priv;
143 
144 	BT_DBG("hu %p", hu);
145 
146 	skb_queue_purge(&ll->tx_wait_q);
147 	skb_queue_purge(&ll->txq);
148 
149 	return 0;
150 }
151 
152 /* Close protocol */
153 static int ll_close(struct hci_uart *hu)
154 {
155 	struct ll_struct *ll = hu->priv;
156 
157 	BT_DBG("hu %p", hu);
158 
159 	skb_queue_purge(&ll->tx_wait_q);
160 	skb_queue_purge(&ll->txq);
161 
162 	kfree_skb(ll->rx_skb);
163 
164 	if (hu->serdev) {
165 		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
166 
167 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
168 
169 		clk_disable_unprepare(lldev->ext_clk);
170 	}
171 
172 	hu->priv = NULL;
173 
174 	kfree(ll);
175 
176 	return 0;
177 }
178 
179 /*
180  * internal function, which does common work of the device wake up process:
181  * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
182  * 2. changes internal state to HCILL_AWAKE.
183  * Note: assumes that hcill_lock spinlock is taken,
184  * shouldn't be called otherwise!
185  */
186 static void __ll_do_awake(struct ll_struct *ll)
187 {
188 	struct sk_buff *skb = NULL;
189 
190 	while ((skb = skb_dequeue(&ll->tx_wait_q)))
191 		skb_queue_tail(&ll->txq, skb);
192 
193 	ll->hcill_state = HCILL_AWAKE;
194 }
195 
196 /*
197  * Called upon a wake-up-indication from the device
198  */
199 static void ll_device_want_to_wakeup(struct hci_uart *hu)
200 {
201 	unsigned long flags;
202 	struct ll_struct *ll = hu->priv;
203 
204 	BT_DBG("hu %p", hu);
205 
206 	/* lock hcill state */
207 	spin_lock_irqsave(&ll->hcill_lock, flags);
208 
209 	switch (ll->hcill_state) {
210 	case HCILL_ASLEEP_TO_AWAKE:
211 		/*
212 		 * This state means that both the host and the BRF chip
213 		 * have simultaneously sent a wake-up-indication packet.
214 		 * Traditionally, in this case, receiving a wake-up-indication
215 		 * was enough and an additional wake-up-ack wasn't needed.
216 		 * This has changed with the BRF6350, which does require an
217 		 * explicit wake-up-ack. Other BRF versions, which do not
218 		 * require an explicit ack here, do accept it, thus it is
219 		 * perfectly safe to always send one.
220 		 */
221 		BT_DBG("dual wake-up-indication");
222 		/* fall through */
223 	case HCILL_ASLEEP:
224 		/* acknowledge device wake up */
225 		if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
226 			BT_ERR("cannot acknowledge device wake up");
227 			goto out;
228 		}
229 		break;
230 	default:
231 		/* any other state is illegal */
232 		BT_ERR("received HCILL_WAKE_UP_IND in state %ld",
233 		       ll->hcill_state);
234 		break;
235 	}
236 
237 	/* send pending packets and change state to HCILL_AWAKE */
238 	__ll_do_awake(ll);
239 
240 out:
241 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
242 
243 	/* actually send the packets */
244 	hci_uart_tx_wakeup(hu);
245 }
246 
247 /*
248  * Called upon a sleep-indication from the device
249  */
250 static void ll_device_want_to_sleep(struct hci_uart *hu)
251 {
252 	unsigned long flags;
253 	struct ll_struct *ll = hu->priv;
254 
255 	BT_DBG("hu %p", hu);
256 
257 	/* lock hcill state */
258 	spin_lock_irqsave(&ll->hcill_lock, flags);
259 
260 	/* sanity check */
261 	if (ll->hcill_state != HCILL_AWAKE)
262 		BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld",
263 		       ll->hcill_state);
264 
265 	/* acknowledge device sleep */
266 	if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
267 		BT_ERR("cannot acknowledge device sleep");
268 		goto out;
269 	}
270 
271 	/* update state */
272 	ll->hcill_state = HCILL_ASLEEP;
273 
274 out:
275 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
276 
277 	/* actually send the sleep ack packet */
278 	hci_uart_tx_wakeup(hu);
279 }
280 
281 /*
282  * Called upon wake-up-acknowledgement from the device
283  */
284 static void ll_device_woke_up(struct hci_uart *hu)
285 {
286 	unsigned long flags;
287 	struct ll_struct *ll = hu->priv;
288 
289 	BT_DBG("hu %p", hu);
290 
291 	/* lock hcill state */
292 	spin_lock_irqsave(&ll->hcill_lock, flags);
293 
294 	/* sanity check */
295 	if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
296 		BT_ERR("received HCILL_WAKE_UP_ACK in state %ld",
297 		       ll->hcill_state);
298 
299 	/* send pending packets and change state to HCILL_AWAKE */
300 	__ll_do_awake(ll);
301 
302 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
303 
304 	/* actually send the packets */
305 	hci_uart_tx_wakeup(hu);
306 }
307 
308 /* Enqueue frame for transmittion (padding, crc, etc) */
309 /* may be called from two simultaneous tasklets */
310 static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
311 {
312 	unsigned long flags = 0;
313 	struct ll_struct *ll = hu->priv;
314 
315 	BT_DBG("hu %p skb %p", hu, skb);
316 
317 	/* Prepend skb with frame type */
318 	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
319 
320 	/* lock hcill state */
321 	spin_lock_irqsave(&ll->hcill_lock, flags);
322 
323 	/* act according to current state */
324 	switch (ll->hcill_state) {
325 	case HCILL_AWAKE:
326 		BT_DBG("device awake, sending normally");
327 		skb_queue_tail(&ll->txq, skb);
328 		break;
329 	case HCILL_ASLEEP:
330 		BT_DBG("device asleep, waking up and queueing packet");
331 		/* save packet for later */
332 		skb_queue_tail(&ll->tx_wait_q, skb);
333 		/* awake device */
334 		if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
335 			BT_ERR("cannot wake up device");
336 			break;
337 		}
338 		ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
339 		break;
340 	case HCILL_ASLEEP_TO_AWAKE:
341 		BT_DBG("device waking up, queueing packet");
342 		/* transient state; just keep packet for later */
343 		skb_queue_tail(&ll->tx_wait_q, skb);
344 		break;
345 	default:
346 		BT_ERR("illegal hcill state: %ld (losing packet)",
347 		       ll->hcill_state);
348 		kfree_skb(skb);
349 		break;
350 	}
351 
352 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
353 
354 	return 0;
355 }
356 
357 static int ll_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
358 {
359 	struct hci_uart *hu = hci_get_drvdata(hdev);
360 	struct ll_struct *ll = hu->priv;
361 
362 	switch (hci_skb_pkt_type(skb)) {
363 	case HCILL_GO_TO_SLEEP_IND:
364 		BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
365 		ll_device_want_to_sleep(hu);
366 		break;
367 	case HCILL_GO_TO_SLEEP_ACK:
368 		/* shouldn't happen */
369 		bt_dev_err(hdev, "received HCILL_GO_TO_SLEEP_ACK in state %ld",
370 			   ll->hcill_state);
371 		break;
372 	case HCILL_WAKE_UP_IND:
373 		BT_DBG("HCILL_WAKE_UP_IND packet");
374 		ll_device_want_to_wakeup(hu);
375 		break;
376 	case HCILL_WAKE_UP_ACK:
377 		BT_DBG("HCILL_WAKE_UP_ACK packet");
378 		ll_device_woke_up(hu);
379 		break;
380 	}
381 
382 	kfree_skb(skb);
383 	return 0;
384 }
385 
386 #define LL_RECV_SLEEP_IND \
387 	.type = HCILL_GO_TO_SLEEP_IND, \
388 	.hlen = 0, \
389 	.loff = 0, \
390 	.lsize = 0, \
391 	.maxlen = 0
392 
393 #define LL_RECV_SLEEP_ACK \
394 	.type = HCILL_GO_TO_SLEEP_ACK, \
395 	.hlen = 0, \
396 	.loff = 0, \
397 	.lsize = 0, \
398 	.maxlen = 0
399 
400 #define LL_RECV_WAKE_IND \
401 	.type = HCILL_WAKE_UP_IND, \
402 	.hlen = 0, \
403 	.loff = 0, \
404 	.lsize = 0, \
405 	.maxlen = 0
406 
407 #define LL_RECV_WAKE_ACK \
408 	.type = HCILL_WAKE_UP_ACK, \
409 	.hlen = 0, \
410 	.loff = 0, \
411 	.lsize = 0, \
412 	.maxlen = 0
413 
414 static const struct h4_recv_pkt ll_recv_pkts[] = {
415 	{ H4_RECV_ACL,       .recv = hci_recv_frame },
416 	{ H4_RECV_SCO,       .recv = hci_recv_frame },
417 	{ H4_RECV_EVENT,     .recv = hci_recv_frame },
418 	{ LL_RECV_SLEEP_IND, .recv = ll_recv_frame  },
419 	{ LL_RECV_SLEEP_ACK, .recv = ll_recv_frame  },
420 	{ LL_RECV_WAKE_IND,  .recv = ll_recv_frame  },
421 	{ LL_RECV_WAKE_ACK,  .recv = ll_recv_frame  },
422 };
423 
424 /* Recv data */
425 static int ll_recv(struct hci_uart *hu, const void *data, int count)
426 {
427 	struct ll_struct *ll = hu->priv;
428 
429 	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
430 		return -EUNATCH;
431 
432 	ll->rx_skb = h4_recv_buf(hu->hdev, ll->rx_skb, data, count,
433 				 ll_recv_pkts, ARRAY_SIZE(ll_recv_pkts));
434 	if (IS_ERR(ll->rx_skb)) {
435 		int err = PTR_ERR(ll->rx_skb);
436 		bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
437 		ll->rx_skb = NULL;
438 		return err;
439 	}
440 
441 	return count;
442 }
443 
444 static struct sk_buff *ll_dequeue(struct hci_uart *hu)
445 {
446 	struct ll_struct *ll = hu->priv;
447 
448 	return skb_dequeue(&ll->txq);
449 }
450 
451 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
452 static int read_local_version(struct hci_dev *hdev)
453 {
454 	int err = 0;
455 	unsigned short version = 0;
456 	struct sk_buff *skb;
457 	struct hci_rp_read_local_version *ver;
458 
459 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
460 			     HCI_INIT_TIMEOUT);
461 	if (IS_ERR(skb)) {
462 		bt_dev_err(hdev, "Reading TI version information failed (%ld)",
463 			   PTR_ERR(skb));
464 		return PTR_ERR(skb);
465 	}
466 	if (skb->len != sizeof(*ver)) {
467 		err = -EILSEQ;
468 		goto out;
469 	}
470 
471 	ver = (struct hci_rp_read_local_version *)skb->data;
472 	if (le16_to_cpu(ver->manufacturer) != 13) {
473 		err = -ENODEV;
474 		goto out;
475 	}
476 
477 	version = le16_to_cpu(ver->lmp_subver);
478 
479 out:
480 	if (err)
481 		bt_dev_err(hdev, "Failed to read TI version info: %d", err);
482 	kfree_skb(skb);
483 	return err ? err : version;
484 }
485 
486 static int send_command_from_firmware(struct ll_device *lldev,
487 				      struct hci_command *cmd)
488 {
489 	struct sk_buff *skb;
490 
491 	if (cmd->opcode == HCI_VS_UPDATE_UART_HCI_BAUDRATE) {
492 		/* ignore remote change
493 		 * baud rate HCI VS command
494 		 */
495 		bt_dev_warn(lldev->hu.hdev,
496 			    "change remote baud rate command in firmware");
497 		return 0;
498 	}
499 	if (cmd->prefix != 1)
500 		bt_dev_dbg(lldev->hu.hdev, "command type %d", cmd->prefix);
501 
502 	skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen,
503 			     &cmd->speed, HCI_INIT_TIMEOUT);
504 	if (IS_ERR(skb)) {
505 		bt_dev_err(lldev->hu.hdev, "send command failed");
506 		return PTR_ERR(skb);
507 	}
508 	kfree_skb(skb);
509 	return 0;
510 }
511 
512 /**
513  * download_firmware -
514  *	internal function which parses through the .bts firmware
515  *	script file intreprets SEND, DELAY actions only as of now
516  */
517 static int download_firmware(struct ll_device *lldev)
518 {
519 	unsigned short chip, min_ver, maj_ver;
520 	int version, err, len;
521 	unsigned char *ptr, *action_ptr;
522 	unsigned char bts_scr_name[40];	/* 40 char long bts scr name? */
523 	const struct firmware *fw;
524 	struct hci_command *cmd;
525 
526 	version = read_local_version(lldev->hu.hdev);
527 	if (version < 0)
528 		return version;
529 
530 	chip = (version & 0x7C00) >> 10;
531 	min_ver = (version & 0x007F);
532 	maj_ver = (version & 0x0380) >> 7;
533 	if (version & 0x8000)
534 		maj_ver |= 0x0008;
535 
536 	snprintf(bts_scr_name, sizeof(bts_scr_name),
537 		 "ti-connectivity/TIInit_%d.%d.%d.bts",
538 		 chip, maj_ver, min_ver);
539 
540 	err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
541 	if (err || !fw->data || !fw->size) {
542 		bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
543 			   err, bts_scr_name);
544 		return -EINVAL;
545 	}
546 	ptr = (void *)fw->data;
547 	len = fw->size;
548 	/* bts_header to remove out magic number and
549 	 * version
550 	 */
551 	ptr += sizeof(struct bts_header);
552 	len -= sizeof(struct bts_header);
553 
554 	while (len > 0 && ptr) {
555 		bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
556 			   ((struct bts_action *)ptr)->size,
557 			   ((struct bts_action *)ptr)->type);
558 
559 		action_ptr = &(((struct bts_action *)ptr)->data[0]);
560 
561 		switch (((struct bts_action *)ptr)->type) {
562 		case ACTION_SEND_COMMAND:	/* action send */
563 			bt_dev_dbg(lldev->hu.hdev, "S");
564 			cmd = (struct hci_command *)action_ptr;
565 			err = send_command_from_firmware(lldev, cmd);
566 			if (err)
567 				goto out_rel_fw;
568 			break;
569 		case ACTION_WAIT_EVENT:  /* wait */
570 			/* no need to wait as command was synchronous */
571 			bt_dev_dbg(lldev->hu.hdev, "W");
572 			break;
573 		case ACTION_DELAY:	/* sleep */
574 			bt_dev_info(lldev->hu.hdev, "sleep command in scr");
575 			msleep(((struct bts_action_delay *)action_ptr)->msec);
576 			break;
577 		}
578 		len -= (sizeof(struct bts_action) +
579 			((struct bts_action *)ptr)->size);
580 		ptr += sizeof(struct bts_action) +
581 			((struct bts_action *)ptr)->size;
582 	}
583 
584 out_rel_fw:
585 	/* fw download complete */
586 	release_firmware(fw);
587 	return err;
588 }
589 
590 static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
591 {
592 	bdaddr_t bdaddr_swapped;
593 	struct sk_buff *skb;
594 
595 	/* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
596 	 * address to be MSB first, but bdaddr_t has the convention of being
597 	 * LSB first.
598 	 */
599 	baswap(&bdaddr_swapped, bdaddr);
600 	skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
601 			     &bdaddr_swapped, HCI_INIT_TIMEOUT);
602 	if (!IS_ERR(skb))
603 		kfree_skb(skb);
604 
605 	return PTR_ERR_OR_ZERO(skb);
606 }
607 
608 static int ll_setup(struct hci_uart *hu)
609 {
610 	int err, retry = 3;
611 	struct ll_device *lldev;
612 	struct serdev_device *serdev = hu->serdev;
613 	u32 speed;
614 
615 	if (!serdev)
616 		return 0;
617 
618 	lldev = serdev_device_get_drvdata(serdev);
619 
620 	hu->hdev->set_bdaddr = ll_set_bdaddr;
621 
622 	serdev_device_set_flow_control(serdev, true);
623 
624 	do {
625 		/* Reset the Bluetooth device */
626 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
627 		msleep(5);
628 		gpiod_set_value_cansleep(lldev->enable_gpio, 1);
629 		err = serdev_device_wait_for_cts(serdev, true, 200);
630 		if (err) {
631 			bt_dev_err(hu->hdev, "Failed to get CTS");
632 			return err;
633 		}
634 
635 		err = download_firmware(lldev);
636 		if (!err)
637 			break;
638 
639 		/* Toggle BT_EN and retry */
640 		bt_dev_err(hu->hdev, "download firmware failed, retrying...");
641 	} while (retry--);
642 
643 	if (err)
644 		return err;
645 
646 	/* Set BD address if one was specified at probe */
647 	if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
648 		/* This means that there was an error getting the BD address
649 		 * during probe, so mark the device as having a bad address.
650 		 */
651 		set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
652 	} else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
653 		err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
654 		if (err)
655 			set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
656 	}
657 
658 	/* Operational speed if any */
659 	if (hu->oper_speed)
660 		speed = hu->oper_speed;
661 	else if (hu->proto->oper_speed)
662 		speed = hu->proto->oper_speed;
663 	else
664 		speed = 0;
665 
666 	if (speed) {
667 		__le32 speed_le = cpu_to_le32(speed);
668 		struct sk_buff *skb;
669 
670 		skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
671 				     sizeof(speed_le), &speed_le,
672 				     HCI_INIT_TIMEOUT);
673 		if (!IS_ERR(skb)) {
674 			kfree_skb(skb);
675 			serdev_device_set_baudrate(serdev, speed);
676 		}
677 	}
678 
679 	return 0;
680 }
681 
682 static const struct hci_uart_proto llp;
683 
684 static int hci_ti_probe(struct serdev_device *serdev)
685 {
686 	struct hci_uart *hu;
687 	struct ll_device *lldev;
688 	struct nvmem_cell *bdaddr_cell;
689 	u32 max_speed = 3000000;
690 
691 	lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
692 	if (!lldev)
693 		return -ENOMEM;
694 	hu = &lldev->hu;
695 
696 	serdev_device_set_drvdata(serdev, lldev);
697 	lldev->serdev = hu->serdev = serdev;
698 
699 	lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev,
700 						     "enable",
701 						     GPIOD_OUT_LOW);
702 	if (IS_ERR(lldev->enable_gpio))
703 		return PTR_ERR(lldev->enable_gpio);
704 
705 	lldev->ext_clk = devm_clk_get(&serdev->dev, "ext_clock");
706 	if (IS_ERR(lldev->ext_clk) && PTR_ERR(lldev->ext_clk) != -ENOENT)
707 		return PTR_ERR(lldev->ext_clk);
708 
709 	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
710 	hci_uart_set_speeds(hu, 115200, max_speed);
711 
712 	/* optional BD address from nvram */
713 	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
714 	if (IS_ERR(bdaddr_cell)) {
715 		int err = PTR_ERR(bdaddr_cell);
716 
717 		if (err == -EPROBE_DEFER)
718 			return err;
719 
720 		/* ENOENT means there is no matching nvmem cell and ENOSYS
721 		 * means that nvmem is not enabled in the kernel configuration.
722 		 */
723 		if (err != -ENOENT && err != -ENOSYS) {
724 			/* If there was some other error, give userspace a
725 			 * chance to fix the problem instead of failing to load
726 			 * the driver. Using BDADDR_NONE as a flag that is
727 			 * tested later in the setup function.
728 			 */
729 			dev_warn(&serdev->dev,
730 				 "Failed to get \"bd-address\" nvmem cell (%d)\n",
731 				 err);
732 			bacpy(&lldev->bdaddr, BDADDR_NONE);
733 		}
734 	} else {
735 		bdaddr_t *bdaddr;
736 		size_t len;
737 
738 		bdaddr = nvmem_cell_read(bdaddr_cell, &len);
739 		nvmem_cell_put(bdaddr_cell);
740 		if (IS_ERR(bdaddr)) {
741 			dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
742 			return PTR_ERR(bdaddr);
743 		}
744 		if (len != sizeof(bdaddr_t)) {
745 			dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
746 			kfree(bdaddr);
747 			return -EINVAL;
748 		}
749 
750 		/* As per the device tree bindings, the value from nvmem is
751 		 * expected to be MSB first, but in the kernel it is expected
752 		 * that bdaddr_t is LSB first.
753 		 */
754 		baswap(&lldev->bdaddr, bdaddr);
755 		kfree(bdaddr);
756 	}
757 
758 	return hci_uart_register_device(hu, &llp);
759 }
760 
761 static void hci_ti_remove(struct serdev_device *serdev)
762 {
763 	struct ll_device *lldev = serdev_device_get_drvdata(serdev);
764 
765 	hci_uart_unregister_device(&lldev->hu);
766 }
767 
768 static const struct of_device_id hci_ti_of_match[] = {
769 	{ .compatible = "ti,cc2560" },
770 	{ .compatible = "ti,wl1271-st" },
771 	{ .compatible = "ti,wl1273-st" },
772 	{ .compatible = "ti,wl1281-st" },
773 	{ .compatible = "ti,wl1283-st" },
774 	{ .compatible = "ti,wl1285-st" },
775 	{ .compatible = "ti,wl1801-st" },
776 	{ .compatible = "ti,wl1805-st" },
777 	{ .compatible = "ti,wl1807-st" },
778 	{ .compatible = "ti,wl1831-st" },
779 	{ .compatible = "ti,wl1835-st" },
780 	{ .compatible = "ti,wl1837-st" },
781 	{},
782 };
783 MODULE_DEVICE_TABLE(of, hci_ti_of_match);
784 
785 static struct serdev_device_driver hci_ti_drv = {
786 	.driver		= {
787 		.name	= "hci-ti",
788 		.of_match_table = of_match_ptr(hci_ti_of_match),
789 	},
790 	.probe	= hci_ti_probe,
791 	.remove	= hci_ti_remove,
792 };
793 #else
794 #define ll_setup NULL
795 #endif
796 
797 static const struct hci_uart_proto llp = {
798 	.id		= HCI_UART_LL,
799 	.name		= "LL",
800 	.setup		= ll_setup,
801 	.open		= ll_open,
802 	.close		= ll_close,
803 	.recv		= ll_recv,
804 	.enqueue	= ll_enqueue,
805 	.dequeue	= ll_dequeue,
806 	.flush		= ll_flush,
807 };
808 
809 int __init ll_init(void)
810 {
811 	serdev_device_driver_register(&hci_ti_drv);
812 
813 	return hci_uart_register_proto(&llp);
814 }
815 
816 int __exit ll_deinit(void)
817 {
818 	serdev_device_driver_unregister(&hci_ti_drv);
819 
820 	return hci_uart_unregister_proto(&llp);
821 }
822