xref: /openbmc/linux/drivers/bluetooth/hci_ll.c (revision addee42a)
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 states */
71 enum hcill_states_e {
72 	HCILL_ASLEEP,
73 	HCILL_ASLEEP_TO_AWAKE,
74 	HCILL_AWAKE,
75 	HCILL_AWAKE_TO_ASLEEP
76 };
77 
78 struct ll_device {
79 	struct hci_uart hu;
80 	struct serdev_device *serdev;
81 	struct gpio_desc *enable_gpio;
82 	struct clk *ext_clk;
83 	bdaddr_t bdaddr;
84 };
85 
86 struct ll_struct {
87 	struct sk_buff *rx_skb;
88 	struct sk_buff_head txq;
89 	spinlock_t hcill_lock;		/* HCILL state lock	*/
90 	unsigned long hcill_state;	/* HCILL power state	*/
91 	struct sk_buff_head tx_wait_q;	/* HCILL wait queue	*/
92 };
93 
94 /*
95  * Builds and sends an HCILL command packet.
96  * These are very simple packets with only 1 cmd byte
97  */
98 static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
99 {
100 	int err = 0;
101 	struct sk_buff *skb = NULL;
102 	struct ll_struct *ll = hu->priv;
103 
104 	BT_DBG("hu %p cmd 0x%x", hu, cmd);
105 
106 	/* allocate packet */
107 	skb = bt_skb_alloc(1, GFP_ATOMIC);
108 	if (!skb) {
109 		BT_ERR("cannot allocate memory for HCILL packet");
110 		err = -ENOMEM;
111 		goto out;
112 	}
113 
114 	/* prepare packet */
115 	skb_put_u8(skb, cmd);
116 
117 	/* send packet */
118 	skb_queue_tail(&ll->txq, skb);
119 out:
120 	return err;
121 }
122 
123 /* Initialize protocol */
124 static int ll_open(struct hci_uart *hu)
125 {
126 	struct ll_struct *ll;
127 
128 	BT_DBG("hu %p", hu);
129 
130 	ll = kzalloc(sizeof(*ll), GFP_KERNEL);
131 	if (!ll)
132 		return -ENOMEM;
133 
134 	skb_queue_head_init(&ll->txq);
135 	skb_queue_head_init(&ll->tx_wait_q);
136 	spin_lock_init(&ll->hcill_lock);
137 
138 	ll->hcill_state = HCILL_AWAKE;
139 
140 	hu->priv = ll;
141 
142 	if (hu->serdev) {
143 		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
144 		serdev_device_open(hu->serdev);
145 		if (!IS_ERR(lldev->ext_clk))
146 			clk_prepare_enable(lldev->ext_clk);
147 	}
148 
149 	return 0;
150 }
151 
152 /* Flush protocol data */
153 static int ll_flush(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 	return 0;
163 }
164 
165 /* Close protocol */
166 static int ll_close(struct hci_uart *hu)
167 {
168 	struct ll_struct *ll = hu->priv;
169 
170 	BT_DBG("hu %p", hu);
171 
172 	skb_queue_purge(&ll->tx_wait_q);
173 	skb_queue_purge(&ll->txq);
174 
175 	kfree_skb(ll->rx_skb);
176 
177 	if (hu->serdev) {
178 		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
179 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
180 
181 		clk_disable_unprepare(lldev->ext_clk);
182 
183 		serdev_device_close(hu->serdev);
184 	}
185 
186 	hu->priv = NULL;
187 
188 	kfree(ll);
189 
190 	return 0;
191 }
192 
193 /*
194  * internal function, which does common work of the device wake up process:
195  * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
196  * 2. changes internal state to HCILL_AWAKE.
197  * Note: assumes that hcill_lock spinlock is taken,
198  * shouldn't be called otherwise!
199  */
200 static void __ll_do_awake(struct ll_struct *ll)
201 {
202 	struct sk_buff *skb = NULL;
203 
204 	while ((skb = skb_dequeue(&ll->tx_wait_q)))
205 		skb_queue_tail(&ll->txq, skb);
206 
207 	ll->hcill_state = HCILL_AWAKE;
208 }
209 
210 /*
211  * Called upon a wake-up-indication from the device
212  */
213 static void ll_device_want_to_wakeup(struct hci_uart *hu)
214 {
215 	unsigned long flags;
216 	struct ll_struct *ll = hu->priv;
217 
218 	BT_DBG("hu %p", hu);
219 
220 	/* lock hcill state */
221 	spin_lock_irqsave(&ll->hcill_lock, flags);
222 
223 	switch (ll->hcill_state) {
224 	case HCILL_ASLEEP_TO_AWAKE:
225 		/*
226 		 * This state means that both the host and the BRF chip
227 		 * have simultaneously sent a wake-up-indication packet.
228 		 * Traditionally, in this case, receiving a wake-up-indication
229 		 * was enough and an additional wake-up-ack wasn't needed.
230 		 * This has changed with the BRF6350, which does require an
231 		 * explicit wake-up-ack. Other BRF versions, which do not
232 		 * require an explicit ack here, do accept it, thus it is
233 		 * perfectly safe to always send one.
234 		 */
235 		BT_DBG("dual wake-up-indication");
236 		/* fall through */
237 	case HCILL_ASLEEP:
238 		/* acknowledge device wake up */
239 		if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
240 			BT_ERR("cannot acknowledge device wake up");
241 			goto out;
242 		}
243 		break;
244 	default:
245 		/* any other state is illegal */
246 		BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
247 		break;
248 	}
249 
250 	/* send pending packets and change state to HCILL_AWAKE */
251 	__ll_do_awake(ll);
252 
253 out:
254 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
255 
256 	/* actually send the packets */
257 	hci_uart_tx_wakeup(hu);
258 }
259 
260 /*
261  * Called upon a sleep-indication from the device
262  */
263 static void ll_device_want_to_sleep(struct hci_uart *hu)
264 {
265 	unsigned long flags;
266 	struct ll_struct *ll = hu->priv;
267 
268 	BT_DBG("hu %p", hu);
269 
270 	/* lock hcill state */
271 	spin_lock_irqsave(&ll->hcill_lock, flags);
272 
273 	/* sanity check */
274 	if (ll->hcill_state != HCILL_AWAKE)
275 		BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
276 
277 	/* acknowledge device sleep */
278 	if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
279 		BT_ERR("cannot acknowledge device sleep");
280 		goto out;
281 	}
282 
283 	/* update state */
284 	ll->hcill_state = HCILL_ASLEEP;
285 
286 out:
287 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
288 
289 	/* actually send the sleep ack packet */
290 	hci_uart_tx_wakeup(hu);
291 }
292 
293 /*
294  * Called upon wake-up-acknowledgement from the device
295  */
296 static void ll_device_woke_up(struct hci_uart *hu)
297 {
298 	unsigned long flags;
299 	struct ll_struct *ll = hu->priv;
300 
301 	BT_DBG("hu %p", hu);
302 
303 	/* lock hcill state */
304 	spin_lock_irqsave(&ll->hcill_lock, flags);
305 
306 	/* sanity check */
307 	if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
308 		BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
309 
310 	/* send pending packets and change state to HCILL_AWAKE */
311 	__ll_do_awake(ll);
312 
313 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
314 
315 	/* actually send the packets */
316 	hci_uart_tx_wakeup(hu);
317 }
318 
319 /* Enqueue frame for transmittion (padding, crc, etc) */
320 /* may be called from two simultaneous tasklets */
321 static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
322 {
323 	unsigned long flags = 0;
324 	struct ll_struct *ll = hu->priv;
325 
326 	BT_DBG("hu %p skb %p", hu, skb);
327 
328 	/* Prepend skb with frame type */
329 	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
330 
331 	/* lock hcill state */
332 	spin_lock_irqsave(&ll->hcill_lock, flags);
333 
334 	/* act according to current state */
335 	switch (ll->hcill_state) {
336 	case HCILL_AWAKE:
337 		BT_DBG("device awake, sending normally");
338 		skb_queue_tail(&ll->txq, skb);
339 		break;
340 	case HCILL_ASLEEP:
341 		BT_DBG("device asleep, waking up and queueing packet");
342 		/* save packet for later */
343 		skb_queue_tail(&ll->tx_wait_q, skb);
344 		/* awake device */
345 		if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
346 			BT_ERR("cannot wake up device");
347 			break;
348 		}
349 		ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
350 		break;
351 	case HCILL_ASLEEP_TO_AWAKE:
352 		BT_DBG("device waking up, queueing packet");
353 		/* transient state; just keep packet for later */
354 		skb_queue_tail(&ll->tx_wait_q, skb);
355 		break;
356 	default:
357 		BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
358 		kfree_skb(skb);
359 		break;
360 	}
361 
362 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
363 
364 	return 0;
365 }
366 
367 static int ll_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
368 {
369 	struct hci_uart *hu = hci_get_drvdata(hdev);
370 	struct ll_struct *ll = hu->priv;
371 
372 	switch (hci_skb_pkt_type(skb)) {
373 	case HCILL_GO_TO_SLEEP_IND:
374 		BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
375 		ll_device_want_to_sleep(hu);
376 		break;
377 	case HCILL_GO_TO_SLEEP_ACK:
378 		/* shouldn't happen */
379 		bt_dev_err(hdev, "received HCILL_GO_TO_SLEEP_ACK in state %ld",
380 			   ll->hcill_state);
381 		break;
382 	case HCILL_WAKE_UP_IND:
383 		BT_DBG("HCILL_WAKE_UP_IND packet");
384 		ll_device_want_to_wakeup(hu);
385 		break;
386 	case HCILL_WAKE_UP_ACK:
387 		BT_DBG("HCILL_WAKE_UP_ACK packet");
388 		ll_device_woke_up(hu);
389 		break;
390 	}
391 
392 	kfree_skb(skb);
393 	return 0;
394 }
395 
396 #define LL_RECV_SLEEP_IND \
397 	.type = HCILL_GO_TO_SLEEP_IND, \
398 	.hlen = 0, \
399 	.loff = 0, \
400 	.lsize = 0, \
401 	.maxlen = 0
402 
403 #define LL_RECV_SLEEP_ACK \
404 	.type = HCILL_GO_TO_SLEEP_ACK, \
405 	.hlen = 0, \
406 	.loff = 0, \
407 	.lsize = 0, \
408 	.maxlen = 0
409 
410 #define LL_RECV_WAKE_IND \
411 	.type = HCILL_WAKE_UP_IND, \
412 	.hlen = 0, \
413 	.loff = 0, \
414 	.lsize = 0, \
415 	.maxlen = 0
416 
417 #define LL_RECV_WAKE_ACK \
418 	.type = HCILL_WAKE_UP_ACK, \
419 	.hlen = 0, \
420 	.loff = 0, \
421 	.lsize = 0, \
422 	.maxlen = 0
423 
424 static const struct h4_recv_pkt ll_recv_pkts[] = {
425 	{ H4_RECV_ACL,       .recv = hci_recv_frame },
426 	{ H4_RECV_SCO,       .recv = hci_recv_frame },
427 	{ H4_RECV_EVENT,     .recv = hci_recv_frame },
428 	{ LL_RECV_SLEEP_IND, .recv = ll_recv_frame  },
429 	{ LL_RECV_SLEEP_ACK, .recv = ll_recv_frame  },
430 	{ LL_RECV_WAKE_IND,  .recv = ll_recv_frame  },
431 	{ LL_RECV_WAKE_ACK,  .recv = ll_recv_frame  },
432 };
433 
434 /* Recv data */
435 static int ll_recv(struct hci_uart *hu, const void *data, int count)
436 {
437 	struct ll_struct *ll = hu->priv;
438 
439 	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
440 		return -EUNATCH;
441 
442 	ll->rx_skb = h4_recv_buf(hu->hdev, ll->rx_skb, data, count,
443 				 ll_recv_pkts, ARRAY_SIZE(ll_recv_pkts));
444 	if (IS_ERR(ll->rx_skb)) {
445 		int err = PTR_ERR(ll->rx_skb);
446 		bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
447 		ll->rx_skb = NULL;
448 		return err;
449 	}
450 
451 	return count;
452 }
453 
454 static struct sk_buff *ll_dequeue(struct hci_uart *hu)
455 {
456 	struct ll_struct *ll = hu->priv;
457 	return skb_dequeue(&ll->txq);
458 }
459 
460 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
461 static int read_local_version(struct hci_dev *hdev)
462 {
463 	int err = 0;
464 	unsigned short version = 0;
465 	struct sk_buff *skb;
466 	struct hci_rp_read_local_version *ver;
467 
468 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL, HCI_INIT_TIMEOUT);
469 	if (IS_ERR(skb)) {
470 		bt_dev_err(hdev, "Reading TI version information failed (%ld)",
471 			   PTR_ERR(skb));
472 		return PTR_ERR(skb);
473 	}
474 	if (skb->len != sizeof(*ver)) {
475 		err = -EILSEQ;
476 		goto out;
477 	}
478 
479 	ver = (struct hci_rp_read_local_version *)skb->data;
480 	if (le16_to_cpu(ver->manufacturer) != 13) {
481 		err = -ENODEV;
482 		goto out;
483 	}
484 
485 	version = le16_to_cpu(ver->lmp_subver);
486 
487 out:
488 	if (err) bt_dev_err(hdev, "Failed to read TI version info: %d", err);
489 	kfree_skb(skb);
490 	return err ? err : version;
491 }
492 
493 /**
494  * download_firmware -
495  *	internal function which parses through the .bts firmware
496  *	script file intreprets SEND, DELAY actions only as of now
497  */
498 static int download_firmware(struct ll_device *lldev)
499 {
500 	unsigned short chip, min_ver, maj_ver;
501 	int version, err, len;
502 	unsigned char *ptr, *action_ptr;
503 	unsigned char bts_scr_name[40];	/* 40 char long bts scr name? */
504 	const struct firmware *fw;
505 	struct sk_buff *skb;
506 	struct hci_command *cmd;
507 
508 	version = read_local_version(lldev->hu.hdev);
509 	if (version < 0)
510 		return version;
511 
512 	chip = (version & 0x7C00) >> 10;
513 	min_ver = (version & 0x007F);
514 	maj_ver = (version & 0x0380) >> 7;
515 	if (version & 0x8000)
516 		maj_ver |= 0x0008;
517 
518 	snprintf(bts_scr_name, sizeof(bts_scr_name),
519 		 "ti-connectivity/TIInit_%d.%d.%d.bts",
520 		 chip, maj_ver, min_ver);
521 
522 	err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
523 	if (err || !fw->data || !fw->size) {
524 		bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
525 			   err, bts_scr_name);
526 		return -EINVAL;
527 	}
528 	ptr = (void *)fw->data;
529 	len = fw->size;
530 	/* bts_header to remove out magic number and
531 	 * version
532 	 */
533 	ptr += sizeof(struct bts_header);
534 	len -= sizeof(struct bts_header);
535 
536 	while (len > 0 && ptr) {
537 		bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
538 			   ((struct bts_action *)ptr)->size,
539 			   ((struct bts_action *)ptr)->type);
540 
541 		action_ptr = &(((struct bts_action *)ptr)->data[0]);
542 
543 		switch (((struct bts_action *)ptr)->type) {
544 		case ACTION_SEND_COMMAND:	/* action send */
545 			bt_dev_dbg(lldev->hu.hdev, "S");
546 			cmd = (struct hci_command *)action_ptr;
547 			if (cmd->opcode == HCI_VS_UPDATE_UART_HCI_BAUDRATE) {
548 				/* ignore remote change
549 				 * baud rate HCI VS command
550 				 */
551 				bt_dev_warn(lldev->hu.hdev, "change remote baud rate command in firmware");
552 				break;
553 			}
554 			if (cmd->prefix != 1)
555 				bt_dev_dbg(lldev->hu.hdev, "command type %d", cmd->prefix);
556 
557 			skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen, &cmd->speed, HCI_INIT_TIMEOUT);
558 			if (IS_ERR(skb)) {
559 				bt_dev_err(lldev->hu.hdev, "send command failed");
560 				err = PTR_ERR(skb);
561 				goto out_rel_fw;
562 			}
563 			kfree_skb(skb);
564 			break;
565 		case ACTION_WAIT_EVENT:  /* wait */
566 			/* no need to wait as command was synchronous */
567 			bt_dev_dbg(lldev->hu.hdev, "W");
568 			break;
569 		case ACTION_DELAY:	/* sleep */
570 			bt_dev_info(lldev->hu.hdev, "sleep command in scr");
571 			msleep(((struct bts_action_delay *)action_ptr)->msec);
572 			break;
573 		}
574 		len -= (sizeof(struct bts_action) +
575 			((struct bts_action *)ptr)->size);
576 		ptr += sizeof(struct bts_action) +
577 			((struct bts_action *)ptr)->size;
578 	}
579 
580 out_rel_fw:
581 	/* fw download complete */
582 	release_firmware(fw);
583 	return err;
584 }
585 
586 static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
587 {
588 	bdaddr_t bdaddr_swapped;
589 	struct sk_buff *skb;
590 
591 	/* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
592 	 * address to be MSB first, but bdaddr_t has the convention of being
593 	 * LSB first.
594 	 */
595 	baswap(&bdaddr_swapped, bdaddr);
596 	skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
597 			     &bdaddr_swapped, HCI_INIT_TIMEOUT);
598 	if (!IS_ERR(skb))
599 		kfree_skb(skb);
600 
601 	return PTR_ERR_OR_ZERO(skb);
602 }
603 
604 static int ll_setup(struct hci_uart *hu)
605 {
606 	int err, retry = 3;
607 	struct ll_device *lldev;
608 	struct serdev_device *serdev = hu->serdev;
609 	u32 speed;
610 
611 	if (!serdev)
612 		return 0;
613 
614 	lldev = serdev_device_get_drvdata(serdev);
615 
616 	hu->hdev->set_bdaddr = ll_set_bdaddr;
617 
618 	serdev_device_set_flow_control(serdev, true);
619 
620 	do {
621 		/* Reset the Bluetooth device */
622 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
623 		msleep(5);
624 		gpiod_set_value_cansleep(lldev->enable_gpio, 1);
625 		err = serdev_device_wait_for_cts(serdev, true, 200);
626 		if (err) {
627 			bt_dev_err(hu->hdev, "Failed to get CTS");
628 			return err;
629 		}
630 
631 		err = download_firmware(lldev);
632 		if (!err)
633 			break;
634 
635 		/* Toggle BT_EN and retry */
636 		bt_dev_err(hu->hdev, "download firmware failed, retrying...");
637 	} while (retry--);
638 
639 	if (err)
640 		return err;
641 
642 	/* Set BD address if one was specified at probe */
643 	if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
644 		/* This means that there was an error getting the BD address
645 		 * during probe, so mark the device as having a bad address.
646 		 */
647 		set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
648 	} else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
649 		err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
650 		if (err)
651 			set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
652 	}
653 
654 	/* Operational speed if any */
655 	if (hu->oper_speed)
656 		speed = hu->oper_speed;
657 	else if (hu->proto->oper_speed)
658 		speed = hu->proto->oper_speed;
659 	else
660 		speed = 0;
661 
662 	if (speed) {
663 		__le32 speed_le = cpu_to_le32(speed);
664 		struct sk_buff *skb;
665 
666 		skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
667 				     sizeof(speed_le), &speed_le,
668 				     HCI_INIT_TIMEOUT);
669 		if (!IS_ERR(skb)) {
670 			kfree_skb(skb);
671 			serdev_device_set_baudrate(serdev, speed);
672 		}
673 	}
674 
675 	return 0;
676 }
677 
678 static const struct hci_uart_proto llp;
679 
680 static int hci_ti_probe(struct serdev_device *serdev)
681 {
682 	struct hci_uart *hu;
683 	struct ll_device *lldev;
684 	struct nvmem_cell *bdaddr_cell;
685 	u32 max_speed = 3000000;
686 
687 	lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
688 	if (!lldev)
689 		return -ENOMEM;
690 	hu = &lldev->hu;
691 
692 	serdev_device_set_drvdata(serdev, lldev);
693 	lldev->serdev = hu->serdev = serdev;
694 
695 	lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev, "enable", GPIOD_OUT_LOW);
696 	if (IS_ERR(lldev->enable_gpio))
697 		return PTR_ERR(lldev->enable_gpio);
698 
699 	lldev->ext_clk = devm_clk_get(&serdev->dev, "ext_clock");
700 	if (IS_ERR(lldev->ext_clk) && PTR_ERR(lldev->ext_clk) != -ENOENT)
701 		return PTR_ERR(lldev->ext_clk);
702 
703 	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
704 	hci_uart_set_speeds(hu, 115200, max_speed);
705 
706 	/* optional BD address from nvram */
707 	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
708 	if (IS_ERR(bdaddr_cell)) {
709 		int err = PTR_ERR(bdaddr_cell);
710 
711 		if (err == -EPROBE_DEFER)
712 			return err;
713 
714 		/* ENOENT means there is no matching nvmem cell and ENOSYS
715 		 * means that nvmem is not enabled in the kernel configuration.
716 		 */
717 		if (err != -ENOENT && err != -ENOSYS) {
718 			/* If there was some other error, give userspace a
719 			 * chance to fix the problem instead of failing to load
720 			 * the driver. Using BDADDR_NONE as a flag that is
721 			 * tested later in the setup function.
722 			 */
723 			dev_warn(&serdev->dev,
724 				 "Failed to get \"bd-address\" nvmem cell (%d)\n",
725 				 err);
726 			bacpy(&lldev->bdaddr, BDADDR_NONE);
727 		}
728 	} else {
729 		bdaddr_t *bdaddr;
730 		size_t len;
731 
732 		bdaddr = nvmem_cell_read(bdaddr_cell, &len);
733 		nvmem_cell_put(bdaddr_cell);
734 		if (IS_ERR(bdaddr)) {
735 			dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
736 			return PTR_ERR(bdaddr);
737 		}
738 		if (len != sizeof(bdaddr_t)) {
739 			dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
740 			kfree(bdaddr);
741 			return -EINVAL;
742 		}
743 
744 		/* As per the device tree bindings, the value from nvmem is
745 		 * expected to be MSB first, but in the kernel it is expected
746 		 * that bdaddr_t is LSB first.
747 		 */
748 		baswap(&lldev->bdaddr, bdaddr);
749 		kfree(bdaddr);
750 	}
751 
752 	return hci_uart_register_device(hu, &llp);
753 }
754 
755 static void hci_ti_remove(struct serdev_device *serdev)
756 {
757 	struct ll_device *lldev = serdev_device_get_drvdata(serdev);
758 
759 	hci_uart_unregister_device(&lldev->hu);
760 }
761 
762 static const struct of_device_id hci_ti_of_match[] = {
763 	{ .compatible = "ti,cc2560" },
764 	{ .compatible = "ti,wl1271-st" },
765 	{ .compatible = "ti,wl1273-st" },
766 	{ .compatible = "ti,wl1281-st" },
767 	{ .compatible = "ti,wl1283-st" },
768 	{ .compatible = "ti,wl1285-st" },
769 	{ .compatible = "ti,wl1801-st" },
770 	{ .compatible = "ti,wl1805-st" },
771 	{ .compatible = "ti,wl1807-st" },
772 	{ .compatible = "ti,wl1831-st" },
773 	{ .compatible = "ti,wl1835-st" },
774 	{ .compatible = "ti,wl1837-st" },
775 	{},
776 };
777 MODULE_DEVICE_TABLE(of, hci_ti_of_match);
778 
779 static struct serdev_device_driver hci_ti_drv = {
780 	.driver		= {
781 		.name	= "hci-ti",
782 		.of_match_table = of_match_ptr(hci_ti_of_match),
783 	},
784 	.probe	= hci_ti_probe,
785 	.remove	= hci_ti_remove,
786 };
787 #else
788 #define ll_setup NULL
789 #endif
790 
791 static const struct hci_uart_proto llp = {
792 	.id		= HCI_UART_LL,
793 	.name		= "LL",
794 	.setup		= ll_setup,
795 	.open		= ll_open,
796 	.close		= ll_close,
797 	.recv		= ll_recv,
798 	.enqueue	= ll_enqueue,
799 	.dequeue	= ll_dequeue,
800 	.flush		= ll_flush,
801 };
802 
803 int __init ll_init(void)
804 {
805 	serdev_device_driver_register(&hci_ti_drv);
806 
807 	return hci_uart_register_proto(&llp);
808 }
809 
810 int __exit ll_deinit(void)
811 {
812 	serdev_device_driver_unregister(&hci_ti_drv);
813 
814 	return hci_uart_unregister_proto(&llp);
815 }
816