xref: /openbmc/linux/drivers/bluetooth/hci_ll.c (revision 22d55f02)
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 		if (!IS_ERR(lldev->ext_clk))
132 			clk_prepare_enable(lldev->ext_clk);
133 	}
134 
135 	return 0;
136 }
137 
138 /* Flush protocol data */
139 static int ll_flush(struct hci_uart *hu)
140 {
141 	struct ll_struct *ll = hu->priv;
142 
143 	BT_DBG("hu %p", hu);
144 
145 	skb_queue_purge(&ll->tx_wait_q);
146 	skb_queue_purge(&ll->txq);
147 
148 	return 0;
149 }
150 
151 /* Close protocol */
152 static int ll_close(struct hci_uart *hu)
153 {
154 	struct ll_struct *ll = hu->priv;
155 
156 	BT_DBG("hu %p", hu);
157 
158 	skb_queue_purge(&ll->tx_wait_q);
159 	skb_queue_purge(&ll->txq);
160 
161 	kfree_skb(ll->rx_skb);
162 
163 	if (hu->serdev) {
164 		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
165 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
166 
167 		clk_disable_unprepare(lldev->ext_clk);
168 	}
169 
170 	hu->priv = NULL;
171 
172 	kfree(ll);
173 
174 	return 0;
175 }
176 
177 /*
178  * internal function, which does common work of the device wake up process:
179  * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
180  * 2. changes internal state to HCILL_AWAKE.
181  * Note: assumes that hcill_lock spinlock is taken,
182  * shouldn't be called otherwise!
183  */
184 static void __ll_do_awake(struct ll_struct *ll)
185 {
186 	struct sk_buff *skb = NULL;
187 
188 	while ((skb = skb_dequeue(&ll->tx_wait_q)))
189 		skb_queue_tail(&ll->txq, skb);
190 
191 	ll->hcill_state = HCILL_AWAKE;
192 }
193 
194 /*
195  * Called upon a wake-up-indication from the device
196  */
197 static void ll_device_want_to_wakeup(struct hci_uart *hu)
198 {
199 	unsigned long flags;
200 	struct ll_struct *ll = hu->priv;
201 
202 	BT_DBG("hu %p", hu);
203 
204 	/* lock hcill state */
205 	spin_lock_irqsave(&ll->hcill_lock, flags);
206 
207 	switch (ll->hcill_state) {
208 	case HCILL_ASLEEP_TO_AWAKE:
209 		/*
210 		 * This state means that both the host and the BRF chip
211 		 * have simultaneously sent a wake-up-indication packet.
212 		 * Traditionally, in this case, receiving a wake-up-indication
213 		 * was enough and an additional wake-up-ack wasn't needed.
214 		 * This has changed with the BRF6350, which does require an
215 		 * explicit wake-up-ack. Other BRF versions, which do not
216 		 * require an explicit ack here, do accept it, thus it is
217 		 * perfectly safe to always send one.
218 		 */
219 		BT_DBG("dual wake-up-indication");
220 		/* fall through */
221 	case HCILL_ASLEEP:
222 		/* acknowledge device wake up */
223 		if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
224 			BT_ERR("cannot acknowledge device wake up");
225 			goto out;
226 		}
227 		break;
228 	default:
229 		/* any other state is illegal */
230 		BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
231 		break;
232 	}
233 
234 	/* send pending packets and change state to HCILL_AWAKE */
235 	__ll_do_awake(ll);
236 
237 out:
238 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
239 
240 	/* actually send the packets */
241 	hci_uart_tx_wakeup(hu);
242 }
243 
244 /*
245  * Called upon a sleep-indication from the device
246  */
247 static void ll_device_want_to_sleep(struct hci_uart *hu)
248 {
249 	unsigned long flags;
250 	struct ll_struct *ll = hu->priv;
251 
252 	BT_DBG("hu %p", hu);
253 
254 	/* lock hcill state */
255 	spin_lock_irqsave(&ll->hcill_lock, flags);
256 
257 	/* sanity check */
258 	if (ll->hcill_state != HCILL_AWAKE)
259 		BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
260 
261 	/* acknowledge device sleep */
262 	if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
263 		BT_ERR("cannot acknowledge device sleep");
264 		goto out;
265 	}
266 
267 	/* update state */
268 	ll->hcill_state = HCILL_ASLEEP;
269 
270 out:
271 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
272 
273 	/* actually send the sleep ack packet */
274 	hci_uart_tx_wakeup(hu);
275 }
276 
277 /*
278  * Called upon wake-up-acknowledgement from the device
279  */
280 static void ll_device_woke_up(struct hci_uart *hu)
281 {
282 	unsigned long flags;
283 	struct ll_struct *ll = hu->priv;
284 
285 	BT_DBG("hu %p", hu);
286 
287 	/* lock hcill state */
288 	spin_lock_irqsave(&ll->hcill_lock, flags);
289 
290 	/* sanity check */
291 	if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
292 		BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
293 
294 	/* send pending packets and change state to HCILL_AWAKE */
295 	__ll_do_awake(ll);
296 
297 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
298 
299 	/* actually send the packets */
300 	hci_uart_tx_wakeup(hu);
301 }
302 
303 /* Enqueue frame for transmittion (padding, crc, etc) */
304 /* may be called from two simultaneous tasklets */
305 static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
306 {
307 	unsigned long flags = 0;
308 	struct ll_struct *ll = hu->priv;
309 
310 	BT_DBG("hu %p skb %p", hu, skb);
311 
312 	/* Prepend skb with frame type */
313 	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
314 
315 	/* lock hcill state */
316 	spin_lock_irqsave(&ll->hcill_lock, flags);
317 
318 	/* act according to current state */
319 	switch (ll->hcill_state) {
320 	case HCILL_AWAKE:
321 		BT_DBG("device awake, sending normally");
322 		skb_queue_tail(&ll->txq, skb);
323 		break;
324 	case HCILL_ASLEEP:
325 		BT_DBG("device asleep, waking up and queueing packet");
326 		/* save packet for later */
327 		skb_queue_tail(&ll->tx_wait_q, skb);
328 		/* awake device */
329 		if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
330 			BT_ERR("cannot wake up device");
331 			break;
332 		}
333 		ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
334 		break;
335 	case HCILL_ASLEEP_TO_AWAKE:
336 		BT_DBG("device waking up, queueing packet");
337 		/* transient state; just keep packet for later */
338 		skb_queue_tail(&ll->tx_wait_q, skb);
339 		break;
340 	default:
341 		BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
342 		kfree_skb(skb);
343 		break;
344 	}
345 
346 	spin_unlock_irqrestore(&ll->hcill_lock, flags);
347 
348 	return 0;
349 }
350 
351 static int ll_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
352 {
353 	struct hci_uart *hu = hci_get_drvdata(hdev);
354 	struct ll_struct *ll = hu->priv;
355 
356 	switch (hci_skb_pkt_type(skb)) {
357 	case HCILL_GO_TO_SLEEP_IND:
358 		BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
359 		ll_device_want_to_sleep(hu);
360 		break;
361 	case HCILL_GO_TO_SLEEP_ACK:
362 		/* shouldn't happen */
363 		bt_dev_err(hdev, "received HCILL_GO_TO_SLEEP_ACK in state %ld",
364 			   ll->hcill_state);
365 		break;
366 	case HCILL_WAKE_UP_IND:
367 		BT_DBG("HCILL_WAKE_UP_IND packet");
368 		ll_device_want_to_wakeup(hu);
369 		break;
370 	case HCILL_WAKE_UP_ACK:
371 		BT_DBG("HCILL_WAKE_UP_ACK packet");
372 		ll_device_woke_up(hu);
373 		break;
374 	}
375 
376 	kfree_skb(skb);
377 	return 0;
378 }
379 
380 #define LL_RECV_SLEEP_IND \
381 	.type = HCILL_GO_TO_SLEEP_IND, \
382 	.hlen = 0, \
383 	.loff = 0, \
384 	.lsize = 0, \
385 	.maxlen = 0
386 
387 #define LL_RECV_SLEEP_ACK \
388 	.type = HCILL_GO_TO_SLEEP_ACK, \
389 	.hlen = 0, \
390 	.loff = 0, \
391 	.lsize = 0, \
392 	.maxlen = 0
393 
394 #define LL_RECV_WAKE_IND \
395 	.type = HCILL_WAKE_UP_IND, \
396 	.hlen = 0, \
397 	.loff = 0, \
398 	.lsize = 0, \
399 	.maxlen = 0
400 
401 #define LL_RECV_WAKE_ACK \
402 	.type = HCILL_WAKE_UP_ACK, \
403 	.hlen = 0, \
404 	.loff = 0, \
405 	.lsize = 0, \
406 	.maxlen = 0
407 
408 static const struct h4_recv_pkt ll_recv_pkts[] = {
409 	{ H4_RECV_ACL,       .recv = hci_recv_frame },
410 	{ H4_RECV_SCO,       .recv = hci_recv_frame },
411 	{ H4_RECV_EVENT,     .recv = hci_recv_frame },
412 	{ LL_RECV_SLEEP_IND, .recv = ll_recv_frame  },
413 	{ LL_RECV_SLEEP_ACK, .recv = ll_recv_frame  },
414 	{ LL_RECV_WAKE_IND,  .recv = ll_recv_frame  },
415 	{ LL_RECV_WAKE_ACK,  .recv = ll_recv_frame  },
416 };
417 
418 /* Recv data */
419 static int ll_recv(struct hci_uart *hu, const void *data, int count)
420 {
421 	struct ll_struct *ll = hu->priv;
422 
423 	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
424 		return -EUNATCH;
425 
426 	ll->rx_skb = h4_recv_buf(hu->hdev, ll->rx_skb, data, count,
427 				 ll_recv_pkts, ARRAY_SIZE(ll_recv_pkts));
428 	if (IS_ERR(ll->rx_skb)) {
429 		int err = PTR_ERR(ll->rx_skb);
430 		bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
431 		ll->rx_skb = NULL;
432 		return err;
433 	}
434 
435 	return count;
436 }
437 
438 static struct sk_buff *ll_dequeue(struct hci_uart *hu)
439 {
440 	struct ll_struct *ll = hu->priv;
441 	return skb_dequeue(&ll->txq);
442 }
443 
444 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
445 static int read_local_version(struct hci_dev *hdev)
446 {
447 	int err = 0;
448 	unsigned short version = 0;
449 	struct sk_buff *skb;
450 	struct hci_rp_read_local_version *ver;
451 
452 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL, HCI_INIT_TIMEOUT);
453 	if (IS_ERR(skb)) {
454 		bt_dev_err(hdev, "Reading TI version information failed (%ld)",
455 			   PTR_ERR(skb));
456 		return PTR_ERR(skb);
457 	}
458 	if (skb->len != sizeof(*ver)) {
459 		err = -EILSEQ;
460 		goto out;
461 	}
462 
463 	ver = (struct hci_rp_read_local_version *)skb->data;
464 	if (le16_to_cpu(ver->manufacturer) != 13) {
465 		err = -ENODEV;
466 		goto out;
467 	}
468 
469 	version = le16_to_cpu(ver->lmp_subver);
470 
471 out:
472 	if (err) bt_dev_err(hdev, "Failed to read TI version info: %d", err);
473 	kfree_skb(skb);
474 	return err ? err : version;
475 }
476 
477 /**
478  * download_firmware -
479  *	internal function which parses through the .bts firmware
480  *	script file intreprets SEND, DELAY actions only as of now
481  */
482 static int download_firmware(struct ll_device *lldev)
483 {
484 	unsigned short chip, min_ver, maj_ver;
485 	int version, err, len;
486 	unsigned char *ptr, *action_ptr;
487 	unsigned char bts_scr_name[40];	/* 40 char long bts scr name? */
488 	const struct firmware *fw;
489 	struct sk_buff *skb;
490 	struct hci_command *cmd;
491 
492 	version = read_local_version(lldev->hu.hdev);
493 	if (version < 0)
494 		return version;
495 
496 	chip = (version & 0x7C00) >> 10;
497 	min_ver = (version & 0x007F);
498 	maj_ver = (version & 0x0380) >> 7;
499 	if (version & 0x8000)
500 		maj_ver |= 0x0008;
501 
502 	snprintf(bts_scr_name, sizeof(bts_scr_name),
503 		 "ti-connectivity/TIInit_%d.%d.%d.bts",
504 		 chip, maj_ver, min_ver);
505 
506 	err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
507 	if (err || !fw->data || !fw->size) {
508 		bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
509 			   err, bts_scr_name);
510 		return -EINVAL;
511 	}
512 	ptr = (void *)fw->data;
513 	len = fw->size;
514 	/* bts_header to remove out magic number and
515 	 * version
516 	 */
517 	ptr += sizeof(struct bts_header);
518 	len -= sizeof(struct bts_header);
519 
520 	while (len > 0 && ptr) {
521 		bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
522 			   ((struct bts_action *)ptr)->size,
523 			   ((struct bts_action *)ptr)->type);
524 
525 		action_ptr = &(((struct bts_action *)ptr)->data[0]);
526 
527 		switch (((struct bts_action *)ptr)->type) {
528 		case ACTION_SEND_COMMAND:	/* action send */
529 			bt_dev_dbg(lldev->hu.hdev, "S");
530 			cmd = (struct hci_command *)action_ptr;
531 			if (cmd->opcode == HCI_VS_UPDATE_UART_HCI_BAUDRATE) {
532 				/* ignore remote change
533 				 * baud rate HCI VS command
534 				 */
535 				bt_dev_warn(lldev->hu.hdev, "change remote baud rate command in firmware");
536 				break;
537 			}
538 			if (cmd->prefix != 1)
539 				bt_dev_dbg(lldev->hu.hdev, "command type %d", cmd->prefix);
540 
541 			skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen, &cmd->speed, HCI_INIT_TIMEOUT);
542 			if (IS_ERR(skb)) {
543 				bt_dev_err(lldev->hu.hdev, "send command failed");
544 				err = PTR_ERR(skb);
545 				goto out_rel_fw;
546 			}
547 			kfree_skb(skb);
548 			break;
549 		case ACTION_WAIT_EVENT:  /* wait */
550 			/* no need to wait as command was synchronous */
551 			bt_dev_dbg(lldev->hu.hdev, "W");
552 			break;
553 		case ACTION_DELAY:	/* sleep */
554 			bt_dev_info(lldev->hu.hdev, "sleep command in scr");
555 			msleep(((struct bts_action_delay *)action_ptr)->msec);
556 			break;
557 		}
558 		len -= (sizeof(struct bts_action) +
559 			((struct bts_action *)ptr)->size);
560 		ptr += sizeof(struct bts_action) +
561 			((struct bts_action *)ptr)->size;
562 	}
563 
564 out_rel_fw:
565 	/* fw download complete */
566 	release_firmware(fw);
567 	return err;
568 }
569 
570 static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
571 {
572 	bdaddr_t bdaddr_swapped;
573 	struct sk_buff *skb;
574 
575 	/* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
576 	 * address to be MSB first, but bdaddr_t has the convention of being
577 	 * LSB first.
578 	 */
579 	baswap(&bdaddr_swapped, bdaddr);
580 	skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
581 			     &bdaddr_swapped, HCI_INIT_TIMEOUT);
582 	if (!IS_ERR(skb))
583 		kfree_skb(skb);
584 
585 	return PTR_ERR_OR_ZERO(skb);
586 }
587 
588 static int ll_setup(struct hci_uart *hu)
589 {
590 	int err, retry = 3;
591 	struct ll_device *lldev;
592 	struct serdev_device *serdev = hu->serdev;
593 	u32 speed;
594 
595 	if (!serdev)
596 		return 0;
597 
598 	lldev = serdev_device_get_drvdata(serdev);
599 
600 	hu->hdev->set_bdaddr = ll_set_bdaddr;
601 
602 	serdev_device_set_flow_control(serdev, true);
603 
604 	do {
605 		/* Reset the Bluetooth device */
606 		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
607 		msleep(5);
608 		gpiod_set_value_cansleep(lldev->enable_gpio, 1);
609 		err = serdev_device_wait_for_cts(serdev, true, 200);
610 		if (err) {
611 			bt_dev_err(hu->hdev, "Failed to get CTS");
612 			return err;
613 		}
614 
615 		err = download_firmware(lldev);
616 		if (!err)
617 			break;
618 
619 		/* Toggle BT_EN and retry */
620 		bt_dev_err(hu->hdev, "download firmware failed, retrying...");
621 	} while (retry--);
622 
623 	if (err)
624 		return err;
625 
626 	/* Set BD address if one was specified at probe */
627 	if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
628 		/* This means that there was an error getting the BD address
629 		 * during probe, so mark the device as having a bad address.
630 		 */
631 		set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
632 	} else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
633 		err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
634 		if (err)
635 			set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
636 	}
637 
638 	/* Operational speed if any */
639 	if (hu->oper_speed)
640 		speed = hu->oper_speed;
641 	else if (hu->proto->oper_speed)
642 		speed = hu->proto->oper_speed;
643 	else
644 		speed = 0;
645 
646 	if (speed) {
647 		__le32 speed_le = cpu_to_le32(speed);
648 		struct sk_buff *skb;
649 
650 		skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
651 				     sizeof(speed_le), &speed_le,
652 				     HCI_INIT_TIMEOUT);
653 		if (!IS_ERR(skb)) {
654 			kfree_skb(skb);
655 			serdev_device_set_baudrate(serdev, speed);
656 		}
657 	}
658 
659 	return 0;
660 }
661 
662 static const struct hci_uart_proto llp;
663 
664 static int hci_ti_probe(struct serdev_device *serdev)
665 {
666 	struct hci_uart *hu;
667 	struct ll_device *lldev;
668 	struct nvmem_cell *bdaddr_cell;
669 	u32 max_speed = 3000000;
670 
671 	lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
672 	if (!lldev)
673 		return -ENOMEM;
674 	hu = &lldev->hu;
675 
676 	serdev_device_set_drvdata(serdev, lldev);
677 	lldev->serdev = hu->serdev = serdev;
678 
679 	lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev, "enable", GPIOD_OUT_LOW);
680 	if (IS_ERR(lldev->enable_gpio))
681 		return PTR_ERR(lldev->enable_gpio);
682 
683 	lldev->ext_clk = devm_clk_get(&serdev->dev, "ext_clock");
684 	if (IS_ERR(lldev->ext_clk) && PTR_ERR(lldev->ext_clk) != -ENOENT)
685 		return PTR_ERR(lldev->ext_clk);
686 
687 	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
688 	hci_uart_set_speeds(hu, 115200, max_speed);
689 
690 	/* optional BD address from nvram */
691 	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
692 	if (IS_ERR(bdaddr_cell)) {
693 		int err = PTR_ERR(bdaddr_cell);
694 
695 		if (err == -EPROBE_DEFER)
696 			return err;
697 
698 		/* ENOENT means there is no matching nvmem cell and ENOSYS
699 		 * means that nvmem is not enabled in the kernel configuration.
700 		 */
701 		if (err != -ENOENT && err != -ENOSYS) {
702 			/* If there was some other error, give userspace a
703 			 * chance to fix the problem instead of failing to load
704 			 * the driver. Using BDADDR_NONE as a flag that is
705 			 * tested later in the setup function.
706 			 */
707 			dev_warn(&serdev->dev,
708 				 "Failed to get \"bd-address\" nvmem cell (%d)\n",
709 				 err);
710 			bacpy(&lldev->bdaddr, BDADDR_NONE);
711 		}
712 	} else {
713 		bdaddr_t *bdaddr;
714 		size_t len;
715 
716 		bdaddr = nvmem_cell_read(bdaddr_cell, &len);
717 		nvmem_cell_put(bdaddr_cell);
718 		if (IS_ERR(bdaddr)) {
719 			dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
720 			return PTR_ERR(bdaddr);
721 		}
722 		if (len != sizeof(bdaddr_t)) {
723 			dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
724 			kfree(bdaddr);
725 			return -EINVAL;
726 		}
727 
728 		/* As per the device tree bindings, the value from nvmem is
729 		 * expected to be MSB first, but in the kernel it is expected
730 		 * that bdaddr_t is LSB first.
731 		 */
732 		baswap(&lldev->bdaddr, bdaddr);
733 		kfree(bdaddr);
734 	}
735 
736 	return hci_uart_register_device(hu, &llp);
737 }
738 
739 static void hci_ti_remove(struct serdev_device *serdev)
740 {
741 	struct ll_device *lldev = serdev_device_get_drvdata(serdev);
742 
743 	hci_uart_unregister_device(&lldev->hu);
744 }
745 
746 static const struct of_device_id hci_ti_of_match[] = {
747 	{ .compatible = "ti,cc2560" },
748 	{ .compatible = "ti,wl1271-st" },
749 	{ .compatible = "ti,wl1273-st" },
750 	{ .compatible = "ti,wl1281-st" },
751 	{ .compatible = "ti,wl1283-st" },
752 	{ .compatible = "ti,wl1285-st" },
753 	{ .compatible = "ti,wl1801-st" },
754 	{ .compatible = "ti,wl1805-st" },
755 	{ .compatible = "ti,wl1807-st" },
756 	{ .compatible = "ti,wl1831-st" },
757 	{ .compatible = "ti,wl1835-st" },
758 	{ .compatible = "ti,wl1837-st" },
759 	{},
760 };
761 MODULE_DEVICE_TABLE(of, hci_ti_of_match);
762 
763 static struct serdev_device_driver hci_ti_drv = {
764 	.driver		= {
765 		.name	= "hci-ti",
766 		.of_match_table = of_match_ptr(hci_ti_of_match),
767 	},
768 	.probe	= hci_ti_probe,
769 	.remove	= hci_ti_remove,
770 };
771 #else
772 #define ll_setup NULL
773 #endif
774 
775 static const struct hci_uart_proto llp = {
776 	.id		= HCI_UART_LL,
777 	.name		= "LL",
778 	.setup		= ll_setup,
779 	.open		= ll_open,
780 	.close		= ll_close,
781 	.recv		= ll_recv,
782 	.enqueue	= ll_enqueue,
783 	.dequeue	= ll_dequeue,
784 	.flush		= ll_flush,
785 };
786 
787 int __init ll_init(void)
788 {
789 	serdev_device_driver_register(&hci_ti_drv);
790 
791 	return hci_uart_register_proto(&llp);
792 }
793 
794 int __exit ll_deinit(void)
795 {
796 	serdev_device_driver_unregister(&hci_ti_drv);
797 
798 	return hci_uart_unregister_proto(&llp);
799 }
800