summaryrefslogtreecommitdiffstats
path: root/drivers/bluetooth/hci_nokia.c
blob: 6463350b79779b7df309f1a535a7f03489ef268e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Bluetooth HCI UART H4 driver with Nokia Extensions AKA Nokia H4+
 *
 *  Copyright (C) 2015 Marcel Holtmann <marcel@holtmann.org>
 *  Copyright (C) 2015-2017 Sebastian Reichel <sre@kernel.org>
 */

#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/firmware.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_runtime.h>
#include <linux/serdev.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/unaligned.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#include "hci_uart.h"
#include "btbcm.h"

#define VERSION "0.1"

#define NOKIA_ID_BCM2048	0x04
#define NOKIA_ID_TI1271		0x31

#define FIRMWARE_BCM2048	"nokia/bcmfw.bin"
#define FIRMWARE_TI1271		"nokia/ti1273.bin"

#define HCI_NOKIA_NEG_PKT	0x06
#define HCI_NOKIA_ALIVE_PKT	0x07
#define HCI_NOKIA_RADIO_PKT	0x08

#define HCI_NOKIA_NEG_HDR_SIZE		1
#define HCI_NOKIA_MAX_NEG_SIZE		255
#define HCI_NOKIA_ALIVE_HDR_SIZE	1
#define HCI_NOKIA_MAX_ALIVE_SIZE	255
#define HCI_NOKIA_RADIO_HDR_SIZE	2
#define HCI_NOKIA_MAX_RADIO_SIZE	255

#define NOKIA_PROTO_PKT		0x44
#define NOKIA_PROTO_BYTE	0x4c

#define NOKIA_NEG_REQ		0x00
#define NOKIA_NEG_ACK		0x20
#define NOKIA_NEG_NAK		0x40

#define H4_TYPE_SIZE		1

#define NOKIA_RECV_ALIVE \
	.type = HCI_NOKIA_ALIVE_PKT, \
	.hlen = HCI_NOKIA_ALIVE_HDR_SIZE, \
	.loff = 0, \
	.lsize = 1, \
	.maxlen = HCI_NOKIA_MAX_ALIVE_SIZE \

#define NOKIA_RECV_NEG \
	.type = HCI_NOKIA_NEG_PKT, \
	.hlen = HCI_NOKIA_NEG_HDR_SIZE, \
	.loff = 0, \
	.lsize = 1, \
	.maxlen = HCI_NOKIA_MAX_NEG_SIZE \

#define NOKIA_RECV_RADIO \
	.type = HCI_NOKIA_RADIO_PKT, \
	.hlen = HCI_NOKIA_RADIO_HDR_SIZE, \
	.loff = 1, \
	.lsize = 1, \
	.maxlen = HCI_NOKIA_MAX_RADIO_SIZE \

struct hci_nokia_neg_hdr {
	u8	dlen;
} __packed;

struct hci_nokia_neg_cmd {
	u8	ack;
	u16	baud;
	u16	unused1;
	u8	proto;
	u16	sys_clk;
	u16	unused2;
} __packed;

#define NOKIA_ALIVE_REQ   0x55
#define NOKIA_ALIVE_RESP  0xcc

struct hci_nokia_alive_hdr {
	u8	dlen;
} __packed;

struct hci_nokia_alive_pkt {
	u8	mid;
	u8	unused;
} __packed;

struct hci_nokia_neg_evt {
	u8	ack;
	u16	baud;
	u16	unused1;
	u8	proto;
	u16	sys_clk;
	u16	unused2;
	u8	man_id;
	u8	ver_id;
} __packed;

#define MAX_BAUD_RATE		3692300
#define SETUP_BAUD_RATE		921600
#define INIT_BAUD_RATE		120000

struct hci_nokia_radio_hdr {
	u8	evt;
	u8	dlen;
} __packed;

struct nokia_bt_dev {
	struct hci_uart hu;
	struct serdev_device *serdev;

	struct gpio_desc *reset;
	struct gpio_desc *wakeup_host;
	struct gpio_desc *wakeup_bt;
	unsigned long sysclk_speed;

	int wake_irq;
	struct sk_buff *rx_skb;
	struct sk_buff_head txq;
	bdaddr_t bdaddr;

	int init_error;
	struct completion init_completion;

	u8 man_id;
	u8 ver_id;

	bool initialized;
	bool tx_enabled;
	bool rx_enabled;
};

static int nokia_enqueue(struct hci_uart *hu, struct sk_buff *skb);

static void nokia_flow_control(struct serdev_device *serdev, bool enable)
{
	if (enable) {
		serdev_device_set_rts(serdev, true);
		serdev_device_set_flow_control(serdev, true);
	} else {
		serdev_device_set_flow_control(serdev, false);
		serdev_device_set_rts(serdev, false);
	}
}

static irqreturn_t wakeup_handler(int irq, void *data)
{
	struct nokia_bt_dev *btdev = data;
	struct device *dev = &btdev->serdev->dev;
	int wake_state = gpiod_get_value(btdev->wakeup_host);

	if (btdev->rx_enabled == wake_state)
		return IRQ_HANDLED;

	if (wake_state)
		pm_runtime_get(dev);
	else
		pm_runtime_put(dev);

	btdev->rx_enabled = wake_state;

	return IRQ_HANDLED;
}

static int nokia_reset(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	int err;

	/* reset routine */
	gpiod_set_value_cansleep(btdev->reset, 1);
	gpiod_set_value_cansleep(btdev->wakeup_bt, 1);

	msleep(100);

	/* safety check */
	err = gpiod_get_value_cansleep(btdev->wakeup_host);
	if (err == 1) {
		dev_err(dev, "reset: host wakeup not low!");
		return -EPROTO;
	}

	/* flush queue */
	serdev_device_write_flush(btdev->serdev);

	/* init uart */
	nokia_flow_control(btdev->serdev, false);
	serdev_device_set_baudrate(btdev->serdev, INIT_BAUD_RATE);

	gpiod_set_value_cansleep(btdev->reset, 0);

	/* wait for cts */
	err = serdev_device_wait_for_cts(btdev->serdev, true, 200);
	if (err < 0) {
		dev_err(dev, "CTS not received: %d", err);
		return err;
	}

	nokia_flow_control(btdev->serdev, true);

	return 0;
}

static int nokia_send_alive_packet(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	struct hci_nokia_alive_hdr *hdr;
	struct hci_nokia_alive_pkt *pkt;
	struct sk_buff *skb;
	int len;

	init_completion(&btdev->init_completion);

	len = H4_TYPE_SIZE + sizeof(*hdr) + sizeof(*pkt);
	skb = bt_skb_alloc(len, GFP_KERNEL);
	if (!skb)
		return -ENOMEM;

	hci_skb_pkt_type(skb) = HCI_NOKIA_ALIVE_PKT;
	memset(skb->data, 0x00, len);

	hdr = skb_put(skb, sizeof(*hdr));
	hdr->dlen = sizeof(*pkt);
	pkt = skb_put(skb, sizeof(*pkt));
	pkt->mid = NOKIA_ALIVE_REQ;

	nokia_enqueue(hu, skb);
	hci_uart_tx_wakeup(hu);

	dev_dbg(dev, "Alive sent");

	if (!wait_for_completion_interruptible_timeout(&btdev->init_completion,
		msecs_to_jiffies(1000))) {
		return -ETIMEDOUT;
	}

	if (btdev->init_error < 0)
		return btdev->init_error;

	return 0;
}

static int nokia_send_negotiation(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	struct hci_nokia_neg_cmd *neg_cmd;
	struct hci_nokia_neg_hdr *neg_hdr;
	struct sk_buff *skb;
	int len, err;
	u16 baud = DIV_ROUND_CLOSEST(btdev->sysclk_speed * 10, SETUP_BAUD_RATE);
	int sysclk = btdev->sysclk_speed / 1000;

	len = H4_TYPE_SIZE + sizeof(*neg_hdr) + sizeof(*neg_cmd);
	skb = bt_skb_alloc(len, GFP_KERNEL);
	if (!skb)
		return -ENOMEM;

	hci_skb_pkt_type(skb) = HCI_NOKIA_NEG_PKT;

	neg_hdr = skb_put(skb, sizeof(*neg_hdr));
	neg_hdr->dlen = sizeof(*neg_cmd);

	neg_cmd = skb_put(skb, sizeof(*neg_cmd));
	neg_cmd->ack = NOKIA_NEG_REQ;
	neg_cmd->baud = cpu_to_le16(baud);
	neg_cmd->unused1 = 0x0000;
	neg_cmd->proto = NOKIA_PROTO_BYTE;
	neg_cmd->sys_clk = cpu_to_le16(sysclk);
	neg_cmd->unused2 = 0x0000;

	btdev->init_error = 0;
	init_completion(&btdev->init_completion);

	nokia_enqueue(hu, skb);
	hci_uart_tx_wakeup(hu);

	dev_dbg(dev, "Negotiation sent");

	if (!wait_for_completion_interruptible_timeout(&btdev->init_completion,
		msecs_to_jiffies(10000))) {
		return -ETIMEDOUT;
	}

	if (btdev->init_error < 0)
		return btdev->init_error;

	/* Change to previously negotiated speed. Flow Control
	 * is disabled until bluetooth adapter is ready to avoid
	 * broken bytes being received.
	 */
	nokia_flow_control(btdev->serdev, false);
	serdev_device_set_baudrate(btdev->serdev, SETUP_BAUD_RATE);
	err = serdev_device_wait_for_cts(btdev->serdev, true, 200);
	if (err < 0) {
		dev_err(dev, "CTS not received: %d", err);
		return err;
	}
	nokia_flow_control(btdev->serdev, true);

	dev_dbg(dev, "Negotiation successful");

	return 0;
}

static int nokia_setup_fw(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	const char *fwname;
	const struct firmware *fw;
	const u8 *fw_ptr;
	size_t fw_size;
	int err;

	dev_dbg(dev, "setup firmware");

	if (btdev->man_id == NOKIA_ID_BCM2048) {
		fwname = FIRMWARE_BCM2048;
	} else if (btdev->man_id == NOKIA_ID_TI1271) {
		fwname = FIRMWARE_TI1271;
	} else {
		dev_err(dev, "Unsupported bluetooth device!");
		return -ENODEV;
	}

	err = request_firmware(&fw, fwname, dev);
	if (err < 0) {
		dev_err(dev, "%s: Failed to load Nokia firmware file (%d)",
			hu->hdev->name, err);
		return err;
	}

	fw_ptr = fw->data;
	fw_size = fw->size;

	while (fw_size >= 4) {
		u16 pkt_size = get_unaligned_le16(fw_ptr);
		u8 pkt_type = fw_ptr[2];
		const struct hci_command_hdr *cmd;
		u16 opcode;
		struct sk_buff *skb;

		switch (pkt_type) {
		case HCI_COMMAND_PKT:
			cmd = (struct hci_command_hdr *)(fw_ptr + 3);
			opcode = le16_to_cpu(cmd->opcode);

			skb = __hci_cmd_sync(hu->hdev, opcode, cmd->plen,
					     fw_ptr + 3 + HCI_COMMAND_HDR_SIZE,
					     HCI_INIT_TIMEOUT);
			if (IS_ERR(skb)) {
				err = PTR_ERR(skb);
				dev_err(dev, "%s: FW command %04x failed (%d)",
				       hu->hdev->name, opcode, err);
				goto done;
			}
			kfree_skb(skb);
			break;
		case HCI_NOKIA_RADIO_PKT:
		case HCI_NOKIA_NEG_PKT:
		case HCI_NOKIA_ALIVE_PKT:
			break;
		}

		fw_ptr += pkt_size + 2;
		fw_size -= pkt_size + 2;
	}

done:
	release_firmware(fw);
	return err;
}

static int nokia_setup(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	int err;

	btdev->initialized = false;

	nokia_flow_control(btdev->serdev, false);

	pm_runtime_get_sync(dev);

	if (btdev->tx_enabled) {
		gpiod_set_value_cansleep(btdev->wakeup_bt, 0);
		pm_runtime_put(&btdev->serdev->dev);
		btdev->tx_enabled = false;
	}

	dev_dbg(dev, "protocol setup");

	/* 0. reset connection */
	err = nokia_reset(hu);
	if (err < 0) {
		dev_err(dev, "Reset failed: %d", err);
		goto out;
	}

	/* 1. negotiate speed etc */
	err = nokia_send_negotiation(hu);
	if (err < 0) {
		dev_err(dev, "Negotiation failed: %d", err);
		goto out;
	}

	/* 2. verify correct setup using alive packet */
	err = nokia_send_alive_packet(hu);
	if (err < 0) {
		dev_err(dev, "Alive check failed: %d", err);
		goto out;
	}

	/* 3. send firmware */
	err = nokia_setup_fw(hu);
	if (err < 0) {
		dev_err(dev, "Could not setup FW: %d", err);
		goto out;
	}

	nokia_flow_control(btdev->serdev, false);
	serdev_device_set_baudrate(btdev->serdev, MAX_BAUD_RATE);
	nokia_flow_control(btdev->serdev, true);

	if (btdev->man_id == NOKIA_ID_BCM2048) {
		hu->hdev->set_bdaddr = btbcm_set_bdaddr;
		set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
		dev_dbg(dev, "bcm2048 has invalid bluetooth address!");
	}

	dev_dbg(dev, "protocol setup done!");

	gpiod_set_value_cansleep(btdev->wakeup_bt, 0);
	pm_runtime_put(dev);
	btdev->tx_enabled = false;
	btdev->initialized = true;

	return 0;
out:
	pm_runtime_put(dev);

	return err;
}

static int nokia_open(struct hci_uart *hu)
{
	struct device *dev = &hu->serdev->dev;

	dev_dbg(dev, "protocol open");

	pm_runtime_enable(dev);

	return 0;
}

static int nokia_flush(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;

	dev_dbg(&btdev->serdev->dev, "flush device");

	skb_queue_purge(&btdev->txq);

	return 0;
}

static int nokia_close(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;

	dev_dbg(dev, "close device");

	btdev->initialized = false;

	skb_queue_purge(&btdev->txq);

	kfree_skb(btdev->rx_skb);

	/* disable module */
	gpiod_set_value(btdev->reset, 1);
	gpiod_set_value(btdev->wakeup_bt, 0);

	pm_runtime_disable(&btdev->serdev->dev);

	return 0;
}

/* Enqueue frame for transmittion (padding, crc, etc) */
static int nokia_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
	struct nokia_bt_dev *btdev = hu->priv;
	int err;

	/* Prepend skb with frame type */
	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);

	/* Packets must be word aligned */
	if (skb->len % 2) {
		err = skb_pad(skb, 1);
		if (err)
			return err;
		skb_put_u8(skb, 0x00);
	}

	skb_queue_tail(&btdev->txq, skb);

	return 0;
}

static int nokia_recv_negotiation_packet(struct hci_dev *hdev,
					 struct sk_buff *skb)
{
	struct hci_uart *hu = hci_get_drvdata(hdev);
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	struct hci_nokia_neg_hdr *hdr;
	struct hci_nokia_neg_evt *evt;
	int ret = 0;

	hdr = (struct hci_nokia_neg_hdr *)skb->data;
	if (hdr->dlen != sizeof(*evt)) {
		btdev->init_error = -EIO;
		ret = -EIO;
		goto finish_neg;
	}

	evt = skb_pull(skb, sizeof(*hdr));

	if (evt->ack != NOKIA_NEG_ACK) {
		dev_err(dev, "Negotiation received: wrong reply");
		btdev->init_error = -EINVAL;
		ret = -EINVAL;
		goto finish_neg;
	}

	btdev->man_id = evt->man_id;
	btdev->ver_id = evt->ver_id;

	dev_dbg(dev, "Negotiation received: baud=%u:clk=%u:manu=%u:vers=%u",
		evt->baud, evt->sys_clk, evt->man_id, evt->ver_id);

finish_neg:
	complete(&btdev->init_completion);
	kfree_skb(skb);
	return ret;
}

static int nokia_recv_alive_packet(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct hci_uart *hu = hci_get_drvdata(hdev);
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	struct hci_nokia_alive_hdr *hdr;
	struct hci_nokia_alive_pkt *pkt;
	int ret = 0;

	hdr = (struct hci_nokia_alive_hdr *)skb->data;
	if (hdr->dlen != sizeof(*pkt)) {
		dev_err(dev, "Corrupted alive message");
		btdev->init_error = -EIO;
		ret = -EIO;
		goto finish_alive;
	}

	pkt = skb_pull(skb, sizeof(*hdr));

	if (pkt->mid != NOKIA_ALIVE_RESP) {
		dev_err(dev, "Alive received: invalid response: 0x%02x!",
			pkt->mid);
		btdev->init_error = -EINVAL;
		ret = -EINVAL;
		goto finish_alive;
	}

	dev_dbg(dev, "Alive received");

finish_alive:
	complete(&btdev->init_completion);
	kfree_skb(skb);
	return ret;
}

static int nokia_recv_radio(struct hci_dev *hdev, struct sk_buff *skb)
{
	/* Packets received on the dedicated radio channel are
	 * HCI events and so feed them back into the core.
	 */
	hci_skb_pkt_type(skb) = HCI_EVENT_PKT;
	return hci_recv_frame(hdev, skb);
}

/* Recv data */
static const struct h4_recv_pkt nokia_recv_pkts[] = {
	{ H4_RECV_ACL,		.recv = hci_recv_frame },
	{ H4_RECV_SCO,		.recv = hci_recv_frame },
	{ H4_RECV_EVENT,	.recv = hci_recv_frame },
	{ NOKIA_RECV_ALIVE,	.recv = nokia_recv_alive_packet },
	{ NOKIA_RECV_NEG,	.recv = nokia_recv_negotiation_packet },
	{ NOKIA_RECV_RADIO,	.recv = nokia_recv_radio },
};

static int nokia_recv(struct hci_uart *hu, const void *data, int count)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	int err;

	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
		return -EUNATCH;

	btdev->rx_skb = h4_recv_buf(hu->hdev, btdev->rx_skb, data, count,
				  nokia_recv_pkts, ARRAY_SIZE(nokia_recv_pkts));
	if (IS_ERR(btdev->rx_skb)) {
		err = PTR_ERR(btdev->rx_skb);
		dev_err(dev, "Frame reassembly failed (%d)", err);
		btdev->rx_skb = NULL;
		return err;
	}

	return count;
}

static struct sk_buff *nokia_dequeue(struct hci_uart *hu)
{
	struct nokia_bt_dev *btdev = hu->priv;
	struct device *dev = &btdev->serdev->dev;
	struct sk_buff *result = skb_dequeue(&btdev->txq);

	if (!btdev->initialized)
		return result;

	if (btdev->tx_enabled == !!result)
		return result;

	if (result) {
		pm_runtime_get_sync(dev);
		gpiod_set_value_cansleep(btdev->wakeup_bt, 1);
	} else {
		serdev_device_wait_until_sent(btdev->serdev, 0);
		gpiod_set_value_cansleep(btdev->wakeup_bt, 0);
		pm_runtime_put(dev);
	}

	btdev->tx_enabled = !!result;

	return result;
}

static const struct hci_uart_proto nokia_proto = {
	.id		= HCI_UART_NOKIA,
	.name		= "Nokia",
	.open		= nokia_open,
	.close		= nokia_close,
	.recv		= nokia_recv,
	.enqueue	= nokia_enqueue,
	.dequeue	= nokia_dequeue,
	.flush		= nokia_flush,
	.setup		= nokia_setup,
	.manufacturer	= 1,
};

static int nokia_bluetooth_serdev_probe(struct serdev_device *serdev)
{
	struct device *dev = &serdev->dev;
	struct nokia_bt_dev *btdev;
	struct clk *sysclk;
	int err = 0;

	btdev = devm_kzalloc(dev, sizeof(*btdev), GFP_KERNEL);
	if (!btdev)
		return -ENOMEM;

	btdev->hu.serdev = btdev->serdev = serdev;
	serdev_device_set_drvdata(serdev, btdev);

	btdev->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(btdev->reset)) {
		err = PTR_ERR(btdev->reset);
		dev_err(dev, "could not get reset gpio: %d", err);
		return err;
	}

	btdev->wakeup_host = devm_gpiod_get(dev, "host-wakeup", GPIOD_IN);
	if (IS_ERR(btdev->wakeup_host)) {
		err = PTR_ERR(btdev->wakeup_host);
		dev_err(dev, "could not get host wakeup gpio: %d", err);
		return err;
	}

	btdev->wake_irq = gpiod_to_irq(btdev->wakeup_host);

	err = devm_request_threaded_irq(dev, btdev->wake_irq, NULL,
		wakeup_handler,
		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
		"wakeup", btdev);
	if (err) {
		dev_err(dev, "could request wakeup irq: %d", err);
		return err;
	}

	btdev->wakeup_bt = devm_gpiod_get(dev, "bluetooth-wakeup",
					   GPIOD_OUT_LOW);
	if (IS_ERR(btdev->wakeup_bt)) {
		err = PTR_ERR(btdev->wakeup_bt);
		dev_err(dev, "could not get BT wakeup gpio: %d", err);
		return err;
	}

	sysclk = devm_clk_get(dev, "sysclk");
	if (IS_ERR(sysclk)) {
		err = PTR_ERR(sysclk);
		dev_err(dev, "could not get sysclk: %d", err);
		return err;
	}

	clk_prepare_enable(sysclk);
	btdev->sysclk_speed = clk_get_rate(sysclk);
	clk_disable_unprepare(sysclk);

	skb_queue_head_init(&btdev->txq);

	btdev->hu.priv = btdev;
	btdev->hu.alignment = 2; /* Nokia H4+ is word aligned */

	err = hci_uart_register_device(&btdev->hu, &nokia_proto);
	if (err) {
		dev_err(dev, "could not register bluetooth uart: %d", err);
		return err;
	}

	return 0;
}

static void nokia_bluetooth_serdev_remove(struct serdev_device *serdev)
{
	struct nokia_bt_dev *btdev = serdev_device_get_drvdata(serdev);

	hci_uart_unregister_device(&btdev->hu);
}

static int nokia_bluetooth_runtime_suspend(struct device *dev)
{
	struct serdev_device *serdev = to_serdev_device(dev);

	nokia_flow_control(serdev, false);
	return 0;
}

static int nokia_bluetooth_runtime_resume(struct device *dev)
{
	struct serdev_device *serdev = to_serdev_device(dev);

	nokia_flow_control(serdev, true);
	return 0;
}

static const struct dev_pm_ops nokia_bluetooth_pm_ops = {
	SET_RUNTIME_PM_OPS(nokia_bluetooth_runtime_suspend,
			   nokia_bluetooth_runtime_resume,
			   NULL)
};

#ifdef CONFIG_OF
static const struct of_device_id nokia_bluetooth_of_match[] = {
	{ .compatible = "nokia,h4p-bluetooth", },
	{},
};
MODULE_DEVICE_TABLE(of, nokia_bluetooth_of_match);
#endif

static struct serdev_device_driver nokia_bluetooth_serdev_driver = {
	.probe = nokia_bluetooth_serdev_probe,
	.remove = nokia_bluetooth_serdev_remove,
	.driver = {
		.name = "nokia-bluetooth",
		.pm = &nokia_bluetooth_pm_ops,
		.of_match_table = of_match_ptr(nokia_bluetooth_of_match),
	},
};

module_serdev_device_driver(nokia_bluetooth_serdev_driver);

MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
MODULE_DESCRIPTION("Bluetooth HCI UART Nokia H4+ driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");