summaryrefslogtreecommitdiff
path: root/drivers/bluetooth/btmtkuart.c
blob: 4593baff2bc944f5a003bb666520062f768f52e5 (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
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 MediaTek Inc.

/*
 * Bluetooth support for MediaTek serial devices
 *
 * Author: Sean Wang <sean.wang@mediatek.com>
 *
 */

#include <asm/unaligned.h>
#include <linux/atomic.h>
#include <linux/clk.h>
#include <linux/firmware.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 <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#include "h4_recv.h"

#define VERSION "0.1"

#define FIRMWARE_MT7622		"mediatek/mt7622pr2h.bin"

#define MTK_STP_TLR_SIZE	2

#define BTMTKUART_TX_STATE_ACTIVE	1
#define BTMTKUART_TX_STATE_WAKEUP	2
#define BTMTKUART_TX_WAIT_VND_EVT	3

enum {
	MTK_WMT_PATCH_DWNLD = 0x1,
	MTK_WMT_FUNC_CTRL = 0x6,
	MTK_WMT_RST = 0x7
};

struct mtk_stp_hdr {
	u8	prefix;
	__be16	dlen;
	u8	cs;
} __packed;

struct mtk_wmt_hdr {
	u8	dir;
	u8	op;
	__le16	dlen;
	u8	flag;
} __packed;

struct mtk_hci_wmt_cmd {
	struct mtk_wmt_hdr hdr;
	u8 data[256];
} __packed;

struct btmtkuart_dev {
	struct hci_dev *hdev;
	struct serdev_device *serdev;
	struct clk *clk;

	struct work_struct tx_work;
	unsigned long tx_state;
	struct sk_buff_head txq;

	struct sk_buff *rx_skb;

	u8	stp_pad[6];
	u8	stp_cursor;
	u16	stp_dlen;
};

static int mtk_hci_wmt_sync(struct hci_dev *hdev, u8 op, u8 flag, u16 plen,
			    const void *param)
{
	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
	struct mtk_hci_wmt_cmd wc;
	struct mtk_wmt_hdr *hdr;
	u32 hlen;
	int err;

	hlen = sizeof(*hdr) + plen;
	if (hlen > 255)
		return -EINVAL;

	hdr = (struct mtk_wmt_hdr *)&wc;
	hdr->dir = 1;
	hdr->op = op;
	hdr->dlen = cpu_to_le16(plen + 1);
	hdr->flag = flag;
	memcpy(wc.data, param, plen);

	set_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);

	err = __hci_cmd_send(hdev, 0xfc6f, hlen, &wc);
	if (err < 0) {
		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
		return err;
	}

	/* The vendor specific WMT commands are all answered by a vendor
	 * specific event and will not have the Command Status or Command
	 * Complete as with usual HCI command flow control.
	 *
	 * After sending the command, wait for BTMTKUART_TX_WAIT_VND_EVT
	 * state to be cleared. The driver speicfic event receive routine
	 * will clear that state and with that indicate completion of the
	 * WMT command.
	 */
	err = wait_on_bit_timeout(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT,
				  TASK_INTERRUPTIBLE, HCI_INIT_TIMEOUT);
	if (err == -EINTR) {
		bt_dev_err(hdev, "Execution of wmt command interrupted");
		return err;
	}

	if (err) {
		bt_dev_err(hdev, "Execution of wmt command timed out");
		return -ETIMEDOUT;
	}

	return 0;
}

static int mtk_setup_fw(struct hci_dev *hdev)
{
	const struct firmware *fw;
	const u8 *fw_ptr;
	size_t fw_size;
	int err, dlen;
	u8 flag;

	err = request_firmware(&fw, FIRMWARE_MT7622, &hdev->dev);
	if (err < 0) {
		bt_dev_err(hdev, "Failed to load firmware file (%d)", err);
		return err;
	}

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

	/* The size of patch header is 30 bytes, should be skip */
	if (fw_size < 30) {
		err = -EINVAL;
		goto free_fw;
	}

	fw_size -= 30;
	fw_ptr += 30;
	flag = 1;

	while (fw_size > 0) {
		dlen = min_t(int, 250, fw_size);

		/* Tell device the position in sequence */
		if (fw_size - dlen <= 0)
			flag = 3;
		else if (fw_size < fw->size - 30)
			flag = 2;

		err = mtk_hci_wmt_sync(hdev, MTK_WMT_PATCH_DWNLD, flag, dlen,
				       fw_ptr);
		if (err < 0) {
			bt_dev_err(hdev, "Failed to send wmt patch dwnld (%d)",
				   err);
			break;
		}

		fw_size -= dlen;
		fw_ptr += dlen;
	}

free_fw:
	release_firmware(fw);
	return err;
}

static int btmtkuart_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
	struct hci_event_hdr *hdr = (void *)skb->data;
	int err;

	/* Fix up the vendor event id with 0xff for vendor specific instead
	 * of 0xe4 so that event send via monitoring socket can be parsed
	 * properly.
	 */
	if (hdr->evt == 0xe4)
		hdr->evt = HCI_EV_VENDOR;

	err = hci_recv_frame(hdev, skb);

	if (hdr->evt == HCI_EV_VENDOR) {
		if (test_and_clear_bit(BTMTKUART_TX_WAIT_VND_EVT,
				       &bdev->tx_state)) {
			/* Barrier to sync with other CPUs */
			smp_mb__after_atomic();
			wake_up_bit(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT);
		}
	}

	return err;
}

static const struct h4_recv_pkt mtk_recv_pkts[] = {
	{ H4_RECV_ACL,      .recv = hci_recv_frame },
	{ H4_RECV_SCO,      .recv = hci_recv_frame },
	{ H4_RECV_EVENT,    .recv = btmtkuart_recv_event },
};

static void btmtkuart_tx_work(struct work_struct *work)
{
	struct btmtkuart_dev *bdev = container_of(work, struct btmtkuart_dev,
						   tx_work);
	struct serdev_device *serdev = bdev->serdev;
	struct hci_dev *hdev = bdev->hdev;

	while (1) {
		clear_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);

		while (1) {
			struct sk_buff *skb = skb_dequeue(&bdev->txq);
			int len;

			if (!skb)
				break;

			len = serdev_device_write_buf(serdev, skb->data,
						      skb->len);
			hdev->stat.byte_tx += len;

			skb_pull(skb, len);
			if (skb->len > 0) {
				skb_queue_head(&bdev->txq, skb);
				break;
			}

			switch (hci_skb_pkt_type(skb)) {
			case HCI_COMMAND_PKT:
				hdev->stat.cmd_tx++;
				break;
			case HCI_ACLDATA_PKT:
				hdev->stat.acl_tx++;
				break;
			case HCI_SCODATA_PKT:
				hdev->stat.sco_tx++;
				break;
			}

			kfree_skb(skb);
		}

		if (!test_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state))
			break;
	}

	clear_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state);
}

static void btmtkuart_tx_wakeup(struct btmtkuart_dev *bdev)
{
	if (test_and_set_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state))
		set_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);

	schedule_work(&bdev->tx_work);
}

static const unsigned char *
mtk_stp_split(struct btmtkuart_dev *bdev, const unsigned char *data, int count,
	      int *sz_h4)
{
	struct mtk_stp_hdr *shdr;

	/* The cursor is reset when all the data of STP is consumed out */
	if (!bdev->stp_dlen && bdev->stp_cursor >= 6)
		bdev->stp_cursor = 0;

	/* Filling pad until all STP info is obtained */
	while (bdev->stp_cursor < 6 && count > 0) {
		bdev->stp_pad[bdev->stp_cursor] = *data;
		bdev->stp_cursor++;
		data++;
		count--;
	}

	/* Retrieve STP info and have a sanity check */
	if (!bdev->stp_dlen && bdev->stp_cursor >= 6) {
		shdr = (struct mtk_stp_hdr *)&bdev->stp_pad[2];
		bdev->stp_dlen = be16_to_cpu(shdr->dlen) & 0x0fff;

		/* Resync STP when unexpected data is being read */
		if (shdr->prefix != 0x80 || bdev->stp_dlen > 2048) {
			bt_dev_err(bdev->hdev, "stp format unexpect (%d, %d)",
				   shdr->prefix, bdev->stp_dlen);
			bdev->stp_cursor = 2;
			bdev->stp_dlen = 0;
		}
	}

	/* Directly quit when there's no data found for H4 can process */
	if (count <= 0)
		return NULL;

	/* Tranlate to how much the size of data H4 can handle so far */
	*sz_h4 = min_t(int, count, bdev->stp_dlen);

	/* Update the remaining size of STP packet */
	bdev->stp_dlen -= *sz_h4;

	/* Data points to STP payload which can be handled by H4 */
	return data;
}

static int btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
{
	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
	const unsigned char *p_left = data, *p_h4;
	int sz_left = count, sz_h4, adv;
	int err;

	while (sz_left > 0) {
		/*  The serial data received from MT7622 BT controller is
		 *  at all time padded around with the STP header and tailer.
		 *
		 *  A full STP packet is looking like
		 *   -----------------------------------
		 *  | STP header  |  H:4   | STP tailer |
		 *   -----------------------------------
		 *  but it doesn't guarantee to contain a full H:4 packet which
		 *  means that it's possible for multiple STP packets forms a
		 *  full H:4 packet that means extra STP header + length doesn't
		 *  indicate a full H:4 frame, things can fragment. Whose length
		 *  recorded in STP header just shows up the most length the
		 *  H:4 engine can handle currently.
		 */

		p_h4 = mtk_stp_split(bdev, p_left, sz_left, &sz_h4);
		if (!p_h4)
			break;

		adv = p_h4 - p_left;
		sz_left -= adv;
		p_left += adv;

		bdev->rx_skb = h4_recv_buf(bdev->hdev, bdev->rx_skb, p_h4,
					   sz_h4, mtk_recv_pkts,
					   ARRAY_SIZE(mtk_recv_pkts));
		if (IS_ERR(bdev->rx_skb)) {
			err = PTR_ERR(bdev->rx_skb);
			bt_dev_err(bdev->hdev,
				   "Frame reassembly failed (%d)", err);
			bdev->rx_skb = NULL;
			return err;
		}

		sz_left -= sz_h4;
		p_left += sz_h4;
	}

	return 0;
}

static int btmtkuart_receive_buf(struct serdev_device *serdev, const u8 *data,
				 size_t count)
{
	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
	int err;

	err = btmtkuart_recv(bdev->hdev, data, count);
	if (err < 0)
		return err;

	bdev->hdev->stat.byte_rx += count;

	return count;
}

static void btmtkuart_write_wakeup(struct serdev_device *serdev)
{
	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);

	btmtkuart_tx_wakeup(bdev);
}

static const struct serdev_device_ops btmtkuart_client_ops = {
	.receive_buf = btmtkuart_receive_buf,
	.write_wakeup = btmtkuart_write_wakeup,
};

static int btmtkuart_open(struct hci_dev *hdev)
{
	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
	struct device *dev;
	int err;

	err = serdev_device_open(bdev->serdev);
	if (err) {
		bt_dev_err(hdev, "Unable to open UART device %s",
			   dev_name(&bdev->serdev->dev));
		goto err_open;
	}

	bdev->stp_cursor = 2;
	bdev->stp_dlen = 0;

	dev = &bdev->serdev->dev;

	/* Enable the power domain and clock the device requires */
	pm_runtime_enable(dev);
	err = pm_runtime_get_sync(dev);
	if (err < 0) {
		pm_runtime_put_noidle(dev);
		goto err_disable_rpm;
	}

	err = clk_prepare_enable(bdev->clk);
	if (err < 0)
		goto err_put_rpm;

	return 0;

err_put_rpm:
	pm_runtime_put_sync(dev);
err_disable_rpm:
	pm_runtime_disable(dev);
err_open:
	return err;
}

static int btmtkuart_close(struct hci_dev *hdev)
{
	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
	struct device *dev = &bdev->serdev->dev;

	/* Shutdown the clock and power domain the device requires */
	clk_disable_unprepare(bdev->clk);
	pm_runtime_put_sync(dev);
	pm_runtime_disable(dev);

	serdev_device_close(bdev->serdev);

	return 0;
}

static int btmtkuart_flush(struct hci_dev *hdev)
{
	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);

	/* Flush any pending characters */
	serdev_device_write_flush(bdev->serdev);
	skb_queue_purge(&bdev->txq);

	cancel_work_sync(&bdev->tx_work);

	kfree_skb(bdev->rx_skb);
	bdev->rx_skb = NULL;

	bdev->stp_cursor = 2;
	bdev->stp_dlen = 0;

	return 0;
}

static int btmtkuart_setup(struct hci_dev *hdev)
{
	u8 param = 0x1;
	int err = 0;

	/* Setup a firmware which the device definitely requires */
	err = mtk_setup_fw(hdev);
	if (err < 0)
		return err;

	/* Activate function the firmware providing to */
	err = mtk_hci_wmt_sync(hdev, MTK_WMT_RST, 0x4, 0, 0);
	if (err < 0) {
		bt_dev_err(hdev, "Failed to send wmt rst (%d)", err);
		return err;
	}

	/* Enable Bluetooth protocol */
	err = mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
			       &param);
	if (err < 0) {
		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
		return err;
	}

	return 0;
}

static int btmtkuart_shutdown(struct hci_dev *hdev)
{
	u8 param = 0x0;
	int err;

	/* Disable the device */
	err = mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
			       &param);
	if (err < 0) {
		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
		return err;
	}

	return 0;
}

static int btmtkuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
	struct mtk_stp_hdr *shdr;
	int err, dlen, type = 0;

	/* Prepend skb with frame type */
	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);

	/* Make sure that there is enough rooms for STP header and trailer */
	if (unlikely(skb_headroom(skb) < sizeof(*shdr)) ||
	    (skb_tailroom(skb) < MTK_STP_TLR_SIZE)) {
		err = pskb_expand_head(skb, sizeof(*shdr), MTK_STP_TLR_SIZE,
				       GFP_ATOMIC);
		if (err < 0)
			return err;
	}

	/* Add the STP header */
	dlen = skb->len;
	shdr = skb_push(skb, sizeof(*shdr));
	shdr->prefix = 0x80;
	shdr->dlen = cpu_to_be16((dlen & 0x0fff) | (type << 12));
	shdr->cs = 0;		/* MT7622 doesn't care about checksum value */

	/* Add the STP trailer */
	skb_put_zero(skb, MTK_STP_TLR_SIZE);

	skb_queue_tail(&bdev->txq, skb);

	btmtkuart_tx_wakeup(bdev);
	return 0;
}

static int btmtkuart_probe(struct serdev_device *serdev)
{
	struct btmtkuart_dev *bdev;
	struct hci_dev *hdev;

	bdev = devm_kzalloc(&serdev->dev, sizeof(*bdev), GFP_KERNEL);
	if (!bdev)
		return -ENOMEM;

	bdev->clk = devm_clk_get(&serdev->dev, "ref");
	if (IS_ERR(bdev->clk))
		return PTR_ERR(bdev->clk);

	bdev->serdev = serdev;
	serdev_device_set_drvdata(serdev, bdev);

	serdev_device_set_client_ops(serdev, &btmtkuart_client_ops);

	INIT_WORK(&bdev->tx_work, btmtkuart_tx_work);
	skb_queue_head_init(&bdev->txq);

	/* Initialize and register HCI device */
	hdev = hci_alloc_dev();
	if (!hdev) {
		dev_err(&serdev->dev, "Can't allocate HCI device\n");
		return -ENOMEM;
	}

	bdev->hdev = hdev;

	hdev->bus = HCI_UART;
	hci_set_drvdata(hdev, bdev);

	hdev->open     = btmtkuart_open;
	hdev->close    = btmtkuart_close;
	hdev->flush    = btmtkuart_flush;
	hdev->setup    = btmtkuart_setup;
	hdev->shutdown = btmtkuart_shutdown;
	hdev->send     = btmtkuart_send_frame;
	SET_HCIDEV_DEV(hdev, &serdev->dev);

	hdev->manufacturer = 70;
	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);

	if (hci_register_dev(hdev) < 0) {
		dev_err(&serdev->dev, "Can't register HCI device\n");
		hci_free_dev(hdev);
		return -ENODEV;
	}

	return 0;
}

static void btmtkuart_remove(struct serdev_device *serdev)
{
	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
	struct hci_dev *hdev = bdev->hdev;

	hci_unregister_dev(hdev);
	hci_free_dev(hdev);
}

#ifdef CONFIG_OF
static const struct of_device_id mtk_of_match_table[] = {
	{ .compatible = "mediatek,mt7622-bluetooth"},
	{ }
};
MODULE_DEVICE_TABLE(of, mtk_of_match_table);
#endif

static struct serdev_device_driver btmtkuart_driver = {
	.probe = btmtkuart_probe,
	.remove = btmtkuart_remove,
	.driver = {
		.name = "btmtkuart",
		.of_match_table = of_match_ptr(mtk_of_match_table),
	},
};

module_serdev_device_driver(btmtkuart_driver);

MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_DESCRIPTION("MediaTek Bluetooth Serial driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_FIRMWARE(FIRMWARE_MT7622);