1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * Bluetooth HCI Three-wire UART driver
5 *
6 * Copyright (C) 2012 Intel Corporation
7 */
8
9 #include <linux/acpi.h>
10 #include <linux/errno.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/kernel.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/of_device.h>
15 #include <linux/serdev.h>
16 #include <linux/skbuff.h>
17
18 #include <net/bluetooth/bluetooth.h>
19 #include <net/bluetooth/hci_core.h>
20
21 #include "btrtl.h"
22 #include "hci_uart.h"
23
24 #define HCI_3WIRE_ACK_PKT 0
25 #define HCI_3WIRE_LINK_PKT 15
26
27 /* Sliding window size */
28 #define H5_TX_WIN_MAX 4
29
30 #define H5_ACK_TIMEOUT msecs_to_jiffies(250)
31 #define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
32
33 /*
34 * Maximum Three-wire packet:
35 * 4 byte header + max value for 12-bit length + 2 bytes for CRC
36 */
37 #define H5_MAX_LEN (4 + 0xfff + 2)
38
39 /* Convenience macros for reading Three-wire header values */
40 #define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07)
41 #define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07)
42 #define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01)
43 #define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01)
44 #define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f)
45 #define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0x0f) + ((hdr)[2] << 4))
46
47 #define SLIP_DELIMITER 0xc0
48 #define SLIP_ESC 0xdb
49 #define SLIP_ESC_DELIM 0xdc
50 #define SLIP_ESC_ESC 0xdd
51
52 /* H5 state flags */
53 enum {
54 H5_RX_ESC, /* SLIP escape mode */
55 H5_TX_ACK_REQ, /* Pending ack to send */
56 };
57
58 struct h5 {
59 /* Must be the first member, hci_serdev.c expects this. */
60 struct hci_uart serdev_hu;
61
62 struct sk_buff_head unack; /* Unack'ed packets queue */
63 struct sk_buff_head rel; /* Reliable packets queue */
64 struct sk_buff_head unrel; /* Unreliable packets queue */
65
66 unsigned long flags;
67
68 struct sk_buff *rx_skb; /* Receive buffer */
69 size_t rx_pending; /* Expecting more bytes */
70 u8 rx_ack; /* Last ack number received */
71
72 int (*rx_func)(struct hci_uart *hu, u8 c);
73
74 struct timer_list timer; /* Retransmission timer */
75 struct hci_uart *hu; /* Parent HCI UART */
76
77 u8 tx_seq; /* Next seq number to send */
78 u8 tx_ack; /* Next ack number to send */
79 u8 tx_win; /* Sliding window size */
80
81 enum {
82 H5_UNINITIALIZED,
83 H5_INITIALIZED,
84 H5_ACTIVE,
85 } state;
86
87 enum {
88 H5_AWAKE,
89 H5_SLEEPING,
90 H5_WAKING_UP,
91 } sleep;
92
93 const struct h5_vnd *vnd;
94 const char *id;
95
96 struct gpio_desc *enable_gpio;
97 struct gpio_desc *device_wake_gpio;
98 };
99
100 struct h5_vnd {
101 int (*setup)(struct h5 *h5);
102 void (*open)(struct h5 *h5);
103 void (*close)(struct h5 *h5);
104 int (*suspend)(struct h5 *h5);
105 int (*resume)(struct h5 *h5);
106 const struct acpi_gpio_mapping *acpi_gpio_map;
107 };
108
109 static void h5_reset_rx(struct h5 *h5);
110
h5_link_control(struct hci_uart * hu,const void * data,size_t len)111 static void h5_link_control(struct hci_uart *hu, const void *data, size_t len)
112 {
113 struct h5 *h5 = hu->priv;
114 struct sk_buff *nskb;
115
116 nskb = alloc_skb(3, GFP_ATOMIC);
117 if (!nskb)
118 return;
119
120 hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT;
121
122 skb_put_data(nskb, data, len);
123
124 skb_queue_tail(&h5->unrel, nskb);
125 }
126
h5_cfg_field(struct h5 * h5)127 static u8 h5_cfg_field(struct h5 *h5)
128 {
129 /* Sliding window size (first 3 bits) */
130 return h5->tx_win & 0x07;
131 }
132
h5_timed_event(struct timer_list * t)133 static void h5_timed_event(struct timer_list *t)
134 {
135 const unsigned char sync_req[] = { 0x01, 0x7e };
136 unsigned char conf_req[3] = { 0x03, 0xfc };
137 struct h5 *h5 = from_timer(h5, t, timer);
138 struct hci_uart *hu = h5->hu;
139 struct sk_buff *skb;
140 unsigned long flags;
141
142 BT_DBG("%s", hu->hdev->name);
143
144 if (h5->state == H5_UNINITIALIZED)
145 h5_link_control(hu, sync_req, sizeof(sync_req));
146
147 if (h5->state == H5_INITIALIZED) {
148 conf_req[2] = h5_cfg_field(h5);
149 h5_link_control(hu, conf_req, sizeof(conf_req));
150 }
151
152 if (h5->state != H5_ACTIVE) {
153 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
154 goto wakeup;
155 }
156
157 if (h5->sleep != H5_AWAKE) {
158 h5->sleep = H5_SLEEPING;
159 goto wakeup;
160 }
161
162 BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
163
164 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
165
166 while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
167 h5->tx_seq = (h5->tx_seq - 1) & 0x07;
168 skb_queue_head(&h5->rel, skb);
169 }
170
171 spin_unlock_irqrestore(&h5->unack.lock, flags);
172
173 wakeup:
174 hci_uart_tx_wakeup(hu);
175 }
176
h5_peer_reset(struct hci_uart * hu)177 static void h5_peer_reset(struct hci_uart *hu)
178 {
179 struct h5 *h5 = hu->priv;
180
181 bt_dev_err(hu->hdev, "Peer device has reset");
182
183 h5->state = H5_UNINITIALIZED;
184
185 del_timer(&h5->timer);
186
187 skb_queue_purge(&h5->rel);
188 skb_queue_purge(&h5->unrel);
189 skb_queue_purge(&h5->unack);
190
191 h5->tx_seq = 0;
192 h5->tx_ack = 0;
193
194 /* Send reset request to upper stack */
195 hci_reset_dev(hu->hdev);
196 }
197
h5_open(struct hci_uart * hu)198 static int h5_open(struct hci_uart *hu)
199 {
200 struct h5 *h5;
201 const unsigned char sync[] = { 0x01, 0x7e };
202
203 BT_DBG("hu %p", hu);
204
205 if (hu->serdev) {
206 h5 = serdev_device_get_drvdata(hu->serdev);
207 } else {
208 h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
209 if (!h5)
210 return -ENOMEM;
211 }
212
213 hu->priv = h5;
214 h5->hu = hu;
215
216 skb_queue_head_init(&h5->unack);
217 skb_queue_head_init(&h5->rel);
218 skb_queue_head_init(&h5->unrel);
219
220 h5_reset_rx(h5);
221
222 timer_setup(&h5->timer, h5_timed_event, 0);
223
224 h5->tx_win = H5_TX_WIN_MAX;
225
226 if (h5->vnd && h5->vnd->open)
227 h5->vnd->open(h5);
228
229 set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
230
231 /* Send initial sync request */
232 h5_link_control(hu, sync, sizeof(sync));
233 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
234
235 return 0;
236 }
237
h5_close(struct hci_uart * hu)238 static int h5_close(struct hci_uart *hu)
239 {
240 struct h5 *h5 = hu->priv;
241
242 del_timer_sync(&h5->timer);
243
244 skb_queue_purge(&h5->unack);
245 skb_queue_purge(&h5->rel);
246 skb_queue_purge(&h5->unrel);
247
248 kfree_skb(h5->rx_skb);
249 h5->rx_skb = NULL;
250
251 if (h5->vnd && h5->vnd->close)
252 h5->vnd->close(h5);
253
254 if (!hu->serdev)
255 kfree(h5);
256
257 return 0;
258 }
259
h5_setup(struct hci_uart * hu)260 static int h5_setup(struct hci_uart *hu)
261 {
262 struct h5 *h5 = hu->priv;
263
264 if (h5->vnd && h5->vnd->setup)
265 return h5->vnd->setup(h5);
266
267 return 0;
268 }
269
h5_pkt_cull(struct h5 * h5)270 static void h5_pkt_cull(struct h5 *h5)
271 {
272 struct sk_buff *skb, *tmp;
273 unsigned long flags;
274 int i, to_remove;
275 u8 seq;
276
277 spin_lock_irqsave(&h5->unack.lock, flags);
278
279 to_remove = skb_queue_len(&h5->unack);
280 if (to_remove == 0)
281 goto unlock;
282
283 seq = h5->tx_seq;
284
285 while (to_remove > 0) {
286 if (h5->rx_ack == seq)
287 break;
288
289 to_remove--;
290 seq = (seq - 1) & 0x07;
291 }
292
293 if (seq != h5->rx_ack)
294 BT_ERR("Controller acked invalid packet");
295
296 i = 0;
297 skb_queue_walk_safe(&h5->unack, skb, tmp) {
298 if (i++ >= to_remove)
299 break;
300
301 __skb_unlink(skb, &h5->unack);
302 dev_kfree_skb_irq(skb);
303 }
304
305 if (skb_queue_empty(&h5->unack))
306 del_timer(&h5->timer);
307
308 unlock:
309 spin_unlock_irqrestore(&h5->unack.lock, flags);
310 }
311
h5_handle_internal_rx(struct hci_uart * hu)312 static void h5_handle_internal_rx(struct hci_uart *hu)
313 {
314 struct h5 *h5 = hu->priv;
315 const unsigned char sync_req[] = { 0x01, 0x7e };
316 const unsigned char sync_rsp[] = { 0x02, 0x7d };
317 unsigned char conf_req[3] = { 0x03, 0xfc };
318 const unsigned char conf_rsp[] = { 0x04, 0x7b };
319 const unsigned char wakeup_req[] = { 0x05, 0xfa };
320 const unsigned char woken_req[] = { 0x06, 0xf9 };
321 const unsigned char sleep_req[] = { 0x07, 0x78 };
322 const unsigned char *hdr = h5->rx_skb->data;
323 const unsigned char *data = &h5->rx_skb->data[4];
324
325 BT_DBG("%s", hu->hdev->name);
326
327 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
328 return;
329
330 if (H5_HDR_LEN(hdr) < 2)
331 return;
332
333 conf_req[2] = h5_cfg_field(h5);
334
335 if (memcmp(data, sync_req, 2) == 0) {
336 if (h5->state == H5_ACTIVE)
337 h5_peer_reset(hu);
338 h5_link_control(hu, sync_rsp, 2);
339 } else if (memcmp(data, sync_rsp, 2) == 0) {
340 if (h5->state == H5_ACTIVE)
341 h5_peer_reset(hu);
342 h5->state = H5_INITIALIZED;
343 h5_link_control(hu, conf_req, 3);
344 } else if (memcmp(data, conf_req, 2) == 0) {
345 h5_link_control(hu, conf_rsp, 2);
346 h5_link_control(hu, conf_req, 3);
347 } else if (memcmp(data, conf_rsp, 2) == 0) {
348 if (H5_HDR_LEN(hdr) > 2)
349 h5->tx_win = (data[2] & 0x07);
350 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
351 h5->state = H5_ACTIVE;
352 hci_uart_init_ready(hu);
353 return;
354 } else if (memcmp(data, sleep_req, 2) == 0) {
355 BT_DBG("Peer went to sleep");
356 h5->sleep = H5_SLEEPING;
357 return;
358 } else if (memcmp(data, woken_req, 2) == 0) {
359 BT_DBG("Peer woke up");
360 h5->sleep = H5_AWAKE;
361 } else if (memcmp(data, wakeup_req, 2) == 0) {
362 BT_DBG("Peer requested wakeup");
363 h5_link_control(hu, woken_req, 2);
364 h5->sleep = H5_AWAKE;
365 } else {
366 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
367 return;
368 }
369
370 hci_uart_tx_wakeup(hu);
371 }
372
h5_complete_rx_pkt(struct hci_uart * hu)373 static void h5_complete_rx_pkt(struct hci_uart *hu)
374 {
375 struct h5 *h5 = hu->priv;
376 const unsigned char *hdr = h5->rx_skb->data;
377
378 if (H5_HDR_RELIABLE(hdr)) {
379 h5->tx_ack = (h5->tx_ack + 1) % 8;
380 set_bit(H5_TX_ACK_REQ, &h5->flags);
381 hci_uart_tx_wakeup(hu);
382 }
383
384 h5->rx_ack = H5_HDR_ACK(hdr);
385
386 h5_pkt_cull(h5);
387
388 switch (H5_HDR_PKT_TYPE(hdr)) {
389 case HCI_EVENT_PKT:
390 case HCI_ACLDATA_PKT:
391 case HCI_SCODATA_PKT:
392 case HCI_ISODATA_PKT:
393 hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr);
394
395 /* Remove Three-wire header */
396 skb_pull(h5->rx_skb, 4);
397
398 hci_recv_frame(hu->hdev, h5->rx_skb);
399 h5->rx_skb = NULL;
400
401 break;
402
403 default:
404 h5_handle_internal_rx(hu);
405 break;
406 }
407
408 h5_reset_rx(h5);
409 }
410
h5_rx_crc(struct hci_uart * hu,unsigned char c)411 static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
412 {
413 h5_complete_rx_pkt(hu);
414
415 return 0;
416 }
417
h5_rx_payload(struct hci_uart * hu,unsigned char c)418 static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
419 {
420 struct h5 *h5 = hu->priv;
421 const unsigned char *hdr = h5->rx_skb->data;
422
423 if (H5_HDR_CRC(hdr)) {
424 h5->rx_func = h5_rx_crc;
425 h5->rx_pending = 2;
426 } else {
427 h5_complete_rx_pkt(hu);
428 }
429
430 return 0;
431 }
432
h5_rx_3wire_hdr(struct hci_uart * hu,unsigned char c)433 static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
434 {
435 struct h5 *h5 = hu->priv;
436 const unsigned char *hdr = h5->rx_skb->data;
437
438 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
439 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
440 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
441 H5_HDR_LEN(hdr));
442
443 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
444 bt_dev_err(hu->hdev, "Invalid header checksum");
445 h5_reset_rx(h5);
446 return 0;
447 }
448
449 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
450 bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)",
451 H5_HDR_SEQ(hdr), h5->tx_ack);
452 h5_reset_rx(h5);
453 return 0;
454 }
455
456 if (h5->state != H5_ACTIVE &&
457 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
458 bt_dev_err(hu->hdev, "Non-link packet received in non-active state");
459 h5_reset_rx(h5);
460 return 0;
461 }
462
463 h5->rx_func = h5_rx_payload;
464 h5->rx_pending = H5_HDR_LEN(hdr);
465
466 return 0;
467 }
468
h5_rx_pkt_start(struct hci_uart * hu,unsigned char c)469 static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
470 {
471 struct h5 *h5 = hu->priv;
472
473 if (c == SLIP_DELIMITER)
474 return 1;
475
476 h5->rx_func = h5_rx_3wire_hdr;
477 h5->rx_pending = 4;
478
479 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
480 if (!h5->rx_skb) {
481 bt_dev_err(hu->hdev, "Can't allocate mem for new packet");
482 h5_reset_rx(h5);
483 return -ENOMEM;
484 }
485
486 h5->rx_skb->dev = (void *)hu->hdev;
487
488 return 0;
489 }
490
h5_rx_delimiter(struct hci_uart * hu,unsigned char c)491 static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
492 {
493 struct h5 *h5 = hu->priv;
494
495 if (c == SLIP_DELIMITER)
496 h5->rx_func = h5_rx_pkt_start;
497
498 return 1;
499 }
500
h5_unslip_one_byte(struct h5 * h5,unsigned char c)501 static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
502 {
503 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
504 const u8 *byte = &c;
505
506 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
507 set_bit(H5_RX_ESC, &h5->flags);
508 return;
509 }
510
511 if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
512 switch (c) {
513 case SLIP_ESC_DELIM:
514 byte = &delim;
515 break;
516 case SLIP_ESC_ESC:
517 byte = &esc;
518 break;
519 default:
520 BT_ERR("Invalid esc byte 0x%02hhx", c);
521 h5_reset_rx(h5);
522 return;
523 }
524 }
525
526 skb_put_data(h5->rx_skb, byte, 1);
527 h5->rx_pending--;
528
529 BT_DBG("unslipped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
530 }
531
h5_reset_rx(struct h5 * h5)532 static void h5_reset_rx(struct h5 *h5)
533 {
534 if (h5->rx_skb) {
535 kfree_skb(h5->rx_skb);
536 h5->rx_skb = NULL;
537 }
538
539 h5->rx_func = h5_rx_delimiter;
540 h5->rx_pending = 0;
541 clear_bit(H5_RX_ESC, &h5->flags);
542 }
543
h5_recv(struct hci_uart * hu,const void * data,int count)544 static int h5_recv(struct hci_uart *hu, const void *data, int count)
545 {
546 struct h5 *h5 = hu->priv;
547 const unsigned char *ptr = data;
548
549 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
550 count);
551
552 while (count > 0) {
553 int processed;
554
555 if (h5->rx_pending > 0) {
556 if (*ptr == SLIP_DELIMITER) {
557 bt_dev_err(hu->hdev, "Too short H5 packet");
558 h5_reset_rx(h5);
559 continue;
560 }
561
562 h5_unslip_one_byte(h5, *ptr);
563
564 ptr++; count--;
565 continue;
566 }
567
568 processed = h5->rx_func(hu, *ptr);
569 if (processed < 0)
570 return processed;
571
572 ptr += processed;
573 count -= processed;
574 }
575
576 return 0;
577 }
578
h5_enqueue(struct hci_uart * hu,struct sk_buff * skb)579 static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
580 {
581 struct h5 *h5 = hu->priv;
582
583 if (skb->len > 0xfff) {
584 bt_dev_err(hu->hdev, "Packet too long (%u bytes)", skb->len);
585 kfree_skb(skb);
586 return 0;
587 }
588
589 if (h5->state != H5_ACTIVE) {
590 bt_dev_err(hu->hdev, "Ignoring HCI data in non-active state");
591 kfree_skb(skb);
592 return 0;
593 }
594
595 switch (hci_skb_pkt_type(skb)) {
596 case HCI_ACLDATA_PKT:
597 case HCI_COMMAND_PKT:
598 skb_queue_tail(&h5->rel, skb);
599 break;
600
601 case HCI_SCODATA_PKT:
602 case HCI_ISODATA_PKT:
603 skb_queue_tail(&h5->unrel, skb);
604 break;
605
606 default:
607 bt_dev_err(hu->hdev, "Unknown packet type %u", hci_skb_pkt_type(skb));
608 kfree_skb(skb);
609 break;
610 }
611
612 return 0;
613 }
614
h5_slip_delim(struct sk_buff * skb)615 static void h5_slip_delim(struct sk_buff *skb)
616 {
617 const char delim = SLIP_DELIMITER;
618
619 skb_put_data(skb, &delim, 1);
620 }
621
h5_slip_one_byte(struct sk_buff * skb,u8 c)622 static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
623 {
624 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
625 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
626
627 switch (c) {
628 case SLIP_DELIMITER:
629 skb_put_data(skb, &esc_delim, 2);
630 break;
631 case SLIP_ESC:
632 skb_put_data(skb, &esc_esc, 2);
633 break;
634 default:
635 skb_put_data(skb, &c, 1);
636 }
637 }
638
valid_packet_type(u8 type)639 static bool valid_packet_type(u8 type)
640 {
641 switch (type) {
642 case HCI_ACLDATA_PKT:
643 case HCI_COMMAND_PKT:
644 case HCI_SCODATA_PKT:
645 case HCI_ISODATA_PKT:
646 case HCI_3WIRE_LINK_PKT:
647 case HCI_3WIRE_ACK_PKT:
648 return true;
649 default:
650 return false;
651 }
652 }
653
h5_prepare_pkt(struct hci_uart * hu,u8 pkt_type,const u8 * data,size_t len)654 static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
655 const u8 *data, size_t len)
656 {
657 struct h5 *h5 = hu->priv;
658 struct sk_buff *nskb;
659 u8 hdr[4];
660 int i;
661
662 if (!valid_packet_type(pkt_type)) {
663 bt_dev_err(hu->hdev, "Unknown packet type %u", pkt_type);
664 return NULL;
665 }
666
667 /*
668 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
669 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
670 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
671 * delimiters at start and end).
672 */
673 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
674 if (!nskb)
675 return NULL;
676
677 hci_skb_pkt_type(nskb) = pkt_type;
678
679 h5_slip_delim(nskb);
680
681 hdr[0] = h5->tx_ack << 3;
682 clear_bit(H5_TX_ACK_REQ, &h5->flags);
683
684 /* Reliable packet? */
685 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
686 hdr[0] |= 1 << 7;
687 hdr[0] |= h5->tx_seq;
688 h5->tx_seq = (h5->tx_seq + 1) % 8;
689 }
690
691 hdr[1] = pkt_type | ((len & 0x0f) << 4);
692 hdr[2] = len >> 4;
693 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
694
695 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
696 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
697 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
698 H5_HDR_LEN(hdr));
699
700 for (i = 0; i < 4; i++)
701 h5_slip_one_byte(nskb, hdr[i]);
702
703 for (i = 0; i < len; i++)
704 h5_slip_one_byte(nskb, data[i]);
705
706 h5_slip_delim(nskb);
707
708 return nskb;
709 }
710
h5_dequeue(struct hci_uart * hu)711 static struct sk_buff *h5_dequeue(struct hci_uart *hu)
712 {
713 struct h5 *h5 = hu->priv;
714 unsigned long flags;
715 struct sk_buff *skb, *nskb;
716
717 if (h5->sleep != H5_AWAKE) {
718 const unsigned char wakeup_req[] = { 0x05, 0xfa };
719
720 if (h5->sleep == H5_WAKING_UP)
721 return NULL;
722
723 h5->sleep = H5_WAKING_UP;
724 BT_DBG("Sending wakeup request");
725
726 mod_timer(&h5->timer, jiffies + HZ / 100);
727 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
728 }
729
730 skb = skb_dequeue(&h5->unrel);
731 if (skb) {
732 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
733 skb->data, skb->len);
734 if (nskb) {
735 kfree_skb(skb);
736 return nskb;
737 }
738
739 skb_queue_head(&h5->unrel, skb);
740 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
741 }
742
743 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
744
745 if (h5->unack.qlen >= h5->tx_win)
746 goto unlock;
747
748 skb = skb_dequeue(&h5->rel);
749 if (skb) {
750 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
751 skb->data, skb->len);
752 if (nskb) {
753 __skb_queue_tail(&h5->unack, skb);
754 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
755 spin_unlock_irqrestore(&h5->unack.lock, flags);
756 return nskb;
757 }
758
759 skb_queue_head(&h5->rel, skb);
760 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
761 }
762
763 unlock:
764 spin_unlock_irqrestore(&h5->unack.lock, flags);
765
766 if (test_bit(H5_TX_ACK_REQ, &h5->flags))
767 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
768
769 return NULL;
770 }
771
h5_flush(struct hci_uart * hu)772 static int h5_flush(struct hci_uart *hu)
773 {
774 BT_DBG("hu %p", hu);
775 return 0;
776 }
777
778 static const struct hci_uart_proto h5p = {
779 .id = HCI_UART_3WIRE,
780 .name = "Three-wire (H5)",
781 .open = h5_open,
782 .close = h5_close,
783 .setup = h5_setup,
784 .recv = h5_recv,
785 .enqueue = h5_enqueue,
786 .dequeue = h5_dequeue,
787 .flush = h5_flush,
788 };
789
h5_serdev_probe(struct serdev_device * serdev)790 static int h5_serdev_probe(struct serdev_device *serdev)
791 {
792 struct device *dev = &serdev->dev;
793 struct h5 *h5;
794
795 h5 = devm_kzalloc(dev, sizeof(*h5), GFP_KERNEL);
796 if (!h5)
797 return -ENOMEM;
798
799 h5->hu = &h5->serdev_hu;
800 h5->serdev_hu.serdev = serdev;
801 serdev_device_set_drvdata(serdev, h5);
802
803 if (has_acpi_companion(dev)) {
804 const struct acpi_device_id *match;
805
806 match = acpi_match_device(dev->driver->acpi_match_table, dev);
807 if (!match)
808 return -ENODEV;
809
810 h5->vnd = (const struct h5_vnd *)match->driver_data;
811 h5->id = (char *)match->id;
812
813 if (h5->vnd->acpi_gpio_map)
814 devm_acpi_dev_add_driver_gpios(dev,
815 h5->vnd->acpi_gpio_map);
816 } else {
817 const void *data;
818
819 data = of_device_get_match_data(dev);
820 if (!data)
821 return -ENODEV;
822
823 h5->vnd = (const struct h5_vnd *)data;
824 }
825
826
827 h5->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
828 if (IS_ERR(h5->enable_gpio))
829 return PTR_ERR(h5->enable_gpio);
830
831 h5->device_wake_gpio = devm_gpiod_get_optional(dev, "device-wake",
832 GPIOD_OUT_LOW);
833 if (IS_ERR(h5->device_wake_gpio))
834 return PTR_ERR(h5->device_wake_gpio);
835
836 return hci_uart_register_device(&h5->serdev_hu, &h5p);
837 }
838
h5_serdev_remove(struct serdev_device * serdev)839 static void h5_serdev_remove(struct serdev_device *serdev)
840 {
841 struct h5 *h5 = serdev_device_get_drvdata(serdev);
842
843 hci_uart_unregister_device(&h5->serdev_hu);
844 }
845
h5_serdev_suspend(struct device * dev)846 static int __maybe_unused h5_serdev_suspend(struct device *dev)
847 {
848 struct h5 *h5 = dev_get_drvdata(dev);
849 int ret = 0;
850
851 if (h5->vnd && h5->vnd->suspend)
852 ret = h5->vnd->suspend(h5);
853
854 return ret;
855 }
856
h5_serdev_resume(struct device * dev)857 static int __maybe_unused h5_serdev_resume(struct device *dev)
858 {
859 struct h5 *h5 = dev_get_drvdata(dev);
860 int ret = 0;
861
862 if (h5->vnd && h5->vnd->resume)
863 ret = h5->vnd->resume(h5);
864
865 return ret;
866 }
867
868 #ifdef CONFIG_BT_HCIUART_RTL
h5_btrtl_setup(struct h5 * h5)869 static int h5_btrtl_setup(struct h5 *h5)
870 {
871 struct btrtl_device_info *btrtl_dev;
872 struct sk_buff *skb;
873 __le32 baudrate_data;
874 u32 device_baudrate;
875 unsigned int controller_baudrate;
876 bool flow_control;
877 int err;
878
879 btrtl_dev = btrtl_initialize(h5->hu->hdev, h5->id);
880 if (IS_ERR(btrtl_dev))
881 return PTR_ERR(btrtl_dev);
882
883 err = btrtl_get_uart_settings(h5->hu->hdev, btrtl_dev,
884 &controller_baudrate, &device_baudrate,
885 &flow_control);
886 if (err)
887 goto out_free;
888
889 baudrate_data = cpu_to_le32(device_baudrate);
890 skb = __hci_cmd_sync(h5->hu->hdev, 0xfc17, sizeof(baudrate_data),
891 &baudrate_data, HCI_INIT_TIMEOUT);
892 if (IS_ERR(skb)) {
893 rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n");
894 err = PTR_ERR(skb);
895 goto out_free;
896 } else {
897 kfree_skb(skb);
898 }
899 /* Give the device some time to set up the new baudrate. */
900 usleep_range(10000, 20000);
901
902 serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate);
903 serdev_device_set_flow_control(h5->hu->serdev, flow_control);
904
905 err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev);
906 /* Give the device some time before the hci-core sends it a reset */
907 usleep_range(10000, 20000);
908
909 /* Enable controller to do both LE scan and BR/EDR inquiry
910 * simultaneously.
911 */
912 set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &h5->hu->hdev->quirks);
913
914 out_free:
915 btrtl_free(btrtl_dev);
916
917 return err;
918 }
919
h5_btrtl_open(struct h5 * h5)920 static void h5_btrtl_open(struct h5 *h5)
921 {
922 /* Devices always start with these fixed parameters */
923 serdev_device_set_flow_control(h5->hu->serdev, false);
924 serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN);
925 serdev_device_set_baudrate(h5->hu->serdev, 115200);
926
927 /* The controller needs up to 500ms to wakeup */
928 gpiod_set_value_cansleep(h5->enable_gpio, 1);
929 gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
930 msleep(500);
931 }
932
h5_btrtl_close(struct h5 * h5)933 static void h5_btrtl_close(struct h5 *h5)
934 {
935 gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
936 gpiod_set_value_cansleep(h5->enable_gpio, 0);
937 }
938
939 /* Suspend/resume support. On many devices the RTL BT device loses power during
940 * suspend/resume, causing it to lose its firmware and all state. So we simply
941 * turn it off on suspend and reprobe on resume. This mirrors how RTL devices
942 * are handled in the USB driver, where the USB_QUIRK_RESET_RESUME is used which
943 * also causes a reprobe on resume.
944 */
h5_btrtl_suspend(struct h5 * h5)945 static int h5_btrtl_suspend(struct h5 *h5)
946 {
947 serdev_device_set_flow_control(h5->hu->serdev, false);
948 gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
949 gpiod_set_value_cansleep(h5->enable_gpio, 0);
950 return 0;
951 }
952
953 struct h5_btrtl_reprobe {
954 struct device *dev;
955 struct work_struct work;
956 };
957
h5_btrtl_reprobe_worker(struct work_struct * work)958 static void h5_btrtl_reprobe_worker(struct work_struct *work)
959 {
960 struct h5_btrtl_reprobe *reprobe =
961 container_of(work, struct h5_btrtl_reprobe, work);
962 int ret;
963
964 ret = device_reprobe(reprobe->dev);
965 if (ret && ret != -EPROBE_DEFER)
966 dev_err(reprobe->dev, "Reprobe error %d\n", ret);
967
968 put_device(reprobe->dev);
969 kfree(reprobe);
970 module_put(THIS_MODULE);
971 }
972
h5_btrtl_resume(struct h5 * h5)973 static int h5_btrtl_resume(struct h5 *h5)
974 {
975 struct h5_btrtl_reprobe *reprobe;
976
977 reprobe = kzalloc(sizeof(*reprobe), GFP_KERNEL);
978 if (!reprobe)
979 return -ENOMEM;
980
981 __module_get(THIS_MODULE);
982
983 INIT_WORK(&reprobe->work, h5_btrtl_reprobe_worker);
984 reprobe->dev = get_device(&h5->hu->serdev->dev);
985 queue_work(system_long_wq, &reprobe->work);
986 return 0;
987 }
988
989 static const struct acpi_gpio_params btrtl_device_wake_gpios = { 0, 0, false };
990 static const struct acpi_gpio_params btrtl_enable_gpios = { 1, 0, false };
991 static const struct acpi_gpio_params btrtl_host_wake_gpios = { 2, 0, false };
992 static const struct acpi_gpio_mapping acpi_btrtl_gpios[] = {
993 { "device-wake-gpios", &btrtl_device_wake_gpios, 1 },
994 { "enable-gpios", &btrtl_enable_gpios, 1 },
995 { "host-wake-gpios", &btrtl_host_wake_gpios, 1 },
996 {},
997 };
998
999 static struct h5_vnd rtl_vnd = {
1000 .setup = h5_btrtl_setup,
1001 .open = h5_btrtl_open,
1002 .close = h5_btrtl_close,
1003 .suspend = h5_btrtl_suspend,
1004 .resume = h5_btrtl_resume,
1005 .acpi_gpio_map = acpi_btrtl_gpios,
1006 };
1007 #endif
1008
1009 #ifdef CONFIG_ACPI
1010 static const struct acpi_device_id h5_acpi_match[] = {
1011 #ifdef CONFIG_BT_HCIUART_RTL
1012 { "OBDA8723", (kernel_ulong_t)&rtl_vnd },
1013 #endif
1014 { },
1015 };
1016 MODULE_DEVICE_TABLE(acpi, h5_acpi_match);
1017 #endif
1018
1019 static const struct dev_pm_ops h5_serdev_pm_ops = {
1020 SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume)
1021 };
1022
1023 static const struct of_device_id rtl_bluetooth_of_match[] = {
1024 #ifdef CONFIG_BT_HCIUART_RTL
1025 { .compatible = "realtek,rtl8822cs-bt",
1026 .data = (const void *)&rtl_vnd },
1027 { .compatible = "realtek,rtl8723bs-bt",
1028 .data = (const void *)&rtl_vnd },
1029 #endif
1030 { },
1031 };
1032 MODULE_DEVICE_TABLE(of, rtl_bluetooth_of_match);
1033
1034 static struct serdev_device_driver h5_serdev_driver = {
1035 .probe = h5_serdev_probe,
1036 .remove = h5_serdev_remove,
1037 .driver = {
1038 .name = "hci_uart_h5",
1039 .acpi_match_table = ACPI_PTR(h5_acpi_match),
1040 .pm = &h5_serdev_pm_ops,
1041 .of_match_table = rtl_bluetooth_of_match,
1042 },
1043 };
1044
h5_init(void)1045 int __init h5_init(void)
1046 {
1047 serdev_device_driver_register(&h5_serdev_driver);
1048 return hci_uart_register_proto(&h5p);
1049 }
1050
h5_deinit(void)1051 int __exit h5_deinit(void)
1052 {
1053 serdev_device_driver_unregister(&h5_serdev_driver);
1054 return hci_uart_unregister_proto(&h5p);
1055 }
1056