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