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/bitrev.h>
11#include <linux/crc-ccitt.h>
12#include <linux/errno.h>
13#include <linux/gpio/consumer.h>
14#include <linux/kernel.h>
15#include <linux/mod_devicetable.h>
16#include <linux/of.h>
17#include <linux/pm_runtime.h>
18#include <linux/serdev.h>
19#include <linux/skbuff.h>
20
21#include <net/bluetooth/bluetooth.h>
22#include <net/bluetooth/hci_core.h>
23
24#include "btrtl.h"
25#include "hci_uart.h"
26
27#define SUSPEND_TIMEOUT_MS 6000
28
29#define HCI_3WIRE_ACK_PKT 0
30#define HCI_3WIRE_LINK_PKT 15
31
32/* Sliding window size */
33#define H5_TX_WIN_MAX 4
34
35#define H5_ACK_TIMEOUT msecs_to_jiffies(250)
36#define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
37
38/*
39 * Maximum Three-wire packet:
40 * 4 byte header + max value for 12-bit length + 2 bytes for CRC
41 */
42#define H5_MAX_LEN (4 + 0xfff + 2)
43
44/* Convenience macros for reading Three-wire header values */
45#define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07)
46#define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07)
47#define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01)
48#define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01)
49#define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f)
50#define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0x0f) + ((hdr)[2] << 4))
51
52#define SLIP_DELIMITER 0xc0
53#define SLIP_ESC 0xdb
54#define SLIP_ESC_DELIM 0xdc
55#define SLIP_ESC_ESC 0xdd
56
57/* H5 state flags */
58enum {
59 H5_RX_ESC, /* SLIP escape mode */
60 H5_TX_ACK_REQ, /* Pending ack to send */
61 H5_WAKEUP_DISABLE, /* Device cannot wake host */
62 H5_HW_FLOW_CONTROL, /* Use HW flow control */
63 H5_CRC, /* Use CRC */
64};
65
66struct h5 {
67 /* Must be the first member, hci_serdev.c expects this. */
68 struct hci_uart serdev_hu;
69
70 struct sk_buff_head unack; /* Unack'ed packets queue */
71 struct sk_buff_head rel; /* Reliable packets queue */
72 struct sk_buff_head unrel; /* Unreliable packets queue */
73
74 unsigned long flags;
75
76 struct sk_buff *rx_skb; /* Receive buffer */
77 size_t rx_pending; /* Expecting more bytes */
78 u8 rx_ack; /* Last ack number received */
79
80 int (*rx_func)(struct hci_uart *hu, u8 c);
81
82 struct timer_list timer; /* Retransmission timer */
83 struct hci_uart *hu; /* Parent HCI UART */
84
85 u8 tx_seq; /* Next seq number to send */
86 u8 tx_ack; /* Next ack number to send */
87 u8 tx_win; /* Sliding window size */
88
89 enum {
90 H5_UNINITIALIZED,
91 H5_INITIALIZED,
92 H5_ACTIVE,
93 } state;
94
95 enum {
96 H5_AWAKE,
97 H5_SLEEPING,
98 H5_WAKING_UP,
99 } sleep;
100
101 const struct h5_vnd *vnd;
102 const char *id;
103
104 struct gpio_desc *enable_gpio;
105 struct gpio_desc *device_wake_gpio;
106};
107
108enum h5_driver_info {
109 H5_INFO_WAKEUP_DISABLE = BIT(0),
110};
111
112struct h5_vnd {
113 int (*setup)(struct h5 *h5);
114 void (*open)(struct h5 *h5);
115 void (*close)(struct h5 *h5);
116 int (*suspend)(struct h5 *h5);
117 int (*resume)(struct h5 *h5);
118 const struct acpi_gpio_mapping *acpi_gpio_map;
119 int sizeof_priv;
120};
121
122struct h5_device_data {
123 uint32_t driver_info;
124 struct h5_vnd *vnd;
125};
126
127static void h5_reset_rx(struct h5 *h5);
128
129static void h5_link_control(struct hci_uart *hu, const void *data, size_t len)
130{
131 struct h5 *h5 = hu->priv;
132 struct sk_buff *nskb;
133
134 nskb = alloc_skb(size: 3, GFP_ATOMIC);
135 if (!nskb)
136 return;
137
138 hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT;
139
140 skb_put_data(skb: nskb, data, len);
141
142 skb_queue_tail(list: &h5->unrel, newsk: nskb);
143}
144
145static u8 h5_cfg_field(struct h5 *h5)
146{
147 /* Sliding window size (first 3 bits) and CRC request (fifth bit). */
148 return (h5->tx_win & 0x07) | 0x10;
149}
150
151static void h5_timed_event(struct timer_list *t)
152{
153 const unsigned char sync_req[] = { 0x01, 0x7e };
154 unsigned char conf_req[3] = { 0x03, 0xfc };
155 struct h5 *h5 = timer_container_of(h5, t, timer);
156 struct hci_uart *hu = h5->hu;
157 struct sk_buff *skb;
158 unsigned long flags;
159
160 BT_DBG("%s", hu->hdev->name);
161
162 if (h5->state == H5_UNINITIALIZED)
163 h5_link_control(hu, data: sync_req, len: sizeof(sync_req));
164
165 if (h5->state == H5_INITIALIZED) {
166 conf_req[2] = h5_cfg_field(h5);
167 h5_link_control(hu, data: conf_req, len: sizeof(conf_req));
168 }
169
170 if (h5->state != H5_ACTIVE) {
171 mod_timer(timer: &h5->timer, expires: jiffies + H5_SYNC_TIMEOUT);
172 goto wakeup;
173 }
174
175 if (h5->sleep != H5_AWAKE) {
176 h5->sleep = H5_SLEEPING;
177 goto wakeup;
178 }
179
180 BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
181
182 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
183
184 while ((skb = __skb_dequeue_tail(list: &h5->unack)) != NULL) {
185 h5->tx_seq = (h5->tx_seq - 1) & 0x07;
186 skb_queue_head(list: &h5->rel, newsk: skb);
187 }
188
189 spin_unlock_irqrestore(lock: &h5->unack.lock, flags);
190
191wakeup:
192 hci_uart_tx_wakeup(hu);
193}
194
195static void h5_peer_reset(struct hci_uart *hu)
196{
197 struct h5 *h5 = hu->priv;
198
199 bt_dev_err(hu->hdev, "Peer device has reset");
200
201 h5->state = H5_UNINITIALIZED;
202
203 timer_delete(timer: &h5->timer);
204
205 skb_queue_purge(list: &h5->rel);
206 skb_queue_purge(list: &h5->unrel);
207 skb_queue_purge(list: &h5->unack);
208
209 h5->tx_seq = 0;
210 h5->tx_ack = 0;
211
212 /* Send reset request to upper stack */
213 hci_reset_dev(hdev: hu->hdev);
214}
215
216static int h5_open(struct hci_uart *hu)
217{
218 struct h5 *h5;
219
220 BT_DBG("hu %p", hu);
221
222 if (hu->serdev) {
223 h5 = serdev_device_get_drvdata(serdev: hu->serdev);
224 } else {
225 h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
226 if (!h5)
227 return -ENOMEM;
228 }
229
230 hu->priv = h5;
231 h5->hu = hu;
232
233 skb_queue_head_init(list: &h5->unack);
234 skb_queue_head_init(list: &h5->rel);
235 skb_queue_head_init(list: &h5->unrel);
236
237 h5_reset_rx(h5);
238
239 timer_setup(&h5->timer, h5_timed_event, 0);
240
241 h5->tx_win = H5_TX_WIN_MAX;
242
243 if (h5->vnd && h5->vnd->open)
244 h5->vnd->open(h5);
245
246 set_bit(HCI_UART_INIT_PENDING, addr: &hu->hdev_flags);
247
248 /*
249 * Wait one jiffy because the UART layer won't set HCI_UART_PROTO_READY,
250 * which allows us to send link packets, until this function returns.
251 */
252 mod_timer(timer: &h5->timer, expires: jiffies + 1);
253
254 return 0;
255}
256
257static int h5_close(struct hci_uart *hu)
258{
259 struct h5 *h5 = hu->priv;
260
261 timer_delete_sync(timer: &h5->timer);
262
263 skb_queue_purge(list: &h5->unack);
264 skb_queue_purge(list: &h5->rel);
265 skb_queue_purge(list: &h5->unrel);
266
267 kfree_skb(skb: h5->rx_skb);
268 h5->rx_skb = NULL;
269
270 if (h5->vnd && h5->vnd->close)
271 h5->vnd->close(h5);
272
273 if (!hu->serdev)
274 kfree(objp: h5);
275
276 return 0;
277}
278
279static int h5_setup(struct hci_uart *hu)
280{
281 struct h5 *h5 = hu->priv;
282
283 if (h5->vnd && h5->vnd->setup)
284 return h5->vnd->setup(h5);
285
286 return 0;
287}
288
289static void h5_pkt_cull(struct h5 *h5)
290{
291 struct sk_buff *skb, *tmp;
292 unsigned long flags;
293 int i, to_remove;
294 u8 seq;
295
296 spin_lock_irqsave(&h5->unack.lock, flags);
297
298 to_remove = skb_queue_len(list_: &h5->unack);
299 if (to_remove == 0)
300 goto unlock;
301
302 seq = h5->tx_seq;
303
304 while (to_remove > 0) {
305 if (h5->rx_ack == seq)
306 break;
307
308 to_remove--;
309 seq = (seq - 1) & 0x07;
310 }
311
312 if (seq != h5->rx_ack)
313 BT_ERR("Controller acked invalid packet");
314
315 i = 0;
316 skb_queue_walk_safe(&h5->unack, skb, tmp) {
317 if (i++ >= to_remove)
318 break;
319
320 __skb_unlink(skb, list: &h5->unack);
321 dev_kfree_skb_irq(skb);
322 }
323
324 if (skb_queue_empty(list: &h5->unack))
325 timer_delete(timer: &h5->timer);
326
327unlock:
328 spin_unlock_irqrestore(lock: &h5->unack.lock, flags);
329}
330
331static void h5_handle_internal_rx(struct hci_uart *hu)
332{
333 struct h5 *h5 = hu->priv;
334 const unsigned char sync_req[] = { 0x01, 0x7e };
335 const unsigned char sync_rsp[] = { 0x02, 0x7d };
336 unsigned char conf_req[3] = { 0x03, 0xfc };
337 const unsigned char conf_rsp[] = { 0x04, 0x7b };
338 const unsigned char wakeup_req[] = { 0x05, 0xfa };
339 const unsigned char woken_req[] = { 0x06, 0xf9 };
340 const unsigned char sleep_req[] = { 0x07, 0x78 };
341 const unsigned char *hdr = h5->rx_skb->data;
342 const unsigned char *data = &h5->rx_skb->data[4];
343
344 BT_DBG("%s", hu->hdev->name);
345
346 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
347 return;
348
349 if (H5_HDR_LEN(hdr) < 2)
350 return;
351
352 conf_req[2] = h5_cfg_field(h5);
353
354 if (memcmp(p: data, q: sync_req, size: 2) == 0) {
355 if (h5->state == H5_ACTIVE)
356 h5_peer_reset(hu);
357 h5_link_control(hu, data: sync_rsp, len: 2);
358 } else if (memcmp(p: data, q: sync_rsp, size: 2) == 0) {
359 if (h5->state == H5_ACTIVE)
360 h5_peer_reset(hu);
361 h5->state = H5_INITIALIZED;
362 h5_link_control(hu, data: conf_req, len: 3);
363 } else if (memcmp(p: data, q: conf_req, size: 2) == 0) {
364 h5_link_control(hu, data: conf_rsp, len: 2);
365 h5_link_control(hu, data: conf_req, len: 3);
366 } else if (memcmp(p: data, q: conf_rsp, size: 2) == 0) {
367 if (H5_HDR_LEN(hdr) > 2) {
368 h5->tx_win = (data[2] & 0x07);
369 assign_bit(H5_CRC, &h5->flags, data[2] & 0x10);
370 }
371 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
372 h5->state = H5_ACTIVE;
373 hci_uart_init_ready(hu);
374 return;
375 } else if (memcmp(p: data, q: sleep_req, size: 2) == 0) {
376 BT_DBG("Peer went to sleep");
377 h5->sleep = H5_SLEEPING;
378 return;
379 } else if (memcmp(p: data, q: woken_req, size: 2) == 0) {
380 BT_DBG("Peer woke up");
381 h5->sleep = H5_AWAKE;
382 } else if (memcmp(p: data, q: wakeup_req, size: 2) == 0) {
383 BT_DBG("Peer requested wakeup");
384 h5_link_control(hu, data: woken_req, len: 2);
385 h5->sleep = H5_AWAKE;
386 } else {
387 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
388 return;
389 }
390
391 hci_uart_tx_wakeup(hu);
392}
393
394static void h5_complete_rx_pkt(struct hci_uart *hu)
395{
396 struct h5 *h5 = hu->priv;
397 const unsigned char *hdr = h5->rx_skb->data;
398
399 if (H5_HDR_RELIABLE(hdr)) {
400 h5->tx_ack = (h5->tx_ack + 1) % 8;
401 set_bit(nr: H5_TX_ACK_REQ, addr: &h5->flags);
402 hci_uart_tx_wakeup(hu);
403 }
404
405 h5->rx_ack = H5_HDR_ACK(hdr);
406
407 h5_pkt_cull(h5);
408
409 switch (H5_HDR_PKT_TYPE(hdr)) {
410 case HCI_EVENT_PKT:
411 case HCI_ACLDATA_PKT:
412 case HCI_SCODATA_PKT:
413 case HCI_ISODATA_PKT:
414 hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr);
415
416 /* Remove Three-wire header */
417 skb_pull(skb: h5->rx_skb, len: 4);
418
419 hci_recv_frame(hdev: hu->hdev, skb: h5->rx_skb);
420 h5->rx_skb = NULL;
421
422 break;
423
424 default:
425 h5_handle_internal_rx(hu);
426 break;
427 }
428
429 h5_reset_rx(h5);
430}
431
432static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
433{
434 struct h5 *h5 = hu->priv;
435 const unsigned char *hdr = h5->rx_skb->data;
436 u16 crc;
437 __be16 crc_be;
438
439 crc = crc_ccitt(crc: 0xffff, buffer: hdr, len: 4 + H5_HDR_LEN(hdr));
440 crc = bitrev16(crc);
441
442 crc_be = cpu_to_be16(crc);
443
444 if (memcmp(p: &crc_be, q: hdr + 4 + H5_HDR_LEN(hdr), size: 2) != 0) {
445 bt_dev_err(hu->hdev, "Received packet with invalid CRC");
446 h5_reset_rx(h5);
447 } else {
448 /* Remove CRC bytes */
449 skb_trim(skb: h5->rx_skb, len: 4 + H5_HDR_LEN(hdr));
450 h5_complete_rx_pkt(hu);
451 }
452
453 return 0;
454}
455
456static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
457{
458 struct h5 *h5 = hu->priv;
459 const unsigned char *hdr = h5->rx_skb->data;
460
461 if (H5_HDR_CRC(hdr)) {
462 h5->rx_func = h5_rx_crc;
463 h5->rx_pending = 2;
464 } else {
465 h5_complete_rx_pkt(hu);
466 }
467
468 return 0;
469}
470
471static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
472{
473 struct h5 *h5 = hu->priv;
474 const unsigned char *hdr = h5->rx_skb->data;
475
476 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
477 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
478 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
479 H5_HDR_LEN(hdr));
480
481 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
482 bt_dev_err(hu->hdev, "Invalid header checksum");
483 h5_reset_rx(h5);
484 return 0;
485 }
486
487 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
488 bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)",
489 H5_HDR_SEQ(hdr), h5->tx_ack);
490 set_bit(nr: H5_TX_ACK_REQ, addr: &h5->flags);
491 hci_uart_tx_wakeup(hu);
492 h5_reset_rx(h5);
493 return 0;
494 }
495
496 if (h5->state != H5_ACTIVE &&
497 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
498 bt_dev_err(hu->hdev, "Non-link packet received in non-active state");
499 h5_reset_rx(h5);
500 return 0;
501 }
502
503 h5->rx_func = h5_rx_payload;
504 h5->rx_pending = H5_HDR_LEN(hdr);
505
506 return 0;
507}
508
509static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
510{
511 struct h5 *h5 = hu->priv;
512
513 if (c == SLIP_DELIMITER)
514 return 1;
515
516 h5->rx_func = h5_rx_3wire_hdr;
517 h5->rx_pending = 4;
518
519 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
520 if (!h5->rx_skb) {
521 bt_dev_err(hu->hdev, "Can't allocate mem for new packet");
522 h5_reset_rx(h5);
523 return -ENOMEM;
524 }
525
526 h5->rx_skb->dev = (void *)hu->hdev;
527
528 return 0;
529}
530
531static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
532{
533 struct h5 *h5 = hu->priv;
534
535 if (c == SLIP_DELIMITER)
536 h5->rx_func = h5_rx_pkt_start;
537
538 return 1;
539}
540
541static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
542{
543 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
544 const u8 *byte = &c;
545
546 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
547 set_bit(nr: H5_RX_ESC, addr: &h5->flags);
548 return;
549 }
550
551 if (test_and_clear_bit(nr: H5_RX_ESC, addr: &h5->flags)) {
552 switch (c) {
553 case SLIP_ESC_DELIM:
554 byte = &delim;
555 break;
556 case SLIP_ESC_ESC:
557 byte = &esc;
558 break;
559 default:
560 BT_ERR("Invalid esc byte 0x%02hhx", c);
561 h5_reset_rx(h5);
562 return;
563 }
564 }
565
566 skb_put_data(skb: h5->rx_skb, data: byte, len: 1);
567 h5->rx_pending--;
568
569 BT_DBG("unslipped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
570}
571
572static void h5_reset_rx(struct h5 *h5)
573{
574 if (h5->rx_skb) {
575 kfree_skb(skb: h5->rx_skb);
576 h5->rx_skb = NULL;
577 }
578
579 h5->rx_func = h5_rx_delimiter;
580 h5->rx_pending = 0;
581 clear_bit(nr: H5_RX_ESC, addr: &h5->flags);
582 clear_bit(nr: H5_CRC, addr: &h5->flags);
583}
584
585static int h5_recv(struct hci_uart *hu, const void *data, int count)
586{
587 struct h5 *h5 = hu->priv;
588 const unsigned char *ptr = data;
589
590 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
591 count);
592
593 while (count > 0) {
594 int processed;
595
596 if (h5->rx_pending > 0) {
597 if (*ptr == SLIP_DELIMITER) {
598 bt_dev_err(hu->hdev, "Too short H5 packet");
599 h5_reset_rx(h5);
600 continue;
601 }
602
603 h5_unslip_one_byte(h5, c: *ptr);
604
605 ptr++; count--;
606 continue;
607 }
608
609 processed = h5->rx_func(hu, *ptr);
610 if (processed < 0)
611 return processed;
612
613 ptr += processed;
614 count -= processed;
615 }
616
617 if (hu->serdev) {
618 pm_runtime_get(dev: &hu->serdev->dev);
619 pm_runtime_put_autosuspend(dev: &hu->serdev->dev);
620 }
621
622 return 0;
623}
624
625static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
626{
627 struct h5 *h5 = hu->priv;
628
629 if (skb->len > 0xfff) {
630 bt_dev_err(hu->hdev, "Packet too long (%u bytes)", skb->len);
631 kfree_skb(skb);
632 return 0;
633 }
634
635 if (h5->state != H5_ACTIVE) {
636 bt_dev_err(hu->hdev, "Ignoring HCI data in non-active state");
637 kfree_skb(skb);
638 return 0;
639 }
640
641 switch (hci_skb_pkt_type(skb)) {
642 case HCI_ACLDATA_PKT:
643 case HCI_COMMAND_PKT:
644 skb_queue_tail(list: &h5->rel, newsk: skb);
645 break;
646
647 case HCI_SCODATA_PKT:
648 case HCI_ISODATA_PKT:
649 skb_queue_tail(list: &h5->unrel, newsk: skb);
650 break;
651
652 default:
653 bt_dev_err(hu->hdev, "Unknown packet type %u", hci_skb_pkt_type(skb));
654 kfree_skb(skb);
655 break;
656 }
657
658 if (hu->serdev) {
659 pm_runtime_get_sync(dev: &hu->serdev->dev);
660 pm_runtime_put_autosuspend(dev: &hu->serdev->dev);
661 }
662
663 return 0;
664}
665
666static void h5_slip_delim(struct sk_buff *skb)
667{
668 const char delim = SLIP_DELIMITER;
669
670 skb_put_data(skb, data: &delim, len: 1);
671}
672
673static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
674{
675 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
676 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
677
678 switch (c) {
679 case SLIP_DELIMITER:
680 skb_put_data(skb, data: &esc_delim, len: 2);
681 break;
682 case SLIP_ESC:
683 skb_put_data(skb, data: &esc_esc, len: 2);
684 break;
685 default:
686 skb_put_data(skb, data: &c, len: 1);
687 }
688}
689
690static bool valid_packet_type(u8 type)
691{
692 switch (type) {
693 case HCI_ACLDATA_PKT:
694 case HCI_COMMAND_PKT:
695 case HCI_SCODATA_PKT:
696 case HCI_ISODATA_PKT:
697 case HCI_3WIRE_LINK_PKT:
698 case HCI_3WIRE_ACK_PKT:
699 return true;
700 default:
701 return false;
702 }
703}
704
705static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
706 const u8 *data, size_t len)
707{
708 struct h5 *h5 = hu->priv;
709 struct sk_buff *nskb;
710 u8 hdr[4];
711 u16 crc;
712 int i;
713
714 if (!valid_packet_type(type: pkt_type)) {
715 bt_dev_err(hu->hdev, "Unknown packet type %u", pkt_type);
716 return NULL;
717 }
718
719 /*
720 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
721 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
722 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
723 * delimiters at start and end).
724 */
725 nskb = alloc_skb(size: (len + 6) * 2 + 2, GFP_ATOMIC);
726 if (!nskb)
727 return NULL;
728
729 hci_skb_pkt_type(nskb) = pkt_type;
730
731 h5_slip_delim(skb: nskb);
732
733 hdr[0] = h5->tx_ack << 3;
734 clear_bit(nr: H5_TX_ACK_REQ, addr: &h5->flags);
735
736 /* Reliable packet? */
737 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
738 hdr[0] |= 1 << 7;
739 hdr[0] |= (test_bit(H5_CRC, &h5->flags) && 1) << 6;
740 hdr[0] |= h5->tx_seq;
741 h5->tx_seq = (h5->tx_seq + 1) % 8;
742 }
743
744 hdr[1] = pkt_type | ((len & 0x0f) << 4);
745 hdr[2] = len >> 4;
746 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
747
748 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
749 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
750 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
751 H5_HDR_LEN(hdr));
752
753 for (i = 0; i < 4; i++)
754 h5_slip_one_byte(skb: nskb, c: hdr[i]);
755
756 for (i = 0; i < len; i++)
757 h5_slip_one_byte(skb: nskb, c: data[i]);
758
759 if (H5_HDR_CRC(hdr)) {
760 crc = crc_ccitt(crc: 0xffff, buffer: hdr, len: 4);
761 crc = crc_ccitt(crc, buffer: data, len);
762 crc = bitrev16(crc);
763
764 h5_slip_one_byte(skb: nskb, c: (crc >> 8) & 0xff);
765 h5_slip_one_byte(skb: nskb, c: crc & 0xff);
766 }
767
768 h5_slip_delim(skb: nskb);
769
770 return nskb;
771}
772
773static struct sk_buff *h5_dequeue(struct hci_uart *hu)
774{
775 struct h5 *h5 = hu->priv;
776 unsigned long flags;
777 struct sk_buff *skb, *nskb;
778
779 if (h5->sleep != H5_AWAKE) {
780 const unsigned char wakeup_req[] = { 0x05, 0xfa };
781
782 if (h5->sleep == H5_WAKING_UP)
783 return NULL;
784
785 h5->sleep = H5_WAKING_UP;
786 BT_DBG("Sending wakeup request");
787
788 mod_timer(timer: &h5->timer, expires: jiffies + HZ / 100);
789 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, data: wakeup_req, len: 2);
790 }
791
792 skb = skb_dequeue(list: &h5->unrel);
793 if (skb) {
794 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
795 data: skb->data, len: skb->len);
796 if (nskb) {
797 kfree_skb(skb);
798 return nskb;
799 }
800
801 skb_queue_head(list: &h5->unrel, newsk: skb);
802 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
803 }
804
805 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
806
807 if (h5->unack.qlen >= h5->tx_win)
808 goto unlock;
809
810 skb = skb_dequeue(list: &h5->rel);
811 if (skb) {
812 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
813 data: skb->data, len: skb->len);
814 if (nskb) {
815 __skb_queue_tail(list: &h5->unack, newsk: skb);
816 mod_timer(timer: &h5->timer, expires: jiffies + H5_ACK_TIMEOUT);
817 spin_unlock_irqrestore(lock: &h5->unack.lock, flags);
818 return nskb;
819 }
820
821 skb_queue_head(list: &h5->rel, newsk: skb);
822 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
823 }
824
825unlock:
826 spin_unlock_irqrestore(lock: &h5->unack.lock, flags);
827
828 if (test_bit(H5_TX_ACK_REQ, &h5->flags))
829 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, len: 0);
830
831 return NULL;
832}
833
834static int h5_flush(struct hci_uart *hu)
835{
836 BT_DBG("hu %p", hu);
837 return 0;
838}
839
840static const struct hci_uart_proto h5p = {
841 .id = HCI_UART_3WIRE,
842 .name = "Three-wire (H5)",
843 .open = h5_open,
844 .close = h5_close,
845 .setup = h5_setup,
846 .recv = h5_recv,
847 .enqueue = h5_enqueue,
848 .dequeue = h5_dequeue,
849 .flush = h5_flush,
850};
851
852static int h5_serdev_probe(struct serdev_device *serdev)
853{
854 struct device *dev = &serdev->dev;
855 struct h5 *h5;
856 const struct h5_device_data *data;
857
858 h5 = devm_kzalloc(dev, size: sizeof(*h5), GFP_KERNEL);
859 if (!h5)
860 return -ENOMEM;
861
862 h5->hu = &h5->serdev_hu;
863 h5->serdev_hu.serdev = serdev;
864 serdev_device_set_drvdata(serdev, data: h5);
865
866 if (has_acpi_companion(dev)) {
867 const struct acpi_device_id *match;
868
869 match = acpi_match_device(ids: dev->driver->acpi_match_table, dev);
870 if (!match)
871 return -ENODEV;
872
873 data = (const struct h5_device_data *)match->driver_data;
874 h5->vnd = data->vnd;
875 h5->id = (char *)match->id;
876
877 if (h5->vnd->acpi_gpio_map)
878 devm_acpi_dev_add_driver_gpios(dev,
879 gpios: h5->vnd->acpi_gpio_map);
880 } else {
881 data = of_device_get_match_data(dev);
882 if (!data)
883 return -ENODEV;
884
885 h5->vnd = data->vnd;
886 }
887
888 if (data->driver_info & H5_INFO_WAKEUP_DISABLE)
889 set_bit(nr: H5_WAKEUP_DISABLE, addr: &h5->flags);
890
891 h5->enable_gpio = devm_gpiod_get_optional(dev, con_id: "enable", flags: GPIOD_OUT_LOW);
892 if (IS_ERR(ptr: h5->enable_gpio))
893 return PTR_ERR(ptr: h5->enable_gpio);
894
895 h5->device_wake_gpio = devm_gpiod_get_optional(dev, con_id: "device-wake",
896 flags: GPIOD_OUT_LOW);
897 if (IS_ERR(ptr: h5->device_wake_gpio))
898 return PTR_ERR(ptr: h5->device_wake_gpio);
899
900 return hci_uart_register_device_priv(hu: &h5->serdev_hu, p: &h5p,
901 sizeof_priv: h5->vnd->sizeof_priv);
902}
903
904static void h5_serdev_remove(struct serdev_device *serdev)
905{
906 struct h5 *h5 = serdev_device_get_drvdata(serdev);
907
908 hci_uart_unregister_device(hu: &h5->serdev_hu);
909}
910
911static int __maybe_unused h5_serdev_suspend(struct device *dev)
912{
913 struct h5 *h5 = dev_get_drvdata(dev);
914 int ret = 0;
915
916 if (h5->vnd && h5->vnd->suspend)
917 ret = h5->vnd->suspend(h5);
918
919 return ret;
920}
921
922static int __maybe_unused h5_serdev_resume(struct device *dev)
923{
924 struct h5 *h5 = dev_get_drvdata(dev);
925 int ret = 0;
926
927 if (h5->vnd && h5->vnd->resume)
928 ret = h5->vnd->resume(h5);
929
930 return ret;
931}
932
933#ifdef CONFIG_BT_HCIUART_RTL
934static int h5_btrtl_setup(struct h5 *h5)
935{
936 struct btrtl_device_info *btrtl_dev;
937 struct sk_buff *skb;
938 __le32 baudrate_data;
939 u32 device_baudrate;
940 unsigned int controller_baudrate;
941 bool flow_control;
942 int err;
943
944 btrtl_dev = btrtl_initialize(hdev: h5->hu->hdev, postfix: h5->id);
945 if (IS_ERR(ptr: btrtl_dev))
946 return PTR_ERR(ptr: btrtl_dev);
947
948 err = btrtl_get_uart_settings(hdev: h5->hu->hdev, btrtl_dev,
949 controller_baudrate: &controller_baudrate, device_baudrate: &device_baudrate,
950 flow_control: &flow_control);
951 if (err)
952 goto out_free;
953
954 baudrate_data = cpu_to_le32(device_baudrate);
955 skb = __hci_cmd_sync(hdev: h5->hu->hdev, opcode: 0xfc17, plen: sizeof(baudrate_data),
956 param: &baudrate_data, HCI_INIT_TIMEOUT);
957 if (IS_ERR(ptr: skb)) {
958 rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n");
959 err = PTR_ERR(ptr: skb);
960 goto out_free;
961 } else {
962 kfree_skb(skb);
963 }
964 /* Give the device some time to set up the new baudrate. */
965 usleep_range(min: 10000, max: 20000);
966
967 serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate);
968 serdev_device_set_flow_control(h5->hu->serdev, flow_control);
969
970 if (flow_control)
971 set_bit(nr: H5_HW_FLOW_CONTROL, addr: &h5->flags);
972
973 err = btrtl_download_firmware(hdev: h5->hu->hdev, btrtl_dev);
974 /* Give the device some time before the hci-core sends it a reset */
975 usleep_range(min: 10000, max: 20000);
976 if (err)
977 goto out_free;
978
979 btrtl_set_quirks(hdev: h5->hu->hdev, btrtl_dev);
980
981out_free:
982 btrtl_free(btrtl_dev);
983
984 return err;
985}
986
987static void h5_btrtl_open(struct h5 *h5)
988{
989 /*
990 * Since h5_btrtl_resume() does a device_reprobe() the suspend handling
991 * done by the hci_suspend_notifier is not necessary; it actually causes
992 * delays and a bunch of errors to get logged, so disable it.
993 */
994 if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
995 set_bit(HCI_UART_NO_SUSPEND_NOTIFIER, addr: &h5->hu->flags);
996
997 /* Devices always start with these fixed parameters */
998 serdev_device_set_flow_control(h5->hu->serdev, false);
999 serdev_device_set_parity(serdev: h5->hu->serdev, parity: SERDEV_PARITY_EVEN);
1000 serdev_device_set_baudrate(h5->hu->serdev, 115200);
1001
1002 if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
1003 pm_runtime_set_active(dev: &h5->hu->serdev->dev);
1004 pm_runtime_use_autosuspend(dev: &h5->hu->serdev->dev);
1005 pm_runtime_set_autosuspend_delay(dev: &h5->hu->serdev->dev,
1006 SUSPEND_TIMEOUT_MS);
1007 pm_runtime_enable(dev: &h5->hu->serdev->dev);
1008 }
1009
1010 /* The controller needs reset to startup */
1011 gpiod_set_value_cansleep(desc: h5->enable_gpio, value: 0);
1012 gpiod_set_value_cansleep(desc: h5->device_wake_gpio, value: 0);
1013 msleep(msecs: 100);
1014
1015 /* The controller needs up to 500ms to wakeup */
1016 gpiod_set_value_cansleep(desc: h5->enable_gpio, value: 1);
1017 gpiod_set_value_cansleep(desc: h5->device_wake_gpio, value: 1);
1018 msleep(msecs: 500);
1019}
1020
1021static void h5_btrtl_close(struct h5 *h5)
1022{
1023 if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags))
1024 pm_runtime_disable(dev: &h5->hu->serdev->dev);
1025
1026 gpiod_set_value_cansleep(desc: h5->device_wake_gpio, value: 0);
1027 gpiod_set_value_cansleep(desc: h5->enable_gpio, value: 0);
1028}
1029
1030/* Suspend/resume support. On many devices the RTL BT device loses power during
1031 * suspend/resume, causing it to lose its firmware and all state. So we simply
1032 * turn it off on suspend and reprobe on resume. This mirrors how RTL devices
1033 * are handled in the USB driver, where the BTUSB_WAKEUP_DISABLE is used which
1034 * also causes a reprobe on resume.
1035 */
1036static int h5_btrtl_suspend(struct h5 *h5)
1037{
1038 serdev_device_set_flow_control(h5->hu->serdev, false);
1039 gpiod_set_value_cansleep(desc: h5->device_wake_gpio, value: 0);
1040
1041 if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
1042 gpiod_set_value_cansleep(desc: h5->enable_gpio, value: 0);
1043
1044 return 0;
1045}
1046
1047struct h5_btrtl_reprobe {
1048 struct device *dev;
1049 struct work_struct work;
1050};
1051
1052static void h5_btrtl_reprobe_worker(struct work_struct *work)
1053{
1054 struct h5_btrtl_reprobe *reprobe =
1055 container_of(work, struct h5_btrtl_reprobe, work);
1056 int ret;
1057
1058 ret = device_reprobe(dev: reprobe->dev);
1059 if (ret && ret != -EPROBE_DEFER)
1060 dev_err(reprobe->dev, "Reprobe error %d\n", ret);
1061
1062 put_device(dev: reprobe->dev);
1063 kfree(objp: reprobe);
1064 module_put(THIS_MODULE);
1065}
1066
1067static int h5_btrtl_resume(struct h5 *h5)
1068{
1069 if (test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
1070 struct h5_btrtl_reprobe *reprobe;
1071
1072 reprobe = kzalloc(sizeof(*reprobe), GFP_KERNEL);
1073 if (!reprobe)
1074 return -ENOMEM;
1075
1076 __module_get(THIS_MODULE);
1077
1078 INIT_WORK(&reprobe->work, h5_btrtl_reprobe_worker);
1079 reprobe->dev = get_device(dev: &h5->hu->serdev->dev);
1080 queue_work(wq: system_long_wq, work: &reprobe->work);
1081 } else {
1082 gpiod_set_value_cansleep(desc: h5->device_wake_gpio, value: 1);
1083
1084 if (test_bit(H5_HW_FLOW_CONTROL, &h5->flags))
1085 serdev_device_set_flow_control(h5->hu->serdev, true);
1086 }
1087
1088 return 0;
1089}
1090
1091static const struct acpi_gpio_params btrtl_device_wake_gpios = { 0, 0, false };
1092static const struct acpi_gpio_params btrtl_enable_gpios = { 1, 0, false };
1093static const struct acpi_gpio_params btrtl_host_wake_gpios = { 2, 0, false };
1094static const struct acpi_gpio_mapping acpi_btrtl_gpios[] = {
1095 { "device-wake-gpios", &btrtl_device_wake_gpios, 1 },
1096 { "enable-gpios", &btrtl_enable_gpios, 1 },
1097 { "host-wake-gpios", &btrtl_host_wake_gpios, 1 },
1098 {},
1099};
1100
1101static struct h5_vnd rtl_vnd = {
1102 .setup = h5_btrtl_setup,
1103 .open = h5_btrtl_open,
1104 .close = h5_btrtl_close,
1105 .suspend = h5_btrtl_suspend,
1106 .resume = h5_btrtl_resume,
1107 .acpi_gpio_map = acpi_btrtl_gpios,
1108 .sizeof_priv = sizeof(struct btrealtek_data),
1109};
1110
1111static const struct h5_device_data h5_data_rtl8822cs = {
1112 .vnd = &rtl_vnd,
1113};
1114
1115static const struct h5_device_data h5_data_rtl8723bs = {
1116 .driver_info = H5_INFO_WAKEUP_DISABLE,
1117 .vnd = &rtl_vnd,
1118};
1119#endif
1120
1121#ifdef CONFIG_ACPI
1122static const struct acpi_device_id h5_acpi_match[] = {
1123#ifdef CONFIG_BT_HCIUART_RTL
1124 { "OBDA0623", (kernel_ulong_t)&h5_data_rtl8723bs },
1125 { "OBDA8723", (kernel_ulong_t)&h5_data_rtl8723bs },
1126#endif
1127 { },
1128};
1129MODULE_DEVICE_TABLE(acpi, h5_acpi_match);
1130#endif
1131
1132static const struct dev_pm_ops h5_serdev_pm_ops = {
1133 SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume)
1134 SET_RUNTIME_PM_OPS(h5_serdev_suspend, h5_serdev_resume, NULL)
1135};
1136
1137static const struct of_device_id rtl_bluetooth_of_match[] = {
1138#ifdef CONFIG_BT_HCIUART_RTL
1139 { .compatible = "realtek,rtl8822cs-bt",
1140 .data = (const void *)&h5_data_rtl8822cs },
1141 { .compatible = "realtek,rtl8723bs-bt",
1142 .data = (const void *)&h5_data_rtl8723bs },
1143 { .compatible = "realtek,rtl8723cs-bt",
1144 .data = (const void *)&h5_data_rtl8723bs },
1145 { .compatible = "realtek,rtl8723ds-bt",
1146 .data = (const void *)&h5_data_rtl8723bs },
1147#endif
1148 { },
1149};
1150MODULE_DEVICE_TABLE(of, rtl_bluetooth_of_match);
1151
1152static struct serdev_device_driver h5_serdev_driver = {
1153 .probe = h5_serdev_probe,
1154 .remove = h5_serdev_remove,
1155 .driver = {
1156 .name = "hci_uart_h5",
1157 .acpi_match_table = ACPI_PTR(h5_acpi_match),
1158 .pm = &h5_serdev_pm_ops,
1159 .of_match_table = rtl_bluetooth_of_match,
1160 },
1161};
1162
1163int __init h5_init(void)
1164{
1165 serdev_device_driver_register(&h5_serdev_driver);
1166 return hci_uart_register_proto(p: &h5p);
1167}
1168
1169int __exit h5_deinit(void)
1170{
1171 serdev_device_driver_unregister(sdrv: &h5_serdev_driver);
1172 return hci_uart_unregister_proto(p: &h5p);
1173}
1174

source code of linux/drivers/bluetooth/hci_h5.c