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