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