hci_h5.c

   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(3, GFP_ATOMIC);
 135	if (!nskb)
 136		return;
 137
 138	hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT;
 139
 140	skb_put_data(nskb, data, len);
 141
 142	skb_queue_tail(&h5->unrel, 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, sync_req, sizeof(sync_req));
 164
 165	if (h5->state == H5_INITIALIZED) {
 166		conf_req[2] = h5_cfg_field(h5);
 167		h5_link_control(hu, conf_req, sizeof(conf_req));
 168	}
 169
 170	if (h5->state != H5_ACTIVE) {
 171		mod_timer(&h5->timer, 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(&h5->unack)) != NULL) {
 185		h5->tx_seq = (h5->tx_seq - 1) & 0x07;
 186		skb_queue_head(&h5->rel, skb);
 187	}
 188
 189	spin_unlock_irqrestore(&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(&h5->timer);
 204
 205	skb_queue_purge(&h5->rel);
 206	skb_queue_purge(&h5->unrel);
 207	skb_queue_purge(&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(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(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(&h5->unack);
 234	skb_queue_head_init(&h5->rel);
 235	skb_queue_head_init(&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, &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(&h5->timer, 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(&h5->timer);
 262
 263	skb_queue_purge(&h5->unack);
 264	skb_queue_purge(&h5->rel);
 265	skb_queue_purge(&h5->unrel);
 266
 267	kfree_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(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(&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, &h5->unack);
 321		dev_kfree_skb_irq(skb);
 322	}
 323
 324	if (skb_queue_empty(&h5->unack))
 325		timer_delete(&h5->timer);
 326
 327unlock:
 328	spin_unlock_irqrestore(&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(data, sync_req, 2) == 0) {
 355		if (h5->state == H5_ACTIVE)
 356			h5_peer_reset(hu);
 357		h5_link_control(hu, sync_rsp, 2);
 358	} else if (memcmp(data, sync_rsp, 2) == 0) {
 359		if (h5->state == H5_ACTIVE)
 360			h5_peer_reset(hu);
 361		h5->state = H5_INITIALIZED;
 362		h5_link_control(hu, conf_req, 3);
 363	} else if (memcmp(data, conf_req, 2) == 0) {
 364		h5_link_control(hu, conf_rsp, 2);
 365		h5_link_control(hu, conf_req, 3);
 366	} else if (memcmp(data, conf_rsp, 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(data, sleep_req, 2) == 0) {
 376		BT_DBG("Peer went to sleep");
 377		h5->sleep = H5_SLEEPING;
 378		return;
 379	} else if (memcmp(data, woken_req, 2) == 0) {
 380		BT_DBG("Peer woke up");
 381		h5->sleep = H5_AWAKE;
 382	} else if (memcmp(data, wakeup_req, 2) == 0) {
 383		BT_DBG("Peer requested wakeup");
 384		h5_link_control(hu, woken_req, 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(H5_TX_ACK_REQ, &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(h5->rx_skb, 4);
 418
 419		hci_recv_frame(hu->hdev, 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(0xffff, hdr, 4 + H5_HDR_LEN(hdr));
 440	crc = bitrev16(crc);
 441
 442	crc_be = cpu_to_be16(crc);
 443
 444	if (memcmp(&crc_be, hdr + 4 + H5_HDR_LEN(hdr), 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(h5->rx_skb, 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(H5_TX_ACK_REQ, &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(H5_RX_ESC, &h5->flags);
 548		return;
 549	}
 550
 551	if (test_and_clear_bit(H5_RX_ESC, &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(h5->rx_skb, byte, 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(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(H5_RX_ESC, &h5->flags);
 582	clear_bit(H5_CRC, &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, *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(&hu->serdev->dev);
 619		pm_runtime_put_autosuspend(&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(&h5->rel, skb);
 645		break;
 646
 647	case HCI_SCODATA_PKT:
 648	case HCI_ISODATA_PKT:
 649		skb_queue_tail(&h5->unrel, 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(&hu->serdev->dev);
 660		pm_runtime_put_autosuspend(&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, &delim, 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, &esc_delim, 2);
 681		break;
 682	case SLIP_ESC:
 683		skb_put_data(skb, &esc_esc, 2);
 684		break;
 685	default:
 686		skb_put_data(skb, &c, 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(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((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(nskb);
 732
 733	hdr[0] = h5->tx_ack << 3;
 734	clear_bit(H5_TX_ACK_REQ, &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(nskb, hdr[i]);
 755
 756	for (i = 0; i < len; i++)
 757		h5_slip_one_byte(nskb, data[i]);
 758
 759	if (H5_HDR_CRC(hdr)) {
 760		crc = crc_ccitt(0xffff, hdr, 4);
 761		crc = crc_ccitt(crc, data, len);
 762		crc = bitrev16(crc);
 763
 764		h5_slip_one_byte(nskb, (crc >> 8) & 0xff);
 765		h5_slip_one_byte(nskb, crc & 0xff);
 766	}
 767
 768	h5_slip_delim(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(&h5->timer, jiffies + HZ / 100);
 789		return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
 790	}
 791
 792	skb = skb_dequeue(&h5->unrel);
 793	if (skb) {
 794		nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 795				      skb->data, skb->len);
 796		if (nskb) {
 797			kfree_skb(skb);
 798			return nskb;
 799		}
 800
 801		skb_queue_head(&h5->unrel, 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(&h5->rel);
 811	if (skb) {
 812		nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 813				      skb->data, skb->len);
 814		if (nskb) {
 815			__skb_queue_tail(&h5->unack, skb);
 816			mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
 817			spin_unlock_irqrestore(&h5->unack.lock, flags);
 818			return nskb;
 819		}
 820
 821		skb_queue_head(&h5->rel, skb);
 822		bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
 823	}
 824
 825unlock:
 826	spin_unlock_irqrestore(&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, 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, 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, h5);
 865
 866	if (has_acpi_companion(dev)) {
 867		const struct acpi_device_id *match;
 868
 869		match = acpi_match_device(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						       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(H5_WAKEUP_DISABLE, &h5->flags);
 890
 891	h5->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
 892	if (IS_ERR(h5->enable_gpio))
 893		return PTR_ERR(h5->enable_gpio);
 894
 895	h5->device_wake_gpio = devm_gpiod_get_optional(dev, "device-wake",
 896						       GPIOD_OUT_LOW);
 897	if (IS_ERR(h5->device_wake_gpio))
 898		return PTR_ERR(h5->device_wake_gpio);
 899
 900	return hci_uart_register_device_priv(&h5->serdev_hu, &h5p,
 901					     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(&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(h5->hu->hdev, h5->id);
 945	if (IS_ERR(btrtl_dev))
 946		return PTR_ERR(btrtl_dev);
 947
 948	err = btrtl_get_uart_settings(h5->hu->hdev, btrtl_dev,
 949				      &controller_baudrate, &device_baudrate,
 950				      &flow_control);
 951	if (err)
 952		goto out_free;
 953
 954	baudrate_data = cpu_to_le32(device_baudrate);
 955	skb = __hci_cmd_sync(h5->hu->hdev, 0xfc17, sizeof(baudrate_data),
 956			     &baudrate_data, HCI_INIT_TIMEOUT);
 957	if (IS_ERR(skb)) {
 958		rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n");
 959		err = PTR_ERR(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(10000, 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(H5_HW_FLOW_CONTROL, &h5->flags);
 972
 973	err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev);
 974	/* Give the device some time before the hci-core sends it a reset */
 975	usleep_range(10000, 20000);
 976	if (err)
 977		goto out_free;
 978
 979	btrtl_set_quirks(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, &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(h5->hu->serdev, 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(&h5->hu->serdev->dev);
1004		pm_runtime_use_autosuspend(&h5->hu->serdev->dev);
1005		pm_runtime_set_autosuspend_delay(&h5->hu->serdev->dev,
1006						 SUSPEND_TIMEOUT_MS);
1007		pm_runtime_enable(&h5->hu->serdev->dev);
1008	}
1009
1010	/* The controller needs reset to startup */
1011	gpiod_set_value_cansleep(h5->enable_gpio, 0);
1012	gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
1013	msleep(100);
1014
1015	/* The controller needs up to 500ms to wakeup */
1016	gpiod_set_value_cansleep(h5->enable_gpio, 1);
1017	gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
1018	msleep(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(&h5->hu->serdev->dev);
1025
1026	gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
1027	gpiod_set_value_cansleep(h5->enable_gpio, 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(h5->device_wake_gpio, 0);
1040
1041	if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
1042		gpiod_set_value_cansleep(h5->enable_gpio, 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(reprobe->dev);
1059	if (ret && ret != -EPROBE_DEFER)
1060		dev_err(reprobe->dev, "Reprobe error %d\n", ret);
1061
1062	put_device(reprobe->dev);
1063	kfree(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(&h5->hu->serdev->dev);
1080		queue_work(system_long_wq, &reprobe->work);
1081	} else {
1082		gpiod_set_value_cansleep(h5->device_wake_gpio, 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(&h5p);
1167}
1168
1169int __exit h5_deinit(void)
1170{
1171	serdev_device_driver_unregister(&h5_serdev_driver);
1172	return hci_uart_unregister_proto(&h5p);
1173}