[deliverable/linux.git] / drivers / bluetooth / hci_h5.c

/*
 *
 *  Bluetooth HCI Three-wire UART driver
 *
 *  Copyright (C) 2012  Intel Corporation
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/skbuff.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#include "hci_uart.h"

#define HCI_3WIRE_ACK_PKT	0
#define HCI_3WIRE_LINK_PKT	15

#define H5_TXWINSIZE	4

#define H5_ACK_TIMEOUT	msecs_to_jiffies(250)
#define H5_SYNC_TIMEOUT	msecs_to_jiffies(100)

/*
 * Maximum Three-wire packet:
 *     4 byte header + max value for 12-bit length + 2 bytes for CRC
 */
#define H5_MAX_LEN (4 + 0xfff + 2)

/* Convenience macros for reading Three-wire header values */
#define H5_HDR_SEQ(hdr)		((hdr)[0] & 0x07)
#define H5_HDR_ACK(hdr)		(((hdr)[0] >> 3) & 0x07)
#define H5_HDR_CRC(hdr)		(((hdr)[0] >> 6) & 0x01)
#define H5_HDR_RELIABLE(hdr)	(((hdr)[0] >> 7) & 0x01)
#define H5_HDR_PKT_TYPE(hdr)	((hdr)[1] & 0x0f)
#define H5_HDR_LEN(hdr)		((((hdr)[1] >> 4) & 0xff) + ((hdr)[2] << 4))

#define SLIP_DELIMITER	0xc0
#define SLIP_ESC	0xdb
#define SLIP_ESC_DELIM	0xdc
#define SLIP_ESC_ESC	0xdd

struct h5 {
	struct sk_buff_head	unack;		/* Unack'ed packets queue */
	struct sk_buff_head	rel;		/* Reliable packets queue */
	struct sk_buff_head	unrel;		/* Unreliable packets queue */

	struct sk_buff		*rx_skb;	/* Receive buffer */
	size_t			rx_pending;	/* Expecting more bytes */
	bool			rx_esc;		/* SLIP escape mode */
	u8			rx_ack;		/* Last ack number received */

	int			(*rx_func) (struct hci_uart *hu, u8 c);

	struct timer_list	timer;		/* Retransmission timer */

	bool			tx_ack_req;	/* Pending ack to send */
	u8			tx_seq;		/* Next seq number to send */
	u8			tx_ack;		/* Next ack number to send */

	enum {
		H5_UNINITIALIZED,
		H5_INITIALIZED,
		H5_ACTIVE,
	} state;

	bool			sleeping;
};

static void h5_reset_rx(struct h5 *h5);

static void h5_link_control(struct hci_uart *hu, const void *data, size_t len)
{
	struct h5 *h5 = hu->priv;
	struct sk_buff *nskb;

	nskb = alloc_skb(3, GFP_ATOMIC);
	if (!nskb)
		return;

	bt_cb(nskb)->pkt_type = HCI_3WIRE_LINK_PKT;

	memcpy(skb_put(nskb, len), data, len);

	skb_queue_tail(&h5->unrel, nskb);
}

static void h5_timed_event(unsigned long arg)
{
	const unsigned char sync_req[] = { 0x01, 0x7e };
	const unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
	struct hci_uart *hu = (struct hci_uart *) arg;
	struct h5 *h5 = hu->priv;
	struct sk_buff *skb;
	unsigned long flags;

	if (h5->state == H5_UNINITIALIZED)
		h5_link_control(hu, sync_req, sizeof(sync_req));

	if (h5->state == H5_INITIALIZED)
		h5_link_control(hu, conf_req, sizeof(conf_req));

	if (h5->state != H5_ACTIVE) {
		mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
		goto wakeup;
	}

	BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);

	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);

	while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
		h5->tx_seq = (h5->tx_seq - 1) & 0x07;
		skb_queue_head(&h5->rel, skb);
	}

	spin_unlock_irqrestore(&h5->unack.lock, flags);

wakeup:
	hci_uart_tx_wakeup(hu);
}

static int h5_open(struct hci_uart *hu)
{
	struct h5 *h5;
	const unsigned char sync[] = { 0x01, 0x7e };

	BT_DBG("hu %p", hu);

	h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
	if (!h5)
		return -ENOMEM;

	hu->priv = h5;

	skb_queue_head_init(&h5->unack);
	skb_queue_head_init(&h5->rel);
	skb_queue_head_init(&h5->unrel);

	h5_reset_rx(h5);

	init_timer(&h5->timer);
	h5->timer.function = h5_timed_event;
	h5->timer.data = (unsigned long) hu;

	set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);

	/* Send initial sync request */
	h5_link_control(hu, sync, sizeof(sync));
	mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);

	return 0;
}

static int h5_close(struct hci_uart *hu)
{
	struct h5 *h5 = hu->priv;

	skb_queue_purge(&h5->unack);
	skb_queue_purge(&h5->rel);
	skb_queue_purge(&h5->unrel);

	del_timer(&h5->timer);

	kfree(h5);

	return 0;
}

static void h5_pkt_cull(struct h5 *h5)
{
	struct sk_buff *skb, *tmp;
	unsigned long flags;
	int i, to_remove;
	u8 seq;

	spin_lock_irqsave(&h5->unack.lock, flags);

	to_remove = skb_queue_len(&h5->unack);
	if (to_remove == 0)
		goto unlock;

	seq = h5->tx_seq;

	while (to_remove > 0) {
		if (h5->rx_ack == seq)
			break;

		to_remove--;
		seq = (seq - 1) % 8;
	}

	if (seq != h5->rx_ack)
		BT_ERR("Controller acked invalid packet");

	i = 0;
	skb_queue_walk_safe(&h5->unack, skb, tmp) {
		if (i++ >= to_remove)
			break;

		__skb_unlink(skb, &h5->unack);
		kfree_skb(skb);
	}

	if (skb_queue_empty(&h5->unack))
		del_timer(&h5->timer);

unlock:
	spin_unlock_irqrestore(&h5->unack.lock, flags);
}

static void h5_handle_internal_rx(struct hci_uart *hu)
{
	struct h5 *h5 = hu->priv;
	const unsigned char sync_req[] = { 0x01, 0x7e };
	const unsigned char sync_rsp[] = { 0x02, 0x7d };
	const unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
	const unsigned char conf_rsp[] = { 0x04, 0x7b, 0x01 };
	const unsigned char wakeup_req[] = { 0x05, 0xfa };
	const unsigned char woken_req[] = { 0x06, 0xf9 };
	const unsigned char sleep_req[] = { 0x07, 0x78 };
	const unsigned char *hdr = h5->rx_skb->data;
	const unsigned char *data = &h5->rx_skb->data[4];

	BT_DBG("%s", hu->hdev->name);

	if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
		return;

	if (H5_HDR_LEN(hdr) < 2)
		return;

	if (memcmp(data, sync_req, 2) == 0) {
		h5_link_control(hu, sync_rsp, 2);
	} else if (memcmp(data, sync_rsp, 2) == 0) {
		h5->state = H5_INITIALIZED;
		h5_link_control(hu, conf_req, 3);
	} else if (memcmp(data, conf_req, 2) == 0) {
		h5_link_control(hu, conf_rsp, 2);
		h5_link_control(hu, conf_req, 3);
	} else if (memcmp(data, conf_rsp, 2) == 0) {
		BT_DBG("Three-wire init sequence complete");
		h5->state = H5_ACTIVE;
		hci_uart_init_ready(hu);
		return;
	} else if (memcmp(data, sleep_req, 2) == 0) {
		BT_DBG("Peer went to sleep");
		h5->sleeping = true;
		h5_link_control(hu, wakeup_req, 2);
	} else if (memcmp(data, woken_req, 2) == 0) {
		BT_DBG("Peer woke up");
		h5->sleeping = false;
		return;
	} else {
		BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
		return;
	}

	hci_uart_tx_wakeup(hu);
}

static void h5_complete_rx_pkt(struct hci_uart *hu)
{
	struct h5 *h5 = hu->priv;
	const unsigned char *hdr = h5->rx_skb->data;

	if (H5_HDR_RELIABLE(hdr)) {
		h5->tx_ack = (h5->tx_ack + 1) % 8;
		h5->tx_ack_req = true;
		hci_uart_tx_wakeup(hu);
	}

	h5->rx_ack = H5_HDR_ACK(hdr);

	h5_pkt_cull(h5);

	switch (H5_HDR_PKT_TYPE(hdr)) {
	case HCI_EVENT_PKT:
	case HCI_ACLDATA_PKT:
	case HCI_SCODATA_PKT:
		bt_cb(h5->rx_skb)->pkt_type = H5_HDR_PKT_TYPE(hdr);

		/* Remove Three-wire header */
		skb_pull(h5->rx_skb, 4);

		hci_recv_frame(h5->rx_skb);
		h5->rx_skb = NULL;

		break;

	default:
		h5_handle_internal_rx(hu);
		break;
	}

	h5_reset_rx(h5);
}

static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
{
	struct h5 *h5 = hu->priv;

	h5_complete_rx_pkt(hu);
	h5_reset_rx(h5);

	return 0;
}

static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
{
	struct h5 *h5 = hu->priv;
	const unsigned char *hdr = h5->rx_skb->data;

	if (H5_HDR_CRC(hdr)) {
		h5->rx_func = h5_rx_crc;
		h5->rx_pending = 2;
	} else {
		h5_complete_rx_pkt(hu);
		h5_reset_rx(h5);
	}

	return 0;
}

static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
{
	struct h5 *h5 = hu->priv;
	const unsigned char *hdr = h5->rx_skb->data;

	BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
	       hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
	       H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
	       H5_HDR_LEN(hdr));

	if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
		BT_ERR("Invalid header checksum");
		h5_reset_rx(h5);
		return 0;
	}

	if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
		BT_ERR("Out-of-order packet arrived (%u != %u)",
		       H5_HDR_SEQ(hdr), h5->tx_ack);
		h5_reset_rx(h5);
		return 0;
	}

	if (h5->state != H5_ACTIVE &&
	    H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
		BT_ERR("Non-link packet received in non-active state");
		h5_reset_rx(h5);
	}

	h5->rx_func = h5_rx_payload;
	h5->rx_pending = H5_HDR_LEN(hdr);

	return 0;
}

static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
{
	struct h5 *h5 = hu->priv;

	if (c == SLIP_DELIMITER)
		return 1;

	h5->rx_func = h5_rx_3wire_hdr;
	h5->rx_pending = 4;

	h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
	if (!h5->rx_skb) {
		BT_ERR("Can't allocate mem for new packet");
		h5_reset_rx(h5);
		return -ENOMEM;
	}

	h5->rx_skb->dev = (void *) hu->hdev;

	return 0;
}

static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
{
	struct h5 *h5 = hu->priv;

	if (c == SLIP_DELIMITER)
		h5->rx_func = h5_rx_pkt_start;

	return 1;
}

static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
{
	const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
	const u8 *byte = &c;

	if (!h5->rx_esc && c == SLIP_ESC) {
		h5->rx_esc = true;
		return;
	}

	if (h5->rx_esc) {
		switch (c) {
		case SLIP_ESC_DELIM:
			byte = &delim;
			break;
		case SLIP_ESC_ESC:
			byte = &esc;
			break;
		default:
			BT_ERR("Invalid esc byte 0x%02hhx", c);
			h5_reset_rx(h5);
			return;
		}

		h5->rx_esc = false;
	}

	memcpy(skb_put(h5->rx_skb, 1), byte, 1);
	h5->rx_pending--;

	BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
}

static void h5_reset_rx(struct h5 *h5)
{
	if (h5->rx_skb) {
		kfree_skb(h5->rx_skb);
		h5->rx_skb = NULL;
	}

	h5->rx_func = h5_rx_delimiter;
	h5->rx_pending = 0;
	h5->rx_esc = false;
}

static int h5_recv(struct hci_uart *hu, void *data, int count)
{
	struct h5 *h5 = hu->priv;
	unsigned char *ptr = data;

	BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
	       count);

	while (count > 0) {
		int processed;

		if (h5->rx_pending > 0) {
			if (*ptr == SLIP_DELIMITER) {
				BT_ERR("Too short H5 packet");
				h5_reset_rx(h5);
				continue;
			}

			h5_unslip_one_byte(h5, *ptr);

			ptr++; count--;
			continue;
		}

		processed = h5->rx_func(hu, *ptr);
		if (processed < 0)
			return processed;

		ptr += processed;
		count -= processed;
	}

	return 0;
}

static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
	struct h5 *h5 = hu->priv;

	if (skb->len > 0xfff) {
		BT_ERR("Packet too long (%u bytes)", skb->len);
		kfree_skb(skb);
		return 0;
	}

	if (h5->state != H5_ACTIVE) {
		BT_ERR("Ignoring HCI data in non-active state");
		kfree_skb(skb);
		return 0;
	}

	switch (bt_cb(skb)->pkt_type) {
	case HCI_ACLDATA_PKT:
	case HCI_COMMAND_PKT:
		skb_queue_tail(&h5->rel, skb);
		break;

	case HCI_SCODATA_PKT:
		skb_queue_tail(&h5->unrel, skb);
		break;

	default:
		BT_ERR("Unknown packet type %u", bt_cb(skb)->pkt_type);
		kfree_skb(skb);
		break;
	}

	return 0;
}

static void h5_slip_delim(struct sk_buff *skb)
{
	const char delim = SLIP_DELIMITER;

	memcpy(skb_put(skb, 1), &delim, 1);
}

static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
{
	const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
	const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };

	switch (c) {
	case SLIP_DELIMITER:
		memcpy(skb_put(skb, 2), &esc_delim, 2);
		break;
	case SLIP_ESC:
		memcpy(skb_put(skb, 2), &esc_esc, 2);
		break;
	default:
		memcpy(skb_put(skb, 1), &c, 1);
	}
}

static struct sk_buff *h5_build_pkt(struct hci_uart *hu, bool rel, u8 pkt_type,
				    const u8 *data, size_t len)
{
	struct h5 *h5 = hu->priv;
	struct sk_buff *nskb;
	u8 hdr[4];
	int i;

	/*
	 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
	 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
	 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
	 * delimiters at start and end).
	 */
	nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
	if (!nskb)
		return NULL;

	bt_cb(nskb)->pkt_type = pkt_type;

	h5_slip_delim(nskb);

	hdr[0] = h5->tx_ack << 3;
	h5->tx_ack_req = false;

	if (rel) {
		hdr[0] |= 1 << 7;
		hdr[0] |= h5->tx_seq;
		h5->tx_seq = (h5->tx_seq + 1) % 8;
	}

	hdr[1] = pkt_type | ((len & 0x0f) << 4);
	hdr[2] = len >> 4;
	hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);

	BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
	       hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
	       H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
	       H5_HDR_LEN(hdr));

	for (i = 0; i < 4; i++)
		h5_slip_one_byte(nskb, hdr[i]);

	for (i = 0; i < len; i++)
		h5_slip_one_byte(nskb, data[i]);

	h5_slip_delim(nskb);

	return nskb;
}

static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
				      const u8 *data, size_t len)
{
	bool rel;

	switch (pkt_type) {
	case HCI_ACLDATA_PKT:
	case HCI_COMMAND_PKT:
		rel = true;
		break;
	case HCI_SCODATA_PKT:
	case HCI_3WIRE_LINK_PKT:
	case HCI_3WIRE_ACK_PKT:
		rel = false;
		break;
	default:
		BT_ERR("Unknown packet type %u", pkt_type);
		return NULL;
	}

	return h5_build_pkt(hu, rel, pkt_type, data, len);
}

static struct sk_buff *h5_dequeue(struct hci_uart *hu)
{
	struct h5 *h5 = hu->priv;
	unsigned long flags;
	struct sk_buff *skb, *nskb;

	if ((skb = skb_dequeue(&h5->unrel)) != NULL) {
		nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
				      skb->data, skb->len);
		if (nskb) {
			kfree_skb(skb);
			return nskb;
		}

		skb_queue_head(&h5->unrel, skb);
		BT_ERR("Could not dequeue pkt because alloc_skb failed");
	}

	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);

	if (h5->unack.qlen >= H5_TXWINSIZE)
		goto unlock;

	if ((skb = skb_dequeue(&h5->rel)) != NULL) {
		nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
				      skb->data, skb->len);
		if (nskb) {
			__skb_queue_tail(&h5->unack, skb);
			mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
			spin_unlock_irqrestore(&h5->unack.lock, flags);
			return nskb;
		}

		skb_queue_head(&h5->rel, skb);
		BT_ERR("Could not dequeue pkt because alloc_skb failed");
	}

unlock:
	spin_unlock_irqrestore(&h5->unack.lock, flags);

	if (h5->tx_ack_req)
		return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);

	return NULL;
}

static int h5_flush(struct hci_uart *hu)
{
	BT_DBG("hu %p", hu);
	return 0;
}

static struct hci_uart_proto h5p = {
	.id		= HCI_UART_3WIRE,
	.open		= h5_open,
	.close		= h5_close,
	.recv		= h5_recv,
	.enqueue	= h5_enqueue,
	.dequeue	= h5_dequeue,
	.flush		= h5_flush,
};

int __init h5_init(void)
{
	int err = hci_uart_register_proto(&h5p);

	if (!err)
		BT_INFO("HCI Three-wire UART (H5) protocol initialized");
	else
		BT_ERR("HCI Three-wire UART (H5) protocol init failed");

	return err;
}

int __exit h5_deinit(void)
{
	return hci_uart_unregister_proto(&h5p);
}
Commit	Line	Data
7dec65c8 JH	1	/*
	2	*
	3	* Bluetooth HCI Three-wire UART driver
	4	*
	5	* Copyright (C) 2012 Intel Corporation
	6	*
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*
	22	*/
	23
	24	#include <linux/kernel.h>
	25	#include <linux/errno.h>
	26	#include <linux/skbuff.h>
	27
	28	#include <net/bluetooth/bluetooth.h>
	29	#include <net/bluetooth/hci_core.h>
	30
	31	#include "hci_uart.h"
	32
c0a1b73c JH	33	#define HCI_3WIRE_ACK_PKT 0
	34	#define HCI_3WIRE_LINK_PKT 15
	35
3f27e95b JH	36	#define H5_TXWINSIZE 4
	37
	38	#define H5_ACK_TIMEOUT msecs_to_jiffies(250)
40f10224	39	#define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
3f27e95b	40
bc1f35b9 JH	41	/*
	42	* Maximum Three-wire packet:
	43	* 4 byte header + max value for 12-bit length + 2 bytes for CRC
	44	*/
	45	#define H5_MAX_LEN (4 + 0xfff + 2)
	46
01977c0b JH	47	/* Convenience macros for reading Three-wire header values */
	48	#define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07)
	49	#define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07)
	50	#define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01)
	51	#define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01)
	52	#define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f)
	53	#define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0xff) + ((hdr)[2] << 4))
	54
bc1f35b9 JH	55	#define SLIP_DELIMITER 0xc0
	56	#define SLIP_ESC 0xdb
	57	#define SLIP_ESC_DELIM 0xdc
	58	#define SLIP_ESC_ESC 0xdd
	59
7d664fba	60	struct h5 {
bc1f35b9 JH	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	struct sk_buff rx_skb; / Receive buffer */
	66	size_t rx_pending; /* Expecting more bytes */
	67	bool rx_esc; /* SLIP escape mode */
43eb12d7	68	u8 rx_ack; /* Last ack number received */
7d664fba	69
bc1f35b9	70	int (rx_func) (struct hci_uart hu, u8 c);
7d664fba	71
bc1f35b9	72	struct timer_list timer; /* Retransmission timer */
3f27e95b	73
43eb12d7 JH	74	bool tx_ack_req; /* Pending ack to send */
43eb12d7 JH	75	u8 tx_seq; /* Next seq number to send */
40f10224	76	u8 tx_ack; /* Next ack number to send */
10122d07	77
f674a057 JH	78	enum {
	79	H5_UNINITIALIZED,
	80	H5_INITIALIZED,
	81	H5_ACTIVE,
	82	} state;
	83
10122d07	84	bool sleeping;
7d664fba JH	85	};
7d664fba JH	86
bc1f35b9 JH	87	static void h5_reset_rx(struct h5 *h5);
bc1f35b9 JH	88
f674a057 JH	89	static void h5_link_control(struct hci_uart hu, const void data, size_t len)
	90	{
	91	struct h5 *h5 = hu->priv;
	92	struct sk_buff *nskb;
	93
	94	nskb = alloc_skb(3, GFP_ATOMIC);
	95	if (!nskb)
	96	return;
	97
	98	bt_cb(nskb)->pkt_type = HCI_3WIRE_LINK_PKT;
	99
	100	memcpy(skb_put(nskb, len), data, len);
	101
	102	skb_queue_tail(&h5->unrel, nskb);
	103	}
	104
3f27e95b JH	105	static void h5_timed_event(unsigned long arg)
3f27e95b JH	106	{
f674a057 JH	107	const unsigned char sync_req[] = { 0x01, 0x7e };
f674a057 JH	108	const unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
3f27e95b JH	109	struct hci_uart hu = (struct hci_uart ) arg;
	110	struct h5 *h5 = hu->priv;
	111	struct sk_buff *skb;
	112	unsigned long flags;
	113
f674a057 JH	114	if (h5->state == H5_UNINITIALIZED)
	115	h5_link_control(hu, sync_req, sizeof(sync_req));
	116
	117	if (h5->state == H5_INITIALIZED)
	118	h5_link_control(hu, conf_req, sizeof(conf_req));
	119
	120	if (h5->state != H5_ACTIVE) {
	121	mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
	122	goto wakeup;
	123	}
	124
3f27e95b JH	125	BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
	126
	127	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
	128
	129	while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
43eb12d7	130	h5->tx_seq = (h5->tx_seq - 1) & 0x07;
3f27e95b JH	131	skb_queue_head(&h5->rel, skb);
	132	}
	133
	134	spin_unlock_irqrestore(&h5->unack.lock, flags);
	135
f674a057	136	wakeup:
3f27e95b JH	137	hci_uart_tx_wakeup(hu);
	138	}
	139
7dec65c8 JH	140	static int h5_open(struct hci_uart *hu)
7dec65c8 JH	141	{
7d664fba	142	struct h5 *h5;
40f10224	143	const unsigned char sync[] = { 0x01, 0x7e };
7d664fba JH	144
	145	BT_DBG("hu %p", hu);
	146
	147	h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
	148	if (!h5)
	149	return -ENOMEM;
	150
	151	hu->priv = h5;
	152
	153	skb_queue_head_init(&h5->unack);
	154	skb_queue_head_init(&h5->rel);
	155	skb_queue_head_init(&h5->unrel);
	156
bc1f35b9 JH	157	h5_reset_rx(h5);
bc1f35b9 JH	158
3f27e95b JH	159	init_timer(&h5->timer);
	160	h5->timer.function = h5_timed_event;
	161	h5->timer.data = (unsigned long) hu;
	162
cd1b4425 JH	163	set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
cd1b4425 JH	164
40f10224 JH	165	/* Send initial sync request */
	166	h5_link_control(hu, sync, sizeof(sync));
	167	mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
	168
7d664fba	169	return 0;
7dec65c8 JH	170	}
	171
	172	static int h5_close(struct hci_uart *hu)
	173	{
7d664fba JH	174	struct h5 *h5 = hu->priv;
	175
	176	skb_queue_purge(&h5->unack);
	177	skb_queue_purge(&h5->rel);
	178	skb_queue_purge(&h5->unrel);
	179
3f27e95b JH	180	del_timer(&h5->timer);
3f27e95b JH	181
7d664fba JH	182	kfree(h5);
	183
	184	return 0;
7dec65c8 JH	185	}
7dec65c8 JH	186
43eb12d7 JH	187	static void h5_pkt_cull(struct h5 *h5)
	188	{
	189	struct sk_buff skb, tmp;
	190	unsigned long flags;
	191	int i, to_remove;
	192	u8 seq;
	193
	194	spin_lock_irqsave(&h5->unack.lock, flags);
	195
	196	to_remove = skb_queue_len(&h5->unack);
40f10224 JH	197	if (to_remove == 0)
40f10224 JH	198	goto unlock;
43eb12d7 JH	199
	200	seq = h5->tx_seq;
	201
	202	while (to_remove > 0) {
	203	if (h5->rx_ack == seq)
	204	break;
	205
	206	to_remove--;
	207	seq = (seq - 1) % 8;
	208	}
	209
	210	if (seq != h5->rx_ack)
	211	BT_ERR("Controller acked invalid packet");
	212
	213	i = 0;
	214	skb_queue_walk_safe(&h5->unack, skb, tmp) {
	215	if (i++ >= to_remove)
	216	break;
	217
	218	__skb_unlink(skb, &h5->unack);
	219	kfree_skb(skb);
	220	}
	221
	222	if (skb_queue_empty(&h5->unack))
	223	del_timer(&h5->timer);
	224
40f10224	225	unlock:
43eb12d7 JH	226	spin_unlock_irqrestore(&h5->unack.lock, flags);
	227	}
	228
bc1f35b9 JH	229	static void h5_handle_internal_rx(struct hci_uart *hu)
bc1f35b9 JH	230	{
40f10224 JH	231	struct h5 *h5 = hu->priv;
	232	const unsigned char sync_req[] = { 0x01, 0x7e };
	233	const unsigned char sync_rsp[] = { 0x02, 0x7d };
	234	const unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
	235	const unsigned char conf_rsp[] = { 0x04, 0x7b, 0x01 };
10122d07 JH	236	const unsigned char wakeup_req[] = { 0x05, 0xfa };
	237	const unsigned char woken_req[] = { 0x06, 0xf9 };
	238	const unsigned char sleep_req[] = { 0x07, 0x78 };
40f10224 JH	239	const unsigned char *hdr = h5->rx_skb->data;
	240	const unsigned char *data = &h5->rx_skb->data[4];
	241
bc1f35b9	242	BT_DBG("%s", hu->hdev->name);
40f10224 JH	243
	244	if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
	245	return;
	246
	247	if (H5_HDR_LEN(hdr) < 2)
	248	return;
	249
	250	if (memcmp(data, sync_req, 2) == 0) {
	251	h5_link_control(hu, sync_rsp, 2);
	252	} else if (memcmp(data, sync_rsp, 2) == 0) {
f674a057	253	h5->state = H5_INITIALIZED;
40f10224 JH	254	h5_link_control(hu, conf_req, 3);
	255	} else if (memcmp(data, conf_req, 2) == 0) {
	256	h5_link_control(hu, conf_rsp, 2);
	257	h5_link_control(hu, conf_req, 3);
	258	} else if (memcmp(data, conf_rsp, 2) == 0) {
	259	BT_DBG("Three-wire init sequence complete");
f674a057	260	h5->state = H5_ACTIVE;
cd1b4425	261	hci_uart_init_ready(hu);
40f10224	262	return;
10122d07 JH	263	} else if (memcmp(data, sleep_req, 2) == 0) {
	264	BT_DBG("Peer went to sleep");
	265	h5->sleeping = true;
	266	h5_link_control(hu, wakeup_req, 2);
	267	} else if (memcmp(data, woken_req, 2) == 0) {
	268	BT_DBG("Peer woke up");
	269	h5->sleeping = false;
	270	return;
40f10224 JH	271	} else {
	272	BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
	273	return;
	274	}
	275
	276	hci_uart_tx_wakeup(hu);
bc1f35b9 JH	277	}
	278
	279	static void h5_complete_rx_pkt(struct hci_uart *hu)
	280	{
	281	struct h5 *h5 = hu->priv;
43eb12d7	282	const unsigned char *hdr = h5->rx_skb->data;
bc1f35b9	283
43eb12d7	284	if (H5_HDR_RELIABLE(hdr)) {
40f10224	285	h5->tx_ack = (h5->tx_ack + 1) % 8;
43eb12d7	286	h5->tx_ack_req = true;
40f10224	287	hci_uart_tx_wakeup(hu);
43eb12d7	288	}
bc1f35b9	289
43eb12d7 JH	290	h5->rx_ack = H5_HDR_ACK(hdr);
	291
	292	h5_pkt_cull(h5);
	293
	294	switch (H5_HDR_PKT_TYPE(hdr)) {
bc1f35b9 JH	295	case HCI_EVENT_PKT:
	296	case HCI_ACLDATA_PKT:
	297	case HCI_SCODATA_PKT:
43eb12d7	298	bt_cb(h5->rx_skb)->pkt_type = H5_HDR_PKT_TYPE(hdr);
bc1f35b9 JH	299
	300	/* Remove Three-wire header */
	301	skb_pull(h5->rx_skb, 4);
	302
	303	hci_recv_frame(h5->rx_skb);
	304	h5->rx_skb = NULL;
	305
	306	break;
	307
	308	default:
	309	h5_handle_internal_rx(hu);
	310	break;
	311	}
	312
	313	h5_reset_rx(h5);
	314	}
	315
	316	static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
	317	{
	318	struct h5 *h5 = hu->priv;
	319
bc1f35b9 JH	320	h5_complete_rx_pkt(hu);
	321	h5_reset_rx(h5);
	322
	323	return 0;
	324	}
	325
	326	static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
	327	{
	328	struct h5 *h5 = hu->priv;
	329	const unsigned char *hdr = h5->rx_skb->data;
	330
43eb12d7	331	if (H5_HDR_CRC(hdr)) {
bc1f35b9 JH	332	h5->rx_func = h5_rx_crc;
	333	h5->rx_pending = 2;
	334	} else {
	335	h5_complete_rx_pkt(hu);
	336	h5_reset_rx(h5);
	337	}
	338
	339	return 0;
	340	}
	341
	342	static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
	343	{
	344	struct h5 *h5 = hu->priv;
	345	const unsigned char *hdr = h5->rx_skb->data;
	346
40f10224 JH	347	BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
	348	hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
	349	H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
	350	H5_HDR_LEN(hdr));
	351
bc1f35b9 JH	352	if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
	353	BT_ERR("Invalid header checksum");
	354	h5_reset_rx(h5);
	355	return 0;
	356	}
	357
40f10224	358	if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
43eb12d7	359	BT_ERR("Out-of-order packet arrived (%u != %u)",
40f10224	360	H5_HDR_SEQ(hdr), h5->tx_ack);
43eb12d7 JH	361	h5_reset_rx(h5);
	362	return 0;
	363	}
	364
f674a057 JH	365	if (h5->state != H5_ACTIVE &&
	366	H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
	367	BT_ERR("Non-link packet received in non-active state");
	368	h5_reset_rx(h5);
	369	}
	370
bc1f35b9	371	h5->rx_func = h5_rx_payload;
43eb12d7	372	h5->rx_pending = H5_HDR_LEN(hdr);
bc1f35b9 JH	373
	374	return 0;
	375	}
	376
	377	static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
	378	{
	379	struct h5 *h5 = hu->priv;
	380
bc1f35b9 JH	381	if (c == SLIP_DELIMITER)
	382	return 1;
	383
	384	h5->rx_func = h5_rx_3wire_hdr;
	385	h5->rx_pending = 4;
	386
	387	h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
	388	if (!h5->rx_skb) {
	389	BT_ERR("Can't allocate mem for new packet");
	390	h5_reset_rx(h5);
	391	return -ENOMEM;
	392	}
	393
	394	h5->rx_skb->dev = (void *) hu->hdev;
	395
	396	return 0;
	397	}
	398
	399	static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
	400	{
	401	struct h5 *h5 = hu->priv;
	402
bc1f35b9 JH	403	if (c == SLIP_DELIMITER)
	404	h5->rx_func = h5_rx_pkt_start;
	405
	406	return 1;
	407	}
	408
	409	static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
	410	{
	411	const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
	412	const u8 *byte = &c;
	413
	414	if (!h5->rx_esc && c == SLIP_ESC) {
	415	h5->rx_esc = true;
	416	return;
	417	}
	418
	419	if (h5->rx_esc) {
	420	switch (c) {
	421	case SLIP_ESC_DELIM:
	422	byte = &delim;
	423	break;
	424	case SLIP_ESC_ESC:
	425	byte = &esc;
	426	break;
	427	default:
	428	BT_ERR("Invalid esc byte 0x%02hhx", c);
	429	h5_reset_rx(h5);
	430	return;
	431	}
	432
	433	h5->rx_esc = false;
	434	}
	435
	436	memcpy(skb_put(h5->rx_skb, 1), byte, 1);
	437	h5->rx_pending--;
	438
255a68e0	439	BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
bc1f35b9 JH	440	}
	441
	442	static void h5_reset_rx(struct h5 *h5)
	443	{
	444	if (h5->rx_skb) {
	445	kfree_skb(h5->rx_skb);
	446	h5->rx_skb = NULL;
	447	}
	448
	449	h5->rx_func = h5_rx_delimiter;
	450	h5->rx_pending = 0;
	451	h5->rx_esc = false;
	452	}
	453
7dec65c8 JH	454	static int h5_recv(struct hci_uart hu, void data, int count)
7dec65c8 JH	455	{
bc1f35b9 JH	456	struct h5 *h5 = hu->priv;
	457	unsigned char *ptr = data;
	458
255a68e0 JH	459	BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
255a68e0 JH	460	count);
bc1f35b9 JH	461
	462	while (count > 0) {
	463	int processed;
	464
	465	if (h5->rx_pending > 0) {
	466	if (*ptr == SLIP_DELIMITER) {
	467	BT_ERR("Too short H5 packet");
	468	h5_reset_rx(h5);
	469	continue;
	470	}
	471
	472	h5_unslip_one_byte(h5, *ptr);
	473
	474	ptr++; count--;
	475	continue;
	476	}
	477
	478	processed = h5->rx_func(hu, *ptr);
	479	if (processed < 0)
	480	return processed;
	481
	482	ptr += processed;
	483	count -= processed;
	484	}
	485
	486	return 0;
7dec65c8 JH	487	}
	488
	489	static int h5_enqueue(struct hci_uart hu, struct sk_buff skb)
	490	{
7d664fba JH	491	struct h5 *h5 = hu->priv;
	492
	493	if (skb->len > 0xfff) {
	494	BT_ERR("Packet too long (%u bytes)", skb->len);
	495	kfree_skb(skb);
	496	return 0;
	497	}
	498
f674a057 JH	499	if (h5->state != H5_ACTIVE) {
	500	BT_ERR("Ignoring HCI data in non-active state");
	501	kfree_skb(skb);
	502	return 0;
	503	}
	504
7d664fba JH	505	switch (bt_cb(skb)->pkt_type) {
	506	case HCI_ACLDATA_PKT:
	507	case HCI_COMMAND_PKT:
	508	skb_queue_tail(&h5->rel, skb);
	509	break;
	510
	511	case HCI_SCODATA_PKT:
	512	skb_queue_tail(&h5->unrel, skb);
	513	break;
	514
	515	default:
	516	BT_ERR("Unknown packet type %u", bt_cb(skb)->pkt_type);
	517	kfree_skb(skb);
	518	break;
	519	}
	520
	521	return 0;
	522	}
	523
c0a1b73c JH	524	static void h5_slip_delim(struct sk_buff *skb)
	525	{
	526	const char delim = SLIP_DELIMITER;
	527
	528	memcpy(skb_put(skb, 1), &delim, 1);
	529	}
	530
	531	static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
	532	{
	533	const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
	534	const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
	535
	536	switch (c) {
	537	case SLIP_DELIMITER:
	538	memcpy(skb_put(skb, 2), &esc_delim, 2);
	539	break;
	540	case SLIP_ESC:
	541	memcpy(skb_put(skb, 2), &esc_esc, 2);
	542	break;
	543	default:
	544	memcpy(skb_put(skb, 1), &c, 1);
	545	}
	546	}
	547
40f10224	548	static struct sk_buff h5_build_pkt(struct hci_uart hu, bool rel, u8 pkt_type,
c0a1b73c	549	const u8 *data, size_t len)
7d664fba	550	{
40f10224	551	struct h5 *h5 = hu->priv;
c0a1b73c JH	552	struct sk_buff *nskb;
	553	u8 hdr[4];
	554	int i;
	555
	556	/*
	557	* Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
	558	* (because bytes 0xc0 and 0xdb are escaped, worst case is when
	559	* the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
	560	* delimiters at start and end).
	561	*/
	562	nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
	563	if (!nskb)
	564	return NULL;
	565
	566	bt_cb(nskb)->pkt_type = pkt_type;
	567
	568	h5_slip_delim(nskb);
	569
40f10224	570	hdr[0] = h5->tx_ack << 3;
43eb12d7	571	h5->tx_ack_req = false;
c0a1b73c JH	572
	573	if (rel) {
	574	hdr[0] \|= 1 << 7;
43eb12d7 JH	575	hdr[0] \|= h5->tx_seq;
43eb12d7 JH	576	h5->tx_seq = (h5->tx_seq + 1) % 8;
c0a1b73c JH	577	}
	578
	579	hdr[1] = pkt_type \| ((len & 0x0f) << 4);
	580	hdr[2] = len >> 4;
	581	hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
	582
40f10224 JH	583	BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
	584	hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
	585	H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
	586	H5_HDR_LEN(hdr));
	587
c0a1b73c JH	588	for (i = 0; i < 4; i++)
	589	h5_slip_one_byte(nskb, hdr[i]);
	590
	591	for (i = 0; i < len; i++)
	592	h5_slip_one_byte(nskb, data[i]);
	593
	594	h5_slip_delim(nskb);
	595
	596	return nskb;
	597	}
	598
40f10224	599	static struct sk_buff h5_prepare_pkt(struct hci_uart hu, u8 pkt_type,
c0a1b73c JH	600	const u8 *data, size_t len)
	601	{
	602	bool rel;
	603
	604	switch (pkt_type) {
	605	case HCI_ACLDATA_PKT:
	606	case HCI_COMMAND_PKT:
	607	rel = true;
	608	break;
	609	case HCI_SCODATA_PKT:
	610	case HCI_3WIRE_LINK_PKT:
	611	case HCI_3WIRE_ACK_PKT:
	612	rel = false;
	613	break;
	614	default:
	615	BT_ERR("Unknown packet type %u", pkt_type);
	616	return NULL;
	617	}
	618
40f10224	619	return h5_build_pkt(hu, rel, pkt_type, data, len);
7dec65c8 JH	620	}
	621
	622	static struct sk_buff h5_dequeue(struct hci_uart hu)
	623	{
7d664fba	624	struct h5 *h5 = hu->priv;
3f27e95b	625	unsigned long flags;
7d664fba JH	626	struct sk_buff skb, nskb;
	627
	628	if ((skb = skb_dequeue(&h5->unrel)) != NULL) {
40f10224	629	nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
c0a1b73c	630	skb->data, skb->len);
7d664fba JH	631	if (nskb) {
	632	kfree_skb(skb);
	633	return nskb;
	634	}
	635
	636	skb_queue_head(&h5->unrel, skb);
	637	BT_ERR("Could not dequeue pkt because alloc_skb failed");
	638	}
	639
3f27e95b JH	640	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
	641
	642	if (h5->unack.qlen >= H5_TXWINSIZE)
	643	goto unlock;
	644
	645	if ((skb = skb_dequeue(&h5->rel)) != NULL) {
40f10224	646	nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
c0a1b73c	647	skb->data, skb->len);
3f27e95b JH	648	if (nskb) {
	649	__skb_queue_tail(&h5->unack, skb);
	650	mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
	651	spin_unlock_irqrestore(&h5->unack.lock, flags);
	652	return nskb;
	653	}
	654
	655	skb_queue_head(&h5->rel, skb);
	656	BT_ERR("Could not dequeue pkt because alloc_skb failed");
	657	}
	658
	659	unlock:
	660	spin_unlock_irqrestore(&h5->unack.lock, flags);
	661
43eb12d7	662	if (h5->tx_ack_req)
40f10224	663	return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
7d664fba	664
7dec65c8 JH	665	return NULL;
	666	}
	667
	668	static int h5_flush(struct hci_uart *hu)
	669	{
7d664fba JH	670	BT_DBG("hu %p", hu);
7d664fba JH	671	return 0;
7dec65c8 JH	672	}
	673
	674	static struct hci_uart_proto h5p = {
	675	.id = HCI_UART_3WIRE,
	676	.open = h5_open,
	677	.close = h5_close,
	678	.recv = h5_recv,
	679	.enqueue = h5_enqueue,
	680	.dequeue = h5_dequeue,
	681	.flush = h5_flush,
	682	};
	683
	684	int __init h5_init(void)
	685	{
	686	int err = hci_uart_register_proto(&h5p);
	687
	688	if (!err)
	689	BT_INFO("HCI Three-wire UART (H5) protocol initialized");
	690	else
	691	BT_ERR("HCI Three-wire UART (H5) protocol init failed");
	692
	693	return err;
	694	}
	695
	696	int __exit h5_deinit(void)
	697	{
	698	return hci_uart_unregister_proto(&h5p);
	699	}