[GitHub/mt8127/android_kernel_alcatel_ttab.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

/* Sliding window size */
#define H5_TX_WIN_MAX		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

/* H5 state flags */
enum {
	H5_RX_ESC,	/* SLIP escape mode */
	H5_TX_ACK_REQ,	/* Pending ack to send */
};

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 */

	unsigned long		flags;

	struct sk_buff		*rx_skb;	/* Receive buffer */
	size_t			rx_pending;	/* Expecting more bytes */
	u8			rx_ack;		/* Last ack number received */

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

	struct timer_list	timer;		/* Retransmission timer */

	u8			tx_seq;		/* Next seq number to send */
	u8			tx_ack;		/* Next ack number to send */
	u8			tx_win;		/* Sliding window size */

	enum {
		H5_UNINITIALIZED,
		H5_INITIALIZED,
		H5_ACTIVE,
	} state;

	enum {
		H5_AWAKE,
		H5_SLEEPING,
		H5_WAKING_UP,
	} sleep;
};

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 u8 h5_cfg_field(struct h5 *h5)
{
	u8 field = 0;

	/* Sliding window size (first 3 bits) */
	field |= (h5->tx_win & 7);

	return field;
}

static void h5_timed_event(unsigned long arg)
{
	const unsigned char sync_req[] = { 0x01, 0x7e };
	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;

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

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

	if (h5->state == H5_INITIALIZED) {
		conf_req[2] = h5_cfg_field(h5);
		h5_link_control(hu, conf_req, sizeof(conf_req));
	}

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

	if (h5->sleep != H5_AWAKE) {
		h5->sleep = H5_SLEEPING;
		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;

	h5->tx_win = H5_TX_WIN_MAX;

	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 };
	unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
	const unsigned char conf_rsp[] = { 0x04, 0x7b };
	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;

	conf_req[2] = h5_cfg_field(h5);

	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) {
		if (H5_HDR_LEN(hdr) > 2)
			h5->tx_win = (data[2] & 7);
		BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
		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->sleep = H5_SLEEPING;
		return;
	} else if (memcmp(data, woken_req, 2) == 0) {
		BT_DBG("Peer woke up");
		h5->sleep = H5_AWAKE;
	} else if (memcmp(data, wakeup_req, 2) == 0) {
		BT_DBG("Peer requested wakeup");
		h5_link_control(hu, woken_req, 2);
		h5->sleep = H5_AWAKE;
	} 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;
		set_bit(H5_TX_ACK_REQ, &h5->flags);
		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 (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
		set_bit(H5_RX_ESC, &h5->flags);
		return;
	}

	if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
		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;
		}
	}

	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;
	clear_bit(H5_RX_ESC, &h5->flags);
}

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 bool valid_packet_type(u8 type)
{
	switch (type) {
	case HCI_ACLDATA_PKT:
	case HCI_COMMAND_PKT:
	case HCI_SCODATA_PKT:
	case HCI_3WIRE_LINK_PKT:
	case HCI_3WIRE_ACK_PKT:
		return true;
	default:
		return false;
	}
}

static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
				      const u8 *data, size_t len)
{
	struct h5 *h5 = hu->priv;
	struct sk_buff *nskb;
	u8 hdr[4];
	int i;

	if (!valid_packet_type(pkt_type)) {
		BT_ERR("Unknown packet type %u", pkt_type);
		return NULL;
	}

	/*
	 * 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;
	clear_bit(H5_TX_ACK_REQ, &h5->flags);

	/* Reliable packet? */
	if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
		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_dequeue(struct hci_uart *hu)
{
	struct h5 *h5 = hu->priv;
	unsigned long flags;
	struct sk_buff *skb, *nskb;

	if (h5->sleep != H5_AWAKE) {
		const unsigned char wakeup_req[] = { 0x05, 0xfa };

		if (h5->sleep == H5_WAKING_UP)
			return NULL;

		h5->sleep = H5_WAKING_UP;
		BT_DBG("Sending wakeup request");

		mod_timer(&h5->timer, jiffies + HZ / 100);
		return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
	}

	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->tx_win)
		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 (test_bit(H5_TX_ACK_REQ, &h5->flags))
		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
afdc944c JH	36	/* Sliding window size */
afdc944c JH	37	#define H5_TX_WIN_MAX 4
3f27e95b JH	38
3f27e95b JH	39	#define H5_ACK_TIMEOUT msecs_to_jiffies(250)
40f10224	40	#define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
3f27e95b	41
bc1f35b9 JH	42	/*
	43	* Maximum Three-wire packet:
	44	* 4 byte header + max value for 12-bit length + 2 bytes for CRC
	45	*/
	46	#define H5_MAX_LEN (4 + 0xfff + 2)
	47
01977c0b JH	48	/* Convenience macros for reading Three-wire header values */
	49	#define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07)
	50	#define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07)
	51	#define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01)
	52	#define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01)
	53	#define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f)
	54	#define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0xff) + ((hdr)[2] << 4))
	55
bc1f35b9 JH	56	#define SLIP_DELIMITER 0xc0
	57	#define SLIP_ESC 0xdb
	58	#define SLIP_ESC_DELIM 0xdc
	59	#define SLIP_ESC_ESC 0xdd
	60
e0482103 JH	61	/* H5 state flags */
	62	enum {
	63	H5_RX_ESC, /* SLIP escape mode */
	64	H5_TX_ACK_REQ, /* Pending ack to send */
	65	};
	66
7d664fba	67	struct h5 {
bc1f35b9 JH	68	struct sk_buff_head unack; /* Unack'ed packets queue */
	69	struct sk_buff_head rel; /* Reliable packets queue */
	70	struct sk_buff_head unrel; /* Unreliable packets queue */
	71
e0482103 JH	72	unsigned long flags;
e0482103 JH	73
bc1f35b9 JH	74	struct sk_buff rx_skb; / Receive buffer */
bc1f35b9 JH	75	size_t rx_pending; /* Expecting more bytes */
43eb12d7	76	u8 rx_ack; /* Last ack number received */
7d664fba	77
bc1f35b9	78	int (rx_func) (struct hci_uart hu, u8 c);
7d664fba	79
bc1f35b9	80	struct timer_list timer; /* Retransmission timer */
3f27e95b	81
43eb12d7	82	u8 tx_seq; /* Next seq number to send */
40f10224	83	u8 tx_ack; /* Next ack number to send */
afdc944c	84	u8 tx_win; /* Sliding window size */
10122d07	85
f674a057 JH	86	enum {
	87	H5_UNINITIALIZED,
	88	H5_INITIALIZED,
	89	H5_ACTIVE,
	90	} state;
	91
95c5c220 JH	92	enum {
	93	H5_AWAKE,
	94	H5_SLEEPING,
	95	H5_WAKING_UP,
	96	} sleep;
7d664fba JH	97	};
7d664fba JH	98
bc1f35b9 JH	99	static void h5_reset_rx(struct h5 *h5);
bc1f35b9 JH	100
f674a057 JH	101	static void h5_link_control(struct hci_uart hu, const void data, size_t len)
	102	{
	103	struct h5 *h5 = hu->priv;
	104	struct sk_buff *nskb;
	105
	106	nskb = alloc_skb(3, GFP_ATOMIC);
	107	if (!nskb)
	108	return;
	109
	110	bt_cb(nskb)->pkt_type = HCI_3WIRE_LINK_PKT;
	111
	112	memcpy(skb_put(nskb, len), data, len);
	113
	114	skb_queue_tail(&h5->unrel, nskb);
	115	}
	116
afdc944c JH	117	static u8 h5_cfg_field(struct h5 *h5)
	118	{
	119	u8 field = 0;
	120
	121	/* Sliding window size (first 3 bits) */
	122	field \|= (h5->tx_win & 7);
	123
	124	return field;
	125	}
	126
3f27e95b JH	127	static void h5_timed_event(unsigned long arg)
3f27e95b JH	128	{
f674a057	129	const unsigned char sync_req[] = { 0x01, 0x7e };
afdc944c	130	unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
3f27e95b JH	131	struct hci_uart hu = (struct hci_uart ) arg;
	132	struct h5 *h5 = hu->priv;
	133	struct sk_buff *skb;
	134	unsigned long flags;
	135
95c5c220 JH	136	BT_DBG("%s", hu->hdev->name);
95c5c220 JH	137
f674a057 JH	138	if (h5->state == H5_UNINITIALIZED)
	139	h5_link_control(hu, sync_req, sizeof(sync_req));
	140
afdc944c JH	141	if (h5->state == H5_INITIALIZED) {
afdc944c JH	142	conf_req[2] = h5_cfg_field(h5);
f674a057	143	h5_link_control(hu, conf_req, sizeof(conf_req));
afdc944c	144	}
f674a057 JH	145
	146	if (h5->state != H5_ACTIVE) {
	147	mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
	148	goto wakeup;
	149	}
	150
95c5c220 JH	151	if (h5->sleep != H5_AWAKE) {
	152	h5->sleep = H5_SLEEPING;
	153	goto wakeup;
	154	}
	155
3f27e95b JH	156	BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
	157
	158	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
	159
	160	while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
43eb12d7	161	h5->tx_seq = (h5->tx_seq - 1) & 0x07;
3f27e95b JH	162	skb_queue_head(&h5->rel, skb);
	163	}
	164
	165	spin_unlock_irqrestore(&h5->unack.lock, flags);
	166
f674a057	167	wakeup:
3f27e95b JH	168	hci_uart_tx_wakeup(hu);
	169	}
	170
7dec65c8 JH	171	static int h5_open(struct hci_uart *hu)
7dec65c8 JH	172	{
7d664fba	173	struct h5 *h5;
40f10224	174	const unsigned char sync[] = { 0x01, 0x7e };
7d664fba JH	175
	176	BT_DBG("hu %p", hu);
	177
	178	h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
	179	if (!h5)
	180	return -ENOMEM;
	181
	182	hu->priv = h5;
	183
	184	skb_queue_head_init(&h5->unack);
	185	skb_queue_head_init(&h5->rel);
	186	skb_queue_head_init(&h5->unrel);
	187
bc1f35b9 JH	188	h5_reset_rx(h5);
bc1f35b9 JH	189
3f27e95b JH	190	init_timer(&h5->timer);
	191	h5->timer.function = h5_timed_event;
	192	h5->timer.data = (unsigned long) hu;
	193
afdc944c JH	194	h5->tx_win = H5_TX_WIN_MAX;
afdc944c JH	195
cd1b4425 JH	196	set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
cd1b4425 JH	197
40f10224 JH	198	/* Send initial sync request */
	199	h5_link_control(hu, sync, sizeof(sync));
	200	mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
	201
7d664fba	202	return 0;
7dec65c8 JH	203	}
	204
	205	static int h5_close(struct hci_uart *hu)
	206	{
7d664fba JH	207	struct h5 *h5 = hu->priv;
	208
	209	skb_queue_purge(&h5->unack);
	210	skb_queue_purge(&h5->rel);
	211	skb_queue_purge(&h5->unrel);
	212
3f27e95b JH	213	del_timer(&h5->timer);
3f27e95b JH	214
7d664fba JH	215	kfree(h5);
	216
	217	return 0;
7dec65c8 JH	218	}
7dec65c8 JH	219
43eb12d7 JH	220	static void h5_pkt_cull(struct h5 *h5)
	221	{
	222	struct sk_buff skb, tmp;
	223	unsigned long flags;
	224	int i, to_remove;
	225	u8 seq;
	226
	227	spin_lock_irqsave(&h5->unack.lock, flags);
	228
	229	to_remove = skb_queue_len(&h5->unack);
40f10224 JH	230	if (to_remove == 0)
40f10224 JH	231	goto unlock;
43eb12d7 JH	232
	233	seq = h5->tx_seq;
	234
	235	while (to_remove > 0) {
	236	if (h5->rx_ack == seq)
	237	break;
	238
	239	to_remove--;
	240	seq = (seq - 1) % 8;
	241	}
	242
	243	if (seq != h5->rx_ack)
	244	BT_ERR("Controller acked invalid packet");
	245
	246	i = 0;
	247	skb_queue_walk_safe(&h5->unack, skb, tmp) {
	248	if (i++ >= to_remove)
	249	break;
	250
	251	__skb_unlink(skb, &h5->unack);
	252	kfree_skb(skb);
	253	}
	254
	255	if (skb_queue_empty(&h5->unack))
	256	del_timer(&h5->timer);
	257
40f10224	258	unlock:
43eb12d7 JH	259	spin_unlock_irqrestore(&h5->unack.lock, flags);
	260	}
	261
bc1f35b9 JH	262	static void h5_handle_internal_rx(struct hci_uart *hu)
bc1f35b9 JH	263	{
40f10224 JH	264	struct h5 *h5 = hu->priv;
	265	const unsigned char sync_req[] = { 0x01, 0x7e };
	266	const unsigned char sync_rsp[] = { 0x02, 0x7d };
afdc944c JH	267	unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
afdc944c JH	268	const unsigned char conf_rsp[] = { 0x04, 0x7b };
10122d07 JH	269	const unsigned char wakeup_req[] = { 0x05, 0xfa };
	270	const unsigned char woken_req[] = { 0x06, 0xf9 };
	271	const unsigned char sleep_req[] = { 0x07, 0x78 };
40f10224 JH	272	const unsigned char *hdr = h5->rx_skb->data;
	273	const unsigned char *data = &h5->rx_skb->data[4];
	274
bc1f35b9	275	BT_DBG("%s", hu->hdev->name);
40f10224 JH	276
	277	if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
	278	return;
	279
	280	if (H5_HDR_LEN(hdr) < 2)
	281	return;
	282
afdc944c JH	283	conf_req[2] = h5_cfg_field(h5);
afdc944c JH	284
40f10224 JH	285	if (memcmp(data, sync_req, 2) == 0) {
	286	h5_link_control(hu, sync_rsp, 2);
	287	} else if (memcmp(data, sync_rsp, 2) == 0) {
f674a057	288	h5->state = H5_INITIALIZED;
40f10224 JH	289	h5_link_control(hu, conf_req, 3);
	290	} else if (memcmp(data, conf_req, 2) == 0) {
	291	h5_link_control(hu, conf_rsp, 2);
	292	h5_link_control(hu, conf_req, 3);
	293	} else if (memcmp(data, conf_rsp, 2) == 0) {
afdc944c JH	294	if (H5_HDR_LEN(hdr) > 2)
	295	h5->tx_win = (data[2] & 7);
	296	BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
f674a057	297	h5->state = H5_ACTIVE;
cd1b4425	298	hci_uart_init_ready(hu);
40f10224	299	return;
10122d07 JH	300	} else if (memcmp(data, sleep_req, 2) == 0) {
10122d07 JH	301	BT_DBG("Peer went to sleep");
95c5c220 JH	302	h5->sleep = H5_SLEEPING;
95c5c220 JH	303	return;
10122d07 JH	304	} else if (memcmp(data, woken_req, 2) == 0) {
10122d07 JH	305	BT_DBG("Peer woke up");
95c5c220 JH	306	h5->sleep = H5_AWAKE;
	307	} else if (memcmp(data, wakeup_req, 2) == 0) {
	308	BT_DBG("Peer requested wakeup");
	309	h5_link_control(hu, woken_req, 2);
	310	h5->sleep = H5_AWAKE;
40f10224 JH	311	} else {
	312	BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
	313	return;
	314	}
	315
	316	hci_uart_tx_wakeup(hu);
bc1f35b9 JH	317	}
	318
	319	static void h5_complete_rx_pkt(struct hci_uart *hu)
	320	{
	321	struct h5 *h5 = hu->priv;
43eb12d7	322	const unsigned char *hdr = h5->rx_skb->data;
bc1f35b9	323
43eb12d7	324	if (H5_HDR_RELIABLE(hdr)) {
40f10224	325	h5->tx_ack = (h5->tx_ack + 1) % 8;
e0482103	326	set_bit(H5_TX_ACK_REQ, &h5->flags);
40f10224	327	hci_uart_tx_wakeup(hu);
43eb12d7	328	}
bc1f35b9	329
43eb12d7 JH	330	h5->rx_ack = H5_HDR_ACK(hdr);
	331
	332	h5_pkt_cull(h5);
	333
	334	switch (H5_HDR_PKT_TYPE(hdr)) {
bc1f35b9 JH	335	case HCI_EVENT_PKT:
	336	case HCI_ACLDATA_PKT:
	337	case HCI_SCODATA_PKT:
43eb12d7	338	bt_cb(h5->rx_skb)->pkt_type = H5_HDR_PKT_TYPE(hdr);
bc1f35b9 JH	339
	340	/* Remove Three-wire header */
	341	skb_pull(h5->rx_skb, 4);
	342
	343	hci_recv_frame(h5->rx_skb);
	344	h5->rx_skb = NULL;
	345
	346	break;
	347
	348	default:
	349	h5_handle_internal_rx(hu);
	350	break;
	351	}
	352
	353	h5_reset_rx(h5);
	354	}
	355
	356	static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
	357	{
	358	struct h5 *h5 = hu->priv;
	359
bc1f35b9 JH	360	h5_complete_rx_pkt(hu);
	361	h5_reset_rx(h5);
	362
	363	return 0;
	364	}
	365
	366	static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
	367	{
	368	struct h5 *h5 = hu->priv;
	369	const unsigned char *hdr = h5->rx_skb->data;
	370
43eb12d7	371	if (H5_HDR_CRC(hdr)) {
bc1f35b9 JH	372	h5->rx_func = h5_rx_crc;
	373	h5->rx_pending = 2;
	374	} else {
	375	h5_complete_rx_pkt(hu);
	376	h5_reset_rx(h5);
	377	}
	378
	379	return 0;
	380	}
	381
	382	static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
	383	{
	384	struct h5 *h5 = hu->priv;
	385	const unsigned char *hdr = h5->rx_skb->data;
	386
40f10224 JH	387	BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
	388	hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
	389	H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
	390	H5_HDR_LEN(hdr));
	391
bc1f35b9 JH	392	if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
	393	BT_ERR("Invalid header checksum");
	394	h5_reset_rx(h5);
	395	return 0;
	396	}
	397
40f10224	398	if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
43eb12d7	399	BT_ERR("Out-of-order packet arrived (%u != %u)",
40f10224	400	H5_HDR_SEQ(hdr), h5->tx_ack);
43eb12d7 JH	401	h5_reset_rx(h5);
	402	return 0;
	403	}
	404
f674a057 JH	405	if (h5->state != H5_ACTIVE &&
	406	H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
	407	BT_ERR("Non-link packet received in non-active state");
	408	h5_reset_rx(h5);
	409	}
	410
bc1f35b9	411	h5->rx_func = h5_rx_payload;
43eb12d7	412	h5->rx_pending = H5_HDR_LEN(hdr);
bc1f35b9 JH	413
	414	return 0;
	415	}
	416
	417	static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
	418	{
	419	struct h5 *h5 = hu->priv;
	420
bc1f35b9 JH	421	if (c == SLIP_DELIMITER)
	422	return 1;
	423
	424	h5->rx_func = h5_rx_3wire_hdr;
	425	h5->rx_pending = 4;
	426
	427	h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
	428	if (!h5->rx_skb) {
	429	BT_ERR("Can't allocate mem for new packet");
	430	h5_reset_rx(h5);
	431	return -ENOMEM;
	432	}
	433
	434	h5->rx_skb->dev = (void *) hu->hdev;
	435
	436	return 0;
	437	}
	438
	439	static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
	440	{
	441	struct h5 *h5 = hu->priv;
	442
bc1f35b9 JH	443	if (c == SLIP_DELIMITER)
	444	h5->rx_func = h5_rx_pkt_start;
	445
	446	return 1;
	447	}
	448
	449	static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
	450	{
	451	const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
	452	const u8 *byte = &c;
	453
e0482103 JH	454	if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
e0482103 JH	455	set_bit(H5_RX_ESC, &h5->flags);
bc1f35b9 JH	456	return;
	457	}
	458
e0482103	459	if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
bc1f35b9 JH	460	switch (c) {
	461	case SLIP_ESC_DELIM:
	462	byte = &delim;
	463	break;
	464	case SLIP_ESC_ESC:
	465	byte = &esc;
	466	break;
	467	default:
	468	BT_ERR("Invalid esc byte 0x%02hhx", c);
	469	h5_reset_rx(h5);
	470	return;
	471	}
bc1f35b9 JH	472	}
	473
	474	memcpy(skb_put(h5->rx_skb, 1), byte, 1);
	475	h5->rx_pending--;
	476
255a68e0	477	BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
bc1f35b9 JH	478	}
	479
	480	static void h5_reset_rx(struct h5 *h5)
	481	{
	482	if (h5->rx_skb) {
	483	kfree_skb(h5->rx_skb);
	484	h5->rx_skb = NULL;
	485	}
	486
	487	h5->rx_func = h5_rx_delimiter;
	488	h5->rx_pending = 0;
e0482103	489	clear_bit(H5_RX_ESC, &h5->flags);
bc1f35b9 JH	490	}
bc1f35b9 JH	491
7dec65c8 JH	492	static int h5_recv(struct hci_uart hu, void data, int count)
7dec65c8 JH	493	{
bc1f35b9 JH	494	struct h5 *h5 = hu->priv;
	495	unsigned char *ptr = data;
	496
255a68e0 JH	497	BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
255a68e0 JH	498	count);
bc1f35b9 JH	499
	500	while (count > 0) {
	501	int processed;
	502
	503	if (h5->rx_pending > 0) {
	504	if (*ptr == SLIP_DELIMITER) {
	505	BT_ERR("Too short H5 packet");
	506	h5_reset_rx(h5);
	507	continue;
	508	}
	509
	510	h5_unslip_one_byte(h5, *ptr);
	511
	512	ptr++; count--;
	513	continue;
	514	}
	515
	516	processed = h5->rx_func(hu, *ptr);
	517	if (processed < 0)
	518	return processed;
	519
	520	ptr += processed;
	521	count -= processed;
	522	}
	523
	524	return 0;
7dec65c8 JH	525	}
	526
	527	static int h5_enqueue(struct hci_uart hu, struct sk_buff skb)
	528	{
7d664fba JH	529	struct h5 *h5 = hu->priv;
	530
	531	if (skb->len > 0xfff) {
	532	BT_ERR("Packet too long (%u bytes)", skb->len);
	533	kfree_skb(skb);
	534	return 0;
	535	}
	536
f674a057 JH	537	if (h5->state != H5_ACTIVE) {
	538	BT_ERR("Ignoring HCI data in non-active state");
	539	kfree_skb(skb);
	540	return 0;
	541	}
	542
7d664fba JH	543	switch (bt_cb(skb)->pkt_type) {
	544	case HCI_ACLDATA_PKT:
	545	case HCI_COMMAND_PKT:
	546	skb_queue_tail(&h5->rel, skb);
	547	break;
	548
	549	case HCI_SCODATA_PKT:
	550	skb_queue_tail(&h5->unrel, skb);
	551	break;
	552
	553	default:
	554	BT_ERR("Unknown packet type %u", bt_cb(skb)->pkt_type);
	555	kfree_skb(skb);
	556	break;
	557	}
	558
	559	return 0;
	560	}
	561
c0a1b73c JH	562	static void h5_slip_delim(struct sk_buff *skb)
	563	{
	564	const char delim = SLIP_DELIMITER;
	565
	566	memcpy(skb_put(skb, 1), &delim, 1);
	567	}
	568
	569	static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
	570	{
	571	const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
	572	const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
	573
	574	switch (c) {
	575	case SLIP_DELIMITER:
	576	memcpy(skb_put(skb, 2), &esc_delim, 2);
	577	break;
	578	case SLIP_ESC:
	579	memcpy(skb_put(skb, 2), &esc_esc, 2);
	580	break;
	581	default:
	582	memcpy(skb_put(skb, 1), &c, 1);
	583	}
	584	}
	585
c826ed09 JH	586	static bool valid_packet_type(u8 type)
	587	{
	588	switch (type) {
	589	case HCI_ACLDATA_PKT:
	590	case HCI_COMMAND_PKT:
	591	case HCI_SCODATA_PKT:
	592	case HCI_3WIRE_LINK_PKT:
	593	case HCI_3WIRE_ACK_PKT:
	594	return true;
	595	default:
	596	return false;
	597	}
	598	}
	599
	600	static struct sk_buff h5_prepare_pkt(struct hci_uart hu, u8 pkt_type,
	601	const u8 *data, size_t len)
7d664fba	602	{
40f10224	603	struct h5 *h5 = hu->priv;
c0a1b73c JH	604	struct sk_buff *nskb;
	605	u8 hdr[4];
	606	int i;
	607
c826ed09 JH	608	if (!valid_packet_type(pkt_type)) {
	609	BT_ERR("Unknown packet type %u", pkt_type);
	610	return NULL;
	611	}
	612
c0a1b73c JH	613	/*
	614	* Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
	615	* (because bytes 0xc0 and 0xdb are escaped, worst case is when
	616	* the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
	617	* delimiters at start and end).
	618	*/
	619	nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
	620	if (!nskb)
	621	return NULL;
	622
	623	bt_cb(nskb)->pkt_type = pkt_type;
	624
	625	h5_slip_delim(nskb);
	626
40f10224	627	hdr[0] = h5->tx_ack << 3;
e0482103	628	clear_bit(H5_TX_ACK_REQ, &h5->flags);
c0a1b73c	629
c826ed09 JH	630	/* Reliable packet? */
c826ed09 JH	631	if (pkt_type == HCI_ACLDATA_PKT \|\| pkt_type == HCI_COMMAND_PKT) {
c0a1b73c	632	hdr[0] \|= 1 << 7;
43eb12d7 JH	633	hdr[0] \|= h5->tx_seq;
43eb12d7 JH	634	h5->tx_seq = (h5->tx_seq + 1) % 8;
c0a1b73c JH	635	}
	636
	637	hdr[1] = pkt_type \| ((len & 0x0f) << 4);
	638	hdr[2] = len >> 4;
	639	hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
	640
40f10224 JH	641	BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
	642	hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
	643	H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
	644	H5_HDR_LEN(hdr));
	645
c0a1b73c JH	646	for (i = 0; i < 4; i++)
	647	h5_slip_one_byte(nskb, hdr[i]);
	648
	649	for (i = 0; i < len; i++)
	650	h5_slip_one_byte(nskb, data[i]);
	651
	652	h5_slip_delim(nskb);
	653
	654	return nskb;
	655	}
	656
7dec65c8 JH	657	static struct sk_buff h5_dequeue(struct hci_uart hu)
7dec65c8 JH	658	{
7d664fba	659	struct h5 *h5 = hu->priv;
3f27e95b	660	unsigned long flags;
7d664fba JH	661	struct sk_buff skb, nskb;
7d664fba JH	662
95c5c220 JH	663	if (h5->sleep != H5_AWAKE) {
	664	const unsigned char wakeup_req[] = { 0x05, 0xfa };
	665
	666	if (h5->sleep == H5_WAKING_UP)
	667	return NULL;
	668
	669	h5->sleep = H5_WAKING_UP;
	670	BT_DBG("Sending wakeup request");
	671
	672	mod_timer(&h5->timer, jiffies + HZ / 100);
	673	return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
	674	}
	675
7d664fba	676	if ((skb = skb_dequeue(&h5->unrel)) != NULL) {
40f10224	677	nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
c0a1b73c	678	skb->data, skb->len);
7d664fba JH	679	if (nskb) {
	680	kfree_skb(skb);
	681	return nskb;
	682	}
	683
	684	skb_queue_head(&h5->unrel, skb);
	685	BT_ERR("Could not dequeue pkt because alloc_skb failed");
	686	}
	687
3f27e95b JH	688	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
3f27e95b JH	689
afdc944c	690	if (h5->unack.qlen >= h5->tx_win)
3f27e95b JH	691	goto unlock;
	692
	693	if ((skb = skb_dequeue(&h5->rel)) != NULL) {
40f10224	694	nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
c0a1b73c	695	skb->data, skb->len);
3f27e95b JH	696	if (nskb) {
	697	__skb_queue_tail(&h5->unack, skb);
	698	mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
	699	spin_unlock_irqrestore(&h5->unack.lock, flags);
	700	return nskb;
	701	}
	702
	703	skb_queue_head(&h5->rel, skb);
	704	BT_ERR("Could not dequeue pkt because alloc_skb failed");
	705	}
	706
	707	unlock:
	708	spin_unlock_irqrestore(&h5->unack.lock, flags);
	709
e0482103	710	if (test_bit(H5_TX_ACK_REQ, &h5->flags))
40f10224	711	return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
7d664fba	712
7dec65c8 JH	713	return NULL;
	714	}
	715
	716	static int h5_flush(struct hci_uart *hu)
	717	{
7d664fba JH	718	BT_DBG("hu %p", hu);
7d664fba JH	719	return 0;
7dec65c8 JH	720	}
	721
	722	static struct hci_uart_proto h5p = {
	723	.id = HCI_UART_3WIRE,
	724	.open = h5_open,
	725	.close = h5_close,
	726	.recv = h5_recv,
	727	.enqueue = h5_enqueue,
	728	.dequeue = h5_dequeue,
	729	.flush = h5_flush,
	730	};
	731
	732	int __init h5_init(void)
	733	{
	734	int err = hci_uart_register_proto(&h5p);
	735
	736	if (!err)
	737	BT_INFO("HCI Three-wire UART (H5) protocol initialized");
	738	else
	739	BT_ERR("HCI Three-wire UART (H5) protocol init failed");
	740
	741	return err;
	742	}
	743
	744	int __exit h5_deinit(void)
	745	{
	746	return hci_uart_unregister_proto(&h5p);
	747	}