bfusb.c

HCI USB driver for Linux Bluetooth protocol stack

/*
 *
 *  AVM BlueFRITZ! USB driver
 *
 *  Copyright (C) 2003-2006  Marcel Holtmann <[e-mail]>
 *
 *
 *  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/module.h>

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/skbuff.h>

#include <linux/device.h>
#include <linux/firmware.h>

#include <linux/usb.h>

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

#ifndef CONFIG_BT_HCIBFUSB_DEBUG
#undef  BT_DBG
#define BT_DBG(D...)
#endif

#define VERSION "1.1"

static int ignore = 0;

static struct usb_driver bfusb_driver;

static struct usb_device_id bfusb_table[] = {
	/* AVM BlueFRITZ! USB */
	{ USB_DEVICE(0x057c, 0x2200) },

	{ }	/* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, bfusb_table);

#define BFUSB_MAX_BLOCK_SIZE	256

#define BFUSB_BLOCK_TIMEOUT	3000

#define BFUSB_TX_PROCESS	1
#define BFUSB_TX_WAKEUP		2

#define BFUSB_MAX_BULK_TX	2
#define BFUSB_MAX_BULK_RX	2

struct bfusb_data {
	struct hci_dev		*hdev;

	unsigned long		state;

	struct usb_device	*udev;

	unsigned int		bulk_in_ep;
	unsigned int		bulk_out_ep;
	unsigned int		bulk_pkt_size;

	rwlock_t		lock;

	struct sk_buff_head	transmit_q;

	struct sk_buff		*reassembly;

	atomic_t		pending_tx;
	struct sk_buff_head	pending_q;
	struct sk_buff_head	completed_q;
};

struct bfusb_data_scb {
	struct urb *urb;
};

static void bfusb_tx_complete(struct urb *urb);
static void bfusb_rx_complete(struct urb *urb);

static struct urb *bfusb_get_completed(struct bfusb_data *data)
{
	struct sk_buff *skb;
	struct urb *urb = NULL;

	BT_DBG("bfusb %p", data);

	skb = skb_dequeue(&data->completed_q);
	if (skb) {
		urb = ((struct bfusb_data_scb *) skb->cb)->urb;
		kfree_skb(skb);
	}

	return urb;
}

static void bfusb_unlink_urbs(struct bfusb_data *data)
{
	struct sk_buff *skb;
	struct urb *urb;

	BT_DBG("bfusb %p", data);

	while ((skb = skb_dequeue(&data->pending_q))) {
		urb = ((struct bfusb_data_scb *) skb->cb)->urb;
		usb_kill_urb(urb);
		skb_queue_tail(&data->completed_q, skb);
	}

	while ((urb = bfusb_get_completed(data)))
		usb_free_urb(urb);
}

static int bfusb_send_bulk(struct bfusb_data *data, struct sk_buff *skb)
{
	struct bfusb_data_scb *scb = (void *) skb->cb;
	struct urb *urb = bfusb_get_completed(data);
	int err, pipe;

	BT_DBG("bfusb %p skb %p len %d", data, skb, skb->len);

	if (!urb && !(urb = usb_alloc_urb(0, GFP_ATOMIC)))
		return -ENOMEM;

	pipe = usb_sndbulkpipe(data->udev, data->bulk_out_ep);

	usb_fill_bulk_urb(urb, data->udev, pipe, skb->data, skb->len,
			bfusb_tx_complete, skb);

	scb->urb = urb;

	skb_queue_tail(&data->pending_q, skb);

	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err) {
		BT_ERR("%s bulk tx submit failed urb %p err %d", 
					data->hdev->name, urb, err);
		skb_unlink(skb, &data->pending_q);
		usb_free_urb(urb);
	} else
		atomic_inc(&data->pending_tx);

	return err;
}

static void bfusb_tx_wakeup(struct bfusb_data *data)
{
	struct sk_buff *skb;

	BT_DBG("bfusb %p", data);

	if (test_and_set_bit(BFUSB_TX_PROCESS, &data->state)) {
		set_bit(BFUSB_TX_WAKEUP, &data->state);
		return;
	}

	do {
		clear_bit(BFUSB_TX_WAKEUP, &data->state);

		while ((atomic_read(&data->pending_tx) < BFUSB_MAX_BULK_TX) &&
				(skb = skb_dequeue(&data->transmit_q))) {
			if (bfusb_send_bulk(data, skb) < 0) {
				skb_queue_head(&data->transmit_q, skb);
				break;
			}
		}

	} while (test_bit(BFUSB_TX_WAKEUP, &data->state));

	clear_bit(BFUSB_TX_PROCESS, &data->state);
}

static void bfusb_tx_complete(struct urb *urb)
{
	struct sk_buff *skb = (struct sk_buff *) urb->context;
	struct bfusb_data *data = (struct bfusb_data *) skb->dev;

	BT_DBG("bfusb %p urb %p skb %p len %d", data, urb, skb, skb->len);

	atomic_dec(&data->pending_tx);

	if (!test_bit(HCI_RUNNING, &data->hdev->flags))
		return;

	if (!urb->status)
		data->hdev->stat.byte_tx += skb->len;
	else
		data->hdev->stat.err_tx++;

	read_lock(&data->lock);

	skb_unlink(skb, &data->pending_q);
	skb_queue_tail(&data->completed_q, skb);

	bfusb_tx_wakeup(data);

	read_unlock(&data->lock);
}


static int bfusb_rx_submit(struct bfusb_data *data, struct urb *urb)
{
	struct bfusb_data_scb *scb;
	struct sk_buff *skb;
	int err, pipe, size = HCI_MAX_FRAME_SIZE + 32;

	BT_DBG("bfusb %p urb %p", bfusb, urb);

	if (!urb && !(urb = usb_alloc_urb(0, GFP_ATOMIC)))
		return -ENOMEM;

	skb = bt_skb_alloc(size, GFP_ATOMIC);
	if (!skb) {
		usb_free_urb(urb);
		return -ENOMEM;
	}

	skb->dev = (void *) data;

	scb = (struct bfusb_data_scb *) skb->cb;
	scb->urb = urb;

	pipe = usb_rcvbulkpipe(data->udev, data->bulk_in_ep);

	usb_fill_bulk_urb(urb, data->udev, pipe, skb->data, size,
			bfusb_rx_complete, skb);

	skb_queue_tail(&data->pending_q, skb);

	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err) {
		BT_ERR("%s bulk rx submit failed urb %p err %d",
					data->hdev->name, urb, err);
		skb_unlink(skb, &data->pending_q);
		kfree_skb(skb);
		usb_free_urb(urb);
	}

	return err;
}

static inline int bfusb_recv_block(struct bfusb_data *data, int hdr, unsigned char *buf, int len)
{
	BT_DBG("bfusb %p hdr 0x%02x data %p len %d", data, hdr, buf, len);

	if (hdr & 0x10) {
		BT_ERR("%s error in block", data->hdev->name);
		if (data->reassembly)
			kfree_skb(data->reassembly);
		data->reassembly = NULL;
		return -EIO;
	}

	if (hdr & 0x04) {
		struct sk_buff *skb;
		unsigned char pkt_type;
		int pkt_len = 0;

		if (data->reassembly) {
			BT_ERR("%s unexpected start block", data->hdev->name);
			kfree_skb(data->reassembly);
			data->reassembly = NULL;
		}

		if (len < 1) {
			BT_ERR("%s no packet type found", data->hdev->name);
			return -EPROTO;
		}

		pkt_type = *buf++; len--;

		switch (pkt_type) {
		case HCI_EVENT_PKT:
			if (len >= HCI_EVENT_HDR_SIZE) {
				struct hci_event_hdr *hdr = (struct hci_event_hdr *) buf;
				pkt_len = HCI_EVENT_HDR_SIZE + hdr->plen;
			} else {
				BT_ERR("%s event block is too short", data->hdev->name);
				return -EILSEQ;
			}
			break;

		case HCI_ACLDATA_PKT:
			if (len >= HCI_ACL_HDR_SIZE) {
				struct hci_acl_hdr *hdr = (struct hci_acl_hdr *) buf;
				pkt_len = HCI_ACL_HDR_SIZE + __le16_to_cpu(hdr->dlen);
			} else {
				BT_ERR("%s data block is too short", data->hdev->name);
				return -EILSEQ;
			}
			break;

		case HCI_SCODATA_PKT:
			if (len >= HCI_SCO_HDR_SIZE) {
				struct hci_sco_hdr *hdr = (struct hci_sco_hdr *) buf;
				pkt_len = HCI_SCO_HDR_SIZE + hdr->dlen;
			} else {
				BT_ERR("%s audio block is too short", data->hdev->name);
				return -EILSEQ;
			}
			break;
		}

		skb = bt_skb_alloc(pkt_len, GFP_ATOMIC);
		if (!skb) {
			BT_ERR("%s no memory for the packet", data->hdev->name);
			return -ENOMEM;
		}

		skb->dev = (void *) data->hdev;
		bt_cb(skb)->pkt_type = pkt_type;

		data->reassembly = skb;
	} else {
		if (!data->reassembly) {
			BT_ERR("%s unexpected continuation block", data->hdev->name);
			return -EIO;
		}
	}

	if (len > 0)
		memcpy(skb_put(data->reassembly, len), buf, len);

	if (hdr & 0x08) {
		hci_recv_frame(data->reassembly);
		data->reassembly = NULL;
	}

	return 0;
}

static void bfusb_rx_complete(struct urb *urb)
{
	struct sk_buff *skb = (struct sk_buff *) urb->context;
	struct bfusb_data *data = (struct bfusb_data *) skb->dev;
	unsigned char *buf = urb->transfer_buffer;
	int count = urb->actual_length;
	int err, hdr, len;

	BT_DBG("bfusb %p urb %p skb %p len %d", bfusb, urb, skb, skb->len);

	read_lock(&data->lock);

	if (!test_bit(HCI_RUNNING, &data->hdev->flags))
		goto unlock;

	if (urb->status || !count)
		goto resubmit;

	data->hdev->stat.byte_rx += count;

	skb_put(skb, count);

	while (count) {
		hdr = buf[0] | (buf[1] << 8);

		if (hdr & 0x4000) {
			len = 0;
			count -= 2;
			buf   += 2;
		} else {
			len = (buf[2] == 0) ? 256 : buf[2];
			count -= 3;
			buf   += 3;
		}

		if (count < len) {
			BT_ERR("%s block extends over URB buffer ranges",
					data->hdev->name);
		}

		if ((hdr & 0xe1) == 0xc1)
			bfusb_recv_block(data, hdr, buf, len);

		count -= len;
		buf   += len;
	}

	skb_unlink(skb, &data->pending_q);
	kfree_skb(skb);

	bfusb_rx_submit(data, urb);