/*
   *
   *  Digianswer Bluetooth USB driver
   *
   *  Copyright (C) 2004-2007  Marcel Holtmann <marcel@holtmann.org>
   *
   *
   *  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/module.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/usb.h>
  
  #include <net/bluetooth/bluetooth.h>
  #include <net/bluetooth/hci_core.h>
  
  #define VERSION "0.10"
  
  static const struct usb_device_id bpa10x_table[] = {
  	/* Tektronix BPA 100/105 (Digianswer) */
  	{ USB_DEVICE(0x08fd, 0x0002) },
  
  	{ }	/* Terminating entry */
  };
  
  MODULE_DEVICE_TABLE(usb, bpa10x_table);
  
  struct bpa10x_data {
  	struct hci_dev    *hdev;
  	struct usb_device *udev;
  
  	struct usb_anchor tx_anchor;
  	struct usb_anchor rx_anchor;
  
  	struct sk_buff *rx_skb[2];
  };
  
  #define HCI_VENDOR_HDR_SIZE 5
  
  struct hci_vendor_hdr {
  	__u8    type;
  	__le16  snum;
  	__le16  dlen;
  } __packed;
  
  static int bpa10x_recv(struct hci_dev *hdev, int queue, void *buf, int count)
  {
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  
  	BT_DBG("%s queue %d buffer %p count %d", hdev->name,
  							queue, buf, count);
  
  	if (queue < 0 || queue > 1)
  		return -EILSEQ;
  
  	hdev->stat.byte_rx += count;
  
  	while (count) {
  		struct sk_buff *skb = data->rx_skb[queue];
  		struct { __u8 type; int expect; } *scb;
  		int type, len = 0;
  
  		if (!skb) {
  			/* Start of the frame */
  
  			type = *((__u8 *) buf);
  			count--; buf++;
  
  			switch (type) {
  			case HCI_EVENT_PKT:
  				if (count >= HCI_EVENT_HDR_SIZE) {
  					struct hci_event_hdr *h = buf;
  					len = HCI_EVENT_HDR_SIZE + h->plen;
  				} else
  					return -EILSEQ;
  				break;
  
  			case HCI_ACLDATA_PKT:
  				if (count >= HCI_ACL_HDR_SIZE) {
  					struct hci_acl_hdr *h = buf;
  					len = HCI_ACL_HDR_SIZE +
  							__le16_to_cpu(h->dlen);
  				} else
  					return -EILSEQ;
  				break;
  
  			case HCI_SCODATA_PKT:
  				if (count >= HCI_SCO_HDR_SIZE) {
  					struct hci_sco_hdr *h = buf;
  					len = HCI_SCO_HDR_SIZE + h->dlen;
  				} else
  					return -EILSEQ;
  				break;
  
  			case HCI_VENDOR_PKT:
  				if (count >= HCI_VENDOR_HDR_SIZE) {
  					struct hci_vendor_hdr *h = buf;
  					len = HCI_VENDOR_HDR_SIZE +
  							__le16_to_cpu(h->dlen);
  				} else
  					return -EILSEQ;
  				break;
  			}
  
  			skb = bt_skb_alloc(len, GFP_ATOMIC);
  			if (!skb) {
  				BT_ERR("%s no memory for packet", hdev->name);
  				return -ENOMEM;
  			}
  
  			data->rx_skb[queue] = skb;
  
  			scb = (void *) skb->cb;
  			scb->type = type;
  			scb->expect = len;
  		} else {
  			/* Continuation */
  
  			scb = (void *) skb->cb;
  			len = scb->expect;
  		}
  
  		len = min(len, count);
  
  		memcpy(skb_put(skb, len), buf, len);
  
  		scb->expect -= len;
  
  		if (scb->expect == 0) {
  			/* Complete frame */
  
  			data->rx_skb[queue] = NULL;
  
  			bt_cb(skb)->pkt_type = scb->type;
  			hci_recv_frame(hdev, skb);
  		}
  
  		count -= len; buf += len;
  	}
  
  	return 0;
  }
  
  static void bpa10x_tx_complete(struct urb *urb)
  {
  	struct sk_buff *skb = urb->context;
  	struct hci_dev *hdev = (struct hci_dev *) skb->dev;
  
  	BT_DBG("%s urb %p status %d count %d", hdev->name,
  					urb, urb->status, urb->actual_length);
  
  	if (!test_bit(HCI_RUNNING, &hdev->flags))
  		goto done;
  
  	if (!urb->status)
  		hdev->stat.byte_tx += urb->transfer_buffer_length;
  	else
  		hdev->stat.err_tx++;
  
  done:
  	kfree(urb->setup_packet);
  
  	kfree_skb(skb);
  }
  
  static void bpa10x_rx_complete(struct urb *urb)
  {
  	struct hci_dev *hdev = urb->context;
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  	int err;
  
  	BT_DBG("%s urb %p status %d count %d", hdev->name,
  					urb, urb->status, urb->actual_length);
  
  	if (!test_bit(HCI_RUNNING, &hdev->flags))
  		return;
  
  	if (urb->status == 0) {
  		if (bpa10x_recv(hdev, usb_pipebulk(urb->pipe),
  						urb->transfer_buffer,
  						urb->actual_length) < 0) {
  			BT_ERR("%s corrupted event packet", hdev->name);
  			hdev->stat.err_rx++;
  		}
  	}
  
  	usb_anchor_urb(urb, &data->rx_anchor);
  
  	err = usb_submit_urb(urb, GFP_ATOMIC);
  	if (err < 0) {
  		BT_ERR("%s urb %p failed to resubmit (%d)",
  						hdev->name, urb, -err);
  		usb_unanchor_urb(urb);
  	}
  }
  
  static inline int bpa10x_submit_intr_urb(struct hci_dev *hdev)
  {
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  	struct urb *urb;
  	unsigned char *buf;
  	unsigned int pipe;
  	int err, size = 16;
  
  	BT_DBG("%s", hdev->name);
  
  	urb = usb_alloc_urb(0, GFP_KERNEL);
  	if (!urb)
  		return -ENOMEM;
  
  	buf = kmalloc(size, GFP_KERNEL);
  	if (!buf) {
  		usb_free_urb(urb);
  		return -ENOMEM;
  	}
  
  	pipe = usb_rcvintpipe(data->udev, 0x81);
  
  	usb_fill_int_urb(urb, data->udev, pipe, buf, size,
  						bpa10x_rx_complete, hdev, 1);
  
  	urb->transfer_flags |= URB_FREE_BUFFER;
  
  	usb_anchor_urb(urb, &data->rx_anchor);
  
  	err = usb_submit_urb(urb, GFP_KERNEL);
  	if (err < 0) {
  		BT_ERR("%s urb %p submission failed (%d)",
  						hdev->name, urb, -err);
  		usb_unanchor_urb(urb);
  	}
  
  	usb_free_urb(urb);
  
  	return err;
  }
  
  static inline int bpa10x_submit_bulk_urb(struct hci_dev *hdev)
  {
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  	struct urb *urb;
  	unsigned char *buf;
  	unsigned int pipe;
  	int err, size = 64;
  
  	BT_DBG("%s", hdev->name);
  
  	urb = usb_alloc_urb(0, GFP_KERNEL);
  	if (!urb)
  		return -ENOMEM;
  
  	buf = kmalloc(size, GFP_KERNEL);
  	if (!buf) {
  		usb_free_urb(urb);
  		return -ENOMEM;
  	}
  
  	pipe = usb_rcvbulkpipe(data->udev, 0x82);
  
  	usb_fill_bulk_urb(urb, data->udev, pipe,
  					buf, size, bpa10x_rx_complete, hdev);
  
  	urb->transfer_flags |= URB_FREE_BUFFER;
  
  	usb_anchor_urb(urb, &data->rx_anchor);
  
  	err = usb_submit_urb(urb, GFP_KERNEL);
  	if (err < 0) {
  		BT_ERR("%s urb %p submission failed (%d)",
  						hdev->name, urb, -err);
  		usb_unanchor_urb(urb);
  	}
  
  	usb_free_urb(urb);
  
  	return err;
  }
  
  static int bpa10x_open(struct hci_dev *hdev)
  {
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  	int err;
  
  	BT_DBG("%s", hdev->name);
  
  	if (test_and_set_bit(HCI_RUNNING, &hdev->flags))
  		return 0;
  
  	err = bpa10x_submit_intr_urb(hdev);
  	if (err < 0)
  		goto error;
  
  	err = bpa10x_submit_bulk_urb(hdev);
  	if (err < 0)
  		goto error;
  
  	return 0;
  
  error:
  	usb_kill_anchored_urbs(&data->rx_anchor);
  
  	clear_bit(HCI_RUNNING, &hdev->flags);
  
  	return err;
  }
  
  static int bpa10x_close(struct hci_dev *hdev)
  {
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  
  	BT_DBG("%s", hdev->name);
  
  	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  		return 0;
  
  	usb_kill_anchored_urbs(&data->rx_anchor);
  
  	return 0;
  }
  
  static int bpa10x_flush(struct hci_dev *hdev)
  {
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  
  	BT_DBG("%s", hdev->name);
  
  	usb_kill_anchored_urbs(&data->tx_anchor);
  
  	return 0;
  }
  
  static int bpa10x_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
  {
  	struct bpa10x_data *data = hci_get_drvdata(hdev);
  	struct usb_ctrlrequest *dr;
  	struct urb *urb;
  	unsigned int pipe;
  	int err;
  
  	BT_DBG("%s", hdev->name);
  
  	if (!test_bit(HCI_RUNNING, &hdev->flags))
  		return -EBUSY;
  
  	skb->dev = (void *) hdev;
  
  	urb = usb_alloc_urb(0, GFP_ATOMIC);
  	if (!urb)
  		return -ENOMEM;
  
  	/* Prepend skb with frame type */
  	*skb_push(skb, 1) = bt_cb(skb)->pkt_type;
  
  	switch (bt_cb(skb)->pkt_type) {
  	case HCI_COMMAND_PKT:
  		dr = kmalloc(sizeof(*dr), GFP_ATOMIC);
  		if (!dr) {
  			usb_free_urb(urb);
  			return -ENOMEM;
  		}
  
  		dr->bRequestType = USB_TYPE_VENDOR;
  		dr->bRequest     = 0;
  		dr->wIndex       = 0;
  		dr->wValue       = 0;
  		dr->wLength      = __cpu_to_le16(skb->len);
  
  		pipe = usb_sndctrlpipe(data->udev, 0x00);
  
  		usb_fill_control_urb(urb, data->udev, pipe, (void *) dr,
  				skb->data, skb->len, bpa10x_tx_complete, skb);
  
  		hdev->stat.cmd_tx++;
  		break;
  
  	case HCI_ACLDATA_PKT:
  		pipe = usb_sndbulkpipe(data->udev, 0x02);
  
  		usb_fill_bulk_urb(urb, data->udev, pipe,
  				skb->data, skb->len, bpa10x_tx_complete, skb);
  
  		hdev->stat.acl_tx++;
  		break;
  
  	case HCI_SCODATA_PKT:
  		pipe = usb_sndbulkpipe(data->udev, 0x02);
  
  		usb_fill_bulk_urb(urb, data->udev, pipe,
  				skb->data, skb->len, bpa10x_tx_complete, skb);
  
  		hdev->stat.sco_tx++;
  		break;
  
  	default:
  		usb_free_urb(urb);
  		return -EILSEQ;
  	}
  
  	usb_anchor_urb(urb, &data->tx_anchor);
  
  	err = usb_submit_urb(urb, GFP_ATOMIC);
  	if (err < 0) {
  		BT_ERR("%s urb %p submission failed", hdev->name, urb);
  		kfree(urb->setup_packet);
  		usb_unanchor_urb(urb);
  	}
  
  	usb_free_urb(urb);
  
  	return 0;
  }
  
  static int bpa10x_probe(struct usb_interface *intf, const struct usb_device_id *id)
  {
  	struct bpa10x_data *data;
  	struct hci_dev *hdev;
  	int err;
  
  	BT_DBG("intf %p id %p", intf, id);
  
  	if (intf->cur_altsetting->desc.bInterfaceNumber != 0)
  		return -ENODEV;
  
  	data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	data->udev = interface_to_usbdev(intf);
  
  	init_usb_anchor(&data->tx_anchor);
  	init_usb_anchor(&data->rx_anchor);
  
  	hdev = hci_alloc_dev();
  	if (!hdev)
  		return -ENOMEM;
  
  	hdev->bus = HCI_USB;
  	hci_set_drvdata(hdev, data);
  
  	data->hdev = hdev;
  
  	SET_HCIDEV_DEV(hdev, &intf->dev);
  
  	hdev->open     = bpa10x_open;
  	hdev->close    = bpa10x_close;
  	hdev->flush    = bpa10x_flush;
  	hdev->send     = bpa10x_send_frame;
  
  	set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
  
  	err = hci_register_dev(hdev);
  	if (err < 0) {
  		hci_free_dev(hdev);
  		return err;
  	}
  
  	usb_set_intfdata(intf, data);
  
  	return 0;
  }
  
  static void bpa10x_disconnect(struct usb_interface *intf)
  {
  	struct bpa10x_data *data = usb_get_intfdata(intf);
  
  	BT_DBG("intf %p", intf);
  
  	if (!data)
  		return;
  
  	usb_set_intfdata(intf, NULL);
  
  	hci_unregister_dev(data->hdev);
  
  	hci_free_dev(data->hdev);
  	kfree_skb(data->rx_skb[0]);
  	kfree_skb(data->rx_skb[1]);
  }
  
  static struct usb_driver bpa10x_driver = {
  	.name		= "bpa10x",
  	.probe		= bpa10x_probe,
  	.disconnect	= bpa10x_disconnect,
  	.id_table	= bpa10x_table,
  	.disable_hub_initiated_lpm = 1,
  };
  
  module_usb_driver(bpa10x_driver);
  
  MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
  MODULE_DESCRIPTION("Digianswer Bluetooth USB driver ver " VERSION);
  MODULE_VERSION(VERSION);
  MODULE_LICENSE("GPL");