/*
   *
   *  AVM BlueFRITZ! USB driver
   *
   *  Copyright (C) 2003-2006  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/module.h>
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/types.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>
  
  #define VERSION "1.2"
  
  static struct usb_driver bfusb_driver;
  
  static const 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", data, 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);
  		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;
  		}
  
  		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->hdev, 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", data, 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);
  
  	read_unlock(&data->lock);
  
  	return;
  
  resubmit:
  	urb->dev = data->udev;
  
  	err = usb_submit_urb(urb, GFP_ATOMIC);
  	if (err) {
  		BT_ERR("%s bulk resubmit failed urb %p err %d",
  					data->hdev->name, urb, err);
  	}
  
  unlock:
  	read_unlock(&data->lock);
  }
  
  static int bfusb_open(struct hci_dev *hdev)
  {
  	struct bfusb_data *data = hci_get_drvdata(hdev);
  	unsigned long flags;
  	int i, err;
  
  	BT_DBG("hdev %p bfusb %p", hdev, data);
  
  	if (test_and_set_bit(HCI_RUNNING, &hdev->flags))
  		return 0;
  
  	write_lock_irqsave(&data->lock, flags);
  
  	err = bfusb_rx_submit(data, NULL);
  	if (!err) {
  		for (i = 1; i < BFUSB_MAX_BULK_RX; i++)
  			bfusb_rx_submit(data, NULL);
  	} else {
  		clear_bit(HCI_RUNNING, &hdev->flags);
  	}
  
  	write_unlock_irqrestore(&data->lock, flags);
  
  	return err;
  }
  
  static int bfusb_flush(struct hci_dev *hdev)
  {
  	struct bfusb_data *data = hci_get_drvdata(hdev);
  
  	BT_DBG("hdev %p bfusb %p", hdev, data);
  
  	skb_queue_purge(&data->transmit_q);
  
  	return 0;
  }
  
  static int bfusb_close(struct hci_dev *hdev)
  {
  	struct bfusb_data *data = hci_get_drvdata(hdev);
  	unsigned long flags;
  
  	BT_DBG("hdev %p bfusb %p", hdev, data);
  
  	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  		return 0;
  
  	write_lock_irqsave(&data->lock, flags);
  	write_unlock_irqrestore(&data->lock, flags);
  
  	bfusb_unlink_urbs(data);
  	bfusb_flush(hdev);
  
  	return 0;
  }
  
  static int bfusb_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
  {
  	struct bfusb_data *data = hci_get_drvdata(hdev);
  	struct sk_buff *nskb;
  	unsigned char buf[3];
  	int sent = 0, size, count;
  
  	BT_DBG("hdev %p skb %p type %d len %d", hdev, skb, bt_cb(skb)->pkt_type, skb->len);
  
  	if (!test_bit(HCI_RUNNING, &hdev->flags))
  		return -EBUSY;
  
  	switch (bt_cb(skb)->pkt_type) {
  	case HCI_COMMAND_PKT:
  		hdev->stat.cmd_tx++;
  		break;
  	case HCI_ACLDATA_PKT:
  		hdev->stat.acl_tx++;
  		break;
  	case HCI_SCODATA_PKT:
  		hdev->stat.sco_tx++;
  		break;
  	};
  
  	/* Prepend skb with frame type */
  	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
  
  	count = skb->len;
  
  	/* Max HCI frame size seems to be 1511 + 1 */
  	nskb = bt_skb_alloc(count + 32, GFP_ATOMIC);
  	if (!nskb) {
  		BT_ERR("Can't allocate memory for new packet");
  		return -ENOMEM;
  	}
  
  	nskb->dev = (void *) data;
  
  	while (count) {
  		size = min_t(uint, count, BFUSB_MAX_BLOCK_SIZE);
  
  		buf[0] = 0xc1 | ((sent == 0) ? 0x04 : 0) | ((count == size) ? 0x08 : 0);
  		buf[1] = 0x00;
  		buf[2] = (size == BFUSB_MAX_BLOCK_SIZE) ? 0 : size;
  
  		memcpy(skb_put(nskb, 3), buf, 3);
  		skb_copy_from_linear_data_offset(skb, sent, skb_put(nskb, size), size);
  
  		sent  += size;
  		count -= size;
  	}
  
  	/* Don't send frame with multiple size of bulk max packet */
  	if ((nskb->len % data->bulk_pkt_size) == 0) {
  		buf[0] = 0xdd;
  		buf[1] = 0x00;
  		memcpy(skb_put(nskb, 2), buf, 2);
  	}
  
  	read_lock(&data->lock);
  
  	skb_queue_tail(&data->transmit_q, nskb);
  	bfusb_tx_wakeup(data);
  
  	read_unlock(&data->lock);
  
  	kfree_skb(skb);
  
  	return 0;
  }
  
  static int bfusb_load_firmware(struct bfusb_data *data,
  			       const unsigned char *firmware, int count)
  {
  	unsigned char *buf;
  	int err, pipe, len, size, sent = 0;
  
  	BT_DBG("bfusb %p udev %p", data, data->udev);
  
  	BT_INFO("BlueFRITZ! USB loading firmware");
  
  	buf = kmalloc(BFUSB_MAX_BLOCK_SIZE + 3, GFP_KERNEL);
  	if (!buf) {
  		BT_ERR("Can't allocate memory chunk for firmware");
  		return -ENOMEM;
  	}
  
  	pipe = usb_sndctrlpipe(data->udev, 0);
  
  	if (usb_control_msg(data->udev, pipe, USB_REQ_SET_CONFIGURATION,
  				0, 1, 0, NULL, 0, USB_CTRL_SET_TIMEOUT) < 0) {
  		BT_ERR("Can't change to loading configuration");
  		kfree(buf);
  		return -EBUSY;
  	}
  
  	data->udev->toggle[0] = data->udev->toggle[1] = 0;
  
  	pipe = usb_sndbulkpipe(data->udev, data->bulk_out_ep);
  
  	while (count) {
  		size = min_t(uint, count, BFUSB_MAX_BLOCK_SIZE + 3);
  
  		memcpy(buf, firmware + sent, size);
  
  		err = usb_bulk_msg(data->udev, pipe, buf, size,
  					&len, BFUSB_BLOCK_TIMEOUT);
  
  		if (err || (len != size)) {
  			BT_ERR("Error in firmware loading");
  			goto error;
  		}
  
  		sent  += size;
  		count -= size;
  	}
  
  	err = usb_bulk_msg(data->udev, pipe, NULL, 0,
  					&len, BFUSB_BLOCK_TIMEOUT);
  	if (err < 0) {
  		BT_ERR("Error in null packet request");
  		goto error;
  	}
  
  	pipe = usb_sndctrlpipe(data->udev, 0);
  
  	err = usb_control_msg(data->udev, pipe, USB_REQ_SET_CONFIGURATION,
  				0, 2, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
  	if (err < 0) {
  		BT_ERR("Can't change to running configuration");
  		goto error;
  	}
  
  	data->udev->toggle[0] = data->udev->toggle[1] = 0;
  
  	BT_INFO("BlueFRITZ! USB device ready");
  
  	kfree(buf);
  	return 0;
  
  error:
  	kfree(buf);
  
  	pipe = usb_sndctrlpipe(data->udev, 0);
  
  	usb_control_msg(data->udev, pipe, USB_REQ_SET_CONFIGURATION,
  				0, 0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
  
  	return err;
  }
  
  static int bfusb_probe(struct usb_interface *intf, const struct usb_device_id *id)
  {
  	const struct firmware *firmware;
  	struct usb_device *udev = interface_to_usbdev(intf);
  	struct usb_host_endpoint *bulk_out_ep;
  	struct usb_host_endpoint *bulk_in_ep;
  	struct hci_dev *hdev;
  	struct bfusb_data *data;
  
  	BT_DBG("intf %p id %p", intf, id);
  
  	/* Check number of endpoints */
  	if (intf->cur_altsetting->desc.bNumEndpoints < 2)
  		return -EIO;
  
  	bulk_out_ep = &intf->cur_altsetting->endpoint[0];
  	bulk_in_ep  = &intf->cur_altsetting->endpoint[1];
  
  	if (!bulk_out_ep || !bulk_in_ep) {
  		BT_ERR("Bulk endpoints not found");
  		goto done;
  	}
  
  	/* Initialize control structure and load firmware */
  	data = devm_kzalloc(&intf->dev, sizeof(struct bfusb_data), GFP_KERNEL);
  	if (!data) {
  		BT_ERR("Can't allocate memory for control structure");
  		goto done;
  	}
  
  	data->udev = udev;
  	data->bulk_in_ep    = bulk_in_ep->desc.bEndpointAddress;
  	data->bulk_out_ep   = bulk_out_ep->desc.bEndpointAddress;
  	data->bulk_pkt_size = le16_to_cpu(bulk_out_ep->desc.wMaxPacketSize);
  
  	rwlock_init(&data->lock);
  
  	data->reassembly = NULL;
  
  	skb_queue_head_init(&data->transmit_q);
  	skb_queue_head_init(&data->pending_q);
  	skb_queue_head_init(&data->completed_q);
  
  	if (request_firmware(&firmware, "bfubase.frm", &udev->dev) < 0) {
  		BT_ERR("Firmware request failed");
  		goto done;
  	}
  
  	BT_DBG("firmware data %p size %zu", firmware->data, firmware->size);
  
  	if (bfusb_load_firmware(data, firmware->data, firmware->size) < 0) {
  		BT_ERR("Firmware loading failed");
  		goto release;
  	}
  
  	release_firmware(firmware);
  
  	/* Initialize and register HCI device */
  	hdev = hci_alloc_dev();
  	if (!hdev) {
  		BT_ERR("Can't allocate HCI device");
  		goto done;
  	}
  
  	data->hdev = hdev;
  
  	hdev->bus = HCI_USB;
  	hci_set_drvdata(hdev, data);
  	SET_HCIDEV_DEV(hdev, &intf->dev);
  
  	hdev->open  = bfusb_open;
  	hdev->close = bfusb_close;
  	hdev->flush = bfusb_flush;
  	hdev->send  = bfusb_send_frame;
  
  	if (hci_register_dev(hdev) < 0) {
  		BT_ERR("Can't register HCI device");
  		hci_free_dev(hdev);
  		goto done;
  	}
  
  	usb_set_intfdata(intf, data);
  
  	return 0;
  
  release:
  	release_firmware(firmware);
  
  done:
  	return -EIO;
  }
  
  static void bfusb_disconnect(struct usb_interface *intf)
  {
  	struct bfusb_data *data = usb_get_intfdata(intf);
  	struct hci_dev *hdev = data->hdev;
  
  	BT_DBG("intf %p", intf);
  
  	if (!hdev)
  		return;
  
  	usb_set_intfdata(intf, NULL);
  
  	bfusb_close(hdev);
  
  	hci_unregister_dev(hdev);
  	hci_free_dev(hdev);
  }
  
  static struct usb_driver bfusb_driver = {
  	.name		= "bfusb",
  	.probe		= bfusb_probe,
  	.disconnect	= bfusb_disconnect,
  	.id_table	= bfusb_table,
  	.disable_hub_initiated_lpm = 1,
  };
  
  module_usb_driver(bfusb_driver);
  
  MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
  MODULE_DESCRIPTION("BlueFRITZ! USB driver ver " VERSION);
  MODULE_VERSION(VERSION);
  MODULE_LICENSE("GPL");
  MODULE_FIRMWARE("bfubase.frm");