text: /*
   * ipheth.c - Apple iPhone USB Ethernet driver
   *
   * Copyright (c) 2009 Diego Giagio <diego@giagio.com>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of GIAGIO.COM nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * Alternatively, provided that this notice is retained in full, this
   * software may be distributed under the terms of the GNU General
   * Public License ("GPL") version 2, in which case the provisions of the
   * GPL apply INSTEAD OF those given above.
   *
   * The provided data structures and external interfaces from this code
   * are not restricted to be used by modules with a GPL compatible license.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
   * DAMAGE.
   *
   *
   * Attention: iPhone device must be paired, otherwise it won't respond to our
   * driver. For more info: http://giagio.com/wiki/moin.cgi/iPhoneEthernetDriver
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/ethtool.h>
  #include <linux/usb.h>
  #include <linux/workqueue.h>
  
  #define USB_VENDOR_APPLE        0x05ac
  #define USB_PRODUCT_IPHONE      0x1290
  #define USB_PRODUCT_IPHONE_3G   0x1292
  #define USB_PRODUCT_IPHONE_3GS  0x1294
  #define USB_PRODUCT_IPHONE_4	0x1297
  #define USB_PRODUCT_IPAD 0x129a
  #define USB_PRODUCT_IPAD_2	0x12a2
  #define USB_PRODUCT_IPAD_3	0x12a6
  #define USB_PRODUCT_IPAD_MINI    0x12ab
  #define USB_PRODUCT_IPHONE_4_VZW 0x129c
  #define USB_PRODUCT_IPHONE_4S	0x12a0
  #define USB_PRODUCT_IPHONE_5	0x12a8
  
  #define IPHETH_USBINTF_CLASS    255
  #define IPHETH_USBINTF_SUBCLASS 253
  #define IPHETH_USBINTF_PROTO    1
  
  #define IPHETH_BUF_SIZE         1516
  #define IPHETH_IP_ALIGN		2	/* padding at front of URB */
  #define IPHETH_TX_TIMEOUT       (5 * HZ)
  
  #define IPHETH_INTFNUM          2
  #define IPHETH_ALT_INTFNUM      1
  
  #define IPHETH_CTRL_ENDP        0x00
  #define IPHETH_CTRL_BUF_SIZE    0x40
  #define IPHETH_CTRL_TIMEOUT     (5 * HZ)
  
  #define IPHETH_CMD_GET_MACADDR   0x00
  #define IPHETH_CMD_CARRIER_CHECK 0x45
  
  #define IPHETH_CARRIER_CHECK_TIMEOUT round_jiffies_relative(1 * HZ)
  #define IPHETH_CARRIER_ON       0x04
  
  static struct usb_device_id ipheth_table[] = {
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_3G,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_3GS,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPAD,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPAD_2,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPAD_3,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPAD_MINI,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4_VZW,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4S,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(
  		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_5,
  		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
  		IPHETH_USBINTF_PROTO) },
  	{ }
  };
  MODULE_DEVICE_TABLE(usb, ipheth_table);
  
  struct ipheth_device {
  	struct usb_device *udev;
  	struct usb_interface *intf;
  	struct net_device *net;
  	struct sk_buff *tx_skb;
  	struct urb *tx_urb;
  	struct urb *rx_urb;
  	unsigned char *tx_buf;
  	unsigned char *rx_buf;
  	unsigned char *ctrl_buf;
  	u8 bulk_in;
  	u8 bulk_out;
  	struct delayed_work carrier_work;
  };
  
  static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags);
  
  static int ipheth_alloc_urbs(struct ipheth_device *iphone)
  {
  	struct urb *tx_urb = NULL;
  	struct urb *rx_urb = NULL;
  	u8 *tx_buf = NULL;
  	u8 *rx_buf = NULL;
  
  	tx_urb = usb_alloc_urb(0, GFP_KERNEL);
  	if (tx_urb == NULL)
  		goto error_nomem;
  
  	rx_urb = usb_alloc_urb(0, GFP_KERNEL);
  	if (rx_urb == NULL)
  		goto free_tx_urb;
  
  	tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
  				    GFP_KERNEL, &tx_urb->transfer_dma);
  	if (tx_buf == NULL)
  		goto free_rx_urb;
  
  	rx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
  				    GFP_KERNEL, &rx_urb->transfer_dma);
  	if (rx_buf == NULL)
  		goto free_tx_buf;
  
  
  	iphone->tx_urb = tx_urb;
  	iphone->rx_urb = rx_urb;
  	iphone->tx_buf = tx_buf;
  	iphone->rx_buf = rx_buf;
  	return 0;
  
  free_tx_buf:
  	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, tx_buf,
  			  tx_urb->transfer_dma);
  free_rx_urb:
  	usb_free_urb(rx_urb);
  free_tx_urb:
  	usb_free_urb(tx_urb);
  error_nomem:
  	return -ENOMEM;
  }
  
  static void ipheth_free_urbs(struct ipheth_device *iphone)
  {
  	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->rx_buf,
  			  iphone->rx_urb->transfer_dma);
  	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->tx_buf,
  			  iphone->tx_urb->transfer_dma);
  	usb_free_urb(iphone->rx_urb);
  	usb_free_urb(iphone->tx_urb);
  }
  
  static void ipheth_kill_urbs(struct ipheth_device *dev)
  {
  	usb_kill_urb(dev->tx_urb);
  	usb_kill_urb(dev->rx_urb);
  }
  
  static void ipheth_rcvbulk_callback(struct urb *urb)
  {
  	struct ipheth_device *dev;
  	struct sk_buff *skb;
  	int status;
  	char *buf;
  	int len;
  
  	dev = urb->context;
  	if (dev == NULL)
  		return;
  
  	status = urb->status;
  	switch (status) {
  	case -ENOENT:
  	case -ECONNRESET:
  	case -ESHUTDOWN:
  		return;
  	case 0:
  		break;
  	default:
  		dev_err(&dev->intf->dev, "%s: urb status: %d\n",
  			__func__, status);
  		return;
  	}
  
  	if (urb->actual_length <= IPHETH_IP_ALIGN) {
  		dev->net->stats.rx_length_errors++;
  		return;
  	}
  	len = urb->actual_length - IPHETH_IP_ALIGN;
  	buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
  
  	skb = dev_alloc_skb(len);
  	if (!skb) {
  		dev_err(&dev->intf->dev, "%s: dev_alloc_skb: -ENOMEM\n",
  			__func__);
  		dev->net->stats.rx_dropped++;
  		return;
  	}
  
  	skb_put_data(skb, buf, len);
  	skb->dev = dev->net;
  	skb->protocol = eth_type_trans(skb, dev->net);
  
  	dev->net->stats.rx_packets++;
  	dev->net->stats.rx_bytes += len;
  
  	netif_rx(skb);
  	ipheth_rx_submit(dev, GFP_ATOMIC);
  }
  
  static void ipheth_sndbulk_callback(struct urb *urb)
  {
  	struct ipheth_device *dev;
  	int status = urb->status;
  
  	dev = urb->context;
  	if (dev == NULL)
  		return;
  
  	if (status != 0 &&
  	    status != -ENOENT &&
  	    status != -ECONNRESET &&
  	    status != -ESHUTDOWN)
  		dev_err(&dev->intf->dev, "%s: urb status: %d\n",
  		__func__, status);
  
  	dev_kfree_skb_irq(dev->tx_skb);
  	netif_wake_queue(dev->net);
  }
  
  static int ipheth_carrier_set(struct ipheth_device *dev)
  {
  	struct usb_device *udev = dev->udev;
  	int retval;
  
  	retval = usb_control_msg(udev,
  			usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
  			IPHETH_CMD_CARRIER_CHECK, /* request */
  			0xc0, /* request type */
  			0x00, /* value */
  			0x02, /* index */
  			dev->ctrl_buf, IPHETH_CTRL_BUF_SIZE,
  			IPHETH_CTRL_TIMEOUT);
  	if (retval < 0) {
  		dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
  			__func__, retval);
  		return retval;
  	}
  
  	if (dev->ctrl_buf[0] == IPHETH_CARRIER_ON)
  		netif_carrier_on(dev->net);
  	else
  		netif_carrier_off(dev->net);
  
  	return 0;
  }
  
  static void ipheth_carrier_check_work(struct work_struct *work)
  {
  	struct ipheth_device *dev = container_of(work, struct ipheth_device,
  						 carrier_work.work);
  
  	ipheth_carrier_set(dev);
  	schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
  }
  
  static int ipheth_get_macaddr(struct ipheth_device *dev)
  {
  	struct usb_device *udev = dev->udev;
  	struct net_device *net = dev->net;
  	int retval;
  
  	retval = usb_control_msg(udev,
  				 usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
  				 IPHETH_CMD_GET_MACADDR, /* request */
  				 0xc0, /* request type */
  				 0x00, /* value */
  				 0x02, /* index */
  				 dev->ctrl_buf,
  				 IPHETH_CTRL_BUF_SIZE,
  				 IPHETH_CTRL_TIMEOUT);
  	if (retval < 0) {
  		dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
  			__func__, retval);
  	} else if (retval < ETH_ALEN) {
  		dev_err(&dev->intf->dev,
  			"%s: usb_control_msg: short packet: %d bytes\n",
  			__func__, retval);
  		retval = -EINVAL;
  	} else {
  		memcpy(net->dev_addr, dev->ctrl_buf, ETH_ALEN);
  		retval = 0;
  	}
  
  	return retval;
  }
  
  static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags)
  {
  	struct usb_device *udev = dev->udev;
  	int retval;
  
  	usb_fill_bulk_urb(dev->rx_urb, udev,
  			  usb_rcvbulkpipe(udev, dev->bulk_in),
  			  dev->rx_buf, IPHETH_BUF_SIZE,
  			  ipheth_rcvbulk_callback,
  			  dev);
  	dev->rx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
  
  	retval = usb_submit_urb(dev->rx_urb, mem_flags);
  	if (retval)
  		dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
  			__func__, retval);
  	return retval;
  }
  
  static int ipheth_open(struct net_device *net)
  {
  	struct ipheth_device *dev = netdev_priv(net);
  	struct usb_device *udev = dev->udev;
  	int retval = 0;
  
  	usb_set_interface(udev, IPHETH_INTFNUM, IPHETH_ALT_INTFNUM);
  
  	retval = ipheth_carrier_set(dev);
  	if (retval)
  		return retval;
  
  	retval = ipheth_rx_submit(dev, GFP_KERNEL);
  	if (retval)
  		return retval;
  
  	schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
  	netif_start_queue(net);
  	return retval;
  }
  
  static int ipheth_close(struct net_device *net)
  {
  	struct ipheth_device *dev = netdev_priv(net);
  
  	cancel_delayed_work_sync(&dev->carrier_work);
  	netif_stop_queue(net);
  	return 0;
  }
  
  static int ipheth_tx(struct sk_buff *skb, struct net_device *net)
  {
  	struct ipheth_device *dev = netdev_priv(net);
  	struct usb_device *udev = dev->udev;
  	int retval;
  
  	/* Paranoid */
  	if (skb->len > IPHETH_BUF_SIZE) {
  		WARN(1, "%s: skb too large: %d bytes\n", __func__, skb->len);
  		dev->net->stats.tx_dropped++;
  		dev_kfree_skb_irq(skb);
  		return NETDEV_TX_OK;
  	}
  
  	memcpy(dev->tx_buf, skb->data, skb->len);
  	if (skb->len < IPHETH_BUF_SIZE)
  		memset(dev->tx_buf + skb->len, 0, IPHETH_BUF_SIZE - skb->len);
  
  	usb_fill_bulk_urb(dev->tx_urb, udev,
  			  usb_sndbulkpipe(udev, dev->bulk_out),
  			  dev->tx_buf, IPHETH_BUF_SIZE,
  			  ipheth_sndbulk_callback,
  			  dev);
  	dev->tx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
  
  	retval = usb_submit_urb(dev->tx_urb, GFP_ATOMIC);
  	if (retval) {
  		dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
  			__func__, retval);
  		dev->net->stats.tx_errors++;
  		dev_kfree_skb_irq(skb);
  	} else {
  		dev->tx_skb = skb;
  
  		dev->net->stats.tx_packets++;
  		dev->net->stats.tx_bytes += skb->len;
  		netif_stop_queue(net);
  	}
  
  	return NETDEV_TX_OK;
  }
  
  static void ipheth_tx_timeout(struct net_device *net)
  {
  	struct ipheth_device *dev = netdev_priv(net);
  
  	dev_err(&dev->intf->dev, "%s: TX timeout\n", __func__);
  	dev->net->stats.tx_errors++;
  	usb_unlink_urb(dev->tx_urb);
  }
  
  static u32 ipheth_ethtool_op_get_link(struct net_device *net)
  {
  	struct ipheth_device *dev = netdev_priv(net);
  	return netif_carrier_ok(dev->net);
  }
  
  static const struct ethtool_ops ops = {
  	.get_link = ipheth_ethtool_op_get_link
  };
  
  static const struct net_device_ops ipheth_netdev_ops = {
  	.ndo_open = ipheth_open,
  	.ndo_stop = ipheth_close,
  	.ndo_start_xmit = ipheth_tx,
  	.ndo_tx_timeout = ipheth_tx_timeout,
  };
  
  static int ipheth_probe(struct usb_interface *intf,
  			const struct usb_device_id *id)
  {
  	struct usb_device *udev = interface_to_usbdev(intf);
  	struct usb_host_interface *hintf;
  	struct usb_endpoint_descriptor *endp;
  	struct ipheth_device *dev;
  	struct net_device *netdev;
  	int i;
  	int retval;
  
  	netdev = alloc_etherdev(sizeof(struct ipheth_device));
  	if (!netdev)
  		return -ENOMEM;
  
  	netdev->netdev_ops = &ipheth_netdev_ops;
  	netdev->watchdog_timeo = IPHETH_TX_TIMEOUT;
  	strcpy(netdev->name, "eth%d");
  
  	dev = netdev_priv(netdev);
  	dev->udev = udev;
  	dev->net = netdev;
  	dev->intf = intf;
  
  	/* Set up endpoints */
  	hintf = usb_altnum_to_altsetting(intf, IPHETH_ALT_INTFNUM);
  	if (hintf == NULL) {
  		retval = -ENODEV;
  		dev_err(&intf->dev, "Unable to find alternate settings interface\n");
  		goto err_endpoints;
  	}
  
  	for (i = 0; i < hintf->desc.bNumEndpoints; i++) {
  		endp = &hintf->endpoint[i].desc;
  		if (usb_endpoint_is_bulk_in(endp))
  			dev->bulk_in = endp->bEndpointAddress;
  		else if (usb_endpoint_is_bulk_out(endp))
  			dev->bulk_out = endp->bEndpointAddress;
  	}
  	if (!(dev->bulk_in && dev->bulk_out)) {
  		retval = -ENODEV;
  		dev_err(&intf->dev, "Unable to find endpoints\n");
  		goto err_endpoints;
  	}
  
  	dev->ctrl_buf = kmalloc(IPHETH_CTRL_BUF_SIZE, GFP_KERNEL);
  	if (dev->ctrl_buf == NULL) {
  		retval = -ENOMEM;
  		goto err_alloc_ctrl_buf;
  	}
  
  	retval = ipheth_get_macaddr(dev);
  	if (retval)
  		goto err_get_macaddr;
  
  	INIT_DELAYED_WORK(&dev->carrier_work, ipheth_carrier_check_work);
  
  	retval = ipheth_alloc_urbs(dev);
  	if (retval) {
  		dev_err(&intf->dev, "error allocating urbs: %d\n", retval);
  		goto err_alloc_urbs;
  	}
  
  	usb_set_intfdata(intf, dev);
  
  	SET_NETDEV_DEV(netdev, &intf->dev);
  	netdev->ethtool_ops = &ops;
  
  	retval = register_netdev(netdev);
  	if (retval) {
  		dev_err(&intf->dev, "error registering netdev: %d\n", retval);
  		retval = -EIO;
  		goto err_register_netdev;
  	}
  
  	dev_info(&intf->dev, "Apple iPhone USB Ethernet device attached\n");
  	return 0;
  
  err_register_netdev:
  	ipheth_free_urbs(dev);
  err_alloc_urbs:
  err_get_macaddr:
  err_alloc_ctrl_buf:
  	kfree(dev->ctrl_buf);
  err_endpoints:
  	free_netdev(netdev);
  	return retval;
  }
  
  static void ipheth_disconnect(struct usb_interface *intf)
  {
  	struct ipheth_device *dev;
  
  	dev = usb_get_intfdata(intf);
  	if (dev != NULL) {
  		unregister_netdev(dev->net);
  		ipheth_kill_urbs(dev);
  		ipheth_free_urbs(dev);
  		kfree(dev->ctrl_buf);
  		free_netdev(dev->net);
  	}
  	usb_set_intfdata(intf, NULL);
  	dev_info(&intf->dev, "Apple iPhone USB Ethernet now disconnected\n");
  }
  
  static struct usb_driver ipheth_driver = {
  	.name =		"ipheth",
  	.probe =	ipheth_probe,
  	.disconnect =	ipheth_disconnect,
  	.id_table =	ipheth_table,
  	.disable_hub_initiated_lpm = 1,
  };
  
  module_usb_driver(ipheth_driver);
  
  MODULE_AUTHOR("Diego Giagio <diego@giagio.com>");
  MODULE_DESCRIPTION("Apple iPhone USB Ethernet driver");
  MODULE_LICENSE("Dual BSD/GPL");
  