usb driver for intellon int51x1 based PLC like devolo dlan duo

usb driver for intellon int51x1 based PLC like devolo dlan duo
with improvements suggested by the guys of the mailinglist:
- name and prefix with int51x1 (Florian Fainelli)
- use conversion functions cpu_to_le16 / le16_to_cpu (Oliver Neukum)
- use pskb_may_pull instead of skb->len (Ilpo Järvinen)
- better code in tx_fixup (Ilpo Järvinen)
- use gotos for error handling (Ilpo Järvinen)
- better description (Jon Smirl)
Signed-off-by: Peter Holik <peter@holik.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/Kconfig

@@ -345,4 +345,12 @@ config USB_HSO
 	  To compile this driver as a module, choose M here: the
 	  module will be called hso.
 
+config USB_NET_INT51X1
+	tristate "Intellon PLC based usb adapter"
+	depends on USB_USBNET
+	help
+	  Choose this option if you're using a 14Mb USB-based PLC
+	  (Powerline Communications) solution with an Intellon
+	  INT51x1/INT5200 chip, like the "devolo dLan duo".
+
 endmenu

drivers/net/usb/Makefile

@@ -19,4 +19,5 @@ obj-$(CONFIG_USB_NET_CDC_SUBSET)	+= cdc_subset.o
 obj-$(CONFIG_USB_NET_ZAURUS)	+= zaurus.o
 obj-$(CONFIG_USB_NET_MCS7830)	+= mcs7830.o
 obj-$(CONFIG_USB_USBNET)	+= usbnet.o
+obj-$(CONFIG_USB_NET_INT51X1)	+= int51x1.o
 

drivers/net/usb/int51x1.c

+/*
+ * Copyright (c) 2009 Peter Holik
+ *
+ * Intellon usb PLC (Powerline Communications) usb net driver
+ *
+ * http://www.tandel.be/downloads/INT51X1_Datasheet.pdf
+ *
+ * Based on the work of Jan 'RedBully' Seiffert
+ */
+
+/*
+ * 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/ctype.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/usbnet.h>
+
+#define INT51X1_VENDOR_ID	0x09e1
+#define INT51X1_PRODUCT_ID	0x5121
+
+#define INT51X1_HEADER_SIZE	2	/* 2 byte header */
+
+#define PACKET_TYPE_PROMISCUOUS		(1 << 0)
+#define PACKET_TYPE_ALL_MULTICAST	(1 << 1) /* no filter */
+#define PACKET_TYPE_DIRECTED		(1 << 2)
+#define PACKET_TYPE_BROADCAST		(1 << 3)
+#define PACKET_TYPE_MULTICAST		(1 << 4) /* filtered */
+
+#define SET_ETHERNET_PACKET_FILTER	0x43
+
+static int int51x1_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+	int len;
+
+	if (!(pskb_may_pull(skb, INT51X1_HEADER_SIZE))) {
+		deverr(dev, "unexpected tiny rx frame");
+		return 0;
+	}
+
+	len = le16_to_cpu(*(__le16 *)&skb->data[skb->len - 2]);
+
+	skb_trim(skb, len);
+
+	return 1;
+}
+
+static struct sk_buff *int51x1_tx_fixup(struct usbnet *dev,
+		struct sk_buff *skb, gfp_t flags)
+{
+	int pack_len = skb->len;
+	int pack_with_header_len = pack_len + INT51X1_HEADER_SIZE;
+	int headroom = skb_headroom(skb);
+	int tailroom = skb_tailroom(skb);
+	int need_tail = 0;
+	__le16 *len;
+
+	/* if packet and our header is smaler than 64 pad to 64 (+ ZLP) */
+	if ((pack_with_header_len) < dev->maxpacket)
+		need_tail = dev->maxpacket - pack_with_header_len + 1;
+	/*
+	 * usbnet would send a ZLP if packetlength mod urbsize == 0 for us,
+	 * but we need to know ourself, because this would add to the length
+	 * we send down to the device...
+	 */
+	else if (!(pack_with_header_len % dev->maxpacket))
+		need_tail = 1;
+
+	if (!skb_cloned(skb) &&
+			(headroom + tailroom >= need_tail + INT51X1_HEADER_SIZE)) {
+		if (headroom < INT51X1_HEADER_SIZE || tailroom < need_tail) {
+			skb->data = memmove(skb->head + INT51X1_HEADER_SIZE,
+					skb->data, skb->len);
+			skb_set_tail_pointer(skb, skb->len);
+		}
+	} else {
+		struct sk_buff *skb2;
+
+		skb2 = skb_copy_expand(skb,
+				INT51X1_HEADER_SIZE,
+				need_tail,
+				flags);
+		dev_kfree_skb_any(skb);
+		if (!skb2)
+			return NULL;
+		skb = skb2;
+	}
+
+	pack_len += need_tail;
+	pack_len &= 0x07ff;
+
+	len = (__le16 *) __skb_push(skb, INT51X1_HEADER_SIZE);
+	*len = cpu_to_le16(pack_len);
+
+	if(need_tail)
+		memset(__skb_put(skb, need_tail), 0, need_tail);
+
+	return skb;
+}
+
+static void int51x1_async_cmd_callback(struct urb *urb)
+{
+	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
+	int status = urb->status;
+
+	if (status < 0)
+		dev_warn(&urb->dev->dev, "async callback failed with %d\n", status);
+
+	kfree(req);
+	usb_free_urb(urb);
+}
+
+static void int51x1_set_multicast(struct net_device *netdev)
+{
+	struct usb_ctrlrequest *req;
+	int status;
+	struct urb *urb;
+	struct usbnet *dev = netdev_priv(netdev);
+	u16 filter = PACKET_TYPE_DIRECTED | PACKET_TYPE_BROADCAST;
+
+	if (netdev->flags & IFF_PROMISC) {
+		/* do not expect to see traffic of other PLCs */
+		filter |= PACKET_TYPE_PROMISCUOUS;
+		devinfo(dev, "promiscuous mode enabled");
+	} else if (netdev->mc_count ||
+		  (netdev->flags & IFF_ALLMULTI)) {
+		filter |= PACKET_TYPE_ALL_MULTICAST;
+		devdbg(dev, "receive all multicast enabled");
+	} else {
+		/* ~PROMISCUOUS, ~MULTICAST */
+		devdbg(dev, "receive own packets only");
+	}
+
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb) {
+		devwarn(dev, "Error allocating URB");
+		return;
+	}
+
+	req = kmalloc(sizeof(*req), GFP_ATOMIC);
+	if (!req) {
+		devwarn(dev, "Error allocating control msg");
+		goto out;
+	}
+
+	req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
+	req->bRequest = SET_ETHERNET_PACKET_FILTER;
+	req->wValue = cpu_to_le16(filter);
+	req->wIndex = 0;
+	req->wLength = 0;
+
+	usb_fill_control_urb(urb, dev->udev, usb_sndctrlpipe(dev->udev, 0),
+		(void *)req, NULL, 0,
+		int51x1_async_cmd_callback,
+		(void *)req);
+
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+	if (status < 0) {
+		devwarn(dev, "Error submitting control msg, sts=%d", status);
+		goto out1;
+	}
+	return;
+out1:
+	kfree(req);
+out:
+	usb_free_urb(urb);
+}
+
+static const struct net_device_ops int51x1_netdev_ops = {
+	.ndo_open		= usbnet_open,
+	.ndo_stop		= usbnet_stop,
+	.ndo_start_xmit		= usbnet_start_xmit,
+	.ndo_tx_timeout		= usbnet_tx_timeout,
+	.ndo_change_mtu		= usbnet_change_mtu,
+	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_set_multicast_list	= int51x1_set_multicast,
+};
+
+static int int51x1_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	int status = usbnet_get_ethernet_addr(dev, 3);
+
+	if (status)
+		return status;
+
+	dev->net->hard_header_len += INT51X1_HEADER_SIZE;
+	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
+	dev->net->netdev_ops = &int51x1_netdev_ops;
+
+	return usbnet_get_endpoints(dev, intf);
+}
+
+static const struct driver_info int51x1_info = {
+	.description = "Intellon usb powerline adapter",
+	.bind        = int51x1_bind,
+	.rx_fixup    = int51x1_rx_fixup,
+	.tx_fixup    = int51x1_tx_fixup,
+	.in          = 1,
+	.out         = 2,
+	.flags       = FLAG_ETHER,
+};
+
+static const struct usb_device_id products[] = {
+	{
+	USB_DEVICE(INT51X1_VENDOR_ID, INT51X1_PRODUCT_ID),
+		.driver_info = (unsigned long) &int51x1_info,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver int51x1_driver = {
+	.name       = "int51x1",
+	.id_table   = products,
+	.probe      = usbnet_probe,
+	.disconnect = usbnet_disconnect,
+	.suspend    = usbnet_suspend,
+	.resume     = usbnet_resume,
+};
+
+static int __init int51x1_init(void)
+{
+	return usb_register(&int51x1_driver);
+}
+module_init(int51x1_init);
+
+static void __exit int51x1_exit(void)
+{
+	usb_deregister(&int51x1_driver);
+}
+module_exit(int51x1_exit);
+
+MODULE_AUTHOR("Peter Holik");
+MODULE_DESCRIPTION("Intellon usb powerline adapter");
+MODULE_LICENSE("GPL");