Initial import

1 files changed, 381 insertions, 0 deletions

diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c
new file mode 100644
index 000000000..f7180f8db
--- /dev/null
+++ b/drivers/net/usb/cdc_eem.c
@@ -0,0 +1,381 @@
+/*
+ * USB CDC EEM network interface driver
+ * Copyright (C) 2009 Oberthur Technologies
+ * by Omar Laazimani, Olivier Condemine
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ctype.h>
+#include <linux/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/crc32.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/usbnet.h>
+#include <linux/gfp.h>
+#include <linux/if_vlan.h>
+
+
+/*
+ * This driver is an implementation of the CDC "Ethernet Emulation
+ * Model" (EEM) specification, which encapsulates Ethernet frames
+ * for transport over USB using a simpler USB device model than the
+ * previous CDC "Ethernet Control Model" (ECM, or "CDC Ethernet").
+ *
+ * For details, see www.usb.org/developers/devclass_docs/CDC_EEM10.pdf
+ *
+ * This version has been tested with GIGAntIC WuaoW SIM Smart Card on 2.6.24,
+ * 2.6.27 and 2.6.30rc2 kernel.
+ * It has also been validated on Openmoko Om 2008.12 (based on 2.6.24 kernel).
+ * build on 23-April-2009
+ */
+
+#define EEM_HEAD	2		/* 2 byte header */
+
+/*-------------------------------------------------------------------------*/
+
+static void eem_linkcmd_complete(struct urb *urb)
+{
+	dev_kfree_skb(urb->context);
+	usb_free_urb(urb);
+}
+
+static void eem_linkcmd(struct usbnet *dev, struct sk_buff *skb)
+{
+	struct urb		*urb;
+	int			status;
+
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb)
+		goto fail;
+
+	usb_fill_bulk_urb(urb, dev->udev, dev->out,
+			skb->data, skb->len, eem_linkcmd_complete, skb);
+
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+	if (status) {
+		usb_free_urb(urb);
+fail:
+		dev_kfree_skb(skb);
+		netdev_warn(dev->net, "link cmd failure\n");
+		return;
+	}
+}
+
+static int eem_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	int status = 0;
+
+	status = usbnet_get_endpoints(dev, intf);
+	if (status < 0) {
+		usb_set_intfdata(intf, NULL);
+		usb_driver_release_interface(driver_of(intf), intf);
+		return status;
+	}
+
+	/* no jumbogram (16K) support for now */
+
+	dev->net->hard_header_len += EEM_HEAD + ETH_FCS_LEN + VLAN_HLEN;
+	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
+
+	return 0;
+}
+
+/*
+ * EEM permits packing multiple Ethernet frames into USB transfers
+ * (a "bundle"), but for TX we don't try to do that.
+ */
+static struct sk_buff *eem_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
+				       gfp_t flags)
+{
+	struct sk_buff	*skb2 = NULL;
+	u16		len = skb->len;
+	u32		crc = 0;
+	int		padlen = 0;
+
+	/* When ((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket) is
+	 * zero, stick two bytes of zero length EEM packet on the end.
+	 * Else the framework would add invalid single byte padding,
+	 * since it can't know whether ZLPs will be handled right by
+	 * all the relevant hardware and software.
+	 */
+	if (!((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket))
+		padlen += 2;
+
+	if (!skb_cloned(skb)) {
+		int	headroom = skb_headroom(skb);
+		int	tailroom = skb_tailroom(skb);
+
+		if ((tailroom >= ETH_FCS_LEN + padlen) &&
+		    (headroom >= EEM_HEAD))
+			goto done;
+
+		if ((headroom + tailroom)
+				> (EEM_HEAD + ETH_FCS_LEN + padlen)) {
+			skb->data = memmove(skb->head +
+					EEM_HEAD,
+					skb->data,
+					skb->len);
+			skb_set_tail_pointer(skb, len);
+			goto done;
+		}
+	}
+
+	skb2 = skb_copy_expand(skb, EEM_HEAD, ETH_FCS_LEN + padlen, flags);
+	if (!skb2)
+		return NULL;
+
+	dev_kfree_skb_any(skb);
+	skb = skb2;
+
+done:
+	/* we don't use the "no Ethernet CRC" option */
+	crc = crc32_le(~0, skb->data, skb->len);
+	crc = ~crc;
+
+	put_unaligned_le32(crc, skb_put(skb, 4));
+
+	/* EEM packet header format:
+	 * b0..13:	length of ethernet frame
+	 * b14:		bmCRC (1 == valid Ethernet CRC)
+	 * b15:		bmType (0 == data)
+	 */
+	len = skb->len;
+	put_unaligned_le16(BIT(14) | len, skb_push(skb, 2));
+
+	/* Bundle a zero length EEM packet if needed */
+	if (padlen)
+		put_unaligned_le16(0, skb_put(skb, 2));
+
+	return skb;
+}
+
+static int eem_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+	/*
+	 * Our task here is to strip off framing, leaving skb with one
+	 * data frame for the usbnet framework code to process.  But we
+	 * may have received multiple EEM payloads, or command payloads.
+	 * So we must process _everything_ as if it's a header, except
+	 * maybe the last data payload
+	 *
+	 * REVISIT the framework needs updating so that when we consume
+	 * all payloads (the last or only message was a command, or a
+	 * zero length EEM packet) that is not accounted as an rx_error.
+	 */
+	do {
+		struct sk_buff	*skb2 = NULL;
+		u16		header;
+		u16		len = 0;
+
+		/* incomplete EEM header? */
+		if (skb->len < EEM_HEAD)
+			return 0;
+
+		/*
+		 * EEM packet header format:
+		 * b0..14:	EEM type dependent (Data or Command)
+		 * b15:		bmType
+		 */
+		header = get_unaligned_le16(skb->data);
+		skb_pull(skb, EEM_HEAD);
+
+		/*
+		 * The bmType bit helps to denote when EEM
+		 * packet is data or command :
+		 *	bmType = 0	: EEM data payload
+		 *	bmType = 1	: EEM (link) command
+		 */
+		if (header & BIT(15)) {
+			u16	bmEEMCmd;
+
+			/*
+			 * EEM (link) command packet:
+			 * b0..10:	bmEEMCmdParam
+			 * b11..13:	bmEEMCmd
+			 * b14:		bmReserved (must be 0)
+			 * b15:		1 (EEM command)
+			 */
+			if (header & BIT(14)) {
+				netdev_dbg(dev->net, "reserved command %04x\n",
+					   header);
+				continue;
+			}
+
+			bmEEMCmd = (header >> 11) & 0x7;
+			switch (bmEEMCmd) {
+
+			/* Responding to echo requests is mandatory. */
+			case 0:		/* Echo command */
+				len = header & 0x7FF;
+
+				/* bogus command? */
+				if (skb->len < len)
+					return 0;
+
+				skb2 = skb_clone(skb, GFP_ATOMIC);
+				if (unlikely(!skb2))
+					goto next;
+				skb_trim(skb2, len);
+				put_unaligned_le16(BIT(15) | (1 << 11) | len,
+						skb_push(skb2, 2));
+				eem_linkcmd(dev, skb2);
+				break;
+
+			/*
+			 * Host may choose to ignore hints.
+			 *  - suspend: peripheral ready to suspend
+			 *  - response: suggest N millisec polling
+			 *  - response complete: suggest N sec polling
+			 *
+			 * Suspend is reported and maybe heeded.
+			 */
+			case 2:		/* Suspend hint */
+				usbnet_device_suggests_idle(dev);
+				continue;
+			case 3:		/* Response hint */
+			case 4:		/* Response complete hint */
+				continue;
+
+			/*
+			 * Hosts should never receive host-to-peripheral
+			 * or reserved command codes; or responses to an
+			 * echo command we didn't send.
+			 */
+			case 1:		/* Echo response */
+			case 5:		/* Tickle */
+			default:	/* reserved */
+				netdev_warn(dev->net,
+					    "unexpected link command %d\n",
+					    bmEEMCmd);
+				continue;
+			}
+
+		} else {
+			u32	crc, crc2;
+			int	is_last;
+
+			/* zero length EEM packet? */
+			if (header == 0)
+				continue;
+
+			/*
+			 * EEM data packet header :
+			 * b0..13:	length of ethernet frame
+			 * b14:		bmCRC
+			 * b15:		0 (EEM data)
+			 */
+			len = header & 0x3FFF;
+
+			/* bogus EEM payload? */
+			if (skb->len < len)
+				return 0;
+
+			/* bogus ethernet frame? */
+			if (len < (ETH_HLEN + ETH_FCS_LEN))
+				goto next;
+
+			/*
+			 * Treat the last payload differently: framework
+			 * code expects our "fixup" to have stripped off
+			 * headers, so "skb" is a data packet (or error).
+			 * Else if it's not the last payload, keep "skb"
+			 * for further processing.
+			 */
+			is_last = (len == skb->len);
+			if (is_last)
+				skb2 = skb;
+			else {
+				skb2 = skb_clone(skb, GFP_ATOMIC);
+				if (unlikely(!skb2))
+					return 0;
+			}
+
+			/*
+			 * The bmCRC helps to denote when the CRC field in
+			 * the Ethernet frame contains a calculated CRC:
+			 *	bmCRC = 1	: CRC is calculated
+			 *	bmCRC = 0	: CRC = 0xDEADBEEF
+			 */
+			if (header & BIT(14)) {
+				crc = get_unaligned_le32(skb2->data
+						+ len - ETH_FCS_LEN);
+				crc2 = ~crc32_le(~0, skb2->data, skb2->len
+						- ETH_FCS_LEN);
+			} else {
+				crc = get_unaligned_be32(skb2->data
+						+ len - ETH_FCS_LEN);
+				crc2 = 0xdeadbeef;
+			}
+			skb_trim(skb2, len - ETH_FCS_LEN);
+
+			if (is_last)
+				return crc == crc2;
+
+			if (unlikely(crc != crc2)) {
+				dev->net->stats.rx_errors++;
+				dev_kfree_skb_any(skb2);
+			} else
+				usbnet_skb_return(dev, skb2);
+		}
+
+next:
+		skb_pull(skb, len);
+	} while (skb->len);
+
+	return 1;
+}
+
+static const struct driver_info eem_info = {
+	.description =	"CDC EEM Device",
+	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT,
+	.bind =		eem_bind,
+	.rx_fixup =	eem_rx_fixup,
+	.tx_fixup =	eem_tx_fixup,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static const struct usb_device_id products[] = {
+{
+	USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_EEM,
+			USB_CDC_PROTO_EEM),
+	.driver_info = (unsigned long) &eem_info,
+},
+{
+	/* EMPTY == end of list */
+},
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver eem_driver = {
+	.name =		"cdc_eem",
+	.id_table =	products,
+	.probe =	usbnet_probe,
+	.disconnect =	usbnet_disconnect,
+	.suspend =	usbnet_suspend,
+	.resume =	usbnet_resume,
+	.disable_hub_initiated_lpm = 1,
+};
+
+module_usb_driver(eem_driver);
+
+MODULE_AUTHOR("Omar Laazimani <omar.oberthur@gmail.com>");
+MODULE_DESCRIPTION("USB CDC EEM");
+MODULE_LICENSE("GPL");