1 files changed, 354 insertions, 0 deletions
diff --git a/drivers/net/usb/cx82310_eth.c b/drivers/net/usb/cx82310_eth.c
new file mode 100644
index 000000000000..6fbe03276b27
--- /dev/null
+++ b/drivers/net/usb/cx82310_eth.c
@@ -0,0 +1,354 @@
+/*
+ * Driver for USB ethernet port of Conexant CX82310-based ADSL routers
+ * Copyright (C) 2010 by Ondrej Zary
+ * some parts inspired by the cxacru driver
+ *
+ * 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/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/usbnet.h>
+
+enum cx82310_cmd {
+	CMD_START		= 0x84,	/* no effect? */
+	CMD_STOP		= 0x85,	/* no effect? */
+	CMD_GET_STATUS		= 0x90,	/* returns nothing? */
+	CMD_GET_MAC_ADDR	= 0x91,	/* read MAC address */
+	CMD_GET_LINK_STATUS	= 0x92,	/* not useful, link is always up */
+	CMD_ETHERNET_MODE	= 0x99,	/* unknown, needed during init */
+};
+
+enum cx82310_status {
+	STATUS_UNDEFINED,
+	STATUS_SUCCESS,
+	STATUS_ERROR,
+	STATUS_UNSUPPORTED,
+	STATUS_UNIMPLEMENTED,
+	STATUS_PARAMETER_ERROR,
+	STATUS_DBG_LOOPBACK,
+};
+
+#define CMD_PACKET_SIZE	64
+/* first command after power on can take around 8 seconds */
+#define CMD_TIMEOUT	15000
+#define CMD_REPLY_RETRY 5
+
+#define CX82310_MTU	1514
+#define CMD_EP		0x01
+
+/*
+ * execute control command
+ *  - optionally send some data (command parameters)
+ *  - optionally wait for the reply
+ *  - optionally read some data from the reply
+ */
+static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
+		       u8 *wdata, int wlen, u8 *rdata, int rlen)
+{
+	int actual_len, retries, ret;
+	struct usb_device *udev = dev->udev;
+	u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
+
+	if (!buf)
+		return -ENOMEM;
+
+	/* create command packet */
+	buf[0] = cmd;
+	if (wdata)
+		memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
+
+	/* send command packet */
+	ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
+			   CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
+	if (ret < 0) {
+		dev_err(&dev->udev->dev, "send command %#x: error %d\n",
+			cmd, ret);
+		goto end;
+	}
+
+	if (reply) {
+		/* wait for reply, retry if it's empty */
+		for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
+			ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
+					   buf, CMD_PACKET_SIZE, &actual_len,
+					   CMD_TIMEOUT);
+			if (ret < 0) {
+				dev_err(&dev->udev->dev,
+					"reply receive error %d\n", ret);
+				goto end;
+			}
+			if (actual_len > 0)
+				break;
+		}
+		if (actual_len == 0) {
+			dev_err(&dev->udev->dev, "no reply to command %#x\n",
+				cmd);
+			ret = -EIO;
+			goto end;
+		}
+		if (buf[0] != cmd) {
+			dev_err(&dev->udev->dev,
+				"got reply to command %#x, expected: %#x\n",
+				buf[0], cmd);
+			ret = -EIO;
+			goto end;
+		}
+		if (buf[1] != STATUS_SUCCESS) {
+			dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
+				cmd, buf[1]);
+			ret = -EIO;
+			goto end;
+		}
+		if (rdata)
+			memcpy(rdata, buf + 4,
+			       min_t(int, rlen, CMD_PACKET_SIZE - 4));
+	}
+end:
+	kfree(buf);
+	return ret;
+}
+
+#define partial_len	data[0]		/* length of partial packet data */
+#define partial_rem	data[1]		/* remaining (missing) data length */
+#define partial_data	data[2]		/* partial packet data */
+
+static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	int ret;
+	char buf[15];
+	struct usb_device *udev = dev->udev;
+
+	/* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
+	if (udev->descriptor.iProduct &&
+	    usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) &&
+	    strcmp(buf, "USB NET CARD")) {
+		dev_err(&udev->dev,
+			"probably an ADSL modem, use cxacru driver instead\n");
+		return -ENODEV;
+	}
+
+	ret = usbnet_get_endpoints(dev, intf);
+	if (ret)
+		return ret;
+
+	/*
+	 * this must not include ethernet header as the device can send partial
+	 * packets with no header (URB is at least 2 bytes long, so 2 is OK)
+	 */
+	dev->net->hard_header_len = 2;
+	/* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
+	dev->hard_mtu = CX82310_MTU + dev->net->hard_header_len;
+	/* we can receive URBs up to 4KB from the device */
+	dev->rx_urb_size = 4096;
+
+	dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
+	if (!dev->partial_data)
+		return -ENOMEM;
+
+	/* enable ethernet mode (?) */
+	ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
+	if (ret) {
+		dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
+			ret);
+		goto err;
+	}
+
+	/* get the MAC address */
+	ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
+			  dev->net->dev_addr, ETH_ALEN);
+	if (ret) {
+		dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
+		goto err;
+	}
+
+	/* start (does not seem to have any effect?) */
+	ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	kfree((void *)dev->partial_data);
+	return ret;
+}
+
+static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+	kfree((void *)dev->partial_data);
+}
+
+/*
+ * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
+ * packet length at the beginning.
+ * The last packet might be incomplete (when it crosses the 4KB URB size),
+ * continuing in the next skb (without any headers).
+ * If a packet has odd length, there is one extra byte at the end (before next
+ * packet or at the end of the URB).
+ */
+static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+	int len;
+	struct sk_buff *skb2;
+
+	/*
+	 * If the last skb ended with an incomplete packet, this skb contains
+	 * end of that packet at the beginning.
+	 */
+	if (dev->partial_rem) {
+		len = dev->partial_len + dev->partial_rem;
+		skb2 = alloc_skb(len, GFP_ATOMIC);
+		if (!skb2)
+			return 0;
+		skb_put(skb2, len);
+		memcpy(skb2->data, (void *)dev->partial_data,
+		       dev->partial_len);
+		memcpy(skb2->data + dev->partial_len, skb->data,
+		       dev->partial_rem);
+		usbnet_skb_return(dev, skb2);
+		skb_pull(skb, (dev->partial_rem + 1) & ~1);
+		dev->partial_rem = 0;
+		if (skb->len < 2)
+			return 1;
+	}
+
+	if (skb->len < 2) {
+		dev_err(&dev->udev->dev, "RX frame too short: %d B\n",
+			skb->len);
+		return 0;
+	}
+
+	/* a skb can contain multiple packets */
+	while (skb->len > 1) {
+		/* first two bytes are packet length */
+		len = skb->data[0] | (skb->data[1] << 8);
+		skb_pull(skb, 2);
+
+		/* if last packet in the skb, let usbnet to process it */
+		if (len == skb->len || len + 1 == skb->len) {
+			skb_trim(skb, len);
+			break;
+		}
+
+		if (len > CX82310_MTU) {
+			dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
+				len);
+			return 0;
+		}
+
+		/* incomplete packet, save it for the next skb */
+		if (len > skb->len) {
+			dev->partial_len = skb->len;
+			dev->partial_rem = len - skb->len;
+			memcpy((void *)dev->partial_data, skb->data,
+			       dev->partial_len);
+			skb_pull(skb, skb->len);
+			break;
+		}
+
+		skb2 = alloc_skb(len, GFP_ATOMIC);
+		if (!skb2)
+			return 0;
+		skb_put(skb2, len);
+		memcpy(skb2->data, skb->data, len);
+		/* process the packet */
+		usbnet_skb_return(dev, skb2);
+
+		skb_pull(skb, (len + 1) & ~1);
+	}
+
+	/* let usbnet process the last packet */
+	return 1;
+}
+
+/* TX is easy, just add 2 bytes of length at the beginning */
+static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
+				       gfp_t flags)
+{
+	int len = skb->len;
+
+	if (skb_headroom(skb) < 2) {
+		struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags);
+		dev_kfree_skb_any(skb);
+		skb = skb2;
+		if (!skb)
+			return NULL;
+	}
+	skb_push(skb, 2);
+
+	skb->data[0] = len;
+	skb->data[1] = len >> 8;
+
+	return skb;
+}
+
+
+static const struct driver_info	cx82310_info = {
+	.description	= "Conexant CX82310 USB ethernet",
+	.flags		= FLAG_ETHER,
+	.bind		= cx82310_bind,
+	.unbind		= cx82310_unbind,
+	.rx_fixup	= cx82310_rx_fixup,
+	.tx_fixup	= cx82310_tx_fixup,
+};
+
+#define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
+	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
+		       USB_DEVICE_ID_MATCH_DEV_INFO, \
+	.idVendor = (vend), \
+	.idProduct = (prod), \
+	.bDeviceClass = (cl), \
+	.bDeviceSubClass = (sc), \
+	.bDeviceProtocol = (pr)
+
+static const struct usb_device_id products[] = {
+	{
+		USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
+		.driver_info = (unsigned long) &cx82310_info
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver cx82310_driver = {
+	.name		= "cx82310_eth",
+	.id_table	= products,
+	.probe		= usbnet_probe,
+	.disconnect	= usbnet_disconnect,
+	.suspend	= usbnet_suspend,
+	.resume		= usbnet_resume,
+};
+
+static int __init cx82310_init(void)
+{
+	return usb_register(&cx82310_driver);
+}
+module_init(cx82310_init);
+
+static void __exit cx82310_exit(void)
+{
+	usb_deregister(&cx82310_driver);
+}
+module_exit(cx82310_exit);
+
+MODULE_AUTHOR("Ondrej Zary");
+MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
+MODULE_LICENSE("GPL");