3 files changed, 363 insertions, 0 deletions

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index d7b7018a1de1..52ffabe6db0e 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -358,6 +358,14 @@ config USB_NET_ZAURUS
           really need this non-conformant variant of CDC Ethernet (or in
           some cases CDC MDLM) protocol, not "g_ether".
 
+config USB_NET_CX82310_ETH
+        tristate "Conexant CX82310 USB ethernet port"
+        depends on USB_USBNET
+        help
+          Choose this option if you're using a Conexant CX82310-based ADSL
+          router with USB ethernet port. This driver is for routers only,
+          it will not work with ADSL modems (use cxacru driver instead).
+
 config USB_HSO
         tristate "Option USB High Speed Mobile Devices"
         depends on USB && RFKILL
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index b13a279663ba..a19b0259ae16 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -25,4 +25,5 @@ obj-$(CONFIG_USB_NET_INT51X1)	+= int51x1.o
 obj-$(CONFIG_USB_CDC_PHONET)    += cdc-phonet.o
 obj-$(CONFIG_USB_IPHETH)        += ipheth.o
 obj-$(CONFIG_USB_SIERRA_NET)    += sierra_net.o
+obj-$(CONFIG_USB_NET_CX82310_ETH)       += cx82310_eth.o
 
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");