LXR linux/drivers/net/usb/cx82310

   1/*
   2 * Driver for USB ethernet port of Conexant CX82310-based ADSL routers
   3 * Copyright (C) 2010 by Ondrej Zary
   4 * some parts inspired by the cxacru driver
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/netdevice.h>
  22#include <linux/etherdevice.h>
  23#include <linux/ethtool.h>
  24#include <linux/workqueue.h>
  25#include <linux/mii.h>
  26#include <linux/usb.h>
  27#include <linux/usb/usbnet.h>
  28
  29enum cx82310_cmd {
  30        CMD_START               = 0x84, /* no effect? */
  31        CMD_STOP                = 0x85, /* no effect? */
  32        CMD_GET_STATUS          = 0x90, /* returns nothing? */
  33        CMD_GET_MAC_ADDR        = 0x91, /* read MAC address */
  34        CMD_GET_LINK_STATUS     = 0x92, /* not useful, link is always up */
  35        CMD_ETHERNET_MODE       = 0x99, /* unknown, needed during init */
  36};
  37
  38enum cx82310_status {
  39        STATUS_UNDEFINED,
  40        STATUS_SUCCESS,
  41        STATUS_ERROR,
  42        STATUS_UNSUPPORTED,
  43        STATUS_UNIMPLEMENTED,
  44        STATUS_PARAMETER_ERROR,
  45        STATUS_DBG_LOOPBACK,
  46};
  47
  48#define CMD_PACKET_SIZE 64
  49#define CMD_TIMEOUT     100
  50#define CMD_REPLY_RETRY 5
  51
  52#define CX82310_MTU     1514
  53#define CMD_EP          0x01
  54
  55/*
  56 * execute control command
  57 *  - optionally send some data (command parameters)
  58 *  - optionally wait for the reply
  59 *  - optionally read some data from the reply
  60 */
  61static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
  62                       u8 *wdata, int wlen, u8 *rdata, int rlen)
  63{
  64        int actual_len, retries, ret;
  65        struct usb_device *udev = dev->udev;
  66        u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
  67
  68        if (!buf)
  69                return -ENOMEM;
  70
  71        /* create command packet */
  72        buf[0] = cmd;
  73        if (wdata)
  74                memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
  75
  76        /* send command packet */
  77        ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
  78                           CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
  79        if (ret < 0) {
  80                if (cmd != CMD_GET_LINK_STATUS)
  81                        dev_err(&dev->udev->dev, "send command %#x: error %d\n",
  82                                cmd, ret);
  83                goto end;
  84        }
  85
  86        if (reply) {
  87                /* wait for reply, retry if it's empty */
  88                for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
  89                        ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
  90                                           buf, CMD_PACKET_SIZE, &actual_len,
  91                                           CMD_TIMEOUT);
  92                        if (ret < 0) {
  93                                if (cmd != CMD_GET_LINK_STATUS)
  94                                        dev_err(&dev->udev->dev,
  95                                                "reply receive error %d\n",
  96                                                ret);
  97                                goto end;
  98                        }
  99                        if (actual_len > 0)
 100                                break;
 101                }
 102                if (actual_len == 0) {
 103                        dev_err(&dev->udev->dev, "no reply to command %#x\n",
 104                                cmd);
 105                        ret = -EIO;
 106                        goto end;
 107                }
 108                if (buf[0] != cmd) {
 109                        dev_err(&dev->udev->dev,
 110                                "got reply to command %#x, expected: %#x\n",
 111                                buf[0], cmd);
 112                        ret = -EIO;
 113                        goto end;
 114                }
 115                if (buf[1] != STATUS_SUCCESS) {
 116                        dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
 117                                cmd, buf[1]);
 118                        ret = -EIO;
 119                        goto end;
 120                }
 121                if (rdata)
 122                        memcpy(rdata, buf + 4,
 123                               min_t(int, rlen, CMD_PACKET_SIZE - 4));
 124        }
 125end:
 126        kfree(buf);
 127        return ret;
 128}
 129
 130#define partial_len     data[0]         /* length of partial packet data */
 131#define partial_rem     data[1]         /* remaining (missing) data length */
 132#define partial_data    data[2]         /* partial packet data */
 133
 134static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
 135{
 136        int ret;
 137        char buf[15];
 138        struct usb_device *udev = dev->udev;
 139        u8 link[3];
 140        int timeout = 50;
 141
 142        /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
 143        if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
 144            && strcmp(buf, "USB NET CARD")) {
 145                dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
 146                return -ENODEV;
 147        }
 148
 149        ret = usbnet_get_endpoints(dev, intf);
 150        if (ret)
 151                return ret;
 152
 153        /*
 154         * this must not include ethernet header as the device can send partial
 155         * packets with no header (and sometimes even empty URBs)
 156         */
 157        dev->net->hard_header_len = 0;
 158        /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
 159        dev->hard_mtu = CX82310_MTU + 2;
 160        /* we can receive URBs up to 4KB from the device */
 161        dev->rx_urb_size = 4096;
 162
 163        dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
 164        if (!dev->partial_data)
 165                return -ENOMEM;
 166
 167        /* wait for firmware to become ready (indicated by the link being up) */
 168        while (--timeout) {
 169                ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0,
 170                                  link, sizeof(link));
 171                /* the command can time out during boot - it's not an error */
 172                if (!ret && link[0] == 1 && link[2] == 1)
 173                        break;
 174                msleep(500);
 175        }
 176        if (!timeout) {
 177                dev_err(&udev->dev, "firmware not ready in time\n");
 178                return -ETIMEDOUT;
 179        }
 180
 181        /* enable ethernet mode (?) */
 182        ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
 183        if (ret) {
 184                dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
 185                        ret);
 186                goto err;
 187        }
 188
 189        /* get the MAC address */
 190        ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
 191                          dev->net->dev_addr, ETH_ALEN);
 192        if (ret) {
 193                dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
 194                goto err;
 195        }
 196
 197        /* start (does not seem to have any effect?) */
 198        ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
 199        if (ret)
 200                goto err;
 201
 202        return 0;
 203err:
 204        kfree((void *)dev->partial_data);
 205        return ret;
 206}
 207
 208static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
 209{
 210        kfree((void *)dev->partial_data);
 211}
 212
 213/*
 214 * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
 215 * packet length at the beginning.
 216 * The last packet might be incomplete (when it crosses the 4KB URB size),
 217 * continuing in the next skb (without any headers).
 218 * If a packet has odd length, there is one extra byte at the end (before next
 219 * packet or at the end of the URB).
 220 */
 221static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 222{
 223        int len;
 224        struct sk_buff *skb2;
 225
 226        /*
 227         * If the last skb ended with an incomplete packet, this skb contains
 228         * end of that packet at the beginning.
 229         */
 230        if (dev->partial_rem) {
 231                len = dev->partial_len + dev->partial_rem;
 232                skb2 = alloc_skb(len, GFP_ATOMIC);
 233                if (!skb2)
 234                        return 0;
 235                skb_put(skb2, len);
 236                memcpy(skb2->data, (void *)dev->partial_data,
 237                       dev->partial_len);
 238                memcpy(skb2->data + dev->partial_len, skb->data,
 239                       dev->partial_rem);
 240                usbnet_skb_return(dev, skb2);
 241                skb_pull(skb, (dev->partial_rem + 1) & ~1);
 242                dev->partial_rem = 0;
 243                if (skb->len < 2)
 244                        return 1;
 245        }
 246
 247        /* a skb can contain multiple packets */
 248        while (skb->len > 1) {
 249                /* first two bytes are packet length */
 250                len = skb->data[0] | (skb->data[1] << 8);
 251                skb_pull(skb, 2);
 252
 253                /* if last packet in the skb, let usbnet to process it */
 254                if (len == skb->len || len + 1 == skb->len) {
 255                        skb_trim(skb, len);
 256                        break;
 257                }
 258
 259                if (len > CX82310_MTU) {
 260                        dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
 261                                len);
 262                        return 0;
 263                }
 264
 265                /* incomplete packet, save it for the next skb */
 266                if (len > skb->len) {
 267                        dev->partial_len = skb->len;
 268                        dev->partial_rem = len - skb->len;
 269                        memcpy((void *)dev->partial_data, skb->data,
 270                               dev->partial_len);
 271                        skb_pull(skb, skb->len);
 272                        break;
 273                }
 274
 275                skb2 = alloc_skb(len, GFP_ATOMIC);
 276                if (!skb2)
 277                        return 0;
 278                skb_put(skb2, len);
 279                memcpy(skb2->data, skb->data, len);
 280                /* process the packet */
 281                usbnet_skb_return(dev, skb2);
 282
 283                skb_pull(skb, (len + 1) & ~1);
 284        }
 285
 286        /* let usbnet process the last packet */
 287        return 1;
 288}
 289
 290/* TX is easy, just add 2 bytes of length at the beginning */
 291static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
 292                                       gfp_t flags)
 293{
 294        int len = skb->len;
 295
 296        if (skb_cow_head(skb, 2)) {
 297                dev_kfree_skb_any(skb);
 298                return NULL;
 299        }
 300        skb_push(skb, 2);
 301
 302        skb->data[0] = len;
 303        skb->data[1] = len >> 8;
 304
 305        return skb;
 306}
 307
 308
 309static const struct driver_info cx82310_info = {
 310        .description    = "Conexant CX82310 USB ethernet",
 311        .flags          = FLAG_ETHER,
 312        .bind           = cx82310_bind,
 313        .unbind         = cx82310_unbind,
 314        .rx_fixup       = cx82310_rx_fixup,
 315        .tx_fixup       = cx82310_tx_fixup,
 316};
 317
 318#define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
 319        .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
 320                       USB_DEVICE_ID_MATCH_DEV_INFO, \
 321        .idVendor = (vend), \
 322        .idProduct = (prod), \
 323        .bDeviceClass = (cl), \
 324        .bDeviceSubClass = (sc), \
 325        .bDeviceProtocol = (pr)
 326
 327static const struct usb_device_id products[] = {
 328        {
 329                USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
 330                .driver_info = (unsigned long) &cx82310_info
 331        },
 332        { },
 333};
 334MODULE_DEVICE_TABLE(usb, products);
 335
 336static struct usb_driver cx82310_driver = {
 337        .name           = "cx82310_eth",
 338        .id_table       = products,
 339        .probe          = usbnet_probe,
 340        .disconnect     = usbnet_disconnect,
 341        .suspend        = usbnet_suspend,
 342        .resume         = usbnet_resume,
 343        .disable_hub_initiated_lpm = 1,
 344};
 345
 346module_usb_driver(cx82310_driver);
 347
 348MODULE_AUTHOR("Ondrej Zary");
 349MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
 350MODULE_LICENSE("GPL");
 351