LXR linux/drivers/net/usb/cx82310

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Driver for USB ethernet port of Conexant CX82310-based ADSL routers
   4 * Copyright (C) 2010 by Ondrej Zary
   5 * some parts inspired by the cxacru driver
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/netdevice.h>
  10#include <linux/etherdevice.h>
  11#include <linux/ethtool.h>
  12#include <linux/workqueue.h>
  13#include <linux/mii.h>
  14#include <linux/usb.h>
  15#include <linux/usb/usbnet.h>
  16
  17enum cx82310_cmd {
  18        CMD_START               = 0x84, /* no effect? */
  19        CMD_STOP                = 0x85, /* no effect? */
  20        CMD_GET_STATUS          = 0x90, /* returns nothing? */
  21        CMD_GET_MAC_ADDR        = 0x91, /* read MAC address */
  22        CMD_GET_LINK_STATUS     = 0x92, /* not useful, link is always up */
  23        CMD_ETHERNET_MODE       = 0x99, /* unknown, needed during init */
  24};
  25
  26enum cx82310_status {
  27        STATUS_UNDEFINED,
  28        STATUS_SUCCESS,
  29        STATUS_ERROR,
  30        STATUS_UNSUPPORTED,
  31        STATUS_UNIMPLEMENTED,
  32        STATUS_PARAMETER_ERROR,
  33        STATUS_DBG_LOOPBACK,
  34};
  35
  36#define CMD_PACKET_SIZE 64
  37#define CMD_TIMEOUT     100
  38#define CMD_REPLY_RETRY 5
  39
  40#define CX82310_MTU     1514
  41#define CMD_EP          0x01
  42
  43struct cx82310_priv {
  44        struct work_struct reenable_work;
  45        struct usbnet *dev;
  46};
  47
  48/*
  49 * execute control command
  50 *  - optionally send some data (command parameters)
  51 *  - optionally wait for the reply
  52 *  - optionally read some data from the reply
  53 */
  54static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
  55                       u8 *wdata, int wlen, u8 *rdata, int rlen)
  56{
  57        int actual_len, retries, ret;
  58        struct usb_device *udev = dev->udev;
  59        u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
  60
  61        if (!buf)
  62                return -ENOMEM;
  63
  64        /* create command packet */
  65        buf[0] = cmd;
  66        if (wdata)
  67                memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
  68
  69        /* send command packet */
  70        ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
  71                           CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
  72        if (ret < 0) {
  73                if (cmd != CMD_GET_LINK_STATUS)
  74                        netdev_err(dev->net, "send command %#x: error %d\n",
  75                                   cmd, ret);
  76                goto end;
  77        }
  78
  79        if (reply) {
  80                /* wait for reply, retry if it's empty */
  81                for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
  82                        ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
  83                                           buf, CMD_PACKET_SIZE, &actual_len,
  84                                           CMD_TIMEOUT);
  85                        if (ret < 0) {
  86                                if (cmd != CMD_GET_LINK_STATUS)
  87                                        netdev_err(dev->net, "reply receive error %d\n",
  88                                                   ret);
  89                                goto end;
  90                        }
  91                        if (actual_len > 0)
  92                                break;
  93                }
  94                if (actual_len == 0) {
  95                        netdev_err(dev->net, "no reply to command %#x\n", cmd);
  96                        ret = -EIO;
  97                        goto end;
  98                }
  99                if (buf[0] != cmd) {
 100                        netdev_err(dev->net, "got reply to command %#x, expected: %#x\n",
 101                                   buf[0], cmd);
 102                        ret = -EIO;
 103                        goto end;
 104                }
 105                if (buf[1] != STATUS_SUCCESS) {
 106                        netdev_err(dev->net, "command %#x failed: %#x\n", cmd,
 107                                   buf[1]);
 108                        ret = -EIO;
 109                        goto end;
 110                }
 111                if (rdata)
 112                        memcpy(rdata, buf + 4,
 113                               min_t(int, rlen, CMD_PACKET_SIZE - 4));
 114        }
 115end:
 116        kfree(buf);
 117        return ret;
 118}
 119
 120static int cx82310_enable_ethernet(struct usbnet *dev)
 121{
 122        int ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
 123
 124        if (ret)
 125                netdev_err(dev->net, "unable to enable ethernet mode: %d\n",
 126                           ret);
 127        return ret;
 128}
 129
 130static void cx82310_reenable_work(struct work_struct *work)
 131{
 132        struct cx82310_priv *priv = container_of(work, struct cx82310_priv,
 133                                                 reenable_work);
 134        cx82310_enable_ethernet(priv->dev);
 135}
 136
 137#define partial_len     data[0]         /* length of partial packet data */
 138#define partial_rem     data[1]         /* remaining (missing) data length */
 139#define partial_data    data[2]         /* partial packet data */
 140
 141static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
 142{
 143        int ret;
 144        char buf[15];
 145        struct usb_device *udev = dev->udev;
 146        u8 link[3];
 147        int timeout = 50;
 148        struct cx82310_priv *priv;
 149
 150        /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
 151        if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
 152            && strcmp(buf, "USB NET CARD")) {
 153                dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
 154                return -ENODEV;
 155        }
 156
 157        ret = usbnet_get_endpoints(dev, intf);
 158        if (ret)
 159                return ret;
 160
 161        /*
 162         * this must not include ethernet header as the device can send partial
 163         * packets with no header (and sometimes even empty URBs)
 164         */
 165        dev->net->hard_header_len = 0;
 166        /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
 167        dev->hard_mtu = CX82310_MTU + 2;
 168        /* we can receive URBs up to 4KB from the device */
 169        dev->rx_urb_size = 4096;
 170
 171        dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
 172        if (!dev->partial_data)
 173                return -ENOMEM;
 174
 175        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 176        if (!priv) {
 177                ret = -ENOMEM;
 178                goto err_partial;
 179        }
 180        dev->driver_priv = priv;
 181        INIT_WORK(&priv->reenable_work, cx82310_reenable_work);
 182        priv->dev = dev;
 183
 184        /* wait for firmware to become ready (indicated by the link being up) */
 185        while (--timeout) {
 186                ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0,
 187                                  link, sizeof(link));
 188                /* the command can time out during boot - it's not an error */
 189                if (!ret && link[0] == 1 && link[2] == 1)
 190                        break;
 191                msleep(500);
 192        }
 193        if (!timeout) {
 194                netdev_err(dev->net, "firmware not ready in time\n");
 195                ret = -ETIMEDOUT;
 196                goto err;
 197        }
 198
 199        /* enable ethernet mode (?) */
 200        ret = cx82310_enable_ethernet(dev);
 201        if (ret)
 202                goto err;
 203
 204        /* get the MAC address */
 205        ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
 206                          dev->net->dev_addr, ETH_ALEN);
 207        if (ret) {
 208                netdev_err(dev->net, "unable to read MAC address: %d\n", ret);
 209                goto err;
 210        }
 211
 212        /* start (does not seem to have any effect?) */
 213        ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
 214        if (ret)
 215                goto err;
 216
 217        return 0;
 218err:
 219        kfree(dev->driver_priv);
 220err_partial:
 221        kfree((void *)dev->partial_data);
 222        return ret;
 223}
 224
 225static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
 226{
 227        struct cx82310_priv *priv = dev->driver_priv;
 228
 229        kfree((void *)dev->partial_data);
 230        cancel_work_sync(&priv->reenable_work);
 231        kfree(dev->driver_priv);
 232}
 233
 234/*
 235 * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
 236 * packet length at the beginning.
 237 * The last packet might be incomplete (when it crosses the 4KB URB size),
 238 * continuing in the next skb (without any headers).
 239 * If a packet has odd length, there is one extra byte at the end (before next
 240 * packet or at the end of the URB).
 241 */
 242static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 243{
 244        int len;
 245        struct sk_buff *skb2;
 246        struct cx82310_priv *priv = dev->driver_priv;
 247
 248        /*
 249         * If the last skb ended with an incomplete packet, this skb contains
 250         * end of that packet at the beginning.
 251         */
 252        if (dev->partial_rem) {
 253                len = dev->partial_len + dev->partial_rem;
 254                skb2 = alloc_skb(len, GFP_ATOMIC);
 255                if (!skb2)
 256                        return 0;
 257                skb_put(skb2, len);
 258                memcpy(skb2->data, (void *)dev->partial_data,
 259                       dev->partial_len);
 260                memcpy(skb2->data + dev->partial_len, skb->data,
 261                       dev->partial_rem);
 262                usbnet_skb_return(dev, skb2);
 263                skb_pull(skb, (dev->partial_rem + 1) & ~1);
 264                dev->partial_rem = 0;
 265                if (skb->len < 2)
 266                        return 1;
 267        }
 268
 269        /* a skb can contain multiple packets */
 270        while (skb->len > 1) {
 271                /* first two bytes are packet length */
 272                len = skb->data[0] | (skb->data[1] << 8);
 273                skb_pull(skb, 2);
 274
 275                /* if last packet in the skb, let usbnet to process it */
 276                if (len == skb->len || len + 1 == skb->len) {
 277                        skb_trim(skb, len);
 278                        break;
 279                }
 280
 281                if (len == 0xffff) {
 282                        netdev_info(dev->net, "router was rebooted, re-enabling ethernet mode");
 283                        schedule_work(&priv->reenable_work);
 284                } else if (len > CX82310_MTU) {
 285                        netdev_err(dev->net, "RX packet too long: %d B\n", len);
 286                        return 0;
 287                }
 288
 289                /* incomplete packet, save it for the next skb */
 290                if (len > skb->len) {
 291                        dev->partial_len = skb->len;
 292                        dev->partial_rem = len - skb->len;
 293                        memcpy((void *)dev->partial_data, skb->data,
 294                               dev->partial_len);
 295                        skb_pull(skb, skb->len);
 296                        break;
 297                }
 298
 299                skb2 = alloc_skb(len, GFP_ATOMIC);
 300                if (!skb2)
 301                        return 0;
 302                skb_put(skb2, len);
 303                memcpy(skb2->data, skb->data, len);
 304                /* process the packet */
 305                usbnet_skb_return(dev, skb2);
 306
 307                skb_pull(skb, (len + 1) & ~1);
 308        }
 309
 310        /* let usbnet process the last packet */
 311        return 1;
 312}
 313
 314/* TX is easy, just add 2 bytes of length at the beginning */
 315static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
 316                                       gfp_t flags)
 317{
 318        int len = skb->len;
 319
 320        if (skb_cow_head(skb, 2)) {
 321                dev_kfree_skb_any(skb);
 322                return NULL;
 323        }
 324        skb_push(skb, 2);
 325
 326        skb->data[0] = len;
 327        skb->data[1] = len >> 8;
 328
 329        return skb;
 330}
 331
 332
 333static const struct driver_info cx82310_info = {
 334        .description    = "Conexant CX82310 USB ethernet",
 335        .flags          = FLAG_ETHER,
 336        .bind           = cx82310_bind,
 337        .unbind         = cx82310_unbind,
 338        .rx_fixup       = cx82310_rx_fixup,
 339        .tx_fixup       = cx82310_tx_fixup,
 340};
 341
 342#define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
 343        .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
 344                       USB_DEVICE_ID_MATCH_DEV_INFO, \
 345        .idVendor = (vend), \
 346        .idProduct = (prod), \
 347        .bDeviceClass = (cl), \
 348        .bDeviceSubClass = (sc), \
 349        .bDeviceProtocol = (pr)
 350
 351static const struct usb_device_id products[] = {
 352        {
 353                USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
 354                .driver_info = (unsigned long) &cx82310_info
 355        },
 356        { },
 357};
 358MODULE_DEVICE_TABLE(usb, products);
 359
 360static struct usb_driver cx82310_driver = {
 361        .name           = "cx82310_eth",
 362        .id_table       = products,
 363        .probe          = usbnet_probe,
 364        .disconnect     = usbnet_disconnect,
 365        .suspend        = usbnet_suspend,
 366        .resume         = usbnet_resume,
 367        .disable_hub_initiated_lpm = 1,
 368};
 369
 370module_usb_driver(cx82310_driver);
 371
 372MODULE_AUTHOR("Ondrej Zary");
 373MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
 374MODULE_LICENSE("GPL");
 375