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