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 17 enum 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 26 enum 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 struct 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 */ 54 static 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 } 115 end: 116 kfree(buf); 117 return ret; 118 } 119 120 static 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 } 129 130 static 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 */ 140 141 static 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 u8 addr[ETH_ALEN]; 150 151 /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */ 152 if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0 153 && strcmp(buf, "USB NET CARD")) { 154 dev_info(&udev->dev, "ignoring: probably an ADSL modem\n"); 155 return -ENODEV; 156 } 157 158 ret = usbnet_get_endpoints(dev, intf); 159 if (ret) 160 return ret; 161 162 /* 163 * this must not include ethernet header as the device can send partial 164 * packets with no header (and sometimes even empty URBs) 165 */ 166 dev->net->hard_header_len = 0; 167 /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */ 168 dev->hard_mtu = CX82310_MTU + 2; 169 /* we can receive URBs up to 4KB from the device */ 170 dev->rx_urb_size = 4096; 171 172 dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL); 173 if (!dev->partial_data) 174 return -ENOMEM; 175 176 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 177 if (!priv) { 178 ret = -ENOMEM; 179 goto err_partial; 180 } 181 dev->driver_priv = priv; 182 INIT_WORK(&priv->reenable_work, cx82310_reenable_work); 183 priv->dev = dev; 184 185 /* wait for firmware to become ready (indicated by the link being up) */ 186 while (--timeout) { 187 ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0, 188 link, sizeof(link)); 189 /* the command can time out during boot - it's not an error */ 190 if (!ret && link[0] == 1 && link[2] == 1) 191 break; 192 msleep(500); 193 } 194 if (!timeout) { 195 netdev_err(dev->net, "firmware not ready in time\n"); 196 ret = -ETIMEDOUT; 197 goto err; 198 } 199 200 /* enable ethernet mode (?) */ 201 ret = cx82310_enable_ethernet(dev); 202 if (ret) 203 goto err; 204 205 /* get the MAC address */ 206 ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0, addr, ETH_ALEN); 207 if (ret) { 208 netdev_err(dev->net, "unable to read MAC address: %d\n", ret); 209 goto err; 210 } 211 eth_hw_addr_set(dev->net, addr); 212 213 /* start (does not seem to have any effect?) */ 214 ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0); 215 if (ret) 216 goto err; 217 218 return 0; 219 err: 220 kfree(dev->driver_priv); 221 err_partial: 222 kfree((void *)dev->partial_data); 223 return ret; 224 } 225 226 static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf) 227 { 228 struct cx82310_priv *priv = dev->driver_priv; 229 230 kfree((void *)dev->partial_data); 231 cancel_work_sync(&priv->reenable_work); 232 kfree(dev->driver_priv); 233 } 234 235 /* 236 * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte 237 * packet length at the beginning. 238 * The last packet might be incomplete (when it crosses the 4KB URB size), 239 * continuing in the next skb (without any headers). 240 * If a packet has odd length, there is one extra byte at the end (before next 241 * packet or at the end of the URB). 242 */ 243 static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 244 { 245 int len; 246 struct sk_buff *skb2; 247 struct cx82310_priv *priv = dev->driver_priv; 248 249 /* 250 * If the last skb ended with an incomplete packet, this skb contains 251 * end of that packet at the beginning. 252 */ 253 if (dev->partial_rem) { 254 len = dev->partial_len + dev->partial_rem; 255 skb2 = alloc_skb(len, GFP_ATOMIC); 256 if (!skb2) 257 return 0; 258 skb_put(skb2, len); 259 memcpy(skb2->data, (void *)dev->partial_data, 260 dev->partial_len); 261 memcpy(skb2->data + dev->partial_len, skb->data, 262 dev->partial_rem); 263 usbnet_skb_return(dev, skb2); 264 skb_pull(skb, (dev->partial_rem + 1) & ~1); 265 dev->partial_rem = 0; 266 if (skb->len < 2) 267 return 1; 268 } 269 270 /* a skb can contain multiple packets */ 271 while (skb->len > 1) { 272 /* first two bytes are packet length */ 273 len = skb->data[0] | (skb->data[1] << 8); 274 skb_pull(skb, 2); 275 276 /* if last packet in the skb, let usbnet to process it */ 277 if (len == skb->len || len + 1 == skb->len) { 278 skb_trim(skb, len); 279 break; 280 } 281 282 if (len == 0xffff) { 283 netdev_info(dev->net, "router was rebooted, re-enabling ethernet mode"); 284 schedule_work(&priv->reenable_work); 285 } else if (len > CX82310_MTU) { 286 netdev_err(dev->net, "RX packet too long: %d B\n", len); 287 return 0; 288 } 289 290 /* incomplete packet, save it for the next skb */ 291 if (len > skb->len) { 292 dev->partial_len = skb->len; 293 dev->partial_rem = len - skb->len; 294 memcpy((void *)dev->partial_data, skb->data, 295 dev->partial_len); 296 skb_pull(skb, skb->len); 297 break; 298 } 299 300 skb2 = alloc_skb(len, GFP_ATOMIC); 301 if (!skb2) 302 return 0; 303 skb_put(skb2, len); 304 memcpy(skb2->data, skb->data, len); 305 /* process the packet */ 306 usbnet_skb_return(dev, skb2); 307 308 skb_pull(skb, (len + 1) & ~1); 309 } 310 311 /* let usbnet process the last packet */ 312 return 1; 313 } 314 315 /* TX is easy, just add 2 bytes of length at the beginning */ 316 static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb, 317 gfp_t flags) 318 { 319 int len = skb->len; 320 321 if (skb_cow_head(skb, 2)) { 322 dev_kfree_skb_any(skb); 323 return NULL; 324 } 325 skb_push(skb, 2); 326 327 skb->data[0] = len; 328 skb->data[1] = len >> 8; 329 330 return skb; 331 } 332 333 334 static const struct driver_info cx82310_info = { 335 .description = "Conexant CX82310 USB ethernet", 336 .flags = FLAG_ETHER, 337 .bind = cx82310_bind, 338 .unbind = cx82310_unbind, 339 .rx_fixup = cx82310_rx_fixup, 340 .tx_fixup = cx82310_tx_fixup, 341 }; 342 343 #define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \ 344 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \ 345 USB_DEVICE_ID_MATCH_DEV_INFO, \ 346 .idVendor = (vend), \ 347 .idProduct = (prod), \ 348 .bDeviceClass = (cl), \ 349 .bDeviceSubClass = (sc), \ 350 .bDeviceProtocol = (pr) 351 352 static const struct usb_device_id products[] = { 353 { 354 USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0), 355 .driver_info = (unsigned long) &cx82310_info 356 }, 357 { }, 358 }; 359 MODULE_DEVICE_TABLE(usb, products); 360 361 static struct usb_driver cx82310_driver = { 362 .name = "cx82310_eth", 363 .id_table = products, 364 .probe = usbnet_probe, 365 .disconnect = usbnet_disconnect, 366 .suspend = usbnet_suspend, 367 .resume = usbnet_resume, 368 .disable_hub_initiated_lpm = 1, 369 }; 370 371 module_usb_driver(cx82310_driver); 372 373 MODULE_AUTHOR("Ondrej Zary"); 374 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver"); 375 MODULE_LICENSE("GPL"); 376