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 /* 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 */ 49 static 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 } 113 end: 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 */ 121 122 static 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; 192 err: 193 kfree((void *)dev->partial_data); 194 return ret; 195 } 196 197 static 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 */ 210 static 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 */ 280 static 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 } 296 297 298 static 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) 315 316 static 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 }; 323 MODULE_DEVICE_TABLE(usb, products); 324 325 static 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 }; 334 335 module_usb_driver(cx82310_driver); 336 337 MODULE_AUTHOR("Ondrej Zary"); 338 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver"); 339 MODULE_LICENSE("GPL"); 340