1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * phonet.c -- USB CDC Phonet host driver 4 * 5 * Copyright (C) 2008-2009 Nokia Corporation. All rights reserved. 6 * 7 * Author: Rémi Denis-Courmont 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/mm.h> 12 #include <linux/module.h> 13 #include <linux/gfp.h> 14 #include <linux/usb.h> 15 #include <linux/usb/cdc.h> 16 #include <linux/netdevice.h> 17 #include <linux/if_arp.h> 18 #include <linux/if_phonet.h> 19 #include <linux/phonet.h> 20 21 #define PN_MEDIA_USB 0x1B 22 23 static const unsigned rxq_size = 17; 24 25 struct usbpn_dev { 26 struct net_device *dev; 27 28 struct usb_interface *intf, *data_intf; 29 struct usb_device *usb; 30 unsigned int tx_pipe, rx_pipe; 31 u8 active_setting; 32 u8 disconnected; 33 34 unsigned tx_queue; 35 spinlock_t tx_lock; 36 37 spinlock_t rx_lock; 38 struct sk_buff *rx_skb; 39 struct urb *urbs[]; 40 }; 41 42 static void tx_complete(struct urb *req); 43 static void rx_complete(struct urb *req); 44 45 /* 46 * Network device callbacks 47 */ 48 static netdev_tx_t usbpn_xmit(struct sk_buff *skb, struct net_device *dev) 49 { 50 struct usbpn_dev *pnd = netdev_priv(dev); 51 struct urb *req = NULL; 52 unsigned long flags; 53 int err; 54 55 if (skb->protocol != htons(ETH_P_PHONET)) 56 goto drop; 57 58 req = usb_alloc_urb(0, GFP_ATOMIC); 59 if (!req) 60 goto drop; 61 usb_fill_bulk_urb(req, pnd->usb, pnd->tx_pipe, skb->data, skb->len, 62 tx_complete, skb); 63 req->transfer_flags = URB_ZERO_PACKET; 64 err = usb_submit_urb(req, GFP_ATOMIC); 65 if (err) { 66 usb_free_urb(req); 67 goto drop; 68 } 69 70 spin_lock_irqsave(&pnd->tx_lock, flags); 71 pnd->tx_queue++; 72 if (pnd->tx_queue >= dev->tx_queue_len) 73 netif_stop_queue(dev); 74 spin_unlock_irqrestore(&pnd->tx_lock, flags); 75 return NETDEV_TX_OK; 76 77 drop: 78 dev_kfree_skb(skb); 79 dev->stats.tx_dropped++; 80 return NETDEV_TX_OK; 81 } 82 83 static void tx_complete(struct urb *req) 84 { 85 struct sk_buff *skb = req->context; 86 struct net_device *dev = skb->dev; 87 struct usbpn_dev *pnd = netdev_priv(dev); 88 int status = req->status; 89 unsigned long flags; 90 91 switch (status) { 92 case 0: 93 dev->stats.tx_bytes += skb->len; 94 break; 95 96 case -ENOENT: 97 case -ECONNRESET: 98 case -ESHUTDOWN: 99 dev->stats.tx_aborted_errors++; 100 fallthrough; 101 default: 102 dev->stats.tx_errors++; 103 dev_dbg(&dev->dev, "TX error (%d)\n", status); 104 } 105 dev->stats.tx_packets++; 106 107 spin_lock_irqsave(&pnd->tx_lock, flags); 108 pnd->tx_queue--; 109 netif_wake_queue(dev); 110 spin_unlock_irqrestore(&pnd->tx_lock, flags); 111 112 dev_kfree_skb_any(skb); 113 usb_free_urb(req); 114 } 115 116 static int rx_submit(struct usbpn_dev *pnd, struct urb *req, gfp_t gfp_flags) 117 { 118 struct net_device *dev = pnd->dev; 119 struct page *page; 120 int err; 121 122 page = __dev_alloc_page(gfp_flags | __GFP_NOMEMALLOC); 123 if (!page) 124 return -ENOMEM; 125 126 usb_fill_bulk_urb(req, pnd->usb, pnd->rx_pipe, page_address(page), 127 PAGE_SIZE, rx_complete, dev); 128 req->transfer_flags = 0; 129 err = usb_submit_urb(req, gfp_flags); 130 if (unlikely(err)) { 131 dev_dbg(&dev->dev, "RX submit error (%d)\n", err); 132 put_page(page); 133 } 134 return err; 135 } 136 137 static void rx_complete(struct urb *req) 138 { 139 struct net_device *dev = req->context; 140 struct usbpn_dev *pnd = netdev_priv(dev); 141 struct page *page = virt_to_page(req->transfer_buffer); 142 struct sk_buff *skb; 143 unsigned long flags; 144 int status = req->status; 145 146 switch (status) { 147 case 0: 148 spin_lock_irqsave(&pnd->rx_lock, flags); 149 skb = pnd->rx_skb; 150 if (!skb) { 151 skb = pnd->rx_skb = netdev_alloc_skb(dev, 12); 152 if (likely(skb)) { 153 /* Can't use pskb_pull() on page in IRQ */ 154 skb_put_data(skb, page_address(page), 1); 155 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, 156 page, 1, req->actual_length, 157 PAGE_SIZE); 158 page = NULL; 159 } 160 } else if (skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) { 161 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, 162 page, 0, req->actual_length, 163 PAGE_SIZE); 164 page = NULL; 165 } else { 166 dev_kfree_skb_any(skb); 167 pnd->rx_skb = NULL; 168 skb = NULL; 169 dev->stats.rx_length_errors++; 170 } 171 if (req->actual_length < PAGE_SIZE) 172 pnd->rx_skb = NULL; /* Last fragment */ 173 else 174 skb = NULL; 175 spin_unlock_irqrestore(&pnd->rx_lock, flags); 176 if (skb) { 177 skb->protocol = htons(ETH_P_PHONET); 178 skb_reset_mac_header(skb); 179 __skb_pull(skb, 1); 180 skb->dev = dev; 181 dev->stats.rx_packets++; 182 dev->stats.rx_bytes += skb->len; 183 184 netif_rx(skb); 185 } 186 goto resubmit; 187 188 case -ENOENT: 189 case -ECONNRESET: 190 case -ESHUTDOWN: 191 req = NULL; 192 break; 193 194 case -EOVERFLOW: 195 dev->stats.rx_over_errors++; 196 dev_dbg(&dev->dev, "RX overflow\n"); 197 break; 198 199 case -EILSEQ: 200 dev->stats.rx_crc_errors++; 201 break; 202 } 203 204 dev->stats.rx_errors++; 205 resubmit: 206 if (page) 207 put_page(page); 208 if (req) 209 rx_submit(pnd, req, GFP_ATOMIC); 210 } 211 212 static int usbpn_close(struct net_device *dev); 213 214 static int usbpn_open(struct net_device *dev) 215 { 216 struct usbpn_dev *pnd = netdev_priv(dev); 217 int err; 218 unsigned i; 219 unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber; 220 221 err = usb_set_interface(pnd->usb, num, pnd->active_setting); 222 if (err) 223 return err; 224 225 for (i = 0; i < rxq_size; i++) { 226 struct urb *req = usb_alloc_urb(0, GFP_KERNEL); 227 228 if (!req || rx_submit(pnd, req, GFP_KERNEL)) { 229 usb_free_urb(req); 230 usbpn_close(dev); 231 return -ENOMEM; 232 } 233 pnd->urbs[i] = req; 234 } 235 236 netif_wake_queue(dev); 237 return 0; 238 } 239 240 static int usbpn_close(struct net_device *dev) 241 { 242 struct usbpn_dev *pnd = netdev_priv(dev); 243 unsigned i; 244 unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber; 245 246 netif_stop_queue(dev); 247 248 for (i = 0; i < rxq_size; i++) { 249 struct urb *req = pnd->urbs[i]; 250 251 if (!req) 252 continue; 253 usb_kill_urb(req); 254 usb_free_urb(req); 255 pnd->urbs[i] = NULL; 256 } 257 258 return usb_set_interface(pnd->usb, num, !pnd->active_setting); 259 } 260 261 static int usbpn_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 262 void __user *data, int cmd) 263 { 264 struct if_phonet_req *req = (struct if_phonet_req *)ifr; 265 266 switch (cmd) { 267 case SIOCPNGAUTOCONF: 268 req->ifr_phonet_autoconf.device = PN_DEV_PC; 269 return 0; 270 } 271 return -ENOIOCTLCMD; 272 } 273 274 static const struct net_device_ops usbpn_ops = { 275 .ndo_open = usbpn_open, 276 .ndo_stop = usbpn_close, 277 .ndo_start_xmit = usbpn_xmit, 278 .ndo_siocdevprivate = usbpn_siocdevprivate, 279 }; 280 281 static void usbpn_setup(struct net_device *dev) 282 { 283 const u8 addr = PN_MEDIA_USB; 284 285 dev->features = 0; 286 dev->netdev_ops = &usbpn_ops; 287 dev->header_ops = &phonet_header_ops; 288 dev->type = ARPHRD_PHONET; 289 dev->flags = IFF_POINTOPOINT | IFF_NOARP; 290 dev->mtu = PHONET_MAX_MTU; 291 dev->min_mtu = PHONET_MIN_MTU; 292 dev->max_mtu = PHONET_MAX_MTU; 293 dev->hard_header_len = 1; 294 dev->addr_len = 1; 295 dev_addr_set(dev, &addr); 296 dev->tx_queue_len = 3; 297 298 dev->needs_free_netdev = true; 299 } 300 301 /* 302 * USB driver callbacks 303 */ 304 static const struct usb_device_id usbpn_ids[] = { 305 { 306 .match_flags = USB_DEVICE_ID_MATCH_VENDOR 307 | USB_DEVICE_ID_MATCH_INT_CLASS 308 | USB_DEVICE_ID_MATCH_INT_SUBCLASS, 309 .idVendor = 0x0421, /* Nokia */ 310 .bInterfaceClass = USB_CLASS_COMM, 311 .bInterfaceSubClass = 0xFE, 312 }, 313 { }, 314 }; 315 316 MODULE_DEVICE_TABLE(usb, usbpn_ids); 317 318 static struct usb_driver usbpn_driver; 319 320 static int usbpn_probe(struct usb_interface *intf, const struct usb_device_id *id) 321 { 322 static const char ifname[] = "usbpn%d"; 323 const struct usb_cdc_union_desc *union_header = NULL; 324 const struct usb_host_interface *data_desc; 325 struct usb_interface *data_intf; 326 struct usb_device *usbdev = interface_to_usbdev(intf); 327 struct net_device *dev; 328 struct usbpn_dev *pnd; 329 u8 *data; 330 int phonet = 0; 331 int len, err; 332 struct usb_cdc_parsed_header hdr; 333 334 data = intf->altsetting->extra; 335 len = intf->altsetting->extralen; 336 cdc_parse_cdc_header(&hdr, intf, data, len); 337 union_header = hdr.usb_cdc_union_desc; 338 phonet = hdr.phonet_magic_present; 339 340 if (!union_header || !phonet) 341 return -EINVAL; 342 343 data_intf = usb_ifnum_to_if(usbdev, union_header->bSlaveInterface0); 344 if (data_intf == NULL) 345 return -ENODEV; 346 /* Data interface has one inactive and one active setting */ 347 if (data_intf->num_altsetting != 2) 348 return -EINVAL; 349 if (data_intf->altsetting[0].desc.bNumEndpoints == 0 && 350 data_intf->altsetting[1].desc.bNumEndpoints == 2) 351 data_desc = data_intf->altsetting + 1; 352 else 353 if (data_intf->altsetting[0].desc.bNumEndpoints == 2 && 354 data_intf->altsetting[1].desc.bNumEndpoints == 0) 355 data_desc = data_intf->altsetting; 356 else 357 return -EINVAL; 358 359 dev = alloc_netdev(struct_size(pnd, urbs, rxq_size), ifname, 360 NET_NAME_UNKNOWN, usbpn_setup); 361 if (!dev) 362 return -ENOMEM; 363 364 pnd = netdev_priv(dev); 365 SET_NETDEV_DEV(dev, &intf->dev); 366 367 pnd->dev = dev; 368 pnd->usb = usbdev; 369 pnd->intf = intf; 370 pnd->data_intf = data_intf; 371 spin_lock_init(&pnd->tx_lock); 372 spin_lock_init(&pnd->rx_lock); 373 /* Endpoints */ 374 if (usb_pipein(data_desc->endpoint[0].desc.bEndpointAddress)) { 375 pnd->rx_pipe = usb_rcvbulkpipe(usbdev, 376 data_desc->endpoint[0].desc.bEndpointAddress); 377 pnd->tx_pipe = usb_sndbulkpipe(usbdev, 378 data_desc->endpoint[1].desc.bEndpointAddress); 379 } else { 380 pnd->rx_pipe = usb_rcvbulkpipe(usbdev, 381 data_desc->endpoint[1].desc.bEndpointAddress); 382 pnd->tx_pipe = usb_sndbulkpipe(usbdev, 383 data_desc->endpoint[0].desc.bEndpointAddress); 384 } 385 pnd->active_setting = data_desc - data_intf->altsetting; 386 387 err = usb_driver_claim_interface(&usbpn_driver, data_intf, pnd); 388 if (err) 389 goto out; 390 391 /* Force inactive mode until the network device is brought UP */ 392 usb_set_interface(usbdev, union_header->bSlaveInterface0, 393 !pnd->active_setting); 394 usb_set_intfdata(intf, pnd); 395 396 err = register_netdev(dev); 397 if (err) { 398 /* Set disconnected flag so that disconnect() returns early. */ 399 pnd->disconnected = 1; 400 usb_driver_release_interface(&usbpn_driver, data_intf); 401 goto out; 402 } 403 404 dev_dbg(&dev->dev, "USB CDC Phonet device found\n"); 405 return 0; 406 407 out: 408 usb_set_intfdata(intf, NULL); 409 free_netdev(dev); 410 return err; 411 } 412 413 static void usbpn_disconnect(struct usb_interface *intf) 414 { 415 struct usbpn_dev *pnd = usb_get_intfdata(intf); 416 417 if (pnd->disconnected) 418 return; 419 420 pnd->disconnected = 1; 421 usb_driver_release_interface(&usbpn_driver, 422 (pnd->intf == intf) ? pnd->data_intf : pnd->intf); 423 unregister_netdev(pnd->dev); 424 } 425 426 static struct usb_driver usbpn_driver = { 427 .name = "cdc_phonet", 428 .probe = usbpn_probe, 429 .disconnect = usbpn_disconnect, 430 .id_table = usbpn_ids, 431 .disable_hub_initiated_lpm = 1, 432 }; 433 434 module_usb_driver(usbpn_driver); 435 436 MODULE_AUTHOR("Remi Denis-Courmont"); 437 MODULE_DESCRIPTION("USB CDC Phonet host interface"); 438 MODULE_LICENSE("GPL"); 439