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 { 161 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, 162 page, 0, req->actual_length, 163 PAGE_SIZE); 164 page = NULL; 165 } 166 if (req->actual_length < PAGE_SIZE) 167 pnd->rx_skb = NULL; /* Last fragment */ 168 else 169 skb = NULL; 170 spin_unlock_irqrestore(&pnd->rx_lock, flags); 171 if (skb) { 172 skb->protocol = htons(ETH_P_PHONET); 173 skb_reset_mac_header(skb); 174 __skb_pull(skb, 1); 175 skb->dev = dev; 176 dev->stats.rx_packets++; 177 dev->stats.rx_bytes += skb->len; 178 179 netif_rx(skb); 180 } 181 goto resubmit; 182 183 case -ENOENT: 184 case -ECONNRESET: 185 case -ESHUTDOWN: 186 req = NULL; 187 break; 188 189 case -EOVERFLOW: 190 dev->stats.rx_over_errors++; 191 dev_dbg(&dev->dev, "RX overflow\n"); 192 break; 193 194 case -EILSEQ: 195 dev->stats.rx_crc_errors++; 196 break; 197 } 198 199 dev->stats.rx_errors++; 200 resubmit: 201 if (page) 202 put_page(page); 203 if (req) 204 rx_submit(pnd, req, GFP_ATOMIC); 205 } 206 207 static int usbpn_close(struct net_device *dev); 208 209 static int usbpn_open(struct net_device *dev) 210 { 211 struct usbpn_dev *pnd = netdev_priv(dev); 212 int err; 213 unsigned i; 214 unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber; 215 216 err = usb_set_interface(pnd->usb, num, pnd->active_setting); 217 if (err) 218 return err; 219 220 for (i = 0; i < rxq_size; i++) { 221 struct urb *req = usb_alloc_urb(0, GFP_KERNEL); 222 223 if (!req || rx_submit(pnd, req, GFP_KERNEL)) { 224 usb_free_urb(req); 225 usbpn_close(dev); 226 return -ENOMEM; 227 } 228 pnd->urbs[i] = req; 229 } 230 231 netif_wake_queue(dev); 232 return 0; 233 } 234 235 static int usbpn_close(struct net_device *dev) 236 { 237 struct usbpn_dev *pnd = netdev_priv(dev); 238 unsigned i; 239 unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber; 240 241 netif_stop_queue(dev); 242 243 for (i = 0; i < rxq_size; i++) { 244 struct urb *req = pnd->urbs[i]; 245 246 if (!req) 247 continue; 248 usb_kill_urb(req); 249 usb_free_urb(req); 250 pnd->urbs[i] = NULL; 251 } 252 253 return usb_set_interface(pnd->usb, num, !pnd->active_setting); 254 } 255 256 static int usbpn_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 257 void __user *data, int cmd) 258 { 259 struct if_phonet_req *req = (struct if_phonet_req *)ifr; 260 261 switch (cmd) { 262 case SIOCPNGAUTOCONF: 263 req->ifr_phonet_autoconf.device = PN_DEV_PC; 264 return 0; 265 } 266 return -ENOIOCTLCMD; 267 } 268 269 static const struct net_device_ops usbpn_ops = { 270 .ndo_open = usbpn_open, 271 .ndo_stop = usbpn_close, 272 .ndo_start_xmit = usbpn_xmit, 273 .ndo_siocdevprivate = usbpn_siocdevprivate, 274 }; 275 276 static void usbpn_setup(struct net_device *dev) 277 { 278 const u8 addr = PN_MEDIA_USB; 279 280 dev->features = 0; 281 dev->netdev_ops = &usbpn_ops; 282 dev->header_ops = &phonet_header_ops; 283 dev->type = ARPHRD_PHONET; 284 dev->flags = IFF_POINTOPOINT | IFF_NOARP; 285 dev->mtu = PHONET_MAX_MTU; 286 dev->min_mtu = PHONET_MIN_MTU; 287 dev->max_mtu = PHONET_MAX_MTU; 288 dev->hard_header_len = 1; 289 dev->addr_len = 1; 290 dev_addr_set(dev, &addr); 291 dev->tx_queue_len = 3; 292 293 dev->needs_free_netdev = true; 294 } 295 296 /* 297 * USB driver callbacks 298 */ 299 static const struct usb_device_id usbpn_ids[] = { 300 { 301 .match_flags = USB_DEVICE_ID_MATCH_VENDOR 302 | USB_DEVICE_ID_MATCH_INT_CLASS 303 | USB_DEVICE_ID_MATCH_INT_SUBCLASS, 304 .idVendor = 0x0421, /* Nokia */ 305 .bInterfaceClass = USB_CLASS_COMM, 306 .bInterfaceSubClass = 0xFE, 307 }, 308 { }, 309 }; 310 311 MODULE_DEVICE_TABLE(usb, usbpn_ids); 312 313 static struct usb_driver usbpn_driver; 314 315 static int usbpn_probe(struct usb_interface *intf, const struct usb_device_id *id) 316 { 317 static const char ifname[] = "usbpn%d"; 318 const struct usb_cdc_union_desc *union_header = NULL; 319 const struct usb_host_interface *data_desc; 320 struct usb_interface *data_intf; 321 struct usb_device *usbdev = interface_to_usbdev(intf); 322 struct net_device *dev; 323 struct usbpn_dev *pnd; 324 u8 *data; 325 int phonet = 0; 326 int len, err; 327 struct usb_cdc_parsed_header hdr; 328 329 data = intf->altsetting->extra; 330 len = intf->altsetting->extralen; 331 cdc_parse_cdc_header(&hdr, intf, data, len); 332 union_header = hdr.usb_cdc_union_desc; 333 phonet = hdr.phonet_magic_present; 334 335 if (!union_header || !phonet) 336 return -EINVAL; 337 338 data_intf = usb_ifnum_to_if(usbdev, union_header->bSlaveInterface0); 339 if (data_intf == NULL) 340 return -ENODEV; 341 /* Data interface has one inactive and one active setting */ 342 if (data_intf->num_altsetting != 2) 343 return -EINVAL; 344 if (data_intf->altsetting[0].desc.bNumEndpoints == 0 && 345 data_intf->altsetting[1].desc.bNumEndpoints == 2) 346 data_desc = data_intf->altsetting + 1; 347 else 348 if (data_intf->altsetting[0].desc.bNumEndpoints == 2 && 349 data_intf->altsetting[1].desc.bNumEndpoints == 0) 350 data_desc = data_intf->altsetting; 351 else 352 return -EINVAL; 353 354 dev = alloc_netdev(struct_size(pnd, urbs, rxq_size), ifname, 355 NET_NAME_UNKNOWN, usbpn_setup); 356 if (!dev) 357 return -ENOMEM; 358 359 pnd = netdev_priv(dev); 360 SET_NETDEV_DEV(dev, &intf->dev); 361 362 pnd->dev = dev; 363 pnd->usb = usbdev; 364 pnd->intf = intf; 365 pnd->data_intf = data_intf; 366 spin_lock_init(&pnd->tx_lock); 367 spin_lock_init(&pnd->rx_lock); 368 /* Endpoints */ 369 if (usb_pipein(data_desc->endpoint[0].desc.bEndpointAddress)) { 370 pnd->rx_pipe = usb_rcvbulkpipe(usbdev, 371 data_desc->endpoint[0].desc.bEndpointAddress); 372 pnd->tx_pipe = usb_sndbulkpipe(usbdev, 373 data_desc->endpoint[1].desc.bEndpointAddress); 374 } else { 375 pnd->rx_pipe = usb_rcvbulkpipe(usbdev, 376 data_desc->endpoint[1].desc.bEndpointAddress); 377 pnd->tx_pipe = usb_sndbulkpipe(usbdev, 378 data_desc->endpoint[0].desc.bEndpointAddress); 379 } 380 pnd->active_setting = data_desc - data_intf->altsetting; 381 382 err = usb_driver_claim_interface(&usbpn_driver, data_intf, pnd); 383 if (err) 384 goto out; 385 386 /* Force inactive mode until the network device is brought UP */ 387 usb_set_interface(usbdev, union_header->bSlaveInterface0, 388 !pnd->active_setting); 389 usb_set_intfdata(intf, pnd); 390 391 err = register_netdev(dev); 392 if (err) { 393 /* Set disconnected flag so that disconnect() returns early. */ 394 pnd->disconnected = 1; 395 usb_driver_release_interface(&usbpn_driver, data_intf); 396 goto out; 397 } 398 399 dev_dbg(&dev->dev, "USB CDC Phonet device found\n"); 400 return 0; 401 402 out: 403 usb_set_intfdata(intf, NULL); 404 free_netdev(dev); 405 return err; 406 } 407 408 static void usbpn_disconnect(struct usb_interface *intf) 409 { 410 struct usbpn_dev *pnd = usb_get_intfdata(intf); 411 412 if (pnd->disconnected) 413 return; 414 415 pnd->disconnected = 1; 416 usb_driver_release_interface(&usbpn_driver, 417 (pnd->intf == intf) ? pnd->data_intf : pnd->intf); 418 unregister_netdev(pnd->dev); 419 } 420 421 static struct usb_driver usbpn_driver = { 422 .name = "cdc_phonet", 423 .probe = usbpn_probe, 424 .disconnect = usbpn_disconnect, 425 .id_table = usbpn_ids, 426 .disable_hub_initiated_lpm = 1, 427 }; 428 429 module_usb_driver(usbpn_driver); 430 431 MODULE_AUTHOR("Remi Denis-Courmont"); 432 MODULE_DESCRIPTION("USB CDC Phonet host interface"); 433 MODULE_LICENSE("GPL"); 434