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
23static const unsigned rxq_size = 17;
24
25struct 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
42static void tx_complete(struct urb *req);
43static void rx_complete(struct urb *req);
44
45/*
46 * Network device callbacks
47 */
48static 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(iso_packets: 0, GFP_ATOMIC);
59 if (!req)
60 goto drop;
61 usb_fill_bulk_urb(urb: req, dev: pnd->usb, pipe: pnd->tx_pipe, transfer_buffer: skb->data, buffer_length: skb->len,
62 complete_fn: tx_complete, context: skb);
63 req->transfer_flags = URB_ZERO_PACKET;
64 err = usb_submit_urb(urb: req, GFP_ATOMIC);
65 if (err) {
66 usb_free_urb(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(lock: &pnd->tx_lock, flags);
75 return NETDEV_TX_OK;
76
77drop:
78 dev_kfree_skb(skb);
79 dev->stats.tx_dropped++;
80 return NETDEV_TX_OK;
81}
82
83static 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(lock: &pnd->tx_lock, flags);
111
112 dev_kfree_skb_any(skb);
113 usb_free_urb(urb: req);
114}
115
116static 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_mask: gfp_flags | __GFP_NOMEMALLOC);
123 if (!page)
124 return -ENOMEM;
125
126 usb_fill_bulk_urb(urb: req, dev: pnd->usb, pipe: pnd->rx_pipe, page_address(page),
127 PAGE_SIZE, complete_fn: rx_complete, context: dev);
128 req->transfer_flags = 0;
129 err = usb_submit_urb(urb: req, mem_flags: 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
137static 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, length: 12);
152 if (likely(skb)) {
153 /* Can't use pskb_pull() on page in IRQ */
154 skb_put_data(skb, page_address(page), len: 1);
155 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
156 page, off: 1, size: 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, off: 0, size: 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(lock: &pnd->rx_lock, flags);
171 if (skb) {
172 skb->protocol = htons(ETH_P_PHONET);
173 skb_reset_mac_header(skb);
174 __skb_pull(skb, len: 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++;
200resubmit:
201 if (page)
202 put_page(page);
203 if (req)
204 rx_submit(pnd, req, GFP_ATOMIC);
205}
206
207static int usbpn_close(struct net_device *dev);
208
209static 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(dev: pnd->usb, ifnum: num, alternate: 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(iso_packets: 0, GFP_KERNEL);
222
223 if (!req || rx_submit(pnd, req, GFP_KERNEL)) {
224 usb_free_urb(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
235static 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(urb: req);
249 usb_free_urb(urb: req);
250 pnd->urbs[i] = NULL;
251 }
252
253 return usb_set_interface(dev: pnd->usb, ifnum: num, alternate: !pnd->active_setting);
254}
255
256static 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
269static 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
276static 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: &addr);
291 dev->tx_queue_len = 3;
292
293 dev->needs_free_netdev = true;
294}
295
296/*
297 * USB driver callbacks
298 */
299static 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
311MODULE_DEVICE_TABLE(usb, usbpn_ids);
312
313static struct usb_driver usbpn_driver;
314
315static 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: &hdr, intf, buffer: data, buflen: 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(dev: usbdev, ifnum: 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(driver: &usbpn_driver, iface: data_intf, data: pnd);
383 if (err)
384 goto out;
385
386 /* Force inactive mode until the network device is brought UP */
387 usb_set_interface(dev: usbdev, ifnum: union_header->bSlaveInterface0,
388 alternate: !pnd->active_setting);
389 usb_set_intfdata(intf, data: 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(driver: &usbpn_driver, iface: data_intf);
396 goto out;
397 }
398
399 dev_dbg(&dev->dev, "USB CDC Phonet device found\n");
400 return 0;
401
402out:
403 usb_set_intfdata(intf, NULL);
404 free_netdev(dev);
405 return err;
406}
407
408static 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(driver: &usbpn_driver,
417 iface: (pnd->intf == intf) ? pnd->data_intf : pnd->intf);
418 unregister_netdev(dev: pnd->dev);
419}
420
421static 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
429module_usb_driver(usbpn_driver);
430
431MODULE_AUTHOR("Remi Denis-Courmont");
432MODULE_DESCRIPTION("USB CDC Phonet host interface");
433MODULE_LICENSE("GPL");
434

source code of linux/drivers/net/usb/cdc-phonet.c