xref: /openbmc/linux/drivers/net/usb/cdc_mbim.c (revision f7777dcc)
1 /*
2  * Copyright (c) 2012  Smith Micro Software, Inc.
3  * Copyright (c) 2012  Bjørn Mork <bjorn@mork.no>
4  *
5  * This driver is based on and reuse most of cdc_ncm, which is
6  * Copyright (C) ST-Ericsson 2010-2012
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/netdevice.h>
15 #include <linux/ethtool.h>
16 #include <linux/if_vlan.h>
17 #include <linux/ip.h>
18 #include <linux/mii.h>
19 #include <linux/usb.h>
20 #include <linux/usb/cdc.h>
21 #include <linux/usb/usbnet.h>
22 #include <linux/usb/cdc-wdm.h>
23 #include <linux/usb/cdc_ncm.h>
24 
25 /* driver specific data - must match cdc_ncm usage */
26 struct cdc_mbim_state {
27 	struct cdc_ncm_ctx *ctx;
28 	atomic_t pmcount;
29 	struct usb_driver *subdriver;
30 	struct usb_interface *control;
31 	struct usb_interface *data;
32 };
33 
34 /* using a counter to merge subdriver requests with our own into a combined state */
35 static int cdc_mbim_manage_power(struct usbnet *dev, int on)
36 {
37 	struct cdc_mbim_state *info = (void *)&dev->data;
38 	int rv = 0;
39 
40 	dev_dbg(&dev->intf->dev, "%s() pmcount=%d, on=%d\n", __func__, atomic_read(&info->pmcount), on);
41 
42 	if ((on && atomic_add_return(1, &info->pmcount) == 1) || (!on && atomic_dec_and_test(&info->pmcount))) {
43 		/* need autopm_get/put here to ensure the usbcore sees the new value */
44 		rv = usb_autopm_get_interface(dev->intf);
45 		if (rv < 0)
46 			goto err;
47 		dev->intf->needs_remote_wakeup = on;
48 		usb_autopm_put_interface(dev->intf);
49 	}
50 err:
51 	return rv;
52 }
53 
54 static int cdc_mbim_wdm_manage_power(struct usb_interface *intf, int status)
55 {
56 	struct usbnet *dev = usb_get_intfdata(intf);
57 
58 	/* can be called while disconnecting */
59 	if (!dev)
60 		return 0;
61 
62 	return cdc_mbim_manage_power(dev, status);
63 }
64 
65 
66 static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
67 {
68 	struct cdc_ncm_ctx *ctx;
69 	struct usb_driver *subdriver = ERR_PTR(-ENODEV);
70 	int ret = -ENODEV;
71 	u8 data_altsetting = cdc_ncm_select_altsetting(dev, intf);
72 	struct cdc_mbim_state *info = (void *)&dev->data;
73 
74 	/* Probably NCM, defer for cdc_ncm_bind */
75 	if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
76 		goto err;
77 
78 	ret = cdc_ncm_bind_common(dev, intf, data_altsetting);
79 	if (ret)
80 		goto err;
81 
82 	ctx = info->ctx;
83 
84 	/* The MBIM descriptor and the status endpoint are required */
85 	if (ctx->mbim_desc && dev->status)
86 		subdriver = usb_cdc_wdm_register(ctx->control,
87 						 &dev->status->desc,
88 						 le16_to_cpu(ctx->mbim_desc->wMaxControlMessage),
89 						 cdc_mbim_wdm_manage_power);
90 	if (IS_ERR(subdriver)) {
91 		ret = PTR_ERR(subdriver);
92 		cdc_ncm_unbind(dev, intf);
93 		goto err;
94 	}
95 
96 	/* can't let usbnet use the interrupt endpoint */
97 	dev->status = NULL;
98 	info->subdriver = subdriver;
99 
100 	/* MBIM cannot do ARP */
101 	dev->net->flags |= IFF_NOARP;
102 
103 	/* no need to put the VLAN tci in the packet headers */
104 	dev->net->features |= NETIF_F_HW_VLAN_CTAG_TX;
105 err:
106 	return ret;
107 }
108 
109 static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
110 {
111 	struct cdc_mbim_state *info = (void *)&dev->data;
112 	struct cdc_ncm_ctx *ctx = info->ctx;
113 
114 	/* disconnect subdriver from control interface */
115 	if (info->subdriver && info->subdriver->disconnect)
116 		info->subdriver->disconnect(ctx->control);
117 	info->subdriver = NULL;
118 
119 	/* let NCM unbind clean up both control and data interface */
120 	cdc_ncm_unbind(dev, intf);
121 }
122 
123 
124 static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
125 {
126 	struct sk_buff *skb_out;
127 	struct cdc_mbim_state *info = (void *)&dev->data;
128 	struct cdc_ncm_ctx *ctx = info->ctx;
129 	__le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
130 	u16 tci = 0;
131 	u8 *c;
132 
133 	if (!ctx)
134 		goto error;
135 
136 	if (skb) {
137 		if (skb->len <= ETH_HLEN)
138 			goto error;
139 
140 		/* mapping VLANs to MBIM sessions:
141 		 *   no tag     => IPS session <0>
142 		 *   1 - 255    => IPS session <vlanid>
143 		 *   256 - 511  => DSS session <vlanid - 256>
144 		 *   512 - 4095 => unsupported, drop
145 		 */
146 		vlan_get_tag(skb, &tci);
147 
148 		switch (tci & 0x0f00) {
149 		case 0x0000: /* VLAN ID 0 - 255 */
150 			/* verify that datagram is IPv4 or IPv6 */
151 			skb_reset_mac_header(skb);
152 			switch (eth_hdr(skb)->h_proto) {
153 			case htons(ETH_P_IP):
154 			case htons(ETH_P_IPV6):
155 				break;
156 			default:
157 				goto error;
158 			}
159 			c = (u8 *)&sign;
160 			c[3] = tci;
161 			break;
162 		case 0x0100: /* VLAN ID 256 - 511 */
163 			sign = cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN);
164 			c = (u8 *)&sign;
165 			c[3] = tci;
166 			break;
167 		default:
168 			netif_err(dev, tx_err, dev->net,
169 				  "unsupported tci=0x%04x\n", tci);
170 			goto error;
171 		}
172 		skb_pull(skb, ETH_HLEN);
173 	}
174 
175 	spin_lock_bh(&ctx->mtx);
176 	skb_out = cdc_ncm_fill_tx_frame(ctx, skb, sign);
177 	spin_unlock_bh(&ctx->mtx);
178 	return skb_out;
179 
180 error:
181 	if (skb)
182 		dev_kfree_skb_any(skb);
183 
184 	return NULL;
185 }
186 
187 static struct sk_buff *cdc_mbim_process_dgram(struct usbnet *dev, u8 *buf, size_t len, u16 tci)
188 {
189 	__be16 proto = htons(ETH_P_802_3);
190 	struct sk_buff *skb = NULL;
191 
192 	if (tci < 256) { /* IPS session? */
193 		if (len < sizeof(struct iphdr))
194 			goto err;
195 
196 		switch (*buf & 0xf0) {
197 		case 0x40:
198 			proto = htons(ETH_P_IP);
199 			break;
200 		case 0x60:
201 			proto = htons(ETH_P_IPV6);
202 			break;
203 		default:
204 			goto err;
205 		}
206 	}
207 
208 	skb = netdev_alloc_skb_ip_align(dev->net,  len + ETH_HLEN);
209 	if (!skb)
210 		goto err;
211 
212 	/* add an ethernet header */
213 	skb_put(skb, ETH_HLEN);
214 	skb_reset_mac_header(skb);
215 	eth_hdr(skb)->h_proto = proto;
216 	memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
217 	memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
218 
219 	/* add datagram */
220 	memcpy(skb_put(skb, len), buf, len);
221 
222 	/* map MBIM session to VLAN */
223 	if (tci)
224 		vlan_put_tag(skb, htons(ETH_P_8021Q), tci);
225 err:
226 	return skb;
227 }
228 
229 static int cdc_mbim_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
230 {
231 	struct sk_buff *skb;
232 	struct cdc_mbim_state *info = (void *)&dev->data;
233 	struct cdc_ncm_ctx *ctx = info->ctx;
234 	int len;
235 	int nframes;
236 	int x;
237 	int offset;
238 	struct usb_cdc_ncm_ndp16 *ndp16;
239 	struct usb_cdc_ncm_dpe16 *dpe16;
240 	int ndpoffset;
241 	int loopcount = 50; /* arbitrary max preventing infinite loop */
242 	u8 *c;
243 	u16 tci;
244 
245 	ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
246 	if (ndpoffset < 0)
247 		goto error;
248 
249 next_ndp:
250 	nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
251 	if (nframes < 0)
252 		goto error;
253 
254 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
255 
256 	switch (ndp16->dwSignature & cpu_to_le32(0x00ffffff)) {
257 	case cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN):
258 		c = (u8 *)&ndp16->dwSignature;
259 		tci = c[3];
260 		break;
261 	case cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN):
262 		c = (u8 *)&ndp16->dwSignature;
263 		tci = c[3] + 256;
264 		break;
265 	default:
266 		netif_dbg(dev, rx_err, dev->net,
267 			  "unsupported NDP signature <0x%08x>\n",
268 			  le32_to_cpu(ndp16->dwSignature));
269 		goto err_ndp;
270 
271 	}
272 
273 	dpe16 = ndp16->dpe16;
274 	for (x = 0; x < nframes; x++, dpe16++) {
275 		offset = le16_to_cpu(dpe16->wDatagramIndex);
276 		len = le16_to_cpu(dpe16->wDatagramLength);
277 
278 		/*
279 		 * CDC NCM ch. 3.7
280 		 * All entries after first NULL entry are to be ignored
281 		 */
282 		if ((offset == 0) || (len == 0)) {
283 			if (!x)
284 				goto err_ndp; /* empty NTB */
285 			break;
286 		}
287 
288 		/* sanity checking */
289 		if (((offset + len) > skb_in->len) || (len > ctx->rx_max)) {
290 			netif_dbg(dev, rx_err, dev->net,
291 				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
292 				  x, offset, len, skb_in);
293 			if (!x)
294 				goto err_ndp;
295 			break;
296 		} else {
297 			skb = cdc_mbim_process_dgram(dev, skb_in->data + offset, len, tci);
298 			if (!skb)
299 				goto error;
300 			usbnet_skb_return(dev, skb);
301 		}
302 	}
303 err_ndp:
304 	/* are there more NDPs to process? */
305 	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
306 	if (ndpoffset && loopcount--)
307 		goto next_ndp;
308 
309 	return 1;
310 error:
311 	return 0;
312 }
313 
314 static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message)
315 {
316 	int ret = 0;
317 	struct usbnet *dev = usb_get_intfdata(intf);
318 	struct cdc_mbim_state *info = (void *)&dev->data;
319 	struct cdc_ncm_ctx *ctx = info->ctx;
320 
321 	if (ctx == NULL) {
322 		ret = -1;
323 		goto error;
324 	}
325 
326 	/*
327 	 * Both usbnet_suspend() and subdriver->suspend() MUST return 0
328 	 * in system sleep context, otherwise, the resume callback has
329 	 * to recover device from previous suspend failure.
330 	 */
331 	ret = usbnet_suspend(intf, message);
332 	if (ret < 0)
333 		goto error;
334 
335 	if (intf == ctx->control && info->subdriver && info->subdriver->suspend)
336 		ret = info->subdriver->suspend(intf, message);
337 	if (ret < 0)
338 		usbnet_resume(intf);
339 
340 error:
341 	return ret;
342 }
343 
344 static int cdc_mbim_resume(struct usb_interface *intf)
345 {
346 	int  ret = 0;
347 	struct usbnet *dev = usb_get_intfdata(intf);
348 	struct cdc_mbim_state *info = (void *)&dev->data;
349 	struct cdc_ncm_ctx *ctx = info->ctx;
350 	bool callsub = (intf == ctx->control && info->subdriver && info->subdriver->resume);
351 
352 	if (callsub)
353 		ret = info->subdriver->resume(intf);
354 	if (ret < 0)
355 		goto err;
356 	ret = usbnet_resume(intf);
357 	if (ret < 0 && callsub && info->subdriver->suspend)
358 		info->subdriver->suspend(intf, PMSG_SUSPEND);
359 err:
360 	return ret;
361 }
362 
363 static const struct driver_info cdc_mbim_info = {
364 	.description = "CDC MBIM",
365 	.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
366 	.bind = cdc_mbim_bind,
367 	.unbind = cdc_mbim_unbind,
368 	.manage_power = cdc_mbim_manage_power,
369 	.rx_fixup = cdc_mbim_rx_fixup,
370 	.tx_fixup = cdc_mbim_tx_fixup,
371 };
372 
373 /* MBIM and NCM devices should not need a ZLP after NTBs with
374  * dwNtbOutMaxSize length. This driver_info is for the exceptional
375  * devices requiring it anyway, allowing them to be supported without
376  * forcing the performance penalty on all the sane devices.
377  */
378 static const struct driver_info cdc_mbim_info_zlp = {
379 	.description = "CDC MBIM",
380 	.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP,
381 	.bind = cdc_mbim_bind,
382 	.unbind = cdc_mbim_unbind,
383 	.manage_power = cdc_mbim_manage_power,
384 	.rx_fixup = cdc_mbim_rx_fixup,
385 	.tx_fixup = cdc_mbim_tx_fixup,
386 };
387 
388 static const struct usb_device_id mbim_devs[] = {
389 	/* This duplicate NCM entry is intentional. MBIM devices can
390 	 * be disguised as NCM by default, and this is necessary to
391 	 * allow us to bind the correct driver_info to such devices.
392 	 *
393 	 * bind() will sort out this for us, selecting the correct
394 	 * entry and reject the other
395 	 */
396 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
397 	  .driver_info = (unsigned long)&cdc_mbim_info,
398 	},
399 	/* Sierra Wireless MC7710 need ZLPs */
400 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x68a2, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
401 	  .driver_info = (unsigned long)&cdc_mbim_info_zlp,
402 	},
403 	/* HP hs2434 Mobile Broadband Module needs ZLPs */
404 	{ USB_DEVICE_AND_INTERFACE_INFO(0x3f0, 0x4b1d, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
405 	  .driver_info = (unsigned long)&cdc_mbim_info_zlp,
406 	},
407 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
408 	  .driver_info = (unsigned long)&cdc_mbim_info,
409 	},
410 	{
411 	},
412 };
413 MODULE_DEVICE_TABLE(usb, mbim_devs);
414 
415 static struct usb_driver cdc_mbim_driver = {
416 	.name = "cdc_mbim",
417 	.id_table = mbim_devs,
418 	.probe = usbnet_probe,
419 	.disconnect = usbnet_disconnect,
420 	.suspend = cdc_mbim_suspend,
421 	.resume = cdc_mbim_resume,
422 	.reset_resume =	cdc_mbim_resume,
423 	.supports_autosuspend = 1,
424 	.disable_hub_initiated_lpm = 1,
425 };
426 module_usb_driver(cdc_mbim_driver);
427 
428 MODULE_AUTHOR("Greg Suarez <gsuarez@smithmicro.com>");
429 MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
430 MODULE_DESCRIPTION("USB CDC MBIM host driver");
431 MODULE_LICENSE("GPL");
432