1 /*
2 * f_obex.c -- USB CDC OBEX function driver
3 *
4 * Copyright (C) 2008 Nokia Corporation
5 * Contact: Felipe Balbi <felipe.balbi@nokia.com>
6 *
7 * Based on f_acm.c by Al Borchers and David Brownell.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 */
14
15 /* #define VERBOSE_DEBUG */
16
17 #include <linux/slab.h>
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/module.h>
21
22 #include "u_serial.h"
23 #include "gadget_chips.h"
24
25
26 /*
27 * This CDC OBEX function support just packages a TTY-ish byte stream.
28 * A user mode server will put it into "raw" mode and handle all the
29 * relevant protocol details ... this is just a kernel passthrough.
30 * When possible, we prevent gadget enumeration until that server is
31 * ready to handle the commands.
32 */
33
34 struct f_obex {
35 struct gserial port;
36 u8 ctrl_id;
37 u8 data_id;
38 u8 port_num;
39 u8 can_activate;
40 };
41
func_to_obex(struct usb_function * f)42 static inline struct f_obex *func_to_obex(struct usb_function *f)
43 {
44 return container_of(f, struct f_obex, port.func);
45 }
46
port_to_obex(struct gserial * p)47 static inline struct f_obex *port_to_obex(struct gserial *p)
48 {
49 return container_of(p, struct f_obex, port);
50 }
51
52 /*-------------------------------------------------------------------------*/
53
54 #define OBEX_CTRL_IDX 0
55 #define OBEX_DATA_IDX 1
56
57 static struct usb_string obex_string_defs[] = {
58 [OBEX_CTRL_IDX].s = "CDC Object Exchange (OBEX)",
59 [OBEX_DATA_IDX].s = "CDC OBEX Data",
60 { }, /* end of list */
61 };
62
63 static struct usb_gadget_strings obex_string_table = {
64 .language = 0x0409, /* en-US */
65 .strings = obex_string_defs,
66 };
67
68 static struct usb_gadget_strings *obex_strings[] = {
69 &obex_string_table,
70 NULL,
71 };
72
73 /*-------------------------------------------------------------------------*/
74
75 static struct usb_interface_descriptor obex_control_intf __initdata = {
76 .bLength = sizeof(obex_control_intf),
77 .bDescriptorType = USB_DT_INTERFACE,
78 .bInterfaceNumber = 0,
79
80 .bAlternateSetting = 0,
81 .bNumEndpoints = 0,
82 .bInterfaceClass = USB_CLASS_COMM,
83 .bInterfaceSubClass = USB_CDC_SUBCLASS_OBEX,
84 };
85
86 static struct usb_interface_descriptor obex_data_nop_intf __initdata = {
87 .bLength = sizeof(obex_data_nop_intf),
88 .bDescriptorType = USB_DT_INTERFACE,
89 .bInterfaceNumber = 1,
90
91 .bAlternateSetting = 0,
92 .bNumEndpoints = 0,
93 .bInterfaceClass = USB_CLASS_CDC_DATA,
94 };
95
96 static struct usb_interface_descriptor obex_data_intf __initdata = {
97 .bLength = sizeof(obex_data_intf),
98 .bDescriptorType = USB_DT_INTERFACE,
99 .bInterfaceNumber = 2,
100
101 .bAlternateSetting = 1,
102 .bNumEndpoints = 2,
103 .bInterfaceClass = USB_CLASS_CDC_DATA,
104 };
105
106 static struct usb_cdc_header_desc obex_cdc_header_desc __initdata = {
107 .bLength = sizeof(obex_cdc_header_desc),
108 .bDescriptorType = USB_DT_CS_INTERFACE,
109 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
110 .bcdCDC = cpu_to_le16(0x0120),
111 };
112
113 static struct usb_cdc_union_desc obex_cdc_union_desc __initdata = {
114 .bLength = sizeof(obex_cdc_union_desc),
115 .bDescriptorType = USB_DT_CS_INTERFACE,
116 .bDescriptorSubType = USB_CDC_UNION_TYPE,
117 .bMasterInterface0 = 1,
118 .bSlaveInterface0 = 2,
119 };
120
121 static struct usb_cdc_obex_desc obex_desc __initdata = {
122 .bLength = sizeof(obex_desc),
123 .bDescriptorType = USB_DT_CS_INTERFACE,
124 .bDescriptorSubType = USB_CDC_OBEX_TYPE,
125 .bcdVersion = cpu_to_le16(0x0100),
126 };
127
128 /* High-Speed Support */
129
130 static struct usb_endpoint_descriptor obex_hs_ep_out_desc __initdata = {
131 .bLength = USB_DT_ENDPOINT_SIZE,
132 .bDescriptorType = USB_DT_ENDPOINT,
133
134 .bEndpointAddress = USB_DIR_OUT,
135 .bmAttributes = USB_ENDPOINT_XFER_BULK,
136 .wMaxPacketSize = cpu_to_le16(512),
137 };
138
139 static struct usb_endpoint_descriptor obex_hs_ep_in_desc __initdata = {
140 .bLength = USB_DT_ENDPOINT_SIZE,
141 .bDescriptorType = USB_DT_ENDPOINT,
142
143 .bEndpointAddress = USB_DIR_IN,
144 .bmAttributes = USB_ENDPOINT_XFER_BULK,
145 .wMaxPacketSize = cpu_to_le16(512),
146 };
147
148 static struct usb_descriptor_header *hs_function[] __initdata = {
149 (struct usb_descriptor_header *) &obex_control_intf,
150 (struct usb_descriptor_header *) &obex_cdc_header_desc,
151 (struct usb_descriptor_header *) &obex_desc,
152 (struct usb_descriptor_header *) &obex_cdc_union_desc,
153
154 (struct usb_descriptor_header *) &obex_data_nop_intf,
155 (struct usb_descriptor_header *) &obex_data_intf,
156 (struct usb_descriptor_header *) &obex_hs_ep_in_desc,
157 (struct usb_descriptor_header *) &obex_hs_ep_out_desc,
158 NULL,
159 };
160
161 /* Full-Speed Support */
162
163 static struct usb_endpoint_descriptor obex_fs_ep_in_desc __initdata = {
164 .bLength = USB_DT_ENDPOINT_SIZE,
165 .bDescriptorType = USB_DT_ENDPOINT,
166
167 .bEndpointAddress = USB_DIR_IN,
168 .bmAttributes = USB_ENDPOINT_XFER_BULK,
169 };
170
171 static struct usb_endpoint_descriptor obex_fs_ep_out_desc __initdata = {
172 .bLength = USB_DT_ENDPOINT_SIZE,
173 .bDescriptorType = USB_DT_ENDPOINT,
174
175 .bEndpointAddress = USB_DIR_OUT,
176 .bmAttributes = USB_ENDPOINT_XFER_BULK,
177 };
178
179 static struct usb_descriptor_header *fs_function[] __initdata = {
180 (struct usb_descriptor_header *) &obex_control_intf,
181 (struct usb_descriptor_header *) &obex_cdc_header_desc,
182 (struct usb_descriptor_header *) &obex_desc,
183 (struct usb_descriptor_header *) &obex_cdc_union_desc,
184
185 (struct usb_descriptor_header *) &obex_data_nop_intf,
186 (struct usb_descriptor_header *) &obex_data_intf,
187 (struct usb_descriptor_header *) &obex_fs_ep_in_desc,
188 (struct usb_descriptor_header *) &obex_fs_ep_out_desc,
189 NULL,
190 };
191
192 /*-------------------------------------------------------------------------*/
193
obex_set_alt(struct usb_function * f,unsigned intf,unsigned alt)194 static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
195 {
196 struct f_obex *obex = func_to_obex(f);
197 struct usb_composite_dev *cdev = f->config->cdev;
198
199 if (intf == obex->ctrl_id) {
200 if (alt != 0)
201 goto fail;
202 /* NOP */
203 DBG(cdev, "reset obex ttyGS%d control\n", obex->port_num);
204
205 } else if (intf == obex->data_id) {
206 if (alt > 1)
207 goto fail;
208
209 if (obex->port.in->driver_data) {
210 DBG(cdev, "reset obex ttyGS%d\n", obex->port_num);
211 gserial_disconnect(&obex->port);
212 }
213
214 if (!obex->port.in->desc || !obex->port.out->desc) {
215 DBG(cdev, "init obex ttyGS%d\n", obex->port_num);
216 if (config_ep_by_speed(cdev->gadget, f,
217 obex->port.in) ||
218 config_ep_by_speed(cdev->gadget, f,
219 obex->port.out)) {
220 obex->port.out->desc = NULL;
221 obex->port.in->desc = NULL;
222 goto fail;
223 }
224 }
225
226 if (alt == 1) {
227 DBG(cdev, "activate obex ttyGS%d\n", obex->port_num);
228 gserial_connect(&obex->port, obex->port_num);
229 }
230
231 } else
232 goto fail;
233
234 return 0;
235
236 fail:
237 return -EINVAL;
238 }
239
obex_get_alt(struct usb_function * f,unsigned intf)240 static int obex_get_alt(struct usb_function *f, unsigned intf)
241 {
242 struct f_obex *obex = func_to_obex(f);
243
244 if (intf == obex->ctrl_id)
245 return 0;
246
247 return obex->port.in->driver_data ? 1 : 0;
248 }
249
obex_disable(struct usb_function * f)250 static void obex_disable(struct usb_function *f)
251 {
252 struct f_obex *obex = func_to_obex(f);
253 struct usb_composite_dev *cdev = f->config->cdev;
254
255 DBG(cdev, "obex ttyGS%d disable\n", obex->port_num);
256 gserial_disconnect(&obex->port);
257 }
258
259 /*-------------------------------------------------------------------------*/
260
obex_connect(struct gserial * g)261 static void obex_connect(struct gserial *g)
262 {
263 struct f_obex *obex = port_to_obex(g);
264 struct usb_composite_dev *cdev = g->func.config->cdev;
265 int status;
266
267 if (!obex->can_activate)
268 return;
269
270 status = usb_function_activate(&g->func);
271 if (status)
272 DBG(cdev, "obex ttyGS%d function activate --> %d\n",
273 obex->port_num, status);
274 }
275
obex_disconnect(struct gserial * g)276 static void obex_disconnect(struct gserial *g)
277 {
278 struct f_obex *obex = port_to_obex(g);
279 struct usb_composite_dev *cdev = g->func.config->cdev;
280 int status;
281
282 if (!obex->can_activate)
283 return;
284
285 status = usb_function_deactivate(&g->func);
286 if (status)
287 DBG(cdev, "obex ttyGS%d function deactivate --> %d\n",
288 obex->port_num, status);
289 }
290
291 /*-------------------------------------------------------------------------*/
292
293 static int __init
obex_bind(struct usb_configuration * c,struct usb_function * f)294 obex_bind(struct usb_configuration *c, struct usb_function *f)
295 {
296 struct usb_composite_dev *cdev = c->cdev;
297 struct f_obex *obex = func_to_obex(f);
298 int status;
299 struct usb_ep *ep;
300
301 /* allocate instance-specific interface IDs, and patch descriptors */
302
303 status = usb_interface_id(c, f);
304 if (status < 0)
305 goto fail;
306 obex->ctrl_id = status;
307
308 obex_control_intf.bInterfaceNumber = status;
309 obex_cdc_union_desc.bMasterInterface0 = status;
310
311 status = usb_interface_id(c, f);
312 if (status < 0)
313 goto fail;
314 obex->data_id = status;
315
316 obex_data_nop_intf.bInterfaceNumber = status;
317 obex_data_intf.bInterfaceNumber = status;
318 obex_cdc_union_desc.bSlaveInterface0 = status;
319
320 /* allocate instance-specific endpoints */
321
322 ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
323 if (!ep)
324 goto fail;
325 obex->port.in = ep;
326 ep->driver_data = cdev; /* claim */
327
328 ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
329 if (!ep)
330 goto fail;
331 obex->port.out = ep;
332 ep->driver_data = cdev; /* claim */
333
334 /* copy descriptors, and track endpoint copies */
335 f->descriptors = usb_copy_descriptors(fs_function);
336
337 /* support all relevant hardware speeds... we expect that when
338 * hardware is dual speed, all bulk-capable endpoints work at
339 * both speeds
340 */
341 if (gadget_is_dualspeed(c->cdev->gadget)) {
342
343 obex_hs_ep_in_desc.bEndpointAddress =
344 obex_fs_ep_in_desc.bEndpointAddress;
345 obex_hs_ep_out_desc.bEndpointAddress =
346 obex_fs_ep_out_desc.bEndpointAddress;
347
348 /* copy descriptors, and track endpoint copies */
349 f->hs_descriptors = usb_copy_descriptors(hs_function);
350 }
351
352 /* Avoid letting this gadget enumerate until the userspace
353 * OBEX server is active.
354 */
355 status = usb_function_deactivate(f);
356 if (status < 0)
357 WARNING(cdev, "obex ttyGS%d: can't prevent enumeration, %d\n",
358 obex->port_num, status);
359 else
360 obex->can_activate = true;
361
362
363 DBG(cdev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
364 obex->port_num,
365 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
366 obex->port.in->name, obex->port.out->name);
367
368 return 0;
369
370 fail:
371 /* we might as well release our claims on endpoints */
372 if (obex->port.out)
373 obex->port.out->driver_data = NULL;
374 if (obex->port.in)
375 obex->port.in->driver_data = NULL;
376
377 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
378
379 return status;
380 }
381
382 static void
obex_unbind(struct usb_configuration * c,struct usb_function * f)383 obex_unbind(struct usb_configuration *c, struct usb_function *f)
384 {
385 if (gadget_is_dualspeed(c->cdev->gadget))
386 usb_free_descriptors(f->hs_descriptors);
387 usb_free_descriptors(f->descriptors);
388 kfree(func_to_obex(f));
389 }
390
391 /* Some controllers can't support CDC OBEX ... */
can_support_obex(struct usb_configuration * c)392 static inline bool can_support_obex(struct usb_configuration *c)
393 {
394 /* Since the first interface is a NOP, we can ignore the
395 * issue of multi-interface support on most controllers.
396 *
397 * Altsettings are mandatory, however...
398 */
399 if (!gadget_supports_altsettings(c->cdev->gadget))
400 return false;
401
402 /* everything else is *probably* fine ... */
403 return true;
404 }
405
406 /**
407 * obex_bind_config - add a CDC OBEX function to a configuration
408 * @c: the configuration to support the CDC OBEX instance
409 * @port_num: /dev/ttyGS* port this interface will use
410 * Context: single threaded during gadget setup
411 *
412 * Returns zero on success, else negative errno.
413 *
414 * Caller must have called @gserial_setup() with enough ports to
415 * handle all the ones it binds. Caller is also responsible
416 * for calling @gserial_cleanup() before module unload.
417 */
obex_bind_config(struct usb_configuration * c,u8 port_num)418 int __init obex_bind_config(struct usb_configuration *c, u8 port_num)
419 {
420 struct f_obex *obex;
421 int status;
422
423 if (!can_support_obex(c))
424 return -EINVAL;
425
426 /* maybe allocate device-global string IDs, and patch descriptors */
427 if (obex_string_defs[OBEX_CTRL_IDX].id == 0) {
428 status = usb_string_id(c->cdev);
429 if (status < 0)
430 return status;
431 obex_string_defs[OBEX_CTRL_IDX].id = status;
432
433 obex_control_intf.iInterface = status;
434
435 status = usb_string_id(c->cdev);
436 if (status < 0)
437 return status;
438 obex_string_defs[OBEX_DATA_IDX].id = status;
439
440 obex_data_nop_intf.iInterface =
441 obex_data_intf.iInterface = status;
442 }
443
444 /* allocate and initialize one new instance */
445 obex = kzalloc(sizeof *obex, GFP_KERNEL);
446 if (!obex)
447 return -ENOMEM;
448
449 obex->port_num = port_num;
450
451 obex->port.connect = obex_connect;
452 obex->port.disconnect = obex_disconnect;
453
454 obex->port.func.name = "obex";
455 obex->port.func.strings = obex_strings;
456 /* descriptors are per-instance copies */
457 obex->port.func.bind = obex_bind;
458 obex->port.func.unbind = obex_unbind;
459 obex->port.func.set_alt = obex_set_alt;
460 obex->port.func.get_alt = obex_get_alt;
461 obex->port.func.disable = obex_disable;
462
463 status = usb_add_function(c, &obex->port.func);
464 if (status)
465 kfree(obex);
466
467 return status;
468 }
469
470 MODULE_AUTHOR("Felipe Balbi");
471 MODULE_LICENSE("GPL");
472