1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * f_obex.c -- USB CDC OBEX function driver
4 *
5 * Copyright (C) 2008 Nokia Corporation
6 * Contact: Felipe Balbi <felipe.balbi@nokia.com>
7 *
8 * Based on f_acm.c by Al Borchers and David Brownell.
9 */
10
11 /* #define VERBOSE_DEBUG */
12
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/device.h>
16 #include <linux/module.h>
17
18 #include "u_serial.h"
19
20
21 /*
22 * This CDC OBEX function support just packages a TTY-ish byte stream.
23 * A user mode server will put it into "raw" mode and handle all the
24 * relevant protocol details ... this is just a kernel passthrough.
25 * When possible, we prevent gadget enumeration until that server is
26 * ready to handle the commands.
27 */
28
29 struct f_obex {
30 struct gserial port;
31 u8 ctrl_id;
32 u8 data_id;
33 u8 cur_alt;
34 u8 port_num;
35 };
36
func_to_obex(struct usb_function * f)37 static inline struct f_obex *func_to_obex(struct usb_function *f)
38 {
39 return container_of(f, struct f_obex, port.func);
40 }
41
port_to_obex(struct gserial * p)42 static inline struct f_obex *port_to_obex(struct gserial *p)
43 {
44 return container_of(p, struct f_obex, port);
45 }
46
47 /*-------------------------------------------------------------------------*/
48
49 #define OBEX_CTRL_IDX 0
50 #define OBEX_DATA_IDX 1
51
52 static struct usb_string obex_string_defs[] = {
53 [OBEX_CTRL_IDX].s = "CDC Object Exchange (OBEX)",
54 [OBEX_DATA_IDX].s = "CDC OBEX Data",
55 { }, /* end of list */
56 };
57
58 static struct usb_gadget_strings obex_string_table = {
59 .language = 0x0409, /* en-US */
60 .strings = obex_string_defs,
61 };
62
63 static struct usb_gadget_strings *obex_strings[] = {
64 &obex_string_table,
65 NULL,
66 };
67
68 /*-------------------------------------------------------------------------*/
69
70 static struct usb_interface_descriptor obex_control_intf = {
71 .bLength = sizeof(obex_control_intf),
72 .bDescriptorType = USB_DT_INTERFACE,
73 .bInterfaceNumber = 0,
74
75 .bAlternateSetting = 0,
76 .bNumEndpoints = 0,
77 .bInterfaceClass = USB_CLASS_COMM,
78 .bInterfaceSubClass = USB_CDC_SUBCLASS_OBEX,
79 };
80
81 static struct usb_interface_descriptor obex_data_nop_intf = {
82 .bLength = sizeof(obex_data_nop_intf),
83 .bDescriptorType = USB_DT_INTERFACE,
84 .bInterfaceNumber = 1,
85
86 .bAlternateSetting = 0,
87 .bNumEndpoints = 0,
88 .bInterfaceClass = USB_CLASS_CDC_DATA,
89 };
90
91 static struct usb_interface_descriptor obex_data_intf = {
92 .bLength = sizeof(obex_data_intf),
93 .bDescriptorType = USB_DT_INTERFACE,
94 .bInterfaceNumber = 2,
95
96 .bAlternateSetting = 1,
97 .bNumEndpoints = 2,
98 .bInterfaceClass = USB_CLASS_CDC_DATA,
99 };
100
101 static struct usb_cdc_header_desc obex_cdc_header_desc = {
102 .bLength = sizeof(obex_cdc_header_desc),
103 .bDescriptorType = USB_DT_CS_INTERFACE,
104 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
105 .bcdCDC = cpu_to_le16(0x0120),
106 };
107
108 static struct usb_cdc_union_desc obex_cdc_union_desc = {
109 .bLength = sizeof(obex_cdc_union_desc),
110 .bDescriptorType = USB_DT_CS_INTERFACE,
111 .bDescriptorSubType = USB_CDC_UNION_TYPE,
112 .bMasterInterface0 = 1,
113 .bSlaveInterface0 = 2,
114 };
115
116 static struct usb_cdc_obex_desc obex_desc = {
117 .bLength = sizeof(obex_desc),
118 .bDescriptorType = USB_DT_CS_INTERFACE,
119 .bDescriptorSubType = USB_CDC_OBEX_TYPE,
120 .bcdVersion = cpu_to_le16(0x0100),
121 };
122
123 /* High-Speed Support */
124
125 static struct usb_endpoint_descriptor obex_hs_ep_out_desc = {
126 .bLength = USB_DT_ENDPOINT_SIZE,
127 .bDescriptorType = USB_DT_ENDPOINT,
128
129 .bEndpointAddress = USB_DIR_OUT,
130 .bmAttributes = USB_ENDPOINT_XFER_BULK,
131 .wMaxPacketSize = cpu_to_le16(512),
132 };
133
134 static struct usb_endpoint_descriptor obex_hs_ep_in_desc = {
135 .bLength = USB_DT_ENDPOINT_SIZE,
136 .bDescriptorType = USB_DT_ENDPOINT,
137
138 .bEndpointAddress = USB_DIR_IN,
139 .bmAttributes = USB_ENDPOINT_XFER_BULK,
140 .wMaxPacketSize = cpu_to_le16(512),
141 };
142
143 static struct usb_descriptor_header *hs_function[] = {
144 (struct usb_descriptor_header *) &obex_control_intf,
145 (struct usb_descriptor_header *) &obex_cdc_header_desc,
146 (struct usb_descriptor_header *) &obex_desc,
147 (struct usb_descriptor_header *) &obex_cdc_union_desc,
148
149 (struct usb_descriptor_header *) &obex_data_nop_intf,
150 (struct usb_descriptor_header *) &obex_data_intf,
151 (struct usb_descriptor_header *) &obex_hs_ep_in_desc,
152 (struct usb_descriptor_header *) &obex_hs_ep_out_desc,
153 NULL,
154 };
155
156 /* Full-Speed Support */
157
158 static struct usb_endpoint_descriptor obex_fs_ep_in_desc = {
159 .bLength = USB_DT_ENDPOINT_SIZE,
160 .bDescriptorType = USB_DT_ENDPOINT,
161
162 .bEndpointAddress = USB_DIR_IN,
163 .bmAttributes = USB_ENDPOINT_XFER_BULK,
164 };
165
166 static struct usb_endpoint_descriptor obex_fs_ep_out_desc = {
167 .bLength = USB_DT_ENDPOINT_SIZE,
168 .bDescriptorType = USB_DT_ENDPOINT,
169
170 .bEndpointAddress = USB_DIR_OUT,
171 .bmAttributes = USB_ENDPOINT_XFER_BULK,
172 };
173
174 static struct usb_descriptor_header *fs_function[] = {
175 (struct usb_descriptor_header *) &obex_control_intf,
176 (struct usb_descriptor_header *) &obex_cdc_header_desc,
177 (struct usb_descriptor_header *) &obex_desc,
178 (struct usb_descriptor_header *) &obex_cdc_union_desc,
179
180 (struct usb_descriptor_header *) &obex_data_nop_intf,
181 (struct usb_descriptor_header *) &obex_data_intf,
182 (struct usb_descriptor_header *) &obex_fs_ep_in_desc,
183 (struct usb_descriptor_header *) &obex_fs_ep_out_desc,
184 NULL,
185 };
186
187 /*-------------------------------------------------------------------------*/
188
obex_set_alt(struct usb_function * f,unsigned intf,unsigned alt)189 static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
190 {
191 struct f_obex *obex = func_to_obex(f);
192 struct usb_composite_dev *cdev = f->config->cdev;
193
194 if (intf == obex->ctrl_id) {
195 if (alt != 0)
196 goto fail;
197 /* NOP */
198 dev_dbg(&cdev->gadget->dev,
199 "reset obex ttyGS%d control\n", obex->port_num);
200
201 } else if (intf == obex->data_id) {
202 if (alt > 1)
203 goto fail;
204
205 if (obex->port.in->enabled) {
206 dev_dbg(&cdev->gadget->dev,
207 "reset obex ttyGS%d\n", obex->port_num);
208 gserial_disconnect(&obex->port);
209 }
210
211 if (!obex->port.in->desc || !obex->port.out->desc) {
212 dev_dbg(&cdev->gadget->dev,
213 "init obex ttyGS%d\n", obex->port_num);
214 if (config_ep_by_speed(cdev->gadget, f,
215 obex->port.in) ||
216 config_ep_by_speed(cdev->gadget, f,
217 obex->port.out)) {
218 obex->port.out->desc = NULL;
219 obex->port.in->desc = NULL;
220 goto fail;
221 }
222 }
223
224 if (alt == 1) {
225 dev_dbg(&cdev->gadget->dev,
226 "activate obex ttyGS%d\n", obex->port_num);
227 gserial_connect(&obex->port, obex->port_num);
228 }
229
230 } else
231 goto fail;
232
233 obex->cur_alt = alt;
234
235 return 0;
236
237 fail:
238 return -EINVAL;
239 }
240
obex_get_alt(struct usb_function * f,unsigned intf)241 static int obex_get_alt(struct usb_function *f, unsigned intf)
242 {
243 struct f_obex *obex = func_to_obex(f);
244
245 return obex->cur_alt;
246 }
247
obex_disable(struct usb_function * f)248 static void obex_disable(struct usb_function *f)
249 {
250 struct f_obex *obex = func_to_obex(f);
251 struct usb_composite_dev *cdev = f->config->cdev;
252
253 dev_dbg(&cdev->gadget->dev, "obex ttyGS%d disable\n", obex->port_num);
254 gserial_disconnect(&obex->port);
255 }
256
257 /*-------------------------------------------------------------------------*/
258
obex_connect(struct gserial * g)259 static void obex_connect(struct gserial *g)
260 {
261 struct f_obex *obex = port_to_obex(g);
262 struct usb_composite_dev *cdev = g->func.config->cdev;
263 int status;
264
265 status = usb_function_activate(&g->func);
266 if (status)
267 dev_dbg(&cdev->gadget->dev,
268 "obex ttyGS%d function activate --> %d\n",
269 obex->port_num, status);
270 }
271
obex_disconnect(struct gserial * g)272 static void obex_disconnect(struct gserial *g)
273 {
274 struct f_obex *obex = port_to_obex(g);
275 struct usb_composite_dev *cdev = g->func.config->cdev;
276 int status;
277
278 status = usb_function_deactivate(&g->func);
279 if (status)
280 dev_dbg(&cdev->gadget->dev,
281 "obex ttyGS%d function deactivate --> %d\n",
282 obex->port_num, status);
283 }
284
285 /*-------------------------------------------------------------------------*/
286
287 /* Some controllers can't support CDC OBEX ... */
can_support_obex(struct usb_configuration * c)288 static inline bool can_support_obex(struct usb_configuration *c)
289 {
290 /* Since the first interface is a NOP, we can ignore the
291 * issue of multi-interface support on most controllers.
292 *
293 * Altsettings are mandatory, however...
294 */
295 if (!gadget_is_altset_supported(c->cdev->gadget))
296 return false;
297
298 /* everything else is *probably* fine ... */
299 return true;
300 }
301
obex_bind(struct usb_configuration * c,struct usb_function * f)302 static int obex_bind(struct usb_configuration *c, struct usb_function *f)
303 {
304 struct usb_composite_dev *cdev = c->cdev;
305 struct f_obex *obex = func_to_obex(f);
306 struct usb_string *us;
307 int status;
308 struct usb_ep *ep;
309
310 if (!can_support_obex(c))
311 return -EINVAL;
312
313 us = usb_gstrings_attach(cdev, obex_strings,
314 ARRAY_SIZE(obex_string_defs));
315 if (IS_ERR(us))
316 return PTR_ERR(us);
317 obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
318 obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
319 obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;
320
321 /* allocate instance-specific interface IDs, and patch descriptors */
322
323 status = usb_interface_id(c, f);
324 if (status < 0)
325 goto fail;
326 obex->ctrl_id = status;
327
328 obex_control_intf.bInterfaceNumber = status;
329 obex_cdc_union_desc.bMasterInterface0 = status;
330
331 status = usb_interface_id(c, f);
332 if (status < 0)
333 goto fail;
334 obex->data_id = status;
335
336 obex_data_nop_intf.bInterfaceNumber = status;
337 obex_data_intf.bInterfaceNumber = status;
338 obex_cdc_union_desc.bSlaveInterface0 = status;
339
340 /* allocate instance-specific endpoints */
341
342 status = -ENODEV;
343 ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
344 if (!ep)
345 goto fail;
346 obex->port.in = ep;
347
348 ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
349 if (!ep)
350 goto fail;
351 obex->port.out = ep;
352
353 /* support all relevant hardware speeds... we expect that when
354 * hardware is dual speed, all bulk-capable endpoints work at
355 * both speeds
356 */
357
358 obex_hs_ep_in_desc.bEndpointAddress =
359 obex_fs_ep_in_desc.bEndpointAddress;
360 obex_hs_ep_out_desc.bEndpointAddress =
361 obex_fs_ep_out_desc.bEndpointAddress;
362
363 status = usb_assign_descriptors(f, fs_function, hs_function, NULL,
364 NULL);
365 if (status)
366 goto fail;
367
368 dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
369 obex->port_num,
370 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
371 obex->port.in->name, obex->port.out->name);
372
373 return 0;
374
375 fail:
376 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
377
378 return status;
379 }
380
to_f_serial_opts(struct config_item * item)381 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
382 {
383 return container_of(to_config_group(item), struct f_serial_opts,
384 func_inst.group);
385 }
386
obex_attr_release(struct config_item * item)387 static void obex_attr_release(struct config_item *item)
388 {
389 struct f_serial_opts *opts = to_f_serial_opts(item);
390
391 usb_put_function_instance(&opts->func_inst);
392 }
393
394 static struct configfs_item_operations obex_item_ops = {
395 .release = obex_attr_release,
396 };
397
f_obex_port_num_show(struct config_item * item,char * page)398 static ssize_t f_obex_port_num_show(struct config_item *item, char *page)
399 {
400 return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
401 }
402
403 CONFIGFS_ATTR_RO(f_obex_, port_num);
404
405 static struct configfs_attribute *acm_attrs[] = {
406 &f_obex_attr_port_num,
407 NULL,
408 };
409
410 static const struct config_item_type obex_func_type = {
411 .ct_item_ops = &obex_item_ops,
412 .ct_attrs = acm_attrs,
413 .ct_owner = THIS_MODULE,
414 };
415
obex_free_inst(struct usb_function_instance * f)416 static void obex_free_inst(struct usb_function_instance *f)
417 {
418 struct f_serial_opts *opts;
419
420 opts = container_of(f, struct f_serial_opts, func_inst);
421 gserial_free_line(opts->port_num);
422 kfree(opts);
423 }
424
obex_alloc_inst(void)425 static struct usb_function_instance *obex_alloc_inst(void)
426 {
427 struct f_serial_opts *opts;
428 int ret;
429
430 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
431 if (!opts)
432 return ERR_PTR(-ENOMEM);
433
434 opts->func_inst.free_func_inst = obex_free_inst;
435 ret = gserial_alloc_line_no_console(&opts->port_num);
436 if (ret) {
437 kfree(opts);
438 return ERR_PTR(ret);
439 }
440 config_group_init_type_name(&opts->func_inst.group, "",
441 &obex_func_type);
442
443 return &opts->func_inst;
444 }
445
obex_free(struct usb_function * f)446 static void obex_free(struct usb_function *f)
447 {
448 struct f_obex *obex;
449
450 obex = func_to_obex(f);
451 kfree(obex);
452 }
453
obex_unbind(struct usb_configuration * c,struct usb_function * f)454 static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
455 {
456 usb_free_all_descriptors(f);
457 }
458
obex_alloc(struct usb_function_instance * fi)459 static struct usb_function *obex_alloc(struct usb_function_instance *fi)
460 {
461 struct f_obex *obex;
462 struct f_serial_opts *opts;
463
464 /* allocate and initialize one new instance */
465 obex = kzalloc(sizeof(*obex), GFP_KERNEL);
466 if (!obex)
467 return ERR_PTR(-ENOMEM);
468
469 opts = container_of(fi, struct f_serial_opts, func_inst);
470
471 obex->port_num = opts->port_num;
472
473 obex->port.connect = obex_connect;
474 obex->port.disconnect = obex_disconnect;
475
476 obex->port.func.name = "obex";
477 /* descriptors are per-instance copies */
478 obex->port.func.bind = obex_bind;
479 obex->port.func.unbind = obex_unbind;
480 obex->port.func.set_alt = obex_set_alt;
481 obex->port.func.get_alt = obex_get_alt;
482 obex->port.func.disable = obex_disable;
483 obex->port.func.free_func = obex_free;
484 obex->port.func.bind_deactivated = true;
485
486 return &obex->port.func;
487 }
488
489 DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
490 MODULE_AUTHOR("Felipe Balbi");
491 MODULE_LICENSE("GPL");
492