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
34struct f_obex {
35	struct gserial			port;
36	u8				ctrl_id;
37	u8				data_id;
38	u8				cur_alt;
39	u8				port_num;
40	u8				can_activate;
41};
42
43static inline struct f_obex *func_to_obex(struct usb_function *f)
44{
45	return container_of(f, struct f_obex, port.func);
46}
47
48static inline struct f_obex *port_to_obex(struct gserial *p)
49{
50	return container_of(p, struct f_obex, port);
51}
52
53/*-------------------------------------------------------------------------*/
54
55#define OBEX_CTRL_IDX	0
56#define OBEX_DATA_IDX	1
57
58static struct usb_string obex_string_defs[] = {
59	[OBEX_CTRL_IDX].s	= "CDC Object Exchange (OBEX)",
60	[OBEX_DATA_IDX].s	= "CDC OBEX Data",
61	{  },	/* end of list */
62};
63
64static struct usb_gadget_strings obex_string_table = {
65	.language		= 0x0409,	/* en-US */
66	.strings		= obex_string_defs,
67};
68
69static struct usb_gadget_strings *obex_strings[] = {
70	&obex_string_table,
71	NULL,
72};
73
74/*-------------------------------------------------------------------------*/
75
76static struct usb_interface_descriptor obex_control_intf = {
77	.bLength		= sizeof(obex_control_intf),
78	.bDescriptorType	= USB_DT_INTERFACE,
79	.bInterfaceNumber	= 0,
80
81	.bAlternateSetting	= 0,
82	.bNumEndpoints		= 0,
83	.bInterfaceClass	= USB_CLASS_COMM,
84	.bInterfaceSubClass	= USB_CDC_SUBCLASS_OBEX,
85};
86
87static struct usb_interface_descriptor obex_data_nop_intf = {
88	.bLength		= sizeof(obex_data_nop_intf),
89	.bDescriptorType	= USB_DT_INTERFACE,
90	.bInterfaceNumber	= 1,
91
92	.bAlternateSetting	= 0,
93	.bNumEndpoints		= 0,
94	.bInterfaceClass	= USB_CLASS_CDC_DATA,
95};
96
97static struct usb_interface_descriptor obex_data_intf = {
98	.bLength		= sizeof(obex_data_intf),
99	.bDescriptorType	= USB_DT_INTERFACE,
100	.bInterfaceNumber	= 2,
101
102	.bAlternateSetting	= 1,
103	.bNumEndpoints		= 2,
104	.bInterfaceClass	= USB_CLASS_CDC_DATA,
105};
106
107static struct usb_cdc_header_desc obex_cdc_header_desc = {
108	.bLength		= sizeof(obex_cdc_header_desc),
109	.bDescriptorType	= USB_DT_CS_INTERFACE,
110	.bDescriptorSubType	= USB_CDC_HEADER_TYPE,
111	.bcdCDC			= cpu_to_le16(0x0120),
112};
113
114static struct usb_cdc_union_desc obex_cdc_union_desc = {
115	.bLength		= sizeof(obex_cdc_union_desc),
116	.bDescriptorType	= USB_DT_CS_INTERFACE,
117	.bDescriptorSubType	= USB_CDC_UNION_TYPE,
118	.bMasterInterface0	= 1,
119	.bSlaveInterface0	= 2,
120};
121
122static struct usb_cdc_obex_desc obex_desc = {
123	.bLength		= sizeof(obex_desc),
124	.bDescriptorType	= USB_DT_CS_INTERFACE,
125	.bDescriptorSubType	= USB_CDC_OBEX_TYPE,
126	.bcdVersion		= cpu_to_le16(0x0100),
127};
128
129/* High-Speed Support */
130
131static struct usb_endpoint_descriptor obex_hs_ep_out_desc = {
132	.bLength		= USB_DT_ENDPOINT_SIZE,
133	.bDescriptorType	= USB_DT_ENDPOINT,
134
135	.bEndpointAddress	= USB_DIR_OUT,
136	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
137	.wMaxPacketSize		= cpu_to_le16(512),
138};
139
140static struct usb_endpoint_descriptor obex_hs_ep_in_desc = {
141	.bLength		= USB_DT_ENDPOINT_SIZE,
142	.bDescriptorType	= USB_DT_ENDPOINT,
143
144	.bEndpointAddress	= USB_DIR_IN,
145	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
146	.wMaxPacketSize		= cpu_to_le16(512),
147};
148
149static struct usb_descriptor_header *hs_function[] = {
150	(struct usb_descriptor_header *) &obex_control_intf,
151	(struct usb_descriptor_header *) &obex_cdc_header_desc,
152	(struct usb_descriptor_header *) &obex_desc,
153	(struct usb_descriptor_header *) &obex_cdc_union_desc,
154
155	(struct usb_descriptor_header *) &obex_data_nop_intf,
156	(struct usb_descriptor_header *) &obex_data_intf,
157	(struct usb_descriptor_header *) &obex_hs_ep_in_desc,
158	(struct usb_descriptor_header *) &obex_hs_ep_out_desc,
159	NULL,
160};
161
162/* Full-Speed Support */
163
164static struct usb_endpoint_descriptor obex_fs_ep_in_desc = {
165	.bLength		= USB_DT_ENDPOINT_SIZE,
166	.bDescriptorType	= USB_DT_ENDPOINT,
167
168	.bEndpointAddress	= USB_DIR_IN,
169	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
170};
171
172static struct usb_endpoint_descriptor obex_fs_ep_out_desc = {
173	.bLength		= USB_DT_ENDPOINT_SIZE,
174	.bDescriptorType	= USB_DT_ENDPOINT,
175
176	.bEndpointAddress	= USB_DIR_OUT,
177	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
178};
179
180static struct usb_descriptor_header *fs_function[] = {
181	(struct usb_descriptor_header *) &obex_control_intf,
182	(struct usb_descriptor_header *) &obex_cdc_header_desc,
183	(struct usb_descriptor_header *) &obex_desc,
184	(struct usb_descriptor_header *) &obex_cdc_union_desc,
185
186	(struct usb_descriptor_header *) &obex_data_nop_intf,
187	(struct usb_descriptor_header *) &obex_data_intf,
188	(struct usb_descriptor_header *) &obex_fs_ep_in_desc,
189	(struct usb_descriptor_header *) &obex_fs_ep_out_desc,
190	NULL,
191};
192
193/*-------------------------------------------------------------------------*/
194
195static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
196{
197	struct f_obex		*obex = func_to_obex(f);
198	struct usb_composite_dev *cdev = f->config->cdev;
199
200	if (intf == obex->ctrl_id) {
201		if (alt != 0)
202			goto fail;
203		/* NOP */
204		dev_dbg(&cdev->gadget->dev,
205			"reset obex ttyGS%d control\n", obex->port_num);
206
207	} else if (intf == obex->data_id) {
208		if (alt > 1)
209			goto fail;
210
211		if (obex->port.in->driver_data) {
212			dev_dbg(&cdev->gadget->dev,
213				"reset obex ttyGS%d\n", obex->port_num);
214			gserial_disconnect(&obex->port);
215		}
216
217		if (!obex->port.in->desc || !obex->port.out->desc) {
218			dev_dbg(&cdev->gadget->dev,
219				"init obex ttyGS%d\n", obex->port_num);
220			if (config_ep_by_speed(cdev->gadget, f,
221					       obex->port.in) ||
222			    config_ep_by_speed(cdev->gadget, f,
223					       obex->port.out)) {
224				obex->port.out->desc = NULL;
225				obex->port.in->desc = NULL;
226				goto fail;
227			}
228		}
229
230		if (alt == 1) {
231			dev_dbg(&cdev->gadget->dev,
232				"activate obex ttyGS%d\n", obex->port_num);
233			gserial_connect(&obex->port, obex->port_num);
234		}
235
236	} else
237		goto fail;
238
239	obex->cur_alt = alt;
240
241	return 0;
242
243fail:
244	return -EINVAL;
245}
246
247static int obex_get_alt(struct usb_function *f, unsigned intf)
248{
249	struct f_obex		*obex = func_to_obex(f);
250
251	return obex->cur_alt;
252}
253
254static void obex_disable(struct usb_function *f)
255{
256	struct f_obex	*obex = func_to_obex(f);
257	struct usb_composite_dev *cdev = f->config->cdev;
258
259	dev_dbg(&cdev->gadget->dev, "obex ttyGS%d disable\n", obex->port_num);
260	gserial_disconnect(&obex->port);
261}
262
263/*-------------------------------------------------------------------------*/
264
265static void obex_connect(struct gserial *g)
266{
267	struct f_obex		*obex = port_to_obex(g);
268	struct usb_composite_dev *cdev = g->func.config->cdev;
269	int			status;
270
271	if (!obex->can_activate)
272		return;
273
274	status = usb_function_activate(&g->func);
275	if (status)
276		dev_dbg(&cdev->gadget->dev,
277			"obex ttyGS%d function activate --> %d\n",
278			obex->port_num, status);
279}
280
281static void obex_disconnect(struct gserial *g)
282{
283	struct f_obex		*obex = port_to_obex(g);
284	struct usb_composite_dev *cdev = g->func.config->cdev;
285	int			status;
286
287	if (!obex->can_activate)
288		return;
289
290	status = usb_function_deactivate(&g->func);
291	if (status)
292		dev_dbg(&cdev->gadget->dev,
293			"obex ttyGS%d function deactivate --> %d\n",
294			obex->port_num, status);
295}
296
297/*-------------------------------------------------------------------------*/
298
299/* Some controllers can't support CDC OBEX ... */
300static inline bool can_support_obex(struct usb_configuration *c)
301{
302	/* Since the first interface is a NOP, we can ignore the
303	 * issue of multi-interface support on most controllers.
304	 *
305	 * Altsettings are mandatory, however...
306	 */
307	if (!gadget_supports_altsettings(c->cdev->gadget))
308		return false;
309
310	/* everything else is *probably* fine ... */
311	return true;
312}
313
314static int obex_bind(struct usb_configuration *c, struct usb_function *f)
315{
316	struct usb_composite_dev *cdev = c->cdev;
317	struct f_obex		*obex = func_to_obex(f);
318	struct usb_string	*us;
319	int			status;
320	struct usb_ep		*ep;
321
322	if (!can_support_obex(c))
323		return -EINVAL;
324
325	us = usb_gstrings_attach(cdev, obex_strings,
326				 ARRAY_SIZE(obex_string_defs));
327	if (IS_ERR(us))
328		return PTR_ERR(us);
329	obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
330	obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
331	obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;
332
333	/* allocate instance-specific interface IDs, and patch descriptors */
334
335	status = usb_interface_id(c, f);
336	if (status < 0)
337		goto fail;
338	obex->ctrl_id = status;
339
340	obex_control_intf.bInterfaceNumber = status;
341	obex_cdc_union_desc.bMasterInterface0 = status;
342
343	status = usb_interface_id(c, f);
344	if (status < 0)
345		goto fail;
346	obex->data_id = status;
347
348	obex_data_nop_intf.bInterfaceNumber = status;
349	obex_data_intf.bInterfaceNumber = status;
350	obex_cdc_union_desc.bSlaveInterface0 = status;
351
352	/* allocate instance-specific endpoints */
353
354	status = -ENODEV;
355	ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
356	if (!ep)
357		goto fail;
358	obex->port.in = ep;
359	ep->driver_data = cdev;	/* claim */
360
361	ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
362	if (!ep)
363		goto fail;
364	obex->port.out = ep;
365	ep->driver_data = cdev;	/* claim */
366
367	/* support all relevant hardware speeds... we expect that when
368	 * hardware is dual speed, all bulk-capable endpoints work at
369	 * both speeds
370	 */
371
372	obex_hs_ep_in_desc.bEndpointAddress =
373		obex_fs_ep_in_desc.bEndpointAddress;
374	obex_hs_ep_out_desc.bEndpointAddress =
375		obex_fs_ep_out_desc.bEndpointAddress;
376
377	status = usb_assign_descriptors(f, fs_function, hs_function, NULL);
378	if (status)
379		goto fail;
380
381	/* Avoid letting this gadget enumerate until the userspace
382	 * OBEX server is active.
383	 */
384	status = usb_function_deactivate(f);
385	if (status < 0)
386		WARNING(cdev, "obex ttyGS%d: can't prevent enumeration, %d\n",
387			obex->port_num, status);
388	else
389		obex->can_activate = true;
390
391
392	dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
393		obex->port_num,
394		gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
395		obex->port.in->name, obex->port.out->name);
396
397	return 0;
398
399fail:
400	/* we might as well release our claims on endpoints */
401	if (obex->port.out)
402		obex->port.out->driver_data = NULL;
403	if (obex->port.in)
404		obex->port.in->driver_data = NULL;
405
406	ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
407
408	return status;
409}
410
411static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
412{
413	return container_of(to_config_group(item), struct f_serial_opts,
414			    func_inst.group);
415}
416
417CONFIGFS_ATTR_STRUCT(f_serial_opts);
418static ssize_t f_obex_attr_show(struct config_item *item,
419				struct configfs_attribute *attr,
420				char *page)
421{
422	struct f_serial_opts *opts = to_f_serial_opts(item);
423	struct f_serial_opts_attribute *f_serial_opts_attr =
424		container_of(attr, struct f_serial_opts_attribute, attr);
425	ssize_t ret = 0;
426
427	if (f_serial_opts_attr->show)
428		ret = f_serial_opts_attr->show(opts, page);
429
430	return ret;
431}
432
433static void obex_attr_release(struct config_item *item)
434{
435	struct f_serial_opts *opts = to_f_serial_opts(item);
436
437	usb_put_function_instance(&opts->func_inst);
438}
439
440static struct configfs_item_operations obex_item_ops = {
441	.release	= obex_attr_release,
442	.show_attribute = f_obex_attr_show,
443};
444
445static ssize_t f_obex_port_num_show(struct f_serial_opts *opts, char *page)
446{
447	return sprintf(page, "%u\n", opts->port_num);
448}
449
450static struct f_serial_opts_attribute f_obex_port_num =
451	__CONFIGFS_ATTR_RO(port_num, f_obex_port_num_show);
452
453static struct configfs_attribute *acm_attrs[] = {
454	&f_obex_port_num.attr,
455	NULL,
456};
457
458static struct config_item_type obex_func_type = {
459	.ct_item_ops	= &obex_item_ops,
460	.ct_attrs	= acm_attrs,
461	.ct_owner	= THIS_MODULE,
462};
463
464static void obex_free_inst(struct usb_function_instance *f)
465{
466	struct f_serial_opts *opts;
467
468	opts = container_of(f, struct f_serial_opts, func_inst);
469	gserial_free_line(opts->port_num);
470	kfree(opts);
471}
472
473static struct usb_function_instance *obex_alloc_inst(void)
474{
475	struct f_serial_opts *opts;
476	int ret;
477
478	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
479	if (!opts)
480		return ERR_PTR(-ENOMEM);
481
482	opts->func_inst.free_func_inst = obex_free_inst;
483	ret = gserial_alloc_line(&opts->port_num);
484	if (ret) {
485		kfree(opts);
486		return ERR_PTR(ret);
487	}
488	config_group_init_type_name(&opts->func_inst.group, "",
489				    &obex_func_type);
490
491	return &opts->func_inst;
492}
493
494static void obex_free(struct usb_function *f)
495{
496	struct f_obex *obex;
497
498	obex = func_to_obex(f);
499	kfree(obex);
500}
501
502static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
503{
504	usb_free_all_descriptors(f);
505}
506
507static struct usb_function *obex_alloc(struct usb_function_instance *fi)
508{
509	struct f_obex	*obex;
510	struct f_serial_opts *opts;
511
512	/* allocate and initialize one new instance */
513	obex = kzalloc(sizeof(*obex), GFP_KERNEL);
514	if (!obex)
515		return ERR_PTR(-ENOMEM);
516
517	opts = container_of(fi, struct f_serial_opts, func_inst);
518
519	obex->port_num = opts->port_num;
520
521	obex->port.connect = obex_connect;
522	obex->port.disconnect = obex_disconnect;
523
524	obex->port.func.name = "obex";
525	/* descriptors are per-instance copies */
526	obex->port.func.bind = obex_bind;
527	obex->port.func.unbind = obex_unbind;
528	obex->port.func.set_alt = obex_set_alt;
529	obex->port.func.get_alt = obex_get_alt;
530	obex->port.func.disable = obex_disable;
531	obex->port.func.free_func = obex_free;
532
533	return &obex->port.func;
534}
535
536DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
537MODULE_AUTHOR("Felipe Balbi");
538MODULE_LICENSE("GPL");
539