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  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				port_num;
 39	u8				can_activate;
 40};
 41
 42static inline struct f_obex *func_to_obex(struct usb_function *f)
 43{
 44	return container_of(f, struct f_obex, port.func);
 45}
 46
 47static 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
 57static 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
 63static struct usb_gadget_strings obex_string_table = {
 64	.language		= 0x0409,	/* en-US */
 65	.strings		= obex_string_defs,
 66};
 67
 68static struct usb_gadget_strings *obex_strings[] = {
 69	&obex_string_table,
 70	NULL,
 71};
 72
 73/*-------------------------------------------------------------------------*/
 74
 75static 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
 86static 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
 96static 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
106static 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
113static 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
121static 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
130static 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
139static 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
148static 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
163static 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
171static 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
179static 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
194static 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
236fail:
237	return -EINVAL;
238}
239
240static 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
250static 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
261static 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
276static 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
293static int __init
294obex_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
370fail:
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
382static void
383obex_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 ... */
392static 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 */
418int __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
470MODULE_AUTHOR("Felipe Balbi");
471MODULE_LICENSE("GPL");