1/*
2 * g_ffs.c -- user mode file system API for USB composite function controllers
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 * Author: Michal Nazarewicz <mina86@mina86.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13#define pr_fmt(fmt) "g_ffs: " fmt
14
15#include <linux/module.h>
16
17#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
18#include <linux/netdevice.h>
19
20#  if defined USB_ETH_RNDIS
21#    undef USB_ETH_RNDIS
22#  endif
23#  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
24#    define USB_ETH_RNDIS y
25#  endif
26
27#  include "u_ecm.h"
28#  include "u_gether.h"
29#  ifdef USB_ETH_RNDIS
30#    include "u_rndis.h"
31#    include "rndis.h"
32#  endif
33#  include "u_ether.h"
34
35USB_ETHERNET_MODULE_PARAMETERS();
36
37#  ifdef CONFIG_USB_FUNCTIONFS_ETH
38static int eth_bind_config(struct usb_configuration *c);
39static struct usb_function_instance *fi_ecm;
40static struct usb_function *f_ecm;
41static struct usb_function_instance *fi_geth;
42static struct usb_function *f_geth;
43#  endif
44#  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
45static int bind_rndis_config(struct usb_configuration *c);
46static struct usb_function_instance *fi_rndis;
47static struct usb_function *f_rndis;
48#  endif
49#endif
50
51#include "u_fs.h"
52
53#define DRIVER_NAME	"g_ffs"
54#define DRIVER_DESC	"USB Function Filesystem"
55#define DRIVER_VERSION	"24 Aug 2004"
56
57MODULE_DESCRIPTION(DRIVER_DESC);
58MODULE_AUTHOR("Michal Nazarewicz");
59MODULE_LICENSE("GPL");
60
61#define GFS_VENDOR_ID	0x1d6b	/* Linux Foundation */
62#define GFS_PRODUCT_ID	0x0105	/* FunctionFS Gadget */
63
64#define GFS_MAX_DEVS	10
65
66USB_GADGET_COMPOSITE_OPTIONS();
67
68static struct usb_device_descriptor gfs_dev_desc = {
69	.bLength		= sizeof gfs_dev_desc,
70	.bDescriptorType	= USB_DT_DEVICE,
71
72	.bcdUSB			= cpu_to_le16(0x0200),
73	.bDeviceClass		= USB_CLASS_PER_INTERFACE,
74
75	.idVendor		= cpu_to_le16(GFS_VENDOR_ID),
76	.idProduct		= cpu_to_le16(GFS_PRODUCT_ID),
77};
78
79static char *func_names[GFS_MAX_DEVS];
80static unsigned int func_num;
81
82module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
83MODULE_PARM_DESC(bDeviceClass, "USB Device class");
84module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
85MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
86module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
87MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
88module_param_array_named(functions, func_names, charp, &func_num, 0);
89MODULE_PARM_DESC(functions, "USB Functions list");
90
91static const struct usb_descriptor_header *gfs_otg_desc[2];
92
93/* String IDs are assigned dynamically */
94static struct usb_string gfs_strings[] = {
95	[USB_GADGET_MANUFACTURER_IDX].s = "",
96	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
97	[USB_GADGET_SERIAL_IDX].s = "",
98#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
99	{ .s = "FunctionFS + RNDIS" },
100#endif
101#ifdef CONFIG_USB_FUNCTIONFS_ETH
102	{ .s = "FunctionFS + ECM" },
103#endif
104#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
105	{ .s = "FunctionFS" },
106#endif
107	{  } /* end of list */
108};
109
110static struct usb_gadget_strings *gfs_dev_strings[] = {
111	&(struct usb_gadget_strings) {
112		.language	= 0x0409,	/* en-us */
113		.strings	= gfs_strings,
114	},
115	NULL,
116};
117
118struct gfs_configuration {
119	struct usb_configuration c;
120	int (*eth)(struct usb_configuration *c);
121	int num;
122};
123
124static struct gfs_configuration gfs_configurations[] = {
125#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
126	{
127		.eth		= bind_rndis_config,
128	},
129#endif
130
131#ifdef CONFIG_USB_FUNCTIONFS_ETH
132	{
133		.eth		= eth_bind_config,
134	},
135#endif
136
137#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
138	{
139	},
140#endif
141};
142
143static void *functionfs_acquire_dev(struct ffs_dev *dev);
144static void functionfs_release_dev(struct ffs_dev *dev);
145static int functionfs_ready_callback(struct ffs_data *ffs);
146static void functionfs_closed_callback(struct ffs_data *ffs);
147static int gfs_bind(struct usb_composite_dev *cdev);
148static int gfs_unbind(struct usb_composite_dev *cdev);
149static int gfs_do_config(struct usb_configuration *c);
150
151
152static struct usb_composite_driver gfs_driver = {
153	.name		= DRIVER_NAME,
154	.dev		= &gfs_dev_desc,
155	.strings	= gfs_dev_strings,
156	.max_speed	= USB_SPEED_HIGH,
157	.bind		= gfs_bind,
158	.unbind		= gfs_unbind,
159};
160
161static unsigned int missing_funcs;
162static bool gfs_registered;
163static bool gfs_single_func;
164static struct usb_function_instance **fi_ffs;
165static struct usb_function **f_ffs[] = {
166#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
167	NULL,
168#endif
169
170#ifdef CONFIG_USB_FUNCTIONFS_ETH
171	NULL,
172#endif
173
174#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
175	NULL,
176#endif
177};
178
179#define N_CONF ARRAY_SIZE(f_ffs)
180
181static int __init gfs_init(void)
182{
183	struct f_fs_opts *opts;
184	int i;
185	int ret = 0;
186
187	ENTER();
188
189	if (func_num < 2) {
190		gfs_single_func = true;
191		func_num = 1;
192	}
193
194	/*
195	 * Allocate in one chunk for easier maintenance
196	 */
197	f_ffs[0] = kcalloc(func_num * N_CONF, sizeof(*f_ffs), GFP_KERNEL);
198	if (!f_ffs[0]) {
199		ret = -ENOMEM;
200		goto no_func;
201	}
202	for (i = 1; i < N_CONF; ++i)
203		f_ffs[i] = f_ffs[0] + i * func_num;
204
205	fi_ffs = kcalloc(func_num, sizeof(*fi_ffs), GFP_KERNEL);
206	if (!fi_ffs) {
207		ret = -ENOMEM;
208		goto no_func;
209	}
210
211	for (i = 0; i < func_num; i++) {
212		fi_ffs[i] = usb_get_function_instance("ffs");
213		if (IS_ERR(fi_ffs[i])) {
214			ret = PTR_ERR(fi_ffs[i]);
215			--i;
216			goto no_dev;
217		}
218		opts = to_f_fs_opts(fi_ffs[i]);
219		if (gfs_single_func)
220			ret = ffs_single_dev(opts->dev);
221		else
222			ret = ffs_name_dev(opts->dev, func_names[i]);
223		if (ret)
224			goto no_dev;
225		opts->dev->ffs_ready_callback = functionfs_ready_callback;
226		opts->dev->ffs_closed_callback = functionfs_closed_callback;
227		opts->dev->ffs_acquire_dev_callback = functionfs_acquire_dev;
228		opts->dev->ffs_release_dev_callback = functionfs_release_dev;
229		opts->no_configfs = true;
230	}
231
232	missing_funcs = func_num;
233
234	return 0;
235no_dev:
236	while (i >= 0)
237		usb_put_function_instance(fi_ffs[i--]);
238	kfree(fi_ffs);
239no_func:
240	kfree(f_ffs[0]);
241	return ret;
242}
243module_init(gfs_init);
244
245static void __exit gfs_exit(void)
246{
247	int i;
248
249	ENTER();
250
251	if (gfs_registered)
252		usb_composite_unregister(&gfs_driver);
253	gfs_registered = false;
254
255	kfree(f_ffs[0]);
256
257	for (i = 0; i < func_num; i++)
258		usb_put_function_instance(fi_ffs[i]);
259
260	kfree(fi_ffs);
261}
262module_exit(gfs_exit);
263
264static void *functionfs_acquire_dev(struct ffs_dev *dev)
265{
266	if (!try_module_get(THIS_MODULE))
267		return ERR_PTR(-ENOENT);
268
269	return NULL;
270}
271
272static void functionfs_release_dev(struct ffs_dev *dev)
273{
274	module_put(THIS_MODULE);
275}
276
277/*
278 * The caller of this function takes ffs_lock
279 */
280static int functionfs_ready_callback(struct ffs_data *ffs)
281{
282	int ret = 0;
283
284	if (--missing_funcs)
285		return 0;
286
287	if (gfs_registered)
288		return -EBUSY;
289
290	gfs_registered = true;
291
292	ret = usb_composite_probe(&gfs_driver);
293	if (unlikely(ret < 0)) {
294		++missing_funcs;
295		gfs_registered = false;
296	}
297
298	return ret;
299}
300
301/*
302 * The caller of this function takes ffs_lock
303 */
304static void functionfs_closed_callback(struct ffs_data *ffs)
305{
306	missing_funcs++;
307
308	if (gfs_registered)
309		usb_composite_unregister(&gfs_driver);
310	gfs_registered = false;
311}
312
313/*
314 * It is assumed that gfs_bind is called from a context where ffs_lock is held
315 */
316static int gfs_bind(struct usb_composite_dev *cdev)
317{
318#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
319	struct net_device *net;
320#endif
321	int ret, i;
322
323	ENTER();
324
325	if (missing_funcs)
326		return -ENODEV;
327#if defined CONFIG_USB_FUNCTIONFS_ETH
328	if (can_support_ecm(cdev->gadget)) {
329		struct f_ecm_opts *ecm_opts;
330
331		fi_ecm = usb_get_function_instance("ecm");
332		if (IS_ERR(fi_ecm))
333			return PTR_ERR(fi_ecm);
334		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
335		net = ecm_opts->net;
336	} else {
337		struct f_gether_opts *geth_opts;
338
339		fi_geth = usb_get_function_instance("geth");
340		if (IS_ERR(fi_geth))
341			return PTR_ERR(fi_geth);
342		geth_opts = container_of(fi_geth, struct f_gether_opts,
343					 func_inst);
344		net = geth_opts->net;
345	}
346#endif
347
348#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
349	{
350		struct f_rndis_opts *rndis_opts;
351
352		fi_rndis = usb_get_function_instance("rndis");
353		if (IS_ERR(fi_rndis)) {
354			ret = PTR_ERR(fi_rndis);
355			goto error;
356		}
357		rndis_opts = container_of(fi_rndis, struct f_rndis_opts,
358					  func_inst);
359#ifndef CONFIG_USB_FUNCTIONFS_ETH
360		net = rndis_opts->net;
361#endif
362	}
363#endif
364
365#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
366	gether_set_qmult(net, qmult);
367	if (!gether_set_host_addr(net, host_addr))
368		pr_info("using host ethernet address: %s", host_addr);
369	if (!gether_set_dev_addr(net, dev_addr))
370		pr_info("using self ethernet address: %s", dev_addr);
371#endif
372
373#if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
374	gether_set_gadget(net, cdev->gadget);
375	ret = gether_register_netdev(net);
376	if (ret)
377		goto error_rndis;
378
379	if (can_support_ecm(cdev->gadget)) {
380		struct f_ecm_opts *ecm_opts;
381
382		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
383		ecm_opts->bound = true;
384	} else {
385		struct f_gether_opts *geth_opts;
386
387		geth_opts = container_of(fi_geth, struct f_gether_opts,
388					 func_inst);
389		geth_opts->bound = true;
390	}
391
392	rndis_borrow_net(fi_rndis, net);
393#endif
394
395	/* TODO: gstrings_attach? */
396	ret = usb_string_ids_tab(cdev, gfs_strings);
397	if (unlikely(ret < 0))
398		goto error_rndis;
399	gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
400
401	if (gadget_is_otg(cdev->gadget) && !gfs_otg_desc[0]) {
402		struct usb_descriptor_header *usb_desc;
403
404		usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
405		if (!usb_desc)
406			goto error_rndis;
407		usb_otg_descriptor_init(cdev->gadget, usb_desc);
408		gfs_otg_desc[0] = usb_desc;
409		gfs_otg_desc[1] = NULL;
410	}
411
412	for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
413		struct gfs_configuration *c = gfs_configurations + i;
414		int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
415
416		c->c.label			= gfs_strings[sid].s;
417		c->c.iConfiguration		= gfs_strings[sid].id;
418		c->c.bConfigurationValue	= 1 + i;
419		c->c.bmAttributes		= USB_CONFIG_ATT_SELFPOWER;
420
421		c->num = i;
422
423		ret = usb_add_config(cdev, &c->c, gfs_do_config);
424		if (unlikely(ret < 0))
425			goto error_unbind;
426	}
427	usb_composite_overwrite_options(cdev, &coverwrite);
428	return 0;
429
430/* TODO */
431error_unbind:
432	kfree(gfs_otg_desc[0]);
433	gfs_otg_desc[0] = NULL;
434error_rndis:
435#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
436	usb_put_function_instance(fi_rndis);
437error:
438#endif
439#if defined CONFIG_USB_FUNCTIONFS_ETH
440	if (can_support_ecm(cdev->gadget))
441		usb_put_function_instance(fi_ecm);
442	else
443		usb_put_function_instance(fi_geth);
444#endif
445	return ret;
446}
447
448/*
449 * It is assumed that gfs_unbind is called from a context where ffs_lock is held
450 */
451static int gfs_unbind(struct usb_composite_dev *cdev)
452{
453	int i;
454
455	ENTER();
456
457
458#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
459	usb_put_function(f_rndis);
460	usb_put_function_instance(fi_rndis);
461#endif
462
463#if defined CONFIG_USB_FUNCTIONFS_ETH
464	if (can_support_ecm(cdev->gadget)) {
465		usb_put_function(f_ecm);
466		usb_put_function_instance(fi_ecm);
467	} else {
468		usb_put_function(f_geth);
469		usb_put_function_instance(fi_geth);
470	}
471#endif
472	for (i = 0; i < N_CONF * func_num; ++i)
473		usb_put_function(*(f_ffs[0] + i));
474
475	kfree(gfs_otg_desc[0]);
476	gfs_otg_desc[0] = NULL;
477
478	return 0;
479}
480
481/*
482 * It is assumed that gfs_do_config is called from a context where
483 * ffs_lock is held
484 */
485static int gfs_do_config(struct usb_configuration *c)
486{
487	struct gfs_configuration *gc =
488		container_of(c, struct gfs_configuration, c);
489	int i;
490	int ret;
491
492	if (missing_funcs)
493		return -ENODEV;
494
495	if (gadget_is_otg(c->cdev->gadget)) {
496		c->descriptors = gfs_otg_desc;
497		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
498	}
499
500	if (gc->eth) {
501		ret = gc->eth(c);
502		if (unlikely(ret < 0))
503			return ret;
504	}
505
506	for (i = 0; i < func_num; i++) {
507		f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
508		if (IS_ERR(f_ffs[gc->num][i])) {
509			ret = PTR_ERR(f_ffs[gc->num][i]);
510			goto error;
511		}
512		ret = usb_add_function(c, f_ffs[gc->num][i]);
513		if (ret < 0) {
514			usb_put_function(f_ffs[gc->num][i]);
515			goto error;
516		}
517	}
518
519	/*
520	 * After previous do_configs there may be some invalid
521	 * pointers in c->interface array.  This happens every time
522	 * a user space function with fewer interfaces than a user
523	 * space function that was run before the new one is run.  The
524	 * compasit's set_config() assumes that if there is no more
525	 * then MAX_CONFIG_INTERFACES interfaces in a configuration
526	 * then there is a NULL pointer after the last interface in
527	 * c->interface array.  We need to make sure this is true.
528	 */
529	if (c->next_interface_id < ARRAY_SIZE(c->interface))
530		c->interface[c->next_interface_id] = NULL;
531
532	return 0;
533error:
534	while (--i >= 0) {
535		if (!IS_ERR(f_ffs[gc->num][i]))
536			usb_remove_function(c, f_ffs[gc->num][i]);
537		usb_put_function(f_ffs[gc->num][i]);
538	}
539	return ret;
540}
541
542#ifdef CONFIG_USB_FUNCTIONFS_ETH
543
544static int eth_bind_config(struct usb_configuration *c)
545{
546	int status = 0;
547
548	if (can_support_ecm(c->cdev->gadget)) {
549		f_ecm = usb_get_function(fi_ecm);
550		if (IS_ERR(f_ecm))
551			return PTR_ERR(f_ecm);
552
553		status = usb_add_function(c, f_ecm);
554		if (status < 0)
555			usb_put_function(f_ecm);
556
557	} else {
558		f_geth = usb_get_function(fi_geth);
559		if (IS_ERR(f_geth))
560			return PTR_ERR(f_geth);
561
562		status = usb_add_function(c, f_geth);
563		if (status < 0)
564			usb_put_function(f_geth);
565	}
566	return status;
567}
568
569#endif
570
571#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
572
573static int bind_rndis_config(struct usb_configuration *c)
574{
575	int status = 0;
576
577	f_rndis = usb_get_function(fi_rndis);
578	if (IS_ERR(f_rndis))
579		return PTR_ERR(f_rndis);
580
581	status = usb_add_function(c, f_rndis);
582	if (status < 0)
583		usb_put_function(f_rndis);
584
585	return status;
586}
587
588#endif
589