1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * g_ffs.c -- user mode file system API for USB composite function controllers
4 *
5 * Copyright (C) 2010 Samsung Electronics
6 * Author: Michal Nazarewicz <mina86@mina86.com>
7 */
8
9#define pr_fmt(fmt) "g_ffs: " fmt
10
11#include <linux/module.h>
12
13#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
14#include <linux/netdevice.h>
15
16#  if defined USB_ETH_RNDIS
17#    undef USB_ETH_RNDIS
18#  endif
19#  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
20#    define USB_ETH_RNDIS y
21#  endif
22
23#  include "u_ecm.h"
24#  include "u_gether.h"
25#  ifdef USB_ETH_RNDIS
26#    include "u_rndis.h"
27#    include "rndis.h"
28#  endif
29#  include "u_ether.h"
30
31USB_ETHERNET_MODULE_PARAMETERS();
32
33#  ifdef CONFIG_USB_FUNCTIONFS_ETH
34static int eth_bind_config(struct usb_configuration *c);
35static struct usb_function_instance *fi_ecm;
36static struct usb_function *f_ecm;
37static struct usb_function_instance *fi_geth;
38static struct usb_function *f_geth;
39#  endif
40#  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
41static int bind_rndis_config(struct usb_configuration *c);
42static struct usb_function_instance *fi_rndis;
43static struct usb_function *f_rndis;
44#  endif
45#endif
46
47#include "u_fs.h"
48
49#define DRIVER_NAME	"g_ffs"
50#define DRIVER_DESC	"USB Function Filesystem"
51#define DRIVER_VERSION	"24 Aug 2004"
52
53MODULE_DESCRIPTION(DRIVER_DESC);
54MODULE_AUTHOR("Michal Nazarewicz");
55MODULE_LICENSE("GPL");
56
57#define GFS_VENDOR_ID	0x1d6b	/* Linux Foundation */
58#define GFS_PRODUCT_ID	0x0105	/* FunctionFS Gadget */
59
60#define GFS_MAX_DEVS	10
61
62USB_GADGET_COMPOSITE_OPTIONS();
63
64static struct usb_device_descriptor gfs_dev_desc = {
65	.bLength		= sizeof gfs_dev_desc,
66	.bDescriptorType	= USB_DT_DEVICE,
67
68	/* .bcdUSB = DYNAMIC */
69	.bDeviceClass		= USB_CLASS_PER_INTERFACE,
70
71	.idVendor		= cpu_to_le16(GFS_VENDOR_ID),
72	.idProduct		= cpu_to_le16(GFS_PRODUCT_ID),
73};
74
75static char *func_names[GFS_MAX_DEVS];
76static unsigned int func_num;
77
78module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
79MODULE_PARM_DESC(bDeviceClass, "USB Device class");
80module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
81MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
82module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
83MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
84module_param_array_named(functions, func_names, charp, &func_num, 0);
85MODULE_PARM_DESC(functions, "USB Functions list");
86
87static const struct usb_descriptor_header *gfs_otg_desc[2];
88
89/* String IDs are assigned dynamically */
90static struct usb_string gfs_strings[] = {
91	[USB_GADGET_MANUFACTURER_IDX].s = "",
92	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
93	[USB_GADGET_SERIAL_IDX].s = "",
94#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
95	{ .s = "FunctionFS + RNDIS" },
96#endif
97#ifdef CONFIG_USB_FUNCTIONFS_ETH
98	{ .s = "FunctionFS + ECM" },
99#endif
100#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
101	{ .s = "FunctionFS" },
102#endif
103	{  } /* end of list */
104};
105
106static struct usb_gadget_strings *gfs_dev_strings[] = {
107	&(struct usb_gadget_strings) {
108		.language	= 0x0409,	/* en-us */
109		.strings	= gfs_strings,
110	},
111	NULL,
112};
113
114struct gfs_configuration {
115	struct usb_configuration c;
116	int (*eth)(struct usb_configuration *c);
117	int num;
118};
119
120static struct gfs_configuration gfs_configurations[] = {
121#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
122	{
123		.eth		= bind_rndis_config,
124	},
125#endif
126
127#ifdef CONFIG_USB_FUNCTIONFS_ETH
128	{
129		.eth		= eth_bind_config,
130	},
131#endif
132
133#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
134	{
135	},
136#endif
137};
138
139static void *functionfs_acquire_dev(struct ffs_dev *dev);
140static void functionfs_release_dev(struct ffs_dev *dev);
141static int functionfs_ready_callback(struct ffs_data *ffs);
142static void functionfs_closed_callback(struct ffs_data *ffs);
143static int gfs_bind(struct usb_composite_dev *cdev);
144static int gfs_unbind(struct usb_composite_dev *cdev);
145static int gfs_do_config(struct usb_configuration *c);
146
147
148static struct usb_composite_driver gfs_driver = {
149	.name		= DRIVER_NAME,
150	.dev		= &gfs_dev_desc,
151	.strings	= gfs_dev_strings,
152	.max_speed	= USB_SPEED_SUPER,
153	.bind		= gfs_bind,
154	.unbind		= gfs_unbind,
155};
156
157static unsigned int missing_funcs;
158static bool gfs_registered;
159static bool gfs_single_func;
160static struct usb_function_instance **fi_ffs;
161static struct usb_function **f_ffs[] = {
162#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
163	NULL,
164#endif
165
166#ifdef CONFIG_USB_FUNCTIONFS_ETH
167	NULL,
168#endif
169
170#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
171	NULL,
172#endif
173};
174
175#define N_CONF ARRAY_SIZE(f_ffs)
176
177static int __init gfs_init(void)
178{
179	struct f_fs_opts *opts;
180	int i;
181	int ret = 0;
182
183	if (func_num < 2) {
184		gfs_single_func = true;
185		func_num = 1;
186	}
187
188	/*
189	 * Allocate in one chunk for easier maintenance
190	 */
191	f_ffs[0] = kcalloc(func_num * N_CONF, sizeof(*f_ffs), GFP_KERNEL);
192	if (!f_ffs[0]) {
193		ret = -ENOMEM;
194		goto no_func;
195	}
196	for (i = 1; i < N_CONF; ++i)
197		f_ffs[i] = f_ffs[0] + i * func_num;
198
199	fi_ffs = kcalloc(func_num, sizeof(*fi_ffs), GFP_KERNEL);
200	if (!fi_ffs) {
201		ret = -ENOMEM;
202		goto no_func;
203	}
204
205	for (i = 0; i < func_num; i++) {
206		fi_ffs[i] = usb_get_function_instance("ffs");
207		if (IS_ERR(fi_ffs[i])) {
208			ret = PTR_ERR(fi_ffs[i]);
209			--i;
210			goto no_dev;
211		}
212		opts = to_f_fs_opts(fi_ffs[i]);
213		if (gfs_single_func)
214			ret = ffs_single_dev(opts->dev);
215		else
216			ret = ffs_name_dev(opts->dev, func_names[i]);
217		if (ret)
218			goto no_dev;
219		opts->dev->ffs_ready_callback = functionfs_ready_callback;
220		opts->dev->ffs_closed_callback = functionfs_closed_callback;
221		opts->dev->ffs_acquire_dev_callback = functionfs_acquire_dev;
222		opts->dev->ffs_release_dev_callback = functionfs_release_dev;
223		opts->no_configfs = true;
224	}
225
226	missing_funcs = func_num;
227
228	return 0;
229no_dev:
230	while (i >= 0)
231		usb_put_function_instance(fi_ffs[i--]);
232	kfree(fi_ffs);
233no_func:
234	kfree(f_ffs[0]);
235	return ret;
236}
237module_init(gfs_init);
238
239static void __exit gfs_exit(void)
240{
241	int i;
242
243	if (gfs_registered)
244		usb_composite_unregister(&gfs_driver);
245	gfs_registered = false;
246
247	kfree(f_ffs[0]);
248
249	for (i = 0; i < func_num; i++)
250		usb_put_function_instance(fi_ffs[i]);
251
252	kfree(fi_ffs);
253}
254module_exit(gfs_exit);
255
256static void *functionfs_acquire_dev(struct ffs_dev *dev)
257{
258	if (!try_module_get(THIS_MODULE))
259		return ERR_PTR(-ENOENT);
260
261	return NULL;
262}
263
264static void functionfs_release_dev(struct ffs_dev *dev)
265{
266	module_put(THIS_MODULE);
267}
268
269/*
270 * The caller of this function takes ffs_lock
271 */
272static int functionfs_ready_callback(struct ffs_data *ffs)
273{
274	int ret = 0;
275
276	if (--missing_funcs)
277		return 0;
278
279	if (gfs_registered)
280		return -EBUSY;
281
282	gfs_registered = true;
283
284	ret = usb_composite_probe(&gfs_driver);
285	if (unlikely(ret < 0)) {
286		++missing_funcs;
287		gfs_registered = false;
288	}
289
290	return ret;
291}
292
293/*
294 * The caller of this function takes ffs_lock
295 */
296static void functionfs_closed_callback(struct ffs_data *ffs)
297{
298	missing_funcs++;
299
300	if (gfs_registered)
301		usb_composite_unregister(&gfs_driver);
302	gfs_registered = false;
303}
304
305/*
306 * It is assumed that gfs_bind is called from a context where ffs_lock is held
307 */
308static int gfs_bind(struct usb_composite_dev *cdev)
309{
310#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
311	struct net_device *net;
312#endif
313	int ret, i;
314
315	if (missing_funcs)
316		return -ENODEV;
317#if defined CONFIG_USB_FUNCTIONFS_ETH
318	if (can_support_ecm(cdev->gadget)) {
319		struct f_ecm_opts *ecm_opts;
320
321		fi_ecm = usb_get_function_instance("ecm");
322		if (IS_ERR(fi_ecm))
323			return PTR_ERR(fi_ecm);
324		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
325		net = ecm_opts->net;
326	} else {
327		struct f_gether_opts *geth_opts;
328
329		fi_geth = usb_get_function_instance("geth");
330		if (IS_ERR(fi_geth))
331			return PTR_ERR(fi_geth);
332		geth_opts = container_of(fi_geth, struct f_gether_opts,
333					 func_inst);
334		net = geth_opts->net;
335	}
336#endif
337
338#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
339	{
340		fi_rndis = usb_get_function_instance("rndis");
341		if (IS_ERR(fi_rndis)) {
342			ret = PTR_ERR(fi_rndis);
343			goto error;
344		}
345#ifndef CONFIG_USB_FUNCTIONFS_ETH
346		net = container_of(fi_rndis, struct f_rndis_opts,
347				   func_inst)->net;
348#endif
349	}
350#endif
351
352#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
353	gether_set_qmult(net, qmult);
354	if (!gether_set_host_addr(net, host_addr))
355		pr_info("using host ethernet address: %s", host_addr);
356	if (!gether_set_dev_addr(net, dev_addr))
357		pr_info("using self ethernet address: %s", dev_addr);
358#endif
359
360#if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
361	gether_set_gadget(net, cdev->gadget);
362	ret = gether_register_netdev(net);
363	if (ret)
364		goto error_rndis;
365
366	if (can_support_ecm(cdev->gadget)) {
367		struct f_ecm_opts *ecm_opts;
368
369		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
370		ecm_opts->bound = true;
371	} else {
372		struct f_gether_opts *geth_opts;
373
374		geth_opts = container_of(fi_geth, struct f_gether_opts,
375					 func_inst);
376		geth_opts->bound = true;
377	}
378
379	rndis_borrow_net(fi_rndis, net);
380#endif
381
382	/* TODO: gstrings_attach? */
383	ret = usb_string_ids_tab(cdev, gfs_strings);
384	if (unlikely(ret < 0))
385		goto error_rndis;
386	gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
387
388	if (gadget_is_otg(cdev->gadget) && !gfs_otg_desc[0]) {
389		struct usb_descriptor_header *usb_desc;
390
391		usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
392		if (!usb_desc) {
393			ret = -ENOMEM;
394			goto error_rndis;
395		}
396		usb_otg_descriptor_init(cdev->gadget, usb_desc);
397		gfs_otg_desc[0] = usb_desc;
398		gfs_otg_desc[1] = NULL;
399	}
400
401	for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
402		struct gfs_configuration *c = gfs_configurations + i;
403		int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
404
405		c->c.label			= gfs_strings[sid].s;
406		c->c.iConfiguration		= gfs_strings[sid].id;
407		c->c.bConfigurationValue	= 1 + i;
408		c->c.bmAttributes		= USB_CONFIG_ATT_SELFPOWER;
409
410		c->num = i;
411
412		ret = usb_add_config(cdev, &c->c, gfs_do_config);
413		if (unlikely(ret < 0))
414			goto error_unbind;
415	}
416	usb_composite_overwrite_options(cdev, &coverwrite);
417	return 0;
418
419/* TODO */
420error_unbind:
421	kfree(gfs_otg_desc[0]);
422	gfs_otg_desc[0] = NULL;
423error_rndis:
424#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
425	usb_put_function_instance(fi_rndis);
426error:
427#endif
428#if defined CONFIG_USB_FUNCTIONFS_ETH
429	if (can_support_ecm(cdev->gadget))
430		usb_put_function_instance(fi_ecm);
431	else
432		usb_put_function_instance(fi_geth);
433#endif
434	return ret;
435}
436
437/*
438 * It is assumed that gfs_unbind is called from a context where ffs_lock is held
439 */
440static int gfs_unbind(struct usb_composite_dev *cdev)
441{
442	int i;
443
444#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
445	usb_put_function(f_rndis);
446	usb_put_function_instance(fi_rndis);
447#endif
448
449#if defined CONFIG_USB_FUNCTIONFS_ETH
450	if (can_support_ecm(cdev->gadget)) {
451		usb_put_function(f_ecm);
452		usb_put_function_instance(fi_ecm);
453	} else {
454		usb_put_function(f_geth);
455		usb_put_function_instance(fi_geth);
456	}
457#endif
458	for (i = 0; i < N_CONF * func_num; ++i)
459		usb_put_function(*(f_ffs[0] + i));
460
461	kfree(gfs_otg_desc[0]);
462	gfs_otg_desc[0] = NULL;
463
464	return 0;
465}
466
467/*
468 * It is assumed that gfs_do_config is called from a context where
469 * ffs_lock is held
470 */
471static int gfs_do_config(struct usb_configuration *c)
472{
473	struct gfs_configuration *gc =
474		container_of(c, struct gfs_configuration, c);
475	int i;
476	int ret;
477
478	if (missing_funcs)
479		return -ENODEV;
480
481	if (gadget_is_otg(c->cdev->gadget)) {
482		c->descriptors = gfs_otg_desc;
483		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
484	}
485
486	if (gc->eth) {
487		ret = gc->eth(c);
488		if (unlikely(ret < 0))
489			return ret;
490	}
491
492	for (i = 0; i < func_num; i++) {
493		f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
494		if (IS_ERR(f_ffs[gc->num][i])) {
495			ret = PTR_ERR(f_ffs[gc->num][i]);
496			goto error;
497		}
498		ret = usb_add_function(c, f_ffs[gc->num][i]);
499		if (ret < 0) {
500			usb_put_function(f_ffs[gc->num][i]);
501			goto error;
502		}
503	}
504
505	/*
506	 * After previous do_configs there may be some invalid
507	 * pointers in c->interface array.  This happens every time
508	 * a user space function with fewer interfaces than a user
509	 * space function that was run before the new one is run.  The
510	 * compasit's set_config() assumes that if there is no more
511	 * then MAX_CONFIG_INTERFACES interfaces in a configuration
512	 * then there is a NULL pointer after the last interface in
513	 * c->interface array.  We need to make sure this is true.
514	 */
515	if (c->next_interface_id < ARRAY_SIZE(c->interface))
516		c->interface[c->next_interface_id] = NULL;
517
518	return 0;
519error:
520	while (--i >= 0) {
521		if (!IS_ERR(f_ffs[gc->num][i]))
522			usb_remove_function(c, f_ffs[gc->num][i]);
523		usb_put_function(f_ffs[gc->num][i]);
524	}
525	return ret;
526}
527
528#ifdef CONFIG_USB_FUNCTIONFS_ETH
529
530static int eth_bind_config(struct usb_configuration *c)
531{
532	int status = 0;
533
534	if (can_support_ecm(c->cdev->gadget)) {
535		f_ecm = usb_get_function(fi_ecm);
536		if (IS_ERR(f_ecm))
537			return PTR_ERR(f_ecm);
538
539		status = usb_add_function(c, f_ecm);
540		if (status < 0)
541			usb_put_function(f_ecm);
542
543	} else {
544		f_geth = usb_get_function(fi_geth);
545		if (IS_ERR(f_geth))
546			return PTR_ERR(f_geth);
547
548		status = usb_add_function(c, f_geth);
549		if (status < 0)
550			usb_put_function(f_geth);
551	}
552	return status;
553}
554
555#endif
556
557#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
558
559static int bind_rndis_config(struct usb_configuration *c)
560{
561	int status = 0;
562
563	f_rndis = usb_get_function(fi_rndis);
564	if (IS_ERR(f_rndis))
565		return PTR_ERR(f_rndis);
566
567	status = usb_add_function(c, f_rndis);
568	if (status < 0)
569		usb_put_function(f_rndis);
570
571	return status;
572}
573
574#endif
575