xref: /linux/drivers/usb/gadget/legacy/g_ffs.c (revision 005438a8eef063495ac059d128eea71b58de50e5) 
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 
35 USB_ETHERNET_MODULE_PARAMETERS();
36 
37 #  ifdef CONFIG_USB_FUNCTIONFS_ETH
38 static int eth_bind_config(struct usb_configuration *c);
39 static struct usb_function_instance *fi_ecm;
40 static struct usb_function *f_ecm;
41 static struct usb_function_instance *fi_geth;
42 static struct usb_function *f_geth;
43 #  endif
44 #  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
45 static int bind_rndis_config(struct usb_configuration *c);
46 static struct usb_function_instance *fi_rndis;
47 static 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 
57 MODULE_DESCRIPTION(DRIVER_DESC);
58 MODULE_AUTHOR("Michal Nazarewicz");
59 MODULE_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 
66 USB_GADGET_COMPOSITE_OPTIONS();
67 
68 static 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 
79 static char *func_names[GFS_MAX_DEVS];
80 static unsigned int func_num;
81 
82 module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
83 MODULE_PARM_DESC(bDeviceClass, "USB Device class");
84 module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
85 MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
86 module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
87 MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
88 module_param_array_named(functions, func_names, charp, &func_num, 0);
89 MODULE_PARM_DESC(functions, "USB Functions list");
90 
91 static const struct usb_descriptor_header *gfs_otg_desc[] = {
92 	(const struct usb_descriptor_header *)
93 	&(const struct usb_otg_descriptor) {
94 		.bLength		= sizeof(struct usb_otg_descriptor),
95 		.bDescriptorType	= USB_DT_OTG,
96 
97 		/*
98 		 * REVISIT SRP-only hardware is possible, although
99 		 * it would not be called "OTG" ...
100 		 */
101 		.bmAttributes		= USB_OTG_SRP | USB_OTG_HNP,
102 	},
103 
104 	NULL
105 };
106 
107 /* String IDs are assigned dynamically */
108 static struct usb_string gfs_strings[] = {
109 	[USB_GADGET_MANUFACTURER_IDX].s = "",
110 	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
111 	[USB_GADGET_SERIAL_IDX].s = "",
112 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
113 	{ .s = "FunctionFS + RNDIS" },
114 #endif
115 #ifdef CONFIG_USB_FUNCTIONFS_ETH
116 	{ .s = "FunctionFS + ECM" },
117 #endif
118 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
119 	{ .s = "FunctionFS" },
120 #endif
121 	{  } /* end of list */
122 };
123 
124 static struct usb_gadget_strings *gfs_dev_strings[] = {
125 	&(struct usb_gadget_strings) {
126 		.language	= 0x0409,	/* en-us */
127 		.strings	= gfs_strings,
128 	},
129 	NULL,
130 };
131 
132 struct gfs_configuration {
133 	struct usb_configuration c;
134 	int (*eth)(struct usb_configuration *c);
135 	int num;
136 };
137 
138 static struct gfs_configuration gfs_configurations[] = {
139 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
140 	{
141 		.eth		= bind_rndis_config,
142 	},
143 #endif
144 
145 #ifdef CONFIG_USB_FUNCTIONFS_ETH
146 	{
147 		.eth		= eth_bind_config,
148 	},
149 #endif
150 
151 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
152 	{
153 	},
154 #endif
155 };
156 
157 static void *functionfs_acquire_dev(struct ffs_dev *dev);
158 static void functionfs_release_dev(struct ffs_dev *dev);
159 static int functionfs_ready_callback(struct ffs_data *ffs);
160 static void functionfs_closed_callback(struct ffs_data *ffs);
161 static int gfs_bind(struct usb_composite_dev *cdev);
162 static int gfs_unbind(struct usb_composite_dev *cdev);
163 static int gfs_do_config(struct usb_configuration *c);
164 
165 
166 static struct usb_composite_driver gfs_driver = {
167 	.name		= DRIVER_NAME,
168 	.dev		= &gfs_dev_desc,
169 	.strings	= gfs_dev_strings,
170 	.max_speed	= USB_SPEED_HIGH,
171 	.bind		= gfs_bind,
172 	.unbind		= gfs_unbind,
173 };
174 
175 static unsigned int missing_funcs;
176 static bool gfs_registered;
177 static bool gfs_single_func;
178 static struct usb_function_instance **fi_ffs;
179 static struct usb_function **f_ffs[] = {
180 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
181 	NULL,
182 #endif
183 
184 #ifdef CONFIG_USB_FUNCTIONFS_ETH
185 	NULL,
186 #endif
187 
188 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
189 	NULL,
190 #endif
191 };
192 
193 #define N_CONF ARRAY_SIZE(f_ffs)
194 
195 static int __init gfs_init(void)
196 {
197 	struct f_fs_opts *opts;
198 	int i;
199 	int ret = 0;
200 
201 	ENTER();
202 
203 	if (func_num < 2) {
204 		gfs_single_func = true;
205 		func_num = 1;
206 	}
207 
208 	/*
209 	 * Allocate in one chunk for easier maintenance
210 	 */
211 	f_ffs[0] = kcalloc(func_num * N_CONF, sizeof(*f_ffs), GFP_KERNEL);
212 	if (!f_ffs[0]) {
213 		ret = -ENOMEM;
214 		goto no_func;
215 	}
216 	for (i = 1; i < N_CONF; ++i)
217 		f_ffs[i] = f_ffs[0] + i * func_num;
218 
219 	fi_ffs = kcalloc(func_num, sizeof(*fi_ffs), GFP_KERNEL);
220 	if (!fi_ffs) {
221 		ret = -ENOMEM;
222 		goto no_func;
223 	}
224 
225 	for (i = 0; i < func_num; i++) {
226 		fi_ffs[i] = usb_get_function_instance("ffs");
227 		if (IS_ERR(fi_ffs[i])) {
228 			ret = PTR_ERR(fi_ffs[i]);
229 			--i;
230 			goto no_dev;
231 		}
232 		opts = to_f_fs_opts(fi_ffs[i]);
233 		if (gfs_single_func)
234 			ret = ffs_single_dev(opts->dev);
235 		else
236 			ret = ffs_name_dev(opts->dev, func_names[i]);
237 		if (ret)
238 			goto no_dev;
239 		opts->dev->ffs_ready_callback = functionfs_ready_callback;
240 		opts->dev->ffs_closed_callback = functionfs_closed_callback;
241 		opts->dev->ffs_acquire_dev_callback = functionfs_acquire_dev;
242 		opts->dev->ffs_release_dev_callback = functionfs_release_dev;
243 		opts->no_configfs = true;
244 	}
245 
246 	missing_funcs = func_num;
247 
248 	return 0;
249 no_dev:
250 	while (i >= 0)
251 		usb_put_function_instance(fi_ffs[i--]);
252 	kfree(fi_ffs);
253 no_func:
254 	kfree(f_ffs[0]);
255 	return ret;
256 }
257 module_init(gfs_init);
258 
259 static void __exit gfs_exit(void)
260 {
261 	int i;
262 
263 	ENTER();
264 
265 	if (gfs_registered)
266 		usb_composite_unregister(&gfs_driver);
267 	gfs_registered = false;
268 
269 	kfree(f_ffs[0]);
270 
271 	for (i = 0; i < func_num; i++)
272 		usb_put_function_instance(fi_ffs[i]);
273 
274 	kfree(fi_ffs);
275 }
276 module_exit(gfs_exit);
277 
278 static void *functionfs_acquire_dev(struct ffs_dev *dev)
279 {
280 	if (!try_module_get(THIS_MODULE))
281 		return ERR_PTR(-ENOENT);
282 
283 	return NULL;
284 }
285 
286 static void functionfs_release_dev(struct ffs_dev *dev)
287 {
288 	module_put(THIS_MODULE);
289 }
290 
291 /*
292  * The caller of this function takes ffs_lock
293  */
294 static int functionfs_ready_callback(struct ffs_data *ffs)
295 {
296 	int ret = 0;
297 
298 	if (--missing_funcs)
299 		return 0;
300 
301 	if (gfs_registered)
302 		return -EBUSY;
303 
304 	gfs_registered = true;
305 
306 	ret = usb_composite_probe(&gfs_driver);
307 	if (unlikely(ret < 0)) {
308 		++missing_funcs;
309 		gfs_registered = false;
310 	}
311 
312 	return ret;
313 }
314 
315 /*
316  * The caller of this function takes ffs_lock
317  */
318 static void functionfs_closed_callback(struct ffs_data *ffs)
319 {
320 	missing_funcs++;
321 
322 	if (gfs_registered)
323 		usb_composite_unregister(&gfs_driver);
324 	gfs_registered = false;
325 }
326 
327 /*
328  * It is assumed that gfs_bind is called from a context where ffs_lock is held
329  */
330 static int gfs_bind(struct usb_composite_dev *cdev)
331 {
332 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
333 	struct net_device *net;
334 #endif
335 	int ret, i;
336 
337 	ENTER();
338 
339 	if (missing_funcs)
340 		return -ENODEV;
341 #if defined CONFIG_USB_FUNCTIONFS_ETH
342 	if (can_support_ecm(cdev->gadget)) {
343 		struct f_ecm_opts *ecm_opts;
344 
345 		fi_ecm = usb_get_function_instance("ecm");
346 		if (IS_ERR(fi_ecm))
347 			return PTR_ERR(fi_ecm);
348 		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
349 		net = ecm_opts->net;
350 	} else {
351 		struct f_gether_opts *geth_opts;
352 
353 		fi_geth = usb_get_function_instance("geth");
354 		if (IS_ERR(fi_geth))
355 			return PTR_ERR(fi_geth);
356 		geth_opts = container_of(fi_geth, struct f_gether_opts,
357 					 func_inst);
358 		net = geth_opts->net;
359 	}
360 #endif
361 
362 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
363 	{
364 		struct f_rndis_opts *rndis_opts;
365 
366 		fi_rndis = usb_get_function_instance("rndis");
367 		if (IS_ERR(fi_rndis)) {
368 			ret = PTR_ERR(fi_rndis);
369 			goto error;
370 		}
371 		rndis_opts = container_of(fi_rndis, struct f_rndis_opts,
372 					  func_inst);
373 #ifndef CONFIG_USB_FUNCTIONFS_ETH
374 		net = rndis_opts->net;
375 #endif
376 	}
377 #endif
378 
379 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
380 	gether_set_qmult(net, qmult);
381 	if (!gether_set_host_addr(net, host_addr))
382 		pr_info("using host ethernet address: %s", host_addr);
383 	if (!gether_set_dev_addr(net, dev_addr))
384 		pr_info("using self ethernet address: %s", dev_addr);
385 #endif
386 
387 #if defined CONFIG_USB_FUNCTIONFS_RNDIS && defined CONFIG_USB_FUNCTIONFS_ETH
388 	gether_set_gadget(net, cdev->gadget);
389 	ret = gether_register_netdev(net);
390 	if (ret)
391 		goto error_rndis;
392 
393 	if (can_support_ecm(cdev->gadget)) {
394 		struct f_ecm_opts *ecm_opts;
395 
396 		ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
397 		ecm_opts->bound = true;
398 	} else {
399 		struct f_gether_opts *geth_opts;
400 
401 		geth_opts = container_of(fi_geth, struct f_gether_opts,
402 					 func_inst);
403 		geth_opts->bound = true;
404 	}
405 
406 	rndis_borrow_net(fi_rndis, net);
407 #endif
408 
409 	/* TODO: gstrings_attach? */
410 	ret = usb_string_ids_tab(cdev, gfs_strings);
411 	if (unlikely(ret < 0))
412 		goto error_rndis;
413 	gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
414 
415 	for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
416 		struct gfs_configuration *c = gfs_configurations + i;
417 		int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
418 
419 		c->c.label			= gfs_strings[sid].s;
420 		c->c.iConfiguration		= gfs_strings[sid].id;
421 		c->c.bConfigurationValue	= 1 + i;
422 		c->c.bmAttributes		= USB_CONFIG_ATT_SELFPOWER;
423 
424 		c->num = i;
425 
426 		ret = usb_add_config(cdev, &c->c, gfs_do_config);
427 		if (unlikely(ret < 0))
428 			goto error_unbind;
429 	}
430 	usb_composite_overwrite_options(cdev, &coverwrite);
431 	return 0;
432 
433 /* TODO */
434 error_unbind:
435 error_rndis:
436 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
437 	usb_put_function_instance(fi_rndis);
438 error:
439 #endif
440 #if defined CONFIG_USB_FUNCTIONFS_ETH
441 	if (can_support_ecm(cdev->gadget))
442 		usb_put_function_instance(fi_ecm);
443 	else
444 		usb_put_function_instance(fi_geth);
445 #endif
446 	return ret;
447 }
448 
449 /*
450  * It is assumed that gfs_unbind is called from a context where ffs_lock is held
451  */
452 static int gfs_unbind(struct usb_composite_dev *cdev)
453 {
454 	int i;
455 
456 	ENTER();
457 
458 
459 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
460 	usb_put_function(f_rndis);
461 	usb_put_function_instance(fi_rndis);
462 #endif
463 
464 #if defined CONFIG_USB_FUNCTIONFS_ETH
465 	if (can_support_ecm(cdev->gadget)) {
466 		usb_put_function(f_ecm);
467 		usb_put_function_instance(fi_ecm);
468 	} else {
469 		usb_put_function(f_geth);
470 		usb_put_function_instance(fi_geth);
471 	}
472 #endif
473 	for (i = 0; i < N_CONF * func_num; ++i)
474 		usb_put_function(*(f_ffs[0] + i));
475 
476 	return 0;
477 }
478 
479 /*
480  * It is assumed that gfs_do_config is called from a context where
481  * ffs_lock is held
482  */
483 static int gfs_do_config(struct usb_configuration *c)
484 {
485 	struct gfs_configuration *gc =
486 		container_of(c, struct gfs_configuration, c);
487 	int i;
488 	int ret;
489 
490 	if (missing_funcs)
491 		return -ENODEV;
492 
493 	if (gadget_is_otg(c->cdev->gadget)) {
494 		c->descriptors = gfs_otg_desc;
495 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
496 	}
497 
498 	if (gc->eth) {
499 		ret = gc->eth(c);
500 		if (unlikely(ret < 0))
501 			return ret;
502 	}
503 
504 	for (i = 0; i < func_num; i++) {
505 		f_ffs[gc->num][i] = usb_get_function(fi_ffs[i]);
506 		if (IS_ERR(f_ffs[gc->num][i])) {
507 			ret = PTR_ERR(f_ffs[gc->num][i]);
508 			goto error;
509 		}
510 		ret = usb_add_function(c, f_ffs[gc->num][i]);
511 		if (ret < 0) {
512 			usb_put_function(f_ffs[gc->num][i]);
513 			goto error;
514 		}
515 	}
516 
517 	/*
518 	 * After previous do_configs there may be some invalid
519 	 * pointers in c->interface array.  This happens every time
520 	 * a user space function with fewer interfaces than a user
521 	 * space function that was run before the new one is run.  The
522 	 * compasit's set_config() assumes that if there is no more
523 	 * then MAX_CONFIG_INTERFACES interfaces in a configuration
524 	 * then there is a NULL pointer after the last interface in
525 	 * c->interface array.  We need to make sure this is true.
526 	 */
527 	if (c->next_interface_id < ARRAY_SIZE(c->interface))
528 		c->interface[c->next_interface_id] = NULL;
529 
530 	return 0;
531 error:
532 	while (--i >= 0) {
533 		if (!IS_ERR(f_ffs[gc->num][i]))
534 			usb_remove_function(c, f_ffs[gc->num][i]);
535 		usb_put_function(f_ffs[gc->num][i]);
536 	}
537 	return ret;
538 }
539 
540 #ifdef CONFIG_USB_FUNCTIONFS_ETH
541 
542 static int eth_bind_config(struct usb_configuration *c)
543 {
544 	int status = 0;
545 
546 	if (can_support_ecm(c->cdev->gadget)) {
547 		f_ecm = usb_get_function(fi_ecm);
548 		if (IS_ERR(f_ecm))
549 			return PTR_ERR(f_ecm);
550 
551 		status = usb_add_function(c, f_ecm);
552 		if (status < 0)
553 			usb_put_function(f_ecm);
554 
555 	} else {
556 		f_geth = usb_get_function(fi_geth);
557 		if (IS_ERR(f_geth))
558 			return PTR_ERR(f_geth);
559 
560 		status = usb_add_function(c, f_geth);
561 		if (status < 0)
562 			usb_put_function(f_geth);
563 	}
564 	return status;
565 }
566 
567 #endif
568 
569 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
570 
571 static int bind_rndis_config(struct usb_configuration *c)
572 {
573 	int status = 0;
574 
575 	f_rndis = usb_get_function(fi_rndis);
576 	if (IS_ERR(f_rndis))
577 		return PTR_ERR(f_rndis);
578 
579 	status = usb_add_function(c, f_rndis);
580 	if (status < 0)
581 		usb_put_function(f_rndis);
582 
583 	return status;
584 }
585 
586 #endif
587