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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#include <linux/utsname.h>
17
18/*
19 * kbuild is not very cooperative with respect to linking separately
20 * compiled library objects into one module. So for now we won't use
21 * separate compilation ... ensuring init/exit sections work to shrink
22 * the runtime footprint, and giving us at least some parts of what
23 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
24 */
25
26#include "composite.c"
27#include "usbstring.c"
28#include "config.c"
29#include "epautoconf.c"
30
31#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
32# if defined USB_ETH_RNDIS
33# undef USB_ETH_RNDIS
34# endif
35# ifdef CONFIG_USB_FUNCTIONFS_RNDIS
36# define USB_ETH_RNDIS y
37# endif
38
39# include "f_ecm.c"
40# include "f_subset.c"
41# ifdef USB_ETH_RNDIS
42# include "f_rndis.c"
43# include "rndis.c"
44# endif
45# include "u_ether.c"
46
47static u8 gfs_hostaddr[ETH_ALEN];
48# ifdef CONFIG_USB_FUNCTIONFS_ETH
49static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
50# endif
51#else
52# define gether_cleanup() do { } while (0)
53# define gether_setup(gadget, hostaddr) ((int)0)
54# define gfs_hostaddr NULL
55#endif
56
57#include "f_fs.c"
58
59#define DRIVER_NAME "g_ffs"
60#define DRIVER_DESC "USB Function Filesystem"
61#define DRIVER_VERSION "24 Aug 2004"
62
63MODULE_DESCRIPTION(DRIVER_DESC);
64MODULE_AUTHOR("Michal Nazarewicz");
65MODULE_LICENSE("GPL");
66
67#define GFS_VENDOR_ID 0x1d6b /* Linux Foundation */
68#define GFS_PRODUCT_ID 0x0105 /* FunctionFS Gadget */
69
70#define GFS_MAX_DEVS 10
71
72struct gfs_ffs_obj {
73 const char *name;
74 bool mounted;
75 bool desc_ready;
76 struct ffs_data *ffs_data;
77};
78
79static struct usb_device_descriptor gfs_dev_desc = {
80 .bLength = sizeof gfs_dev_desc,
81 .bDescriptorType = USB_DT_DEVICE,
82
83 .bcdUSB = cpu_to_le16(0x0200),
84 .bDeviceClass = USB_CLASS_PER_INTERFACE,
85
86 .idVendor = cpu_to_le16(GFS_VENDOR_ID),
87 .idProduct = cpu_to_le16(GFS_PRODUCT_ID),
88};
89
90static char *func_names[GFS_MAX_DEVS];
91static unsigned int func_num;
92
93module_param_named(bDeviceClass, gfs_dev_desc.bDeviceClass, byte, 0644);
94MODULE_PARM_DESC(bDeviceClass, "USB Device class");
95module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte, 0644);
96MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
97module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte, 0644);
98MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
99module_param_array_named(functions, func_names, charp, &func_num, 0);
100MODULE_PARM_DESC(functions, "USB Functions list");
101
102static const struct usb_descriptor_header *gfs_otg_desc[] = {
103 (const struct usb_descriptor_header *)
104 &(const struct usb_otg_descriptor) {
105 .bLength = sizeof(struct usb_otg_descriptor),
106 .bDescriptorType = USB_DT_OTG,
107
108 /*
109 * REVISIT SRP-only hardware is possible, although
110 * it would not be called "OTG" ...
111 */
112 .bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
113 },
114
115 NULL
116};
117
118/* String IDs are assigned dynamically */
119static struct usb_string gfs_strings[] = {
120#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
121 { .s = "FunctionFS + RNDIS" },
122#endif
123#ifdef CONFIG_USB_FUNCTIONFS_ETH
124 { .s = "FunctionFS + ECM" },
125#endif
126#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
127 { .s = "FunctionFS" },
128#endif
129 { } /* end of list */
130};
131
132static struct usb_gadget_strings *gfs_dev_strings[] = {
133 &(struct usb_gadget_strings) {
134 .language = 0x0409, /* en-us */
135 .strings = gfs_strings,
136 },
137 NULL,
138};
139
140struct gfs_configuration {
141 struct usb_configuration c;
142 int (*eth)(struct usb_configuration *c, u8 *ethaddr);
143} gfs_configurations[] = {
144#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
145 {
146 .eth = rndis_bind_config,
147 },
148#endif
149
150#ifdef CONFIG_USB_FUNCTIONFS_ETH
151 {
152 .eth = eth_bind_config,
153 },
154#endif
155
156#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
157 {
158 },
159#endif
160};
161
162static int gfs_bind(struct usb_composite_dev *cdev);
163static int gfs_unbind(struct usb_composite_dev *cdev);
164static int gfs_do_config(struct usb_configuration *c);
165
166static 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 .unbind = gfs_unbind,
172 .iProduct = DRIVER_DESC,
173};
174
175static DEFINE_MUTEX(gfs_lock);
176static unsigned int missing_funcs;
177static bool gfs_ether_setup;
178static bool gfs_registered;
179static bool gfs_single_func;
180static struct gfs_ffs_obj *ffs_tab;
181
182static int __init gfs_init(void)
183{
184 int i;
185
186 ENTER();
187
188 if (!func_num) {
189 gfs_single_func = true;
190 func_num = 1;
191 }
192
193 ffs_tab = kcalloc(func_num, sizeof *ffs_tab, GFP_KERNEL);
194 if (!ffs_tab)
195 return -ENOMEM;
196
197 if (!gfs_single_func)
198 for (i = 0; i < func_num; i++)
199 ffs_tab[i].name = func_names[i];
200
201 missing_funcs = func_num;
202
203 return functionfs_init();
204}
205module_init(gfs_init);
206
207static void __exit gfs_exit(void)
208{
209 ENTER();
210 mutex_lock(&gfs_lock);
211
212 if (gfs_registered)
213 usb_composite_unregister(&gfs_driver);
214 gfs_registered = false;
215
216 functionfs_cleanup();
217
218 mutex_unlock(&gfs_lock);
219 kfree(ffs_tab);
220}
221module_exit(gfs_exit);
222
223static struct gfs_ffs_obj *gfs_find_dev(const char *dev_name)
224{
225 int i;
226
227 ENTER();
228
229 if (gfs_single_func)
230 return &ffs_tab[0];
231
232 for (i = 0; i < func_num; i++)
233 if (strcmp(ffs_tab[i].name, dev_name) == 0)
234 return &ffs_tab[i];
235
236 return NULL;
237}
238
239static int functionfs_ready_callback(struct ffs_data *ffs)
240{
241 struct gfs_ffs_obj *ffs_obj;
242 int ret;
243
244 ENTER();
245 mutex_lock(&gfs_lock);
246
247 ffs_obj = ffs->private_data;
248 if (!ffs_obj) {
249 ret = -EINVAL;
250 goto done;
251 }
252
253 if (WARN_ON(ffs_obj->desc_ready)) {
254 ret = -EBUSY;
255 goto done;
256 }
257 ffs_obj->desc_ready = true;
258 ffs_obj->ffs_data = ffs;
259
260 if (--missing_funcs) {
261 ret = 0;
262 goto done;
263 }
264
265 if (gfs_registered) {
266 ret = -EBUSY;
267 goto done;
268 }
269 gfs_registered = true;
270
271 ret = usb_composite_probe(&gfs_driver, gfs_bind);
272 if (unlikely(ret < 0))
273 gfs_registered = false;
274
275done:
276 mutex_unlock(&gfs_lock);
277 return ret;
278}
279
280static void functionfs_closed_callback(struct ffs_data *ffs)
281{
282 struct gfs_ffs_obj *ffs_obj;
283
284 ENTER();
285 mutex_lock(&gfs_lock);
286
287 ffs_obj = ffs->private_data;
288 if (!ffs_obj)
289 goto done;
290
291 ffs_obj->desc_ready = false;
292 missing_funcs++;
293
294 if (gfs_registered)
295 usb_composite_unregister(&gfs_driver);
296 gfs_registered = false;
297
298done:
299 mutex_unlock(&gfs_lock);
300}
301
302static void *functionfs_acquire_dev_callback(const char *dev_name)
303{
304 struct gfs_ffs_obj *ffs_dev;
305
306 ENTER();
307 mutex_lock(&gfs_lock);
308
309 ffs_dev = gfs_find_dev(dev_name);
310 if (!ffs_dev) {
311 ffs_dev = ERR_PTR(-ENODEV);
312 goto done;
313 }
314
315 if (ffs_dev->mounted) {
316 ffs_dev = ERR_PTR(-EBUSY);
317 goto done;
318 }
319 ffs_dev->mounted = true;
320
321done:
322 mutex_unlock(&gfs_lock);
323 return ffs_dev;
324}
325
326static void functionfs_release_dev_callback(struct ffs_data *ffs_data)
327{
328 struct gfs_ffs_obj *ffs_dev;
329
330 ENTER();
331 mutex_lock(&gfs_lock);
332
333 ffs_dev = ffs_data->private_data;
334 if (ffs_dev)
335 ffs_dev->mounted = false;
336
337 mutex_unlock(&gfs_lock);
338}
339
340/*
341 * It is assumed that gfs_bind is called from a context where gfs_lock is held
342 */
343static int gfs_bind(struct usb_composite_dev *cdev)
344{
345 int ret, i;
346
347 ENTER();
348
349 if (missing_funcs)
350 return -ENODEV;
351
352 ret = gether_setup(cdev->gadget, gfs_hostaddr);
353 if (unlikely(ret < 0))
354 goto error_quick;
355 gfs_ether_setup = true;
356
357 ret = usb_string_ids_tab(cdev, gfs_strings);
358 if (unlikely(ret < 0))
359 goto error;
360
361 for (i = func_num; --i; ) {
362 ret = functionfs_bind(ffs_tab[i].ffs_data, cdev);
363 if (unlikely(ret < 0)) {
364 while (++i < func_num)
365 functionfs_unbind(ffs_tab[i].ffs_data);
366 goto error;
367 }
368 }
369
370 for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
371 struct gfs_configuration *c = gfs_configurations + i;
372
373 c->c.label = gfs_strings[i].s;
374 c->c.iConfiguration = gfs_strings[i].id;
375 c->c.bConfigurationValue = 1 + i;
376 c->c.bmAttributes = USB_CONFIG_ATT_SELFPOWER;
377
378 ret = usb_add_config(cdev, &c->c, gfs_do_config);
379 if (unlikely(ret < 0))
380 goto error_unbind;
381 }
382
383 return 0;
384
385error_unbind:
386 for (i = 0; i < func_num; i++)
387 functionfs_unbind(ffs_tab[i].ffs_data);
388error:
389 gether_cleanup();
390error_quick:
391 gfs_ether_setup = false;
392 return ret;
393}
394
395/*
396 * It is assumed that gfs_unbind is called from a context where gfs_lock is held
397 */
398static int gfs_unbind(struct usb_composite_dev *cdev)
399{
400 int i;
401
402 ENTER();
403
404 /*
405 * We may have been called in an error recovery from
406 * composite_bind() after gfs_unbind() failure so we need to
407 * check if gfs_ffs_data is not NULL since gfs_bind() handles
408 * all error recovery itself. I'd rather we werent called
409 * from composite on orror recovery, but what you're gonna
410 * do...?
411 */
412 if (gfs_ether_setup)
413 gether_cleanup();
414 gfs_ether_setup = false;
415
416 for (i = func_num; --i; )
417 if (ffs_tab[i].ffs_data)
418 functionfs_unbind(ffs_tab[i].ffs_data);
419
420 return 0;
421}
422
423/*
424 * It is assumed that gfs_do_config is called from a context where
425 * gfs_lock is held
426 */
427static int gfs_do_config(struct usb_configuration *c)
428{
429 struct gfs_configuration *gc =
430 container_of(c, struct gfs_configuration, c);
431 int i;
432 int ret;
433
434 if (missing_funcs)
435 return -ENODEV;
436
437 if (gadget_is_otg(c->cdev->gadget)) {
438 c->descriptors = gfs_otg_desc;
439 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
440 }
441
442 if (gc->eth) {
443 ret = gc->eth(c, gfs_hostaddr);
444 if (unlikely(ret < 0))
445 return ret;
446 }
447
448 for (i = 0; i < func_num; i++) {
449 ret = functionfs_bind_config(c->cdev, c, ffs_tab[i].ffs_data);
450 if (unlikely(ret < 0))
451 return ret;
452 }
453
454 /*
455 * After previous do_configs there may be some invalid
456 * pointers in c->interface array. This happens every time
457 * a user space function with fewer interfaces than a user
458 * space function that was run before the new one is run. The
459 * compasit's set_config() assumes that if there is no more
460 * then MAX_CONFIG_INTERFACES interfaces in a configuration
461 * then there is a NULL pointer after the last interface in
462 * c->interface array. We need to make sure this is true.
463 */
464 if (c->next_interface_id < ARRAY_SIZE(c->interface))
465 c->interface[c->next_interface_id] = NULL;
466
467 return 0;
468}
469
470#ifdef CONFIG_USB_FUNCTIONFS_ETH
471
472static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
473{
474 return can_support_ecm(c->cdev->gadget)
475 ? ecm_bind_config(c, ethaddr)
476 : geth_bind_config(c, ethaddr);
477}
478
479#endif