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(n: func_num * N_CONF, size: 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(n: func_num, size: 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(name: "ffs");
207 if (IS_ERR(ptr: fi_ffs[i])) {
208 ret = PTR_ERR(ptr: fi_ffs[i]);
209 --i;
210 goto no_dev;
211 }
212 opts = to_f_fs_opts(fi: fi_ffs[i]);
213 if (gfs_single_func)
214 ret = ffs_single_dev(dev: opts->dev);
215 else
216 ret = ffs_name_dev(dev: opts->dev, name: 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: fi_ffs[i--]);
232 kfree(objp: fi_ffs);
233no_func:
234 kfree(objp: 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(driver: &gfs_driver);
245 gfs_registered = false;
246
247 kfree(objp: f_ffs[0]);
248
249 for (i = 0; i < func_num; i++)
250 usb_put_function_instance(fi: fi_ffs[i]);
251
252 kfree(objp: 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(error: -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(driver: &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(driver: &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(gadget: cdev->gadget)) {
319 struct f_ecm_opts *ecm_opts;
320
321 fi_ecm = usb_get_function_instance(name: "ecm");
322 if (IS_ERR(ptr: fi_ecm))
323 return PTR_ERR(ptr: 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(name: "geth");
330 if (IS_ERR(ptr: fi_geth))
331 return PTR_ERR(ptr: 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(name: "rndis");
341 if (IS_ERR(ptr: fi_rndis)) {
342 ret = PTR_ERR(ptr: 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, g: cdev->gadget);
362 ret = gether_register_netdev(net);
363 if (ret)
364 goto error_rndis;
365
366 if (can_support_ecm(gadget: 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(f: fi_rndis, net);
380#endif
381
382 /* TODO: gstrings_attach? */
383 ret = usb_string_ids_tab(c: cdev, str: 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(g: cdev->gadget) && !gfs_otg_desc[0]) {
389 struct usb_descriptor_header *usb_desc;
390
391 usb_desc = usb_otg_descriptor_alloc(gadget: cdev->gadget);
392 if (!usb_desc) {
393 ret = -ENOMEM;
394 goto error_rndis;
395 }
396 usb_otg_descriptor_init(gadget: cdev->gadget, otg_desc: 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, covr: &coverwrite);
417 return 0;
418
419/* TODO */
420error_unbind:
421 kfree(objp: gfs_otg_desc[0]);
422 gfs_otg_desc[0] = NULL;
423error_rndis:
424#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
425 usb_put_function_instance(fi: fi_rndis);
426error:
427#endif
428#if defined CONFIG_USB_FUNCTIONFS_ETH
429 if (can_support_ecm(gadget: cdev->gadget))
430 usb_put_function_instance(fi: fi_ecm);
431 else
432 usb_put_function_instance(fi: 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: f_rndis);
446 usb_put_function_instance(fi: fi_rndis);
447#endif
448
449#if defined CONFIG_USB_FUNCTIONFS_ETH
450 if (can_support_ecm(gadget: cdev->gadget)) {
451 usb_put_function(f: f_ecm);
452 usb_put_function_instance(fi: fi_ecm);
453 } else {
454 usb_put_function(f: f_geth);
455 usb_put_function_instance(fi: fi_geth);
456 }
457#endif
458 for (i = 0; i < N_CONF * func_num; ++i)
459 usb_put_function(f: *(f_ffs[0] + i));
460
461 kfree(objp: 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(g: 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: fi_ffs[i]);
494 if (IS_ERR(ptr: f_ffs[gc->num][i])) {
495 ret = PTR_ERR(ptr: 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: 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(ptr: f_ffs[gc->num][i]))
522 usb_remove_function(c, f: f_ffs[gc->num][i]);
523 usb_put_function(f: 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(gadget: c->cdev->gadget)) {
535 f_ecm = usb_get_function(fi: fi_ecm);
536 if (IS_ERR(ptr: f_ecm))
537 return PTR_ERR(ptr: f_ecm);
538
539 status = usb_add_function(c, f_ecm);
540 if (status < 0)
541 usb_put_function(f: f_ecm);
542
543 } else {
544 f_geth = usb_get_function(fi: fi_geth);
545 if (IS_ERR(ptr: f_geth))
546 return PTR_ERR(ptr: f_geth);
547
548 status = usb_add_function(c, f_geth);
549 if (status < 0)
550 usb_put_function(f: 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: fi_rndis);
564 if (IS_ERR(ptr: f_rndis))
565 return PTR_ERR(ptr: f_rndis);
566
567 status = usb_add_function(c, f_rndis);
568 if (status < 0)
569 usb_put_function(f: f_rndis);
570
571 return status;
572}
573
574#endif
575

source code of linux/drivers/usb/gadget/legacy/g_ffs.c