4 * Utility definitions for the FunctionFS
6 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
7 * http://www.samsung.com
9 * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
19 #include <linux/usb/composite.h>
20 #include <linux/list.h>
21 #include <linux/mutex.h>
25 # define pr_vdebug pr_debug
26 #endif /* pr_vdebug */
27 # define ffs_dump_mem(prefix, ptr, len) \
28 print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
31 # define pr_vdebug(...) do { } while (0)
32 #endif /* pr_vdebug */
33 # define ffs_dump_mem(prefix, ptr, len) do { } while (0)
34 #endif /* VERBOSE_DEBUG */
36 #define ENTER() pr_vdebug("%s()\n", __func__)
46 struct ffs_data *ffs_data;
47 struct f_fs_opts *opts;
48 struct list_head entry;
50 int (*ffs_ready_callback)(struct ffs_data *ffs);
51 void (*ffs_closed_callback)(struct ffs_data *ffs);
52 void *(*ffs_acquire_dev_callback)(struct ffs_dev *dev);
53 void (*ffs_release_dev_callback)(struct ffs_dev *dev);
56 extern struct mutex ffs_lock;
58 static inline void ffs_dev_lock(void)
60 mutex_lock(&ffs_lock);
63 static inline void ffs_dev_unlock(void)
65 mutex_unlock(&ffs_lock);
68 int ffs_name_dev(struct ffs_dev *dev, const char *name);
69 int ffs_single_dev(struct ffs_dev *dev);
76 * Waiting for descriptors and strings.
78 * In this state no open(2), read(2) or write(2) on epfiles
79 * may succeed (which should not be the problem as there
80 * should be no such files opened in the first place).
86 * We've got descriptors and strings. We are or have called
87 * functionfs_ready_callback(). functionfs_bind() may have
88 * been called but we don't know.
90 * This is the only state in which operations on epfiles may
96 * All endpoints have been closed. This state is also set if
97 * we encounter an unrecoverable error. The only
98 * unrecoverable error is situation when after reading strings
99 * from user space we fail to initialise epfiles or
100 * functionfs_ready_callback() returns with error (<0).
102 * In this state no open(2), read(2) or write(2) (both on ep0
103 * as well as epfile) may succeed (at this point epfiles are
104 * unlinked and all closed so this is not a problem; ep0 is
105 * also closed but ep0 file exists and so open(2) on ep0 must
111 enum ffs_setup_state {
112 /* There is no setup request pending. */
115 * User has read events and there was a setup request event
116 * there. The next read/write on ep0 will handle the
121 * There was event pending but before user space handled it
122 * some other event was introduced which canceled existing
123 * setup. If this state is set read/write on ep0 return
124 * -EIDRM. This state is only set when adding event.
130 struct usb_gadget *gadget;
133 * Protect access read/write operations, only one read/write
134 * at a time. As a consequence protects ep0req and company.
135 * While setup request is being processed (queued) this is
141 * Protect access to endpoint related structures (basically
142 * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
148 * XXX REVISIT do we need our own request? Since we are not
149 * handling setup requests immediately user space may be so
150 * slow that another setup will be sent to the gadget but this
151 * time not to us but another function and then there could be
152 * a race. Is that the case? Or maybe we can use cdev->req
153 * after all, maybe we just need some spinlock for that?
155 struct usb_request *ep0req; /* P: mutex */
156 struct completion ep0req_completion; /* P: mutex */
157 int ep0req_status; /* P: mutex */
159 /* reference counter */
161 /* how many files are opened (EP0 and others) */
165 enum ffs_state state;
168 * Possible transitions:
169 * + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
170 * happens only in ep0 read which is P: mutex
171 * + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
172 * happens only in ep0 i/o which is P: mutex
173 * + FFS_SETUP_PENDING -> FFS_SETUP_CANCELLED -- P: ev.waitq.lock
174 * + FFS_SETUP_CANCELLED -> FFS_NO_SETUP -- cmpxchg
176 * This field should never be accessed directly and instead
177 * ffs_setup_state_clear_cancelled function should be used.
179 enum ffs_setup_state setup_state;
184 unsigned short count;
185 /* XXX REVISIT need to update it in some places, or do we? */
186 unsigned short can_stall;
187 struct usb_ctrlrequest setup;
189 wait_queue_head_t waitq;
190 } ev; /* the whole structure, P: ev.waitq.lock */
194 #define FFS_FL_CALL_CLOSED_CALLBACK 0
195 #define FFS_FL_BOUND 1
197 /* Active function */
198 struct ffs_function *func;
201 * Device name, write once when file system is mounted.
202 * Intended for user to read if she wants.
204 const char *dev_name;
205 /* Private data for our user (ie. gadget). Managed by user. */
208 /* filled by __ffs_data_got_descs() */
210 * Real descriptors are 16 bytes after raw_descs (so you need
211 * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
212 * first full speed descriptor). raw_descs_length and
213 * raw_fs_descs_length do not have those 16 bytes added.
215 const void *raw_descs;
216 unsigned raw_descs_length;
217 unsigned raw_fs_descs_length;
218 unsigned fs_descs_count;
219 unsigned hs_descs_count;
221 unsigned short strings_count;
222 unsigned short interfaces_count;
223 unsigned short eps_count;
224 unsigned short _pad1;
226 /* filled by __ffs_data_got_strings() */
227 /* ids in stringtabs are set in functionfs_bind() */
228 const void *raw_strings;
229 struct usb_gadget_strings **stringtabs;
232 * File system's super block, write once when file system is
235 struct super_block *sb;
237 /* File permissions, written once when fs is mounted */
238 struct ffs_file_perms {
245 * The endpoint files, filled by ffs_epfiles_create(),
246 * destroyed by ffs_epfiles_destroy().
248 struct ffs_epfile *epfiles;
253 struct usb_function_instance func_inst;
259 static inline struct f_fs_opts *to_f_fs_opts(struct usb_function_instance *fi)
261 return container_of(fi, struct f_fs_opts, func_inst);