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1 /*
2 * file.c - part of debugfs, a tiny little debug file system
3 *
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * debugfs is for people to use instead of /proc or /sys.
12 * See Documentation/DocBook/filesystems for more details.
13 *
14 */
15
16 #include <linux/module.h>
17 #include <linux/fs.h>
18 #include <linux/seq_file.h>
19 #include <linux/pagemap.h>
20 #include <linux/namei.h>
21 #include <linux/debugfs.h>
22 #include <linux/io.h>
23
24 static ssize_t default_read_file(struct file *file, char __user *buf,
25 size_t count, loff_t *ppos)
26 {
27 return 0;
28 }
29
30 static ssize_t default_write_file(struct file *file, const char __user *buf,
31 size_t count, loff_t *ppos)
32 {
33 return count;
34 }
35
36 const struct file_operations debugfs_file_operations = {
37 .read = default_read_file,
38 .write = default_write_file,
39 .open = simple_open,
40 .llseek = noop_llseek,
41 };
42
43 static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
44 {
45 nd_set_link(nd, dentry->d_inode->i_private);
46 return NULL;
47 }
48
49 const struct inode_operations debugfs_link_operations = {
50 .readlink = generic_readlink,
51 .follow_link = debugfs_follow_link,
52 };
53
54 static int debugfs_u8_set(void *data, u64 val)
55 {
56 *(u8 *)data = val;
57 return 0;
58 }
59 static int debugfs_u8_get(void *data, u64 *val)
60 {
61 *val = *(u8 *)data;
62 return 0;
63 }
64 DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
65 DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
66 DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
67
68 /**
69 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
70 * @name: a pointer to a string containing the name of the file to create.
71 * @mode: the permission that the file should have
72 * @parent: a pointer to the parent dentry for this file. This should be a
73 * directory dentry if set. If this parameter is %NULL, then the
74 * file will be created in the root of the debugfs filesystem.
75 * @value: a pointer to the variable that the file should read to and write
76 * from.
77 *
78 * This function creates a file in debugfs with the given name that
79 * contains the value of the variable @value. If the @mode variable is so
80 * set, it can be read from, and written to.
81 *
82 * This function will return a pointer to a dentry if it succeeds. This
83 * pointer must be passed to the debugfs_remove() function when the file is
84 * to be removed (no automatic cleanup happens if your module is unloaded,
85 * you are responsible here.) If an error occurs, %NULL will be returned.
86 *
87 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
88 * returned. It is not wise to check for this value, but rather, check for
89 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
90 * code.
91 */
92 struct dentry *debugfs_create_u8(const char *name, umode_t mode,
93 struct dentry *parent, u8 *value)
94 {
95 /* if there are no write bits set, make read only */
96 if (!(mode & S_IWUGO))
97 return debugfs_create_file(name, mode, parent, value, &fops_u8_ro);
98 /* if there are no read bits set, make write only */
99 if (!(mode & S_IRUGO))
100 return debugfs_create_file(name, mode, parent, value, &fops_u8_wo);
101
102 return debugfs_create_file(name, mode, parent, value, &fops_u8);
103 }
104 EXPORT_SYMBOL_GPL(debugfs_create_u8);
105
106 static int debugfs_u16_set(void *data, u64 val)
107 {
108 *(u16 *)data = val;
109 return 0;
110 }
111 static int debugfs_u16_get(void *data, u64 *val)
112 {
113 *val = *(u16 *)data;
114 return 0;
115 }
116 DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
117 DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
118 DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
119
120 /**
121 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
122 * @name: a pointer to a string containing the name of the file to create.
123 * @mode: the permission that the file should have
124 * @parent: a pointer to the parent dentry for this file. This should be a
125 * directory dentry if set. If this parameter is %NULL, then the
126 * file will be created in the root of the debugfs filesystem.
127 * @value: a pointer to the variable that the file should read to and write
128 * from.
129 *
130 * This function creates a file in debugfs with the given name that
131 * contains the value of the variable @value. If the @mode variable is so
132 * set, it can be read from, and written to.
133 *
134 * This function will return a pointer to a dentry if it succeeds. This
135 * pointer must be passed to the debugfs_remove() function when the file is
136 * to be removed (no automatic cleanup happens if your module is unloaded,
137 * you are responsible here.) If an error occurs, %NULL will be returned.
138 *
139 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
140 * returned. It is not wise to check for this value, but rather, check for
141 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
142 * code.
143 */
144 struct dentry *debugfs_create_u16(const char *name, umode_t mode,
145 struct dentry *parent, u16 *value)
146 {
147 /* if there are no write bits set, make read only */
148 if (!(mode & S_IWUGO))
149 return debugfs_create_file(name, mode, parent, value, &fops_u16_ro);
150 /* if there are no read bits set, make write only */
151 if (!(mode & S_IRUGO))
152 return debugfs_create_file(name, mode, parent, value, &fops_u16_wo);
153
154 return debugfs_create_file(name, mode, parent, value, &fops_u16);
155 }
156 EXPORT_SYMBOL_GPL(debugfs_create_u16);
157
158 static int debugfs_u32_set(void *data, u64 val)
159 {
160 *(u32 *)data = val;
161 return 0;
162 }
163 static int debugfs_u32_get(void *data, u64 *val)
164 {
165 *val = *(u32 *)data;
166 return 0;
167 }
168 DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
169 DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
170 DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
171
172 /**
173 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
174 * @name: a pointer to a string containing the name of the file to create.
175 * @mode: the permission that the file should have
176 * @parent: a pointer to the parent dentry for this file. This should be a
177 * directory dentry if set. If this parameter is %NULL, then the
178 * file will be created in the root of the debugfs filesystem.
179 * @value: a pointer to the variable that the file should read to and write
180 * from.
181 *
182 * This function creates a file in debugfs with the given name that
183 * contains the value of the variable @value. If the @mode variable is so
184 * set, it can be read from, and written to.
185 *
186 * This function will return a pointer to a dentry if it succeeds. This
187 * pointer must be passed to the debugfs_remove() function when the file is
188 * to be removed (no automatic cleanup happens if your module is unloaded,
189 * you are responsible here.) If an error occurs, %NULL will be returned.
190 *
191 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
192 * returned. It is not wise to check for this value, but rather, check for
193 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
194 * code.
195 */
196 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
197 struct dentry *parent, u32 *value)
198 {
199 /* if there are no write bits set, make read only */
200 if (!(mode & S_IWUGO))
201 return debugfs_create_file(name, mode, parent, value, &fops_u32_ro);
202 /* if there are no read bits set, make write only */
203 if (!(mode & S_IRUGO))
204 return debugfs_create_file(name, mode, parent, value, &fops_u32_wo);
205
206 return debugfs_create_file(name, mode, parent, value, &fops_u32);
207 }
208 EXPORT_SYMBOL_GPL(debugfs_create_u32);
209
210 static int debugfs_u64_set(void *data, u64 val)
211 {
212 *(u64 *)data = val;
213 return 0;
214 }
215
216 static int debugfs_u64_get(void *data, u64 *val)
217 {
218 *val = *(u64 *)data;
219 return 0;
220 }
221 DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
222 DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
223 DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
224
225 /**
226 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
227 * @name: a pointer to a string containing the name of the file to create.
228 * @mode: the permission that the file should have
229 * @parent: a pointer to the parent dentry for this file. This should be a
230 * directory dentry if set. If this parameter is %NULL, then the
231 * file will be created in the root of the debugfs filesystem.
232 * @value: a pointer to the variable that the file should read to and write
233 * from.
234 *
235 * This function creates a file in debugfs with the given name that
236 * contains the value of the variable @value. If the @mode variable is so
237 * set, it can be read from, and written to.
238 *
239 * This function will return a pointer to a dentry if it succeeds. This
240 * pointer must be passed to the debugfs_remove() function when the file is
241 * to be removed (no automatic cleanup happens if your module is unloaded,
242 * you are responsible here.) If an error occurs, %NULL will be returned.
243 *
244 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
245 * returned. It is not wise to check for this value, but rather, check for
246 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
247 * code.
248 */
249 struct dentry *debugfs_create_u64(const char *name, umode_t mode,
250 struct dentry *parent, u64 *value)
251 {
252 /* if there are no write bits set, make read only */
253 if (!(mode & S_IWUGO))
254 return debugfs_create_file(name, mode, parent, value, &fops_u64_ro);
255 /* if there are no read bits set, make write only */
256 if (!(mode & S_IRUGO))
257 return debugfs_create_file(name, mode, parent, value, &fops_u64_wo);
258
259 return debugfs_create_file(name, mode, parent, value, &fops_u64);
260 }
261 EXPORT_SYMBOL_GPL(debugfs_create_u64);
262
263 DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
264 DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
265 DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
266
267 DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n");
268 DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
269 DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
270
271 DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n");
272 DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
273 DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
274
275 DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n");
276
277 /*
278 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
279 *
280 * These functions are exactly the same as the above functions (but use a hex
281 * output for the decimal challenged). For details look at the above unsigned
282 * decimal functions.
283 */
284
285 /**
286 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
287 * @name: a pointer to a string containing the name of the file to create.
288 * @mode: the permission that the file should have
289 * @parent: a pointer to the parent dentry for this file. This should be a
290 * directory dentry if set. If this parameter is %NULL, then the
291 * file will be created in the root of the debugfs filesystem.
292 * @value: a pointer to the variable that the file should read to and write
293 * from.
294 */
295 struct dentry *debugfs_create_x8(const char *name, umode_t mode,
296 struct dentry *parent, u8 *value)
297 {
298 /* if there are no write bits set, make read only */
299 if (!(mode & S_IWUGO))
300 return debugfs_create_file(name, mode, parent, value, &fops_x8_ro);
301 /* if there are no read bits set, make write only */
302 if (!(mode & S_IRUGO))
303 return debugfs_create_file(name, mode, parent, value, &fops_x8_wo);
304
305 return debugfs_create_file(name, mode, parent, value, &fops_x8);
306 }
307 EXPORT_SYMBOL_GPL(debugfs_create_x8);
308
309 /**
310 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
311 * @name: a pointer to a string containing the name of the file to create.
312 * @mode: the permission that the file should have
313 * @parent: a pointer to the parent dentry for this file. This should be a
314 * directory dentry if set. If this parameter is %NULL, then the
315 * file will be created in the root of the debugfs filesystem.
316 * @value: a pointer to the variable that the file should read to and write
317 * from.
318 */
319 struct dentry *debugfs_create_x16(const char *name, umode_t mode,
320 struct dentry *parent, u16 *value)
321 {
322 /* if there are no write bits set, make read only */
323 if (!(mode & S_IWUGO))
324 return debugfs_create_file(name, mode, parent, value, &fops_x16_ro);
325 /* if there are no read bits set, make write only */
326 if (!(mode & S_IRUGO))
327 return debugfs_create_file(name, mode, parent, value, &fops_x16_wo);
328
329 return debugfs_create_file(name, mode, parent, value, &fops_x16);
330 }
331 EXPORT_SYMBOL_GPL(debugfs_create_x16);
332
333 /**
334 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
335 * @name: a pointer to a string containing the name of the file to create.
336 * @mode: the permission that the file should have
337 * @parent: a pointer to the parent dentry for this file. This should be a
338 * directory dentry if set. If this parameter is %NULL, then the
339 * file will be created in the root of the debugfs filesystem.
340 * @value: a pointer to the variable that the file should read to and write
341 * from.
342 */
343 struct dentry *debugfs_create_x32(const char *name, umode_t mode,
344 struct dentry *parent, u32 *value)
345 {
346 /* if there are no write bits set, make read only */
347 if (!(mode & S_IWUGO))
348 return debugfs_create_file(name, mode, parent, value, &fops_x32_ro);
349 /* if there are no read bits set, make write only */
350 if (!(mode & S_IRUGO))
351 return debugfs_create_file(name, mode, parent, value, &fops_x32_wo);
352
353 return debugfs_create_file(name, mode, parent, value, &fops_x32);
354 }
355 EXPORT_SYMBOL_GPL(debugfs_create_x32);
356
357 /**
358 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
359 * @name: a pointer to a string containing the name of the file to create.
360 * @mode: the permission that the file should have
361 * @parent: a pointer to the parent dentry for this file. This should be a
362 * directory dentry if set. If this parameter is %NULL, then the
363 * file will be created in the root of the debugfs filesystem.
364 * @value: a pointer to the variable that the file should read to and write
365 * from.
366 */
367 struct dentry *debugfs_create_x64(const char *name, umode_t mode,
368 struct dentry *parent, u64 *value)
369 {
370 return debugfs_create_file(name, mode, parent, value, &fops_x64);
371 }
372 EXPORT_SYMBOL_GPL(debugfs_create_x64);
373
374
375 static int debugfs_size_t_set(void *data, u64 val)
376 {
377 *(size_t *)data = val;
378 return 0;
379 }
380 static int debugfs_size_t_get(void *data, u64 *val)
381 {
382 *val = *(size_t *)data;
383 return 0;
384 }
385 DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
386 "%llu\n"); /* %llu and %zu are more or less the same */
387
388 /**
389 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
390 * @name: a pointer to a string containing the name of the file to create.
391 * @mode: the permission that the file should have
392 * @parent: a pointer to the parent dentry for this file. This should be a
393 * directory dentry if set. If this parameter is %NULL, then the
394 * file will be created in the root of the debugfs filesystem.
395 * @value: a pointer to the variable that the file should read to and write
396 * from.
397 */
398 struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
399 struct dentry *parent, size_t *value)
400 {
401 return debugfs_create_file(name, mode, parent, value, &fops_size_t);
402 }
403 EXPORT_SYMBOL_GPL(debugfs_create_size_t);
404
405
406 static ssize_t read_file_bool(struct file *file, char __user *user_buf,
407 size_t count, loff_t *ppos)
408 {
409 char buf[3];
410 u32 *val = file->private_data;
411
412 if (*val)
413 buf[0] = 'Y';
414 else
415 buf[0] = 'N';
416 buf[1] = '\n';
417 buf[2] = 0x00;
418 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
419 }
420
421 static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
422 size_t count, loff_t *ppos)
423 {
424 char buf[32];
425 size_t buf_size;
426 bool bv;
427 u32 *val = file->private_data;
428
429 buf_size = min(count, (sizeof(buf)-1));
430 if (copy_from_user(buf, user_buf, buf_size))
431 return -EFAULT;
432
433 if (strtobool(buf, &bv) == 0)
434 *val = bv;
435
436 return count;
437 }
438
439 static const struct file_operations fops_bool = {
440 .read = read_file_bool,
441 .write = write_file_bool,
442 .open = simple_open,
443 .llseek = default_llseek,
444 };
445
446 /**
447 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
448 * @name: a pointer to a string containing the name of the file to create.
449 * @mode: the permission that the file should have
450 * @parent: a pointer to the parent dentry for this file. This should be a
451 * directory dentry if set. If this parameter is %NULL, then the
452 * file will be created in the root of the debugfs filesystem.
453 * @value: a pointer to the variable that the file should read to and write
454 * from.
455 *
456 * This function creates a file in debugfs with the given name that
457 * contains the value of the variable @value. If the @mode variable is so
458 * set, it can be read from, and written to.
459 *
460 * This function will return a pointer to a dentry if it succeeds. This
461 * pointer must be passed to the debugfs_remove() function when the file is
462 * to be removed (no automatic cleanup happens if your module is unloaded,
463 * you are responsible here.) If an error occurs, %NULL will be returned.
464 *
465 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
466 * returned. It is not wise to check for this value, but rather, check for
467 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
468 * code.
469 */
470 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
471 struct dentry *parent, u32 *value)
472 {
473 return debugfs_create_file(name, mode, parent, value, &fops_bool);
474 }
475 EXPORT_SYMBOL_GPL(debugfs_create_bool);
476
477 static ssize_t read_file_blob(struct file *file, char __user *user_buf,
478 size_t count, loff_t *ppos)
479 {
480 struct debugfs_blob_wrapper *blob = file->private_data;
481 return simple_read_from_buffer(user_buf, count, ppos, blob->data,
482 blob->size);
483 }
484
485 static const struct file_operations fops_blob = {
486 .read = read_file_blob,
487 .open = simple_open,
488 .llseek = default_llseek,
489 };
490
491 /**
492 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
493 * @name: a pointer to a string containing the name of the file to create.
494 * @mode: the permission that the file should have
495 * @parent: a pointer to the parent dentry for this file. This should be a
496 * directory dentry if set. If this parameter is %NULL, then the
497 * file will be created in the root of the debugfs filesystem.
498 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
499 * to the blob data and the size of the data.
500 *
501 * This function creates a file in debugfs with the given name that exports
502 * @blob->data as a binary blob. If the @mode variable is so set it can be
503 * read from. Writing is not supported.
504 *
505 * This function will return a pointer to a dentry if it succeeds. This
506 * pointer must be passed to the debugfs_remove() function when the file is
507 * to be removed (no automatic cleanup happens if your module is unloaded,
508 * you are responsible here.) If an error occurs, %NULL will be returned.
509 *
510 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
511 * returned. It is not wise to check for this value, but rather, check for
512 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
513 * code.
514 */
515 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
516 struct dentry *parent,
517 struct debugfs_blob_wrapper *blob)
518 {
519 return debugfs_create_file(name, mode, parent, blob, &fops_blob);
520 }
521 EXPORT_SYMBOL_GPL(debugfs_create_blob);
522
523 #ifdef CONFIG_HAS_IOMEM
524
525 /*
526 * The regset32 stuff is used to print 32-bit registers using the
527 * seq_file utilities. We offer printing a register set in an already-opened
528 * sequential file or create a debugfs file that only prints a regset32.
529 */
530
531 /**
532 * debugfs_print_regs32 - use seq_print to describe a set of registers
533 * @s: the seq_file structure being used to generate output
534 * @regs: an array if struct debugfs_reg32 structures
535 * @nregs: the length of the above array
536 * @base: the base address to be used in reading the registers
537 * @prefix: a string to be prefixed to every output line
538 *
539 * This function outputs a text block describing the current values of
540 * some 32-bit hardware registers. It is meant to be used within debugfs
541 * files based on seq_file that need to show registers, intermixed with other
542 * information. The prefix argument may be used to specify a leading string,
543 * because some peripherals have several blocks of identical registers,
544 * for example configuration of dma channels
545 */
546 int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
547 int nregs, void __iomem *base, char *prefix)
548 {
549 int i, ret = 0;
550
551 for (i = 0; i < nregs; i++, regs++) {
552 if (prefix)
553 ret += seq_printf(s, "%s", prefix);
554 ret += seq_printf(s, "%s = 0x%08x\n", regs->name,
555 readl(base + regs->offset));
556 }
557 return ret;
558 }
559 EXPORT_SYMBOL_GPL(debugfs_print_regs32);
560
561 static int debugfs_show_regset32(struct seq_file *s, void *data)
562 {
563 struct debugfs_regset32 *regset = s->private;
564
565 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
566 return 0;
567 }
568
569 static int debugfs_open_regset32(struct inode *inode, struct file *file)
570 {
571 return single_open(file, debugfs_show_regset32, inode->i_private);
572 }
573
574 static const struct file_operations fops_regset32 = {
575 .open = debugfs_open_regset32,
576 .read = seq_read,
577 .llseek = seq_lseek,
578 .release = single_release,
579 };
580
581 /**
582 * debugfs_create_regset32 - create a debugfs file that returns register values
583 * @name: a pointer to a string containing the name of the file to create.
584 * @mode: the permission that the file should have
585 * @parent: a pointer to the parent dentry for this file. This should be a
586 * directory dentry if set. If this parameter is %NULL, then the
587 * file will be created in the root of the debugfs filesystem.
588 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
589 * to an array of register definitions, the array size and the base
590 * address where the register bank is to be found.
591 *
592 * This function creates a file in debugfs with the given name that reports
593 * the names and values of a set of 32-bit registers. If the @mode variable
594 * is so set it can be read from. Writing is not supported.
595 *
596 * This function will return a pointer to a dentry if it succeeds. This
597 * pointer must be passed to the debugfs_remove() function when the file is
598 * to be removed (no automatic cleanup happens if your module is unloaded,
599 * you are responsible here.) If an error occurs, %NULL will be returned.
600 *
601 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
602 * returned. It is not wise to check for this value, but rather, check for
603 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
604 * code.
605 */
606 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
607 struct dentry *parent,
608 struct debugfs_regset32 *regset)
609 {
610 return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
611 }
612 EXPORT_SYMBOL_GPL(debugfs_create_regset32);
613
614 #endif /* CONFIG_HAS_IOMEM */