sound: oxygen: allow custom MCLK rates
[firewire-audio.git] / kernel / params.c
blob9da58eabdcb246dd3b156d7799ca49bf2799a304
1 /* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 #include <linux/moduleparam.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/module.h>
23 #include <linux/device.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
26 #include <linux/ctype.h>
28 #if 0
29 #define DEBUGP printk
30 #else
31 #define DEBUGP(fmt, a...)
32 #endif
34 static inline char dash2underscore(char c)
36 if (c == '-')
37 return '_';
38 return c;
41 static inline int parameq(const char *input, const char *paramname)
43 unsigned int i;
44 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
45 if (input[i] == '\0')
46 return 1;
47 return 0;
50 static int parse_one(char *param,
51 char *val,
52 struct kernel_param *params,
53 unsigned num_params,
54 int (*handle_unknown)(char *param, char *val))
56 unsigned int i;
58 /* Find parameter */
59 for (i = 0; i < num_params; i++) {
60 if (parameq(param, params[i].name)) {
61 DEBUGP("They are equal! Calling %p\n",
62 params[i].set);
63 return params[i].set(val, &params[i]);
67 if (handle_unknown) {
68 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
69 return handle_unknown(param, val);
72 DEBUGP("Unknown argument `%s'\n", param);
73 return -ENOENT;
76 /* You can use " around spaces, but can't escape ". */
77 /* Hyphens and underscores equivalent in parameter names. */
78 static char *next_arg(char *args, char **param, char **val)
80 unsigned int i, equals = 0;
81 int in_quote = 0, quoted = 0;
82 char *next;
84 if (*args == '"') {
85 args++;
86 in_quote = 1;
87 quoted = 1;
90 for (i = 0; args[i]; i++) {
91 if (isspace(args[i]) && !in_quote)
92 break;
93 if (equals == 0) {
94 if (args[i] == '=')
95 equals = i;
97 if (args[i] == '"')
98 in_quote = !in_quote;
101 *param = args;
102 if (!equals)
103 *val = NULL;
104 else {
105 args[equals] = '\0';
106 *val = args + equals + 1;
108 /* Don't include quotes in value. */
109 if (**val == '"') {
110 (*val)++;
111 if (args[i-1] == '"')
112 args[i-1] = '\0';
114 if (quoted && args[i-1] == '"')
115 args[i-1] = '\0';
118 if (args[i]) {
119 args[i] = '\0';
120 next = args + i + 1;
121 } else
122 next = args + i;
124 /* Chew up trailing spaces. */
125 while (isspace(*next))
126 next++;
127 return next;
130 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
131 int parse_args(const char *name,
132 char *args,
133 struct kernel_param *params,
134 unsigned num,
135 int (*unknown)(char *param, char *val))
137 char *param, *val;
139 DEBUGP("Parsing ARGS: %s\n", args);
141 /* Chew leading spaces */
142 while (isspace(*args))
143 args++;
145 while (*args) {
146 int ret;
147 int irq_was_disabled;
149 args = next_arg(args, &param, &val);
150 irq_was_disabled = irqs_disabled();
151 ret = parse_one(param, val, params, num, unknown);
152 if (irq_was_disabled && !irqs_disabled()) {
153 printk(KERN_WARNING "parse_args(): option '%s' enabled "
154 "irq's!\n", param);
156 switch (ret) {
157 case -ENOENT:
158 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
159 name, param);
160 return ret;
161 case -ENOSPC:
162 printk(KERN_ERR
163 "%s: `%s' too large for parameter `%s'\n",
164 name, val ?: "", param);
165 return ret;
166 case 0:
167 break;
168 default:
169 printk(KERN_ERR
170 "%s: `%s' invalid for parameter `%s'\n",
171 name, val ?: "", param);
172 return ret;
176 /* All parsed OK. */
177 return 0;
180 /* Lazy bastard, eh? */
181 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
182 int param_set_##name(const char *val, struct kernel_param *kp) \
184 tmptype l; \
185 int ret; \
187 if (!val) return -EINVAL; \
188 ret = strtolfn(val, 0, &l); \
189 if (ret == -EINVAL || ((type)l != l)) \
190 return -EINVAL; \
191 *((type *)kp->arg) = l; \
192 return 0; \
194 int param_get_##name(char *buffer, struct kernel_param *kp) \
196 return sprintf(buffer, format, *((type *)kp->arg)); \
199 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
200 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
201 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
202 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
203 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
204 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
205 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
207 int param_set_charp(const char *val, struct kernel_param *kp)
209 if (!val) {
210 printk(KERN_ERR "%s: string parameter expected\n",
211 kp->name);
212 return -EINVAL;
215 if (strlen(val) > 1024) {
216 printk(KERN_ERR "%s: string parameter too long\n",
217 kp->name);
218 return -ENOSPC;
221 if (kp->flags & KPARAM_KMALLOCED)
222 kfree(*(char **)kp->arg);
224 /* This is a hack. We can't need to strdup in early boot, and we
225 * don't need to; this mangled commandline is preserved. */
226 if (slab_is_available()) {
227 kp->flags |= KPARAM_KMALLOCED;
228 *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
229 if (!kp->arg)
230 return -ENOMEM;
231 } else
232 *(const char **)kp->arg = val;
234 return 0;
237 int param_get_charp(char *buffer, struct kernel_param *kp)
239 return sprintf(buffer, "%s", *((char **)kp->arg));
242 /* Actually could be a bool or an int, for historical reasons. */
243 int param_set_bool(const char *val, struct kernel_param *kp)
245 bool v;
247 /* No equals means "set"... */
248 if (!val) val = "1";
250 /* One of =[yYnN01] */
251 switch (val[0]) {
252 case 'y': case 'Y': case '1':
253 v = true;
254 break;
255 case 'n': case 'N': case '0':
256 v = false;
257 break;
258 default:
259 return -EINVAL;
262 if (kp->flags & KPARAM_ISBOOL)
263 *(bool *)kp->arg = v;
264 else
265 *(int *)kp->arg = v;
266 return 0;
269 int param_get_bool(char *buffer, struct kernel_param *kp)
271 bool val;
272 if (kp->flags & KPARAM_ISBOOL)
273 val = *(bool *)kp->arg;
274 else
275 val = *(int *)kp->arg;
277 /* Y and N chosen as being relatively non-coder friendly */
278 return sprintf(buffer, "%c", val ? 'Y' : 'N');
281 /* This one must be bool. */
282 int param_set_invbool(const char *val, struct kernel_param *kp)
284 int ret;
285 bool boolval;
286 struct kernel_param dummy;
288 dummy.arg = &boolval;
289 dummy.flags = KPARAM_ISBOOL;
290 ret = param_set_bool(val, &dummy);
291 if (ret == 0)
292 *(bool *)kp->arg = !boolval;
293 return ret;
296 int param_get_invbool(char *buffer, struct kernel_param *kp)
298 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
301 /* We break the rule and mangle the string. */
302 static int param_array(const char *name,
303 const char *val,
304 unsigned int min, unsigned int max,
305 void *elem, int elemsize,
306 int (*set)(const char *, struct kernel_param *kp),
307 unsigned int *num)
309 int ret;
310 struct kernel_param kp;
311 char save;
313 /* Get the name right for errors. */
314 kp.name = name;
315 kp.arg = elem;
317 /* No equals sign? */
318 if (!val) {
319 printk(KERN_ERR "%s: expects arguments\n", name);
320 return -EINVAL;
323 *num = 0;
324 /* We expect a comma-separated list of values. */
325 do {
326 int len;
328 if (*num == max) {
329 printk(KERN_ERR "%s: can only take %i arguments\n",
330 name, max);
331 return -EINVAL;
333 len = strcspn(val, ",");
335 /* nul-terminate and parse */
336 save = val[len];
337 ((char *)val)[len] = '\0';
338 ret = set(val, &kp);
340 if (ret != 0)
341 return ret;
342 kp.arg += elemsize;
343 val += len+1;
344 (*num)++;
345 } while (save == ',');
347 if (*num < min) {
348 printk(KERN_ERR "%s: needs at least %i arguments\n",
349 name, min);
350 return -EINVAL;
352 return 0;
355 int param_array_set(const char *val, struct kernel_param *kp)
357 const struct kparam_array *arr = kp->arr;
358 unsigned int temp_num;
360 return param_array(kp->name, val, 1, arr->max, arr->elem,
361 arr->elemsize, arr->set, arr->num ?: &temp_num);
364 int param_array_get(char *buffer, struct kernel_param *kp)
366 int i, off, ret;
367 const struct kparam_array *arr = kp->arr;
368 struct kernel_param p;
370 p = *kp;
371 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
372 if (i)
373 buffer[off++] = ',';
374 p.arg = arr->elem + arr->elemsize * i;
375 ret = arr->get(buffer + off, &p);
376 if (ret < 0)
377 return ret;
378 off += ret;
380 buffer[off] = '\0';
381 return off;
384 int param_set_copystring(const char *val, struct kernel_param *kp)
386 const struct kparam_string *kps = kp->str;
388 if (!val) {
389 printk(KERN_ERR "%s: missing param set value\n", kp->name);
390 return -EINVAL;
392 if (strlen(val)+1 > kps->maxlen) {
393 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
394 kp->name, kps->maxlen-1);
395 return -ENOSPC;
397 strcpy(kps->string, val);
398 return 0;
401 int param_get_string(char *buffer, struct kernel_param *kp)
403 const struct kparam_string *kps = kp->str;
404 return strlcpy(buffer, kps->string, kps->maxlen);
407 /* sysfs output in /sys/modules/XYZ/parameters/ */
408 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
409 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
411 extern struct kernel_param __start___param[], __stop___param[];
413 struct param_attribute
415 struct module_attribute mattr;
416 struct kernel_param *param;
419 struct module_param_attrs
421 unsigned int num;
422 struct attribute_group grp;
423 struct param_attribute attrs[0];
426 #ifdef CONFIG_SYSFS
427 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
429 static ssize_t param_attr_show(struct module_attribute *mattr,
430 struct module *mod, char *buf)
432 int count;
433 struct param_attribute *attribute = to_param_attr(mattr);
435 if (!attribute->param->get)
436 return -EPERM;
438 count = attribute->param->get(buf, attribute->param);
439 if (count > 0) {
440 strcat(buf, "\n");
441 ++count;
443 return count;
446 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
447 static ssize_t param_attr_store(struct module_attribute *mattr,
448 struct module *owner,
449 const char *buf, size_t len)
451 int err;
452 struct param_attribute *attribute = to_param_attr(mattr);
454 if (!attribute->param->set)
455 return -EPERM;
457 err = attribute->param->set(buf, attribute->param);
458 if (!err)
459 return len;
460 return err;
462 #endif
464 #ifdef CONFIG_MODULES
465 #define __modinit
466 #else
467 #define __modinit __init
468 #endif
470 #ifdef CONFIG_SYSFS
472 * add_sysfs_param - add a parameter to sysfs
473 * @mk: struct module_kobject
474 * @kparam: the actual parameter definition to add to sysfs
475 * @name: name of parameter
477 * Create a kobject if for a (per-module) parameter if mp NULL, and
478 * create file in sysfs. Returns an error on out of memory. Always cleans up
479 * if there's an error.
481 static __modinit int add_sysfs_param(struct module_kobject *mk,
482 struct kernel_param *kp,
483 const char *name)
485 struct module_param_attrs *new;
486 struct attribute **attrs;
487 int err, num;
489 /* We don't bother calling this with invisible parameters. */
490 BUG_ON(!kp->perm);
492 if (!mk->mp) {
493 num = 0;
494 attrs = NULL;
495 } else {
496 num = mk->mp->num;
497 attrs = mk->mp->grp.attrs;
500 /* Enlarge. */
501 new = krealloc(mk->mp,
502 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
503 GFP_KERNEL);
504 if (!new) {
505 kfree(mk->mp);
506 err = -ENOMEM;
507 goto fail;
509 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
510 if (!attrs) {
511 err = -ENOMEM;
512 goto fail_free_new;
515 /* Sysfs wants everything zeroed. */
516 memset(new, 0, sizeof(*new));
517 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
518 memset(&attrs[num], 0, sizeof(attrs[num]));
519 new->grp.name = "parameters";
520 new->grp.attrs = attrs;
522 /* Tack new one on the end. */
523 new->attrs[num].param = kp;
524 new->attrs[num].mattr.show = param_attr_show;
525 new->attrs[num].mattr.store = param_attr_store;
526 new->attrs[num].mattr.attr.name = (char *)name;
527 new->attrs[num].mattr.attr.mode = kp->perm;
528 new->num = num+1;
530 /* Fix up all the pointers, since krealloc can move us */
531 for (num = 0; num < new->num; num++)
532 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
533 new->grp.attrs[num] = NULL;
535 mk->mp = new;
536 return 0;
538 fail_free_new:
539 kfree(new);
540 fail:
541 mk->mp = NULL;
542 return err;
545 #ifdef CONFIG_MODULES
546 static void free_module_param_attrs(struct module_kobject *mk)
548 kfree(mk->mp->grp.attrs);
549 kfree(mk->mp);
550 mk->mp = NULL;
554 * module_param_sysfs_setup - setup sysfs support for one module
555 * @mod: module
556 * @kparam: module parameters (array)
557 * @num_params: number of module parameters
559 * Adds sysfs entries for module parameters under
560 * /sys/module/[mod->name]/parameters/
562 int module_param_sysfs_setup(struct module *mod,
563 struct kernel_param *kparam,
564 unsigned int num_params)
566 int i, err;
567 bool params = false;
569 for (i = 0; i < num_params; i++) {
570 if (kparam[i].perm == 0)
571 continue;
572 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
573 if (err)
574 return err;
575 params = true;
578 if (!params)
579 return 0;
581 /* Create the param group. */
582 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
583 if (err)
584 free_module_param_attrs(&mod->mkobj);
585 return err;
589 * module_param_sysfs_remove - remove sysfs support for one module
590 * @mod: module
592 * Remove sysfs entries for module parameters and the corresponding
593 * kobject.
595 void module_param_sysfs_remove(struct module *mod)
597 if (mod->mkobj.mp) {
598 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
599 /* We are positive that no one is using any param
600 * attrs at this point. Deallocate immediately. */
601 free_module_param_attrs(&mod->mkobj);
604 #endif
606 void destroy_params(const struct kernel_param *params, unsigned num)
608 unsigned int i;
610 for (i = 0; i < num; i++)
611 if (params[i].flags & KPARAM_KMALLOCED)
612 kfree(*(char **)params[i].arg);
615 static void __init kernel_add_sysfs_param(const char *name,
616 struct kernel_param *kparam,
617 unsigned int name_skip)
619 struct module_kobject *mk;
620 struct kobject *kobj;
621 int err;
623 kobj = kset_find_obj(module_kset, name);
624 if (kobj) {
625 /* We already have one. Remove params so we can add more. */
626 mk = to_module_kobject(kobj);
627 /* We need to remove it before adding parameters. */
628 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
629 } else {
630 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
631 BUG_ON(!mk);
633 mk->mod = THIS_MODULE;
634 mk->kobj.kset = module_kset;
635 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
636 "%s", name);
637 if (err) {
638 kobject_put(&mk->kobj);
639 printk(KERN_ERR "Module '%s' failed add to sysfs, "
640 "error number %d\n", name, err);
641 printk(KERN_ERR "The system will be unstable now.\n");
642 return;
644 /* So that exit path is even. */
645 kobject_get(&mk->kobj);
648 /* These should not fail at boot. */
649 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
650 BUG_ON(err);
651 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
652 BUG_ON(err);
653 kobject_uevent(&mk->kobj, KOBJ_ADD);
654 kobject_put(&mk->kobj);
658 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
660 * Add module_parameters to sysfs for "modules" built into the kernel.
662 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
663 * "parameter" name is stored behind a dot in kernel_param->name. So,
664 * extract the "module" name for all built-in kernel_param-eters,
665 * and for all who have the same, call kernel_add_sysfs_param.
667 static void __init param_sysfs_builtin(void)
669 struct kernel_param *kp;
670 unsigned int name_len;
671 char modname[MODULE_NAME_LEN];
673 for (kp = __start___param; kp < __stop___param; kp++) {
674 char *dot;
676 if (kp->perm == 0)
677 continue;
679 dot = strchr(kp->name, '.');
680 if (!dot) {
681 /* This happens for core_param() */
682 strcpy(modname, "kernel");
683 name_len = 0;
684 } else {
685 name_len = dot - kp->name + 1;
686 strlcpy(modname, kp->name, name_len);
688 kernel_add_sysfs_param(modname, kp, name_len);
693 /* module-related sysfs stuff */
695 static ssize_t module_attr_show(struct kobject *kobj,
696 struct attribute *attr,
697 char *buf)
699 struct module_attribute *attribute;
700 struct module_kobject *mk;
701 int ret;
703 attribute = to_module_attr(attr);
704 mk = to_module_kobject(kobj);
706 if (!attribute->show)
707 return -EIO;
709 ret = attribute->show(attribute, mk->mod, buf);
711 return ret;
714 static ssize_t module_attr_store(struct kobject *kobj,
715 struct attribute *attr,
716 const char *buf, size_t len)
718 struct module_attribute *attribute;
719 struct module_kobject *mk;
720 int ret;
722 attribute = to_module_attr(attr);
723 mk = to_module_kobject(kobj);
725 if (!attribute->store)
726 return -EIO;
728 ret = attribute->store(attribute, mk->mod, buf, len);
730 return ret;
733 static struct sysfs_ops module_sysfs_ops = {
734 .show = module_attr_show,
735 .store = module_attr_store,
738 static int uevent_filter(struct kset *kset, struct kobject *kobj)
740 struct kobj_type *ktype = get_ktype(kobj);
742 if (ktype == &module_ktype)
743 return 1;
744 return 0;
747 static struct kset_uevent_ops module_uevent_ops = {
748 .filter = uevent_filter,
751 struct kset *module_kset;
752 int module_sysfs_initialized;
754 struct kobj_type module_ktype = {
755 .sysfs_ops = &module_sysfs_ops,
759 * param_sysfs_init - wrapper for built-in params support
761 static int __init param_sysfs_init(void)
763 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
764 if (!module_kset) {
765 printk(KERN_WARNING "%s (%d): error creating kset\n",
766 __FILE__, __LINE__);
767 return -ENOMEM;
769 module_sysfs_initialized = 1;
771 param_sysfs_builtin();
773 return 0;
775 subsys_initcall(param_sysfs_init);
777 #endif /* CONFIG_SYSFS */
779 EXPORT_SYMBOL(param_set_byte);
780 EXPORT_SYMBOL(param_get_byte);
781 EXPORT_SYMBOL(param_set_short);
782 EXPORT_SYMBOL(param_get_short);
783 EXPORT_SYMBOL(param_set_ushort);
784 EXPORT_SYMBOL(param_get_ushort);
785 EXPORT_SYMBOL(param_set_int);
786 EXPORT_SYMBOL(param_get_int);
787 EXPORT_SYMBOL(param_set_uint);
788 EXPORT_SYMBOL(param_get_uint);
789 EXPORT_SYMBOL(param_set_long);
790 EXPORT_SYMBOL(param_get_long);
791 EXPORT_SYMBOL(param_set_ulong);
792 EXPORT_SYMBOL(param_get_ulong);
793 EXPORT_SYMBOL(param_set_charp);
794 EXPORT_SYMBOL(param_get_charp);
795 EXPORT_SYMBOL(param_set_bool);
796 EXPORT_SYMBOL(param_get_bool);
797 EXPORT_SYMBOL(param_set_invbool);
798 EXPORT_SYMBOL(param_get_invbool);
799 EXPORT_SYMBOL(param_array_set);
800 EXPORT_SYMBOL(param_array_get);
801 EXPORT_SYMBOL(param_set_copystring);
802 EXPORT_SYMBOL(param_get_string);