1/*
2 * $Id: chipreg.c,v 1.1.1.1 2008/10/15 03:26:35 james26_jang Exp $
3 *
4 * Registration for chip drivers
5 *
6 */
7
8#include <linux/kernel.h>
9#include <linux/config.h>
10#include <linux/kmod.h>
11#include <linux/spinlock.h>
12#include <linux/mtd/compatmac.h>
13#include <linux/mtd/map.h>
14
15spinlock_t chip_drvs_lock = SPIN_LOCK_UNLOCKED;
16static LIST_HEAD(chip_drvs_list);
17
18void register_mtd_chip_driver(struct mtd_chip_driver *drv)
19{
20	spin_lock(&chip_drvs_lock);
21	list_add(&drv->list, &chip_drvs_list);
22	spin_unlock(&chip_drvs_lock);
23}
24
25void unregister_mtd_chip_driver(struct mtd_chip_driver *drv)
26{
27	spin_lock(&chip_drvs_lock);
28	list_del(&drv->list);
29	spin_unlock(&chip_drvs_lock);
30}
31
32static struct mtd_chip_driver *get_mtd_chip_driver (char *name)
33{
34	struct list_head *pos;
35	struct mtd_chip_driver *ret = NULL, *this;
36
37	spin_lock(&chip_drvs_lock);
38
39	list_for_each(pos, &chip_drvs_list) {
40		this = list_entry(pos, typeof(*this), list);
41
42		if (!strcmp(this->name, name)) {
43			ret = this;
44			break;
45		}
46	}
47	if (ret && !try_inc_mod_count(ret->module)) {
48		/* Eep. Failed. */
49		ret = NULL;
50	}
51
52	spin_unlock(&chip_drvs_lock);
53
54	return ret;
55}
56
57	/* Hide all the horrid details, like some silly person taking
58	   get_module_symbol() away from us, from the caller. */
59
60struct mtd_info *do_map_probe(char *name, struct map_info *map)
61{
62	struct mtd_chip_driver *drv;
63	struct mtd_info *ret;
64
65	drv = get_mtd_chip_driver(name);
66
67	if (!drv && !request_module(name))
68		drv = get_mtd_chip_driver(name);
69
70	if (!drv)
71		return NULL;
72
73	ret = drv->probe(map);
74#ifdef CONFIG_MODULES
75	/* We decrease the use count here. It may have been a
76	   probe-only module, which is no longer required from this
77	   point, having given us a handle on (and increased the use
78	   count of) the actual driver code.
79	*/
80	if(drv->module)
81		__MOD_DEC_USE_COUNT(drv->module);
82#endif
83
84	if (ret)
85		return ret;
86
87	return NULL;
88}
89
90EXPORT_SYMBOL(register_mtd_chip_driver);
91EXPORT_SYMBOL(unregister_mtd_chip_driver);
92EXPORT_SYMBOL(do_map_probe);
93
94MODULE_LICENSE("GPL");
95MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
96MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers");
97