1/*
2 * Registration for chip drivers
3 *
4 */
5
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/kmod.h>
9#include <linux/spinlock.h>
10#include <linux/slab.h>
11#include <linux/mtd/map.h>
12#include <linux/mtd/mtd.h>
13
14static DEFINE_SPINLOCK(chip_drvs_lock);
15static LIST_HEAD(chip_drvs_list);
16
17void register_mtd_chip_driver(struct mtd_chip_driver *drv)
18{
19	spin_lock(&chip_drvs_lock);
20	list_add(&drv->list, &chip_drvs_list);
21	spin_unlock(&chip_drvs_lock);
22}
23
24void unregister_mtd_chip_driver(struct mtd_chip_driver *drv)
25{
26	spin_lock(&chip_drvs_lock);
27	list_del(&drv->list);
28	spin_unlock(&chip_drvs_lock);
29}
30
31static struct mtd_chip_driver *get_mtd_chip_driver (const char *name)
32{
33	struct list_head *pos;
34	struct mtd_chip_driver *ret = NULL, *this;
35
36	spin_lock(&chip_drvs_lock);
37
38	list_for_each(pos, &chip_drvs_list) {
39		this = list_entry(pos, typeof(*this), list);
40
41		if (!strcmp(this->name, name)) {
42			ret = this;
43			break;
44		}
45	}
46	if (ret && !try_module_get(ret->module))
47		ret = NULL;
48
49	spin_unlock(&chip_drvs_lock);
50
51	return ret;
52}
53
54	/* Hide all the horrid details, like some silly person taking
55	   get_module_symbol() away from us, from the caller. */
56
57struct mtd_info *do_map_probe(const char *name, struct map_info *map)
58{
59	struct mtd_chip_driver *drv;
60	struct mtd_info *ret;
61
62	drv = get_mtd_chip_driver(name);
63
64	if (!drv && !request_module("%s", name))
65		drv = get_mtd_chip_driver(name);
66
67	if (!drv)
68		return NULL;
69
70	ret = drv->probe(map);
71
72	/* We decrease the use count here. It may have been a
73	   probe-only module, which is no longer required from this
74	   point, having given us a handle on (and increased the use
75	   count of) the actual driver code.
76	*/
77	module_put(drv->module);
78
79	return ret;
80}
81/*
82 * Destroy an MTD device which was created for a map device.
83 * Make sure the MTD device is already unregistered before calling this
84 */
85void map_destroy(struct mtd_info *mtd)
86{
87	struct map_info *map = mtd->priv;
88
89	if (map->fldrv->destroy)
90		map->fldrv->destroy(mtd);
91
92	module_put(map->fldrv->module);
93
94	kfree(mtd);
95}
96
97EXPORT_SYMBOL(register_mtd_chip_driver);
98EXPORT_SYMBOL(unregister_mtd_chip_driver);
99EXPORT_SYMBOL(do_map_probe);
100EXPORT_SYMBOL(map_destroy);
101
102MODULE_LICENSE("GPL");
103MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
104MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers");
105