1/*
2 * $Id: chipreg.c,v 1.1.1.1 2007/08/03 18:52:43 Exp $
3 *
4 * Registration for chip drivers
5 *
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/kmod.h>
11#include <linux/spinlock.h>
12#include <linux/slab.h>
13#include <linux/mtd/map.h>
14#include <linux/mtd/mtd.h>
15#include <linux/mtd/compatmac.h>
16
17static DEFINE_SPINLOCK(chip_drvs_lock);
18static LIST_HEAD(chip_drvs_list);
19
20void register_mtd_chip_driver(struct mtd_chip_driver *drv)
21{
22	spin_lock(&chip_drvs_lock);
23	list_add(&drv->list, &chip_drvs_list);
24	spin_unlock(&chip_drvs_lock);
25}
26
27void unregister_mtd_chip_driver(struct mtd_chip_driver *drv)
28{
29	spin_lock(&chip_drvs_lock);
30	list_del(&drv->list);
31	spin_unlock(&chip_drvs_lock);
32}
33
34static struct mtd_chip_driver *get_mtd_chip_driver (const char *name)
35{
36	struct list_head *pos;
37	struct mtd_chip_driver *ret = NULL, *this;
38
39	spin_lock(&chip_drvs_lock);
40
41	list_for_each(pos, &chip_drvs_list) {
42		this = list_entry(pos, typeof(*this), list);
43
44		if (!strcmp(this->name, name)) {
45			ret = this;
46			break;
47		}
48	}
49	if (ret && !try_module_get(ret->module))
50		ret = NULL;
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(const 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("%s", name))
68		drv = get_mtd_chip_driver(name);
69
70	if (!drv)
71		return NULL;
72
73	ret = drv->probe(map);
74
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	module_put(drv->module);
81
82	if (ret)
83		return ret;
84
85	return NULL;
86}
87/*
88 * Destroy an MTD device which was created for a map device.
89 * Make sure the MTD device is already unregistered before calling this
90 */
91void map_destroy(struct mtd_info *mtd)
92{
93	struct map_info *map = mtd->priv;
94
95	if (map->fldrv->destroy)
96		map->fldrv->destroy(mtd);
97
98	module_put(map->fldrv->module);
99
100	kfree(mtd);
101}
102
103EXPORT_SYMBOL(register_mtd_chip_driver);
104EXPORT_SYMBOL(unregister_mtd_chip_driver);
105EXPORT_SYMBOL(do_map_probe);
106EXPORT_SYMBOL(map_destroy);
107
108MODULE_LICENSE("GPL");
109MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
110MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers");
111