| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * $Id: chipreg.c,v 1.17 2004/11/16 18:29:00 dwmw2 Exp $ |
| 3 | * |
| 4 | * Registration for chip drivers |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <linux/kernel.h> |
| 9 | #include <linux/config.h> |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/kmod.h> |
| 12 | #include <linux/spinlock.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/mtd/map.h> |
| 15 | #include <linux/mtd/mtd.h> |
| 16 | #include <linux/mtd/compatmac.h> |
| 17 | |
| 18 | static DEFINE_SPINLOCK(chip_drvs_lock); |
| 19 | static LIST_HEAD(chip_drvs_list); |
| 20 | |
| 21 | void register_mtd_chip_driver(struct mtd_chip_driver *drv) |
| 22 | { |
| 23 | spin_lock(&chip_drvs_lock); |
| 24 | list_add(&drv->list, &chip_drvs_list); |
| 25 | spin_unlock(&chip_drvs_lock); |
| 26 | } |
| 27 | |
| 28 | void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) |
| 29 | { |
| 30 | spin_lock(&chip_drvs_lock); |
| 31 | list_del(&drv->list); |
| 32 | spin_unlock(&chip_drvs_lock); |
| 33 | } |
| 34 | |
| 35 | static struct mtd_chip_driver *get_mtd_chip_driver (const char *name) |
| 36 | { |
| 37 | struct list_head *pos; |
| 38 | struct mtd_chip_driver *ret = NULL, *this; |
| 39 | |
| 40 | spin_lock(&chip_drvs_lock); |
| 41 | |
| 42 | list_for_each(pos, &chip_drvs_list) { |
| 43 | this = list_entry(pos, typeof(*this), list); |
| 44 | |
| 45 | if (!strcmp(this->name, name)) { |
| 46 | ret = this; |
| 47 | break; |
| 48 | } |
| 49 | } |
| 50 | if (ret && !try_module_get(ret->module)) |
| 51 | ret = NULL; |
| 52 | |
| 53 | spin_unlock(&chip_drvs_lock); |
| 54 | |
| 55 | return ret; |
| 56 | } |
| 57 | |
| 58 | /* Hide all the horrid details, like some silly person taking |
| 59 | get_module_symbol() away from us, from the caller. */ |
| 60 | |
| 61 | struct mtd_info *do_map_probe(const char *name, struct map_info *map) |
| 62 | { |
| 63 | struct mtd_chip_driver *drv; |
| 64 | struct mtd_info *ret; |
| 65 | |
| 66 | drv = get_mtd_chip_driver(name); |
| 67 | |
| 68 | if (!drv && !request_module("%s", name)) |
| 69 | drv = get_mtd_chip_driver(name); |
| 70 | |
| 71 | if (!drv) |
| 72 | return NULL; |
| 73 | |
| 74 | ret = drv->probe(map); |
| 75 | |
| 76 | /* We decrease the use count here. It may have been a |
| 77 | probe-only module, which is no longer required from this |
| 78 | point, having given us a handle on (and increased the use |
| 79 | count of) the actual driver code. |
| 80 | */ |
| 81 | module_put(drv->module); |
| 82 | |
| 83 | if (ret) |
| 84 | return ret; |
| 85 | |
| 86 | return NULL; |
| 87 | } |
| 88 | /* |
| 89 | * Destroy an MTD device which was created for a map device. |
| 90 | * Make sure the MTD device is already unregistered before calling this |
| 91 | */ |
| 92 | void map_destroy(struct mtd_info *mtd) |
| 93 | { |
| 94 | struct map_info *map = mtd->priv; |
| 95 | |
| 96 | if (map->fldrv->destroy) |
| 97 | map->fldrv->destroy(mtd); |
| 98 | |
| 99 | module_put(map->fldrv->module); |
| 100 | |
| 101 | kfree(mtd); |
| 102 | } |
| 103 | |
| 104 | EXPORT_SYMBOL(register_mtd_chip_driver); |
| 105 | EXPORT_SYMBOL(unregister_mtd_chip_driver); |
| 106 | EXPORT_SYMBOL(do_map_probe); |
| 107 | EXPORT_SYMBOL(map_destroy); |
| 108 | |
| 109 | MODULE_LICENSE("GPL"); |
| 110 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); |
| 111 | MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); |