| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 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 | |
| 14 | static DEFINE_SPINLOCK(chip_drvs_lock); |
| 15 | static LIST_HEAD(chip_drvs_list); |
| 16 | |
| 17 | void 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 | |
| 24 | void 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 | |
| 31 | static 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 | |
| 57 | struct 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 | */ |
| 85 | void 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 | |
| 97 | EXPORT_SYMBOL(register_mtd_chip_driver); |
| 98 | EXPORT_SYMBOL(unregister_mtd_chip_driver); |
| 99 | EXPORT_SYMBOL(do_map_probe); |
| 100 | EXPORT_SYMBOL(map_destroy); |
| 101 | |
| 102 | MODULE_LICENSE("GPL"); |
| 103 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); |
| 104 | MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); |